JPH0891450A - Degasification structure for plastic bag or container - Google Patents

Abstract

PURPOSE: To provide a bag or a container having a breathing structure that can be produced at a low cost and is capable of being safe in use in a microwave oven because of its structure available for instantaneous degasification. CONSTITUTION: An internal plastic film 1, with a number of pares 10 provided all over the surface, and an external plastic film 2, not sticking by heat-sealing to the internal film 1, are stuck together discontinuously in lattice-like adhesion with an adhesive 3 with one side left unstuck, and thereby a composite film K is formed. Outer peripheral parts to be stuck of the internal films l are placed face to face, and heating is applied from the external film 2 side for pressure sticking. Thereby, a bag body is made by heat-sealing with the internal films 1 in the same quality sealed up together by heating, while parts of the external films 2 to which heating is applied for pressure sticking are left unstuck to the internal films 1 on heat-sealing. The pores 10 of the internal films 1 on the unstuck points 30 in the discontinuous sticking are made to communicate with spaces 4 between the internal films 1 and the external films 2 on the parts unstuck on heat-sealing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degassing structure in a plastic bag or container, which produces fermented foods such as natto, miso, pickles and raw noodles which generate gas, or a culture clay bag for fungi, etc. Alternatively, it is used in a cooking bag or container suitable for a microwave oven that heats to generate gas.

[0002]

2. Description of the Related Art Conventionally, ventilators and vent valves have been used to improve ventilation in the bag, but the ventilation structure is complicated and the cost is high. The internal pressure increased and the bag burst, which was dangerous.

[0003]

SUMMARY OF THE INVENTION Therefore, the present invention provides an inexpensive ventilation structure by dry-adhesion of a plastic film, and also provides a safe bag or container for a microwave oven capable of rapidly degassing. To do.

[0004]

Therefore, according to the present invention, at least one side end portion of a plastic inner film having a large number of fine holes formed therein and an outer film made of a plastic film which is not heat-welded to the inner film are provided. A separate material having a plastic film of the same material that is heat-welded to the inner film as a heat-sealing portion to form a composite film that is intermittently adhered with an adhesive Of the same material and the plastic of another material are heat-welded to each other to form a bag body or a container body, or a bag body or a container. The body can be sealed, and the heating pressure contact part of the outer film is a non-welding part that does not weld to the inner film, and there is no adhesion due to intermittent adhesion near the heat seal. Microporous inner film parts have a structure which communicates with the gap-free welding of the inner film and outer film. In addition, you may use the same composite film as another material body. Further, an inner film having a large number of fine holes all over the surface and an outer film made of a plastic film which is not heat-welded to the inner film are intermittently weakly bonded by an adhesive except at least one side end. To form a peelable composite film, and the outer peripheral part of the inner film to which the inner film is to be adhered is attached to the heat seal part of a separate material whose heat seal part is the plastic of the same material which is heat-welded to the inner film. The inner and outer plastics of the same material and the plastic of another material are heat-welded to each other to form a bag body or a container body by bringing them into contact with each other and heating and pressure-bonding each other, and the heating and pressure-contacting portion of the outer film and the inner film It is a non-welding part that does not weld, and the micropores of the inner film of the non-adhesive part due to intermittent adhesion near the heat seal are Communicated with the gap,
The outer film may be partially peeled off due to an increase in the internal pressure of the bag body or the container body. The composite film may be formed in a small sheet shape, and the outer peripheral portion of the inner film may be heat-sealed in an opening formed through the bag or container body of another material.

[0005]

[Function] The inner surfaces of the composite film are brought into contact with each other, or the heat-sealed portions of the composite film and the separate material are brought into contact with each other, and the portions to be the seal portions are heated and pressure-welded to each other, thereby making the same material inside The inner film and the plastic of another material are heat-welded to each other to form a bag or a container by heat sealing, or when the another material is a bag or a container, the composite film is heat-sealed in the opening. In the case, the bag body or the container body is sealed. Then, the heat-pressure contact portion of the outer film at the one end is in a non-welding portion state in which it does not weld to the inner film because of a material that does not heat-weld with them, and because of intermittent adhesive bonding, the adhesive-free portion near the heat seal The fine holes in the inner film communicate with the gaps between the inner film and the non-welded portion of the outer film for ventilation.

The gap between the non-welded portions of the inner film and the outer film is normally closed except for a slight gap by the force applied by the pressing operation during heat sealing, but a small gap is sufficient for ventilation. . Then, when the internal pressure of the bag body or the container body suddenly increases due to use in a microwave oven or the like, the released gas opens the outer film of the non-welded portion near the heat seal to expand the gap, and the micropores in that portion. The gas is emitted from the unshielded. This prevents damage to the bag or container.

Further, the inner film and the outer film are
In a composite film that can be peeled by intermittently weakly adhering with an adhesive, the internal pressure of the bag or container rapidly increases due to use in a microwave oven, etc., and due to the gas released from the fine holes of the inner film, Peeling occurs from the outer film of the non-welded portion due to intermittent adhesion near the heat seal, and a large number of fine holes are exposed. As a result, a large amount of gas is released from the exposed micropores, and the bag or container is further prevented from being damaged.

[0008] If separate materials are adhered to each other as the same composite film so as to be opposed to each other, ventilation is secured on both sides of the composite film, and the number of open fine holes is increased to prevent damage to the bag or container due to an increase in internal pressure. It can be done well. If the inner surface of the separate material is a plastic non-woven fabric that can be heat-welded to the inner plastic of the composite film, or if a non-woven fabric is interposed between the inner plastic and the outer surface material, the back flow of liquid such as drip absorbed by the non-woven fabric can be prevented. It is possible to prevent deterioration of taste.

[0009]

Embodiment 1 Hereinafter, the details of the present invention will be described with reference to illustrated embodiments. The example shown in FIGS. 1 and 2 is formed into a bag body. First, the inner unstretched polypropylene film 1
Innumerable fine holes 10 are formed in the inner surface of the inner film 1 and the outer film 2 made of a polyester film made of a material which is not heat-welded, and intermittently dry-bonded with an adhesive 3 except for one end. The film K is formed.

The thickness of the inner film 1 is 50 μm,
The outer film 2 has a thickness of 20 μm, and the fine holes 10 formed on the entire surface of the inner film 1 have a diameter of 450 μm, which is 600,000 pieces /
m ^{2 is} transparently installed. Further, the fine holes 10 are formed by inserting a large number of heating needles protruding around the roller into the inner film 1 to form holes, and the small protrusions 101 are formed around the fine holes 10 on the insertion side of the heating needle. Is laid around. The small projection 101 side is bonded to the outside film 2 on the outside.

Further, the thickness of the layer of the adhesive 3 is about 10 μm.
Then, as shown in FIG. 3, the adhesive 3 is applied by printing in a diagonal grid pattern. For this reason, the inner film 1 and the outer film 2 are adhered in a lattice shape, and the adhesive-free portion 30 is formed in the lattice to form an intermittent adhesive state, and the micropores 10 are closed by the adhesive 3 in the adhesive portion. is there.

Then, the composite film K is bent, or two composite films K are used to form the inner film 1 respectively.
The outer film 2 to be bonded to the outer film 2
The one end portion without adhesive 3 is heated and pressure-welded. As a result, the inner film 1 of the same material is heat-sealed to each other to form a bag by heat sealing, and as shown in FIG.
The heating press contact portion of each outer film 2 is in a state of a non-welded portion which is not welded to the inner film 1.

According to this embodiment, the inner films 1 are heat-sealed to each other to form a bag, and the microscopic holes 10 of the inner film 1 of the adhesive-free portion 30 due to intermittent adhesion in the vicinity of the heat seal.
However, since it communicates with the gap 4 of the non-welded portion of the inner film 1 and the outer film 2, air permeability is ensured. In addition,
The fine holes 10 in the heat-sealed portion of the inner film 1 are clogged and disappeared by heat melting to be in a non-hole heat-welded state.

At this time, the other micropores 10 except for the micropores 10 near the heat seal are clean because they are closed by the outer film 2, and invasion of various bacteria is prevented. It should be noted that various bacteria may enter from the micropores 10 near the heat seal, but due to the straight-moving nature of the bacteria, even if they enter from the gap 4 of the non-welded portion, they rarely enter the micropores 10. Since the intrusion is blocked by the small protrusions 101 around the micropores 10, the actual invasion of various bacteria is extremely small.

Further, when gas is rapidly generated due to use in a microwave oven and the internal pressure of the bag increases, as shown in phantom line in FIG. 1 and FIG. The outer film 2 is pushed open and the gap 4 is expanded. A large amount of gas is released from the micropores 10 at that portion, which lowers the internal pressure of the bag, prevents damage, and ensures safety.

[0016]

[Embodiment 2] In this embodiment shown in FIG. 4, a plastic container main body 5 which is a separate material having an unstretched polypropylene film 51 on the inner surface is covered with the composite film K having the above-mentioned structure. The inner film 1 of the composite film K is heat-sealed and adhered. As a result, the heating and pressure-bonding portion without the adhesive 3 at one end of the outer film 2 becomes a non-welded portion that does not weld with the inner film 1, and as in the previous example, the adhesive-free portion due to intermittent adhesion near the heat seal. The fine holes 10 of the inner film 1 of 30 communicate with the gap 4 of the non-welded portion of the inner film 1 and the outer film 2 so that air permeability is ensured.

When used in a microwave oven, similarly, the outer film 2 at the non-welded portion near the heat seal is opened and the gap 4 is enlarged, and a large amount of gas is released from the fine holes 10 at that portion to damage the bag. Is prevented. If the plastic container body 5 itself is made of unstretched polypropylene, it can be heat-sealed with the inner film 1 of the composite film K.

[0018]

[Embodiment 3] In this embodiment shown in FIG. 5, the composite film K having the above-mentioned structure is used as a lid to form a gusset-shaped bag by adhering to another material. The inner film 1 is made of a non-stretched polypropylene non-woven fabric 61 that can be heat-welded to the inner surface, and the plastic film 62 is adhered to the outer surface.

As a result, the heat-pressed portion without the adhesive 3 at one end of the outer film 2 becomes a non-welded portion that is not welded to the inner film 1 and, as in the previous example, there is no adhesive due to intermittent adhesion near the heat seal. Inside film 1 of the adhesive part 30
Since the micropores 10 communicate with the gap 4 of the non-welded portion of the inner film 1 and the outer film 2, the air permeability is ensured, and when used in a microwave oven, the outer film 2 of the non-welded portion near the heat seal is similarly formed. The gap 4 is opened and the amount of released gas is increased to prevent the bag from being damaged. In this example,
Since the nonwoven fabric 61 absorbs the liquid content such as drip from the stored food, the taste can be maintained.

[0020]

[Embodiment 4] Next, in the present embodiment shown in FIG. 6, the composite film K having the above-mentioned structure is used, but the outer film 2 is weakly adhered so that it can be peeled off, and the composite film K is bent, Or using two composite films K,
The outer peripheral portions of the inner film 1 to be bonded are brought into contact with each other, and the outer film 2 is heated and pressed from one end thereof. As a result, similar to the first embodiment, the inner film 1 made of the same material is heat-sealed to each other to form a bag, and the outer film 2 is heated without adhesive 3 at one end of each outer film 2. The pressure contact portion is in a state of a non-welded portion that is not welded to the inner film 1.

According to this embodiment, the inner films 1 are heat-sealed to each other to form a bag body, and like the first embodiment, the fine holes 10 of the inner film 1 of the adhesive-free portion 30 due to the intermittent adhesion in the vicinity of the heat seal. Since the inner film 1 and the outer film 2 communicate with the gap 4 of the non-welded portion, air permeability is ensured.

Then, when gas is generated suddenly and the internal pressure of the bag increases due to use in a microwave oven, as shown in FIG.
The released film peels the outer film 2 from the non-welded portion near the heat seal, and the space 40 expands. As a result, a large amount of gas is released directly from the open micropores 10 to reduce the internal pressure of the bag, preventing its damage and ensuring safety.

[0023]

[Embodiment 5] This embodiment shown in FIG. 7 uses the composite film K of Embodiment 4 which is weakly adhered so that the outer film 2 can be peeled off, and has an unstretched polypropylene film 5 on its inner surface.
1 is a plastic container main body 5 of a separate material having 1 and is covered with a composite film K, and the inner film 1 of the composite film K is heat-sealed and adhered to the film 51.

According to this embodiment, as in the case of the fourth embodiment, the fine holes 10 of the inner film 1 of the adhesiveless portion 30 due to the intermittent adhesion in the vicinity of the heat seal are the inner film 1 and the outer film 2.
As it communicates with the gap 4 of the non-welded part, the air permeability is secured, and when the gas is rapidly generated by the use in the microwave oven to increase the internal pressure of the bag, the gas released as shown in FIG. As a result, the outer film 2 is peeled off from the non-welded portion near the heat seal, the space 40 expands, gas is directly discharged from the fine holes 10 to lower the internal pressure of the bag, and the damage is prevented and safety is secured. is there.

In this example, the unstretched polypropylene film 51 on the inner surface of the plastic container body 5 which is a separate material has a large number of fine holes 53 formed on its bottom surface, and the outer container body 5
Since the non-woven fabric 54 is interposed between the non-woven fabric and the liquid, the liquid content of the drip or the like of the contained substance, etc. passes through the fine holes 53 and is absorbed by the non-woven fabric 54, and the inner bottom surface of the container body 5 is kept clean. You can do it.

Although each of the embodiments has the above-mentioned structure, the present invention is not limited to this. For example, regardless of the plastic material of the inner film, various plastics such as polyethylene can be used. Also, the plastic material of the outer film is not limited, but any plastic that does not heat-weld to the inner film may be used, and a composite film may be used. The size and number of the fine pores formed through the inner film are not limited, but a pore diameter of 200 to 600 μm is preferable, and the number depends on the pore diameter, but 20 to 700,000 /
m ² is suitable. Further, the fine holes may be transparently provided near the seal portion.

Further, the kind of adhesive for adhering the inner film and the outer film is appropriate, and any means for intermittently adhering may be used. Therefore, in addition to the grid-shaped adhesion of this example, a wavy shape, a V-shape, a scattered surface adhesion such as a circular shape or a triangular shape may be used, and the adhesion pattern state is appropriate.

When the outer film is weakly adhered to enable peeling, an adhesive having a weak adhesive force is used, the amount of the adhesive applied, that is, the thickness of the adhesive is reduced, or intermittent adhesion is performed. It can be adopted by increasing the area of the non-adhesive part in the part or using a smooth film without corona discharge treatment.

The shape and structure of the separate material are not limited, either.
As long as it has a plastic material that can be heat-welded to the inner film of the composite film, it can be used as various films, sheets, or containers. Therefore, a bag as shown in FIG. 8 may be used. In particular, if the inner film has a myriad of fine holes through it and a non-woven fabric intervenes between the outer plastic material and the outer plastic material, the non-woven fabric absorbs the liquid content such as drip from the contents and prevents backflow to the inner surface. The inside of the bag or container can be kept clean.

Further, when the separate material body is a bag body or a container body, as shown in FIGS. 9 to 13, the composite film K of the present invention is heat-sealed in a small sheet shape in the opening communicating with the inside. It's okay. Even by this, the heating and pressure contact portion of the outer film 2 becomes a non-welding portion that does not weld to the inner film 1, and the micropores 10 of the inner film 1 of the adhesive-free portion 30 due to intermittent adhesion near the heat seal become the inner film 1. 1 and the outer film 2 are connected to the gap 4 of the non-welded portion, so that air permeability is secured, and in the use in a microwave oven, the outer film 2 of the non-welded portion near the heat seal is opened and the gap 4 is expanded. This is a ventilation valve that prevents the bag from being damaged due to the large amount of released gas. In the case of this ventilation valve shape, the inner film 1 and the outer film 2 may be bonded intermittently except for the non-adhesive portion 30 on the outer peripheral portion as shown in FIG. In the case of a microwave oven, the outer film 2 may be weakly adhered so that it can be peeled off, and gas can be released from the fine holes 10 exposed at the peeled portion to prevent damage to the bag body or the container body.

[0031]

According to the first aspect of the present invention, the inner film of the composite film is heat-sealed to the inner surface plastic material of another material body to form a bag body or a container body, and the composite film is not attached by intermittent adhesion in the vicinity of the heat-sealing. The fine pores of the inner film of the adhesive section communicate with the gap between the non-welded part of the inner film and the outer film to ensure air permeability, and when the internal pressure rises due to use in a microwave oven, etc., heat seals with released gas. Since the outer film of the non-welded part in the vicinity is opened, the gap expands, a large amount of gas can be released from the micropores in that part, the internal pressure drops, damage to the bag and container is prevented, and safety is secured. .

In the second aspect, since the same composite film is used to form the bag, the air permeability near each heat seal portion is ensured even on the opposite surfaces, and the internal pressure increases due to the use of a microwave oven or the like. Even when the outer film is opened to the outside on both sides, degassing can be done more quickly, damage to the bag can be prevented, and safety can be ensured. Suitable for degassing the body.

In the third aspect, since the opening can be heat-sealed to form a gas vent valve, the structure of the separate material can be arbitrarily selected, and the bag body of the finely breathing vegetables, mushrooms, flowers, seeds, etc. Alternatively, it is suitable for degassing the container body.

According to a fourth aspect of the present invention, when the inner pressure of the bag rises due to the rapid generation of gas due to use in a microwave oven, the outer film is peeled off from the non-welded portion near the heat seal by the gas, and the exposed open state is maintained. Gas is released directly from the fine holes, the internal pressure of the bag drops, and damage is prevented, ensuring safety. According to the present invention, since the same composite film is used to form the bag, the air permeability in the vicinity of each heat seal portion is ensured even on the opposite surfaces, and even when the internal pressure increases due to the use of a microwave oven or the like. Since the outer film is peeled off on both sides, the gas can be released more quickly, the bag is prevented from being damaged, and the safety can be ensured.

According to the seventh aspect of the invention, the plastic non-woven fabric can absorb the liquid component such as drip. Claim 8
In this case, the liquid content such as drip is absorbed by the intervening non-woven fabric passing through the micropores on the inner surface, and the inner surface can be kept in a smooth shape by the inner surface plastic film that prevents backflow.

[Brief description of drawings]

FIG. 1 is an enlarged transverse plan view of a main part of a bag showing an embodiment of the present invention.

FIG. 2 is a perspective view of a main part thereof.

FIG. 3 is a front view in which an outer film is cut away in a part of the composite film.

FIG. 4 is an enlarged vertical sectional side view of a main part used in a container body.

FIG. 5 is a partially cutaway enlarged vertical side view of another example.

FIG. 6 is an enlarged cross-sectional plan view of a main part in a state where the outer film is partially peeled off.

FIG. 7 is an enlarged vertical sectional side view of a main part of another example in a state where the outer film is partially peeled off.

FIG. 8 is an enlarged cross-sectional plan view of a main part of still another example.

FIG. 9 is a partially cutaway cross-sectional plan view in which the composite film is heat-sealed in the opening of the separate material body that is a bag body.

FIG. 10 is a perspective view in which the composite film is heat-sealed in the opening of another material body that is a bag body.

FIG. 11 is a partially cutaway perspective view in which a composite film is heat-sealed in a band-shaped opening of another material body as a bag body.

FIG. 12 is a perspective view in which the composite film is heat-sealed in the opening of the lid of the separate material used as the container.

FIG. 13 is a perspective view in which the composite film is heat-sealed in the small window-shaped opening of the lid of the separate material used as the container.

FIG. 14 is a partial cross-sectional plan view showing another shape of the composite film.

[Explanation of symbols]

 K Composite film 1 Inner film 10 Micropore 101 Small protrusion 2 Outer film 3 Adhesive 30 Non-adhesive part 4 Gap 40 Space 5 Plastic container body 51 Non-stretched polypropylene film 54, 61 Nonwoven fabric 8 Bag 81 Opening

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B65D 81/26 E

Claims (8)

[Claims] 1. A plastic inner film 1 having a plurality of fine holes 10 formed therethrough, and an outer film 2 made of a plastic film which is not heat-welded to the inner film 1.
A plastic of the same material that forms a composite film K which is intermittently adhered with an adhesive 3 except at least one end, and heat-welds the outer peripheral portion of the inner film 1 to be adhered to the inner film 1. A heat-sealing portion of another material having a heat-sealing portion, and by heating and press-contacting the same, the inner film 1 of the same material and the plastic of the different material are heat-sealed to each other to form a bag body. Or it can be a container body or can seal the bag body or container body,
The heat-pressing portion of the outer film 2 in the heat-sealing portion is a non-welding portion that is not welded to the inner film 1, and the micropores 10 of the inner film 1 of the adhesive-free portion 30 due to intermittent adhesion near the heat seal are the inner film 1 And the outer film 2 are communicated with the gap 4 of the non-welded portion of the outer film 2 in a plastic bag or container. 2. A separate material is formed of the same composite film K as the composite film K, and the outer peripheral portions of the inner film 1 to be adhered are brought into contact with each other and heated and pressed from the outer film 2. 2. The degassing structure according to claim 1, wherein the inner films 1 made of the same material are heat-sealed together to form a bag, and the heating and pressure-contacting portions of the outer films 2 are non-welded portions that are not welded to the inner film 1. . 3. An opening 81 formed through the composite film K in the form of a sheet having a small width in a bag body or a container body of another material.
The degassing structure according to claim 1, wherein the outer peripheral portion of the inner film 1 is heat-sealed. 4. An inner film 1 having an infinite number of fine holes 10 formed on the entire surface thereof and an outer film 2 made of a plastic film made of a material that does not heat-weld to the inner film 1 are bonded together except at least one side end. A composite film that is intermittently weakly adhered with the agent 3 to form a peelable composite film, and the outer peripheral portion of the inner film 1 to be adhered has a plastic material of the same material that is heat-welded to the inner film as a heat seal portion. By heating and press-contacting the heat-sealed portion of the separate material, the inner film of the same material and the plastic of the separate material become a bag body or a container body by heat-sealing each other, The heat-pressing portion of the outer film 2 is a non-welding portion that does not weld to the inner film 1, and the microscopic holes 10 of the inner film 1 of the non-adhesive portion 30 due to intermittent adhesion near the heat seal are formed. , Inner film 1 and outer film 2
1. A degassing structure in a plastic bag or container, which is communicated with the gap 4 of the non-welded portion and in which the outer film 2 is partly peeled off due to an increase in the internal pressure of the bag body or the container body. 5. A separate material is formed of a composite film which is the same as the composite film from which the outer film 2 can be peeled off, and the outer peripheral portions of the inner film 1 to be adhered are brought into contact with each other to make contact with the outer film 2 respectively. When the inner film 1 of the same material is heat-welded to each other to form a bag by heat-sealing, the outer-film 2 and the inner-film 1 are not welded to each other. Item 4
Degassing structure. 6. The composite film K from which the outer film 2 can be peeled off is formed in a small sheet shape, and an outer peripheral portion of the inner film 1 is provided in an opening 81 formed through a bag or container body of another material. The degassing structure according to claim 4, which is heat-sealed. 7. The degassing structure according to claim 1, 2 or 4, wherein the inner surface of the separate material is a plastic non-woven fabric that can be heat-welded to the inner plastic of the composite film. 8. The inner surface of the composite film is formed as a separate material body in which a myriad of fine holes are formed as a plastic film capable of being heat-welded to the inner film and a non-woven fabric is interposed between the outer surface plastic material and the plastic material. Alternatively, the degassing structure according to claim 2 or claim 4 or claim 5.