JPS6241022A - Seal package and manufacture thereof - 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]! LL! 1. The present invention relates to a leak-proof sealed package for food products, a method for manufacturing the same, and a container. More specifically, the present invention is directed to folds (s) formed by manual packaging, semi-automatic packaging machines, or automatic packaging machines.
eam) or by sealing the folds and sealing and adhering the film to the bottom of the container with an adhesive seal to prevent leakage of liquids, e.g. juices from red meat or poultry meat. Regarding.

BACKGROUND OF THE INVENTION Fresh moist foods such as red meat, poultry and produce have long been packaged in some type of tray-type container or support and overwrapped with a flexible packaging film. The most commonly used packaging film is thin plasticized Pv
It is C. Once the individual packages were wrapped by hand or with semi-automatic or automatic packaging equipment, a sealing device was used to seal the film to seal the package and prevent leakage. In this way, the overwrap film is always
Moreover, it was difficult to fuse and seal with high reliability. In other words, the seal on the package becomes loose and damp, making it look unsightly inside the display case. Juices from red meat and poultry will probably leak into display cases and onto the hands and clothing of consumers who touch the packaging. Equipment manufacturers have not been able to successfully solve this problem. A melt seal can be achieved. However, it is common to create varying degrees of pseudo-"sticky" seals that appear fused but eventually separate under moist and refrigerated conditions. Central processors subject packages to harsher handling and transportation conditions than retail handling.

They are looking for leak-proof seals. It is an object of the present invention to provide such a leak-tight package.

SUMMARY OF THE INVENTION In a principal aspect, the present invention provides a method of adhesively sealing a film to the bottom of a container.

In another aspect, the present invention provides a method of achieving a positive seal between a tray or container and a film using conventional packaging equipment or in manual packaging. The invention thus enables a positive seal to be achieved on packages of meat, poultry, etc.

Description of the Invention and Best Mode The present invention includes 1. Any packaging film can be used, preferably a heat-sealable film, but in the preferred embodiment B of the invention transparent flexible films that meet government regulations for food contact, such as the well-known PvC film, can be used. or other polyolefin films. These packaging films are well known and widely available from numerous commercial suppliers. , a specific concrete example of a satisfactory film is
Polyvinyl chloride (PVC), polyvinylidene chloride (Saran), ethylene/ Made and available as films of vinyl acetate copolymer (EVA), polyethylene, polypropylene and flexible butadiene/styrene copolymer (SBR) in thicknesses from about 0.3 to about 10 mils, preferably from 0.5 to 1 .5 mil packaging film. Polyester films, such as PET films, are also commercially available and used for this purpose.

Board (BOA) useful in making the package of the present invention
rds) or containers or trays are likewise well known and readily available commercially. These fall into three board categories. namely cellulosic material board, foam material board and hard plastic board. Generally, the first two are referred to as paperboard composition trays or foam composite trays. Fiberboard trays or containers are widely used for wet meats such as balk or chicken.

Styrene foam trays can be used with paper permeable mats or pads that absorb liquid.

According to current commercial usage, these trays or boards are generally rectangular, have upwardly extending side walls, and are supplied in packages stacked on top of each other.

Each individual tray or container is removed from the package, filled with red meat or related foods such as beef, balk, chicken, fish, and then wrapped with a suitable film fed from a supply roll. The overwrapping area or crease area of the package is then located below the container bottom. In that case, Taitong's method involves placing the wrapped package on a belt sealing device or other packaging device for wrapping and sealing. This folded film is sealed in so-called pockets of the side folds, which vary from 2 to 5 layers. In current practice, the locations where leakage occurs under stress and handling operations are generally the so-called pockets. At these 3 to 5 layers, some of the cooling, labeling, cartoning, and bulk shipping are performed together with intensive processing.
Puts more stress on the package.・The inventor has developed not only the first layer, but also the so-called pocket 3~
It has been discovered that a positive seal can be achieved with the bottom of the tray even with five layers and more. This seal is achieved by applying a coat or seal of adhesive along a peripheral or rectangular area of the bottom of the tray or container, then
In one embodiment, the sealing is accomplished by carrying out conventional packaging methods in which the seal is achieved by an adhesive cover layer or seam adhesive between the bottom of the container and the film with the heat of a conventional belt-type heat sealing device. . Normal package weight W
is heavy enough to cause sealing, but additional pressure may be applied, from as little as less than 1 bond per square inch to about 8 to 10 psi to provide a satisfactory seal. It is enough. Similarly, the temperature of use, depending on the adhesive, film, and tray, must be sufficient to seal the film in the equipment used.

Some equipment uses temperatures up to 190-198°C and requires sealing times of about 1-5 seconds.

Alternatively, the package can be sealed with hot air from a blow gun or similar hot air means.

Adhesives useful in the present invention are well known and readily available for adhering films and include the well known groups of water emulsion adhesives, solvent based adhesives and hot melt adhesives. These adhesives are based on well-known polymers and copolymers, such as butadiene/styrene copolymers, polyisoprenes, block diene polymers or copolymers, natural rubber, polyvinyl acetate, polyesters, polyethylene/acetic acid. Made using vinyl, natural or hydrocarbon waxes, resins and wood resins. Useful in the present invention as specific representatives of these groups,
To name a few representative products that meet government standards for food use, we would like to mention wing tack.
(14inOtaCk”) 95g/L/C3
Plioflex” latex, Wingtack H10 emulsion or Wingtack THG-5 adhesive known as polyterpene or hot melt adhesive VPE10035 or VPE
There is 4709.

The nature of the invention can be more easily understood with reference to the drawings.

Referring to FIG. 1, numeral 10 represents a polystyrene foam, paper mat or transparent plastic tray, and 11 represents a chicken or related poultry product placed on the tray. Tray 10 and poultry product 11 are packaged so that the bottom 12 of the tray rests on a sheet 13 of film. Sheet 13 is folded down to the number 1
5. with edge 14 shown in relation to the various edges of the film giving layers designated 16 and 17. These folded edges are then heat sealed by applying pressure and heat to activate the adhesive 18 and adhere the layers of film to each other and to the tray.

In FIG. 2, the seam of adhesive 18 is located at the bottom 12 of the tray.
is shown applied essentially all the way around the periphery of the . Alternatively, the width of the periphery may be increased until the adhesive fills the entire area indicated by the number 20.

In some embodiments, the tray bottom has a thickness of about 0.1 to 5 mils, preferably 0.3 mils, covering all or most of the surface.
It is more convenient to use a sheet of ~1.5 mil adhesive. This is a particularly desirable option when using hot melt adhesives.

Another option is to apply the adhesive to the bottom of the tray by spraying or doctor knife, or any other method commonly used to apply adhesive to the bottom.

The nature of the invention is better illustrated and explained in the following illustrative representative examples. Parts and percentages herein are by weight unless otherwise stated.

Example 1 A polystyrene poultry tray was filled with shredded chicken or bokeh products. It will be appreciated that tray manufacturers can apply adhesive to the trays during the manufacture of the trays and therefore sell trays to packagers that have the bottoms pre-applied with adhesive. Prior to use, coat each tray with a water-based emulsion adhesive, TH P1iobond 7005.
”) spraying, doctoring and print rolling (1) rint rolling)
The adhesive coat was then dried to provide a clear, non-tacky coating on the tray. The trays containing the dried adhesive and meat are then coated with plasticized PvCTH to a thickness of 100 gauge in the usual manner.

Vitawrap (V+tawrap) is a food film.
”).This package was wrapped by an automatic packaging machine.
TH Weldotron” A-12:
1 and heat sealed at about 195° C. and less than 1 bond pressure for about 1 to 3 seconds. Separately, another package was sealed with hot air from a blow gun. The resulting sealed packages were stored in freezers and other handling areas and no leakage of meat juices was observed as experienced with packages sealed without an adhesive coat.

The VitaLap TH film described above can be replaced by a polyester film or other commercially available packaging film with which a good seal is achieved with the present invention. Polyester type hot melt adhesives are particularly desirable for polyester films and can be applied as a seam or coat to the bottom of the tray.

Example 2 In one embodiment, a sheet of hot melt adhesive about 0.1-5 mils thick, preferably about 0.3-1.5 mils, is placed between the bottom of the tray and the film and then heat sealed. We obtained a satisfactory leak-proof package. These hot melt adhesive sheets can be obtained by any of the known sheet manufacturing techniques, such as extruding, casting, or doctoring the hot melt adhesive onto a surface suitable for sheet formation.

As those skilled in the packaging art will readily appreciate, certain adhesives are used with certain packaging film trays. For example, solution-based adhesives that have good solubility in styrene in their solvents cannot be used on styrene trays, whereas solution-based adhesives that use paraffinic hydrocarbons, THE, and lower alcohols have good solubility in styrene. No or small adhesives are used with styrene trays.

Similarly, PVC films, Saran films, and related films are known to be affected by solvents such as ketones and THE, so these solution based adhesives are not preferred for these films. When using a polyethylene film, it is desirable to subject the surface to a corona treatment to improve the adhesion of the adhesive to the film. Emulsion type adhesives are generally preferred for use with trays and films. Thus, one skilled in the art can select trays, films and adhesives to avoid the drawbacks mentioned above and to meet government standards for the products being packaged.

According to the invention, there is provided a container made of cellulosic or styrenic foam having a shape such that an essentially three-dimensional meat and related food product is visible as the top and sides of the package; is visible, because the sides of the bottom of the tray are relatively low (usually 2.5 cm
1 m), to give a flat tray appearance or a flat board appearance, relatively speaking, to give the container the appearance of a thick board as one perspective view.

Some people say that the bottom of the meat tray should also be transparent or see-through so that the meat can be seen from all sides. Such see-through trays are generally made from clear plastic, but cannot contain paper permeable mats that absorb meat juices. Also, since these transparent trays are generally more flexible and deform more in semi-automatic and automatic packaging equipment, it is more difficult to achieve a satisfactory seal on plastic trays, and therefore these packages are often described as messy. becomes.

Example 3 A series of transparent plastic trays made from rigid polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene were each coated with a water emulsion of ethylene/vinyl acetate adhesive along the entire bottom surface to a thickness of approximately 0.5 mm.
Application 1 was applied to give a clear dry coating of 5-1 mil.

Fill each tray with wet meat, then feed the trays through the packaging machine Weldtron A + 12” and transfer to Gotafilm 1H.
The result is a package that is leak-proof and allows the meat to be seen from all sides.

For solid plastic transparent trays, the adhesive must provide a transparent coating within the thickness range used, but even then the package may be in salable condition and may be of no practical use. Some exhibit conditions.

Transparent hot melt adhesives, namely VPE 10035 or PE 4709, can be used to coat the bottom of such transparent plastic trays and can be used to obtain satisfactory transparent, leak-proof packaging packages. .

The most preferred adhesives for use in the present invention are those that form a cohesive failure adhesive bond between the film and the tray. Although minimal bond strength is not essential as long as the film-to-tray bond remains liquid-tight, peel testing after 1 inch (2,540) about 0.5-5psi, more preferably 1-3p
It is preferable that a bond strength of si is obtained. Furthermore, the adhesive must be selected so that it is not adversely affected by liquids or liquids present in the food product.

Although typical embodiments and various parts have been shown above to illustrate the present invention, those skilled in the art will be able to make various changes and modifications to the present invention without departing from the spirit and scope of the invention. That should be obvious.

[Brief explanation of drawings]

FIG. 1 is a side view of a package of the invention, and FIG. 2 is a bottom view of a tray of one embodiment of the invention, with adhesive applied to the peripheral seam area rather than the entire bottom surface. Give an example. 10... Tray 11... Meat 12... Tray bottom 13... Film sheet 14...
Film end 15.16.17...Film layer 1
8...Adhesive 20...Full bottom FIG, 1

Claims (23)

[Claims] (1) (a) a container having a bottom, the container having an adhesive on at least the periphery of the bottom; (b) food contained in the container; and (c) a container having a thickness of about 0.3 mil or less. an approximately 10 mil polymeric material film sealed to the bottom of the container with the adhesive to form a liquid-tight package of the film over and surrounding the container; A seal package useful for packaging food products. (2) The package according to claim 1, wherein the film is heat-shrinkable. (3) The package according to claim 1, wherein the film is made of plasticized polyvinyl chloride. (4) A package according to claim 1, wherein the adhesive is applied as a water emulsion. (5) The package according to claim 1, wherein the adhesive is a hot melt adhesive. (6) applying an adhesive coating or seam around at least the bottom side edge of the container; placing the food product in the container; and leaving a fold formed in the packaging film below the bottom of the container; wrapping the container with the film and subjecting the film to sufficient heat and/or pressure to form a seal between the film layers and between the adhesive applied to the bottom of the container and the film. A method for forming a leak-proof sealed package characterized by: (7) The method according to claim 6, wherein the container is a composite material of cellulosic material. (8) The method according to claim 6, wherein the container is made of polystyrene. (9) The method according to claim 6, wherein the film is made of polyester. (10) The method according to claim 6, wherein the adhesive is a hot melt adhesive. (11) The method of claim 6, wherein the adhesive is an ethylene/vinyl acetate copolymer-based hot melt adhesive. 12. The method of claim 6, wherein the adhesive is applied as a water emulsion of ethylene/vinyl acetate copolymer. 13. The method of claim 6, wherein the adhesive is applied as a water emulsion of natural rubber or butadiene/styrene copolymer. 14. The method of claim 6, wherein the adhesive is applied as a coating or seam having a thickness of at least 0.1 mil. 15. The method of claim 6, wherein the adhesive is placed between the bottom of the container and the film as an adhesive sheet having a thickness of 0.3 mils to 1.5 mils. (16) A method according to claim 6, wherein the heat is applied with a jet of hot air. 17. The method of claim 6, wherein the adhesive is applied essentially at the same time as forming the tray. (18) Red meat characterized by consisting of a mat or board shaped so that the red meat or food is visible, having a bottom that supports the red meat or food and having a coating layer of adhesive on the bottom. and food packaging containers. 19. The container of claim 18, wherein the sidewall extends upwardly to a height of less than about 2.5 cm to give the container the appearance of a tray. (20) The container according to claim 18, wherein the mat or board is made of styrene foam. (21) The container according to claim 18, wherein the mat or board is made of cellulose material. (22) The mat or board is of shaped transparent solid plastic having a transparent adhesive applied to the bottom surface of the mat or board to provide a see-through bottom. The container according to item 18. (23) A container according to claim 22, wherein the transparent solid plastic is selected from the group consisting of polystyrene, polyester, and rigid polyvinyl chloride.