KR20150135816A - Multi-shape toe cap using ultralight complex material and method of manufacturing same - Google Patents

Abstract

The present invention relates to a multi-shape toe cap using an ultralight complex material and, more specifically, to a multi-shape toe cap using an ultrailight complex material, which is manufactured in a multiformat using the ultralight complex material including a non-woven fabric, a film, a glass fiber reinforced plastic, and PET as an existing iron and plastic replace a material with a toe cap which protects a toe while being located in a front end portion of a safety shoe, and to a method for manufacturing the same. According to the present invention, the multi-shape toe cap using an ultralight complex material includes the non-woven fabric, the film, the glass fiber reinforced plastic, a polyethylene terephthalate (PET) non-woven fabric. In addition, according to the present invention, the manufacturing method comprises: a first step of forming a laminated structure; a second step of foaming the laminated structure; a third step of performing thermoforming on the foamed laminated structure using a mold of a multi-shape structure; and a fourth step of cold-forming the thermoformed laminated structure.

Description

Technical Field [0001] The present invention relates to a multi-shaped toe cap using an ultra-lightweight composite material and a method of manufacturing the multi-

The present invention relates to a multi-shaped toe cap using an ultra-light composite material, and more particularly, to a toe cap which is located at the front end of a safety boot and protects the toe, The present invention relates to a multi-shaped toe cap using an ultra-lightweight composite material produced by using a lightweight composite material including plastic, PET, and the like.

Generally, the toe cap is made of metal material to protect the toe area, and thus it is used to protect the foot from the industrial site or the construction site to prevent a catastrophic disaster such as toe nerve disorder or cutting due to excessive impact.

However, such a toe cap is not smoothly ventilated and causes skin diseases or deformations of the foot of a worker, and the weight is so heavy that the movement of the worker is inconvenient and the efficiency of the work is lowered.

In order to solve such a problem, Korean Patent No. 10-0976265 has registered a 'safety plastic toccap'. The plastic toe cap for safety purpose is a tocap which improves impact resistance and light weight by forming a composition optimized for a toe cap among plastic materials, and has a tocap which is made by mixing polycarbonate and polybutylene terephthalate .

However, such a conventional technique has a problem in that economic efficiency due to expensive plastic material is inferior, and ventilation is difficult, which may cause skin diseases of an operator.

In addition, since the process of mixing, drying, injection, and extraction is included in the process of manufacturing the toe cap, excessive time is invested in each step, thereby deteriorating the efficiency of the operation.

Korean Registered Patent No. 10-0976265 Plastic toe cap for safety

It is an object of the present invention to provide a toe cap having sufficient impact strength, compressive strength, and restoring force as a tow cap while reducing the weight of the safety cap.

It is also an object of the present invention to provide a multi-shaped toe cap using an ultra lightweight composite material that can be ventilated smoothly due to the finish of the PET nonwoven fabric to prevent skin diseases of the operator.

It is another object of the present invention to provide a method of manufacturing a multifunctional toe cap using an ultra lightweight composite material which is improved in energy saving, durability and impact resistance through high temperature compression molding.

It is another object of the present invention to provide a method of manufacturing a multi-shaped toe cap using an ultra-light composite material capable of manufacturing various shapes of toe caps with various cavity configurations of a mold during press molding of one laminated structure.

The multifunctional toe cap using the lightweight composite material according to the present invention is characterized by comprising a nonwoven fabric, a film, a glass fiber reinforced plastic, and a polyethylene terephthalate (PET) nonwoven fabric.

Also, a method of manufacturing a multifunctional toe cap using an ultra lightweight composite material according to the present invention includes: a first step of forming a laminated structure; A second step of foaming the laminated structure; A third step of thermoforming the foamed laminated structure using a mold having a polytype structure; A fourth step of cold-molding the thermoformed laminated structure; And a control unit.

According to the solution of the above-mentioned problems, the multifunctional toe cap using the light-weight composite material of the present invention is excellent in lightweightness of the stabilization and improved functionality of the ventilation property, including nonwoven fabric, film, glass fiber reinforced plastic and PET non- It has an impact resistance, a compressive strength, a good restoring force, a good thermoplasticity and excellent moldability, and can be manufactured into a polygonal shape.

FIG. 1 is a view showing a laminated structure of a composite material used in the production of a multi-shaped tow cap using the light-weight composite material of the present invention.
2 is a view showing an example of a multi-shaped toe cap shape using the lightweight composite material of the present invention.
3 is a view showing an example of a multi-shaped toe cap mold using the lightweight composite material of the present invention.
4 is a view showing an example of a multi-shaped toe cap mold using the lightweight composite material of the present invention.

The composite material of the multifunctional toe cap using the lightweight composite material according to the present invention includes a nonwoven fabric, a film, a glass fiber reinforced plastic, and a polyethylene terephthalate (PET) nonwoven fabric.

FIG. 1 is a view showing a laminated structure of a composite material used in the production of a multi-shaped tow cap using the light-weight composite material of the present invention.

The laminated structure of the multifunctional toe cap composite material using the lightweight composite material according to the present invention comprises a nonwoven fabric layer made of an alpha olefin resin; A film layer for imparting an adhesive function; A glass fiber reinforced plastic layer comprising polyethylene and glass fibers; And a polyethylene terephthalate (PET) layer for protecting the appearance.

The nonwoven fabric preferably has a melt index (MFI) of 2.0 to 9.0 g / 10 min, a density of 0.88 to 0.92 g / cm < 3 >, and a thickness of 100 to 150 mu m as an alpha olefin resin.

When the melt index (MFI) of the alpha-olefin resin used as the nonwoven fabric is less than 2.0 g / 10 min, the surface of the product may be defective due to the decrease in the fluidity of the resin during high- The physical properties may be deteriorated.

When the density of the alpha-olefin resin used as the nonwoven fabric is less than 0.88 g / cm < 3 >, the light weight of the nonwoven fabric is increased but the bi-directional elongation and tensile strength for maintaining the shape of the product may be reduced. There is a problem that the spacing of the nonwoven fabric is dense and the surface of the nonwoven fabric may be defective when taken out after the press work due to the tension of the fibers.

If the thickness of the nonwoven fabric used as the nonwoven fabric is less than 100 mu m, the shape of the nonwoven fabric may be deformed. If the thickness of the nonwoven fabric is more than 150 mu m, the moldability of the outer appearance of the product may deteriorate.

The film is a layer for imparting an adhesive function, and the film is placed between the nonwoven fabric and the glass fiber reinforced plastic to give an adhesive force.

The film is melted at a high temperature to form a double layer with the nonwoven fabric. At the same time, the glass fiber is impregnated into the film, and is fixed in the cooling process after the molding to maintain its shape.

Preferably, the film uses a breathable polypropylene film for the breathable function of the tow cap.

The glass fiber reinforced plastic serves as the main stiffness of the multifunctional toe cap substrate using the lightweight composite material.

The glass fiber reinforced plastic includes polypropylene, fibrous glass and additives. The glass fiber reinforced plastic preferably comprises 25 to 75% by weight of polypropylene, 25 to 75% by weight of fibrous glass, and 0 to 5% by weight of an additive.

When the content of the polypropylene constituting the glass fiber reinforced plastic is less than 25% by weight, the foaming magnification is low and the formability and shape of the material become difficult to implement. When the content of the polypropylene is more than 75% by weight, There is a problem that the rigidity of the stator is deteriorated.

When the content of the fiberglass constituting the glass fiber reinforced plastic is less than 25% by weight, the stiffness of the material decreases. When the content of the fiberglass exceeds 55% by weight, the maximum rigidity is obtained. Difficulties arise.

The glass fiber reinforced plastic may further include an antioxidant, a pigment, a plasticizer and the like as an additive.

The permissible concentration of polypropylene and fiberglass composing the glass fiber reinforced plastic is preferably 10 mg / mł, the allowable exposure limit is 5 mg / mł, the allowable concentration of the additive is 3.5 mg / mł, the permissible exposure limit is 3.5 mg / m < 3 >.

The polyethylene terephthalate (PET) nonwoven fabric is adhered to the back surface of the glass fiber reinforced plastic, and performs deflection of the fabric during the molding and a function of suppressing the glass fiber, and also imparts scratch resistance to the outside.

The PET nonwoven fabric preferably has a thickness of 4 to 10 T (mm) and a tensile strength of 150 to 350 kg / in.

If the thickness of the PET nonwoven fabric is less than 4T, the effect of preventing sagging of the fabric may be deteriorated. If the thickness is more than 10T, the weight of the tow cap may be reduced.

The PET nonwoven fabric preferably contains a chemical foaming agent therein and is preferably capable of foaming at 100 to 150 ° C within 2 minutes.

Hereinafter, a method of manufacturing a multi-shaped tow cap using the lightweight composite material of the present invention will be described in detail with reference to the drawings.

First, a laminated structure is formed in the first step. Specifically, a laminated structure is formed using an ultralight composite material.

The laminated structure includes a nonwoven fabric layer made of an alpha-olefin resin; A film layer made of a breathable reinforced polypropylene film; A core layer comprising polyethylene and glass fibers; And a polyethylene terephthalate (PET) layer for protecting the appearance.

Next, in the second step, the laminated structure is laminated. Specifically, four sheets of the nonwoven fabric layer, the film layer, the core layer and the PET layer, which are the laminated structures, are formed by thermoforming at 150 to 200 ° C.

If the heat molding is carried out at a temperature of less than 150 ° C, the intercalation of the sheets may not occur uniformly, and if the temperature exceeds 200 ° C, there is a problem of deterioration of the sheet or inefficiency due to the necessity of high heat.

Next, in the third step, the laminated laminated structure is thermoformed using a mold having a polygonal structure. Specifically, the composite material of the laminated structure is transferred to a mold having a polygonal structure, and is then subjected to high-temperature compression using a vacuum hot press.

The vacuum hot press is preferably a vacuum hot press of 150 ton or more in the order of 350 to 420 ° C in series, and preferably a pressure of 2 to 3 bar at 190 to 205 ° C under high temperature compression.

If the temperature is lower than 190 ° C, the moldability of the product is lowered and the defective rate is increased. When the temperature is higher than 205 ° C, the cooling time becomes longer and the efficiency of the operation is lowered.

If the pressure is less than 2 bar, the shape of the product may not be realized and the adhesion between the laminated layers may be lowered. If the pressure is higher than 2 bar, the nonwoven fabric part breakage due to excessive compression, Defects such as overlapping may occur.

As shown in FIG. 2, the mold of the polygonal structure is preferably designed so that the toe cap of the present invention can have various shapes. For example, five or more kinds of products are produced by automatically desorbing through a vertical compression vacuum press molding process using a mold having an upper height of 50 to 120 cm, which is formed by using 5-axis air.

3 to 4 are views showing a 3D shape structure of an example of the toe cap mold of the present invention.

Next, in the fourth step, the thermoformed laminated structure is cold-formed. Specifically, the thermoformed laminated structure is cold-formed to complete the manufacture of the toe cap.

In the following, examples and comparative examples are shown in order to examine the quality characteristics such as weight reduction and durability of the multi-type toe cap using the lightweight composite material of the present invention.

[Example 1]

Example 1 is a method for producing a multifunctional tow cap using the lightweight composite material of the present invention, which comprises an alpha olefin resin nonwoven fabric layer; A polypropylene film layer; A core layer composed of 50% by weight of polyethylene and 50% by weight of glass fibers; A polyethylene terephthalate (PET) layer; Which is a multi-shaped toe cap using an ultra-light composite material.

[Comparative Example 1]

Comparative Example 1 is a generally used steel cap.

division Example 1 Comparative Example 1 importance 0.3 g / m³  7.93 g / m³ Impact strength 135 J / m 142 J / m

As shown in Table 1, the specific gravity of the multi-shaped tow cap using the light-weight composite material excellent in impact strength of the present invention is as low as 0.3 g / m < 3 >, which is 10% or less of 7.93 g / Has a sufficient impact resistance as a toe cap with a physical property of 90 to 155 J / m or less.

That is, according to the manufacturing method described above, it is possible to manufacture a multifunctional toe cap using a lightweight composite material having a significantly lower specific gravity than that of a steel material and having an excellent impact strength, and to manufacture a toe cap having a lightweight, It is possible.

Claims (9)

Wherein the nonwoven fabric comprises a nonwoven fabric, a film, a glass fiber reinforced plastic, and a polyethylene terephthalate (PET) nonwoven fabric. The method according to claim 1,
Wherein the nonwoven fabric is an alpha olefin resin and has a melt index (MFI) of 2.0 to 9.0 g / 10 min, a density of 0.88 to 0.92 g / cm < A multi-shaped tow cap The method according to claim 1,
Characterized in that the glass fiber reinforced plastic comprises polypropylene, fibrous glass and an additive. The multifunctional tow cap The method of claim 3,
Wherein the glass fiber reinforced plastic comprises 25 to 75% by weight of polypropylene, 25 to 75% by weight of fibrous glass, and 0 to 5% by weight of an additive. cap The method of claim 3,
Wherein the additive comprises at least one of an antioxidant, a pigment, and a plasticizer. The method according to claim 1,
The polyethylene terephthalate (PET) nonwoven fabric has a thickness of 4 to 10 T and a tensile strength of 150 to 350 kg / in,
Characterized in that foaming is possible within two minutes at 100 to 150 DEG C including a chemical foaming agent, In a multi-shaped toe cap using an ultra light composite material,
And an impact strength of 90 to 155 J / m. A first step of forming a laminated structure;
A second step of fabricating the laminated structure;
A third step of thermoforming the laminated structure by using a metal mold having a polygonal structure;
A fourth step of cold-molding the thermoformed laminated structure; A method of manufacturing a multi-shaped toe cap using an ultra-lightweight composite material 9. The method of claim 8,
In the laminated structure,
A nonwoven fabric layer made of an alpha olefin resin;
A film layer made of a breathable reinforced polypropylene film;
A core layer comprising polyethylene and glass fibers;
A polyethylene terephthalate (PET) layer protecting the appearance;
A method of manufacturing a multi-shaped toe cap using an ultra-lightweight composite material

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