JP2561865Y2 - Vacuum packaging bag - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION Generally, the present invention relates to a method of stacking a pair of sheets having a heat seal layer laminated on an inner surface thereof.
The present invention relates to a vacuum packaging bag which is sealed by heat-sealing the periphery thereof, and particularly to a vacuum packaging bag which is suitably used for vacuum packaging an object to be liable to ooze moisture, such as ham and meat pieces.

[0002]

2. Description of the Related Art Conventionally, a vacuum packaging bag 2 shown in FIG. 1 is well known. The vacuum bag 2 is composed of two sheets, a first sheet (front sheet) 10 and a second sheet (back sheet) 16, and the outer peripheral portion 4 is heat-sealed and is provided between the two sheets 10 and 16. The air has been degassed.

FIG. 2 shows a cross section of the packaging bag 2.
Each of the sheets 10 and 16 has a two-layer structure,
The heat seal layers 12 and 20 are laminated on the inner surface of the substrate 18. In this packaging bag 2, only the outer peripheral portion 4 is heat-sealed.

The heat sealing layers 12, 20 of the packaging bag 2 sealed in this manner are in close contact with each other in the intermediate portion 6 from the outer peripheral portion 4 to the bag to be packed 8. Not in. Therefore, no problem arises when the packaged object 8 is a solid such as a confectionery. However, for example, when the packaged object 8 is a piece of meat or the like, the meat juice seeps into the intermediate portion 6 and becomes unsightly. .

In order to solve this problem, as shown in FIG. 3, there is also provided a packaging bag 2 in which the intermediate portion 6 and the outer peripheral portion 4, that is, the entire periphery of the packaged object 8 are heat-sealed. However, in the packaging bag 2 having this configuration, the gravy and the like do not seep into the intermediate portion 6, but the opening by peeling is not easy.

In each of the above conventional examples,
Both heat seal layers 12, 20 were made of the same material having the same melting temperature.

[0007]

Therefore, the main technical problem to be solved by the present invention is that, in this kind of vacuum packaging bag, both the outer peripheral portion and the intermediate portion are completely adhered to each other so that meat juice and the like do not permeate. On the other hand, it is to facilitate peeling and opening.

Another technical problem is to eliminate the need for a special bonding step at the intermediate portion of the packaging bag.

Still another technical problem is to make it possible to adjust the strength of the bonding portion at the intermediate portion of the packaging bag.

[0010]

In order to solve the above problems, according to the present invention, there is provided a vacuum packaging bag having the following structure. This vacuum packaging bag will be described in detail with reference to FIG.

That is, each of the vacuum packaging bags is
First, having a heat seal layer 12, 20 on the inner surface of 4, 18
The sheet 10 and the second sheet 16 are connected to the heat seal layer 1
They are superimposed and heat-sealed so that the substrates 2, 20 face each other. Then, both heat seal layers 1
The melting temperatures of 2,20 are different from each other. In the outer peripheral portion 4, the heat seal layers 12, 20 are fused to each other, that is, they are melted and strongly adhered. This state is shown by the grid lines in FIG. Further, in the intermediate portion 6, that is, in the portion from the outer peripheral portion 4 to the peripheral edge of the packaged object 8, only one of the heat seal layers 12, 20 is melted and weakly adhered to the other heat seal layer in a peelable manner. I have. The outer peripheral portion 4 is heat-sealed at a temperature equal to or higher than the higher melting temperature.
Is heat sealed at an intermediate temperature between a high melting temperature and a low melting temperature. Therefore, the heat seal layers 12 and 20 in the intermediate portion 6 are weakly adhered to each other as compared with the outer peripheral portion 4. The boundary between the heat seal layers 12 and 20 in the intermediate section 6 is indicated by a wavy line in FIG.

As a material constituting each of the heat seal layers 12 and 20 described above, for example, the heat seal layers 12 and 20 are used.
For one of the two, polypropylene having a melting point of 135 ° C. or more is preferably used, and for the other of the heat sealing layers 12 and 20, a polypropylene having a melting point of 95 ° C. to 105 ° C. is suitably used. Alternatively, a linear low-density polyethylene, a medium-density polyethylene or a high-density polyethylene having a melting point of 120 ° C. or more is suitably used for one of the heat seal layers 12 and 20, and the other of the heat seal layers 12 and 20 has a melting point of 90 ° C. ° C
Polyethylene, an ethylene-vinyl acetate copolymer, an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, and an ionomer at a temperature of up to 110 ° C. are preferably used. As a material of each of the base layers 14 and 18, for example, polyvinylidene chloride-coated stretched nylon is suitably used.

In the above structure, not only the outer peripheral portion 4 but also the intermediate portion 6, that is, the entire heat seal layers 12, 20 are bonded to each other around the packaged object 8. Since almost no gap is formed between them, it is possible to avoid the penetrating development of meat juice as seen in the conventional example. Further, each of the heat seal layers 12,
Although the intermediate portions 6 of 20 are heat-sealed to each other, the adhesion is weak, and therefore the separation is easy.

In the above configuration, when the packaged object 8 stored in the vacuum packaging bag needs to be sterilized by boiling, the melting point of the one heat sealing layer is lower than the sterilizing boiling temperature, and The melting point of the other heat seal layer is preferably higher than the sterilizing boil temperature.

According to this structure, one of the heat sealing layers 12, 20 in the intermediate portion 6 is softened by utilizing the sterilizing boil temperature, and the heat sealing layers 12, 20 are softened.
Is melted so that the two heat seal layers 12 and 20 can be weakly bonded to each other. That is, the adhesion of the heat seal layers 12 and 20 and the heat sterilization of the packaged object 8 can be performed simultaneously. In order to seal the vacuum packaging bag, different sealing steps are required for the outer peripheral part 4 and the intermediate part 6, respectively. However, since the boil sterilization step is used as the intermediate part sealing step, other special steps are required. No intermediate sealing step is required.

All of the above-mentioned materials constituting the heat seal layers 12 and 20 satisfy this condition.

In the above structure, the surface of the heat sealing layer having the higher melting point is more preferably uneven.

With this configuration, the contact area between the two heat seal layers 12, 20 is increased, and the weak adhesive strength between the two heat seal layers 12, 20 is increased. Therefore, the weak adhesive strength of the two heat seal layers 12 and 20 can be adjusted by adjusting the degree of unevenness formed on the surface of the heat seal layer and the number of the unevenness formed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a conventional vacuum packaging bag.

FIG. 2 is a side sectional view of a main part of the packaging bag shown in FIG.

FIG. 3 is a side sectional view of a main part of a packaging bag similar to FIG. 1 according to another conventional example.

FIG. 4 is a side sectional view of a main part of the packaging bag similar to FIG. 1 according to the embodiment of the present invention;

[Explanation of symbols]

Reference Signs List 2 vacuum packaging bag 4 outer peripheral part 6 intermediate part 8 packaged object 10 first sheet 12 heat seal layer 14 base layer 16 second sheet 18 base layer 20 heat seal layer

Claims (3)

(57) [Scope of request for utility model registration] 1. A first sheet (10) and a second sheet (16) each having a heat seal layer (12, 20) on the inner surface of a base layer (14, 18), respectively. In a vacuum packaging bag that is overlapped and heat-sealed so that they face each other, the melting temperatures of both heat-sealing layers (12, 20) are different, and both heat-sealing layers (12, 20) are formed at the outer peripheral portion (4). ) Are fused and strongly bonded to each other, while only one heat sealing layer is melted at the intermediate portion (6) inside the outer peripheral portion (4) and reaching the peripheral edge of the packaged object, and the other heat sealing is performed. Vacuum packaging bag characterized by weak adhesion to the layer. 2. The melting point of one of the heat sealing layers (12, 20) is lower than the sterilizing boil temperature, and the other melting point of the heat sealing layer (12, 20) is higher than the sterilizing boil temperature. The vacuum packaging bag according to claim 1, wherein: 3. The vacuum packaging bag according to claim 1, wherein the other surface of the heat seal layer (12, 20) is uneven.