JPH06245804A - Tip core of safety shoe - Google Patents

Abstract

PURPOSE:To obtain a tip core of a safety shoe with light weight and large pressure strength by forming a base material having a metallic gauze layer with specific mesh or metallic gauze layers on both sides of a composite material at the center of a composite material consisting of a reinforced resin and thermoplastic resin. CONSTITUTION:A base material has a metallic gauze 4 of 7-200 mesh in a short fiber layer 2 in the central part of a composite material consisting of reinforcing fiber, which consists of long fiber 5, short fiber 6, and thermoplastic resin 7, or metallic gauze 4 in both sides of the composite material with a long fiber layer in the central part and a short fiber layer in both sides with skin layers 3 on both surfaces. When the metallic gauze 4 is put in between plate shaped composite materials 8, on which the short fiber layer 2 facing to the metallic gauze 4 and the long fiber layer on the opposite side are formed, and heated and pressed, the short fiber layer 2 is brought in around the metallic gauze 4 to make a plate shaped base material 9 that the metallic gauze 4 is buried in the short fiber layer 2. To make a tip core of a safety shoe with the plate shaped base material, the plate shaped base material 9 cut into the shape of a tip core of a safety shoe is put on a female die and heated and pressed by a male die to make the tip core of the safety shoe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shoe toe core which is applied to shoes such as shoes and boots to structurally reinforce the shoe tip and enhance the safety of the shoe.

[0002]

2. Description of the Related Art Conventionally, in the toecap of a safety shoe, the strength of the upper part of the shoe has been regarded as very important for protection against the fall of heavy objects, and only steel products have been put into practical use. Absent.

However, since the steel product is heavy, the workability of the wearer becomes a problem, and recently, in order to reduce the weight, it is disclosed in, for example, Japanese Utility Model Laid-Open No. 64-32609. A toecap with multiple plastic layers on both sides of a steel core was devised.

However, in a toe core in which a steel core material is overlaid with a plastic layer, boundary separation easily occurs between the steel core material and the plastic layer, and as a product, the intended purpose may not be achieved. Further, since the steel is made of steel, the manufacturing of the toecap is also troublesome. Moreover, since the material is steel, it is heavy.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention provides a safety shoe toecap standard (JIS T 8101 leather safety shoes S).
The present invention aims to provide a new lightweight safety shoe toecap that conforms to the type).

[0006]

The structure of the present invention for solving the above problems is a safety shoe toecap as set forth in the appended claims. In summary, the safety of molding a base material having a wire mesh layer of 7 to 200 mesh at the center of a composite material composed of a reinforced resin and a thermoplastic resin or having the wire mesh layer on both sides of the composite material. It is a toecap.

Further, the wire diameter of the wire mesh is 40 to 620 μm.
The diameter of the reinforcing fiber mixed with the resin is 9
A safety shoe toecap having a content of ˜13 μm in the base material limited to 30 to 65%.

Suitable examples of the thermoplastic resin as the base material include nylon 6, polycarbonate (PC),
There are polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), PBT / PC alloy and the like.

The reinforcing fibers are glass fibers. The glass fibers include short fibers and long fibers, and the long fibers have a random mat shape, a woven shape, and a unidirectional mat shape. Among them, short fibers have low strength, and long fibers have sufficient strength, but woven fabrics and unidirectional mats have poor fluidity and thus have a problem in moldability. There is a drawback that it does not become a product. In the present invention, a thermoplastic resin composite material in which glass fibers are mixed so that short fibers are arranged near the wire mesh and long fibers are arranged in other areas is used. By doing this, the fibers can surely wrap around the wire mesh.

First, it is necessary that the content of the glass fiber in the composite material is 30 to 60% and the wire diameter of the glass fiber is 9 to 13 μm. If the content of the glass fibers is less than 30%, the glass fibers will be reduced, and the strength will naturally not be sufficient. Further, when the content of the glass fiber exceeds 60%, the glass becomes brittle. In other words, it becomes hard but loses its resilience and elasticity, and when it is pressed, it concentrates in one place and breaks.

When the wire diameter of the glass fiber is 9 to 13 μm, the strength of the composite material is high. When the wire diameter of the glass fiber is smaller than 9 μm, the surface area becomes large even if the same amount of the glass fiber is contained, so that the thermoplastic resin and the wetting of the glass fiber to the resin are not sufficient and the strength of the base material is not increased.
On the contrary, when the wire diameter of the glass fiber exceeds 13 μm, the strength of the composite material is reduced and the composite material becomes brittle.

Materials of the wire mesh include steel, stainless steel, nickel and the like. In order to enhance the adhesion between the composite resin and the wire net, the wire net may be subjected to a physical or chemical surface treatment. As the physical treatment, there are examples in which the surface is roughened by shot blasting, liquid honing, or the like.

As the chemical treatment, for steel, there are bonderite treatment, chromic acid treatment, silane treatment, galvanization and the like. Chromic acid treatment and oxide film treatment are available for stainless steel mesh.

The present invention will be described in detail with reference to the drawings. FIG. 1 shows a base material in which a wire mesh 4 is contained in a short fiber layer 2 at the center of a composite material composed of a reinforcing resin composed of long fibers 5 and short fibers 6 and a thermoplastic resin 7.

FIG. 2 is a schematic diagram showing a cross section of a base material having a wire mesh 5 on both surface portions of a composite material having a long fiber layer 1 in the center and short fiber layers 2 on both sides and a skin layer 3 on the surface. It is a figure. In both the one shown in FIG. 1 and the one shown in FIG. 2, a short fiber layer 2 is formed around the wire mesh.

FIG. 3 illustrates the manufacturing process of the substrate shown in FIG. On the surface facing the wire net 4, the short fiber layer 2,
As shown in FIG. 1, when the wire mesh 4 is sandwiched between the plate-like composite materials 8 on which the long fiber layers 1 are formed on the opposite surface, and the both surfaces are heated and pressed, the short fiber layers 2 wrap around the wire mesh 4 In addition, a plate-shaped base material in which the wire net 4 is embedded in the short fiber layer 2 is formed.

To manufacture a safety shoe toecap using this plate-shaped base material 9, as shown in FIG. 4, a plate-shaped base material 9 cut into a shape of a safety shoe toecap is molded into a female mold 10. Then, the male mold 11 is lowered from above and heated and pressed to produce a safety shoe toecap as shown in FIG.

The strength of the safety shoe toe box is greatly influenced by the characteristics of the wire mesh. For example, if the size of the wire mesh is less than 7 mesh, the total surface area of the wire mesh will be small no matter how thick the wire diameter of the wire mesh is, and a product having a certain strength cannot be obtained. In addition, even with 7 mesh, if the wire diameter exceeds 620 μm, the adhesiveness with the resin deteriorates, causing cohesive failure of the product.

When the mesh size is 200 mesh, the wire diameter is 40
If it is less than μm, the desired strength cannot be obtained. Fig. 6 shows the target compression strength of 1,100 kg (JI) when a product is manufactured by changing the size of the wire mesh and the diameter of the metal wire.
The relationship between the eye size and the wire diameter that have passed S T 8101 leather safety shoes S type) is shown as a shaded area.

However, the reinforced resin composite material used was nylon 6 resin containing 45% of glass fiber, and the material of the wire mesh was a steel wire subjected to liquid honing treatment followed by chromic acid treatment.

FIG. 7 is a graph showing the relationship between the compression strength and the size of the mesh, which is concretely shown by the product when the wire mesh in the shaded area is used. From this result, if the mesh size is less than 7 mesh, the total surface area of the wire mesh decreases, and the strength of the product varies. Even with 7 mesh, the wire diameter is 62
If it exceeds 0 μm, the adhesiveness with the resin is deteriorated and cohesive failure occurs.

If it exceeds 200 mesh, the reinforcing fibers do not wrap around and delamination occurs. Even with 200 mesh, if the wire diameter is less than 40 μm, sufficient strength cannot be obtained.

FIG. 6 is a graph showing the relationship between the size of the wire mesh and the wire diameter of the metal wire.
This is the case where a strength of 100 Kg is exhibited. However, the composite material was nylon 6 containing 45% of glass fiber.

[0024]

As described above, since the safety shoe toecap of the present invention is lightweight and has a compressive strength of 1,100 Kg, it is easy to operate and safe. It is possible to provide highly reliable shoes.

[Brief description of drawings]

FIG. 1 is a schematic view of a cross section of an example of a base material used in the present invention,

[Fig. 2] Same as above

3 is an explanatory view of an example of a product of the base material of FIG.

FIG. 4 is an explanatory view of a process for producing a safety shoe toecap using the base material of the present invention,

FIG. 5 is an explanatory view of a toecap of a safety shoe of the present invention,

FIG. 6 is a graph showing the relationship between the size of the wire mesh and the compression strength of the toecap of a safety shoe using the mesh.

FIG. 7 is a graph showing the relationship between the size of the wire mesh for obtaining a predetermined strength and the diameter of the metal wire forming the wire mesh.

[Explanation of symbols]

 1 Long Fiber Layer 2 Short Fiber Layer 3 Skin Layer 4 Wire Mesh 5 Long Fiber 6 Short Fiber 7 Thermoplastic Resin 8 Composite Material 9 Plate-shaped Base Material 10 Female Type 11 Male Type

Claims (4)

[Claims] 1. A safety shoe toecap formed by molding a base material characterized in that a composite material composed of reinforcing fibers and a thermoplastic resin has a wire mesh layer of 7 to 200 mesh at the center thereof. 2. A safety shoe toecap formed by molding a base material having a wire mesh layer of 7 to 200 mesh on both surfaces of a composite material composed of reinforcing fibers and a thermoplastic resin. 3. The safety shoe toebox according to claim 1, wherein the wire mesh has a wire diameter of 40 μm to 620 μm. 4. The safety shoe toebox according to claim 1, wherein the reinforcing fiber content is 30 to 65% and the wire diameter is 9 to 13 μm.