KR100653123B1 - Foamless sheet structure and forming method thereof - Google Patents

Abstract

A foamless sheet structure and a molding method thereof are provided to improve the reducing effect of material and weight and decrease the contraction and the torsion by form-molding the lower limb to the skin. A foamless sheet structure comprises an upper lamb layer(31); and a foam layer(32) formed on the lower part of the upper lamb layer, foamed after lamination the with the upper lamb layer, and made of the same material as the upper lamb layer. A cloth layer(34) is contained at the lower part of the foam layer. The upper lamb and foam layers is formed with a TPE(Thermo Plastic Elastomer) with TPO or TPU. The thickness of the upper lamb layer is 0.3~0.9mm, the thickness of the foam layer is 0.5~3.0mm, and the thickness of the cloth layer is 1.0~1.5mm.

Description

FOAMLESS SHEET STRUCTURE AND FORMING METHOD THEREOF

1 is a view illustrating a door trim of a car;

Figure 2 is a cross-sectional view for explaining the skin forming structure of a conventional car door trim

3 is a cross-sectional view for explaining a skin forming structure of a door trim for an automobile according to the present invention;

Figure 4 is a flow chart of the foam (FOAMLESS) foam molding of the door trim for automobiles according to the present invention Figure 5 is a flow chart of the foam molding in the skin molding process of the door trim for automobiles according to the present invention

Explanation of symbols on the main parts of the drawings

10 door trim

12 upper part

13 lower

20 door trim

21 skins

22 Skin Layer

23 Adhesion boundary layer with foam

24 FOAM

25 Adhesive Side

26 Heartwood

30 door trim

31 Skin Layer

32 not foam layer

33 adhesive layer

34 welfare layer

35 heartwood

The present invention relates to a skin material (skin) structure of a car interior trim and a molding method thereof, and in particular, by foaming a lower limb on a skin using an environmentally friendly TPO material, effectively reducing the manufacturing cost and product weight while exerting a sheet effect. The present invention relates to a skin structure of a built-in trim and a molding method thereof.

In general, the interior of the car has been made of materials that are comfortable, comfortable and harmless to the human body.

On the side of the car, there are door trims that open and close the doors and pillar trims that connect the floor to the ceiling of the car. These parts are designed to have a beautiful appearance and protect passengers from accidents. The interior is prepared to do so.

1 is a view illustrating a door trim of a vehicle, and the door trim 10 includes an upper part 12 and a lower part 13. Recently, the door trim (10) has been in the spotlight is a method of injection molding by inserting a skin material with a cushioning material to a low-pressure injection molding machine, which has a cushion itself and has the property of absorbing the required impact. The appearance is beautiful and the form which provides the surface state is widely used.

FIG. 2 is a partial cross-sectional view of a door trim structure of a conventional vehicle, and includes a skin 21 forming a beautiful appearance of a door trim, and a core material 26 serving as a shape retainer, and a skin 21 having a cushion is thin. Plywood made of polyurethane or polypropylene foam sheet 24 having a cushion to the PVC layer 22 and a certain degree of cushioning. The PVC foam sheet is formed into a structure that is inserted into a mold under low pressure to form a core and is injection molded. In order to manufacture the door trim as described above follows the following method.

First, the skin is set between the molds in the low pressure injection molding machine consisting of a press part and an injection part, and the injection resin of a fixed quantity is supplied to the lower mold. As a processing method, this low pressure injection method requires an injection resin injected through a gate of a lower mold after fixing the skin material with a set pin to the upper mold developed from the lower mold, and then inserting the injection resin for the substrate into the mold under low pressure. This method of forming interior materials such as door trims and pillar trims is commonly referred to as low pressure injection molding in the process of producing interior materials as a process for simultaneously bonding the surface of the skin material being molded into the substrate of the substrate. .

Conventionally, the material of the skin material is generally PVC (polyvinyl chloride resin) is generally widely used, but the PVC generates environmental pollutants such as dioxins during odor and incineration, and in advanced countries, regulations on its use are gradually strengthened. There is a situation.

Accordingly, in recent years, environmentally friendly materials such as TPO (olefin-based thermoplastic elastomer) or TPU (polyurethane-based thermoplastic elastomer) have been developed to replace the PVC, and are also attracting attention as skin materials for door trims and pillar trims.

However, the above-mentioned TPO or TPU itself has elasticity, but there is no cushion required as an interior material, so that a separate polyurethane or polypropylene foam is plywood, and thus the manufacturing process is increased, resulting in high cost and weight. In addition, polyurethane or polypropylene foam (FOAM) as a cushioning material has a high elongation to be restored after molding, which has the disadvantage of causing shrinkage and warpage deformation in the product.

Accordingly, it is an object of the present invention to provide an outer skin material for automobile interior material and a molding method thereof which can effectively reduce the material and weight by foaming the lower limbs on the skin by peeling a separate cushioning material from plywood and molding the skin material. .

Another object of the present invention is to provide an outer skin material of a car interior material and a method for forming the same, which have no odor and shrinkage and warping after the upper mold by foaming the skin itself with environmentally friendly TPO.

The foam type TPO sheet is intended to have elasticity and cushion at the same time in one manufacturing process.

In the method for skin forming a door trim for an automobile according to the present invention, the sheet is formed by using a calendering machine of a calender line, or after molding the sheet, plywood is laminated.

Due to the characteristics of the sheet, it is preferable to provide a backing cloth on the back of the sheet so that it can be increased as necessary for each part of the interior material when the insert is formed integrally in the mold by the cushion layer and the thin layer. You do not need to provide a backing cloth.

The skin material is described in more detail. First, in a single extrusion process of forming a thin sheet using TPO (Thermo Plastic Olefin) as a material, it is a technology having a self-expanding layer on its inner side, which maintains the elongation required and becomes a core material. A backing cloth may be provided to enhance the adhesion with the PP resin.

In addition, this skin material is composed of 0.3 ~ 0.9mm thick upper layer and 0.5 ~ 3.0mm thick foamed lower layer or welfare layer additionally. Hardness is 65 ~ 95PHR depending on molding method. Welfare has elongation, adhesion and flame retardancy. The welfare has an elongation of about 300% and the tensile strength is 70 ~ 100Kgf / ㎠ and the thickness is about 1.0 ~ 1.5mm. Welfare above can maintain weight in the range of 120 ~ 160g / ㎡.

 3 is a cross-sectional view for explaining the skin forming structure of the door trim for a vehicle of the present invention. The door trim 30 is composed of a skin layer 31, a base foam layer 32, and a core material 35. As described above, the welfare layer 34 may be optionally included to enhance the adhesion with the core material 35, and the welfare layer 34 is adhered to the substrate by the adhesive layer 33.

4 shows a process flow chart of the present invention. In the production of the skin material, the first process of producing upper and lower extremities (skin layer) and lower extremities in the roll calender 1 having a width of 3 m and about 26 inches, and passing the oven through the oven for preheating the upper and lower extremities, It consists of a 2nd process of carrying out plywood and foaming in the foaming machine 2, the 3rd process of surface-treating using the printing machine 3, and the 4th process of inspecting and packing in the board 4.

Referring to each production process with reference to Figure 5 as follows. In the calender process, which is the first process, the TPO and the pigment and the stabilizer are metered to adjust the amount by mixing and kneading, and after removing the foreign matter, the product is taken from the calender roll (ROLL) 101 and cooling is performed.

In the second process, aging and preheating are carried out. After surface treatment, the solvent is volatilized in a dry oven and the product is cooled.

 The upper and lower limbs are laminated in the plywood device 103 and the sol is applied in the sol coating device 104.

In the foaming process, which is the main process in the present invention, after preheating the product, foaming is performed by heating the product in the foaming oven 105, and then embossing and plywood by heating by an IR heater in the embossing device 106. It cools and surface-coats in the printing press 107 which is a surface treatment apparatus.

In the final process, the product is heated to carry out a backing cloth plywood and then wound up using the winder 108.

The foamless sheet may be injection molded or vacuum molded into a car interior trim skin material.

The following table is a result of measuring the physical properties of the skin prepared according to the process of the present invention and PVC and TPO skin using the existing cushioning material.

Table 1

As can be seen from the table, according to the present invention, in the case of the product foamed by itself in the calender line without adhering the cushioning material, it is lighter than the conventional skin product and the manufacturing cost can be reduced.

By molding the lower extremity on the skin without a separate plywood plywood by the molding method of the present invention, it is possible to effectively reduce the manufacturing cost and product weight while exerting the effect of the existing sheet.

The present invention can be applied to the skin material of automobile interiors such as door trim and pillar trim using foamed type TPO (Thermo Plastic Olefin) or TPU (Thermo PolyUrethane) sheet, and especially PVC due to harmful substances such as heavy metals, dioxins and plasticizers. It is widely used as a substitute material and can be used for recycling. In particular, when the skin itself is foamed with environmentally friendly TPO, there is no shrinkage and distortion after molding. In addition, it has excellent abrasion resistance and scratch resistance, almost no smell and static electricity, excellent trimming in process, and excellent sensitivity of built-in trim skin touch part.

Claims (6)

 A foam comprising an upper limb layer 31 and a self-foaming layer 32 of the same material as the upper limb layer 31, which is formed under the upper limb layer 31 and is laminated after laminating with the upper limb layer 31. Less seat structure. A foamless sheet structure according to claim 1, further comprising a welfare layer (34) below the foam layer (32). The foam sheet structure according to claim 1, wherein the upper layer layer (31) and the foam layer (32) are made of a thermoplastic elastomer (TPE) composed of TPO or TPU. 3. The foam according to claim 2, wherein the thickness of the upper limb layer 31 is 0.3 to 0.9 mm, the thickness of the foam layer 32 is 0.5 to 3.0 mm, and the thickness of the welfare layer 34 is 1.0 to 1.5 mm. Less seat structure. Foam consisting of manufacturing upper limb 31 and lower limb 32 in calender 1, thermo-plywood in foaming machine 2, foaming lower limb 32, and then cooling and surface treatment in printing machine 3 Forming method of the seatless structure. delete

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