EP2421694A1

EP2421694A1 - Method of fabricating shopper bags and associated automated fabrication line

Info

Publication number: EP2421694A1
Application number: EP09802227A
Authority: EP
Inventors: Ruggero Peroni
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-30
Filing date: 2009-11-30
Publication date: 2012-02-29
Anticipated expiration: 2029-11-30
Also published as: CN102712161A; WO2011064802A1; EP2421694B1; CN102712161B

Abstract

A method and a machine for continuously manufacturing shopper bags with flexible handles of non-weldable and non-glueable material, in particular a pair of textile cord handles comprising preparing flexible handles already fitted with metal crossbar terminals, covering the handle retaining terminals by means of a folded over lining flap, carrying out in sequence preparatory operations on sheet panels, pre-cut to size and pre-creased, and forming the bag over special parallelepiped forms mounted on a rotating table.

Description

METHOD OF FABRICATING SHOPPER BAGS AND ASSOCIATED AUTOMATED FABRICATION LINE

BACKGROUND

Technical field

The present invention relates to the methods for manufacturing shopper bags in particular made from paper in sheet form or multi-layered laminate and provided with flexible handles made of non-weldable and non-glueable materials.

Prior art

In the consumable goods retail sector bags of varying shapes and sizes are used, said bags being made from different materials, typically plastic material, paper material or multi-layered laminates consisting of a paper sheet and plastic film which are bonded together, and being provided with handles, integral therewith or mounted thereon, for facilitating transportation of the products purchased. These bags also constitute an extremely important advertising means since the brand of product purchased or the name of the shop or retail distribution chain are commonly displayed on them.

One category of such bags, commonly referred to as "shopper bags", represent for operators in the sector highly attractive and practical bags which are suitable as a high-quality and prestigious medium for publicising the brands or names printed on them. They are usually made of paper in sheet form or a multi-layered laminate suitable for high-quality printing and often have a pleated structure and are provided with flexible handles made of soft textile-fibre cord which, while being pleasing in terms of feel and appearance, cannot be directly welded or glued onto the sheet forming the bag. The two ends of these handles must therefore be both passed through holes in the sheet or multi-layered laminate of the bag and stopped by knots which must be necessarily tied manually. European patent EP 1,440,897, in the name of the Applicant, describes an efficient, crimpable, metallic, crossbar terminal piece for flexible handles, the method for manufacturing the handles on an automatic production line and the procedure for mounting these handles with crossbar terminals through holes which are specially formed close to the edge of a pre-formed bag.

This latter solution, although reducing the costs of preparing and mounting textile cord handles because of the crossbar stopper terminals already crimped at the handle ends by special automatic machines, leaves the pairs of metallic terminals exposed inside the upper rim of the bag. Although the terminals have a smooth convex or tub-like form free of any projecting roughness, exclusion of any accidental interference when the products purchased and carried are introduced into and removed from the shopper bag cannot be guaranteed.

For this reason, high-quality shopper bags usually have soft textile cord handles, the ends of which are yet manually knotted in order to prevent them from coming loose. These laborious "back end" assembly operations, although they may be given out to be performed by low labour costs service companies, have yet a considerable impact on the cost of the finished shopper bag.

The search for a way of reducing the cost of producing high-quality shopper bags with flexible handles made of material which cannot be either welded or glued has hitherto posed an unresolved challenge so far certain quality requisites have represented an obstacle to achieving completely automated manufacture without the need for laborious back end manual operations.

SUMMARY OF THE INVENTION

The applicant discloses herein a method for continuously manufacturing shopper bags with flexible handles made of non-weldable and non-glueable material, which can be completely automated, thereby eliminating any manual operation for applying a pair of handles to the bag, while ensuring also the absence of exposed handle retaining terminals that couldnegatively interfere when using the shopper bag. This disclosure also discloses an efficient production line for fabricating shopper bags using the novel method, wherein no manual operation of any kind is required.

Essentially, by providing flexible handles already fitted with crossbar terminals in accordance with the above-cited prior patent in the name of the same applicant, the fabrication process envisages performing automatically and in sequence the following preparatory operations on flat panels which have been pre-cut to size and pre-creased for applying stiffening reinforcements and handles before finally forming the bag using specific parallelepiped forms for each bag format to be produced mounted on a rotating table: a) applying glue in areas, defined by crease lines, adjacent and parallel to a folding rim lining flap cut at one end along the side of the panel intended to constitute the rim of the bag, and on the same flap cut at one end and on one of two longitudinal edge portions of the flat panel; b) gluing at least two strips of a reinforcing material onto said areas defined by crease lines, each strip having length corresponding to the length of the longer sides of the rim of the parallelepiped bag being formed; c) punching two pairs of holes through the laminate formed by the reinforcing strips and by the sheet material of the panel; d) passing the crossbar terminals at the two ends of each of the two handles through the holes formed in the areas reinforced by said strips; e) folding over and adhering said rim lining flap of the sheet, except for its cut end part, onto said reinforcing strips and said crossbar terminals of the two handles, which have been passed through the holes; f) folding the pre-creased flat panel, wrapping it around a parallelepiped form retaining on one side thereof a flat insert of a stiffer material them the sheet material of the panel for reinforcing the bottom of the bag being formed and on the outward surface of which glue has been applied in predefined areas, overlapping and adhering together opposite longitudinal edge portions of the panel, forming a parallelepiped tubular article around said form, folding and adhering the cut end part of said flap for completing the lining the rim of the bag onto the glued overlapped longitudinal edge portions of the tubular article; g) folding two opposite pre-creased bottom closing flaps and then a third pre-creased bottom closing flap adhering them onto the glue-coated areas of said flat insert of bottom reinforcement retained on the side of the parallelepiped form, and applying glue onto the outer surface of the third folded bottom closing flap glued to the flat insert; h) folding the fourth and last per-creased bottom closing flap onto the three flaps glued to the flat insert, adhering it onto the glue coated surface of said third flap, pulling off/expelling the finished bag from the form, folding the pleat creases and collapsing/flattening the bag to a form suitable for packaging, storage and transportation.

Introducing the pairs of terminals from the outer side through holes in a pre- reinforced rim areas of a flat pre-creased panel of the sheet material of the bag and then folding over and adhering the rim lining flap on the reinforcements gluing it onto the inner side of the rim of the bag not only produces a stiffer bag rim owing to the glued strips of reinforcement applied along the longer sides of the rim, but also effectively lines the pairs of crimped sheet-metal crossbar terminals preventing any possibility of interference in a way which is perfectly compatible with the aesthetic and functional requirements of a quality shopper bag, without requiring any specific manual operation.

Forming the shopper bag around a parallelepiped fold form, gluing of superimposed longitudinal edges, applying a bottom reinforcing flat insert to one side of the parallelepiped form, folding and gluing bottom closing pre-creased flaps,pulling off/expelling the finished shopper bag from the form and folding the pleat creases for collapsing/flattening the bag are all operations which are can be performed in an entirely automatic manner using conventional handling members in respective workstations along an entirely automated production line reached incrementally in succession by the yet flat panel and by the bag being formed around a parallelepiped form, thus achieving the goal of fabricating high-quality shopper bags with negligible labour costs, in a mass production scale with a high production yield.

The invention is defined in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the invention will emerge even more clearly from the following detailed description of a practical example of embodiment of the invention, with reference to the accompanying drawings in which:

Figure 1 is an overall diagram of the method for continuously manufacturing shopper bags according to the present invention; the sequence of photographs in Figures 2 to 13 illustrates the steps for forming the shopper bag;

Figure 14 is a simplified plan view of the rotating table and the three stations for forming the bag and the auxiliary station for applying a bottom reinforcement flat insert onto the form;

Figure 15 is a simplified three-dimensional illustration of the group of stations around the rotating table;

Figure 16 is a simplified three-dimensional illustration of the components of the auxiliary station for applying the flat bottom reinforcement insert onto the form; Figure 16b is a simplified three-dimensional illustration of a parallelepiped form and the mounting components on the rotating table;

Figure 17 is a simplified three-dimensional illustration of the components of the station for forming the tubular article;

Figure 18 is a simplified three-dimensional illustration of the components of the station for folding over and gluing pre-creased bottom closing flaps onto the bottom reinforcement flat insert;

Figure 19 is a simplified three-dimensional illustration of the components of the station for folding over and gluing the fourth and last pre-creased bottom closing flap.

DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

The detailed description of embodiments of the invention with reference to the drawings has a purely illustrative intent, being possible for the invention to be practiced in marginally different ways and/or using devices of shape and characteristics different from those of the examples described.

With reference to Figure 1 , the various operations performed in sequence on the article being manufactured, as well as the work stations along a fully automated production line, numbered sequentially from 1 * to 10* in the sample embodiment shown, will now be described.

As can be seen, a fresh panel P of any suitable sheet material, such as pre printed paper or a multilayer laminate, already cut to size, scored and creased so as to define all the fold lines envisaged for forming a shopper bag is taken from a supply magazine mP (position 1 *).

In position 2*, glue is applied on two areas 1 , defined by crease lines, adjacently and parallel to a folding flap 5 that will serve for lining the rim of the bag, cut at one end so as to define a tongue 5b, and on the surface of the flap 5+5b itself. In position 3*, conventional automatic handling members remove from a supply magazine m2 two strips of reinforcing material 2, gluing them onto the respective areas 1 where the glue has been applied.

In position 4*, two pairs of holes 3 are punched through the laminate formed by the reinforcing strips 2 glued onto the areas 1 of the panel P.

In position 5*, suitable handling members 4m insert, from underneath, metallic crossbar terminals 4c crimped onto the two ends of each of two textile cord handles 4, through the respective pairs of holes 3 which have been previously formed in the areas reinforced by the strips 2.

In position 6*, the rim lining flap 5 defined by the outermost crease line along the edge of the panel, except for the end part cut so as to define a tongue 5b that during this step remains extended (open), is folded over and glued onto the reinforcing strips 2 and onto the two pairs of crossbar terminals 4c of the two handles 4, covering them and thus shielding them from any possible interference when introducing and removing goods from the shopper bag.

The flat panel P with the pair of handles 4 applied beforehand along the edge which will constitute the rim of the bag, reaches the position 7*, where conventional automatic components position it, performing a first fold along parallel crease lines, underneath one of four parallelepiped forms F installed at respective cardinal points (angular intervals of 90°) onto a rotating table TR.

In the position 8PRE, conventional automatic handling means of an auxiliary work station apply a bottom reinforcement flat insert fr, for example of cardboard, picking it up from a supply magazine mfr, onto the side outwarldy oriented of the form F provided with suckers or other releasable retaining means. .

In the first forming position 8*, automatic positioning means advance the panel P under the form F moving it forwards until the surface of the bottom reinforcement flat insert which is retained on the outward end face of the form coincides with the plane intercepting the crease lines of the sheet of the panel P for the subsequent folding of four bottom closing flaps and thence moving wings wrap the sheet around the form F, folding it along longitudinal crease lines until a longitudinal edge portion overlaps the opposite longitudinal edge portion 6 of the panel on which the glue has been applied, adhering them together and thus forming a parallelepiped tubular article S. Finally the tongue 5b is folded and glued onto the inner side of the rim so as to complete its lining.

Once the position 9* is reached, actuator members of the automatic station fold two opposite creased bottom closing flaps 7 and 8 onto the outer surface of the bottom reinforcement flat insert fr, adhering them to it, and then similar members fold over and glue a third creased bottom closing flap 9 on the outer surface of which glue is applied, while the fourth and last creased flap 10 remains open and extended.

In position 10*, handling members complete the closing of the bottom of the bag, by folding the fourth and last creased bottom closing flap 10 onto the outer surface of the third flap 9 onto which glue has been applied.

Having completed the closing of the reinforced bottom, the bag S is pulled off/expelled from the form F, which being freed of the bottom reinforcement, insert fr returns to the auxiliary position 8PRE, ready to start a new forming cycle.

In practice the process requires the use of four forms F advancing incrementally by a quarter of revolution at the time of the rotating table TR on which the forms are mounted.

The finished shopper bag S is eventually rotated and collapsed along the crease lines of the pleats and unloaded from the automatic production line.

The handles 4 provided with sheet-metal crossbar terminals 4c crimped onto the end of a textile cord may be prepared beforehand using a special automatic machine Aux which is schematically indicated alongside the front end line of the plant as shown jn FIG. 1 , wherein special pre-formed deep drawing, tub shaped thin metal are crimped in pairs one adjacent to another, at predetermined intervals on a textile cord which is then cut between the two adjacent terminals of each pair.

Commercially available machines of this type are produced by the applicant as described in the European patent EP 1,440,897.

The series of Figures 2 to 13 show photographic representations of the entire sequence for manufacturing shopper bags according to the method of the present invention.

Figure 14 is a simplified layout view showing the arrangement of the three bag- forming stations 8*, 9* and 10* and of the auxiliary station 8PRE around the rotating table TR onto which the four parallelepiped forms F are installed fixing them to special mounting brackets 11.

Figure 15 is a simplified photographic illustration of the work assembly organized around the rotating table.

With reference to Figures 16 and 16b, the forms F may be fixed to respective brackets of the rotating table by means of quick-release connectors which allow easy engagement of the form F provided with a connection plate to a support bracket 13 provided with pneumatic actuators 14, 15 for raising, lowering and rotating the form.. The parallelepiped forms F may be made of plastic, wood or wooden composite and are equipped with suckers and air-jet blower nozzles or equivalent devices (not shown in detail in the figures) based on conventional automation technology. The suckers are for retaining a cardboard reinforcement insert fr for the bottom on the outward side of the form F . The air blower nozzles are used to create an air cushion between the form and the formed bag for favouring expulsion of the finished bag from the form after having closed its bottom. The forms F have a cut off corner 16 in the corner zone that is reached by the glue bearing tongue 5b that remains extended and open during the adhesion of the rest of the edge 5 onto the reinforcing cardboard inserts 2 and the card handles terminals 4c, in order to allow overlaying and gluing together of the longitudinal edges of the panel over the form in order to form the tubular article, before folding over the glue bearing tongue 5b and adhering it onto the inner side of the sheet of the bag so as to complete the lining of the upper rim of the bag.

With reference to the components shown in Figure 16, the bottom-reinforcing cardboard inserts are stacked vertically inside a special adjustable magazine 17. A piston 18 ensures that the stack of cardboard inserts is always pressed against the removal wall of the dispensing magazine.

A first group of suckers 19 adhere to the cardboard insert, extracts it from the magazine by means of a cylinder 20 and, via a slider/recirculating ball guide drive system and pneumatic cylinder 21, the cardboard insert is conveyed towards the second group of suckers 22, situated opposite the first group, which pick up the cardboard insert at the middle. The first group of suckers is retracted, freeing the zone through which the form passes. When the rotating table completes the next quarter of a turn, it alignes with the second group of suckers which, moved by a pneumatic cylinder 23 towards the centre of the rotating machine, pass the bottom reinforcing cardboard insert to the suckers present on the receiving side of the form. During this step, glue is applied in predetermined zones on the surface of the bottom-reinforcing cardboard insert, onto which folded bottom closing pre- creased flaps of the sheet of the bag will be glued.

With reference to Figure 17 which shows some of the components of the first wrapping station 8*, two horizontal plates 24 and 25 carry away from the last station reached by the panel P, along the entry line to the forming unit organized around the rotating table, the panel P already fitted with cord handles 4 and with the upper rim lining flap of the bag folded over, except for a tongue part 5b that will be closed after the tubular article has been formed.

During the advancing movement of the flat panel P underneath the form F, glue is applied along the longitudinal edge portion 6 of the sheet. Two folding plates (cheeks) 26 and 27, operated by respective brushless motors 28 and 19 via belts with pulleys and a sliding movement on recirculating sliders and associated guides, move vertically from the bottom upwards, wrapping the creased sheet around the parallelepiped form. The top ends of the plates 26 and 27 have domes 28 which, with opposite and sequential horizontal movement, perform longitudinal closing of the tubular article S, adhering the longitudinal side edge flap 6, previously coated with glue, onto the opposite longitudinal edge portion of the sheet panel. Each dome is operated by a respective piston 29 which, via a system of levers, causes a pinion to rotate on a rack 30.

With reference to Figure 18 which shows some of the components of the second wrapping station 9*, the bag S still in the form of a tubular article wrapped around the form undergoes folding and gluing, onto the reinforcement insert, of the two shorter bottom closing pre-creased flaps of the sheet of the bag.

The components of this station form two symmetrical units 33, 34 operating simultaneously, one at the top and the other 34 at the bottom, the height thereof being adjustable as well as the gap between the operating units components and their position (more or less towards the centre of the rotating machine), so as to adapt to the different sizes of the bags to be produced and freeing automatically the zone through which the forms pass. Each unit has a rotating actuator 35 that fold over the two opposite bottom closing pre-creased flaps (the upper flat and lower flap relative to the position of the form) onto the bottom bottom reinforcement flat insert fr which is retained on the outward side of the form, adhering them onto it. Two double side stops 36, operated by pneumatic cylinders 37, move towards the respective folding members 35 for pressing on them the pre- creased flaps, leaving clear the pre-crease lines of definition of the other two flaps, which during this operation remain open and successively pressing and adhering the third bottom closing flap. In this station suitable actuators apply glue onto the outer side of the last adhered flap, that leaving yet extended open the past fourth bottom closing flap which will be adhered during the next step. A conventional , cylinder 38 moves the entire system of the two units 33 and 34 towards the form.

With reference to Figure 19, which shows some of the components of the third and last wrapping station 10*, after the closing of the bottom of the bag has been completed, the bag is expelled/ pulled off the form onto which it has been formed and unloaded from the operating unit organized around the rotating table.

The handling members of this station are connected together and all the adjustments are performed simultaneously and automatically by means of a toothed-belt device and associated pulleys operated by a controlled motor 39, for simplifying and making quick adaptation of the operating members of the station to the size of the bag being made.

Final closing of the bottom of the bag is performed in this last station by two units, symmetrical with each other and the form. The two units operate in sequence and are driven by two pneumatic cylinders 40 and 41 , respectively. Each unit has a wing with a right-angled profile, 42 and 43, respectively, that moves towards the form and folds the last bottom closing flap of the pre-creased sheet onto the bottom reinforcement piece fr held on the outward face of the form and adheres it over the glued outer side of the last adhered third flap.

With the bottom of the bag definitively closed, the two wings open up again and the entire operating unit moves towards the centre of rotation of the rotating table, where a rear pad reinforces the adhesion of the bottom closing flaps.

Expulsion/extraction of the finished bag off the form is performed by two columns of suckers 44 and 45, one on each side of the bag, and is assisted by air jets given off by nozzles or diffusers in the form.

Preferably, two small thin wheels (not shown in the figures), positioned, one underneath and the other above the bag, pass over longitudinal pre-crease pleat lines of the bag during its extraction from the form, for "activating" the folding lines to favour the subsequent collapsing of the pleats of the shopper bag upon unloading it from the production line in a collapsed form more suitable for packaging, storage and shipment of the shopper bags.

Claims

1. A method of manufacturing shopper bags made of a sheet of paper or of composite multi-layered laminate, provided with flexible handles of non- weldable and non-glueable material, comprising steps of preparing cut to measure and pre-creased flat panels adapt ed to be formed by folding and gluing into pleated bags of parallelepiped shape of a given size and of producing flexible handles with crossbar terminals crimped at the two ends of each handle, characterized in that the method comprises the following operations: a) applying glue in areas, defined by crease lines, adjacent and parallel to a folding rim lining flap, cut at one end, along the side of the panel intended to constitute the rim of the bag, and on the same flap cut at one end and on one of two longitudinal edge portions of the flat panel; b) gluing at least two strips of a reinforcing material onto said areas defined by crease lines, each strip having length corresponding to the length of the longer sides of the rim of the parallelepiped bag being formed; c) punching two pairs of holes through the laminate formed by the reinforcing strips and by the sheet material of the panel; d) passing the crossbar terminals at the two ends of each of the two handles through the holes formed in the areas reinforced by said strips; e) folding over and adhering said rim lining flap of the sheet, except for its cut end part, onto said reinforcing strips and said crossbar terminals of the two handles, which have been passed through the holes; f) folding the pre-creased flat panel, wrapping it around a parallelepiped form retaining on one side thereof a flat insert of a stiffer material than the sheet material of the panel for reinforcing the bottom of the bag being formed, on the outward surface of which glue has been applied in predefined areas, overlapping and adhering together opposite longitudinal edge portions of the panel, forming a parallelepiped tubular article around said form, folding and adhering the cut end part of said rim lining flap for completing the lining the rim of the bag onto the glued overlapped longitudinal edge portions of the tubular article; g) folding two opposite pre-creased bottom closing flaps and then a third pre-creased bottom closing flap, adhering them onto the glue-coated areas of said flat insert of bottom reinforcement retained on the side of the parallelepiped form, and applying glue onto the outer surface of the third folded bottom closing flap glued to the flat insert; h) folding the fourth and last per-creased bottom closing flap onto the three flaps glued to the flat insert, adhering it onto the glue coated surface of said third flap, pulling off/expelling the finished bag from the form, folding the pleat creases and collapsing/flattening the bag to a form suitable for packaging, storage and transportation.

2. The method according to Claim 1, wherein said flat bottom reinforcement insert is retained by one or more suckers present on said side of the parallelepiped form.

3. The method according to Claim 1, wherein said handles are of textile- fibre cord and said cross bar terminals are of deep drawn sheet metal tubs of size adapted to receive inside a cut end of the cord onto which the flanks of the deep drawn sheet-metal tub are crimped.

4. An automatic machine for continuously manufacturing shopper bags of a sheet of paper or of composite multi-layered laminate, provided with flexible handles of a material that cannot be glued or welded to the sheet material of the bag, for producing pleated bags of parallelepiped form and of a given size, by folding and gluing pre-creased panels cut to size, , comprising: a line of incremental advancement of said flat panels to workstations reached in succession by each panel at every incremental advancement, including workstations for applying glue onto given areas of the flat panel, for picking up and applying reinforcement strips for the longer sides of the rim of the parallelepiped bag, for punching holes through the areas reinforced by said strips, for passing crossbar terminals of textile cord handles through said holes, for folding over and gluing a rim lining pre-creased flap, except for a cut end part thereof, onto said reinforcing strips and said crossbar terminals of the cord handles; a group of workstations for forming the bag, organized around a rotating table incrementally advancing by a quarter of a revolution parallelepiped forms of size adapted to the size of the parallelepiped bags around which the parallelepiped bags being made flat sheet panels exiting said line, are formed, the groups comprising:

1) an auxiliary workstation having handling means adapted to pick up a bottom reinforcement flat insert from a supply magazine, place the insert onto retaining means present on the side of the parallelepiped form oriented outward of the rotating table and apply glue on predetermined areas of the insert retained on the side of the form;

2) a first forming workstation of a parallelepiped tubular article from the flat panel taken from the final station of said line, having handling members adapted to fold the pre-creased sheet panel along parallel longitudinal pre-crease lines around the parallelepiped form carrying said insert, overlap and glue a longitudinal edge portion over the other edge portion of the sheet and folding over and gluing said cut end part of the rim lining flap on the inner side of the rim, onto the glued overlapped edge portions of the tubular article;

3) a second forming workstation having handling members adapted to fold along pre-crease lines of the sheet and glue two opposite bottom closing flaps and thereafter a third bottom closing flap onto respective glue beaming areas of the bottom reinforcement insert , said insert being retained yet on said side of the parallelepiped form, and apply glue on the outer surface of said third bottom closing flap folded over and glued to the insert;

4) a third and last forming workstation for completing the closure of the bottom of the bag, provided with handling members adapted to fold and glue a fourth and last pre-creased bottom closing flap onto said the third bottom closing flap, pulling off/expelling the finished bag from the form releasing the bottom reinforcement insert, folding in the pleating creases, collapsing/flattering the bag to a form suitable for packaging, storage and transportation.

5. Machine according to Claim 4, wherein said parallelepiped forms have one or more suckers on the side oriented outward of the rotating table, for retaining said flat insert of bottom reinforcement until the formed bag is to be expelled from the form.