CA2005689A1 - Easy opening plastic package - Google Patents

Easy opening plastic package

Info

Publication number
CA2005689A1
CA2005689A1 CA 2005689 CA2005689A CA2005689A1 CA 2005689 A1 CA2005689 A1 CA 2005689A1 CA 2005689 CA2005689 CA 2005689 CA 2005689 A CA2005689 A CA 2005689A CA 2005689 A1 CA2005689 A1 CA 2005689A1
Authority
CA
Canada
Prior art keywords
container
flange
package
layers
lid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA 2005689
Other languages
French (fr)
Inventor
John S. Thomas, Jr.
David E. Ofstein
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shell Internationale Research Maatschappij BV
Original Assignee
Shell Internationale Research Maatschappij BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shell Internationale Research Maatschappij BV filed Critical Shell Internationale Research Maatschappij BV
Publication of CA2005689A1 publication Critical patent/CA2005689A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D77/00Packages formed by enclosing articles or materials in preformed containers, e.g. boxes, cartons, sacks or bags
    • B65D77/10Container closures formed after filling
    • B65D77/20Container closures formed after filling by applying separate lids or covers, i.e. flexible membrane or foil-like covers
    • B65D77/2024Container closures formed after filling by applying separate lids or covers, i.e. flexible membrane or foil-like covers the cover being welded or adhered to the container
    • B65D77/2028Means for opening the cover other than, or in addition to, a pull tab
    • B65D77/2032Means for opening the cover other than, or in addition to, a pull tab by peeling or tearing the cover from the container
    • B65D77/2044Means for opening the cover other than, or in addition to, a pull tab by peeling or tearing the cover from the container whereby a layer of the container or cover fails, e.g. cohesive failure
    • B65D77/2048Means for opening the cover other than, or in addition to, a pull tab by peeling or tearing the cover from the container whereby a layer of the container or cover fails, e.g. cohesive failure whereby part of the container or cover has been weakened, e.g. perforated or precut
    • B65D77/2052Means for opening the cover other than, or in addition to, a pull tab by peeling or tearing the cover from the container whereby a layer of the container or cover fails, e.g. cohesive failure whereby part of the container or cover has been weakened, e.g. perforated or precut the container being weakened
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2577/00Packages formed by enclosing articles or materials in preformed containers, e.g. boxes, cartons, sacks, bags
    • B65D2577/10Container closures formed after filling
    • B65D2577/20Container closures formed after filling by applying separate lids or covers
    • B65D2577/2025Multi-layered container, e.g. laminated, coated
    • B65D2577/2033Multi-layered container, e.g. laminated, coated with one or more layers of container being torn off upon initial opening
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65DCONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D2577/00Packages formed by enclosing articles or materials in preformed containers, e.g. boxes, cartons, sacks, bags
    • B65D2577/10Container closures formed after filling
    • B65D2577/20Container closures formed after filling by applying separate lids or covers
    • B65D2577/2066Means on, or attached to, container flange facilitating opening, e.g. non-bonding region, cut-out

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Packages (AREA)

Abstract

A B S T R A C T

EASY OPENING PLASTIC PACKAGE

An easy opening plastic package which comprises a flanged container formed from a laminate which has at least two layers bonded together by a relatively weak adhesive which allows the layers to be easily pulled apart and wherein the container flange is formed with a crimp which is thin enough to weaken the flange sufficiently so that it breaks away easily when the two layers are peeled apart. Finally, the package includes a lid which is strongly attached to the container flange.

Description

;~005~89 EASY OPENING PLASTIC PACKAGE

This invention relates to plastic packages, especially those for food and other perishable items.
More specifically, the invention relates to plastic packages sealed with a lid which may be easily removed from the container portion of the package-.
Cup-like plastic containers for food and other products have been in use for many years. Very often, lids for such packages are formed from a metal foil which is attached to the container with an adhesive. --It has been desirable to make such lids easily re-movable from the container and this has commonly been done by using an adhesive which allows the user to easily remove the lid from the container and thus open the package.
In recent years, there has been an increase in the use of plagtic materials for lids for plastic -containers. This has caused a number of problems including the difficulty in manufacturing such a package such that the lid may be easily removed from the container. U.S. Patent 4,693,390 issued September 15, 1987 illustrates one attempted solution to this problem. Therein the lid is scored (cut part of the way through) at two points on the surface which is bonded to an internal flange of the container. The purpose of the scoring is to allow a major portion of the lid to be relatively easily pulled away from the container leaving a small portion of the lid attached thereto.
It is an object of the present invention to provide an easily openable plastic package wherein , - . . . . . . . . .

. , .. , , . . . . -,: , ,. , , , , , . , : , - , :', ., .

O(~S689 neither the lid nor the package are scored so that there is a continuous layer of protective material both on the inside and outside of both the lid and the container to provide maximum protection for the S contents of the package. This is especially significant when oxygen barrier materials are in-corporated into the plastic lid or container since it is undesirable to have 6uch materials or the adhesives by which they are bound to the protective layers come into contact with food or other sensitive materials.
Furthermore, some of the oxygen barrier materials may absorb moisture either from the outside or from the inside of the package and this would decrease their ; effectiveness as a barrier to oxygen.
Another ob;ect of the present invention relates to - the fact that there is no criticality in the location of the seal between the lid and the container flange.
In a package which utilizes scoring, the adhesive seal must be spaced from the scoring or else the container will tend to break at the score. In the package of the present invention, the burst strength of the package does not depend on locating the adhesive in a particular place with respect to the crimp, i.e. the adhesive is used all the way throughout the container flange including the area of the crimp.
The present invention relates to an easily opened plastic package which comprises a flanged container formed from a laminate comprising at least two plastic layers bonded together by a relatively weak adhesive layer which allows the plastic layers to be easily pulled apart, wherein the container flange is formed with a crimp which is thin enough to weaken the flange sufficiently so that it breaks away easily when the plastic layers are pulled apart, and a lid which is strongly attached to the container flange. In the .

~00~689 , - preferred case of oxygen barrier packages, the container will be formed of a laminate which comprises ~ an inner oxygen barrier layer and two outer protective ; layers bonded to the barrier layer by two adhesive layers. One of the adhesive layers is strong and the other i8 relatively weak to allow the outer layer with which it is in contact to be easily peeled from the barrier layer.
The base or protective layers are preferably polypropylene but may also be selected from any thermo-plastic which is capable of serving as a protective outer layer. The oxygen barrier layer is preferably an ethylene vinyl alcohol copolymer but may also be polyvinylidene chloride or other barrier polymers.
Figure 1 is a cut away cross section of an oxygen barrier package showing the flange of the container and the various layers of the laminate from which it is formed including the crimp and the lid attached thereto.
Figure 2 illustrates another embodiment of the invention wherein the container is formed of two base -layers bonded together by a weak adhesive and also illustrates how the peeling process is begun by pulling upwardly on the extended end of the lid.
Figure 3 illustrates the embodiment wherein the crimp is formed on the underside of the flange.
Figure 1 shows a portion of an oxygen barrier container 10 and illustrates the details of the container flange 12. The container 10 and flange 12 are formed of outer layers 14 of a base protective material, an inner layer 16 of an oxygen barrier -material, a layer 18 of the strong adhesive and a layer 20 of a relatively weak adhesive. The adhesives provide the adhesion between the outer protective base layers and inner barrier layers.

.

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", : - , . ' - , ,. . . . .. . . . .

.

--` 20135~i89 The outer base protective layers are preferably formed of polypropylene because it is inert to most food products and does not affect the flavor or odor of the product. Other inert strong polymers may also be used. The barrier layer is preferably formed of a copolymer of ethylene and vinyl alcohol because it has excellent oxygen barrier properties and is easily processable. Polyvinylidene chloride and other barrier polymers may also be used.
The strong adhesive may be, for example, maleic anhydride-modified polypropylene. The weak adhesive may be, for example, maleic anhydride-modified poly-ethylene or maleic anhydride-modified polypropylene blended with polypropylene or even just a maleic hydride-modified polypropylene with a low degree of functionalization.
As can be seen in Figures 1, 2 and 3, the container flange 12 has a crimp 22 therein. Figs. 1 and 2 show the crimp on the upper side of the flange and Fig. 3 shows it on the underside of the flange.
The crimp 22 weakens that portion of the flange 12 but still provides continuous unbroken base and barrier layers 14 and 16. The crimp may be formed into the container flange 12 in a secondary operation.
Preferably, the crimp is formed into the container flange 12 during the forming process wherein the container 10 is formed. This may be accomplished by a variety of means including thermoforming and injection molding.
The lid 24 is adhered to the upper portion of the container flange 12. The seal between the lid 24 and the flange 12 should be a so called "permanent"
seal-this means that the two layers should be extremely difficult to pull apart. Such a seal between the lid 24 and the flange 12 can be accomplished by a variety of means including virtually any sealing method-adhesion, ultrasonic, radio frequency, vibration welding, thermal conduction and spin welding, for example. In the case of the oxygen barrier package, the lid must also include an oxygen barrier material and preferably also include inner and outer protective base layers. If oxygen barrier is not important, then the lid may be formed of any plastic material, laminate - or otherwise.
Figure 2 illustrates the non-oxygen barrier embodiment of the present invention wherein the container flange is formed of a laminate of two outer base protective layers 14 adhered together by a layer 20 of a relatively weak adhesive. The lid 24 is permanently sealed to the upper portion of the flange 12 and, as in Figure 1, extends outwardly beyond the end of the flange 12.
As shown in Figure 2, to open this package, an upward force is exerted on the extending end of the lid 24. Because of the strong adhesion between the lid 24 and the container flange 12, the upper base layer 14 does not peel away from the lid 24 but rather the two base layers 14 peel away from each other at the adhesive layer 20 because of the relatively weak adhesion strength of that layer. When the peel reaches -the crimp 22, the outward portion of the container -flange 12 breaks off because the crimp 22 has weakened the flange 12 sufficiently at that point for such : breaking off to occur. This action provides the : 30 opening of the package. The same type of thing happens with the package of Fig. 1 except that the peel is between the base and barrier layers which are bonded together by the weak adhesive.
The characteristics of the weak adhesive are important to the performance of the package of the .. . .. . . ...
.. :... .. ... . ............... . .. ..

: :...
- ., : : : :,.

~`

present invention. In general, for shallow draw containers, the adhesive strength should be at or above 0.5 pounds per linear inch (PLI) and for deep draw containers, the adhesive strength should be at or above 1.0 PLI.

,- , , :, .
- , ~ , ,

Claims (5)

1. An easy opening plastic package comprising:
a) a flanged container formed from a laminate comprising an inner oxygen barrier layer, outer layers bonded to said barrier layer by two different adhesive layers, one which is strong and one which is relatively weak and allows the outer layer with which it is in contact to be easily peeled from the barrier layer, and wherein the container flange is formed with a crimp which is thin enough to weaken the flange sufficiently that it breaks away when said outer layer is peeled away from the barrier layer: and b) an oxygen barrier lid which is strongly attached to the container flange.
2. The package of claim 1 wherein the base layers are formed of polypropylene.
3. The package of claim 1 wherein the barrier layer is selected from the group consisting of copolymers of ethylene and vinyl alcohol and polyvinylidene chloride.
4. An easy opening plastic package comprising:
a) a flanged container formed from a laminate comprising two base layers bonded together by a relatively weak adhesive layer which allows the base layers to be easily peeled apart, wherein the container flange is formed with a crimp which is thin enough to weaken the flange sufficiently so that it breaks away easily when the base layers are peeled apart; and b) a lid which is strongly attached to the container flange.
5. The package of claim 4 wherein the base layers are formed of polypropylene.
CA 2005689 1988-12-29 1989-12-15 Easy opening plastic package Abandoned CA2005689A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US29171688A 1988-12-29 1988-12-29
US291,716 1988-12-29

Publications (1)

Publication Number Publication Date
CA2005689A1 true CA2005689A1 (en) 1990-06-29

Family

ID=23121523

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2005689 Abandoned CA2005689A1 (en) 1988-12-29 1989-12-15 Easy opening plastic package

Country Status (5)

Country Link
EP (1) EP0376413A1 (en)
JP (1) JPH02219771A (en)
AU (1) AU4692289A (en)
BR (1) BR8906711A (en)
CA (1) CA2005689A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU628723B2 (en) * 1990-03-30 1992-09-17 Sumitomo Bakelite Company Limited Easily openable sealed container and process for producing the same
DE102008038902A1 (en) * 2008-08-13 2010-02-18 Fritz Hark Orchideen Gmbh & Co. Kg container
NL2011432C2 (en) * 2013-01-18 2014-07-28 Naber Beheer B V PACKAGING, METHOD FOR MANUFACTURING A PACKAGING, AND MAY BE USED FOR THE PURPOSE OF SUCH A METHOD.

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1303522C (en) * 1986-04-08 1992-06-16 Takanori Suzuki Easily-openable packaging container
US4693390A (en) * 1986-10-15 1987-09-15 Continental Can Company, Inc. Lid for a plastic container

Also Published As

Publication number Publication date
AU4692289A (en) 1990-07-05
EP0376413A1 (en) 1990-07-04
BR8906711A (en) 1990-09-11
JPH02219771A (en) 1990-09-03

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Legal Events

Date Code Title Description
FZDE Dead