JPS61167550A - Bag body for packaging - 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 The present invention relates to a packaging bag used for packaging pharmaceuticals, seasonings, etc., and its purpose is to impart heat sealing strength and tearability to the sealant layer. death,
Therefore, it is an object of the present invention to provide a packaging bag which has the necessary sealing properties to withstand the load of the filling, and which has excellent tearability, cuttability, and directionality of cutting.

BACKGROUND OF THE INVENTION In recent years, with the improvement of product packaging technology, the development of packaging bags has become active, and a wide variety of packaging bags have come to be provided that are tailored to the characteristics of each product.

This type of packaging bag is often opened by hand, so it is extremely important that it can be easily torn.Especially in the case of food and pharmaceutical packaging bags, individual Since it is necessary to open the bag, it is important to be able to easily tear and open the bag with the tip.Furthermore, it has the above-mentioned tearability and the tearing direction is straight, and It is desirable to be able to tear in a certain direction. Especially when the contents are liquid, powder, or granular, if the cutting direction is not consistent, there is a risk that the cut end will cover the entire bag and overflow, and care must be taken when opening the bag by hand.

The present inventors have conducted intensive research in view of the above points, and have found that non-oriented films made of resins with low secondary transition points that have been conventionally commonly used as sealant layers, such as low-density polyethylene films, EVA films, or ionomer films, have been developed as sealant layers. Density 0.94 g/cc instead of resin film
By using a uniaxially stretched polyethylene film with a thickness of 10 to 100μ, which is obtained by stretching a film made from the following linear low-density polyethylene 6 to 20 times in the vertical or horizontal direction, the desired purpose can be achieved. They have discovered that the bag has excellent heat-sealing strength, tearability, and cutting direction, and have completed a packaging bag suitable for light packaging or packaging of relatively heavy items.

Embodiments of the present invention shown in the drawings will be described in detail below. FIG. 1 is a partially enlarged sectional view of the packaging bag of the present invention, and FIG. 2 is a partially cutaway perspective view of the same. Bags are made of a composite film made by laminating a sealant layer 3 on one side of a base sheet 1 such as aluminum foil or paper through an adhesive 2 such as a urethane adhesive.

The sealant layer 3 in the present invention has a density of 0.94
A film made of linear low-density polyethylene of 6 to 20 g/cc or less in the vertical direction or in the horizontal direction
A uniaxially stretched polyethylene film having a thickness of 10 to 100 μm that has been stretched twice, preferably a horizontally stretched polyethylene film that has a thickness of 10 to 100 μm that has been stretched 8 to 13 times in the transverse direction is used.

In addition, in the -axially stretched polyethylene film, if the stretching ratio is 6 times or less, sufficient molecular orientation cannot be obtained, so when it is torn along the stretching direction, it cannot be cut linearly. If it is more than twice that, it is not only difficult to stretch, but also the heat sealing strength is reduced. In addition, if the thickness is less than 10μ, the heat sealing strength will be poor and the cutting direction will not be imparted and the influence will be lost.On the other hand, if the thickness is more than 100μ, the workability and economy during heat sealing will be reduced. It has poor performance and defeats the purpose of the present invention.

As is clear from the above, the present invention has a density of 0.94 by applying an adhesive to one surface of a base sheet such as aluminum foil or paper.
From a uniaxially stretched polyethylene film with a thickness of 10 to 100 μm, which is obtained by stretching a film made of linear low-density polyethylene of less than A composite film made of a layered sealant layer is made by aligning the stretching direction of the sealant layers and heat-sealing the surroundings to form a bag, so when it is torn, it opens in a straight line and can be opened with a fingertip. Unlike conventional products, where a part of the cut is cut off and cannot be opened, or the cut spreads over the entire bag and the contents spill out, it is not inconvenient, and because the sealant layer itself is oriented, light packaging is possible. It is originally preferred for packaging relatively heavy fillings, and since it has an integral sealant layer, it is extremely convenient for forming bags, and can be mass-produced using automatic packaging machines, which is advantageous for packaging work. It is.

Next, examples of the present invention will be shown, but the present invention is not necessarily limited to these examples.

Example 1 A polypropylene double-wheel stretched film with a thickness of 20 μm was laminated on one side of an aluminum foil with a thickness of 7 μm and an elongation of 2.4% (longitudinal direction) and 5.5% (horizontal direction), and a stretched polypropylene film with a thickness of 20 μm was layered on the other side. to 1
A composite film was formed by layering linear low-density polyethylene transversely stretched films having a density of g/cc and having a thickness of 30 μm that had been stretched twice. The resulting composite film has an Elmendorf tear strength (transverse direction) of 156 g edge tear resistance.
(Longitudinal direction) 26.1 kg ~ (Horizontal direction') 10.4 kg Physical properties: It can be easily torn with a fingertip, and the cutting condition is almost straight, with good hand cutability and cutting direction. This composite film was doubled so that the sealant layers faced each other, the stretching directions of the horizontally stretched films were aligned, and the periphery of the overlap was heat-sealed to form a bag.

The obtained packaging bag had excellent hand-cutting properties and cutting direction, and also had good heat-sealing strength as shown in FIG. 3.

Example 2 Thickness: 7μ, elongation: 2.4% (vertical direction), 5.5% (horizontal direction) One side of the aluminum foil is stretched 3 times vertically and 3 times horizontally. A composite film is formed by layering a 12μ biaxially stretched polyester film, and on the other side a linear low density polyethylene longitudinally stretched film with a density of 0.930 g/cc, which is 30μ thick and stretched 7 times in the longitudinal direction. did.

The resulting composite film has an Elmendorf tear strength (transverse direction) of 125 g, edge tear resistance (longitudinal direction) of 25.5 kg - (
It has physical properties of 8.1 kg (in the transverse direction), can be easily torn with a fingertip, and the cutting state is almost a straight line, with good hand cutability and cutting direction. The longitudinally stretched films were doubled so as to face each other, the stretching directions of the longitudinally stretched films were aligned, and the overlapping periphery was heat-sealed to form a bag.

The IM-processed packaging bag had excellent hand canting properties and cutting direction, and also had good heat sealing strength as shown in FIG.

[Brief explanation of drawings]

Fig. 1 is a partially enlarged sectional view of the packaging bag of the present invention, Fig. 2 is a partially cutaway perspective view of the same, and Fig. 3 shows the heat seal strength of the same embodiment. 1-1 Base sheet 2-1 Adhesive 3--Sealant layer 1 Fig. 1@a 1 jia drawing...ll・arttotie14・4o16e+ffehi)-Shi-nori grade 1@C

Claims (2)

[Claims] (1) A film made of linear low-density polyethylene with a density of 0.94 g/cc or less is attached to one side of a base sheet such as aluminum foil or paper with an adhesive, and the film is attached to one side of a base sheet, such as aluminum foil or paper, at 60° in the vertical or horizontal direction. ~20 times stretched thickness 10~10
A composite film formed by layering a sealant layer made of a uniaxially stretched polyethylene film of 0μ is formed into a bag shape by overlapping the sealant layers with their stretching directions aligned, and melting and pasting the sealant layers. A packaging bag for (2) A transversely oriented polyethylene film with a thickness of 10 to 100μ, whose sealant layer is made of linear low-density polyethylene with a density of 0.94 g/cc or less and stretched 8 to 13 times in the transverse direction. The packaging bag according to claim 1, characterized in that: