JPS5841058A - Easily unsealable package having recloseable characteristic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to packages of cheese, luncheon meats, etc. In particular, the present invention relates to an easy-to-open seal for such a package, and further to a means for closing such a package once it has been opened.

Today, products such as cheese and luncheon meats are
The package is packaged with a thermoplastic film layered around the circumference of the article to be packaged, and this film is heat sealed to itself to form a sealed seam. Films for packaging products such as cheese and luncheon meats that are difficult to open without making them unsuitable for further use are tough, can withstand abuse, and have the required gas permeability.
The problem is complicated by the fact that it must be possible to open the package without damaging the package while at the same time opening the package with a relatively small opening force. The purpose is to provide an airtight and sealing form that is covered but does not damage the package.

In the past, many types of seals have been provided with easy-to-open features. For example, U.S. Patent No. 2.96
No. 8,596 discloses opening and tearing characteristics in a thermoplastic film package in which gusseted folds provide tear tabs.

W, A, W@rk published October 27, 1970
U.S. Pat. No. 4,534,501 of OB@@rna@r describes a package in which the edges of the sealing flap are folded over so that the outer film layer is sealed on itself.
French Patent No. 1, filed on January 22, 1962, with Mrs. T (formerly G*rahain@Mallard) as the inventor.
No. 331,100 shows a package with a hermetic seal where the open edges of the series are folded outward and heat sealed across the four film layers. April 1972
H, E published on the 11th of the month.

3tanl@y and QoM, T@kjs U.S. Pat. No. 4,645,505 discloses that multiple layers of films are sealed together and when the package is peeled to open the outer layer of one film ruptures the seal. The hermetic seal of the package is shown tearing only in the area.

Another object of the present invention is to provide a package and seal configuration that provides improvements over these and other currently available structures.

Another problem encountered in packaging for cheese, luncheon meats, etc. is that often only a portion of the product is consumed at a time, and the package cannot be effectively resealed to protect the remaining product. This is desirable. In the conventional technology, November 20, 1979
U.S. Patent No. 4,174,597 to Movll et al.
No. 4.13a, Mowli et al., issued February 13, 1979. No. 32, U.S. Pat. No. 4,124,085 to Movli et al., issued November 21, 1978;
A number of resealing means have been proposed, including those disclosed in Moull et al., U.S. Pat. In other words, once it is bent or folded, it maintains its shape and does not attempt to spring back to its original shape.
(twist ti・) member is used.

The above aspects are achieved by the present invention, which will be better understood upon reference to the following detailed description of the invention.

According to one aspect of the present invention, there is provided a method of manufacturing an easy-to-open package having an integral folding member, which comprises the following steps. That is, ←) providing a side-sealed bag formed from a highly flexible 712 thermoplastic film material, said film having at least two layers, said bag having an open end and a closed end; (e) removing a corner of said bag adjacent said end opening so that two extending lip portions are formed; attaching a band-shaped folded state holding member to the folded state holding member, and (d) wrap and surround the folded state holding member within the fold of the lip portion to which the folded state holding member is attached. folding into the end opening, and the folding brings parts of the outer surface of the bag into direct contact. within each fold thereof and closing the bag, the heat seal being disposed across the width of the bag between the fold line and the edge of the inwardly folded lip portion; (f) peeling off the fold to provide a grippable tab for opening the bag; and (f) placing the bag in the product prior to applying the heat seal in the process. According to another aspect, the present invention provides a reclosable feature comprising: It provides a package with

(1) a bag constructed from a multilayer thermoplastic packaging film, said film having at least two layers, said bag having a closed end and an open end; (b) said bag having a closed end and an open end; (e) the product in the bag; d) a transverse heat seal across the width of the bag, the seal being located between the fold line and the edge of the folded lower lip, each portion of the outer surface being sealed together by the seal, the fold providing a graspable tab that can be peeled to open the bag; consisting of a band-shaped folded state retaining member disposed inside one of the folds and rubbed by it, so that the bag can be closed by folding the folded state retaining member after being opened; O Next, a specific example of the present invention will be described with reference to the drawings.

First, in FIG. 2, a product 6, which may be cheese, luncheon meat, etc., is shown sealed by a multilayer film F. The pouch formed from the multilayer film F can be formed in several different ways and can be referred to as a bag, sachet, package, etc. In the preferred embodiment, a seamless tube of three layers of film F is closed at one end by an end seal 15 forming the bottom of bag B. This bag part is filled with the product 6 and, in order to close the filled bag part, an inward fold is formed at its open end along line 12, in this case when the bag opening is flattened. Edges E1 and XX are folded downwardly so that they engage or mate. In the flattened state, heat sealing is performed by compressing the four layers of material in the sealing area A. All surfaces in contact in the seal area will be sealed to each other. This configuration allows for a separation mechanism that can be grasped by human fingers to peel off the seal.
Possible tabs 4.5 remain. When this peeling occurs, the rupture (rwptme) as well as the cleavage (d@lamination) shown in FIG. 1 occurs.

In FIG. 1, sealing area A indicates the seal that actually closes the opening to the bag R. In FIG.

This seal is indicated by seal S in FIGS. 1 and 2. When the tab 4.5 is grasped between human fingers and pulled off, a rupture occurs at the beginning of the seal S in the sealing zone, as shown in FIG. The cleavage between continues to the edge E of the film,
As a result, at this time, the multilayer film F' of the opening 20Fi tab 4
-1 through the torn outer layer 3 and through the tear between layer 5 and its adjacent layer 2 continuing to the edge of the film E;
You can access the inside of the bag. The product 6 can be removed from this opening and reinserted into the bag.
In the figure it can be seen that the film F from which the bag is formed is a three layer film comprising an inner layer, an intermediate or adjacent layer 2 and an outer layer 3 (in figure 2 the outer layer 5 is outside the bag O). A preferred five layer film is disclosed in U.S. Pat. No. 4,271,738 to H. J. Brax et al., issued July 14, 1981. When the Brax film described above is matched to each layer in FIG. 1, inner layer 1 is a radiographically crosslinked ethylene vinyl acetate copolymer having a thickness of approximately 038 mm (tS mils). ; middle layer 2 is about r
The outer layer 3 is a cross-linked ethylene vinyl acetate copolymer having a thickness of approximately [LO18 (α7 mils)]. be. The vinyl acetate component in the ethylene vinyl acetate copolymer is a mixture of a suspension polymerized copolymer of 10 and an emulsion polymerized copolymer of about 10 to. It is a copolymer of vinyl chloride and vinyl chloride.This emulsion polymerized copolymer consists of about 70% vinyl chloride and about 30% vinyl chloride, and is a suspension polymerized copolymer. It consists of approximately 80 liters of vinyl chloride and 17 liters of vinyl chloride.

Using the above-described film, which is manipulable in a seamless tube, so that the end seal 16 closes the bottom of the bag,
When folded into the configuration shown in FIG. 2, the top of the bag lays flat and assumes the appearance shown in FIG. In this position, the heat seal can be applied over a large area of the bag. The contents of this seal are approximately 52 to &
4■ (1 to - inch), New York, USA 4
8. The sealing device may be applied by a sealing device such as a Plutzklin V@rtrod company or other heat sealing device as is well known in the art. A pressure of about 12 K47 on is preferred and the sealing device is set so that the temperature at the interface where sealing occurs is within the range of about 107-148°C (225-500?).

In laboratory equipment, the total sealing time consists of approximately α6 seconds for preheating of the sealing bar, 15 seconds for heat welding time when said pressure is applied to sealing area A, and release. Because of the time, it is approximately α1 second.

In industrial operation, the seal parr requires no cooling time, and the preheat time is approximately α1 seconds, resulting in a total penetration time of approximately 1 second.
It will be 5 seconds.

Although the seal created by the method described above maintains the integrity of the package and withstands rough handling, this seal
It can be easily opened by grasping the tabs 4 and 5 shown in the figure and pulling them in opposite directions.
The outer layer 301 as shown breaks and cleaves to edge 1-1 or E-2 of the film. It is observed that this cleavage condition occurs without causing rupture of the outer layer 3.

A reclosable feature is provided, which may be a "twist-knot" strip or wire or other material with folded retention properties. The strip 7 is placed inside one of the end folds as shown in the cross-sectional view of FIG. 2 or the plan view of FIG. The strip 7 capable of retaining the folded state can be obtained by simply punching a hole 'K' as shown by the dotted line 21 in FIG. 2 and inserting the strip 7 capable of retaining the folded state into the hole. After the bag has been opened, the bag material is rolled up in region 23, similar to rolling up the end of a used toothpaste tube, and the retentive strip is then crimped or folded to form film material 25. Can be easily closed by fixing the roll.

Another method for performing the reclosure feature is shown in FIGS. 4 and 5. In FIG. 4, a side-sealed bag portion is shown formed by folding the film in the middle and sealing it along its sides with a heat seal 26. At the open end of the bag, the corners are removed by cutting along dotted lines 27. When the corners are removed, two opposing lips are formed which can be easily folded inwards. When the upper lip is bent,
The folding retention strip 7 with adhesive surface is placed on the upper side of the lower lip and fixed thereto, after which the lower lip is folded inwards. At this time, the bag is shaped as shown in FIG. 5 by aligning the lip edge Et with the inside of the notch. L, IJ tube is folded along fold line 12) (The tube is now ready to be filled with product, and once filled, a transverse heat seal is applied in area A;
In region A, parts of the outer bottom of the bag are sealed against themselves to close and seal the bag. A portion of the film is removed at 24 by punching or cutting. Removal of some of these film pieces attempts to reduce the stress on the side seal when the package is opened by pulling the fold tabs and directing the stress into the seal area. It has a tendency.

Other materials which may be suitably used in the present invention are copolymers of polyethylene and ethylene vinyl acetate, generally as materials for the outer layer, and nylon, vinylidene chloride copolymers, as materials for the adjacent layer.
It can be selected from the group consisting of homopolymers and copolymers of propylene, and copolymers of crosslinked polyethylene and ethylene vinyl acetate. The main criterion is that the tensile or breaking strength of the outer layer is greater than the bonding force between layers 2 and 5. Similarly, the bonding force between layers 2 and 5 must be less than the rupture strength, fill, or tensile strength of the adjacent layer 2 or the combination of layers 1 and 2 so that folding seals the outer layer 5 in face-to-face relationship with itself and thus ruptures. Other folding configurations are possible within the scope of the present invention, so long as the tear occurs close to or adjacent the edges of the film, providing an opening accessing the inside of the package.

[Brief explanation of the drawing]

FIG. 1 is an exaggerated view showing the sealing area showing the breakage of one outer layer and its rupture 11A from the adjacent layer; FIG.
The figure is an exaggerated sectional view showing one embodiment of the package of the present invention, FIG. 3 is a plan view showing the embodiment shown in FIG. 2, and FIG.
9 a plan view showing the bag in a flattened state before the condition-retaining means and the final seal are applied; and
The figure is a plan view showing a flattened bag ready to receive product prior to final pricking. 1...Inner layer, 2...Middle (adjacent) layer, 3...Outer@l-14, 5-...-tab, 6. −・・Product, 7・−・
Folded state retaining strip, 12... line, 13, one end seal, 20... opening, 21, 27... dotted line, 26
...Heat sealing part, F...Multilayer film, A...Sealing area, R...Bag, E...Edge, S...Cool @ Patent applicant Dabriny Fist R Fist Grace ψ and company ring

Claims (1)

[Scope of Claims] t. A method of forming an easy-to-open package having an integral folded state retaining member, comprising: (1) a side-sealed bag formed from a highly flexible thermoplastic film material; (b) the film has at least two layers, the bag has an open end and a closed end, and (b) the end opening is configured to form two extending lip portions. (e) attaching a band-shaped folded state retaining member to the inner surface of at least one of the extending lip portions, (the folded state retaining member being attached); said extending lip portion is folded into said end opening so as to encircle and surround a folded retention member within the fold of said lip portion, bringing portions of said folded bag exterior surface into direct contact; (-) flattening and heat sealing the folded lip portion to enclose the folded retaining member within each fold thereof and to close the bag; a fold over the entire length of the bag, a fold disposed between the line and the edge of the inwardly folded lip portion, the fold being adapted to peel off the fold to uncover the bag; and (f) filling the bag with product prior to performing heat sealing in step (1), thereby opening the bag with a reclosable collapsible retention member. 2. The method of claim 1, wherein the outer layer of the film is polyethylene at the fold line adjacent to the side seal. In an easy-to-open package with reclosable features, comprising: (a) a bag formed from a multilayer film comprising a thermoplastic t-shirt for packaging, said film having at least two layers; has a closed end and an open end; (b) inward folding of the lip portion of the opening of said bag, said folding being such that portions of said outer surface of said bag are in direct contact relationship; (e) a transverse heat seal across the product within the bag, the seal being aligned with the fold line and the edge of the folded lip portion; each part of the outer surface is sealed together by the sealing part, and the folding part provides a graspable tag that can be peeled off to cover the bag; and (e) a folded state retaining member disposed inside one of the folding portions along approximately half of the opening and surrounded by the folded state retaining member, so that the bag is opened after the bag is opened. The package is characterized in that the bag is closed by folding the folded state retaining member. 5. A package according to claim 4, characterized in that said bag is a side-sealed bag having corners removed from its open end.