CN1646384A

CN1646384A - Plastic barrier closure and method of fabrication

Info

Publication number: CN1646384A
Application number: CNA038082039A
Authority: CN
Inventors: T·T·申克; A·J·F·托帕
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 2002-04-11
Filing date: 2003-04-10
Publication date: 2005-07-27
Also published as: MXPA04009816A; WO2003086890A1; US20030222046A1; BR0308962A; CA2481398A1; EP1494932A1; NZ535417A; IL164102A0; CO5631423A2; JP2005522383A; KR20040097314A; AU2003224924A1

Abstract

The present invention relates to a plastic barrier closure (or cap) for bottles and the like that has (1) a body having a top wall, a side wall, a securing means and a seal that has at least one concentric sealing member extending from the top wall, and (2) a barrier incorporated into the top wall. The barrier layer may be incorporated into the top wall by (1) depositing a melted mass of barrier polymer in the pre-molded cap body and then molding it into place by mechanical means or (2) forming a barrier layer from the barrier polymer and inserting it into a pre-molded cap body.

Description

Gas barrier vinyl cover and production method

The background of invention

Field of the present invention

The present invention relates to for example vinyl cover (or cap) of glass bottle and PET bottle and so on container.This bottle cap has barrier layer (barrier), can prevent for example carbon dioxide and oxygen and so on gas permeation, also is not easy to the odour-producing component of " blowing (scalp) off " packaging product.A kind of like this production method of lid has also been described.

Description of related art

Can buy from the market for many years comprising glass bottle and plastic bottle vinyl cover at interior packing container.The most general vinyl cover example all be in lid car screw thread so that they are screwed in various beverages are housed, on the PET bottleneck comprising carbonated soft drink.The most general caps for carbonated soft drinks comprises the molded polypropylene body skin, and a kind of common inner lining material made from the ethylene vinyl acetate polymer cmpd is arranged in its housing.Can adopt injection moulding or compression moulding method to produce this housing.Install and be lined with two kinds of methods in this: 1) " sandwich " (pick and place), wherein adopt mechanical means that the material disk of pre-molding is put in this housing, 2) " housing inner mold " wherein is put into a spot of melted material in the housing, uses the pot plunger in-place molding then.This lid liner plays the effect of mechanical gasket or sealing member, and it can prevent that carbon dioxide from leaking from lid.These lids are referred to as " biplate " lid.

Recently, on market, thrown in another design-calculated lid.Be referred to as " whole (one-piece) " or " no liner " lid, these lids are to use the mono-poly-mer, injection moulding that very general HDPE makes or compression moulding lid.The example of these lids: US 3 948 405, US 4 526 284, US 4 739 893 and US 5,743 420 have been described in the patent that is referenced by reference below.Combine with the suitable of material by the geom design, these lids can provide suitable mechanical seal, prevent for example carbon dioxide leakage of soda.

Although lid design described above can provide the favorable mechanical sealing, prevent gas leakage, can't prevent effectively that gas from passing through the infiltration of tegmental wall, because the gas barrier relative mistake of normally used polyolefin polymer.For some packaging applications, need better barrier layer, prevent to breathe freely.

A lot of approach that obtain to have the vinyl cover that improves barrier layer were once described in the prior art.A kind of approach is to be substituted in the liner that uses in two lids with the liner that the gas barrier material is made.Multiple-structures are used in EP 62340 instruction, and wherein one deck is to prevent the barrier layer of breathing freely at least, and one deck plays the effect of mechanical seal layer at least.JP-07137754 has described a kind of lid, and this is stamped the multilayer liner, and barrier layer and sealing layer are wherein arranged, and the lid of molding on liner is arranged.EP 926 078 has described a kind of sealed liner of mainly alternately being made up of base material layer and gas barrier material layer.In EP62 340 and EP 926 078, the barrier layer effect that the liner of description can play the mechanical seal effect that prevents gas leakage and prevent to breathe freely.EP 233 414 discloses the approach of another kind of acquisition gas barrier lid, and this approach is to use the common vinyl cover of the coating coating of " saturating steam material " (supposition a slice or two), and this paint solidification generates solid, and sticks to this all the time and cover.

Another gas barrier lid notion is with a kind of no liner design-calculated lid of the manufacture of materials with good barrier properties rather except that preferred HDPE.But very common barrier polymer is easy to hardening, and is not flexible, therefore is difficult to reach the favorable mechanical leak tightness, prevents gas leakage.

Description of the invention

The invention provides a kind of container, the container of outside thread neck particularly arranged, for example the bottle etc. vinyl cover (or cap), can fill or the emptying container by its neck.Container neck or vessel port are tubular portion, and the one end links to each other with container, and opposite end opens wide (top or ring gear (rim)).This ring gear has inner edge and outside.This tubular portion has inside face and outside face.Preferably, screw thread is arranged on the outer surface, a position between these screw threads extend between this tubular portion top and bottom from the top.Preferably, during the screw thread of the screw-threaded engagement bottleneck outside of lid the inside, this lid just is clasped in (or screwed to) on the bottle.Can adopt other lid and the tight way of bottle fastener.

This is stamped the barrier layer that prevents gas permeation, is not easy to absorb the odour-producing component of packaging product.This lid comprises lid and barrier layer.

This lid comprises:

A, there are the disk shape upper wall of inside face, its inside face to be configured to make when being engaged on neck the contact or the ring gear of contacting container neck almost,

B, cylinder side wall, it is linked upper wall and begins to extend from upper wall;

C, with lid and neck buckled up parts, this parts preferably include the negative thread on the cylinder side wall, it can be engaged on respective threads on the exterior; And

D, sealing member, when lid installed on the container, the sealing part provided the favorable mechanical sealing, prevents gas leakage.

The sealing part comprises the containment member that at least one can be linked the upper wall inside face and begin to extend from the upper wall inside face, it is concentric with the face of cylinder, and be configured to when lid meshes with neck, can contact continuously (the interior or outward flange of ring gear top, ring gear, or neck sidewall) with container neck.

Perhaps, the sealing part can comprise:

The i outside seal may, it can be linked the upper wall inside face and begin to extend from the upper wall inside face, and is configured between the inside face of cylinder side wall and bottleneck outward flange so that lid and neck when meshing can with the top outer edge uninterrupted contact of the ring gear of container neck; And

The ii inner seal liner, it is concentric with outside seal may, and extends from lid upper wall inside face so that lid when meshing with neck can with ring gear inward flange uninterrupted contact.

The lid moulded plastic, most preferably HDPE makes.

The barrier layer that is added to the lid upper wall is selected from known material, and these materials provide and prevent the good barrier layer of breathing freely, and also are not easy to absorb the odour-producing component of packaging product.The gas barrier material can be any poly-mer in many barrier polymers, comprising EVOH, nylon and polyester (comprising 2GT, 3GT and 2GT and 3GT polyester blend).Preferably amorphous nylon or 3GT polyester.Barrier layer also can be metal, for example aluminium.

A kind of selectable specific embodiments comprises lid and sealing member, the sealing part has single sealing element, these parts are connected on the upper wall inside face and begin to extend from the upper wall inside face, and configuration make when lid meshes with container neck can with container rim outward flange uninterrupted contact.When only using the outer gland sealing parts as sealing member, when lid meshed with container neck, the gas barrier material preferably contacted with the ring gear of container.

Can adopt a kind of method of following two kinds of methods that barrier layer is added in the lid:

A, the barrier polymer fused mass is put in the pre-molding lid, adopts mechanical way to carry out molding in the original place then.This method is referred to as " shell inner mold " method.

B, make barrier layer with division step, in the pre-molding lid of packing into then.This method is referred to as " sandwiching " method.

Accompanying drawing is briefly described

Fig. 1 is the vertical sectional view of expression the present invention lid, and this lid can be applicable to container neck.

Fig. 2 is that expression the present invention lid is contained in the vertical sectional view on the container, and wherein interior concentric ring provides mechanical seal.

Fig. 3 is that expression the present invention lid is contained in the vertical sectional view on the container, and its China and foreign countries' concentric ring provides mechanical seal, and barrier layer plays the effect of positive stop.

Fig. 4 is that expression the present invention lid is contained in the vertical sectional view on the container, has the another kind of selectable structure of Fig. 3, and its China and foreign countries' concentric ring provides mechanical seal, and barrier layer plays the effect of positive stop.

Describe in detail

What the invention provides airtight container neck opening end is generally columniform vinyl cover (or cap), and the good barrier layer that prevents gas permeation and be not easy to absorb packaging product odour-producing component in the airtight container is provided with this this lid.A kind of like this lid is particularly useful as the lid of glass bottle and PET bottle, for example is used for the lid of carbonated soft drink, beer and other beverage bottle.This lid can randomly comprise assurance ring or tamper-evident strip.This lid comprises becoming the lid (promptly have the upper wall that is generally the disk shape and cylinder or pipe sidewall sections, this part is vertical with upper wall basically and begin extension from upper wall) of bottle-cap shaped and is added to the barrier layer that covers wall.

Referring to constitute this specification sheets openly the accompanying drawing of part can more be expressly understood this lid, this lid provides the parts of mechanical seal when having lid and container buckled up parts and lid and container fastening.

As described in Figure 1, the parts of this lid of fastening typically with container neck outside thread ingear negative thread.Utilize when describing the present invention and cover, should be appreciated that, design, use other buckled up parts like this can realize these fringe benefits as the lid that adopts crown plug or omnia class with the container neck screw-threaded engagement.

Provide the parts of mechanical seal to preferably include one or more containment members, this member is connected in the inner top of lid, and extends thus, so that its lid fastening contacts with the neck of container on container the time.

Fig. 1 and 2 explanation is applied to the lid of the present invention of container neck, and lid 1 comprises upper wall 2, negative thread sidewall 3 and sealing member 4.The sealing part can be made up of interior concentric ring 4a, outer concentric ring 4b or both.The sealing part extends downwards from the upper wall inside face, and is configured to mesh the neck of this container, can reach the favorable mechanical sealing so that its lid is screwed to when bottle last, prevents gas leakage.Should be understood that lid 1 can also have different structures.Prior art has the design of many such vinyl covers, and wherein one or more parts of lid are configured to mesh container neck, realizes the favorable mechanical sealing, prevents gas leakage.The sealing part can be configured to be engaged on the container neck of ring gear 7 or inwall 8 or outer wall 9.This class lid is referred to as " integral cap " or " no liner lid ".

Lid can be made with many plastics, comprising polyolefin, and for example high density polyethylene (HDPE) (HDPE), low density polyethylene (LDPE) (LDPE) and polypropylene (PP), nylon, polyvinylchloride, polycarbonate, polystyrene and polyester.Usually, although can use heat cured poly-mer, preferably thermoplastic poly-mer.For many packaging applications, particularly for the packing carbonated soft drink, HDPE is a preferred material of making lid.One group of mechanical characteristics of HDPE (bending modulus and hardness especially) is very suitable for producing a kind of to container rim actv. mechanical sealing member.Packaging applications for relating to hot charging or distillation methods (retort process) depends on pressure and temperature, and HDPE can not have enough resistances to effect of heat as cover materials.In these were used, resistance to effect of heat was higher than the material of HDPE, and for example polypropylene or nylon are preferred.Adopt common thermoplastic plastic job operation, for example compression moulding and injection moulding process can be produced this lid.

Can be somebody's turn to do the barrier layer 5 of lid with many common gas barrier manufacture of materials, comprising amorphous nylon, semicrystalline nylons, ethylene-vinyl alcohol copolymer (EVOH), Vingon (PVDC), polyester (PE), comprising 2GT, 3GT polyester and 2GT and 3GT polyester blend material, and polyacrylinitrile.Also can use metal, for example aluminium is produced this lid barrier layer, but usually, the plastic barrier material is preferred.The barrier layer of lid plays and prevents gas, and for example carbon dioxide and oxygen are by the osmosis of lid.It also is not easy to the odour-producing component of absorption or " blowing off " packaging product, or gives this product undesirable component.The preferred material of barrier layer is an amorphous nylon, for example the Selar  PA of E.I.du Pont de Nemours and Company.For the packing of liquid, in common gas barrier material, amorphous nylon provide gas barrier property and non--blow off can best of breed.Another kind of preferred material is the 3GT polyester, and it has good gas barrier properties and the performance that is easy to process.Especially, 3GT can process under than the lower temperature of the fusion temperature of other common barrier polymer.

Barrier layer is added in the lid can the whole bag of tricks, comprising following method.

1) gas barrier material melt is put on the upper wall inside face of preforming lid, uses then to drive the pot plunger in-place molding, generate last barrier layer.This method is referred to as " shell inner mold ".Molten material can be common polymer melt, maybe can use chemistry or physical blowing agent to make the molten material foaming.Let-in gas barrier quantity of material is so controlled, so that the last size of barrier layer keeps within the acceptable range.The face of molding pot plunger is designed so that the exposed surface of barrier layer has desirable profile.

In Fig. 2, barrier layer 5 is flat.In Fig. 3 and 4, the profile of barrier layer 5 is so, so that the convex surface as container rim 7 limiting devices (stop) is provided.The diameter dimension of pot plunger is more slightly smaller than the minimum diameter of the inner seal ring of lid, makes when pot plunger is pressed into the gas barrier material of fusing in the lid that minimum gap is arranged between pot plunger and seal ring.The equipment that adopts this shell inner mold method is the many companies that obtain from the market, comprising the equipment of Sacmi and Oberburg Engineering AG.Employing barrier layer 5 directly sticks to the method on the lid, adopts mechanical means or adopts these two kinds of methods that barrier layer 5 is remained in the lid 1.Keep in order to reach machinery, lid 1 is preferably designed so that at seal ring 4b root undercut (undecut) 6, and as Fig. 3 and 4 illustrated, barrier layer 5 has one than the big slightly external diameter of seal ring 4b minimum diameter like this.

2) method that can separate of barrier layer 5 forms, and adopts mechanical means to be installed in the preforming lid 1 then, lid to the end.This method is referred to as " sandwiching " method.Adopt mechanical reservation method that barrier layer 5 is remained in the lid 1.

As Fig. 3 and 4 illustrated, lid 1 has been designed at seal ring 4b root undercut 6 is arranged, and therefore, produces close fit (interferencefit) between preformed barrier layer 5 and the lid 1.This preformed barrier layer must be enough soft, the free from flaw to hold out against installation process.This installation method is particularly suitable for metallic barrier layers and thermosetting plastic barrier layer, yet, if barrier layer is made with thermoplastic material, also can adopt this installation method.

Alternative method of a kind of the design's of preparation plastic barrier cap is the co-extrusion injection moulding process.In this method, use two extruding machines to produce melting materials capable; An extruding machine is used for cover materials, and second extruding machine is used for the gas barrier material.Molten material simultaneously or one after the other be added to die cavity is made last vinyl cover.The equipment that this method is used is more complicated than the equipment and the instrument of " inner casing molding " method or the use of " sandwiching " method with instrument, and cost is higher.

If the gas barrier of barrier layer material, is preferably to be up to few two quantity than high at least one order of magnitude of cover materials, advantage then of the present invention is very favorable (attendant).For example, a preferred specific embodiments of the present invention comprises HDPE lid and amorphous nylon barrier layer: the CO of amorphous nylon ₂Impermeability is than the high about 100x of HDPE.

In one embodiment of the invention, as shown in Figure 2, sealing member in the lid 1 just comprises the interior concentric containment member 4a that extends from upper wall 2 downwards, and when this lid was contained on the container, concentric sealing element 4a was configured to mesh the inward flange 7a of container neck ring gear in this.Perhaps, interior concentric sealing rings 4a can be configured to mesh the inwall 8 of container neck.Interior sealing element 4a provides mechanical seal, prevent gas leakage, and barrier layer 5 is main barrier layers, prevents gas permeation.

In a preferred specific embodiments of the present invention, as Fig. 3 and 4 illustrated, sealing member in the lid 1 just comprises the outer concentric containment member 4b that extends from upper wall 2 downwards, and when this lid was screwed on the container, this outer containment member 4b with one heart was configured to mesh the outward flange 7b of container neck ring gear.Perhaps, outer containment member 4b with one heart can be configured to mesh the outer wall 9 of container neck.Barrier layer 5 is put into lid 1, and preferably, adopt the mounting torque of forbidding, typically the 28-mm lid is 14-18 in-lb screw capping, to cover fastening when neck, barrier layer 5 is designed to contact with the upper limb 7 (Fig. 3) or the ring gear inward flange 7a (Fig. 4) of bottle ring gear.The design-calculated barrier layer can have a 7c (Fig. 3) of contact ring gear upper limb 7, or can gradient (Fig. 4), makes this barrier layer only contact inward flange 7a.In this specific embodiment, when this lid installed on the container, barrier layer 5 played the effect of positive stop.The mechanical seal of lid 1 outer seal member 4b is main, can prevent gas leakage, and the mechanical seal of barrier layer 5 is less important, can play main barrier layer, prevents the effect of gas permeation.In this preferred specific embodiments, when lid was properly installed on the container, packaging product did not have any direct contact with cover materials, also can reach best gas barrier property and the non-performance that blows off.

Recognize that the material of producing the use of lid and gas barrier liner can randomly use other material to carry out modification, and these materials are normally used in container cap and the lid industry.These modifier wherein can comprise pigment, slip agent and oxygen scavenger.

The present invention is generally practical to the PET bottle cap, will be appreciated that these lids can use on any class container that cylindrical neck portion is generally arranged, for example use glass, plastics or metal bottle or jar.

Claims

1, a kind of lid that is used to have the container of cylindrical neck portion, this cylindrical neck portion has outer wall, inwall and band inward flange and outer peripheral opening ring gear, and it comprises lid and barrier layer, wherein:

A. lid comprises:

(i), have the disk shape upper wall of inside face, its inside face to be configured to make when being engaged on neck the contact or the ring gear of contacting container neck almost,

(ii), the cylindrical lateral wall of inside face arranged, linking upper wall and when the neck that upper wall begins to extend substantially vertically meshes, this inside face contact or the neck of contact lid almost;

(iii), with lid and container neck buckled up parts; And

(iv), sealing member, wherein the sealing part comprises the containment member that at least one is linked the upper wall inside face and begins to extend from the upper wall inside face, it is concentric with the face of cylinder, and configuration makes uninterrupted contact container neck when lid and this container neck mesh; And

B. barrier layer is added to the upper wall of lid, this barrier layer is made with the gas barrier material of selecting, and prevents when providing the lid fastening on container neck ventilative and absorbs the barrier layer of the odour-producing component in the container contents.

2, lid according to claim 1, containment member and outer seal member in wherein the sealing part comprises:

A, outer seal member, it is linked the upper wall inside face and begins to extend from the upper wall inside face, with the face of cylinder be concentric, and configuration makes when lid meshes with container neck and the top outer edge uninterrupted contact of container neck;

B, interior containment member, it is linked lid upper wall inside face and begins to extend from the upper wall inside face, and is concentric with outside seal may, and configuration makes when lid and container neck mesh and container neck inward flange uninterrupted contact.

3, lid according to claim 1 and 2, wherein buckling clamping part comprises the negative thread of cylindrical side in facing the wall and meditating, the respective threaded on this screw-threaded engagement container neck.

4, lid according to claim 1, wherein sealing member comprises outer seal member, its configuration makes engagement container neck outward flange or outer wall, and its middle cover is when being contained on the container, the upper limb or the inward flange of barrier layer configuration engagement container neck.

5, lid according to claim 1 and 2, wherein lid is made with the thermoplastic material that is selected from polyolefin, nylon, polyvinylchloride, polycarbonate, polystyrene and polyester.

6, lid according to claim 5, wherein polyolefin is selected from high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene and polypropylene.

7, lid according to claim 1 wherein adopts the inner casing molding methods or sandwiches method, and barrier layer is added on the lid upper wall.

8, lid according to claim 1 and 2, wherein barrier layer is made with the material that is selected from amorphous nylon, semicrystalline nylons, ethylene-vinyl alcohol copolymer, Vingon, polyester and polyacrylinitrile.

9, lid according to claim 5, wherein lid is made with high density polyethylene (HDPE).

10, lid according to claim 8, wherein barrier layer is made with amorphous nylon or 3GT polyester.

11, lid according to claim 1, wherein container is the PET bottle.