JPH0360655B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic synthetic resin sheet body, particularly a sheet body used as a sealed packaging material. The object of the present invention is to obtain a sheet body that can be easily opened and torn despite the fact that it is difficult to unseal it.

Packaging sheets made of thermoplastic synthetic resin are often used for hermetically sealed storage of ham, sausage, cheese, and other items. Measures were taken, such as making a cut in the material itself in advance to make it easier to break, or gluing other parts (pull tabs) etc. in advance.

For this reason, post-processing such as forming notches or adhesion forming of parts is required after forming the sheet-like body alone, making the forming operation complicated.

Further, in the case where the notches are shaped, a local thin portion is formed in a part of the sheet body, so there is an inconvenience that the tensile strength etc. of the sheet body itself deteriorates.

On the other hand, for those that glue other parts,
Basically, it loses its single-sheet form, making it unsuitable for use in almost sealed packaging applications, and the sheet becomes inconvenient to handle because it has a front-back relationship. The problem was that the types of items that could be packaged were limited.

The present invention was devised to solve the above-mentioned drawbacks of the conventional examples, and it combines a thermoplastic synthetic resin material with another thermoplastic synthetic resin material that has low or no adhesion to the thermoplastic synthetic resin material. This method takes advantage of the ease with which both resin materials can be peeled off in an integral product extruded together.

The present invention will be described below with reference to drawings showing embodiments thereof.

The synthetic resin sheet body according to the present invention has a part of the sheet-like base body 1 molded from an appropriate thermoplastic synthetic resin material, which has adhesive properties to the thermoplastic synthetic resin material from which the sheet-like base body 1 is molded. It is constructed by burying an elongated string-like body 2 molded from a synthetic resin material with extremely low thermoplasticity.

That is, only the sheet-like matrix 1 functions as a packaging material, and the string-like body 2 does not function as a packaging material at all.

Therefore, the sheet-like matrix 1 is molded from a mechanically strong thermoplastic synthetic resin material that is excellent in content resistance and has high various Bayer properties.On the other hand, the string-like body 2 is It goes without saying that the adhesion to the material is extremely low, but it is desirable that the material be molded from a thermoplastic synthetic resin material with high tensile strength.

For example, polyethylene resin is suitable as the thermoplastic synthetic resin material for forming the sheet-like base 1, and polypropylene resin is suitable as the thermoplastic synthetic resin material for forming the string-like body 2. .

The shape of the synthetic resin sheet according to the present invention is not limited; for example, it may be a simple sheet as shown in FIG. 1, or a thin cylinder as shown in FIG. It may be a shape.

Furthermore, the buried form and buried position of the string-like body 2 with respect to the sheet-like base body 1 are not similarly limited, and may be linear as shown in FIGS. 1 and 2, or may be in other shapes. The shape may be circular, for example.

Regardless of the overall shape of the string-like body 2, since the string-like body 2 is buried in the sheet-like base body 1 formed into a thin sheet shape, as is clear from the cross-sectional shape shown, the string-like body 2 is Of the sheet-like base body 1 portions located around the body 2, the sheet-like base body 1
The portions 1a located on both surface sides are extremely thin.

Therefore, when the tip of the string-like body 2 is pulled up by an appropriate means, the adhesiveness between the string-like body 2 and the sheet-like base body 1 is extremely low, and the portion 1
Since part a is extremely thin, one part 1
a are sequentially broken as the string-like body 2 is pulled up.

In this way, when the string-like body 2 is taken out from the sheet-like base body 1, one part 1a is broken due to the removal operation of the string-like body 2, and the part of the sheet-like base body 1 where the string-like body 2 was , are connected only by the other extremely thin portion 1a.

Therefore, if a tensile force is intentionally applied to this portion 1a, this portion 1a will easily break, thereby achieving breakage of the sheet-like matrix 1.

On the other hand, before one part 1a is broken by pulling up the string-like body 2, both parts 1a, 1
This means that they are connected in series at point a, and therefore can exhibit considerable durability against external tensile forces.

If there is any concern about the tensile strength of the sheet-like base body 1 in which the string-like body 2 is buried, the synthetic resin material for molding the string-like body 2 may be different from the synthetic resin material for molding the sheet-like base body 1. It is sufficient to use a material that exhibits a certain degree of adhesive strength, or the thickness of the string-like body 2 in the thickness direction of the sheet-like matrix 1 may be reduced to increase the thickness of the portion 1a to a certain extent.

In addition, since the string-like body 2 is located completely buried in the sheet-like base body 1, the surface of the sheet-like body as a whole is smooth, and therefore, there is no possibility that a front-back relationship will occur in the sheet-like body. Since it can be handled in the same way as a normal sheet body, it is easy to handle and process it.

Furthermore, since the sheet body according to the present invention is molded by simultaneously extruding the sheet-like matrix 1 and the string-like body 2 using the same extruder, there is no need for any post-processing, and the molding operation is also performed by extrusion. pressure control,
It can be set arbitrarily by temperature control, etc.

As is clear from the above description, the sheet body according to the present invention has completely smooth surfaces on both sides, so there is no front-back relationship, and this makes handling and forming a package extremely easy, and the sheet body has a completely smooth surface. Since the tensile strength before removing the string-like body 2 can be increased, anxiety caused by insufficient tensile strength in this type of packaging sheet can be greatly reduced, and furthermore, when the string-like body 2 is pulled up and one part 1a is It has many excellent functions and effects, such as being able to easily and reliably break it with the action of a small amount of force.

[Brief explanation of drawings]

Figures 1 and 2 are perspective cross-sectional views of main parts showing different embodiments of the present invention, with Figure 1 showing the case where it is applied to a simple sheet-like body and Figure 2 showing the case where it is applied to a cylindrical body. It is something. Explanation of symbols: 1... Sheet-like matrix, 2... String-like body, 1a... Part.

Claims (1)

[Claims] 1 A part of a sheet-like matrix molded from an appropriate thermoplastic synthetic resin material is molded from a thermoplastic synthetic resin material that has extremely low adhesiveness to the thermoplastic synthetic resin material from which the sheet-like matrix is molded. A synthetic resin sheet body consisting of a long, slender string-like body embedded in the body.