JPH0312687Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is suitable for packaging products that require light shielding, such as X-ray film, photographic paper, and more. Therefore, the present invention relates to a packaging material that can be preferably used for bag making or automatic packaging.

(Prior art) For example, high density polyethylene, polypropylene,
Yarn cloth, which is a strip of uniaxially stretched film made from thermoplastics such as polyester or nylon, and is woven with thin strips called flat yarn, ribbon yarn, flat yarn, etc., as warp and weft yarns is used as a packaging material for various products. Although it is used,
It has not yet been used as a packaging material for products that require light shielding.

(Problem to be solved by the invention) In order to use yarn cloth as a packaging material to package products that require light shielding, the packaging material must have light shielding properties. Packaged items are required to be completely sealed and the seal must not be easily peeled off or damaged, and there are still no products that meet this requirement. It has not been.

(Means for solving the problem) For this reason, the inventor of the present invention, when making bags from packaging materials,
Or when sealing the bag after filling it with the product,
Alternatively, since heat fusion is the most preferable method for sealing the packaging materials together when they are applied to an automatic packaging machine, it is preferable to use yarn cloth to provide light-shielding properties and achieve sealing by heat fusion. As a result of intensive study and various experiments to obtain packaging materials,
One side of the core material layer made of yarn cloth is coated with a low-temperature resin layer made of a resin that melts at a lower temperature than the yarn cloth, and the other side is coated with a low-temperature resin layer made of a resin that melts at a lower temperature than the yarn cloth.
It has a heat-resistant layer made of a resin film, metal foil, paper, etc. that melts at higher temperatures, and all or any of these layers are covered with light-shielding materials such as carbon, titanium oxide, and inorganic materials. This objective can be easily achieved by creating a packaging material with light-shielding properties, which is obtained by adding a light-shielding material or by applying metal vapor deposition on one or both sides of the resin film. That's what I got.

(Function) When making bags with the packaging material of this invention, a low-temperature resin layer made of a resin that melts at a lower temperature than the yarn cloth, provided on one side of the core material layer made of yarn cloth, becomes the inner surface of the bag. superimposed on,
At this time, the outermost layer is thermally stable because it is a heat-resistant layer, the yarn cloth that is the core material is also thermally stable, and only the inner layer, which is a low-temperature resin layer, is thermally fused. The core material layer and outer layer are thermally stable through heating for heat-fusion, so there is no shrinkage or deterioration of strength due to heat. .

(Example) An example of the implementation of this invention will be explained with reference to the accompanying drawings. In Fig. 1, 1 is a layer of core material made of carbon-containing yarn cloth, and 2 is a low-temperature resin layer, which is made of yarn cloth. It is made of a resin that melts at a lower temperature than the cloth 1, such as linear low-density polyethylene, and contains about 3% carbon. 3 is a heat-resistant layer, which is integrated by a film such as a high-density polyethylene film or an extruded polyethylene laminate 4 that melts at a temperature equal to or higher than that of the yarn cloth. The one in Figure 2 is a yarn cloth that does not contain carbon as the core layer 1, and the low temperature resin layer 2
The material is ethylene vinyl acetate copolymer (EVA) mixed with about 3% carbon, and the heat-resistant layer 3 is a high-density polyethylene film, one side of which is coated with aluminum vapor deposition 5. It is held together by an extruded polyethylene laminate 4. The one in Figure 3 is a yarn cloth that does not contain carbon as the core layer 1, and 3% as the low temperature resin layer 2.
The heat-resistant layer 3 is a carbon-containing high-density polyethylene film that has been uniaxially obliquely stretched at 45 degrees. 4, it is integrated into the yarn cloth 1. In the case shown in Figure 4, the core material layer 1 is carbon-free yarn cloth, and the low-temperature resin layer 2 is ethylene acrylic acid copolymer (EAA) mixed with about 3% carbon. As the elastic layer 3, aluminum foil is integrated with the yarn cloth 1 by extrusion lamination of polyethylene. When making a bag from the packaging material thus made, or when sealing the bag after it is made into a bag, the low-temperature resin layers of the packaging material may be overlapped and heat-fused.

In this invention, the yarn cloth is preferably made of a film made of high-density polyethylene or polypropylene, and the film used as the yarn cloth may be transparent, but carbon, titanium oxide, etc. , a light shielding material such as an inorganic substance may be mixed.

In this invention, low-density polyethylene or the like is preferably used as the low-temperature resin layer.

In this invention, a stretched or unstretched film of polyester, nylon, polypropylene, etc., metal foil, paper, etc. is preferably used as the heat-resistant layer, and the film contains light-shielding materials such as carbon, titanium oxide, and inorganic materials. A material may be mixed therein, or one or both sides of the film may be vapor-deposited with aluminum or other metal.

(Effects of the invention) Since this invention is constructed as explained in detail above, when making bags using this packaging material or when applying it to an automatic packaging machine, it is possible to form a bag body by heat fusing. The heat for fusing reaches the low-temperature resin layer through the heat-resistant layer and core layer on the uppermost side of the packaging material, and fuses this low-temperature resin layer. As long as the treatment is carried out at an appropriate temperature, the heat-resistant layer, which melts only at a higher temperature than the low-temperature resin layer, will not be thermally affected at that temperature. Because the bag does not shrink or the boundary between the adhesive part and the main body becomes weak, the bag retains its beautiful appearance and its strength is not compromised in any way. It is now possible to seal the opening of the bag, which maintains great strength due to the yarn cloth, provides sufficient light shielding on both sides of the yarn cloth, and provides heat-fusible properties. This is an excellent invention that has been put to practical use as a packaging material for products that require.

[Brief explanation of the drawing]

The attached drawings are for explaining this invention, and FIG. 1 is a longitudinal side view showing an example of the implementation of this invention;
FIGS. 2 to 4 are longitudinal sectional side views showing another example of the embodiment. 1... Core material layer, 2... Low temperature resin layer, 3... Heat resistant layer.

Claims (1)

[Scope of utility model registration request] One side of the core layer made of yarn cloth has a low-temperature resin layer made of a resin that melts at a lower temperature than the yarn cloth, and the other side has a resin layer that melts at the same or higher temperature than the yarn cloth. It has a heat-resistant layer made of film, metal foil, paper, etc., and a light-shielding material such as carbon, titanium oxide, or an inorganic material is mixed into all or any of these layers, or one side of the resin film is mixed with a light-shielding material such as carbon, titanium oxide, or an inorganic material. Or a packaging material with light-shielding properties, characterized in that it is made by applying metal vapor deposition on both sides to impart light-shielding properties.