JP2005001222A - Method for manufacturing injection-molded boot having opening part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an injection-molded boot capable of instantaneously changing over the production of a boot having an opening part provided to the body part thereof to the production of a boot having an opening part different in shape and capable of beautifully finishing the appearance of the boot. <P>SOLUTION: In the method for manufacturing the injection-molded boot wherein an opening part 21 is provided to the body part and/or upper part of a boot main body, a foot mold 4 is covered with a socks-like inner material 6 containing a fiber material or a porous material and at least one sheet piece 2 is held between the foot mold and an outer mold 5 through the inner material while an injection filling gap 7 is formed. A synthetic resin material is injected in the injection filling gap to be joined to the inner material and the sheet piece is fitted to form the boot main body. The sheet piece is detached after the boot is demolded to form the opening part to the boot main body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection-molded boot that is lightweight and has a good design by providing an opening in a shoe body, and more specifically, a shoe in which a sheet piece is loaded at a site where the opening is formed. The present invention relates to a method for manufacturing an injection-molded boot, in which a main body is injection-molded and then demolded, and thereafter a sheet piece is removed to form an opening, thereby minimizing distortion of the opening due to demolding.
[0002]
2. Description of the Related Art Conventionally, in injection-molded boots, a projecting portion that comes into contact with a sock material placed on a side mold (outer mold) and a last mold (foot mold) in order to reduce the weight of the shoe. Since the boot molding material does not enter the projecting portion by providing injection molding, a method of forming a boot window (opening) in which the surface of the sock material is exposed is known. (For example, see Patent Document 1)
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 7-30702
According to the invention described in Patent Document 1, an opening can be easily provided in the body of the shoe body, and the sock material has a property of passing moisture. In addition, it is very convenient because it can reduce the weight and prevent foot stuffiness.
By the way, recently, there is a demand from consumers to wear something different from others if possible. However, if the projecting part is provided on the outer mold, it takes time to change the mold, etc. to change the product type, and in addition to the problem of increased manufacturing costs, the boots are removed from the foot mold. When molding, there is a problem that stress concentrates on the periphery of the opening and distortion generated in the portion remains later.
The present invention provides a method for producing an injection-molded boot which can be immediately switched to the production of a boot having a shape with a different opening when producing a boot having an opening in the trunk, and can be finished with a beautiful appearance. The purpose is to provide.
[0005]
Means for Solving the Problems The method of manufacturing an injection-molded boot of the present invention is a method of manufacturing an injection-molded boot having an opening in the body and / or the heel of the shoe body, comprising a fiber material or After putting the sock-like inner material comprising a porous material on the foot mold, one or more sheet pieces are sandwiched between the foot mold and the outer mold via the inner material, and an injection filling gap is formed, A structure in which a synthetic resin material is injected and filled into the gap, joined to the inner material, and a shoe body is formed by fitting a sheet piece, and after the boot is removed, the sheet piece is removed to form an opening in the shoe body. It is. At that time, it is preferable that the upper part of the inner material is sandwiched between the foot mold and the outer mold and the synthetic resin material is injected from the shoe sole side (bottom side) of the gap.
Moreover, it is preferable to use a sock with a waterproof material attached to at least the opening.
The shoe body is the part that forms the most shape of the shoe by filling the mold with a synthetic resin material, and consists of at least the torso and the upper part, but at the same time the bottom (shoe bottom) It may be integrally molded.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an injection-molded boot having an opening of the present invention will be specifically described.
First, as shown in FIG. 1, a sock-like inner material 3 is covered on a foot mold 4, and one or more sheet pieces 2 are placed between the inner material and the outer mold 5 at a portion where a trunk portion or a heel portion is molded. The mold is closed so that the upper part of the inner material is clamped between the foot mold and the outer mold on the upper part 6 of the upper part of the shoe body, thereby forming a shoe body molding gap 7. In order to clamp the sheet piece between the molds, the sheet piece is placed on the outer mold and then the foot mold and the outer mold are closed, or the sheet piece is easily attached temporarily to the outer mold (for example, weak A sticky double-sided tape attached to a sheet piece) is temporarily attached to the outer mold, and then the foot mold and the outer mold are closed.
[0007]
Then, the synthetic resin material is heated to, for example, about 180 ° C., and fluidity is injected into the gap from the injection port 9 on the bottom side. The synthetic resin material is filled into the gap while discharging air from the position where the foot mold and the outer mold abut each other and the position where the outer mold and the outer mold abut each other to form the shoe body. At this time, the flow of the synthetic resin material is hindered by the presence of the sheet piece, and there is a possibility that an air pool may be generated. Therefore, even if an air pool is generated, the air is pushed out to the inner material side by the pressure of the injection and is discharged from the upper part through the pores or bubbles present in the inner material, so that the synthetic resin material is not unfilled. Such an effect is remarkable when a plurality of sheet pieces are used, particularly when a plurality of sheet pieces are used in the vertical direction.
In addition, when the synthetic resin material is injected and filled, the shoe body is bonded to the inner material by penetrating the pores and bubbles of the inner material over the entire inner surface thereof.
Then, after the synthetic resin material is cooled and solidified, the outer mold is opened from the foot mold, the molded boot is removed from the foot mold, and the sheet piece is removed from the boot to obtain an injection-molded boot having an opening.
As described above, according to the present invention, the synthetic resin material can be more reliably filled into the periphery of the opening, and stress concentration on the periphery of the opening at the time of demolding can be prevented as compared with a conventionally known method. It is possible to prevent the occurrence of distortion at the site, and as a result, it is possible to obtain a boot having a beautiful appearance.
[0008]
As the outer mold, one bottom mold and two side molds may be used in order to form a space for molding boots between the normal foot mold, but the shoe sole portion has two or more colors. For this purpose, a dummy bottom type may be used.
[0009]
The inner material used in the present invention is produced by processing a material including a fiber material or a porous material into a sock like by sewing. As the fiber material, knitted fabrics such as knitted fabrics and tricots are preferably used, but stretchable woven fabrics and nonwoven fabrics processed using elastic fibers may also be used. Examples of the porous material include foamed sheets made of synthetic resin such as flexible polyurethane foam. For example, the inner material may be produced by using a fiber material alone, but a material obtained by laminating a water-resistant film on the fiber material, a material obtained by laminating a fiber material and a polyurethane foam sheet, and a polyurethane foam sheet It can be produced using a material in which a film having water resistance is laminated. That is, as a material for producing the inner material, a material having pores or bubbles inside that can be compressed in the thickness direction is used.
[0010]
The sheet piece may be any material as long as it does not strongly bond to the synthetic resin material forming the shoe body, and a rubber sheet such as styrene butadiene rubber or ethylene propylene rubber, or a synthetic resin such as polyethylene or polypropylene may be used as a main component. it can. Alternatively, paraffin-based, silicon-based, and fluorine-based water repellents may be added and mixed to form sheet pieces, or the obtained sheet pieces may be coated with these water repellents.
Examples of these sheet pieces include those obtained by punching a sheet obtained by casting, calendaring, extrusion, or the like into a desired shape, or those obtained by injection molding, injection molding, or the like.
[0011]
The sheet piece may be a non-foaming type or a foaming type. The hardness of the sheet piece is 30 to 95 degrees for the non-foaming type (spring hardness test A type), and 40 to 98 degrees for the foaming type ( Spring hardness test C type) can be used, but more preferably, the value measured using the same hardness meter regardless of non-foaming / foaming is minus 50% to plus 5% based on the hardness of the boots It is to be.
If the foam type is used, there is an advantage that when the mold is closed, even if the thickness of the sheet piece is somewhat thick, it is crushed and can be stored in the mold without difficulty.
[0012]
Further, the thickness t1 of the sheet piece is usually set to 2 to 3.5 mm in the thickness of the boots in the vicinity of the portion where the opening is provided, so that the distance between the foot mold and the outer mold at the clamping position of the sheet piece is T (Mm), the original thickness of the inner material (JIS L1018) is t2 (mm), and the thickness when strongly compressed (measured by sandwiching a sample cut into a 1 cm square with calipers with a force of about 10 kg) When the non-foamed type is used when t3 (mm) is set as the thickness after compression), T-t3 + 1>t1> T-t2. With such a configuration, when manufacturing boots, the positional relationship between the foot mold and the outer mold due to the presence of the sheet pieces is misaligned (for example, a sheet piece thicker than the distance between the foot mold and the outer mold is sandwiched therebetween) As a result, the sheet piece portion and the portion made of the synthetic resin material can be finished almost smoothly. Furthermore, if T−t3 + 1> t1 ≧ T−t3, the synthetic resin material can be prevented from appearing as burrs on the surface side of the sheet piece. Also, if the foam type is used, especially if care is taken to satisfy t1 ≧ T−t3, it will be crushed even if it is a little thick, so the above-mentioned problems are unlikely to occur, and the inner material is waterproof. There is little risk of impairing the water resistance and moisture permeability of the waterproofing material when using the one attached with.
[0013]
Examples of the synthetic resin material forming the shoe body include those conventionally used, such as those mainly composed of synthetic resins such as vinyl chloride resin and styrene butadiene copolymer elastomer.
[0014]
In the boots obtained in the present invention, the inner material is exposed at the opening. The exposed inner material is preferably waterproofed by applying or spraying a paraffin-based, silicon-based or fluorine-based water repellent.
[0015]
In addition, if the waterproofness of the opening is insufficient with the above method, or if you want to decorate the opening, use a waterproof or decorative waterproof material at least at the opening as an inner material. It is preferable to use an attached one. The waterproof material having the waterproof, 1000mmH ₂ 0 or more, preferably may be used those having 2000mmH ₂ 0 or more water pressure resistance. Examples of the material having such a water pressure resistance include leathers such as vinyl chloride leather, acrylic leather, polyurethane synthetic leather, artificial leather, and natural leather. In addition, if a material having a moisture permeability of 2000 gr / m ² · 24 Hr or more is used as a waterproof material, it can be a countermeasure against stuffiness. As a material having both water resistance and moisture permeability, for example, an organic solvent solution mainly composed of a polyurethane resin composed of a polycarbonate diol, an organic diisocyanate, and a chain extender is coated on a base cloth for wet processing. Porous synthetic leather produced by As a decorative waterproofing material, a knitted fabric, a woven fabric, a non-woven fabric or the like imparted with a pattern or color can be suitably used.
[0016]
【Example】
Examples of the present invention will be described below.
(Example 1)
First, as shown in FIG. 1, a foot mold 4 and an outer mold 5 (two side molds 51 and one bottom mold 52) were prepared. The distance T formed between the foot mold and the outer mold was 2.2 mm at the position where the sheet piece is sandwiched.
A sheet piece is prepared by adding 80 parts by weight of a plasticizer and 2 parts by weight of a stabilizer to 100 parts by weight of a vinyl chloride resin. A 2.1 mm non-foamed sheet is produced by casting and punched into a heart shape. A synthetic resin sheet piece 2 was prepared and sprayed with a commercially available fluorine-based water repellent. The sheet piece had a hardness of 60 degrees (spring hardness test A type).
As a synthetic resin material for forming a shoe body, a compound was prepared by adding 80 parts by weight of a plasticizer, 2 parts by weight of a stabilizer and 3 parts by weight of a blue pigment to 100 parts by weight of a vinyl chloride resin.
As an inner material, nylon tricot was laminated on both sides of a flexible polyurethane foam to produce a material having a thickness of 0.8 mm, and this was cut and sewed to produce a sock-like inner material 3. In addition, the thickness at the time of compression of this inner material was 0.1 mm.
Then, the inner material 3 produced as described above is put on the foot mold, and the foot mold 4 and the outer mold 5 are placed through the inner material 3 so that each of the three sheet pieces 2 is located outside and inside the shoe. The gap 7 was formed by sandwiching the upper part of the inner material between the foot mold and the outer mold at a position 6 where the outer mold and the outer mold abut each other.
Thereafter, the synthetic resin material is heated to 180 ° C. with an injection molding machine, and injected into the gap 7 through the injection port 9 on the shoe sole side to form the shoe body. After the shoe body is cooled and solidified, it is demolded, and the sheet is removed. The piece was removed to form an opening, and a commercially available water repellent was sprayed on the inner material located in the opening to obtain an injection-molded boot 1 having an opening in the trunk. The hardness of the shoe body was 70 degrees (A type).
The obtained injection-molded boots 1 had an appearance as shown in FIG. 2 and had no unfilled portions and no distortion at the periphery of the opening. Furthermore, since the opening of the present embodiment is provided on the left and right sides of the torso, it can be easily folded at the opening, and if the boots are folded, the storage space can be reduced.
[0017]
(Example 2)
The same procedure as in Example 1 was performed except that a waterproof material was sewn on the inner material and the sheet piece was made a foam type.
As a sheet piece, 80 parts by weight of a plasticizer, 1 part by weight of a foaming agent (azodicarbonamide) and 2 parts by weight of a stabilizer are added to 100 parts by weight of a vinyl chloride resin. A 2.1 mm thick foam sheet was produced, and a sheet piece was produced in the same manner as in Example 1 using this foam sheet. The hardness of the sheet piece was 70 degrees (C type) and 40 degrees (A type).
As a waterproofing material, a dimethylformamide solution of polyurethane colored in yellow was applied to a water-repellent treated base fabric with a clearance of 100 μm, and wet-treated to obtain a porous synthetic leather having a thickness of 0.5 mm. Water pressure of the synthetic leather 2500mmH ₂ 0, moisture permeability was 3500gr ^/ m 2 · 24Hr. The synthetic leather is cut to produce a waterproof material 10, and as shown in FIG. 4, the waterproof material is sewn in a portion corresponding to the opening of the same inner material as used in Example 1, and the inner material is sewn. It was set to 3. The original thickness of the inner material in the opening was 1.3 mm, and the thickness when compressed was 0.4 mm.
And the injection-molded boots 1 which have an opening part in the trunk | drum by the method similar to Example 1 were obtained. The shoe body had a hardness of 70 degrees (A type).
The obtained injection-molded boots 1 had an appearance as shown in FIG. 2 and had no unfilled portions and no distortion at the periphery of the opening. Further, the opening could be made water-resistant and moisture-permeable, and the color of the opening was different from that of the shoe body, and the decoration was rich. Furthermore, since the opening of the present embodiment is provided on the left and right sides of the torso, it can be easily folded at the opening, and if the boots are folded, the storage space can be reduced.
[0018]
【The invention's effect】
According to the method of manufacturing an injection-molded boot of the present invention, when manufacturing a boot having an opening in the trunk, the manufacturing can be immediately switched to a boot having a different shape of the opening, and a sheet piece is attached to the shoe main body. Since the mold is removed in a state in which is inserted, it is possible to prevent concentration of stress on the peripheral edge of the opening at that time, and as a result, it is possible to prevent distortion from occurring in the portion.
[Brief description of the drawings]
1 is an explanatory diagram of a schematic positional relationship between a foot mold and an outer mold and a sheet piece in an injection process, and is an explanatory diagram of a portion corresponding to an AA cross section of an injection molded shoe 1 of FIG. 2;
FIG. 2 is a side view of an injection-molded boot of the embodiment.
FIG. 3 is a perspective view of a sheet piece.
[Figure 4] Side view of inner material sewn with waterproof material [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Injection molding boots 2 Sheet piece 21 Opening part 3 Inner material 4 Foot mold 5 Outer mold 6 Position where an outer mold and an outer mold collide 7 Gap 8 Shoe body 9 Injection port 10 Waterproof material

Claims (3)

A method for manufacturing an injection-molded boot having an opening in a body and / or a hood of a shoe body,
After the sock-like inner material comprising fiber material or porous material is put on the foot mold, one or more sheet pieces are sandwiched between the foot mold and the outer mold via the inner material, and an injection filling gap is formed. An injection molding characterized by forming a shoe main body formed by injection filling and filling the gap with a synthetic resin material and joining the inner material, and removing a sheet piece after demolding the boots to form an opening in the shoe main body A manufacturing method for boots. 2. The method for manufacturing an injection-molded boot according to claim 1, wherein the upper part of the inner material is sandwiched between the foot mold and the outer mold, and the synthetic resin material is injected from the shoe sole side. 2. The method for manufacturing an injection-molded boot according to claim 1, wherein the inner material is a waterproof material affixed to at least the opening.

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