JPS61287551A - Gusset bag - 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 [Field of Industrial Application] The present invention relates to a cassette bag, and particularly to a cassette bag with good printability and heat sealability.

(Prior Art) Conventionally, cassette bags have been used to package or enclose various items, and paper has been used as the material for making such cassette bags.However, paper is a weak material. They have the disadvantage of being easily damaged.For this reason, synthetic resin films such as polyolein films such as polyethylene film-polypropylene film have come to be widely used in place of paper.

When manufacturing cassette bags using the polyolefin film as described above, various patterns or designs are printed on the polyolefin film in advance and one gusset (
The bag is cut into a so-called heat-sealed bag by heating the part corresponding to the bottom of the bag using, for example, a hot plate type.

(Problems to be Solved by the Invention) In the cassette bag using the above-mentioned polyolea in film, the ink for various designs on the polyolea in film has poor adhesion and easily rubs off.
It has a disadvantage.

For this reason, polyolefin films are usually treated with corona discharge before printing various designs with ink. The polyolefin film subjected to the discharge treatment has good adhesion to printing ink, and is then heat-sealed in a cassette. This has the disadvantage that the heat sealability deteriorates and the bottom of the bag tends to peel off.

Therefore, an object of the present invention is to provide a cassette bag which has good printability, that is, good ink adhesion, and good heat sealability, that is, good adhesiveness at the sealed portion.

[Means to solve the problem]

The present invention resides in a cassette bag made of a laminated film having an outer layer of a corona discharge-treated ethylene vinyl acetate copolymer film and an inner layer of a polyoleain film.

As a material for making the cassette bag of the present invention, a laminated film of an ethylene vinyl acetate copolymer film and a polyolefin film is used.

Such laminated films can be made using conventional laminated film manufacturing methods, such as blown-in or cast methods.

Examples of polyolein that can be used include polyethylene, polypropylene, and mixtures thereof such as polyethylene propylene copolymer.As for the ethylene vinyl acetate copolymer, ethylene vinyl acetate copolymers with various vinyl acetate contents available on the market can be used. Can be used.

According to the present invention, the ethylene vinyl acetate copolymer layer of the ethylene vinyl acetate copolymer and polyolein laminated film produced as described above is subjected to a corona discharge treatment.

This corona discharge treatment may generally be between 39 and 44 dynes.

According to the present invention, as described above, a laminated film having an ethylene vinyl acetate film layer subjected to corona discharge treatment as an outer layer and a polyolein film layer as an inner layer is used, and various designs are pre-printed on the outer layer of an ethylene vinyl acetate copolymer film. After printing with ink, a cassette is installed, heat-sealed, and cut appropriately. Furthermore, the inner layer of the polyolefin film may be reinforced by having two or more layers.

[For production]

According to the present invention, since the outer layer of the laminated film is an ethylene vinyl acetate copolymer film treated with corona discharge as described above, printability with printing ink is improved.
It has the advantage that small and complicated designs can be printed clearly.

If you do not perform corona discharge treatment, the clarity of small, complex designs may be poor or may not be obtained, and small bubbles may form in the adhered ink, so corona discharge treatment is performed. .

According to the present invention, a cassette is provided using the above-mentioned discharge-treated laminated film with its ethylene vinyl acetate copolymer film layer as an outer layer, and then a portion corresponding to the bottom of the bag is removed by a well-known method such as a hot plate type. Heat seal it into a single strip using a bag making machine.

At this time, in the cassette (fold), the ethylene-vinyl acetate copolymer films subjected to the above-mentioned corona discharge treatment are adhered to each other, so that good adhesive strength, that is, heat-sealability, as described above is achieved. In addition, in areas other than the cassette, the layers of the polyoleain film that constitute the inner layer adhere to each other, that is, form a heat seal, but since the aforementioned corona discharge treatment is mainly performed on ethylene vinyl acetate copolymer films, Unlike the conventional case where a polyolefin film is directly subjected to corona discharge treatment, there is little modification of the polyolefin film due to the discharge treatment, so there is no deterioration of the heat sealing property, or even if there is, there is very little damage. Therefore, the heat sealability between the polyolefin films is also good, and therefore the heat sealability at the bottom of the gasket bag is good as a whole.

〔Example〕

Hereinafter, the present invention will be described by way of examples with reference to the drawings.

Example 1.

Polyester vinegar, acid vinyl copolymer (evatate).

The outer layer was made of a mixture of vinyl acetate, chill content 5% by weight, manufactured by Sumitomo Chemical Co., Ltd.) and lubricant MB (manufactured by Sumitomo Chemical Co., Ltd.) 5% by weight.・Using a mixture of lubricant M15 weight class material MB (manufactured by Sumika Color Co., Ltd.) 10% by weight as the inner layer, each was simultaneously extruded using a 40 tone 2-layer in-7 ration extruder. It was molded into a tube shape. The outer layer of this extruded tube was corona discharge treated at 42 dynes. The molding temperature is 170℃ for the outer layer (Cylinder temperature 170℃)
℃, one temperature of the adapter is 170°C, one temperature of the inner layer is 180°C, one temperature of the adapter is 180°C,
The die temperature was 180°C.

The molding width was 430 rrans, the inner layer thickness was 45 μm, and the outer layer thickness was 15 μm.

Next, a continuous pattern was printed on the entire front and back surfaces of the tube with a length of 500 mm.

Next, the cassette 1 was placed in this tube as shown in the first example. The folding depth at this time was 50 mm.

Next, as shown by 2 in FIG. 1, a portion corresponding to the bottom of the bag, including the cassette portion, was heat-sealed using a hot plate bag making machine and cut.

The thus produced cassette bag had good printability and ink adhesion and was clear, and also had excellent adhesion at the heat-sealed portion.

〔Effect of the invention〕

According to the present invention, since an ethylene vinyl acetate film layer subjected to corona discharge treatment is used as the outer layer and a polyolefin film layer is used as the inner layer, a cassette bag with excellent printability (and excellent heat sealability) can be easily rolled. Compared to conventional cassette bags made only from polyolefin film treated with corona discharge, the production rate can be reduced due to poor heat sealability.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a cassette bag according to the present invention. 1 is the cassette part, 2 is the heat seal part.

Claims (1)

[Claims] 1. A cassette bag comprising a laminated film having an outer layer of an ethylene vinyl acetate copolymer film treated with corona discharge and an inner layer of a polyolefin film.