JPH0999975A - Easily openable package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a more easily unsealing means than the well-known means at present or the means obtainable in the market when holding a web to be peeled off and unsealing a package, in which an end user can easily know the position to begin to peel off the package web. SOLUTION: This package is an easily unsealing package hermetically sealed between an lower thermoplastic web provided with an opening 1 and a rim 4 formed at the periphery of the opening and an upper thermoplastic web 7 superposed on the lower web and sealed by the lower web in the seal part including the peripheral edge rim 4. The lower thermoplastic web is provided with at least one recess 6 at the end of the peripheral edge rim 4. A non-contact part 8 where the package is unsealed by picking up it, is provided in the upper web.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an article, generally a food product, which is confined between two webs of thermoplastic material and which is not damaged or stored during storage, shipping and display of the product packaged therein. It relates to an easy-to-open package in which the package is hermetically sealed to protect against contamination and yet can be easily opened manually by the end consumer without the use of knives, scissors or other tools.

[0002]

BACKGROUND OF THE INVENTION A wide variety of products, especially food products, are provided in a visually appealing package consisting of two thermoplastic webs superposed, a lower web or a lower web and an upper web or an upper web. However, these webs are formed by a variety of methods such as thermoforming, vacuum skin packaging, and others that can generally be considered as variations on these two conventional methods.

In these methods, the lower support web is
It preferably has a tray-like shape forming a container for containing the articles to be packaged, having one opening and a rim formed at the periphery of this opening. This tray-like shape is generally formed in-line or off-line by a thermoforming process.

In the thermoforming process, the upper web is placed on a container containing the articles to be packaged, the chamber containing the lower and upper webs is evacuated, and the upper web is heat sealed, usually in the form of a sealed frame. A stop platen seals to the peripheral rim of the thermoformed lower web. If an atmospheric package is desired, an appropriately selected gas mixture is injected into the chamber between vacuum and sealing.

In a vacuum skin packaging process, the top web is generally drawn into a recessed cavity formed in a vertically movable thermoforming platen and the top web is contacted by suction to the heated ceiling and walls of the cavity. Heat while maintaining the condition. The vacuum packaging chamber is then evacuated and the suction applied to the cavity wall of the mold plate is stopped, pulling the upper web downward and contacting the product contour and the lower web. The upper web thus forms a hermetically sealed skin around the entire circumference of the product and is adhered to the lower web by the pressure difference and seals when the two webs come into contact with each other. Depending on the temperature and the material used for the top web, a heat seal frame can also be used to more tightly seal the top web to the peripheral rim of the bottom web.

[0006] The above-mentioned package requires heat sealing of sufficient strength to maintain the integrity of the package during distribution and storage, and the final consumer opens the package with normal human power. It must be balanced with the need for a heat seal that can be easily opened.

In order to reach the desired compromise, several methods have been devised which also involve the proper selection and combination of materials.

These methods essentially consist of an easily peelable seal layer, which is one of the two layers which are in contact with the seal layer in a sealed package under normal force. Based on the concept of having a peeling seal layer, or if a tearing force is applied from the outside, the necessary adhesive force in the seal layer is eliminated and the package can be opened or the seal layer made of different materials It is based on the concept of having one layer adjacent to the sealing layer.

In the present invention, the term "easy-to-open package" refers to the complete tearing of the packaging material by proper selection of the composition of the top and bottom webs, especially the sealing layer and its adjacent layers. Alternatively, it refers to a package that can be easily opened without breaking, more specifically, a heat-sealed and bonded region of such a package.

In any case, no matter what easy opening mechanism is used, the package is opened by a convenient means of peeling the package, ie, where the end consumer begins peeling the two thermoplastic sheets. Need to be even easier.

British Patent No. B-1360808 is formed from webs that are laminated and sealed of thermoplastics, with a paper sandwiched between the webs to prevent localized sealing and to be easily opened from the corners of the package. Disclosed packages.

British Patent B-1510115 was also formed from a web of thermoplastic material laminated and sealed to allow easy opening from the corners with a patch of ink that prevented the two webs from adhering to each other. Discloses the package.

Canadian Patent No. B-1164260 describes a package in which the corners of the lower web are bent downward by a punching device with the upper web having no surface to be bonded during the sealing step.

Vacuum skin packaging machines are commercially available that pre-cut the corners of the lower web and then bond it to the upper web. To open the package, first bend the pre-cut corners upward or downward along the cut parts, or in both directions.
It must be peeled off from the rest of the bottom web.

However, even with these methods, it is often difficult to open the package. It is not easy for the consumer to know where to start opening the package, and even in the non-adhesive areas the two webs tend to stick to each other and thus the two thermoplastic webs at the corners. Because it cannot be separated. Furthermore, in the case of pre-cut corners, the corners cannot always be easily peeled from the rest of the tray, and bending the corners downwards does not allow the top web to be peeled off first and damages the top web. There are also things to do.

[0016]

In view of the aforementioned technical problems, the main object of the present invention is to make it easy for the end consumer to know where to start peeling the package web, grab the web to be peeled and open the package. Is to eliminate the aforementioned drawbacks by providing a package which is easier to open than currently known or commercially available means.

Another object of the present invention is to provide an easy-to-open package with a means for peeling the packaged article, which has enhanced display and cosmetically appealing characteristics of the packaged product.

Another object of the present invention is a method for manufacturing the package which is easy to open and an apparatus for carrying out this method.

[0019]

SUMMARY OF THE INVENTION These and other objects include an article wherein an article has a lower thermoplastic web having an opening and a rim formed at a periphery of the opening, and the article overlaps the lower web at the peripheral rim. An easy-to-open package sealed between an upper thermoplastic web and a lower thermoplastic web having at least one recess at the end of the peripheral rim to initiate opening of the package. This is accomplished by the present invention, which provides a package that is easy to open for the first purpose with a finger-grabbable non-adhesive portion in the top web.

In a preferred embodiment, the easy-open package is realized by a vacuum skin packaging method.

In a second embodiment, the present invention is a method for manufacturing an easy-to-open package comprising means for peeling a package according to the invention, wherein a lower web and an upper web that overlap in the sealing area are bonded together. Providing an easy-open package that can be closed by forming a recess in the sealing portion of the lower web at the end, and sealing the lower and upper webs at the sealing portion, thereby It relates to a manufacturing method, which comprises providing a non-adhesive part which can be gripped with a finger to start opening a package in a web.

Other features and advantages of the present invention can be obtained by reading the following description of preferred, non-limiting embodiments of the easy-open package of the present invention, with reference to the accompanying drawings.
It will be understood more clearly.

[0023]

1 and 2, the lower web has a substantially tray-like shape and has an opening 1 and a bottom 2 for which the bottom is generally It has a wall 3 that extends opposite to and a peripheral rim 4 around the entire circumference of the opening. The bottom may have a corrugated surface forming a plurality of passageways or microchannels that intersect one another to facilitate air evacuation during the sealing operation. Additional passages
It is formed by a groove 5 which extends substantially parallel to each other towards the bottom so as to communicate with said microchannels and to facilitate the evacuation of air. 6 recesses in the lower web
Is formed. Thus, the upper web 7, which overlaps the thermoformed lower web and is sealed to the lower web at the sealing portion including the peripheral rim, has a non-adhesive portion 8 which communicates with the recess formed in the lower web. This non-adhesive part 8
You can easily grab it with your fingers and tear it apart. Especially in the case of vacuum skin packages where the top web is transparent, the point where the opening begins is readily apparent and there is no need for the end consumer to print or mark arrows or indicia on the web for proper instruction. The dimensions of the recess and thus the non-bonded portion of the top web can vary depending on the dimensions of the package and the peripheral rim, provided that they are easily grasped by the normal human hand. .
Generally, a package having a width of about 8 cm to about 20 cm and a length of about 15 cm to about 30 cm has a rim width of about 1 cm to about 3 c.
Manufactured in m. As an example for the half-moon or lunette-shaped recess shown in FIGS. 1 and 2, depending on the width of the rim, at least about 0.7 cm, preferably at least about 0.8 cm, more preferably at least about 0.9 cm.
A radius of ~ 2.5 cm, or greater, may be suitable.
The shape of the recess is not critical provided that the non-bonded part of the top web can be easily gripped. Therefore, a circular or oval recess is preferable because it fits well on the fingertip.
The recess is preferably centered on the tray side to better balance the opening force applied and to tear the top web more uniformly. However, this is not absolutely necessary and the recess may be in an asymmetric position on the lower web side.

As pointed out above in the preferred embodiment of the invention, an easy-open package is obtained by the vacuum skin packaging method, and in a further preferred embodiment, thermoforming of the lower web is well known in the art. In-line by any suitable technique of. However, a preformed tray provided with suitable recesses by known means can be used in the packaging method according to the present invention.
Easy to understand.

In the most preferred embodiment of the vacuum skin packaging method of thermoforming the lower web in-line, shown schematically in FIG. 3, the manufacturing apparatus includes a first reel 10 on which a lower web is placed. A web of material 11 is wound and a first reel is rotatably supported on a pedestal 12. Attached to the pedestal is a thermoforming section 13, which generally includes a heater element 14 facing the mold element 15, in which the lower web is thermoformed into a tray-like shape of suitable shape and size. It Suitable thermoforming methods include, for example, vacuum forming or plug assisted vacuum forming methods. In the vacuum forming process, the lower web is heated, for example by a contact heater or infrared, to create a vacuum under the web, which forces the web into a preformed mold by atmospheric pressure. Alternatively, after heating the lower web, atmospheric pressure is applied to the web to force the web into the preformed mold by the applied pressure. In the plug-assisted vacuum forming method, after the web is heated and sealed across the mold cavity, a plug shape similar to the shape of the mold strikes the web and a vacuum is applied to move the lower web to the surface of the mold.

The recesses are preferably formed in the lower web after thermoforming. In such a case, downstream of the thermoforming section, the device comprises means 16 for forming a recess, which is shown in detail in FIG.
Having. This can be done, for example, by means of a punching machine which comprises a stamping mold perforation and a master formed in the desired shape, which machine lowers and punches out holes and rises again when a recess is formed. Alternatively, the recess can be formed by other means including, for example, a blade, a knife or a punching device with a laser treatment device. To prevent the package contents from being contaminated with plastic pieces,
Punched or cut pieces of thermoplastic material are preferably removed, for example by suction of a piercing device. Even if the recess is formed after thermoforming in a preferred embodiment of the process according to the invention, the thick lower web will not be deformed in the subsequent thermoforming process, so that when the thick lower web is used, You may form a recessed part before. In this case the means 16 should be placed upstream of the thermoforming section.

The device has a portion 17 for manually or automatically dispensing the product to be packaged into the tray.

Downstream of the loading section, the device has a package section 18 which rotatably supports a second reel 19 around which an upper web 20 is wound.

The tray loaded in the package part is evacuated and, for example, British Patents A-1307054, A-1206023, and Belgian A-988216.
No., European Patents A-93480 and A-2702.
The top web is sealed by a conventional vacuum skin packaging method as described in No. 08.

In practice, the width of the lower web is several (usually 2 to
The width is such that four (typically three) trays can be formed in parallel with each other, so that a plurality of sealed packages can be separated from the package portion 18 by a plurality of parallel packages as shown in FIG. The package is output in the form of a continuous web.
Therefore, next to the packaging part 18 is a cutting means 21, which cuts the sealed packages in the packaging device into individual packages.

FIG. 5 is a detailed view of the means for forming the recess according to the preferred embodiment of the present invention. Perforated punch mold 2
There are three 2s in the 3-lane thermoformer, which are located downstream of the thermoformer 13, below the platform 12, and in the center of each lane. These are automatically manipulated to raise and punch the web into the corresponding suitable mold 23 in the area corresponding to the peripheral rim of the end tray, thus ensuring that the shape and size of each tray is appropriately selected. At least one concave portion is formed.

In the preferred embodiment, the punching device creates a hole in a portion of the area between two successive thermoformed trays, thus providing the end of the packaging process to provide separate packages. The transverse cutting of the package web sealed in the above facilitates the opening of a package having a recess at the end of the peripheral ribs of the lower web, which has the size and shape of half the hole, said recess being shown in FIG. As shown
It is located behind one tray and thus in front of the next.

If such holes are provided in all non-thermoformed parts that fall between the thermoformed zones, the resulting package will have two recesses of similar shape on opposite short sides. Become.

The lower web used to produce the easy-open package according to the present invention preferably comprises a multi-laminate structure having flexible properties which vary depending on the end use. Semi-rigid gas barrier structures are generally preferred. Generally, these are polyvinyl chloride (P) containing a suitably selected sealant layer on the surface to be sealed to the top web.
Laminates based on VC) or polystyrene (PS). The thickness of the lower web is usually 100-450μ,
Generally, it is 150 to 300 μ. The top web may be, for example, a substrate of irradiated or non-irradiated non-oriented polyethylene, ionomers, polyesters, PVC, etc., or thermoformable materials, barrier layers, preferably ethylene vinyl alcohol copolymers, and appropriately selected sealant layers. You may make it the laminated body containing. Typical top web thicknesses used in vacuum skin packaging methods range from about 45 to about 250.
μ, preferably about 70 to about 180 μ. Suitable sealant layers for the lower and upper webs and their suitable combinations to provide an easy to open package are described, for example, in U.S. Pat. Nos. 4,382,513 and 4,466,513.
No. 0, A-4666778, A-5023121
, European Patent B-192131, and European Patent Application No. 93250270.1, the contents of which are incorporated herein by reference.

The following examples and comparative examples correspond to easy-to-open packages with means for peeling the package according to the invention, with conventional pre-cut corners glued to the upper web as means for initiating the opening. Show that it is much easier to open by hand than an easy-to-open package.

A comparative package according to the prior art is C
Made by vacuum skin packaging method using RYOVAC® VS44 machine. The machine is equipped with knives to precut the corners of each tray. The tray obtained in-line by thermoforming is 13 cm wide, 25 cm long and 1.2 cm deep. The width of the rim is 1.5 cm on the short side before and after the tray,
It is about 0.8 cm on the long side.

As the lower web, 75% EVA (12%
VA), 20% polybutene-1 and 5% polypropylene mixed with a semi-rigid polyvinyl chloride sheet (200 μ thick) with a contact surface layer (9 μ thick), the top web being the next layer: LDPE / tie layer / EVOH / tie layer / LDPE / ionomer, each of which has a partial thickness (μ) of 40/3/8/3/40/6 A flexible coextruded multilayer film irradiated to a dose of 12 Mrad, which represents a partial zinc salt).

The package according to the present invention has an improved CR.
Manufactured using a YOVAC® VS44 machine, in which the means for precutting the corners is eliminated and instead the means for forming two recesses in each tray are used, each recess being a short tray Located in the center of the side, these recesses are half-moon shaped with a radius of 1.1 cm.

The tray and tray rim sizes and the combination of top web and bottom web and mechanical conditions are the same.

A seal with the desired seal strength was obtained in two cases, but a statistically significant number of samples of the package according to the invention yielded eight samples compared to the same number of packages according to the prior art. Tested by the Commission, it was determined to be much easier to open than prior art packaging.

Similar improvements can be easily made to various packaging machines such as the MULTITIVAC CD6000 machine, and similar results are expected in terms of unsealing property.

Throughout this application, the shape of the thermoformed lower web has been described as being a conventionally used shape, rectangular. However, virtually any shape of overlapping webs can be provided with means for stripping the package according to the invention by forming a suitable recess in the lower web.

[Brief description of drawings]

FIG. 1 is a schematic top view of a package according to the present invention.

FIG. 2 is a perspective view of the same package.

FIG. 3 is an overall layout view of a packaging machine according to the present invention.

FIG. 4 is a detailed view of a continuous two-row package formed using the packaging machine according to the present invention.

FIG. 5 is a detailed view of a means for forming a recess in the packaging machine according to the present invention.

[Explanation of symbols]

 1 Opening 2 Bottom 3 Wall 4 Peripheral Rim 5 Groove 6 Recess 7 Upper Web 8 Non-Adhesive Area 10 First Reel 11 Lower Web Material 12 Units 13 Thermoforming Section 14 Heater Element 15 Mold Element 16 Means for Making Recess 17 Product Distributing part 18 Package part 19 Second reel 20 Upper web 21 Cutting means 22 Perforation punching mold 23 Mother mold

Claims (7)

[Claims] 1. An article comprises a lower thermoplastic web having an opening 1 and a rim 4 formed at the periphery of the opening, and a sealing portion of the lower web that overlaps the web and includes the peripheral rim. An easy-to-open package sealed between an upper thermoplastic web 7 and a lower thermoplastic web 7 having at least one recess 6 at the end of the peripheral rim.
An easy-to-open package characterized by having a non-adhesive region 8 in the top web, which has a non-adhesive region 8 which can be grasped with a finger to start opening the package. 2. The easy-open package according to claim 1, which is obtained by a vacuum skin packaging method. 3. The easy-open package of claim 1, wherein the lower thermoplastic web has a tray-like shape. 4. The package according to claim 3, wherein the center of the recess is on the tray side. 5. The package according to claim 1, wherein the recess has a lunet shape. 6. The easy-open package of claim 5, having a radius of at least about 0.7 cm, preferably at least about 0.8 cm, and more preferably at least about 0.9 cm. 7. A method for manufacturing an easy-to-open package comprising means for peeling a package according to claim 1, wherein the lower heat source has an opening and a rim formed at the periphery of the opening. Providing a sealable, easy-to-open package by bonding a plastic web and an upper thermoplastic web that overlaps the web and is sealed to the sealing portion of the lower web including the peripheral rim, the lower web Forming a recess at the end of the peripheral rim of the, and non-adhesive which allows the lower web and the upper web to be sealed together at a sealing portion so that they can be grasped with fingers and start opening the package. A method including providing a region 8 in the top web.