JPH07329234A - Buffer sheet and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a buffer sheet which is peelable into a plastic part and the other opaque layer, by a method wherein a peelable film is stuck to at least one side face of a cellular part possessing an embossed film and base film made of plastic. CONSTITUTION:In a buffer sheet 6, an embossed film 22, base film 24, peelable film 12 and opaque film 11 are stuck to each other. Since the opaque layer 11 is peeled off easily from the film 12, a plastic part comprised of the films 22, 24, 12 and the opaque layer 11 can be separated easily from each other. Although the film 22 possesses a large number of protusions or embossments and the protrusiond 21 are arranged latticelike state regularly, they are not limitted. The films 22 are stuck together with not only the face where the protrusions 21 are ejected but also the face where the protrusions are not ejected. Hereby, the protrusions 21 form cells together with the film 24 and the cells possess buffer action.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic cushion sheet having air bubbles and a method for manufacturing the same. The cushioning sheet is preferably used for packaging an article, protects the article from impact, keeps the article warm, or insulates it.

[0002]

2. Description of the Related Art Generally, a foamed cushioning sheet has a structure in which a large number of bubbles are formed by bonding an embossed film having a large number of embossments and a base film. BACKGROUND ART Conventionally, a plastic cushioning sheet having air bubbles has been used for packaging or other purposes, and in particular, when transporting articles such as furniture, furniture, and machinery by trucks, etc., a packaging for protecting these articles from impact. It is often used as a material.

However, since the foamed cushioning sheet is made of plastic, when it is used for packing furniture, furniture, machinery, etc., it can be easily torn at the corners of furniture or the like while being transported, or the contents are removed. There was a case where it became completely visible.
In order to solve such inconvenience, a corrugated cardboard or an opaque layer bonded to a foamed cushioning sheet having a basic structure is often used.

[0004]

However, since the foamed cushioning sheet having the opaque layer bonded thereto is difficult to separate into the foamed portion and the opaque layer at the time of disposal, only the plastic foamed portion is collected. It is difficult to reuse as a raw material for recycled plastic. Further, it is difficult to discard only the opaque layer or collect and reuse it as a recycled product such as recycled paper.

[0005]

The present invention has been made to solve the above problems, and provides a cushioning sheet which can be separated into a plastic part and an opaque layer other than the plastic part. The purpose is to do.

That is, according to the present invention, the plastic embossed film on which a large number of embosses are formed, the plastic base film attached to the embossed film, the opaque layer, and the opaque layer are easily formed. A buffer sheet in which a plastic release film attached to the opaque layer is laminated so as to be peeled off, and the embossed film and the base film are provided on at least one surface of the bubble portion, Provided is a cushioning sheet having a release film bonded thereto.

Further, in the present invention, it is preferable that the release film is attached to the embossed film or the base film. Further, it is preferable that the bubble portion further has a plastic top film, and the top film and the base film are bonded to each other with the embossed film sandwiched therebetween. Furthermore, it is preferable that the release film is attached to the top film or the base film.

Further, according to the present invention, a step of forming a bubble portion by adhering a plastic embossed film on which a large number of embosses are formed and a plastic base film, and an opaque layer and a plastic peeling film. A step of laminating a film with the opaque layer so that the opaque layer is easily peeled off, and a step of forming a base material portion, and the release film of the base material portion is provided on at least one surface of the bubble portion. At a temperature of the softening point or higher and 210 ° C. or lower, while being pressure-bonded, by heat fusion, there is a final step of bonding the bubble portion and the base material portion, the method for producing a buffer sheet, Provided.

Further, in the present invention, in the step of forming a bubble portion, (1) a plastic film is wound around an embossing roll having a large number of recesses on its peripheral surface, and the melting point of the film is not lower than 280 ° C. A step of forming the embossed film at a temperature, and (2) the embossed film and the base film wound around the embossing roll on the embossing roll by heat fusion while pressure bonding. It is preferable that the final step further includes a step of preheating the base material portion to a temperature not lower than the softening point of the release film and not higher than 210 ° C.

Further, it is preferable that the final step is carried out on either the embossing roll or a roll separate from the embossing roll. Furthermore, in the final step,
It is preferable to heat-bond the release film of the base material portion to at least one surface of the bubble portion at a temperature of not less than the softening point and not more than 210 ° C. while being pressure-bonded. Further, in the bubble portion forming step, it is preferable that the plastic top film is heat-bonded to the embossed film while being pressure-bonded thereto.

The specific structure of the packaging material of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of a cushioning sheet 6 of the present invention. In the buffer sheet 6, the embossed film 22
The base film 24, the release film 12, and the opaque layer 11 are laminated in this order and bonded together. In this context, “in this order” indicates only a positional relationship, and does not mean a temporal element. Since the opaque layer 11 is easily peeled off from the release film 12, the plastic portion including the embossed film 22, the base film 24, and the release film 12 and the opaque layer 11 not necessarily made of plastic can be easily separated. . In this embodiment, the release film 12 is attached to the base film 24.

The embossed film 22 has a large number of protrusions or embosses 21, and it is preferable that the protrusions 21 are flat as shown in FIG. In FIG. 1, this protrusion 2
1 are regularly arranged in a grid pattern, but the arrangement of the protrusions 21 is not limited. The embossed film 22 has a surface on the side where the projection 21 projects and a surface on the side where the projection 21 does not project, but the base film 24 is attached to the surface on the side where the projection 21 does not project. Thereby, the protrusion 21
Form bubbles together with the base film 24, and the bubbles have a cushioning effect.

The base film 24 has a surface on the side to be bonded to the embossed film 22 and a surface on the side not to be bonded to the embossed film 22.
Is attached to the surface not attached to the embossed film 22. That is, the release film 12 is attached to the base film 24 on the side opposite to the embossed film 22.

FIG. 2 is an explanatory view of the cushioning sheet 6b of the present invention. In the buffer sheet 6b, the opaque layer 11, the peeling film 12, the embossing film 22, and the base film 24 are laminated in this order and attached. In this embodiment, the opaque layer 11 is more easily peeled from the release film 12 as in the embodiment of FIG. 1, but the release film 12 is embossed film 22.
It is attached to the surface of the protrusion 21 of the protruding side. In the cushioning sheet 6b, the air bubbles inside the protrusions 21 formed by the protrusions 21 and the base film 24 not only have a cushioning effect, but also are located outside the protrusions 21 sandwiched between the embossing film 22 and the release film 12. The space also has a buffering effect.

FIG. 3 is an explanatory view of the cushioning sheet 7 of the present invention. In the buffer sheet 7, the top film 23, the embossed film 22, the base film 24, the release film 12, and the opaque layer 11 are laminated in this order,
It is stuck together. In this embodiment, the buffer sheet 6 of FIG. 1 further has a structure in which a top film 23 is attached to the surface of the embossed film 22 on the side where the protrusion 21 projects. That is, the top film 23 and the base film 24 are bonded to each other with the embossed film 22 interposed therebetween. Further, the release film 12 is attached to the base film 24 on the side opposite to the embossed film 22.

In the cushioning sheet 7, the bubbles inside the protrusions formed by the protrusions 21 and the base film 24 not only have a cushioning effect, but also the outside of the protrusions 21 sandwiched between the embossed film 22 and the top film 23. Also has a buffering effect. As shown in FIGS. 1 to 3, the release film is attached to the embossed film or the base film. It does not prevent the release film from being attached to the embossed film and the base film.

The base material portion 1 is formed by laminating the opaque layer 11 and the release film 12 so that the opaque layer 11 can be easily released from the release film 12. It is preferable to manufacture the base material part 1 in an intermediate step of manufacturing the buffer sheet.
In the manufactured cushioning sheet, the release film 1 of the base material portion 1
2 is attached to the embossed film 22, the top film 23, or the base film 24 and integrated with these plastic parts.

The opaque layer 11 may be of any shape as long as it does not melt even when heated to 200 ° C., has a sheet shape, and is easily peeled off from the release film 12, and is appropriately selected depending on the application. You can Examples of such materials include paper sheets containing stretched paper such as kraft paper, corrugated board, high-quality paper, liner or crepe paper, metal foil such as aluminum foil, polyimide resin film, glass fiber,
Nonwoven fabric made of inorganic or organic fiber such as aromatic polyamide fiber; plastic sheet reinforced with glass fiber, carbon fiber etc .; woven fabric of inorganic fiber such as glass, silicon carbide, silicon nitride; aromatic polyamide fiber And the like; woven fabrics made of fiber reinforced plastics such as glass fibers and carbon fibers; and laminated sheets of these. Among them, kraft paper,
Corrugated paper, liner, paper sheet such as high-quality paper, and metal foil such as aluminum foil are preferable. Considering the thickness of the opaque layer,
Corrugated paper and kraft paper are particularly preferable, and kraft paper is most preferable in consideration of toughness.

The thickness of the opaque layer 11 can be appropriately selected depending on the use and the material. For example, when kraft paper is used for packaging, the weight is 10 to 220 g / m.
A thickness of 2 is preferable, and in consideration of durability and flexibility, a thickness of 30 to 100 g / m 2 is more preferable.

Further, the release film 12 is preferably a one-layer or multi-layer film in which the embossing does not cause air escape. However, in the case of bonding to the top film 23 or the base film 24, which does not cause air release of the emboss after forming the emboss, a breathable film can be used.

The material of the release film 12 is preferably a thermoplastic resin, and for example, polyolefins, polyamides, polyesters, polyvinyl chloride, polyvinylidene chloride, etc. can be used. Among them, polyolefins have good airtightness and workability and are inexpensive,
preferable.

As the polyolefin, low density polyethylene, linear low density polyethylene, high density polyethylene,
Homopolymers such as polypropylene; copolymers such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-alkyl acrylate copolymers, ethylene-phenyl acrylate copolymers, ethylene-benzyl acrylate copolymers; of these homopolymers or copolymers Mixtures; further, those obtained by adding a tackifier to these polymers and the like. Among these, particularly preferable are low-density polyethylene, high-density polyethylene, polypropylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, and polyethylene to which a tackifier is added.

The release film 12 is manufactured by a molding method appropriately selected depending on the material. In the case of polyolefins, those manufactured by the T-die method are particularly preferable. Although the thickness of the release film 12 varies depending on the material, it is usually 10 to 100 μm, and practically preferably 10
˜50 μm.

Opaque layer 1 of the base material portion 1 before forming the buffer sheet
The peel strength between 1 and the release film 12 may be such that the peel strength between the opaque layer and the plastic portion after the buffer sheet is formed is such that the opaque layer 11 and the peel film 12 are normally attached. That is, the 180 ° peel strength at a peeling speed of 200 mm / min is 50 mm wide and 0.1 to 2
N, preferably 0.3 to 1 N, and the opaque layer 1
1, the peeling film 12 may have a tensile strength lower than any of the tensile strengths. In the longitudinal and transverse tensile strengths of the opaque layer after forming the cushioning sheet, and the longitudinal and transverse tensile strengths of the plastic part, a range of 0.005-0.03 times the smallest value, particularly Practically, the range is preferably 0.007 to 0.02 times.

The embossed film 22 in the present invention is
It is a plastic film that can be embossed, and does not cause air bubbles to escape after forming a large number of bubbles by heat fusion with the base film 24. The film thickness can be appropriately selected depending on the material used, but is usually 35 to 100 μm, and particularly 50 to 70 μm.
A range of m is preferred. As the embossed film 22 in the present invention, a film formed by either an inflation method or a T-die method may be used.

Top film 23 used in the present invention
Is not particularly limited as long as it is a film that can be heat-bonded while being pressure-bonded to the embossed film 22. The thickness can be appropriately selected depending on the material used, but usually 10 to 1
A range of 00 μm, particularly 35 to 50 μm is preferable. The top film 23 in the present invention may be formed by either the inflation method or the T-die method.

Base film 24 used in the present invention
Is a film that can be heat-sealed while being pressure-bonded to the embossed film 22, and after forming a large number of bubbles by being heat-sealed while being pressure-bonded to the embossed film 22,
It is a film that does not cause air bubbles to escape. further,
When the base film 24 and the base material portion 1 are attached to each other, the base film 24 is a film that can be attached to the release film 12.

The thickness can be appropriately selected depending on the material used, but is usually in the range of 10 to 50 μm, particularly preferably 10 to 40 μm. Base film 24 in the present invention
May be molded by either the inflation method or the T-die method.

Embossing film 22 and top film 2
Both 3 and the base film 24 may use not only a single layer film but also a multilayer film of two or more layers. However, it must be a film that does not cause air release of the emboss after forming a large number of embosses.

The bonding between the embossed film 22 and the base film 24 must be airtight in order to give the packaging material a cushioning effect. Embossed film 2
2. The material of the top film 23 and the base film 24 is preferably a thermoplastic resin, and examples thereof include polyolefins, polyamides, polyesters, polyvinyl chloride, polyvinylidene chloride and the like. Among them, polyolefins are particularly preferable because they have good airtightness, processability and are inexpensive.

As the polyolefin, low density polyethylene, linear low density polyethylene, high density polyethylene,
In addition to homopolymers such as polypropylene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers,
Ethylene-alkyl acrylate copolymer, ethylene-
Examples thereof include phenyl acrylate copolymers, copolymers such as ethylene-benzyl acrylate copolymers, and mixtures thereof. Of these, low density polyethylene, high density polyethylene, polypropylene and linear low density polyethylene are particularly preferable, and low density polyethylene and linear low density polyethylene are more preferable.

The shape of the embossing is mainly a cylinder, but a triangular prism, a prism, a polygonal prism such as a pentagonal prism or a hexagonal prism, a cone,
Triangular pyramid, pyramid, polygonal pyramid such as pentagonal and hexagonal pyramid, truncated cone, triangular pyramid, truncated pyramid, polygonal pyramid such as pentagonal pyramid and hexagonal pyramid, hemisphere, egg shape, spheroid, etc. You can Also, a plurality of these shapes may be combined.

The height of the embossing is preferably in the range of 1 to 20 mm and the bottom area is 0.1 to 1.5 cm 2. Further, it is preferable that the embosses are arranged on the entire surface of the embossed film 22 at intervals of 0.5 to 20 mm.

Next, the manufacturing method of the present invention will be described. The base material part 1 is produced by the method described in Japanese Patent Publication No. 54-20227, for example. That is, the base material part 1 is
About 2 parts of the resin that constitutes the release film 12 is formed on the opaque layer.
It may be extruded at 00 ° C, laminated and subjected to corona discharge treatment. The resin that constitutes the release film 12 is approximately polyethylene, a resin obtained by adding a tackifier to polyethylene (for example, Quinton C-200S, a trade name of Nippon Zeon Co., which has 1,3-pentadiene as a main component). Examples include tacky polyethylene added with 5% and a resin having heat-sensitive adhesiveness (for example, hot-melt type ethylene-vinyl acetate copolymer). Also, a dry laminating adhesive is applied, for example, at 0.3 to 0.5 g per 1 m 2,
You may adhere an opaque layer and a peeling film.

In the above lamination, the resin extrusion molding temperature is set to about 200 ° C. because the extrusion temperature is, for example, about 30 ° C.
This is because the release film 12 adheres completely to the opaque layer 11 when the temperature is as high as 0 ° C. On the other hand, when the extrusion temperature is relatively low at about 170 ° C., there is a problem with the resin extrudability. is there.

The cushioning sheet 6 shown in FIG. 1 has a bubble portion 3 formed of an embossed film 22 and a base film 24.
Of the release film 12 of the base material portion 1 on at least one surface of the
The softening point of the release film 12 or higher while pressing the side of
It is manufactured by heat-sealing at a temperature of ℃ or less and bonding the bubble portion 3 and the base material portion 1 together.

In a preferred embodiment of this manufacturing method,
(1) The embossing 21 is formed on the plastic film to form the embossing film 22. (2) At the same time when the embossing 21 is formed, the base film 24 is wound around the embossing film 22, and (3) the embossing is performed. On the roll, the embossed film 22 and the base film 24,
Forming the bubble portion 3 by heat fusion while pressure bonding, (4) wrap the base material portion 1 preheated to the softening point of the release film 12 or higher on the bubble portion 3, and (5) on the embossing roll. The bubble portion 3 and the base material portion 1 are manufactured by a process of heat-bonding while pressure-bonding.

A more specific example of the manufacturing method will be described with reference to FIGS. FIG. 5 illustrates a process of manufacturing the buffer sheet 6 from the film 22 ′ (film before embossed film formation), the base film 24 and the base material portion 1. The film 22 'and the base film 24 used here may be an inflation film original fabric, or instead of the inflation film original fabric,
A T-die film stock may be used. The inflation film is formed by the film forming process shown in FIG.

In FIG. 5, the base material portion 1 is wound around the base material portion original roll 301 such that the surface of the release film 12 is on the inside. The base material portion 1 may be directly sent to the embossing roll 109, but preferably via the roll 104,
Preheated by the heating roll 105, the embossing roll 109
Sent to. The temperature of the heating roll 105 is the opaque layer 11
In order to make the peeling film 12 peel easily,
It suffices that the release film 12 is maintained at a temperature of not less than the softening point and not more than 210 ° C., but a preferable range is the release film 1
It is in the range of not less than the softening point of 2 and not more than 10 ° C. higher than its melting point.

On the other hand, it is preferable that the film 22 ′ before becoming the embossed film 22 is preheated before being sent to the embossing roll 109. For example, as shown in FIG. 5, via the roll 106, preheated by the heating roll 107,
It is sent to the embossing roll 109 via the roll 108. The temperature of the heating roll 107 is set to the embossed film 22.
It suffices that the temperature is maintained above the softening point of 280 ° C. and below, but the preferred range is above the softening point of the embossed film 22 and below the melting point thereof by 10 ° C. Each of the heating rolls 105 and 107 may be one roll, but it is preferably two or more rolls so as to be sufficiently preheated, and more preferably three rolls in practice.

The base film 24 is the embossing roll 1
It is preferable to be preheated before being sent to 09, and for example, it is preheated by the heating roll 120 and sent to the embossing roll 109 via the roll 119. Heating roll 1
The temperature of 20 may be maintained above the softening point of the base film 24, but a preferable range is the base film 2
4 is the softening point or higher and is in the range of a temperature 10 ° C. higher than the melting point or lower. The number of rolls of the heating roll 120 is
Although the number may be one, it is preferable that the number is two or more, and practically three, so that sufficient preheating can be performed.

In the embossing roll 109, the film 22 'before embossing is heated while being heated by a vacuum pump.
A large number of embosses 21 are formed on the film 22 ′ by suctioning at a vacuum degree of 0 to 100 hPa to form the embossed film 22. The embossed film 22 and the base film 24 are pressure-bonded by the pressure-bonding roll 121, and are heat-fused on the embossing roll 109 to form the bubble portion 3.
After forming the bubble portion 3 or simultaneously with the formation of the bubble portion 3, the bubble portion 3 and the base material portion 1 are pressed by the pressure roll 110.
The embossing roll 1 so that the surface of the base film 24 of the bubble portion 3 and the surface of the release film 12 of the base material portion 1 are in contact with each other.
It is heat-bonded while being pressed to 09. Then, the cooling roll 11
1, the buffer sheet 6 is formed by cooling while being pressed against the embossing roll 109.

Here, the temperature of the embossing roll 109 is 2
When the temperature exceeds 80 ° C, the embossed film 21 has an embossed film 21.
Is not formed well, the temperature of the embossing roll 109 is 280 ° C. or lower, and since the embossing is not formed below the melting point of the film used for the embossed film, it is usually higher than the melting point of the film.
It is heated to a temperature range of 0 ° C or lower. The preferred range from the shape of the emboss is not less than the melting point of the film and not more than 70 ° C. higher than the melting point, and more preferably not less than 10 ° C. higher than the melting point of the film and not less than the melting point. The temperature is not higher than 50 ° C.

The temperature of the pressure bonding roll 110 may be any temperature at which the embossing film 22, the base film 24 and the base material portion 1 can be heat-bonded while being pressure-bonded, and usually,
The melting point is not lower than the melting point and is not higher than 70 ° C. higher than the melting point, and the preferable range is not lower than the melting point of the embossed film 22 and not higher than 30 ° C. higher than the melting point. The buffer sheet 6 formed by the embossing roll 109 is further cooled via the roll 112.

The inflation film original fabric which may be used in the manufacturing process of FIG. 5 is molded by the inflation film molding process shown in FIG. In FIG. 4, the raw material resin is extruded from the extruder to the die 201 in a molten resin state by heat, and air is blown from below the die 201 to air-cool to form the tubular film 2, and the adjusting plate 401 , Roll 101a,
The film 2 is flattened by 101b, and the film 2 is divided into the film 2a and the film 2b by the slit cutter 402 via the roll 102.
The roll a is rolled through the roll 103a and the roll 2b is rolled through the roll 103b.
The temperature at the exit of the die 201 is preferably 150 to 210 ° C.

FIG. 6 illustrates a process of manufacturing the buffer sheet 6 from the film 22 ', the base film 24 and the base material portion 1. It differs from FIG. 5 in that the film 22 ′ and the base film 24 are manufactured by a T-die film molding line. The base material part 1 is a base material part roll 301
The part to be sent from the to the embossing roll 109 and the part through which the embossing film 22 passes are the same as in the case of FIG.
The film 22 'is extruded from the T-die 202,
The base film 24 is extruded from the T die 203 and sent to each embossing roll 109. T-die 20
The temperature at the outlet of 2,203 is usually 210 to 250 ° C., and practically preferably 230 to 250 ° C.

In the embossing roll 109, the embossing 21 is formed in the same manner as in the case of FIG. 5, the bubble portion 3 is formed from the embossing film 22 and the base film 24, and the bubble portion 3 and the base material portion 1 are formed. Heat-bonding while crimping. Next, the cushioning sheet 6 is formed by cooling while being pressed against the embossing roll 109 by the cooling roll 111. The temperature of the embossing roll 109 and the temperature of the pressure bonding roll 110 are
This is the same as the case of FIG. The cooling roll 111 is cooled by partially immersing the cooling water in the roll 111. The buffer sheet 6 formed by the embossing roll 109 further passes through the roll 112 and is sufficiently cooled by the cooling roll 113. In addition, from the T die 202 of FIG.
09 part and T die 203 to emboss roll 1
The film may be supplied in the form of a raw material to either one of the parts to 09 and sent to the embossing roll via the heating roll.

Next, an example of a method of manufacturing the buffer sheet 6b of FIG. 2 will be described. First, the bubble portion 3 is manufactured. For example, it is manufactured by a method in which the base material portion 1 is not supplied in the steps shown in FIGS. Then, by the process shown in FIG. 7, heating is performed so that the embossed film 22 side of the bubble portion 3 and the release film 12 side of the base material portion 1 face each other by heating. That is, with the heating roll 118, the emboss 2 of the bubble portion 3
1 and the release film 12 of the base material part 1 are pressure bonding rolls 11
The buffer sheet 6b is formed by being heat-bonded while being pressure-bonded by 4. The temperature of the heating roll 118 and the pressure bonding roll 114 may be the temperature at which the bubble portion 3 and the release film 12 can be heat-sealed. A preferable range is a temperature that is equal to or higher than the melting point of the release film 12 and is equal to or lower than a temperature that is 30 ° C. higher than the melting point. In addition, the heating roll 118 and the pressure bonding roll 11
It is more preferable to preheat the base material part 1 or the bubble part 3 before being sent to

The cushioning sheet 6 of FIG. 1 can also be manufactured by forming the bubble portion 3 by the same process as that of FIG. 7 and then bonding the base material portion 1 to the base film 24 side.

Next, a method of manufacturing a buffer sheet having a structure in which the bubble portion 3b further having the top film 23 and the base material portion 1 are bonded together will be described. First, after the bubble portion 3 is manufactured as described above, (1) the top film 23 is wound so as to come in contact with the embossed film 22 of the bubble portion 3, and (2) the bubble portion 3 and the top are placed on the pressure bonding roll. After the bubble portion 3b is manufactured by the process of heat-bonding the film 23 with pressure bonding, the bubble portion 3b and the base material portion 1 are pressure-bonded on the heating roll and heat-bonded to each other to thereby form the buffer sheet 7 of FIG. Can be manufactured.

One embodiment of the method of manufacturing the bubble portion 3b will be further described with reference to FIG. The top film 23 is a roll 115
Is heated by the heating roll 116 and sent to the heating roll 118. The temperature of the heating roll 116 is maintained above the softening point of the top film 23, but the preferred range is above the softening point of the top film 23,
It is in the range of a temperature 10 ° C. higher than the melting point or lower. The number of rolls of the heating roll 116 does not have to be one, but it is preferably three so that it can be preheated sufficiently. on the other hand,
The bubble portion 3 is preferably preheated before being sent to the heating roll 118 and the pressure roll 114.

In the heating roll 118, the side of the bubble portion 3 on the embossing 21 side and the top film 23 are the pressure roll 11
While being pressure-bonded by 4 and heat-sealed, the bubble portion 3b is formed. The temperatures of the heating roll 118 and the pressure bonding roll 114 are
The temperature may be any temperature at which the bubble portion 3 and the top film 23 can be heat-sealed. A preferred range is a temperature equal to or higher than the melting point of the top film 23 and equal to or lower than a temperature 30 ° C. higher than the melting point.

Next, the bubble portion 3 manufactured in this way
b and the base material portion 1 are bonded by heat fusion while being pressure bonded by the method shown in FIG. 9 so that the base film of the bubble portion 3b is bonded to the release film 12 of the base material portion 1, and thus the buffer sheet 7 Can be manufactured. FIG. 9 is similar to FIG. 7, and since the bubble portion 3b is used instead of the bubble portion 3,
The only difference is that the cushioning sheet 7 is manufactured instead of the cushioning sheet 6b. By attaching the release sheet 12 of the base material portion 1 to the top film 23 of the bubble portion 3b,
Buffer sheets of different embodiments can be manufactured.

Further, the cushioning sheet 7 can be manufactured by heat-bonding the embossed film 22 of the cushioning sheet 6 and the top film 23 while pressing them.

As a preferred embodiment of the manufacturing method, (1) the top film 23 is provided on the buffer sheet 6 having a structure in which the base material portion 1 is bonded only to the base film 24 side.
Is wound so that the embossed film 22 side of the buffer sheet 6 and the top film 23 come into contact with each other, and (2)
On the pressure-bonding roll, the buffer sheet and the top film 23
Is heat-bonded while crimping.

As a more specific embodiment, FIG.
Will be described. FIG. 10 shows a process of manufacturing the buffer sheet 7 by bonding the top film 23 to the buffer sheet 6. The top film 23 is preheated by the heating roll 116 via the roll 115 and sent to the heating roll 118. The temperature of the heating roll 116 is maintained at the softening point of the top film 23 or higher, but the preferable range is the softening point of the top film 23 or higher and 10 ° C. or higher higher than the melting point thereof. The number of rolls of the heating roll 116 does not have to be one, but it is preferably three so that it can be preheated sufficiently. On the other hand, the buffer sheet 6 is preferably preheated before being sent to the heating roll 118 and the pressure roll 114.

In the heating roll 118, the embossing 21 side of the buffer sheet 6 and the top film 23 are heat-bonded while being pressure bonded by the pressure roller 114 to form the buffer sheet 7. The temperature of the heating roll 118 and the pressure bonding roll 114 may be a temperature at which the buffer sheet 6 and the top film 23 can be heat-sealed, but a preferable range is equal to or higher than the melting point of the top film 23, and 30 is higher than the melting point. It is in the range of not higher than ℃. The formed buffer sheet 7 is further cooled and wound up by a winding machine.

Further, in FIG. 10, the top film 2
Since 3 is supplied in the form of a raw fabric, the manufacturing method is not particularly limited, and either an inflation film or a T-die film may be used. Further, the film may be directly sent from the T die to the heating roll 118 in the portion of the top film 23 in FIG.

Next, the base material portion 1 is the bubble portion 3 or the bubble portion 3b.
A method of manufacturing a buffer sheet having a structure in which the both sides of the buffer sheet are laminated will be described. That is, (1) a step of manufacturing a buffer sheet having a structure in which the base material portion 1 is bonded to one side of the bubble portion 3 or the bubble portion 3b; and (2) the buffer sheet and the base material portion 1. It is manufactured by a process including a process of heat-bonding while crimping.

Specifically, a buffer sheet having a structure in which the base material portion 1 is bonded to one side of the bubble portion 3 or the bubble portion 3b is manufactured by the method described above, and then the buffer sheet and the base sheet are formed. The material part 1 and the material part 1 are manufactured by going through the same steps as those shown in FIG. 7 or 9. In this case, the bubble portion 3 in FIG. 7 means the buffer sheet 6 or the buffer sheet 6b,
The bubble portion 3b in FIG. 9 means the buffer sheet 7.

[0061]

In the buffer sheet of the present invention, the opaque layer such as kraft paper is easily peeled off from the release film. Therefore, when discarding, the plastic part containing the release film is separated from the opaque layer and reused as recycled plastic. can do. Furthermore, when the opaque layer can be recycled, the opaque layer can be collected and reused as a recycled product such as recycled paper. In addition, the method for producing the buffer sheet of the present invention is a method that can be produced from an inflation film original fabric or a T die film original fabric, and can also be produced directly from a T die film forming line, so that it can be used as a film forming method. The cushioning sheet can be manufactured independently.

[0062]

EXAMPLES Examples of the cushioning sheet and the manufacturing method thereof according to the present invention will be shown below, but the scope of the present invention is not limited to the examples shown below.

[Example 1] A peeling speed of 20 was used as a base material portion.
The 180 ° peel strength at 0 mm / min is 50 mm in width of 0.
The weight is 50g / m2 (thickness 70μ
m) kraft paper and a polyethylene film having a thickness of 35 μm are bonded together, and the polyethylene inflation film molded by the molding method shown in FIG. 4 is used as the embossing film and the base film. A buffer sheet was manufactured by the manufacturing method shown. The embossed film used had a thickness of 60 μm, and the base film had a thickness of 30 μm. The manufactured cushioning sheet has no air vent after embossing, and the tensile strength in the width of 50 mm is 200 N in the longitudinal direction of the kraft paper part and 90 N in the lateral direction, and 88 N in the longitudinal direction of the plastic part and in the lateral direction. It was 59N. The peel strength between the kraft paper portion and the plastic portion at a peeling speed of 200 mm / min and a width of 50 mm is 0.79 N in the longitudinal direction and 0.69 N in the lateral direction. It was easily peeled off from the other plastic parts.

[Example 2] The same material as in Example 1 was used as the base material, and a polyethylene T-die film was used as the embossing film and the base film to produce directly from the T-die film forming line. A buffer sheet was manufactured by the manufacturing method shown. The thickness of the embossed film was 60 μm, and the thickness of the base film was 30 μm. The manufactured cushioning sheet had no air escape after embossing, and the tensile strength in the width of 50 mm showed almost the same value as in Example 1 in the kraft paper portion,
The plastic part showed a value almost equal to that of Example 1.
The peeling strength between the kraft paper portion and the plastic portion at a peeling speed of 200 mm / min and a width of 50 mm was 0.82 N in the longitudinal direction and 0.71 N in the lateral direction. It was easily peeled off from the other plastic parts.

[Example 3] Base material portion, embossed film,
And, as the base film, the one of Example 1 is used, and as the top film to be attached to the embossed film,
Using a polyethylene inflation film having a thickness of 40 μm formed by the forming method shown in FIG.
The cushioning sheet was manufactured by the manufacturing method including the steps from step 1 to step 10 in FIG. The produced cushioning sheet had no air escape after formation of bubbles (embossing), and the tensile strength in the width of 50 mm showed almost the same value as in Example 1 in the kraft paper portion, and 98 N in the longitudinal direction of the plastic portion. It was 63 N in the lateral direction. Also, peeling speed 200 mm / min, 50
The peel strength between the kraft paper part and the plastic part in the mm width is 0.88 N in the longitudinal direction and 0.75 N in the lateral direction, and the manufactured cushioning sheet can be easily separated from the kraft paper part from other plastic parts. Peeled off.

[0066]

INDUSTRIAL APPLICABILITY The buffer sheet of the present invention can be reused as recycled plastic because it can be separated into a plastic part and an opaque layer when discarded, and the opaque layer is a recyclable material. In this case, the opaque layer can be reused as a recycled product such as recycled paper.

In addition, the method for producing the cushioning sheet of the present invention is a method that can be produced from an inflation film original fabric or a T die film original fabric, or directly from a T die film molding line. From either T-die film,
A cushioning sheet can be manufactured.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the structure of a cushioning sheet of the present invention.

FIG. 2 is an explanatory diagram of one embodiment of the structure of the cushioning sheet of the present invention.

FIG. 3 is an explanatory view of one embodiment of the structure of the cushioning sheet of the present invention.

FIG. 4 is an explanatory view of an embodiment of a method for forming a blown film original fabric.

FIG. 5 is an explanatory view of one embodiment of a process for producing a cushioning sheet of the present invention using a blown film original fabric or the like.

FIG. 6 is an explanatory view of one embodiment of a process for producing a buffer sheet by directly producing a film from a T die film forming line.

FIG. 7 is an explanatory diagram of an embodiment of a step of bonding the bubble portion 3 and the base material portion 1 together.

FIG. 8 is an explanatory diagram of an embodiment of a process of manufacturing the bubble portion 3b.

FIG. 9 is an explanatory diagram of an embodiment of a step of bonding the bubble portion 3b and the base material portion 1 together.

FIG. 10 is an explanatory diagram of an embodiment of a step of bonding the buffer sheet 6 and the top film 23 together.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base material part 2 2a 2b Film 3 3b Air bubble part 6, 6b, 7 Buffer sheet 11 Opaque layer 12 Release film 21 Embossing 22 Embossing film 23 Top film 24 Base film 101a, 101b, 102, 103a, 103b, 1
04, 106, 108, 112, 115, 119 rolls 105, 107, 116, 117, 118, 120 heating rolls 110, 114, 121 pressure bonding rolls 109 embossing rolls 111, 113 cooling rolls 201 dies 202, 203 T dies 301, 302 Base material roll 401 Adjusting plate 402 Slit cutter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location B32B 31/20 7148-4F (72) Inventor Takao Wada 1-2-2 Kamishinjo, Higashiyodogawa-ku, Osaka-shi, Osaka No. 5 In Keiwa Shoko Co., Ltd. (72) Inventor Koji Hiraoka 8-1 Goi Minami Coast, Ichihara City, Chiba Ube Industries Ltd. Chiba Petrochemical Factory (72) Inventor Kazuki Yoneda Goi Minami Kaigan, Ichihara City, Chiba No. 8-1 Inside Ube Industries, Ltd. Chiba Petrochemical Factory

Claims (9)

[Claims] 1. A plastic embossed film having a large number of embosses formed thereon, a plastic base film attached to the embossed film, an opaque layer, and an opaque layer so that the opaque layer is easily peeled off. A buffer sheet laminated with a plastic release film attached to an opaque layer, wherein the release film is attached to at least one surface of a bubble portion having the embossed film and the base film. A cushioning sheet characterized by being. 2. The buffer sheet according to claim 1, wherein the release film is attached to the embossed film or the base film. 3. The bubble portion further has a plastic top film, and the top film and the base film are bonded together with the embossed film sandwiched therebetween. The buffer sheet described. 4. The buffer sheet according to claim 3, wherein the release film is attached to the top film or the base film. 5. A step of forming a bubble portion by adhering a plastic embossed film on which a large number of embosses are formed and a plastic base film, the opaque layer and the plastic release film, A step of forming the base material part by laminating the layers so that they are easily separated, and the release film of the base material part on at least one surface of the bubble part, the softening point of the release film or higher 210
A method of manufacturing a buffer sheet, comprising a final step of bonding the bubble portion and the base material portion by heat-bonding while pressure-bonding at a temperature of ℃ or less. 6. The step of forming a bubble portion comprises: (1) winding a plastic film around an embossing roll having a large number of recesses on its peripheral surface to obtain a film having a melting point of 2 or higher.
A step of forming the embossed film at a temperature of 80 ° C. or lower, and (2) heat-bonding the embossed film and the base film wound around the embossing roll on the embossing roll while pressure bonding. And a step of forming a bubble portion, and the final step further comprises a step of preheating the base material portion to a temperature not lower than the softening point of the release film and not higher than 210 ° C. The method for manufacturing the buffer sheet according to claim 5. 7. The method for producing a buffer sheet according to claim 5, wherein the final step is performed by either the embossing roll or a roll separate from the embossing roll. 8. In the final step, the release film of the base material portion is pressure-bonded to at least one surface of the bubble portion, and heat fusion is performed at a temperature of not less than the softening point and not more than 210 ° C. The method for producing a buffer sheet according to claim 5, 6, or 7. 9. A plastic top film is added to the embossed film in the bubble portion forming step.
It heat-bonds, press-bonding and it is characterized by the above-mentioned.
The method for producing a buffer sheet according to any one of 1.