阅读说明：本技术 薄膜的立体成型方法、薄膜成型体的制造方法、以及薄膜成型体 (Method for three-dimensional molding of film, method for producing film molded body, and film molded body ) 是由 田中宏树 安海隆裕 石坂公一 畠源英 宍户翔太朗 于 2019-01-07 设计创作，主要内容包括：本发明提供一种立体成型方法、薄膜成型体的制造方法、以及薄膜成型体,其能够实现加工时间的缩短以及能量消耗的降低,并且不需要变更现有设备的设计,就能够容易地对内侧薄膜部实施立体成型。在薄膜的立体成型方法中,将具有第1层(21)以及伸长比第1层更小的第2层(22)的至少1片内侧薄膜部(30)在2片外侧薄膜部(30)之间以相对于外侧薄膜部(30)而呈非固定的状态来进行配置,从而形成出薄膜重叠部位(50),通过沿着厚度方向而对薄膜重叠部位(50)实施冷压缩成型,由此在薄膜重叠部位(50)处使内侧薄膜部(20)朝向所述第2层(22)侧伸出。(The invention provides a three-dimensional molding method, a method for manufacturing a film molded body, and a film molded body, which can realize the reduction of processing time and energy consumption, and can easily perform three-dimensional molding on an inner film part without changing the design of the existing equipment. In a method for three-dimensional molding of a film, at least 1 piece of inner and outer film portions (30) having a 1 st layer (21) and a 2 nd layer (22) having a smaller elongation than the 1 st layer are arranged between 2 pieces of outer film portions (30) in a non-fixed state with respect to the outer film portions (30) to form a film overlapping portion (50), and cold compression molding is performed on the film overlapping portion (50) along the thickness direction to thereby project the inner film portion (20) toward the 2 nd layer (22) side at the film overlapping portion (50).)

1. A method for three-dimensional forming of a film is characterized in that,

at least one inner film portion having a 1 st layer and a 2 nd layer having a smaller elongation than the 1 st layer is disposed between 2 outer film portions in a non-fixed state with respect to the outer film portions to form a film overlapping portion,

cold compression molding is performed on the film overlapping portion along the thickness direction, whereby the inner film portion is caused to protrude toward the 2 nd layer side at the film overlapping portion.

2. The method of claim 1, wherein the step of forming the film includes the steps of,

the compression molding ratio of the inner film portion in the thickness direction is: the thickness of the inner film part is 20% or more.

3. The method of claim 1 or 2, wherein the step of forming the film includes the steps of,

the compression molding ratio of the inner film portion and the 2 outer film portions in the thickness direction is: the total thickness of the inner film part and the 2 outer film parts is more than 20%.

4. A method for producing a film molded body, which comprises forming a crotch part between at least 1 sheet-inside film part and 2 sheet-outside film parts, the film parts having a 1 st layer and a 2 nd layer having a smaller elongation than the 1 st layer,

it is characterized in that the preparation method is characterized in that,

cold compression molding is performed on the outer film portion along the thickness direction at a film overlapping portion in the crotch portion, whereby the inner film portion is caused to protrude toward the 2 nd layer side at the film overlapping portion.

5. The method for producing a film forming body according to claim 4,

the inner film portion includes 2 or more sheets, and at least 2 sheets of the 2 or more inner film portions are arranged in the crotch portion in a manner that: the 2 nd layers are opposed to each other.

6. A film molded body having a 1 st layer and at least one inner film portion extending from a 2 nd layer smaller than the 1 st layer, a crotch portion being formed between 2 outer film portions,

it is characterized in that the preparation method is characterized in that,

the inner film portion in the crotch portion has a protruding portion protruding toward the 2 nd layer side at a film overlapping portion.

7. The film forming body according to claim 6,

the inner film portion includes 2 or more sheets, and at least 2 sheets of the 2 or more inner film portions are arranged in the crotch portion in a manner that: the 2 nd layers are opposed to each other.

Technical Field

The present invention relates to a method for three-dimensional molding of a film, a method for producing a film molded body, and a film molded body.

Background

Conventionally, in a film molded body such as a bag made of a film, three-dimensional molding such as stretching a part of the film toward one of the front and back sides of the film is performed, and as a method for three-dimensional molding of such a film, there is generally known: a method of forming a protrusion having a predetermined shape by hot press forming a film and then cooling the film (see, for example, patent document 1).

Further, there are known: in such a film molded body such as a bag, a film overlapping portion in which a plurality of film portions are arranged to overlap each other is formed in a crotch portion (connecting portion) or the like formed in a bottom portion or a side portion of the film molded body (for example, see patent document 2).

Disclosure of Invention

In the film molded body such as a bag disclosed in patent document 2, it is desirable that the projecting portion is formed in an inner film portion located on the inner side among a plurality of film portions constituting the film overlapping portion.

However, when the protruding portion is to be formed on the inner thin film portion by the hot press forming method described in patent document 1, if the press forming is performed in a state where the outer thin film portion and the inner thin film portion are arranged in an overlapping manner, the outer thin film portion and the inner thin film portion are thermally welded by heat generated during the processing, and therefore, the protruding portion needs to be formed on the inner thin film portion in a state before the outer thin film portion and the inner thin film portion are arranged in an overlapping manner.

In this case, it is necessary to provide, in the middle of the existing apparatus for molding the film molded body: in the apparatus for forming the extension portion in the inner thin film portion or in the section for cooling the inner thin film portion in the state before the outer thin film portion and the inner thin film portion are arranged to overlap each other, there is a problem that a significant design change is required for the conventional apparatus.

In addition, in the method of hot press forming described in patent document 1, since it takes a cooling time after the hot press forming, the working time becomes long, and since heating or cooling is required, there is a problem of the method of hot press forming itself that the energy consumption is large.

Accordingly, an object of the present invention is to solve the above problems and to provide a method for three-dimensionally forming a film, a method for producing a film-formed body, and a film-formed body, which can realize reduction in processing time and energy consumption and can easily perform three-dimensional forming of an inner film portion without changing the design of existing equipment.

The method for three-dimensional molding of a film according to the present invention solves the above technical problem by: at least one inner film portion having a 1 st layer and a 2 nd layer having a smaller elongation than the 1 st layer is arranged between 2 outer film portions in a non-fixed state with respect to the outer film portions to form a film overlapping portion, and the film overlapping portion is subjected to cold compression molding in a thickness direction, whereby the inner film portion is caused to protrude toward the 2 nd layer side at the film overlapping portion.

The method for producing a film molded article of the present invention solves the technical problem by: the method for producing a film molded body comprises forming a crotch portion between 2 inner film portions by at least 1 inner film portion having a 1 st layer and a 2 nd layer having a smaller elongation than the 1 st layer, and cold compression molding the outer film portion along the thickness direction at a film overlapping portion in the crotch portion, thereby extending the inner film portion toward the 2 nd layer side at the film overlapping portion.

The film molded article of the present invention solves the above technical problem by: the film forming body is provided with a 1 st layer and at least one inner film part extending out of a 2 nd layer smaller than the 1 st layer, wherein a crotch part is formed between the 2 outer film parts, and the inner film part in the crotch part is provided with an extending part extending out towards the 2 nd layer side at a film overlapping part.

In addition, "cold" in the present specification means: a temperature region including normal temperature (20 ℃. + -. 15 ℃) and lower than the Vicat softening temperature of the constituent materials of the inner thin film portion and the outer thin film portion.

Various indexes exist as indexes indicating "elongation" of each layer of each thin film portion, but examples thereof include elastic modulus, young's modulus, elongation at yield, and elongation at break.

The term "inner thin film portion" used in the present specification means: the film portion disposed on the inner side when the plurality of film portions are overlapped and compression-molded is not limited to the film portion disposed on the inner side in a state of the film molded body.

Similarly, the term "outer thin film portion" used in the present specification means: the film portion disposed on the outer side when the plurality of film portions are stacked and compression-molded is not limited to the film portion disposed on the outer side in a state of the film molded body.

According to the present invention, cold compression molding is performed on the film overlapping portion in the thickness direction, so that: the thermal fusion between the thin film portions is likely to occur when the three-dimensional processing is performed by the hot press forming, and not only can the processing time be shortened and the energy consumption be reduced, but also the following effects can be achieved as compared with the case where the three-dimensional processing is performed by the hot press forming.

That is, in the present invention, by cold compression molding the film overlapping portion obtained by arranging the inner film portion between the outer film portions in an unfixed state along the thickness direction, the outer film portion can be protruded toward the 2 nd layer side without leaving any three-dimensional processing mark on the outer film portion or with leaving only a small three-dimensional processing mark on the outer film portion. Accordingly, the inner film portion can be easily three-dimensionally processed even after the film overlapping portion is formed, for example, after the bag is manufactured, and therefore, as a post-process of the existing facility, a facility for three-dimensionally processing the inner film portion may be provided, and there is no need to change the design of the existing facility.

Here, regarding the protrusion phenomenon that occurs when the inner film portion having the 1 st layer and the 2 nd layer protruding smaller than the 1 st layer is cold-compressed in the thickness direction, although the mechanism thereof is not clear, it can be considered that the following factors are caused: in the action when the thickness of the inner film portion is restored after the compressive force is removed, the 1 st layer having a relatively large elongation is also largely restored, and the 2 nd layer having a relatively small elongation is also only slightly restored.

In addition, as described above, when cold compression molding is performed in the thickness direction, no three-dimensional processing mark remains in the outer thin film portion, or only a small three-dimensional processing mark remains in the outer thin film portion, and the protrusion phenomenon occurs in the inner thin film portion, which is considered to be because: when the film overlapping portion is compression-molded by the compression tool from the outside of the outer film portion, the friction between the film portions is smaller than the friction between the outer film portion and the compression tool, and thus the inner film portion is stretched in the planar direction of the film and is compressed greatly in the thickness direction than the outer film portion.

Drawings

Fig. 1 is a plan view of a bag according to an embodiment of the present invention.

Fig. 2 is a sectional view taken along the thickness direction at the line a-a of fig. 1.

Fig. 3 is a cross-sectional view showing an example of a method of three-dimensional molding of a film.

Fig. 4 is a photograph of a bag having an extension portion formed in an inner film portion.

Fig. 5 shows the test results of the test performed to confirm the appropriate compression molding ratio.

Fig. 6 is a cross-sectional view showing a modification of the film overlapping portion.

Fig. 7 is an explanatory view schematically showing a modification of the crotch portion.

Fig. 8 is an explanatory view schematically showing a modification of the crotch portion.

Detailed Description

Hereinafter, a bag 10 as a film molded body according to an embodiment of the present invention will be described with reference to the drawings.

First, as shown in fig. 1 and 4, the bag 10 is formed into a bag shape by heat-welding the outer edge of a film as a material, and accommodates a content liquid such as a detergent or a shampoo.

As shown in fig. 1 and 2, a crotch portion (connecting portion) 40 is formed at the bottom of the pouch 10, and the crotch portion (connecting portion) 40 is formed by disposing the 2 inner film portions 20 between the 2 outer film portions 30.

In the present embodiment, as is apparent from fig. 4 and 7(a), in the crotch unit 40, the 2-piece inside film portion 20 includes: a turn-back part 24 connected at the upper end thereof. Each outer film portion 30 is locally heat-welded to the opposing inner film portion 20 by heat-welding the 1 st layer 21 of the inner film portion 20 and the 1 st layer 31 of the outer film portion 30 at the heat-welded portion 70 on the lower side (bottom side) thereof.

As shown in fig. 2, each inner film portion 20 is formed as a laminated film by laminating and bonding a 1 st layer 21 and a 2 nd layer 22 having a smaller elongation than the 1 st layer 21.

As shown in fig. 2 and 3, the 2-piece inner side film portion 20 is arranged such that: the 2 nd layers 22 are opposed to each other when compression molding is performed or when the bag 10 is folded.

As shown in fig. 2, each inner film portion 20 has a protruding portion 23 protruding from the 1 st layer 21 side toward the 2 nd layer 22 side at a film overlapping portion 50 in the crotch portion 40 where the film portions 20 and 30 are disposed in an unfixed state.

In the present embodiment, as shown in fig. 4, the extension portions 23 are formed in a plurality of lines in a direction (vertical direction in the present embodiment) of the inner film portion 20 intersecting the fold line 25 of the fold portion 24. In addition, the protruding portion 23 is formed by: the positions where the inner film portions 20 overlap each other when the crotch portion 40 is folded. This is caused by a method of molding the protruding portion 23, and a method of forming the protruding portion 23 will be described later.

The specific shape of the protruding portion 23 may be any shape limited to the linear shape described above, and the number of the protruding portions 23 may be 1.

The extension portion 23 can function as a support for the crotch portion 40 in a state where the crotch portion 40 is opened when the crotch portion 40 is spread, and thus the opened state of the crotch portion 40 can be maintained. In particular, in the self-standing bag of the present embodiment, if the opened state of the crotch portion 40 is maintained, the state of the inflated bag 10 is difficult to return before the filling of the contents, and therefore, the opening property and the opened state of the bag 10 can be maintained. These linear extending portions 23 extend toward the bottom side (outside) in a state where the crotch portion 40 is expanded.

As shown in fig. 2, the outer film portion 30 is formed as a laminated film by laminating and bonding a 1 st layer 31 and a 2 nd layer 32 having a smaller elongation than the 1 st layer 31.

As shown in fig. 2, each outer thin film portion 30 is arranged such that: layer 2 32 is located further to the outside of the bag 10 than layer 1 31.

When the bag 10 is manufactured, the 1 st layers 31 of the outer film portions 30 on the front and back sides are thermally welded to each other except for the bottom portion (upper portion and side portion) of the bag 10.

Specific materials of the 1 st layers 21 and 31 of the thin film portions 20 and 30 include: modified olefin resins such as low-, medium-, high-density Polyethylene (PE), linear low-density polyethylene (LLDPE), linear ultra-low density polyethylene (LULDPE), isotactic polypropylene (PP), propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ionomer olefin copolymer, olefin resins graft-modified with ethylenically unsaturated carboxylic acids or anhydrides thereof, and the like.

Further, as specific materials of the 2 nd layers 22 and 32 of the thin film portions 20 and 30, stretched films can be preferably used, and: polyamide films such as nylon films, and polyester films such as polyethylene terephthalate (PET) films.

The thickness of the 1 st layer 21, 31 of each thin film part 20, 30 is set to about 18 to 200 μm, and the thickness of the 2 nd layer 22, 32 of each thin film part 20, 30 is set to about 10 to 40 μm. The 1 st layers 21, 31 are formed to be about 1.8 to 20 times thicker than the 2 nd layers 22, 32.

The total thickness of the thin film portions 20 and 30 (including the other layers when the thin film portions 20 and 30 have layers other than the 1 st layers 21 and 31 and the 2 nd layers 22 and 32) is about 30 to 300 μm.

Next, a method for three-dimensional molding of a film and a method for producing a molded film article in the present embodiment will be described.

First, the pouch 10 having the crotch portion 40 (the film overlapping portion 50) is manufactured.

Next, the film overlapping portion 50 obtained by overlapping the film portions 20 and 30 in an unfixed state with each other along the thickness direction is subjected to cold compression molding, specifically, as shown in fig. 3, a total of 4 film portions 20 and 30 arranged at the film overlapping portion 50 are sandwiched and compressed by a pair of compression tools (molds) 60 arranged outside the outer film portions 30, and thereafter, the compressed state is released, whereby the projecting portion 23 is formed by projecting a part of the inner film portion 20 toward the 2 nd layer 22 side as shown in fig. 2. This enables the extension portions 23 to be formed at positions where the inner film portions 20 overlap each other.

Further, by the above-described compression molding, as shown in fig. 4, no three-dimensional processing mark remains on the outer film portion 30, or even when a three-dimensional processing mark (not shown) is formed, only a small three-dimensional processing mark, that is, a three-dimensional processing mark having a smaller deformation amount in the thickness direction than the protrusion amount of the protrusion portion 23 in the thickness direction remains.

The three-dimensional processing trace refers to: when a three-dimensional processing mark is formed on the outer film portion 30 at a portion that is deformed in a concave-convex manner in the thickness direction by being compressed by the compression tool 60, the three-dimensional processing mark is formed in a state where the inner film portion 20 and the outer film portion 30 are arranged to overlap as shown in fig. 2: in the vicinity of the position 33 corresponding to the extension portion 23 of the inner film portion 20.

Here, the protrusion phenomenon occurring when the inner thin film portion 20 is cold-compressed in the thickness direction is not clearly understood, but is considered to be caused by the following factors: in the operation when the thickness of the inner film portion 20 is restored after the compressive force is removed, the 1 st layer 21 having a relatively large elongation is also largely restored, and the 2 nd layer 22 having a relatively small elongation is also slightly restored.

In addition, as described above, when cold compression molding is performed in the thickness direction, no three-dimensional processing mark remains on the outer film portion 30 or only a small three-dimensional processing mark remains on the outer film portion 30, and the protrusion phenomenon of the inner film portion 20 occurs due to this, which is considered to be because: when the film overlapping portion 50 is compression molded by the compression tool 60 from the outside of the outer film portion 30, friction between the film portions (between the inner film portion 20 and the outer film portion 30 and between the inner film portions 20) is smaller than friction between the outer film portion 30 and the compression tool 60, and the inner film portion 20 is thereby stretched in the film plane direction and compressed greatly in the thickness direction than the outer film portion 30.

In the present embodiment, 2 pieces of inner film portions 20 are disposed between 2 pieces of outer film portions 30, but 1 piece, 3 pieces or more of inner film portions 20 may be disposed. In this case, the extension portions 23 can be formed on the 2 nd layer 22 side of all the inner thin film portions 20 of 3 or more.

When 2 or more inner thin film portions 20 are disposed between the outer thin film portions 30, at least 2 of the 2 or more inner thin film portions 20 are preferably disposed: the 2 nd layers 22 are opposed to each other.

In order to form the protruding portion 23 satisfactorily, as is apparent from the test results shown in fig. 5 (test results when the film is 1 sheet), it is preferable to design the compression molding ratio of the inner film portion 20 in the thickness direction as: the thickness of the inner film portion 20 is 20% to 65%.

In order to form the protruding portion 23 satisfactorily, as is apparent from the test results shown in fig. 5 (test results when the number of films is 3 to 6 (consisting of 2 outer film portions 30 and the remaining number of inner film portions 20)), it is preferable to design the compression molding ratio of the inner film portions 20 and 2 outer film portions 30 in the thickness direction so that: the total thickness of the inner film portion 20 and the 2 outer film portions 30 is 20% to 35%.

If the compression molding ratio is set too low, the projecting portion 23 cannot be formed in the inner film portion 20, and if the compression molding ratio is set too high, the inner film portion 20 is excessively extended, which may cause damage such as breakage of the inner film portion 20.

The test shown in FIG. 5 was carried out using film portions 20 and 30 obtained by laminating 15 μm (1 st layers 21 and 31), 12 μm PET, and 120 μm LLDPE (2 nd layers 22 and 32) of a nylon film.

While the embodiments of the present invention have been described above in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the claims.

For example, although the above embodiment has been described in which the film molded body is the bag 10, the specific form of the film molded body is not limited to the bag 10, and any form may be used as long as a film is used as a constituent material of a part thereof.

In the above embodiment, the following description is made: the film overlapping portion 50 formed by cold compression molding in the thickness direction is set in the crotch portion 40 of the pouch 10, but the specific position of the film overlapping portion 50 may be any position as long as at least 1 of the inner film portions 20 is disposed between 2 of the outer film portions 30 in an unfixed state.

In the above-described embodiment, the crotch unit 40 is described as being formed at the bottom of the pouch 10, but the specific formation position of the crotch unit 40 may be any position such as the side of the pouch 10.

In the above embodiment, the following description is made: as shown in fig. 7(a), in the crotch unit 40, the inner film portions 20 are connected at their upper ends and folded back in a V-shape, and each outer film portion 30 is heat-bonded at its lower side (bottom side) to the opposing inner film portion 20. However, the crotch unit 40 may be formed by heat-bonding the inner film portion 20, which is folded back 3 times like a W-shape, between the outer film portions 30, or may be folded back 3 times or more. Further, without being limited thereto, the crotch portion 40 composed of the outer film portion 30 and the inner film portion 20 may be formed by folding 1 sheet of film 3 times in an M shape, or the crotch portion 40 composed of the outer film portion 30 and the inner film portion 20 may be formed by folding 1 sheet of film 2 times in a zigzag manner, folding 1 sheet of film 4 times in a zigzag continuous manner, folding 1 sheet of film 5 times with W interposed therebetween, or folding 5 times or more.

Fig. 7(b), 7(c), 8(a), and 8(b) show modifications of the crotch unit 40. Fig. 7(a) to 7(c), 8(a) and 8(b) schematically show the bag 10 before the extension 23 is formed.

In the above embodiment, the following description is made: in the film overlapping portion 50, 2 pieces of the inner film portions 20 are disposed between the outer film portions 30, but the number of the inner film portions 20 may be 1 or more, and for example, as shown in fig. 6, only 1 piece of the inner film portion 20 may be disposed between 2 pieces of the outer film portions 30, and compression molding may be performed.

In the above embodiment, the following description is made: the inner thin film portion 20 is formed by bonding only two layers of the 1 st layer 21 and the 2 nd layer 22, but another layer (a metal layer made of metal such as aluminum, a layer made of another stretched resin film, or the like) may be provided between the 1 st layer 21 and the 2 nd layer 22 or outside the 1 st layer 21 or the 2 nd layer 22.

In the above embodiment, the following description is made: the protruding portion 23 functions as a support portion when the crotch portion 40 is expanded, but the protruding portion 23 may be formed for any purpose, for example, the protruding portion 23 may be formed for the purpose of decoration, braille processing, slip prevention, and the like by using the shapes of characters, patterns, and symbols. Thus, a decorative effect that has not been achieved so far can be obtained in the film molded body, and the range of general design can be expanded.

In the above embodiment, the following description is made: as with the inner thin film portion 20, the outer thin film portion 30 is also formed by a 2-layer structure composed of a 1 st layer 31 and a 2 nd layer 32, but the specific form of the outer thin film portion 30 may be arbitrary, for example, as shown in fig. 6, a 1-layer structure film may be used, and the specific material of the outer thin film portion 30 may be arbitrary.

Description of the reference numerals

Bag (film forming body)

Inner thin film portion

Layer 1

Layer 2

An extension portion

Folding part

A fold back line

An outer membrane portion

Layer 1

Layer 2

A crotch portion

A site of overlap of the film

Compression tool

Thermal bond 70