CN113490627A

CN113490627A - Method for manufacturing a composite tank and composite tank obtained by said method

Info

Publication number: CN113490627A
Application number: CN202080017086.2A
Authority: CN
Inventors: L·拉尔森
Original assignee: AR Packaging Systems AB
Current assignee: GPI Systems AB
Priority date: 2019-02-26
Filing date: 2020-02-19
Publication date: 2021-10-08
Anticipated expiration: 2040-02-19
Also published as: EP3931111A1; WO2020173787A1; CN113490627B; SE543471C2; US20220135260A1; SE1950241A1

Abstract

A method for manufacturing and filling a composite tank (201), the method comprising: forming a tubular body (203) by bending a body blank (16) and merging two opposing edges of the body blank (16) together into an end-to-end joint; sealing the joint by welding a sealing strip (214) over the joint to form an intermediate tank (403; 503); sealing the top opening (211) by attaching a top sealing member (227) across the top opening (211); applying the top rim (223) to the intermediate tank (403; 503) by welding the inserted portion of the top rim (223) to the inner surface of the tubular body (203); turning the intermediate tank (403; 503) upside down and placing the intermediate tank (403; 503) on the conveyor belt (2a) with the top rim (223) resting on the conveyor belt (2 a); filling the intermediate tank (403; 503) through the bottom opening (213); sealing a bottom opening (213) of the tubular body (203) by attaching a bottom sealing member (215) across the bottom opening (213); inverting the tundish (403; 503) so that the top rim (223) is in an upwardly facing position; attaching a reclosable cap (221) at a top end of the tubular body (203). The intermediate tank is kept under a protective atmosphere starting from the filling of the intermediate tank until the bottom opening (213) of the tubular body (203) has been sealed. An assembly line (1) for manufacturing and filling composite tanks (201) is also disclosed.

Description

Method for manufacturing a composite tank and composite tank obtained by said method

Technical Field

The present disclosure relates to a method for manufacturing a composite can and packaging dry or wet goods in the composite can. A composite can as disclosed herein comprises a paperboard body made from a paperboard-based laminate that may include one or more outer polymer layers and a metal foil layer, such as an aluminum layer, in addition to a paperboard core layer. In addition, the composite can includes additional can components, such as a top sealing member, a bottom sealing member, a top rim, a reclosable lid, and optionally a bottom rim.

Background

Composite cardboard-based cans for packaging particulate or granular items sensitive to moisture and air, such as baby food, coffee, tea, cereals, tobacco, and the like, are well known in the art. In the field of packaging consumer goods, and in particular consumer goods packaged in relatively rigid composite cans, which are used as protective transport and storage containers at the retail end and as storage and dispensing containers at the consumer end, the different functions of composite cans can lead to conflicting requirements in their design. For economic and environmental reasons, the amount of material required to produce the composite tank should be as small as possible while still providing sufficient rigidity and shape stability to the composite tank. At the retail end, it is desirable that the composite tanks allow efficient and space-saving transport and storage and that the composite tanks are stackable.

Cardboard-based cans often suffer from a low shape stability of the cardboard body, which has proven to be a particular problem during manufacture and filling of the can before final sealing of the can. While providing sufficient shape stability and protection of the packaged articles in the filled and fully assembled composite can, the relatively thin paperboard body material may be damaged when exposed to forces exerted on the paperboard body during production and filling of the composite can. The inherent tension in the cardboard material may cause the tubular body formed from the rectangular cardboard blank to deviate from the intended body shape, making it difficult to handle the tubular body at high speed in the manufacturing machine. Tubular bodies that deviate from the intended shape are more susceptible to damage from grippers, conveyor belts, and other equipment in the manufacturing line. Such damage may result in an undesirably high scrap rate, as the damaged tubular body would have to be discarded. For example, tubular bodies conveyed on a conveyor belt may be packed on the conveyor belt as a dense and solid string of tubular bodies pressed against each other, thereby causing the tubular bodies to assume a deformed configuration with a shortened extension in the conveying direction and an increased extension perpendicular to the conveying direction. A tubular body deformed in this way may become stuck in the machine or may be difficult to grip and reposition with a gripper. In addition, it may be difficult to attach elements, such as top sealing members, bottom sealing members, plastic rims, etc., without damaging the exposed end edges of the tubular body. To minimize the risk of deformation or damage to the tubular body during manufacture, it may be desirable to reduce the speed of manufacture, which may result in less efficient production of the composite tank than is preferred.

Thus, there is a need for a low cost, high speed production process for composite tanks made from commonly available materials that can be run in a production line with minimal waste.

It is an object of the present disclosure to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Disclosure of Invention

The above object is achieved by a method according to claim 1 and an assembly line according to claim 10. Further embodiments are set forth in the dependent claims, the following description and the drawings.

As set forth herein, there is provided a method for manufacturing a composite can and packaging dry or wet goods in the composite can, the method comprising:

-picking a body blank from a stack of body blanks and transferring said body blank to a body forming station;

-forming a tubular body by bending the body blank and merging two opposite edges of the body blank together into an end-to-end joint, the joint extending in the height direction of the tubular body;

-sealing the joint by welding a sealing strip over the joint on the inner surface of the tubular body, thereby forming an intermediate tank;

-transferring the tundish to a top sealing station;

-sealing the top opening at the top end of the tubular body by welding a peripheral flange of a top sealing member to the inner surface of the tubular body at a distance from the top end edge of the tubular body;

-transferring the tundish to a top rim application station;

-applying a top rim to the intermediate tank by inserting at least a lower portion of the top rim into the top opening above the top sealing member;

-welding the insertion portion of the top rim to the inner surface of the tubular body;

-transferring the tundish to a conveyor belt and placing the tundish on the conveyor belt such that the top rim rests on the conveyor belt and the bottom opening at the bottom end of the tubular body faces upwards in a vertical direction;

-transferring the intermediate tank to a filling unit;

-filling the intermediate tank with the dry or wet goods through the bottom opening of the tubular body;

-subjecting the intermediate tank to a protective atmosphere during the filling of the intermediate tank, or by introducing the filled intermediate tank into a vacuum chamber to evacuate air;

-transferring the filled tundish to a sealing unit to which the filled tundish is conveyed in a closed transfer system while maintaining the protective atmosphere;

-sealing the bottom opening of the tubular body by welding a peripheral flange of a bottom sealing member to the inner surface of the tubular body at a distance from a bottom end edge of the tubular body, the sealing of the bottom opening being carried out while maintaining the protective atmosphere;

-turning over the filled and bottom-sealed tundish to bring the top rim in a vertically upward facing position and transferring the tundish to a lid attachment unit;

-attaching a reclosable cap at the top end of the tubular body, wherein an inner surface of the reclosable cap is in contact with an upper surface of the top rim.

Maintaining the intermediate tank in a protective atmosphere starting from when the protective atmosphere is created in connection with the filling of the intermediate tank until the bottom opening of the tubular body has been sealed. Thereby, air contact between the filled articles in the open intermediate container may be inhibited until the articles have been safely enclosed in the composite tank. Another technical effect is that the atmosphere in the sealing station and the sealing step can be very well controlled, since no air needs to be removed from the filled open container before the container is sealed. This has been found to be a considerable advantage, since the pressure difference in the sealing step may adversely affect the sealing process by causing turbulence in the packaging material. This turbulence may cause powder material to become trapped in the seal and potentially compromise the tightness of the seal.

The method as disclosed herein may further comprise the steps of:

-transferring the tundish to a top rim application station;

this is optional for composite cans where the top closure has a lid formed from a paperboard component.

As disclosed herein, the longitudinal axis of the tundish may be arranged in a generally vertical direction with the top end of the tubular body oriented upward in the vertical direction during transfer of the tundish from the top sealing station to the top rim application station.

In the method as disclosed herein, during the applying and attaching of the top sealing member and the top rim at the top opening of the tubular body, the top end edge of the tubular body is oriented upwards in the vertical direction and the bottom end edge of the tubular body is oriented downwards in the vertical direction. After this, the tundish, including the tubular body, top sealing member and top rim, is turned upside down so that the top end edge is oriented downwards in the vertical direction and the bottom end edge is oriented upwards in the vertical direction. The top rim attached tundish may be turned in the rim applicator or in a conventional turning apparatus downstream of the rim applicator.

By attaching the top rim to the tubular body and turning the tundish upside down before conveying it to the filling unit, the tundish will rest with the durable top rim on the conveyor belt during the transfer to the filling unit.

By attaching the top sealing member before filling the can, the risk of finding packaging material residue outside the top sealing member in the upper end of the can is eliminated, as well as the risk of particulate material contaminating the welding area and adversely affecting the quality of the top sealing member seal.

The top rim is preferably a polymeric component having a higher stiffness than the tubular body. The top rim may suitably be made by injection moulding. The top rim helps to shape and stabilize the flexible paperboard body and constitutes a protection for the top edge of the tubular body. The top rim allows the container body wall to conform to the contour of the top rim and to have a desired predetermined stable shape.

The weld seal between the top rim and the tubular body may be formed by any suitable method, such as high frequency induction welding. To achieve a tight seal, the welded seal is preferably a continuous sealing wall extending around the top opening to create a moisture-tight and preferably air-tight seal. In a composite tank produced according to the method as disclosed herein, high frequency induction welding is the preferred method for attaching tank components such as body seals, top and bottom rims, and top and bottom sealing members.

By joining the top rim to the inner surface of the tubular body by means of welding, it is possible to obtain a tighter and thinner attachment of the top rim to the tubular body than with the use of adhesive attachments previously common in the art. As set forth herein, the welded top rim is preferably a plastic rim and is arranged to extend from the inner surface of the tubular body to the inner surface of the cap in a parallel manner to the material in the tubular body. The top rim is more rigid than the cardboard-based material in the tubular body and constitutes a form-stable continuation or complement of the upper end of the tubular body and provides a first abutment surface which is resistant to deformation when pressed against a second abutment surface on the inner surface of the reclosable lid. Thereby, the composite can be repeatedly opened and closed with high tightness even after the consumer opens the can for the first time and after breaking or removing the top sealing member.

The top rim thus constitutes a rigid and form-stable part at the top end of the tubular body that can form a tight seal against the inner surface of the lid.

The top rim is preferably welded to the inner surface of the tubular body such that an upper portion of the top rim extends past the top end edge of the tubular body.

The top rim may be a profiled element comprising a circumferential flange extending outwardly from an upper edge of a lower portion of the top rim, said top rim being applied to the intermediate tank by covering an upper end edge of the tubular body by the circumferential flange. The circumferential flange constitutes a rigid protection for the cardboard material in the top edge of the tubular body.

The top rim attached to the tubular body, wherein a portion of the top rim extends outwardly from the top opening in the tubular body in the height direction of the tubular body, forms a rigid wear resistant and shape stable support on which the tundish may rest after having been turned 180 ° to place it upside down on a conveyor belt for transfer to the filling unit. The intermediate tank may form a dense queue or slide on a conveyor belt without causing deformation of the cardboard material in the tubular body or causing damage to the top edge of the tubular body.

The top edge may have any suitable cross-sectional profile as long as the top edge can be assembled with at least a portion of the top edge inside the top opening. The lower portion of the top rim may have a different thickness than a different portion of the top rim. It may be preferred that no part of the top rim is arranged to extend downwardly over the outer surface of the main body tube. A top rim having a generally I-shaped or L-shaped profile may be preferred as it may be easily inserted into the top opening and attached to the inner surface of the tubular body by welding and pressure application perpendicular to the inner surface of the tubular body.

As set forth herein, the paperboard body is supported and protected by the top edge during subsequent process steps without risking damage to the exposed paperboard edges. The top rim provides support and protection for the tundish during process steps such as filling and sealing of the bottom opening, degassing, etc., which steps may be performed with the tundish resting on the top rim.

The top rim makes it possible to fill the container from the bottom end after the top sealing member has been applied at the top opening. If the top end sealing member is applied instead after the composite can has been filled with the contents in the form of particles or granules, the turbulence created when pushing the top sealing member into the container body may cause some of the particles or granules to fall out of the tubular body and end up in the space between the top sealing member that falls outside the top sealing member and the top end edge of the tubular body. A user who opens the composite can and finds the exposed top sealing member soiled with packaging material will generally consider the can less than sanitary as desired. In addition, some of the packaging material may be trapped in the welded seal between the top sealing member and the inner surface of the tubular body, making the seal less tight than desired and making it difficult to accurately control the strength of the seal.

The method as disclosed herein may further comprise:

-applying a bottom rim to the bottom end of the bottom-sealed intermediate tank;

-placing the bottom sealed tundish on a conveyor belt during the transfer of the tundish to the lid attachment unit, the bottom rim resting on the conveyor belt.

The bottom rim is applied in the form of a closed ring which extends in a bottom ring plane and has an outer contour and an inner contour and has a height in a height direction perpendicular to the bottom ring plane. The bottom edge has an upper edge portion and a lower edge portion in a height direction of the bottom reinforcing edge. The bottom edge may be applied by:

-inserting the top rim portion of the bottom rim, and optionally also the lower rim portion of the bottom rim, into the tubular body at the bottom end edge, wherein a lower end edge of the bottom reinforcing rim is outside the container body or flush with the bottom end edge of the tubular body; and

-attaching the bottom rim to the inner surface of the tubular body, preferably by welding, such as by high frequency induction welding.

The advantages of providing a bottom rim to the composite tank are similar to those obtained with a top rim. In a tundish that has been filled from the bottom end and sealed with a bottom sealing member, the bottom rim enhances the shape stability at the bottom end of the tubular body and protects the bottom end edge of the paperboard material in the tubular body from tearing if the filled and bottom sealed tundish is transported on a conveyor belt while standing on the bottom rim. In the fully assembled composite can, the bottom rim continues to act as a support element that protects the paperboard material at the bottom end of the composite can from moisture that may be present on a countertop or other surface upon which the can is placed by a user. When stacking the composite tanks on top of each other, the bottom rim may further form a rigid and form-stable support element cooperating with a mating stacking element at the upper portion of another composite tank.

After applying the bottom sealing member to the filled intermediate tank, the sealed and filled intermediate tank may be turned 180 ° in the sealing unit or in a conventional turning apparatus downstream of the sealing unit.

A method as disclosed herein may comprise simultaneously treating two or more intermediate tanks, such as four intermediate tanks, during one or more process steps, such as:

-sealing the top opening;

-applying the top rim;

-welding said top rim;

-turning the tundish through 180 °;

-filling the intermediate tank;

-sealing the bottom opening;

-turning the filled and bottom-sealed tundish through 180 °; and

-attaching the reclosable cap.

Also disclosed herein is an assembly line for manufacturing composite tanks and filling dry or wet goods in composite tanks, for example according to the method as disclosed herein. The assembly line comprises a plurality of machine units connected by a conveyor belt, wherein the machine units comprise:

-a body forming station;

-a filling unit;

-a sealing unit; and

-a lid attachment unit.

In an assembly line as disclosed herein, a gas box may be arranged between the filling unit and the sealing unit.

The body forming unit of the assembly line may include:

-a body blank picking station;

-a body forming station;

-a top sealing station; and

-a top edge application station.

The sealing unit of the assembly line may comprise a can sealing station and optionally an edge application station.

Any machine unit of the assembly line may be arranged at least partly in the outer housing. Further, any machine unit or part of a machine unit may be arranged to operate in a modified atmosphere (also referred to herein as a protective atmosphere) in the outer housing. As disclosed herein, the sealing unit may be arranged in an outer housing and may be arranged to operate in a protective atmosphere in said outer housing. Further, any of the tank component applicators as disclosed herein may be at least partially disposed in an inner housing inside an outer housing.

The method as disclosed herein may comprise a degassing step performed in conjunction with the filling step. The degassing step may comprise supplying a protective gas to the product stream during the filling step. The protective gas may be nitrogen, carbon dioxide or a mixture of nitrogen and carbon dioxide. The protective gas may be blown into the dry or wet product stream during filling of the intermediate tank before said product stream reaches the inner compartment in the intermediate tank.

Alternatively or additionally thereto, the sealing of the bottom opening can be carried out in a protective atmosphere. When the product stream is treated with the protective gas in the filling step, the filled intermediate tank is preferably transferred to a closing step in a sealing unit, while maintaining the protective atmosphere, for example by moving the intermediate tank through a tunnel filled with the protective gas. Alternatively, the filled intermediate tank may be introduced into a vacuum chamber to evacuate the air, after which the filled intermediate tank is subjected to a protective atmosphere and sealed.

The application of the tank components, such as the top sealing member, the bottom sealing member, the top rim and the bottom rim, may be performed using an attachment unit comprising a welding unit, such as a high frequency induction welding unit, configured to fasten the components to the tubular body during production of the composite tank. The welding unit may comprise an induction welding energy generator for softening or melting a weldable layer forming part of the tubular body and/or the applied tank part. The apparatus may further comprise a transport mechanism configured to transport the tundish flow to and from the attachment unit. The conveying mechanism may comprise, in sequence, a feeding arrangement, a main conveyor belt member and a movable clamping arrangement. The feeding arrangement may be configured to transfer the intermediate cans successively one after the other to the main conveyor member, and the clamping arrangement may be configured to transfer the intermediate cans from the main conveyor member to the welding unit. The apparatus may be arranged such that, during normal operation of the apparatus, the intermediate tanks are lined up close to each other at an upstream side of the feeding arrangement, the feeding arrangement being configured to separate adjacent intermediate tanks from each other in the feeding direction by increasing the feeding speed of each individual intermediate tank along the feeding arrangement, and thereby increasing the distance between adjacent intermediate tanks fed along the feeding arrangement. The main conveyor member may be configured to operate at a delivery speed that approximately corresponds to the release speed of the intermediate cans as they are fed out of the feeding arrangement and is coincident with respect to said release speed, such that the intermediate cans transferred to and along the main conveyor member remain separated. The movable gripping arrangement may be configured to grip at least two intermediate tanks, such as four intermediate tanks, and to transfer these simultaneously from the main conveyor member to the attachment unit, which is preferably configured to simultaneously secure tank components to each of the simultaneously transferred intermediate tanks.

The feed arrangement may comprise a feed screw member provided with an increasing pitch such that the feed speed of each individual tundish, and the distance between adjacent tundish, increases in correspondence with the increasing pitch when the tundish is conveyed by the feed screw member. Such a feed screw member creates a defined distance between the intermediate pots, allowing a controlled positioning and a proper clamping of the intermediate pots.

The feed screw member allows a controlled feed speed at the inlet of the feed screw member. By adjusting this inlet speed with respect to the speed of conveying the intermediate tank towards the feed screw member, e.g. by making the inlet speed only slightly lower than the conveying speed of the conveyor belt arranged to convey the intermediate tank to the feed screw member, it is possible to prevent the filled open intermediate tank from colliding with the slowly moving stream of intermediate tanks at high speed, which open intermediate tanks will approach and join the upstream stream of intermediate tanks more smoothly.

It may be preferred that the feed screw arrangement comprises two feed screw members arranged in parallel along each side of the stream of intermediate tanks, such that each intermediate tank is conveyed between the two feed screw members arranged to operate in cooperation with each other. This provides a secure feed grip of the tundish and reduces the risk of the tundish slipping through its space in the feed screw.

The main conveyor member may comprise a slide guide configured to support the tundish and allow it to slide in the conveying direction when transferred to the main conveyor member, and carrying bars distributed at defined distances along the moving and conveying portion of the main conveyor member for pushing the containers along the slide guide. In this way, the tundish can be prevented from slipping relative to regularly moving parts, such as conveyor belts, which could result in randomly varying distances between adjacent tundish parts, causing problems in the subsequent clamping step. The use of a sliding guide and carrier bar as set forth herein further improves the positioning of the tundish prior to clamping, as the distance between adjacent conveyed tundish delivered to the clamping arrangement is predefined and constant.

The conveying mechanism may further comprise an inlet conveyor belt member configured to feed the containers to the feeding arrangement. The entrance conveyor member may be configured to operate at a conveying speed that approximately corresponds to an initial feeding speed at the entrance side of the feeding arrangement and is coincident with said initial feeding speed. This provides a smooth transition of the tundish between the inlet conveyor member and the feeding arrangement. Preferably, the inlet conveyor belt member also forms a support for the intermediate cans when fed along the feeding arrangement. The inlet conveyor belt member may be configured to allow the intermediate tank to slide while being supported as its feed speed increases during feeding along the feeding arrangement. The entrance conveyor member may comprise an endless steel belt conveying and supporting the tundish.

The attachment unit may comprise at least two sub-units, each sub-unit comprising a cavity adapted to receive at least one end portion of the intermediate tank to which a tank component, such as a top sealing member, a bottom sealing member or a rim, is to be fastened, wherein an induction welding energy generator, such as a coil, extends around the cavity so as to circumferentially surround the intermediate tank placed in the cavity along a distance corresponding to a circumferential edge of the tank component placed in its intended fastened position in the intermediate tank, each unit further comprising a tank component positioning device configured to position the tank component in the intended fastened position.

The positioning means may take the form of a pressing piston which positions the tank component inside the tubular body of the tundish and thereafter expands radially to exert a radially outwardly directed pressing force on the inserted tank component and press a portion of the tank component against the inner surface of the tubular body. The tank component is held under pressure against the inner surface of the tubular body while welding the tank component to the tubular body.

The positioning device may comprise two parts that are axially movable relative to each other:

a substrate comprising or consisting of a rigid material, and

-an elastically deformable piston skirt.

The axial movement between the two parts of the positioning device can be accomplished by means of a first piston and a second piston, which extend in the axial direction, wherein the second piston is coaxial with the first piston. The base plate is connected to an end portion of the first piston such that a covered surface of the base plate is perpendicular to the axial direction. The piston skirt is connected to an end portion of the second piston. The first and second pistons are configured to be axially displaceable in synchronism with and independently of each other. The end portion of the second piston is configured to be closer to the end portion of the first piston when the piston skirt is in the expanded state than in the non-expanded state.

When the tank part is inserted into the attachment position in the tubular body, the first and second pistons are axially displaced in synchronism with each other, i.e. move together as a single unit. When transforming the piston skirt into the expanded state, the first piston and the second piston are displaced independently of each other such that the second piston is displaced in the axial direction relative to the first piston. Thereby, the piston skirt is pressed down on the base plate and flattened, so that the outer peripheral portion of the piston skirt is caused to assume an expanded state. The resiliently deformable piston skirt automatically returns to the non-expanded state once the pressure exerted on the piston skirt from the first piston and the second piston ceases after the container element is applied at the desired location inside the container body.

The base plate has a cover surface with a circumferential edge comprising a plurality of side edge portions connected by corner portions. The piston skirt covers a surface of the base plate opposite the cover surface.

As described herein, the piston skirt may transition between a non-expanded state and an expanded state. The piston skirt has an outer peripheral portion that is located at a circumferential edge of the cover surface of the base plate in the unexpanded state and is located at least partially outside the circumferential edge of the cover surface of the base plate in the expanded state.

The outer peripheral portion of the piston skirt preferably has a shape in the non-expanded state corresponding to the shape of the peripheral edge of the mantle surface.

At least one of side edge portions of the circumferential edge of the base plate may include a bent section bent from the circumferential edge of the cover surface in the inward direction, and at least one corresponding side portion of the outer circumferential portion of the piston skirt may include a bent section bent from the outer circumferential portion of the piston skirt in the inward direction.

The piston skirt is disposed on top of the base plate so as to cover an upper surface of the base plate opposite the cover surface. When the piston skirt is in the non-expanded state, it will not contact the can part or at least not exert any force on it during insertion of the can part into the attachment position inside the tubular body. When the tank part has reached the attachment position, the piston skirt is caused to expand in a radial direction, thereby pressing the edge portion of the tank part circumferentially against the inner surface of the tubular body. In this expanded state of the piston skirt, a cross-sectional area defined by the outer peripheral portion of the piston skirt is larger than a cross-sectional area in a non-expanded state of the piston skirt.

By providing at least one curved section of the circumferential edge of the cover surface of the base plate and a corresponding at least one curved section of the outer circumference of the piston skirt, the risk of the positioning unit hitting the upper edge of the tubular body and thereby damaging the tubular wall of the tubular body when inserting the tank part can be greatly reduced or eliminated.

During transition to the expanded state, the piston skirt will be flattened and any one or more of the inwardly curved sections will simultaneously straighten out, at least to the extent that the outer peripheral portion of the piston skirt extends beyond the peripheral edge of the cover surface. Thus, by carefully selecting the shape and/or material properties of the piston skirt in the non-expanded state, a desired change in shape during the transition may be obtained. The material for the piston skirt may be any useful elastically deformable wear and heat resistant material as known in the art, such as natural or synthetic rubber materials, e.g. polyamide, polyurethane, polyester, etc.

The method as disclosed herein may be implemented at least in part using a device having components as set forth above, and may include the steps of:

-transferring the intermediate cans successively one after the other from the feeding arrangement to the main conveyor member,

-transferring the tundish from the main conveyor member to the attachment unit by means of a movable clamping arrangement,

-separating adjacent containers from each other in the conveying direction by increasing the feed speed of each individual intermediate tank along the feeding arrangement, and thereby increasing the distance between adjacent intermediate tanks fed along the feeding arrangement,

-operating the main conveyor member at a delivery speed which approximately corresponds to the release speed at which the intermediate pots are delivered from the feeding arrangement and which corresponds with respect to said release speed, such that the intermediate pots transferred to and along the main conveyor member remain separated,

-gripping at least two intermediate tanks by means of a movable gripping arrangement and transferring these simultaneously from the main conveyor member to the attachment unit, and

-simultaneously fastening tank components to each of the simultaneously transported intermediate tanks.

The movable clamping arrangement may comprise a first and a second clamping element arranged to operate on opposite sides of the stream of intermediate tanks, wherein the clamping elements are movable towards and away from each other to clamp and release the intermediate tanks, respectively, and wherein the clamping elements are movable along the stream of intermediate tanks in a synchronized manner between the main conveyor member and the welding unit to simultaneously transfer two or more intermediate tanks, each clamping element being provided with at least two recesses, such as four recesses, to clamp each side of a corresponding number of simultaneously clamped intermediate tanks, wherein the distance between the recesses of the clamping elements corresponds to the distance between intermediate tanks positioned on the main conveyor member during operation of the apparatus.

The movable clamping arrangement may be configured to clamp four containers and simultaneously transfer the four intermediate tanks from the main conveyor member to the welding unit, wherein the welding unit is configured to simultaneously secure tank components to each of the four intermediate tanks.

The feeding arrangement may comprise a second movable clamping arrangement configured to clamp at least two intermediate tanks and to transfer these simultaneously from the attachment unit to the outlet conveyor member, and an outlet conveyor member arranged downstream of the attachment unit.

A slide guide, such as a stationary slide plate, may be arranged at the end of the outlet conveyor member, so that the tundish may be slid on the slide plate from the outlet conveyor member to a further conveyor member for conveying the tundish to a subsequent machine unit in the production line. Such a slide reduces the feed speed of the tundish and reduces the distance between the tundish. Thus, the intermediate tanks are again lined up next to each other continuously in the same way as at the upstream side of the feed arrangement.

As set forth herein, the attachment unit may be disposed in an outer housing and may create a protective atmosphere inside the outer housing. The outlet port of the intermediate tank may be arranged in the outer housing, wherein the size of the opening is adapted to the size of the intermediate tank being treated. The outlet port may comprise a short tunnel arranged at the end of the outlet conveyor belt member, wherein the slide plate constitutes a floor in the tunnel. The outlet conveyor pushes the tundish onto the fixed slide plate, thereby creating a continuous flow of tundish through the outlet tunnel. Since the size of the outlet tunnel is adapted to the size of the intermediate tank, the tank fills the cross section of the outlet tunnel, whereby the outlet port becomes relatively gas-tight during operation of the device without any need for additional equipment. The provision of a fixed slide plate in the outlet tunnel ensures that the intermediate tank always acts as a "plug" in the outlet tunnel and prevents the escape of protective gas and the entry of air due to the outlet in the outer housing. In a corresponding manner, the shape and size of the inlet port with respect to the inlet tunnel into the outer casing may be adapted to the size and shape of the intermediate tank produced on the assembly line as disclosed herein. However, since the entrance conveyor may already be arranged in a protective atmosphere, it is often sufficient to arrange the hatch of the reclosable lid at the entrance to the attachment unit in order to allow closing of the entrance port as required.

When transporting an already filled but not yet sealed intermediate tank, it is desirable to maintain the protective atmosphere intact from where it is created until the bottom of the intermediate tank has been closed over the filled contents. It is possible that a protective atmosphere has been created during the filling phase, for example by blowing a protective gas into the material flow before the material reaches the tank. Alternatively, the filled intermediate tank may be introduced into a vacuum chamber to evacuate air, followed by subjecting the tank to a modified atmosphere and applying the bottom sealing member.

In all cases, the filled cans were transported to the sealing unit in a closed transfer system while maintaining a protective atmosphere. To ensure that no protective gas escapes at the interface between the transfer system and the canister sealing unit, close fitting inlet and outlet tunnels may be arranged at the inlet and outlet of the sealing unit as disclosed herein.

A method as disclosed herein may include applying a scoop in a compartment formed between a top sealing member and a reclosable lid. The scoop is preferably applied to the intermediate pot after filling and before attaching the reclosable lid at the top end of the tubular body. The scoop may be applied directly on the top sealing member or may be placed in a scoop holder arranged above the top sealing member. The scoop holder may be formed as an integral part of the top rim or may be a complementary part of the top rim. The ladle holder disposed on the top rim may include a scraper bar for leveling the scooped excess contents from the ladle head. The scoop handle may be configured to be held in a substantially horizontal position above the top sealing member, such that the scoop is retained in the substantially horizontal position by the scoop handle. The scoop head and the scoop holder may be arranged such that the scoop head may be snapped into engagement with the scoop holder, for example by the scoop head being provided with one or more protruding elements, such as one or more bumps or ridges, which snap under an edge of the scoop holder when the scoop head is pressed into the scoop holder. The snap-in engagement between the scoop head and the scoop holder ensures that the scoop is always securely held in a predetermined position in the scoop holder without rattling and without the scoop handle falling down into the contents of the composite can once the user removes the top sealing member.

The reclosable lid may have a scoop holder in the form of a clip arranged on an inner surface of the reclosable lid. A scoop holder on the inner surface of the reclosable lid may be provided as an alternative or supplement to the scoop holder on the top rim.

The scoop may be placed in the can as such, or may be prepackaged in a hygienic wrap, such as a plastic bag.

The barrier properties of the cans as disclosed herein can be designed to meet different tightness requirements depending on the product packaged in the can. By way of example, in cans for dry peas, a lower barrier level may be acceptable than in cans for e.g. infant formula, which is highly sensitive to oxygen and moisture exposure. The combination of the gas-impermeable gasket seal between the upper edge of the top rim and the inner surface of the reclosable lid and the gas-impermeable welded seal between the top rim and the inner surface of the tubular body may also provide excellent barrier properties to the can after the top sealing member has been removed.

The cans produced by the methods as disclosed herein may preferably have barrier properties that remain largely unchanged even after the top sealing member is broken or removed. In other words, the contents of the closed can may be protected equally well or nearly equally well, whether the top sealing member has been opened or not. This also means that the seal created between the re-closable lid and the top rim and the welded seal between the top rim and the inner surface of the can preferably have barrier properties that provide the same level of protection to the package contents as the top sealing member is not breached.

As set forth herein, the welding process, particularly the high frequency induction welding process, provides a highly controlled way of producing a joint having a predetermined tightness between the top rim and the thermoplastic layer of paperboard-based material in the tubular body. The joint is made by supplying energy to heat and locally soften or melt one or more thermoplastic components in the plastic rim and/or on the inner surface of the tubular body and by pressing the plastic rim and the tubular body together in a direction perpendicular to the inner surface of the tubular body. The thermoplastic material used to create the weld seal may be provided by the plastic rim, a thermoplastic film or coating on the inner surface of the tubular body, or both the plastic rim and the thermoplastic film or coating on the inner surface of the tubular body. It may be preferred that the plastic rim is made of a thermoplastic material. The thermoplastic rim may be produced by any suitable melt forming process known in the art, such as injection molding. By controlling the amount of energy supplied, the pressure applied and the welding time, it is possible to adapt the welding process to the welding material and to obtain a welded joint with the required tightness. Thus, the welding process is accurate and predictable, and is an efficient way to produce a reliable seal with a predetermined tightness.

After filling the can with the packaged product, the bottom end is closed to seal the product in the internal compartment of the can. As set forth herein, closing of the bottom end is performed by attaching a bottom sealing member to the inner surface of the tubular body. The bottom sealing member is preferably attached at a short distance inward from the bottom end edge of the tubular body to provide stackability and/or to facilitate application of the bottom rim at the bottom end of the tubular body. The insertion of the bottom sealing member may create a pressure slightly above ambient pressure inside the sealed intermediate tank. It has been found that such overpressure can cause a slight outward bulge in the top sealing member. In a two-ply top seal member having a partially cut tear strip in the upper outer layer of the seal member, it has been found that the slight outward bulge in the top seal member helps to raise the gripping end of the tear strip from the underlying layer. In this way, it is easier to grasp the gripping end, thereby facilitating the pulling apart of the top sealing member.

The bottom sealing member may be made of any suitable material, such as paperboard, plastic, metal, and laminates of such materials, with paperboard-based bottom sealing members generally being preferred. The paperboard-based bottom sealing member may be made of a laminate material including a paperboard layer, a metal foil layer, and a thermoplastic polymer layer disposed at an interior surface of the paperboard layer facing the interior of the container body, with the metal foil layer disposed between the paperboard layer and the thermoplastic polymer layer. A further thermoplastic polymer layer may be arranged at the outer surface of the paperboard layer. The bottom sealing member may be attached to the inner surface of the tubular body by welding, such as high frequency induction welding. The bottom sealing member is shaped prior to or during insertion into the bottom opening by bending the peripheral edge portion outwardly from the plane of the bottom sealing member to create a flange that is aligned with and can be welded to the inner surface of the tubular body. The weld seal between the bottom sealing member and the container body wall is far less sensitive to contamination of the packaging material than the weld seal between the top sealing member and the inner surface of the tubular body. The cardboard-based bottom sealing member is typically thicker and more compressible than the top sealing member and it is easier to form a tight seal between the bottom sealing member and the tubular body. The amount of packaging material that may fall out of the intermediate tank when the bottom sealing member is inserted into the bottom opening is very small. Since the bottom sealing member will only be inserted a very small distance in the tubular body, the insertion step will only generate a minimum of turbulence at the surface of the packaging material. The amount of material lost during the closing step is thus minimal. Any material that ends up falling outside the bottom sealing member after the intermediate tank has been closed and sealed can be easily removed and does not cause the fully assembled composite tank to appear dirty.

Alternatively, the bottom end of the composite tank may be closed by any suitable method as known in the art, such as by folding and sealing an end portion of the container wall.

After sealing the bottom and optionally attaching the bottom rim to the bottom end of the composite can, the composite can is transferred in a conventional manner to equipment such as a palletizing unit, weighing unit, leaflet inserter, spoon inserter, etc.

The lid applying step of the method as disclosed herein may further comprise applying the frame structure by mechanically attaching the frame structure to the top rim. The mechanical connection between the top rim and the frame structure may be accomplished by providing mating profiles on the top rim and the frame structure. Such mating profiles preferably include snap features such as interengaging ridges and tracks or projections and holes/cavities or the like.

The frame structure may be configured to cooperate with an insert cover or hinged cover to hold the cover in a closed position, wherein an inner surface of the cover is in direct contact with an upper surface of the top rim. The frame structure may be applied together with the cover.

The attachment between the frame structure and the top rim may be achieved by forming a snap-in connection between the frame structure and the top rim.

The mechanical connection between the top rim and the frame structure preferably means irreversibly: once established, a connection can only be broken by destroying or destroying portions of the connection.

The frame structure may form part of a cover part, said cover part further comprising a cover part connected to the frame structure by a hinge. The lid portion may be a complete lid or may simply be a portion of a lid that is assembled with one or more additional lid portions to form the container lid. By way of example, the lid portion may be an outer lid portion that defines the shape and size of a portion of the lid that is exposed to the exterior of the composite can and is combined in the container lid with an inner lid portion (such as an inner sealing member) that provides an abutment surface that cooperates with a corresponding abutment surface on the top rim to form a gasket seal between the lid and the top rim. The inner sealing member may take the form of a planar disc and may be made of cardboard, plastic or any suitable laminate, and may comprise a resiliently compressible material, such as a natural or synthetic foam material, or other resiliently compressible polymeric material that may assist in a tight seal between the lid and the top rim. The inner sealing member may be attached to the outer cap portion by gluing or welding. However, it may be preferred that the inner sealing member is mechanically attached to the outer lid portion, such as by snapping into a groove extending along an edge of the outer lid portion on an inner surface of the outer lid portion.

It may further be advantageous to attach the inner sealing member to the outer cap portion under tension, since it has been found that a tensioned inner cap portion has an enhanced sealing capability.

It is the inner surface of the lid that forms the seal against the abutment surface of the top rim when the lid portion constitutes a complete lid. The inner surface of the lid may be coated with a resiliently compressible material at least in the area corresponding to the abutment surface of the top rim, or may comprise a layer of resilient material on the inner surface of the lid.

By providing the lid, the frame structure or the lid component as separate parts from the top rim, these parts can be attached to the top rim after the intermediate tank has been filled and the bottom end has been closed. The cover, frame structure or cover component may have a three-dimensional contoured shape, thereby having stacking features, decorative embossment elements, locking elements, and other distortions and irregularities. In addition, the cover or cover portion may have a non-planar surface, such as a rounded surface or an irregularly shaped surface. All such three-dimensional features make the intermediate composite tank very difficult to handle during the underfill process, as the intermediate tank may not be able to safely rest on the non-planar upper surface formed by the lid or lid component. Plastic parts with complex three-dimensional shapes are quite expensive to manufacture and can be easily damaged in the process when transferring the intermediate tank between different processing stations, gripping and repositioning the tank, attaching the tank parts, filling and closing the tank. By applying the frame structure or the cover part after filling and closing the tank, the number of tanks that are damaged in the process and have to be discarded can be reduced. An upper closure comprising a lid and a two-part rim/frame configuration as disclosed herein may be used to keep waste at a lower level than is possible with a conventional single-part rim configuration. The top rim as disclosed herein has a simple shape without protruding features that may be damaged during the production process and may be used as a support and reinforcement element of the tubular body during the manufacturing and filling process as set forth herein. In the assembled composite can, the top rim helps to stabilize and shape the cardboard-based body during transport and storage.

After the inner packaging compartment in the tubular body has been filled with the packaged product and the bottom end of the tubular body has been closed, a reclosable lid may be applied to the upper end of the intermediate tank.

The reclosable lid may be a separate part of the composite can that can be completely removed when opening the can. Alternatively, the cover may be attached to the frame structure by means of a hinge, as set forth herein. The hinge may be a living hinge, i.e. a bendable connection between the cover and the frame structure. The living hinge may be integral with the cover and/or the frame structure or may be a separately formed element attached to the cover and the frame structure. Alternatively, the hinge may be a two-part hinge, wherein the first hinge part is arranged on the cover and the second hinge part is arranged on the frame structure. A two-part hinge construction may alternatively be used to attach the lid directly to the top rim.

If the resealable cap includes an outer portion and an inner sealing disk, the inner sealing disk is preferably attached to the outer portion of the resealable cap portion prior to attaching the resealable cap or cap component to the intermediate tank. Although less preferred, the inner sealing disk may alternatively be attached to the outer portion of the resealable cap after attachment of the resealable cap or cap component to the intermediate tank.

In a composite tank produced according to the method as disclosed herein, the inner profile of the top rim defines the shape and size of the access opening, whereby the access opening is smaller than the top opening of the tubular body. The open area of the access opening is preferably 85% to 99% of the area of the top opening of the tubular body, such as 90% to 98% of the area of the top opening of the tubular body, or 94% to 97% of the area of the top opening of the tubular body. The top rim is preferably built into the tank opening as little as possible so that the size of the access opening is maximized. The thin top rim and large access opening allow the contents of the can to be easily accessed and contribute to facilitate scooping or pouring of the contents from the can. The thin inner top rim minimizes the risk of particulate material adhering to the surface of the rim during scooping or pouring of the contents from the can or when moving or transferring the closed can between dispensing scenarios. A user opening the can and revealing a soiled top rim may feel that the can is messy and less than sanitary as desired. It is often desirable to keep the packaged product away from the access opening where it may be more exposed to contamination, as it may be more easily contacted by the hands of a person opening the can and removing the contents through the access opening. Contaminated contents of the can that adhere to the top rim may fall back into the can and in turn may contaminate the remaining contents of the can.

If the package can is provided with a frame structure mechanically connected to the top edge, it may be preferred that no part of the frame structure extends into the access opening and detracts from the area of the access opening. The frame structure may then be used to provide features such as a lid hinge, a mechanism for holding the lid in a closed position over the access opening, locking elements, stacking elements, and the like.

The top rim or frame structure may further be provided with means for holding the lid in the closed position, wherein the inner surface of the lid is in direct contact with the upper edge of the top rim. As is known in the art, such mechanisms may be comprised of snap-lock elements including mating ridges and grooves, female/male locking elements, etc. on the rim or frame structure and on the cover. In addition to this, the closing arrangement on the composite tank preferably also comprises a locking arrangement.

The locking arrangement may comprise: a first locking element arranged on the frame structure (if present), on the tubular body or composite tank or on the top rim; and a second locking element arranged on the can lid. The first and second locking elements may be cooperating locking elements, such as female/male locking elements, including hooks and other protrusions arranged to inter-engage with ridges, hooks, tracks, holes, cavities, loops, etc.

The locking arrangement may comprise at least one locking tab permanently joined to the top rim or frame structure, such as at a front edge portion and/or a side edge portion of the access opening of the can. The locking tab has a free end portion extending in the height direction of the composite can towards the reclosable lid. The free end portion of the locking tab comprises a first locking element arranged to cooperate with a second locking element on the outer surface of the reclosable lid. Preferably, the locking tab has an extension in the height direction of the composite can that allows the free end portion to reach a distance above the top portion of the outer lid surface, such that the first and second locking elements may be arranged to fit over the top portion of the outer lid surface at the edge of the reclosable lid. When the locking tab is in the closed position (with the first and second locking elements engaged with each other), the lid and top rim or frame structure are securely clamped together and held under tension. The locking flap is preferably hingedly connected to the top rim or frame structure, preferably by means of a living hinge integrally formed with the top rim or frame structure and the locking flap.

The concave gripping region may be disposed on an outer lid surface of the top portion of the lid portion. The recessed gripping area is arranged at a free end portion of the locking tab and is for providing access to the free end portion of the locking tab in a direction perpendicular to a height direction of the cover member. Thereby, even if no part of the locking flap in the closed position extends beyond the outer lid surface of the top part of the lid part in the height direction of the lid part, the locking flap can be easily manipulated.

Alternatively, although generally less preferred, the locking arrangement may be provided by a locking tab or clasp closure extending from an edge on the lid, such as a forward edge on the lid, and comprising at least one locking element which may be secured in or on a corresponding locking element on the top rim or on the frame structure.

The locking element is preferably designed to allow repeated opening and closing of the locking arrangement. Manipulation of the locking arrangement may be facilitated by means of gripping means, such as finger grips, friction enhancing elements, pull tabs, etc.

One or more stacking members at the can opening may be peripherally disposed on the lid and/or a frame structure connected to the top rim surrounding the access opening in the package can. The lids may be provided with cooperating stacking members arranged on the upper outer surface and the inner lower surface of each lid, thereby enabling the lids to be stacked individually prior to application to the intermediate can, for example in a process for producing packaging cans as disclosed herein. In a similar manner, cover parts comprising cover parts hingedly connected to a frame structure may be provided with cooperating stacking members, thereby enabling the cover parts to be stacked individually.

The stacking member at the can opening may take the form of a peripheral ledge on the outer lid surface or on the top rim or on a frame structure connected to the top rim. The bottom edge or rim of the first can rests on the peripheral ledge when stacked one on top of the other.

A lid component of a composite tank as disclosed herein has a lateral direction and a height direction perpendicular to the lateral direction, and comprises a lid portion comprising a top portion and a sidewall portion, and a frame structure. The top portion has an outer cap surface and an inner cap surface opposite the outer cap surface, and a peripheral edge surrounding the outer cap surface. The frame structure includes upper and lower portions in a height direction and has a lower edge surface. The stacking member may be disposed on the outer lid surface, the stacking member on the outer lid surface including a lid member stacking step and a can stacking step. The tank stacking step includes a first support surface disposed at a first level lower than a highest level of the outer lid surface in a height direction of the lid member, and the lid member stacking step includes a first support surface disposed at a second level lower than the highest level of the outer lid surface and lower than the first level in the height direction of the lid member. The lid member stacking step is disposed on a peripheral edge of the outer lid surface outside the tank stacking step in a lateral direction of the lid member, and the frame structure is adapted to be fitted on and supported by the lid member stacking step. The tank stacking step is adapted to receive and support the bottom edge of the composite tank.

The lid portion and frame structure of the lid member as disclosed herein may be fully separable portions, partially separable portions, or fully inseparable portions. In a cover part with completely detachable parts, the parts are detachably and reclosable connected to each other in the closed configuration of the cover part. In a lid part having parts that are partly separable, the parts are connected to each other by a hinge and can be moved between a closed configuration of the lid part and an open configuration of the lid part by pivoting about the hinge. The cover member having the inseparable portion is one in which the frame structure forms an integral continuation of the side wall portion of the cover portion.

As set forth herein, the bottom rim may be attached to the tubular body of the composite tank at the bottom end of the tubular body. In a composite can having a stacking step on a reclosable lid or on a lid component comprising a reclosable lid, the bottom rim is adapted for stacking cooperation with the can stacking step on a top portion of the lid or lid component.

In a composite tank as disclosed herein, the lower end surface of the bottom rim may be adapted for stacking cooperation with the first support surface of the tank stacking step, and the inner wall of the bottom rim may be adapted for stacking cooperation with the second support surface of the tank stacking step. When stacking a second can as disclosed herein on a first can as disclosed herein, the lower end surface of the bottom rim of the second can rests on the first support surface of the can stacking step of the first can, and the second support surface of the can stacking step limits lateral movement of the second can relative to the first can.

As set forth herein, the stacking member is disposed on an outer lid surface of the lid component and includes a lid component stacking step and a container stacking step, wherein the lid component stacking step is disposed laterally outside and below the tank stacking step. By arranging the stacking members at the extreme edges of the cover portion, the stacking members minimally encroach on the top surface of the cover, and a large central area of the cover is available for display purposes, such as for communicating information, branding, and/or for design purposes. Since the stacking step is arranged at a level lower than the central area of the top surface of the lid portion, it is inconspicuous and its technical characteristics as a function of the stacking member may not become immediately apparent to the end user of the composite tank. When the cans are placed where they can be seen, such as on a counter top in the user's home or on a shelf in a store, the composite can may be perceived as having a more attractive and "designable" appearance, with less technical characteristics that may be beneficial.

When stacked together, the cover members provided with stacking steps as disclosed herein nest with each other such that they can be stacked in a space-saving yet efficient and stable manner, wherein each cover member increases the height of the stack by less than the height of the cover member. Thus, the combined height of the stacked cover members is less than the sum of the individual heights of the cover members. The space-saving stacking configuration is advantageous for transport and storage purposes and during production of the composite tank. The space-saving stacking makes the supply of cover members more efficient during production, since the cassettes for cover members can accommodate a larger number of cover members and require less frequent refilling.

Thus, the double step configuration of the peripheral portion of the lid member provides a stable and efficient stacking of the individual lid members and the composite cans comprising the lid members. Providing the lid part and the composite can with separate stacking steps on the outer surface of the lid part makes it possible to size each stacking step and configure it as optimal for a specific stacking purpose.

The cover portion of the cover member is provided with two distinct and distinct stacking members arranged as two generally L-shaped stacking steps at the peripheral edge of the outer cover surface. The lid member stacking step is located outside the tank stacking step as viewed in the lateral direction of the lid member, and is located below the tank stacking step as viewed in the height direction. When the second cover member is stacked on the first cover member, the cover member stacking step of the first cover member fittingly receives the lower portion of the frame structure of the second cover member, so that the lower portion of the frame structure is fitted on the cover member stacking step in a nested manner.

The lid member stacking step and the can stacking step may each include a second support surface.

The second support surface of the cover member stacking step may be arranged to support an inner wall of the lower portion of the frame structure, i.e. to support the second cover member in a lateral direction of the cover member. Thus, when the cover members are stacked on each other on a horizontal surface, the first support surface and the second support surface may be arranged to bear forces in two substantially perpendicular directions corresponding to the vertical direction and the horizontal direction.

The lid component stacking step and/or the can stacking step may comprise one or more interruptions, such as two interruptions, three interruptions or four interruptions. The interruptions may be arranged as a pair of interruptions at opposing locations along the peripheral edge of the outer cover surface, for example at opposing side portions of the peripheral edge of the outer cover surface. The interruption may be arranged only in the top part of the cover part or also in the frame structure of the cover part.

When the lid component is applied to an intermediate tank in a production process for producing a composite tank as disclosed herein, the interruptions in one or both of the stacking steps may serve as a separation mechanism that facilitates gripping and separating individual lid components from the stack of lid components. Providing a separation mechanism is particularly useful when the stacked cover members fit snugly against each other, with a very thin separation line between the stacked cover members. Although such tightly fitting cover parts form a compact stack with a smooth and regular shape, which is beneficial for storage and transport of the stacked cover parts and for handling the stack of cover parts in a packaging machine, it has been found that the cover parts tend to stick together tightly and are difficult to separate at the high speeds required in the production process. In addition to facilitating separation of the tightly stacked lid components by inserting the clamping member into the interruption, the interruption also resists the formation of sub-atmospheric pressure in the space between the stacked lid components, as the interruption acts as an air passage between the interior of the stack and the exterior of the stack. The reduced air pressure in the interior space between the stacked cover members creates a suction force that tends to hold the cover members securely together. Conversely, pressure in the interior of the stack above the exterior thereof may tend to reduce the stability of the stack by forcing the lid members apart.

The stacking step may extend over a locking tab arranged at an edge of the lid, whereby the locking tab in the closed position forms a continuous part of the side wall portion of the lid portion. At the same time, the portion of the stacking step disposed on the locking tab may facilitate improved grippability of the locking tab and facilitate manipulation of the locking tab between the open and closed positions.

The concave gripping region may be disposed on an outer lid surface of the top portion of the lid portion. The recessed gripping area is disposed at the free end portion of the locking tab and serves to protect the free end portion of the locking tab from inadvertent opening while providing access to the free end portion of the locking tab. Thereby, even if no part of the locking flap in the closed position extends beyond the outer lid surface of the top part of the lid part in the height direction of the lid part, the locking flap can be easily manipulated.

As an alternative to continuous or discontinuous lugs or stacking steps arranged at the periphery of the outer lid surface, the stacking member at the can opening may be provided as two or more support surfaces cooperating with a corresponding stacking member at the bottom of the can. The stacking members at the bottom of the cans may be in the form of downwardly extending bottom edges as set forth above, or may be in the form of bumps or other protrusions that provide the desired spacing between the can bottom sealing member and the peripheral ledge or other support surface on which one or more stacking members at the bottom of the cans rest when stacked one on top of another.

The tubular body of a composite tank as disclosed herein may have four body wall portions; the front wall section is disposed opposite the rear wall section, and two opposite side wall sections extend between the front wall section and the rear wall section. The main body wall portions are connected by curved corner portions to provide a soft, slightly rounded appearance to the package can. Further, the shape of the body wall portions may deviate from a planar shape, with one or more of the body wall portions having an outward or inward curvature. When the tubular body has one or more outwardly curved body wall portions, the curvature of any such body wall portion is always less than the curvature of any curved corner portion, i.e. the radius of curvature of the corner portion in the tubular body of the composite tank as disclosed herein is always less than any radius of curvature of the body wall portion. The transition between the corner portion and the body wall portion may be considered a different change in curvature or may be considered a continuous change in curvature.

Alternatively, the tubular body may be manufactured without different body wall portions and may have any suitable covering shape, such as circular, oval or elliptical.

In composite cans, there is a conflict between minimizing the amount of paperboard material used in the can and making the can sufficiently rigid to avoid damage to the can or collapse of the can, for example, during production or when stacked for transport and storage. It has been found that by bending all can walls only slightly outwardly, the shape stability and rigidity of the composite can is greatly improved as compared to conventional packaging cans having planar walls. Thus, the radius of curvature of the top and bottom end edges of the tubular body controlling the curvature of the tank wall portion is preferably selected such that the tank wall portion is provided with a near-planar shape, thereby meaning that the tank wall portion can be perceived by the naked eye as being planar.

The paperboard-based composite cans as disclosed herein are used as protective shipping and storage cans at the retail end and as storage and dispensing cans at the consumer end. In addition to the openable and closable lid, the composite can is manufactured with a top sealing member attached inside the tubular body of the can at a distance from the top end edge of the tubular body. The top sealing member keeps the contents fresh and prevents contamination until the filled and sealed can is delivered to the consumer. Once the top sealing member has been broken or removed in order to access the contents of the can, the ability of the can to protect the contents from adverse effects from the environment depends primarily on the ability of the reclosable lid to form a tight closure at the access opening of the can. Composite cans for products such as infant formula, coffee, tea, cereals, etc. will typically contain more packaged products than will be used in each dispensing scenario. Thus, it is desirable that the product remaining in the can retain properties, such as flavor, aroma, spoonability (spoonability), vitamin content, color, etc., at least for a period of time corresponding to the time that a consumer is expected to spend using up all of the contents in the package can.

As set forth herein, by joining the top rim to the inner surface of the tubular body by means of welding, such as high frequency induction welding, it is possible to obtain an attachment having a sealing capability superior to that which is typically achievable with adhesive attachments. The welded top rim is preferably a plastic rim and connects the inner surface of the tubular body with the inner surface of the lid and helps to create a continuous barrier between the tubular body and the lid. The weld seal forms a first seal between the top rim and the inner surface of the tubular body, and the contact surfaces of the top rim and the lid form a second seal between the top rim and the lid. The first seal is a permanent seal that is always present and the second seal is an openable seal that is only effective when the lid is closed over the can access opening and the inner surface of the lid is pressed against the top rim.

The cover or the cover member may be applied using a cover attachment unit, which is a device for automatically applying the cover to the tundish. The cap attachment unit may include a rotatable unit including a cap holding member, a cap feeding unit, and a cap applying unit. The apparatus may further comprise an article application unit configured to apply a separate additional article into the tundish, into a holder arranged on the top rim or on the inner side of the lid. The additional item may be a spoon or other utensil, toy, brochure, etc. Alternatively, the article applicator may be provided as a separate device from the cover attachment unit.

After the application of the lid (e.g. in the form of a lid component), the assembled composite cans may be transferred in a conventional manner to further equipment in the packaging line, such as a cartoning machine, a palletizer, a weighing unit and a stacker. The packaging line usually ends with a stacker.

Definition of

The cardboard-based sheet material for forming the tubular body and the basic sealing member is mainly made of cellulose fibres or paper fibres forming a cardboard layer in a cardboard material. The paperboard layer may be a single layer or a multi-layer material. The sheet material is a laminate comprising, in addition to a paperboard layer, at least one thermoplastic polymer layer in the form of a film or coating, and a metal foil layer, preferably an aluminium layer. The metal foil layer is covered by at least one polymer layer and is arranged at the surface of the sheet-like material that will form the inner surface of the composite tank, i.e. at the surface that will face the interior of the composite tank. The polymer layer may also be arranged at the surface of the sheet material that will form the outer surface of the composite container. In addition to the inner and optional outer polymer layers of the polymer and metal foil, the sheet material may be coated, printed, embossed, etc. and may include fillers, pigments, binders, and other additives as known in the art.

The term "tubular body" should be understood to mean any hollow tubular shape assumed by the body blank during manufacture and filling of the composite can as disclosed herein, as well as the shape that the body has in the final assembled and filled composite can. Thus, a tubular shape as used herein may be a cylindrical shape or a shape having any other useful cross-section, such as a square, rectangular, or other polygonal cross-section or a modified polygonal cross-sectional shape having rounded corners. The tubular shape also includes any instantaneous shape that the tubular body can assume during the manufacturing process. By way of example, the cross-section of the tubular body may initially present a drop-shaped appearance with a distinct peak at the end-to-end junction between the edges of the body blank and a curved portion opposite the peak.

The term "tank component" as used herein refers to the tubular body of the composite tank, as well as any component intended to be attached to the tubular body so as to form an integral part of the composite tank as disclosed herein. Examples of tank components that may be part of a composite tank as disclosed herein are: a tubular body, a body sealing strip, a top sealing member, a bottom sealing member, a top rim, a reclosable lid and frame structure, a lid component, a bottom rim, a scoop holder, and a scoop. Only the tubular body, body seal strip, top sealing member, bottom sealing member, top rim and reclosable lid are integral components of the composite can as disclosed herein.

The top and bottom sealing members are sheet-like parts which are applied inside the tubular body of the composite tank such that they cover the cross-sectional area of the tubular body. The bottom sealing member forms a bottom end closure of the composite tank and the top sealing member forms an inner transfer seal of the composite tank. The top sealing member is typically attached at the access opening of the composite can at a distance from the edge of the opening that is at least sufficient to allow the top rim to be attached over the top sealing member, and may also allow a scoop or other added item to be contained in the space between the top sealing member and the inner surface of the reclosable lid.

The top and bottom sealing members may be made of paper, cardboard, plastic film, aluminum foil, and laminates of such materials. Typically, the bottom sealing member is made of a laminate comprising a paperboard substrate and an aluminium foil layer on the side that will face the interior of the composite can. The bottom sealing member is typically coated with an outer layer of thermoplastic polymer material. The top sealing member is typically a flexible component made of a laminate of one or more layers of aluminum foil and an outer layer of thermoplastic polymer material. However, cardboard-based top sealing members are also known in the art. The top sealing member is typically arranged to be partially or completely removed at the initial opening of the composite can and may be provided with an opening mechanism as known in the art, such as a tear strip, gripping tab or the like.

The top and bottom rims are typically made of a plastic material, such as a thermoformable plastic material, and take the form of a closed ring, the rims being applied to the inner surface of the tubular body of the composite can, with at least a portion of the rims being welded to the inner surface of the tubular body. The plastic rim provides the tubular body with increased rigidity at the end edges of the tubular body. Preferably, the plastic rim is sufficiently elastically deformable such that it can withstand lateral deformation without breaking or permanently deforming, for example, upon insertion into the tubular body or upon exposure to accidental impacts during use. The rim may also cover the end edge of the tubular body and may optionally extend onto the outer surface of the tubular body.

As referred to herein, an "intermediate can" is a can formed after bending a paperboard blank into a tubular shape and sealing the joined edges of the bent paperboard blank to form a tubular body. The treated tank remains the "tundish" until the last component has been applied to complete the composite tank. Generally, the composite can is fully assembled when the reclosable lid has been applied as the final component.

A composite tank as disclosed herein is a tank for dry or wet goods (commonly referred to as "discrete particles"). Such products are non-liquid, generally particulate materials that can be poured, scooped or removed from a can by hand. The can is typically a disposable can intended to be discarded after its contents have been emptied.

"particulate material" or "particulate article" should be broadly understood to include any material in the form of granules, abrasive grains, plant pieces, short fibers, flakes, seeds, bits, and the like. Particulate items suitable for packaging in composite cans as disclosed herein are typically flowable, non-liquid items, allowing a desired amount of the item to be poured, scooped or otherwise removed from the composite can by hand.

A composite can as disclosed herein may be a can for a food or consumable product such as infant formula, coffee, tea, rice, flour, sugar, rice, peas, soybeans, lentils, grains, soup, batter, pasta, snacks, and the like. Alternatively, the packaged article may be non-food, such as tobacco, detergent, dishwashing liquid, fertilizer, chemicals, and the like.

By openable or peelable top sealing member is meant a sealing member that can be removed, either completely or partially, by a user, in order to provide initial access to the internal compartment of the composite can by breaking the seal between the sealing member and the inner surface of the tubular body of the can, or by tearing or otherwise breaking the sealing member itself. The tearable sealing member may be provided with one or more predefined weakenings, such as perforations or cuts partially through the film, and may have a tear strip arranged therein to facilitate removal of the sealing member. The peelable top sealing member is typically provided with a gripping tab to assist in initiating separation from the inner surface of the tubular body and subsequent removal of the sealing member.

The top sealing member is preferably placed at a distance from the upper end edge of the tubular body of the composite tank, which allows the top rim to be attached to the inner surface of the tubular body between the top sealing member and the top end edge of the tubular body. Alternatively, the upwardly directed edge portion of the rupturable sealing membrane may extend into the welded junction between the top rim and the inner surface of the tubular body. The distance between the top sealing member and the top end edge of the tubular body may be about 10 to 60 mm. If the top sealing member is placed at a distance of 30 to 60 mm from the top end edge of the tubular body, the space above the top sealing member may be used to accommodate a scoop or other item provided in connection with the packaged product. Examples of other items that may be provided are flyers, coupons, and/or clips, forks, or other utensils.

The weld seal between the top rim and the inner surface of the tubular body is preferably a spill-proof seal, more preferably a moisture-proof seal and most preferably an air-tight seal. A canister having a volume of approximately 1 liter may be considered to be gas impermeable if it provides an oxygen barrier of approximately 0.006cc oxygen/24 hours or less at 23 ℃ and 50% relative humidity.

A higher tightness of the composite can and any seals between the elements of the can may be desirable when the packaged product is sensitive to moisture and/or sensitive to degradation under exposure to ambient air. It may also be desirable for the composite can to be aroma-tight in order to preserve the flavor and aroma in the packaged item and to prevent the packaged product from absorbing the flavor and aroma from the outside of the composite can. Thus, the composite tank may act as a barrier in both the inward and outward directions.

By subjecting the fill contents in the open intermediate tank to a protective atmosphere in conjunction with the filling step, the amount of air trapped inside the tank when the bottom closure is applied can be minimized. In addition, since a protective atmosphere is created between the arrival of the filled intermediate tank at the sealing station, the atmosphere in the sealing station and in the sealing step can be very well controlled, since no air needs to be removed from the filled open container before the container is sealed. This has been found to be a considerable advantage, since the pressure difference in the sealing step may adversely affect the sealing process by causing turbulence in the packaging material. This turbulence may cause powder material to become trapped in the seal and potentially compromise the tightness of the seal.

Drawings

The invention will be further illustrated by way of non-limiting example and with reference to the accompanying drawings, in which:

figure 1 shows a schematic view of an assembly line for producing and filling composite tanks;

figure 2a shows an exploded view of a composite tank as disclosed herein;

FIG. 2b shows a scoop and a stack of scoops;

FIG. 3 shows the assembled all-component composite tank of FIG. 2 a;

FIG. 4 shows a canister component applicator;

fig. 5 shows an attachment unit which may be part of the tank component applicator shown in fig. 4 in a first production stage;

fig. 6 shows the attachment unit of fig. 5 in a second production stage;

FIG. 7 shows a transfer plate with transfer chambers; and

fig. 8 shows a positioning device.

Detailed Description

Hereinafter, the present invention will be illustrated by examples. The examples are included to explain the principles of the invention and not to limit the scope of the invention as defined by the appended claims. Details from two or more embodiments may be combined with each other.

Fig. 1 shows an assembly line 1 that may be used for producing and filling composite tanks according to the method as disclosed herein. The assembly line 1 is configured for assembling composite tanks by forming tubular bodies and attaching tank components to the tubular bodies in the intermediate tank stream. Fig. 2a and 3 show an exemplary tank 101 that may be produced on the assembly line 1 of fig. 1. It should be understood that the particular shape of the tank 101 shown in fig. 3 should not be considered as limiting to the present invention, as the assembly line 1 is suitable for producing and filling tanks of any useful shape or size, and for producing composite tanks without such components, which are disclosed herein as optional.

The illustrated assembly line 1 comprises a plurality of machine units 3-10 connected by conveyor belts 2a, 2b, 2c, 2 d. Starting in sequence from the assembly line 1, the machine units are: a main body forming unit 3, a filling unit 4, a gas tank 5, a sealing unit 6, a cleaning unit 8, a can-inverting unit 9, a spoon inserting unit 10, and a lid attaching unit 7. A further conveyor belt 2e is arranged at the end of the assembly line 1 and is arranged to convey the produced composite cans from the lid attachment unit 7 and further, for example, to a packaging plant (not shown).

The production of composite tanks on the assembly line 1 is described below with reference to a single composite tank. It will be appreciated that, while running the assembly line 1, a plurality of composite tanks are produced in succession and exit the lid attachment unit 7 at the end of the assembly line 1. As set forth herein, the machine units of the assembly line 1, such as any tank component attachment unit, may be configured to process multiple intermediate tanks, such as 2, 3, 4, 5 or 6 intermediate tanks, simultaneously. Exemplary tank component attachment units 405, 406 are shown in fig. 5, 6 and 7.

The main body forming unit 3 includes: a body blank picking station 11, a body forming station 12, a top sealing station 13 and a top rim application station 14.

In the body blank picking station 11, body blanks 16 are picked from a stack of body blanks 16 and transported to the body forming station 12. In the body forming station 12, a tubular body is formed by bending a body blank 16 and merging two opposing edges of the body blank together into an end-to-end joint (also referred to as a "butt joint"). As shown in fig. 2a, the engagement portion extends between the top end and the bottom end of the tubular body in the height direction H of the tubular body. The joint is then sealed by means of a sealing strip welded to the inner surface of the tubular body, thereby forming an intermediate tank. The sealing strip and the inner surface of the tubular body constitute a weldable polymer layer on the abutting surfaces. As disclosed herein, the sealing strip is preferably welded to the inner surface of the tubular body by means of high frequency induction welding.

After the tubular body is formed and the sealing strip applied, the tundish is transported to a top sealing station 13 and the top opening at the top end of the tubular body is sealed by attaching a top sealing member across the top opening. The top sealing member is attached by welding a peripheral flange of the top sealing member to the inner surface of the tubular body. As disclosed herein, the top sealing member is typically a flexible component made from a laminate of one or more layers of aluminum foil and an outer layer of thermoplastic polymer material, and the peripheral flange is created by folding an edge portion of the top sealing member outwardly from the plane of the top sealing member and into alignment with the inner surface of the tubular body. The top sealing member is taken from a certain box, not visible in fig. 1, and applied at a distance from the edge of the top opening to allow the attachment of the top rim over the top sealing member. If the composite can includes a scoop, leaflet or other complementary item, the top sealing member may be applied at a sufficient distance from the edge of the top opening to allow the item to be contained in the space formed between the top sealing member and the inner surface of the reclosable lid.

The tundish with the applied top sealing member is then transported to a top rim application station 14 where the top rim is applied to the tundish by inserting at least a lower portion of the top rim into the top opening above the top sealing member. Preferably, the top rim is inserted into the tubular body such that the upper end edge of the top rim remains outside the tubular body or flush with the top end edge of the tubular body, whereby the top rim protects the fragile cardboard edge of the tubular body during subsequent process steps and forms a rigid resting surface for the tundish.

As shown in fig. 1, the body forming unit 3 is enclosed in an outer case 20. The can inversion arrangement may be further arranged inside the outer shell 20 so that the intermediate can with the top rim attached may be inverted directly after the rim is applied. Alternatively, the tundish is inverted in a conventional inverting apparatus disposed downstream of the top rim application station 14. An example of a conventional inverting apparatus is shown by a can inverting unit 9, which is located downstream of the body forming unit 2. The tank-inverting unit 9 operates by tipping the tundish on an inclined conveyor.

After applying the top rim and turning the tundish upside down, the tundish is transferred to the first conveyor 2a and placed with the top rim resting on the conveyor 2a, while the bottom opening at the bottom end of the tubular body faces upwards in the vertical direction. The intermediate tank is moved by the conveyor belt 2a to the filling unit 4 where it is filled with dry or wet goods through the bottom opening of the tubular body.

Subsequently, while still resting on the top rim, the filled tundish is moved by the second conveyor 2b to the gas box 5, where it is treated by the protective gas while moving it through the gas box 5. The gas box 5 is an optional part of the process equipment for carrying out the method as disclosed herein, which part may be used, for example, when the packaged item is sensitive to oxygen and/or moisture. Additionally, as set forth herein, creating a protective atmosphere for a filled tundish may be performed by other means. After leaving the gas box 5, the filled intermediate tank is transported on a third conveyor 2c to a sealing unit 6. The third conveyor belt 2c moves through a gas tunnel tightly fitted to the wall of the sealing unit 6 at the entrance into the sealing unit 6, in order to maintain the protective atmosphere created in the gas box 5.

In the sealing unit 6, the bottom opening of the tubular body is sealed in the can sealing station 21 by attaching a bottom sealing member across the bottom opening by welding a peripheral flange of the bottom sealing member to the inner surface of the tubular body at a distance from the bottom end edge of the tubular body. Thus, the bottom sealing member is applied in a corresponding manner to the top sealing member by folding the peripheral edge portion of the bottom sealing member into alignment with the inner wall of the tubular body, after which the facing surfaces of the bottom sealing member and the tubular body are welded to each other. The sealing unit 6 preferably comprises a rim application station 22 for applying the bottom rim after the bottom sealing member has been inserted into the tubular body and welded in place. As disclosed herein, the application of the bottom rim is an optional operation that may be performed on the tundish.

As can be seen in fig. 1, the sealing unit 6 is enclosed in an outer housing 23, similar to the outer housing 20 of the closure body forming unit 3. By sizing and shaping the inlet and outlet ports 24, 25 of the outer housing 23 according to the size and shape of the intermediate tank produced on the assembly line 1, the ports 24, 25 can remain substantially sealed by the intermediate tank passing continuously through the ports 24, 25 during production. Therefore, it is possible to maintain a protective atmosphere inside the outer casing 23 during the bottom sealing operation.

After filling, bottom sealing and optional application of the bottom rim, the tundish is turned over again so that the top rim is in a vertically upward facing position.

Similar to the first inversion operation performed after the top rim is applied, the tank inversion arrangement may be part of the sealing unit 6, so that the intermediate tank can be inverted directly after the bottom seal and optional bottom rim are applied. In the assembly line 1 shown in fig. 1, the tundish is turned over instead in a conventional turning unit 9 arranged downstream of the sealing unit 6.

In the example shown in fig. 1, the cleaning unit 8 is arranged between the sealing unit 6 and the reversing unit 9. In the cleaning unit 8, any product residues that may fall to the outside of the intermediate tank during the previous process step are removed by means of pressurized air. The cleaning unit 8 is optional for an assembly line as disclosed herein and may be particularly useful when the packaged item is a powder, or has small sized particles or particulate material containing debris that may cause dust.

As set forth herein, a scoop or other item may be placed over the top sealing member prior to final closure of the composite can by attachment of the lid. As shown in fig. 1, the spoon insertion unit 10 and/or other article insertion unit may be disposed downstream in the process line from where the composite can has been flipped to have its top end facing upward. In the assembly line shown in fig. 1, a spoon insertion unit 10 is disposed behind the flipping unit 9.

After that, the filled and sealed intermediate tank is conveyed on the conveyor 2d to the lid attachment unit 7, and the reclosable lid is attached at the top end of the tubular body so that the inner surface of the reclosable lid is in direct contact with the upper surface of the top rim. As set forth herein, the reclosable cap can be applied as part of a cap component that further includes a frame structure. Preferably, the cover member is mechanically attached to the upper rim by a snap-fit connection.

The assembly line may further comprise quality control equipment, and equipment for removing defective intermediate composite tanks and fully assembled composite tanks from the composite tank stream. Such quality control equipment may include detection equipment for detecting flaws in the tundish or machine faults during production, such as visual detection devices, X-ray machines which may be provided behind the cover attachment unit 7, and the like. In addition, the quality control equipment may include a can reject station, which is typically provided behind one or more of the body forming unit 3, the filling unit 4, the sealing unit 6, the scoop insertion unit 10 and the lid attachment unit 7 to ensure that any defective composite cans have been removed from the production line.

As disclosed herein, the composite tank is filled with dry or wet goods in the form of granules or bits, granules, flakes, grains, and the like. These items flow into the composite tank under the influence of gravity.

The composite tank 201 shown in fig. 2a and 3 may be produced on the assembly line 1 in fig. 1 and comprises a tubular body 203 having a tubular body wall 205. The main body wall 205 extends in the height direction H of the can 201 from a bottom end edge 207 at the bottom end of the tubular body 203 to a top end edge 209 at the top end of the tubular body 203. The tubular body 203 has a top opening 211 at a top end and a bottom opening 213 at a bottom end.

A bottom sealing member 215 is positioned at the bottom end of the tubular body 203 and covers the bottom opening 213. As set forth herein, the tubular body 203 has been formed by bringing the side edges of the body blank together end-to-end and sealing the joint with a sealing strip 214.

The bottom end edge 207 is reinforced by a reinforced bottom rim 217 applied to the inner surface of the body wall 205 and/or the peripheral flange 216 of the bottom sealing member 215 between the bottom sealing member 215 and the bottom end edge 207. In the embodiment shown, the bottom rim 217 has an outwardly directed flange 219 that covers the bottom end edge 207 of the tubular body 203 and forms the bottom edge of the tank 201. The bottom rim 217 reinforces the bottom end edge 207, stabilizing the shape of the tubular body 203 and protecting the bottom edge 207 from mechanical deformation. Bottom rim 217 also serves as a protective barrier against water and other fluids that may be present on the surface on which tank 201 is placed. The bottom rim 217 defines a downwardly open space between the bottom sealing member 215 and the bottom edge of the can 201, which may be used to accommodate a stacking element arranged at the upper end of another can when two or more cans are stacked on top of each other. Reinforced bottom rim 217 is an optional component of a composite tank as disclosed herein.

As an alternative to the bottom rim 217 shown, the bottom edge of the composite can 201 may be formed by a rolled edge of the tubular body 203, or may be provided by a simple non-rolled joint between the bottom sealing member 215 and the tubular body 203.

The composite tank 201 is provided with a closure arrangement comprising a lid 221 and a top rim 223 extending along the edge of the top opening 211. The lid 221 includes an in-plane sealing disk 225 that seals against the top rim 223 when the composite tank 201 is closed as shown in fig. 3. The tank 201 is further provided with a fully or partially removable top sealing member 227 which is sealed to the body wall 205 along the upwardly folded peripheral flange 218.

Bottom rim 217 and top rim 223 are made of a plastic material, preferably a thermoplastic material, and form a closed loop as shown in fig. 2 a.

Top rim 223 defines a perimeter of an access opening that is smaller than upper container body opening 211 as defined by upper end edge 209 of tubular body 203.

As set forth herein, top rim 223 is attached to the inner surface of body wall 205 at top opening 211. The top rim 223 has an extension in the height direction H of the composite tank 201 and has a lower rim portion facing the bottom sealing member 215 and an upper rim portion facing away from the bottom sealing member 215. The top rim 223 extends around the entire perimeter of the top opening 211. An upper portion of the top rim 223 protrudes upward above the top end edge 209 in the height direction H, whereby a portion of the top rim 223 is arranged above the top end edge 209 in the height direction H of the composite tank 201.

The top rim 223 is joined to the inner surface of the body wall 205 by means of a welded seal extending around the top opening 211. The weld seal preferably extends continuously around the top opening 211 and is a spill proof weld seal, but is also preferably a moisture proof weld seal, and most preferably a gas tight weld seal.

As set forth herein, the weld seal between top rim 223 and body wall 205 is formed by: energy is supplied to heat and locally soften or melt one or more thermoplastic components in top rim 223 and/or in a coating or film on the inner surface of body wall 205 and press top rim 223 and body wall 205 together in a direction perpendicular to body wall 205. The temperature and pressure can be controlled and adjusted to form a strong, tight seal without damaging the welded components. The thermoplastic material used to create the weld seal may be provided by a fully or partially thermoplastic top rim 223, a thermoplastic film or coating on the interior surface of body wall 205, or thermoplastic material in both the top rim 223 and body wall 205. Top rim 223 is preferably made of a thermoplastic material that allows it to be thermoformed, for example by injection molding. An injection molding process may be used to form plastic parts having different polymer compositions in different portions of the plastic part. For example, the surface of the plastic top or bottom rim to be welded to the container body may be formed of a polymer composition having a lower softening point and melting point than the rest of the rim. Furthermore, the abutment surface on top rim 223 may be formed from a resilient thermoplastic polymer. As set forth herein, any suitable welding technique may be used, such as ultrasonic welding or high frequency induction welding, with high frequency induction welding being preferred.

The cover 221 is a molded member having a three-dimensional shape that provides an upper outer surface of the cover 221. The cover may have an inner surface comprising a pattern of reinforcing ribs. The composite can shown in figure 2a comprises a planar sealing disk 225 applied to the inner surface of the lid 221. The sealing disc 225 is arranged to seal against the upper portion of the top rim 223 when the composite canister 201 is in the closed position as shown in fig. 3. Alternatively, the inner sealing surface of the cap may be integral with the cap. A further alternative for creating a sealed closure between top rim 223 and lid 221 is by arranging a sealing ring on the inner surface of lid 221, or by applying a sealing coating on selected portions of the inner surface of the lid and/or on top rim 223.

The cover 221 is connected to the frame structure 230 by a hinge 229, the cover 221 and the frame structure 230 together forming a cover part 231. The hinge 229 is a living hinge integrally formed with the cover 221 and the frame structure 230 as a flexible connection between the cover 221 and the frame structure 230. As set forth herein, the hinges shown serve only as non-limiting examples, and it should be understood that any other type of functional hinge may be used for the connection between the frame structure and the cover. Furthermore, the cover may be of a removable type without forming any permanent connection with the frame structure.

A frame structure 230 is applied to the composite tank 201 at the top end edge 209 and is mechanically attached to the top rim 223 by a snap-fit connection. Frame structure 230 is attached to top rim 223 after top rim 223 has been welded to the inner surface of body wall 205. The frame structure 230 is applied to the top rim 223 by: the frame structure 230 is pressed down onto the upper edge of the top rim 223 until the frame structure 230 locks in place on the top rim 223 by means of the top rim 223 and a mating snap-in feature on the frame structure 230. When the frame structure 230 has been attached to the top rim 223, it can only be removed again by breaking or damaging the snap-in connection between the top rim 223 and the frame structure 230.

The interior compartment 208 containing the packaged articles is defined by a top sealing member 227 at the upper end of the tubular body 203 and a bottom sealing member 215 at the bottom end of the tubular body 203.

To gain access to the packaged item in the interior compartment 208 for the first time, the user needs to open the cover 221 and expose the packaged item by removing the top sealing member 227, either completely or partially. The top sealing member 227 may be arranged to be peeled off the wall 205 of the tubular body 203, or a mechanism (means) for breaking the top sealing member 227 may be arranged such that it may be at least partially removed through the access opening. Such means may be in the form of one or more predefined weakenings, such as perforations or cuts partially through the top sealing member 227. When the top sealing member 227 is of the tear-open type, a narrow edge portion of the top sealing member 227 may be left at the inner surface of the body wall 205. Any such residual portion of top sealing member 227 preferably should not be so large that it extends into and restricts the access opening defined by the inner perimeter of top rim 223.

Once the top sealing member 227 has been removed, it is sufficient to open the lid 221 to access the packaged items in the interior compartment 208 through the access opening. As can be seen in fig. 2a (which discloses the interior of top rim 223), the area of the access opening is defined by the inner perimeter or inner contour of top rim 223. Since the top rim 223 is applied on the inner surface of the body wall 205 and adds thickness to the body wall in the inward direction, the area of the access opening is always smaller than the area of the top opening 211 of the tubular body 203.

When the composite can 201 is opened, a desired amount of packaged goods can be removed from the composite can 201 via the access opening by means of a spoon or by pouring. The scoop may preferably be provided with the composite can 201. The scoop may be initially placed on top sealing member 227, may be removably attached to the inner surface of lid 221, which in the example shown in fig. 2a is constituted by sealing disc 225. When placed on top sealing member 227, the scoop may be packaged in a protective wrap, such as a paper or plastic bag. Another alternative is to attach the scoop to top rim 223, for example by placing the scoop head in a scoop holder 240 provided on top rim 223 as shown in fig. 2 a. In the illustrated embodiment, scoop holder 240 also serves as a scraper bar for trowelling the scooped excess material from the scoop. In fig. 2b, an example of a scoop 280 is shown, the scoop 280 having a scoop head 281 and a scoop handle 282. Generally, the scoops 280 inserted into the intermediate tank are arranged in a stack during the manufacture of the composite tank as disclosed herein, for example, the scoop heads 281 are nested inside each other as shown in fig. 2 b. To facilitate stacking of the scoop 280 with the planar handle 282, the proximal end of the handle 282 may be provided with a stacking stabilization arrangement 284. The stacking stabilizing arrangement 284 allows the same scoops 280 to be stacked inside each other and helps to hold the stack 283 of scoops together, thereby simplifying storage and handling of the scoops 280 and loading of the scoops into the scoop insertion unit 10 as shown in fig. 1.

Advantageously, the scoop head 281 has a tapered shape to allow the scoops 280 to fit snugly inside each other in an efficient and space-saving manner.

As an alternative to stacking the ladle 280 by arranging the ladle head 281 and the ladle handle 282 in the same direction, the ladle 280 may be stacked in alternate opposite directions as known in the art.

It should be understood that the ladle 280 shown in fig. 2b constitutes only one example of a suitable ladle configuration and that ladles having differently shaped ladle heads, differently shaped handles, having different proportions between the ladle head and the ladle handle, etc. may be used in a composite ladle as disclosed herein. The ladle may further be provided with provisions for additional stacking stability and/or for enhancing the retention of the ladle 280 in the ladle holder. For example, the ladle head may comprise a thin snap-in ridge for releasably locking the ladle head in a desired position in the ladle holder. Such additional fastening elements for the ladle head may prevent the ladle head from inadvertently falling out of the ladle holder and may also serve to prevent the ladle handle from sagging into the composite ladle.

The top rim 223, as shown on the composite tank 201 in fig. 1 and 2a, is attached directly to the inner surface of the body wall 205, and the closing arrangement of the lid component 230, including the lid 221 and the frame structure 230, provides a tight closure between the lid 221 and the tubular body 203. When the lid 221 is closed on the composite tank 201, the upper edge of the top rim 223 abuts against the sealing disc 225 and a seal is created between the top rim 223 and the lid 221.

In order to keep the lid 221 fixed in the closed position between dispensing scenarios, as can be seen in fig. 2a and 3, the closing arrangement of the composite tank 201 may further comprise a locking arrangement 245. The locking arrangement 245 may comprise first and second cooperating locking elements, for example a female locking element, such as a groove arranged on the cover 221, and a male locking element, such as a rib arranged on a locking member 246 arranged on the frame structure 230. The locking member 246 is hingedly connected to the frame structure 230, such as by means of a living hinge 249 that is integrally formed with the frame structure 230 and the locking member 246.

This type of locking arrangement 245 is closed by moving the locking member 246 upwardly and inwardly on the cover 221 to a position where the locking elements are brought into mating engagement. The locking arrangement 245 is opened by pulling the locking member 246 until the connection between the locking elements is released and turning the locking member 246 downwards at the hinge 249. When the locking member 246 is in the closed position, in which the first and second locking elements engage each other, the cover 221 and the frame structure 230 are clamped together firmly, whereby the top rim 223 seals tightly against the sealing disc 225 on the inner surface of the cover 221, or against a sealing ring or sealing surface arranged inside the cover 221.

As best shown in fig. 3, the cover member 231 is provided with a cover member stacking step 251 and a can stacking step 252. As shown, the stacking

steps

251, 252 may extend through the locking member 246.

The cover member stacking step 251 is arranged such that the cover members 231 can be stacked on each other into a stack, which can be loaded into the cover attachment unit. The tank stacking step 252 is arranged for enabling the composite tanks 201 to be stacked on each other.

The recessed gripping area 265 may be disposed at a free end portion of the locking member 246 in the cover 221 opposite the hinge 249. Thus, the locking member 246 is easily accessible and the locking member 246 is protected from accidental release when in the closed position.

The composite tank 201 as shown in fig. 2a and 3 may be produced and filled on an assembly line such as that shown in fig. 1.

As set forth herein, a composite tank as disclosed herein is produced in the following order: forming a tubular body; applying a top sealing member and a top rim to the tubular body; turning the tubular body upside down; filling the tubular body with a dry or wet substance through the bottom opening of the tubular body; closing the bottom opening of the tubular body; optionally applying a bottom rim to the tubular body; turning the sealing can over so that the top sealing member again faces upwards; and finally applying a cap or cover member to the top end of the tubular body.

Fig. 4 to 7 show equipment that may be used to apply can components in the top sealing station 13, top rim application station 14, sealing unit 6 and bottom rim application station 22 of the assembly line 1 shown in fig. 1.

Referring to fig. 2a and 3, bottom seal member 215, bottom rim 217, top rim 223 and top seal member 227 are examples of tank components that may use the arrangement of fig. 4-7.

Referring to fig. 4, there is shown a canister sealing unit 401 which may be the sealing unit 6 of fig. 1.

The intermediate tank 403 is conveyed through the tank sealing unit 401 in the direction of travel R. The conveying mechanism 402 comprises a feed arrangement 411 in the form of two feed screw members arranged at respective opposite sides of the intermediate tank 403, only one of the feed screw members being visible in fig. 4; a main conveyor belt member 413; a movable clamping arrangement 415; and an exit conveyor member 419. An outlet conveyor member 419 is arranged downstream of the can sealing unit 401 and a stationary slide 421 is arranged at the outlet of the can sealing unit 401 downstream of the outlet conveyor member 419. Further details of useful delivery arrangements are described in WO 2013/009226 a1, to which reference is made.

The can sealing station 405 'is located downstream of the feeding arrangement 411 and the bottom rim application station 405 "is located downstream of the can sealing station 405'. Movable clamping arrangement 415 moves intermediate tank 403 to sealing station 405' where bottom sealing member 427 is attached by welding to the interior of the tubular body wall of intermediate tank 403 as shown in fig. 8. Tundish 403 then moves to bottom rim application station 405 "where, for example, bottom rim 417 is applied as shown in fig. 5 and 6. As shown in fig. 4-6, a plurality of bottom sealing members and bottom rim 417 may be attached to a plurality of corresponding intermediate tanks 403 simultaneously in order to increase the operating speed of tank sealing station 401. In the embodiment shown, four bottom sealing members and four rims are attached to respective tundish 403 at the same time. Alternatively, the bottom sealing member, rim, or other tank component as disclosed herein may be attached simultaneously in any other number (e.g., two, three, six, eight, or ten) of combinations other than four, or may be attached sequentially to the tank.

The transport mechanism 402 and the can sealing station 401 may be enclosed in an outer housing 20, 23 as shown in fig. 1. The outer housings 20, 23 are adapted to protect the tank sealing station 401 and/or to provide and maintain a protective atmosphere inside the tank sealing station 401. The protective gas may for example be nitrogen, carbon dioxide or a mixture of nitrogen and carbon dioxide.

The degassing of the intermediate tank may be performed simultaneously with the filling of the intermediate tank in the filling unit 4 as shown in fig. 1. Degassing may include supplying a protective gas to the flow of material to be contained in the tank during filling. Before the material reaches the tank, a protective gas may be blown into the material flow. If the material is treated with protective gas during filling, the intermediate tank 403 is preferably conveyed to a tank component applicator, such as a tank sealing station 401 arranged downstream of the filling unit 4, while maintaining a modified atmosphere, for example by moving the tank through a tunnel filled with protective gas (as shown by the covered conveyor belt 2c between the gas box 5 and the sealing unit 6 in fig. 1). Alternatively, the filled intermediate tank 403 may be introduced into a vacuum chamber to evacuate air, followed by subjecting the tank to a modified atmosphere and applying a bottom sealing member.

Fig. 5 and 6 show an attachment unit 505 for attaching a tank component, such as a bottom rim 517, to a tundish 503. The attachment unit 505 comprises a holding device 523, a support device 525, a positioning device 528 and a transport plate 529.

An example of a transmission plate 529 is shown in fig. 7. The transmission plate 529 extends in the following direction: a first direction x parallel to the running direction R of the tank component applicator of which the attachment unit 505 forms a part; and a second direction y perpendicular to the first direction x. The transfer plate 529 includes a cavity portion 531 having at least one transfer cavity 533 therethrough adapted to receive and hold a canister component, in this case the bottom rim 517, during transfer of the canister component into alignment with the end of the intermediate canister 503. The transmission chamber 533 has a first opening area A₁And is sized and configured such that the canister component may fit into the transfer cavity 533 and be retained therein during transfer to the intermediate canister 503.

Alternatively, especially when the tank component is a sheet-like tank component, such as a top sealing member or a bottom sealing member, the transmission plate 529 may be omitted such that the tank component is placed directly on top of the holding device 523.

In order to fit and hold the canister component in the transfer cavity 533, the transfer cavity 533 is shaped to correspond to the shape of the canister component.

In case the can part comprises an edge portion to be folded to create a peripheral flange before or during insertion of the can part into the can, just as in the case of the bottom or top sealing member, the first opening area a of the transfer chamber 533₁May be smaller than the surface area of the can part before folding. The area difference corresponds to the area of the portion of the can component forming the peripheral flange. Such folded flanges are typically strip-shaped and may have a width in the range of 1 to 10mm, such as in the range of 2 to 5 mm. See fig. 8. Thus, a sheet can component, such as a folded peripheral flange on a top or bottom sealing member, may be produced by: the canister component is pressed down through the transfer chamber 533, which has a smaller cross-sectional area than the canister component, forcing the canister component to fold at the edge of the transfer chamber to be received in the first opening area a of the transfer chamber₁And (4) the following steps.

The walls of the transfer cavity 533 may include a retaining element 534 adapted to retain the canister component in the transfer cavity 533. See fig. 7. Such a holding element 534 for the first open area a not covering the transmission cavity 533₁Is particularly useful, such as a top rim or a bottom rim. When the tank member is a sheet-like tank member, the holding member 534 may be omitted.

In the embodiment shown in fig. 7, there are four retaining elements 534 that are each adapted to retain a corresponding side of an annular canister component having a generally rectangular or square shape. In the embodiment shown, the retaining elements 534 are arranged such that they retain the tank component at the centre of each side. It would be feasible to use one, two, three, four or more such retaining elements 534. The retention element 534 may be resiliently compressible, for example, due to material properties or spring bias. Alternatively or additionally, the tank part itself, such as the rim, may be elastically deformable, for example due to material properties. The retaining element 534 may be used to compensate for tolerances with respect to the dimensions of the canister component and/or the transfer cavity 533. Additionally, the retaining element 534 may be used to temporarily press one or more sides of the tank component inwardly, thereby causing the tank component to assume a reduced cross-section, whereby the tank component will be more easily inserted into the intermediate tank 503. Thereby, the risk of the fragile cardboard edge of the tubular body of the intermediate tank 503 being damaged during insertion of the rim type tank part may be eliminated or at least significantly reduced.

As shown in fig. 5, 6, and 7, transmission plate 529 may include a cover portion 535 that is at least as large or substantially as large as the first open area of transmission cavity 533. As seen in the second direction y, the cover portion 535 is arranged adjacent to the cavity portion 531. Cover portion 535 has a minimum extension y in second direction y₁Said minimum extension being the area A of the transmission cavity 533₁Maximum extension y in the second direction y₂At least 1.0 times, preferably at least 1.2 times, more preferably at least 1.4 times. The use of a transfer plate with a lid portion 535 facilitates the placement and transport of the canister components into and out of the transfer chamber 533The alignment of the intermediate tank 503 prevents excessive escape of protective gas from the interior of the tank component applicator. When the tank component is instead a sheet component, it may be picked up by the suction member and placed in alignment with the opening in the intermediate tank 503 into which the sheet tank component is to be inserted. As set forth herein, the transmission plate 529 may be omitted and the sheet can component may be placed directly on top of the holding device 523. After application in the intermediate tank 503, the sheet-like tank part covers the tank opening and prevents gas from escaping through the intermediate tank 503. Transport plates without a lid portion may be used in applying the tank components if the tank component applicator is operated without a protective atmosphere or if some loss of protective gas can be tolerated. In addition, as indicated by the chain line in fig. 5 and 6, the attachment unit 505 may include an inner case 547. The inner housing 547 is located inside the outer housing 20, 23 as shown in fig. 1 and is arranged to provide enhanced protection against the escape of protective gas from the space above the positioning chamber 537 of the holding means 523.

To facilitate placement of the canister components into the transfer cavities 533 of the transfer plate 529, a recess 536 may be provided as shown in fig. 7. The recess 536 leaves room for gripping

members

544a, 544b, 544c, 544d arranged to move the canister component from the cartridge 543 into the transfer chamber 533. See fig. 5 and 6. If the retaining elements 534 are provided in the transmission plate 529, the notches 536 are preferably positioned so that they do not interfere with the retaining elements 534. Accordingly, the notch 536 may be located in a corner of the transmission cavity 533.

Such clamping members

544a, 544b, 544c, 544d and their corresponding recesses 536 are particularly useful when the canister component forms a ring that includes an interior volume, such as a bottom rim or top rim, that is filled with a gas, e.g., air.

If the canister component is a sealing member or cover, the canister component may alternatively be placed into the transport chamber 533 by a clamping mechanism, such as one or more suction cups. In this case, the notch 536 may be omitted. However, suction cups are not suitable when the canister components are of the ring type, such as a top rim or a bottom rim.

In the embodiment shown, which may for example be the bottom edge application station 22 of the assembly line 1 as shown in fig. 1, there are four cavity parts 531 in a row as seen in the first direction x. Each cavity portion 531 includes a respective transmission cavity 533 and is arranged with a corresponding respective cover portion 535.

Holding means 523 holds tundish 503 while a tank member (shown as bottom rim 517) is attached to tundish 503. The holding means 523 comprises at least one positioning chamber 537 therethrough having a first open area a with the transfer chamber 533₁Corresponding second opening area A₂. The positioning chamber 537 is adapted to receive a portion of the intermediate canister 503. If a cover part 535 is present, the size and shape of the cover part 535 of the transmission plate 529 is selected such that the cover part 535 can cover or at least substantially cover the second open area A of the positioning chamber 537₂。

The support means 525 is arranged to support the intermediate tank 503 and to position the intermediate tank 503 in the holding means 523.

As shown in fig. 5 and 6, the positioning device 528 is arranged to position the tank component in the intermediate tank 503. Thus, the positioning means 528 is aligned with the positioning chamber 537, as seen in the vertical direction z. The positioning device 528 is vertically adjustable, allowing insertion of tank components into the intermediate tank 503 up to a desired pre-selectable attachment position. As described herein with reference to fig. 8, the positioning means 528 may be expanded in a radial direction of the positioning chamber 537 and press the vertically extending portion of the tank part in a direction towards the wall of the positioning chamber 537, whereby the tank part is pressed against the inside of the tubular wall of the intermediate tank 503 placed in the positioning chamber 537.

In the embodiment shown, the attachment unit 505 is arranged to handle four intermediate tanks 503 simultaneously. As seen in the first direction x of the attachment unit 505, the transmission plate 529 comprises four cavity portions 531 arranged in a row. In a corresponding manner, the holding means 523 comprises four positioning chambers 537, and the supporting means 525 is adapted to support four intermediate tanks 503 and position the intermediate tanks 503 in the respective positioning chambers 537 of the holding means 523. Furthermore, the attachment unit 505 comprises four positioning means 528, which are aligned with the positioning cavities 537 such that each positioning means 528 is associated with a respective positioning cavity 537. It should be understood that the attachment unit may be arranged for handling any suitable number of intermediate tanks simultaneously, as set out herein.

The transmission plate 529 is movable between a first position shown in fig. 5 and a second position shown in fig. 6. In the first position, the transfer plate 529 has been moved in the y-direction such that the transfer cavity 533 has been moved away from the holding means 523. In this position, the transfer plate 529 is arranged to receive a canister component in the transfer cavity 533. If the transfer plate 529 is provided with a cover portion 535 as shown in fig. 5 to 7, the cover portion 535 covers or substantially covers the second opening area a of the positioning chamber 537 in the first position during application of the canister component in the transfer chamber 533 as shown in fig. 5₂. Thus, loss of protective gas through the positioning chamber 537 may be minimized or preferably eliminated.

In the second position, as shown in fig. 6, the transfer plate 529 has been moved in the y-direction, whereby the transfer chamber 533 has been brought into alignment with the positioning chamber 537 of the holding means 523 and the positioning means 528 arranged above the positioning chamber 537. When the transfer plate 529 is in the second position, the positioning device 528 may push the canister components located in the transfer cavity into the intermediate canister. A canister member, such as the bottom rim 517 shown in fig. 5 and 6, is pushed from the transfer cavity 533 in the transfer plate 529 into the intermediate canister 503 by moving the canister member downward in the z-direction through the transfer cavity 533 and at least partially through the positioning cavity 537 of the holding means 523.

The holding device 523 may include a welding unit 539 as disclosed herein. The welding unit is preferably a high frequency induction welding unit and is arranged around the positioning chamber 537. The welding unit 539 is adapted to weld the tank component to the intermediate tank 503 and comprises a coil extending around the positioning chamber 537. As explained herein, the tank component may be pressed against the welding unit 539 as the positioning device 528 may be expanded in a radial direction of the positioning cavity 537.

As shown in fig. 5 and 6, a bottom rim 517 or other can component can be placed in the transfer cavity 533 of the transfer plate 529 by means of an optional can component supply 541 comprising at least one clamping unit 542. A stack of canister components (e.g., bottom rim 517) may be stored in cassette 543. The number of stacks in the cassette 543 and the number of the chucking units 542 correspond to the number of the transfer cavities 533 in the transfer plate 529. The gripping unit 542 is capable of gripping a single canister part, here the bottom rim 517, moving it from the opening 545 in the cartridge 543 and placing it in the corresponding transfer cavity 533. As an example, four individual tank components are clamped simultaneously. The clamping unit 542 comprises four

clamping members

544a, 544b, 544c, 544d which clamp the corners of the bottom rim 517. The positions of the

clamping members

544a, 544b, 544c, 544d correspond to the positions of the notches 536 of the transmission plate 529. As set forth herein, such gripping

members

544a, 544b, 544c, 544d and their corresponding recesses 536 are particularly useful when the canister component is not a sheet-like element, such as a bottom seal member, an inner seal member, or a top seal member, but instead forms a ring, such as a top rim or bottom rim.

Fig. 8 shows a positioning device 828 as disclosed herein. The positioning device 828 may be used as the positioning device 528 of the attachment unit 505 as shown in fig. 5 and 6, or may be used to position the tank part in any attachment unit used to attach the tank part inside the tubular tank body. Thus, the positioning device may be used to place the tank component in the tubular body with or without the use of a transfer plate.

Fig. 8 shows top sealing member 827 in the process of being placed in tundish 803. As can be taken from fig. 8, top seal member 827 has a cross-sectional area that is greater than the internal cross-sectional area of tundish 803. When placed in the tundish 803, the edge portion 833 of the top sealing member 827 will fold upwards so that it conforms to the inner surface of the can wall 805. The illustrated top sealing member 827 is a foldable member such as a laminate of plastic film and aluminum foil, plastic film, paper sheet, paper/plastic laminate, or the like. The tank part, such as the top and bottom sealing members, may alternatively be pre-formed with a sealable rim portion extending perpendicular to the main plane of the tank part. In this case, folding of the edge portion is not required when inserting the can component into the tubular can body.

The positioning device 828 includes a substrate 849 comprising or consisting of a rigid material, such as a metal or composite material, and a piston skirt 851 comprising a resiliently deformable material, such as rubber or plastic. The piston skirt 851 is located on top of the base plate 849 such that it at least partially covers the upper surface of the base plate 849, which is opposite the lower cover surface 853 of the base plate 849.

During application of the tank component in tundish 803, cover surface 853 is configured to face the tank component, here top sealing member 827. The cover surface 853 of the base plate 849 has a circumferential edge 855, which in the example shown has a generally polygonal shape. However, it should be understood that the cover surface may have any other suitable shape that is suitable for the cross-sectional shape of the composite tank being produced. In the example shown, the substantially polygonal shape is a substantially square shape comprising four side edge portions connected by outwardly rounded corner portions. In the embodiment shown, each side edge portion is slightly curved inwardly. Thus, the circumferential edge 855 of the covering surface 853 of the substrate 849 having inwardly curved side edge portions deviates from the cross-sectional shape or covering area of the composite can produced. Alternatively, the substrate of the positioning device may have the same footprint as the tundish 803, with straight side edge portions between the curved corner portions.

It may be advantageous to arrange the curved side edge portion at least on the side of the base plate 849 that will face the sealing strip 814 covering the joint in the tubular body 805 during insertion of the tank part. The sealing strip 814 locally thickens the tubular wall 805 of the tundish 803 and also constitutes a bending line where the tubular wall 805 tends to bend, thereby deviating the tubular wall 805 from a desired planar or near-planar shape. The slightly inward curved side edge portions of the peripheral edge of the cover surface of the substrate allow the substrate to move along the joint when positioning device 828 inserts tank component 827 into tundish 803 without damaging the seal or tank body material.

The piston skirt 851 is transitionable between a non-expanded state and an expanded state by relative movement with respect to the base plate 849.

In the non-expanded state of the piston skirt 851, the shape of the outer contour of the piston skirt 851 corresponds to the shape of the base plate 849. Thus, in the non-expanded state, the piston skirt 851 has the same or substantially the same footprint as the base plate 849.

When viewed relative to base plate 849, outer peripheral portion 861 of piston skirt 851 is located at or above a circumferential edge 855 of base plate 849. Preferably, when piston skirt 851 is in the unexpanded state, peripheral portion 861 of piston skirt 851 is coincident with, or slightly inboard of, peripheral edge 855 of mantle surface 853 of base plate 849.

In the expanded state of the piston skirt 851, a covered area defined by an outer peripheral portion 861 of the piston skirt 851 is larger than that of the piston skirt 851 in the non-expanded state.

During the transition to the expanded state, pressure is applied to the piston skirt 851 from above. Thereby, the side edge portions of the piston skirt 851 are stretched between the corners and any curved side edge portions are thereby straightened out. By selecting the shape and material properties of the piston skirt 851, the desired shape change during the transition may be obtained.

In the expanded state of piston skirt 851, outer peripheral portion 861 of piston skirt 851 is at least partially outside of corresponding circumferential edge 855 of base plate 849. By transitioning the piston skirt 851 to an expanded state, the piston skirt can be brought into contact with the edge portion 833 of the top seal member 827 and caused to press the edge portion 833 of the top seal member 827 against the inside of the body wall 805.

If the tank component attachment unit is provided with a transmission plate 529 comprising a retaining element 534 exerting an inwardly directed force on the tank component as disclosed herein, the piston skirt 851 may help to press the tank component back in a radial direction in case the tank component itself cannot sufficiently spring back from a deformed configuration exerted on the tank component by the retaining element 534.

The positioning unit shown in fig. 8 comprises a first piston 871 and a second piston 873 coaxial with the first piston 871. Referring to fig. 5 and 6, the

pistons

871, 873 extend in an axial direction a coinciding with the vertical direction z of the attachment unit 505. A base plate 849 is attached to an end portion of the first piston 871 such that the cover surface 853 is perpendicular to the axial direction a. A piston skirt 851 is attached to an end portion of the second piston 873. The first piston 871 and the second piston 873 are configured to move together as a single unit and independently of each other in the axial direction a as separate elements.

During the displacement of positioning device 828 into tundish 803, piston skirt 851 remains in a non-expanded state until can component 827 moves to an attached position. When the canister member 827 has reached the attachment position, the piston skirt 851 is transitioned to the expanded state by moving the end portion of the second piston 873 closer to the end portion of the first piston 871, thereby pressing the edge portion of the piston skirt 851 radially outward.

The peripheral portion 861 of piston skirt 851 presses the canister member 827 against the inside of body wall 805 of tundish 803 located in the positioning chamber. An edge portion of the outer peripheral portion of the piston skirt 851, which is arranged to contact and apply pressure to the can part in the expanded state of the piston skirt 851, may have a contact surface that is slightly inclined with respect to the vertical direction of the positioning device in the non-expanded state of the piston skirt.

In order to further improve the contact between the tank part and the tank body material in the corner portion, a thickened corner portion may be arranged on the upper surface of the base plate, i.e. on the surface opposite to the mantle surface of the base plate. The thickened corner portions form raised areas on the upper surface of the base plate and serve to force the piston skirt further outwardly, thereby exerting increased pressure on the applied can component and improving contact between the can component and the tubular body. Thereby, the joint formed between the tank member and the corner portion of the tubular tank body can be improved. In particular, increased pressure in the corner portions of the tubular body may help create a tight seal between the body material and the sheet can component. When folding and aligning the can component with the tubular body wall, excess material present at the corner portions of the sheet-form can component, such as the bottom or top sealing members, can often wrinkle at the corners of the can. In this case, the increased pressure generated at the corner portions of the tubular body will compress the corrugations and will help form a good functional bond, such as a thermal weld between the body material and the sheet material in the can component. When a thermal welding process is used to bond the tank component to the wall of the tubular tank body, at least one of, and preferably both, the tank component and the tubular wall comprise a sufficient amount of thermoplastic material to create a functional bond.

Claims

1. A method for manufacturing a composite tank (201) and filling dry or wet goods in the composite tank (201), the method comprising:

-picking body blanks (16) from a stack of body blanks (16) and transferring the body blanks (16) to a body forming station (12);

-forming a tubular body (203) by bending the body blank (16) and merging two opposite edges of the body blank (16) together into an end-to-end joint, the joint extending in the height direction of the tubular body (203);

-sealing the joint by overlaying the joint weld bead (214) on the inner surface of the tubular body (203) forming an intermediate tank (403; 503);

the method is characterized by the following further steps:

-transferring the intermediate tank (403; 503) to a top sealing station (13);

-sealing a top opening (211) at a top end of the tubular body (203) by welding a peripheral flange (218) of a top sealing member (227) to the inner surface of the tubular body (203) at a distance from a top end edge (209) of the tubular body (203);

-transferring the intermediate tank (403; 503) to a conveyor belt (2a) and placing the intermediate tank (403; 503) on the conveyor belt (2a), the bottom opening (213) at the bottom end of the tubular body (203) facing upwards in a vertical direction;

-transferring the intermediate tank (403; 503) to a filling unit (4);

-filling the intermediate tank (403; 503) with the dry or wet product through the bottom opening (213) of the tubular body (203);

-subjecting the intermediate tank to a protective atmosphere during the filling thereof, or by introducing the filled intermediate tank into a vacuum chamber to evacuate air;

-transferring the filled intermediate tank (403; 503) to a sealing unit (6), to which the filled intermediate tank is transferred in a closed transfer system, while maintaining the protective atmosphere;

-sealing the bottom opening (213) of the tubular body (203) by welding a peripheral flange (216) of a bottom sealing member (215) to the inner surface of the tubular body (203) at a distance from a bottom end edge (207) of the tubular body (203), the sealing of the bottom opening (213) being carried out while maintaining the protective atmosphere;

-turning over the filled and bottom-sealed intermediate tank (403; 503) so that the top rim (223) is in an upward facing position in the vertical direction and transferring the intermediate tank (403; 503) to a lid attachment unit (7);

-attaching a reclosable cap (221) at the top end of the tubular body (203), wherein an inner surface of the reclosable cap (221) is in direct contact with an upper surface of the top rim.

2. The method according to claim 1, wherein the following steps are performed after sealing the top opening (211):

-transferring the tundish (403; 503) to a top rim application station (14);

-applying a top rim (223) to the intermediate tank (403; 503) by inserting at least a lower portion of the top rim (223) into the top opening (211) above the top sealing member (227);

-welding the inserted portion of the top rim (223) to the inner surface of the tubular body (203);

-transferring the intermediate tank (403; 503) to the conveyor belt (2a) and placing the intermediate tank (403; 503) on the conveyor belt (2a) such that the top rim (223) rests on the conveyor belt (2a) and the bottom opening (213) at the bottom end of the tubular body (203) faces upwards in a vertical direction.

3. The method according to claim 1 or 2, wherein closely fitting intake and exit tunnels are arranged at the inlet (24) and outlet (25) of the sealing unit (6).

4. The method according to any of the preceding claims, wherein the method comprises supplying a protective gas, such as nitrogen, carbon dioxide or a mixture of nitrogen and carbon dioxide, to the dry or wet goods during filling of the intermediate tank (403; 503) and/or after filling of the intermediate tank (403; 503).

5. The method according to any one of the preceding claims, wherein the sealing unit (6) is arranged in an outer housing (23) and is arranged to operate in a protective atmosphere in the outer housing (23).

6. The method according to claim 5, wherein an outlet port of the intermediate tank is arranged in the outer housing (23) of the sealing unit (6), wherein the size of the outlet port is adapted to the size of the intermediate tank being processed.

7. A method according to claim 6, wherein the outlet port comprises a short tunnel arranged at the end of the outlet conveyor belt member, wherein a fixed slide constitutes a floor in the tunnel.

8. The method according to claim 6 or 7, wherein an inlet port of the intermediate tank is arranged in the outer housing (23) of the sealing unit (6) and a closable hatch is arranged at the inlet port.

9. The method according to any one of the preceding claims, wherein the method further comprises:

-applying a bottom rim (217) to the bottom end of the bottom sealed intermediate tank (403; 503);

-during said transfer of the intermediate tank (403; 503) to the lid attachment unit (7), placing the bottom-sealed intermediate tank (403; 503) on a conveyor belt (2d), the bottom rim (217) resting on the conveyor belt (2 d).

10. The method according to any of the preceding claims, wherein prior to attaching the reclosable lid (221) at the top end of the tubular body (203), a scoop is applied between the top sealing member (227) and the reclosable lid (221), the scoop being applied directly on the top sealing member (227) or placed in a scoop holder (240) arranged above the top sealing member (227).

11. The method according to any of the preceding claims, wherein two or more intermediate tanks (403; 503) are treated simultaneously during one or more of the following:

-sealing the top opening (211);

-applying the top rim (223);

-welding the top rim (223);

-filling the intermediate tank (403; 503);

-sealing the bottom opening (213); and

-attaching the reclosable cap (221).

12. An assembly line (1) for manufacturing composite tanks (201) according to the method of any one of claims 1 to 11 and filling dry or wet articles in the composite tanks (201), the assembly line (1) comprising a plurality of machine units connected by conveyor belts (2a, 2b, 2c, 2d), characterized in that the machine units comprise:

-a body forming unit (3);

-a filling unit (4);

-a sealing unit (6); and

-a lid attachment unit (7).

13. The assembly line (1) according to claim 12, wherein a gas box (5) is arranged between the filling unit (4) and the sealing unit (6).

14. Assembly line (1) according to any one of claims 12 or 13, wherein the sealing unit (6) comprises a can sealing station (21) and a rim application station (22).

15. Assembly line (1) according to any one of claims 12 to 14, wherein the sealing unit (6) is arranged in an outer housing (23) and is arranged to operate in a protective atmosphere in the outer housing (23).