JPH01196331A - Molding of interior trim material - Google Patents

Abstract

PURPOSE:To obtain a soft-feeling interior trim material with a low cost, by arranging a base material and a foaming slush skin having a foaming layer before foaming respectively on the molding face of an upper mold and that of a lower mold, both having a specified clearance, clamping both molds and foaming their content to fill the clearance. CONSTITUTION:An electric template (lower mold) 2 is heated to about 240 deg.C, and vinyl chloride powder and foaming vinyl chloride powder and successively put thereinto and recovered to form a foaming slush skin 8. The thickness of a foaming layer 7 may be provided to be sufficient to fill the clearance 3 of the mold. On the other hand, a thermoplastic resin sheet 9 is heated in advance and fixed on a heated upper mold 1, and then it is clamped with a lower mold 2. The whole is kept in the temperature of about 190-200 deg.C and is left as it is for about 1min to foam it the foaming layer 7 to a foamed layer 7' at the same time adhere the foaming slush skin 8 and a base material 9 together. After that, a desired pillar 5 is made by cooling and releasing the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for molding interior materials, particularly soft interior materials for automobiles and the like.

(Prior Art) The following methods are known for molding interior materials for automobiles that require a soft feel, such as pillars, instrument panel pads, and door trim uppers.

(1) Integral foam molding A molding method in which a skin material and a core material are set in a mold, a urethane foam material is injected into the material, and the material is foamed and integrated (for example, JP-A-59-49947, etc.).

■ Mold coat A molding method in which paint is sprayed on the cavity surface of the mold to form a surface layer, and then urethane material is injected between it and the core material to integrate it.
"Production Terminology Dictionary" edited by Toyota Engineering Society, p. 450 (198,
5 years)).

(2) A molding method in which an adhesive is applied onto a base material for tension molding, and a skin material having a foam layer is bonded thereon by vacuum molding (for example, JP-A-62-111721, etc.).

However, among the above molding methods, method (1) involves many molding steps and has very low productivity, and methods (2) and (2) require expensive molds due to foaming under high pressure.
Each of these methods has problems in that the vacuum equipment is expensive and the material yield is poor. Both of the above methods use expensive materials such as a urethane foam material or a skin material having a foam layer, so there is a problem in that the product cost increases.

In addition, injection molding, flock molding, stamping molding, and the like, which can be formed at low cost, do not provide products that satisfy the softness required for interior materials.

Foaming slanche molding is a molding method that has been increasing in recent years because interior materials having a thin skin such as soft polyvinyl chloride can be easily obtained. In this method, a foamed slush skin having a foam layer obtained by foamed slush is integrated with hard urethane in a mold (for example, as disclosed in Japanese Patent Laid-Open No. 16232/1983 and Japanese Utility Model Laid-Open No.
2-166009, etc.).

[Problems to be Solved by the Invention] In the above-mentioned foam slush molding, when molding a foam slush skin, a foamable powder is usually deposited on the solid vinyl chloride layer that will become the skin, and then the powder is heated with hot air. It is then heated and foamed to form a foam layer.

Since the foaming at this time is performed in an open mold, subtle irregularities occur on the surface of the foam layer of the skin of the foamed sludge 1. Therefore, when bonding base materials, if the base material cannot follow the irregularities, irregularities will occur on the surface of the molded product, resulting in defects, so hard urethane is usually used as the base material to prevent this. However, hard urethane has a problem of high raw material cost and therefore high manufacturing cost.

The present invention is intended to solve these problems, and aims to provide an improved method of foam slush molding, and in particular, a molding method that can produce interior materials with a sufficiently soft feel at a low cost. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, the method for molding an interior material of the present invention involves forming a base material and a foamed slush skin having a foam layer before foaming on a surface having a certain clearance. It is characterized in that it is placed on the mold surfaces of a mold and a lower mold to close both the upper and lower molds, and then the foam layer of the foamed slush skin is foamed to fill the clearance of the mold.

In the interior material molding method of the present invention, the foamed slush skin having a foam layer before foaming, which is placed in the upper mold or the lower mold, means the foamed slush skin before what is generally called "post-heating", for example, vinyl chloride. A foamed layer made of powder or sol of foamed vinyl chloride is adhered onto a solid layer made of powder or sol of foamed vinyl chloride, etc., and the foamed layer is foamed by post-heating.

Here, the thickness of the solid layer is appropriately selected, but is preferably 0.35e* to 0.6 m, and the foam layer has a thickness sufficient to fill the clearance between the upper and lower molds after foaming. Attach the amount.

Furthermore, the base material is not limited to the conventional hard urethane, but may also be a thermoplastic resin sheet.

Here, as the thermoplastic resin sheet, for example, polypropylene (including those containing wood flour, talc, or glass fiber, and TC, PP) can be used, and preferably has a thickness of 0.
．． 5 to 3.0 Peng.

Furthermore, after the mold is closed, the foam layer of the foamed slush skin is foamed to fill the clearance of the mold. This can be done by heating the entire upper and lower molds, but preferably by heating the heated base material and/or Alternatively, it is carried out using the heat of a heated mold in which the substrate is placed.

[Effect]

The method for molding the interior material of the present invention is to foam the foamed slush skin within the clearance created by closing the upper and lower molds, and at the same time bond the foamed slush skin to the base material. The layer and base material are bonded reliably and firmly.

Because this method is used, there are no restrictions on the material used as the base material, and not only hard urethane but also cheaper thermoplastic resin sheets can be used as the base material, making it possible to mold interior materials at a lower cost. .

Furthermore, in the present invention, foaming of the foamed slush skin is not only carried out by heating the entire body after the mold is closed, but also by the heat of the preheated base material and/or the mold in which the base material is set, so that the molding time is reduced. It is also possible to shorten the time.

〔Example〕

Next, the present invention will be explained in more detail based on Examples, but the present invention is not limited thereto.

In this example, first, the mold shown in Fig. 1 was used.
The process of forming the pillar 5 shown in FIGS. 2 and 3 will be explained.

An electroforming mold (lower mold) 2 for slush molding is heated to about 240° C., and vinyl chloride powder and foamed vinyl chloride powder are sequentially charged and recovered to form a foamed slush skin 8. As a result, a solid layer 6 of vinyl chloride powder with a thickness of 0.50 m and approximately 1.0 m thick is formed as the skin.
A foam layer 7 made of foamed vinyl chloride powder and having a thickness of m is formed.

The thickness of the foam layer 7 may be as long as it is present in an amount necessary to finally fill the mold clearance 3.
is 5 mm in this example, so the thickness of the foam layer 7 was set as described above. This is because the foam layer made of foamed vinyl chloride powder is generally about 2.5 times the foaming ratio after foaming, and the zero foaming ratio, which is determined by taking into consideration this and the thickness of the solid layer and the base material, is about 1 to 4 times. It can be set with .

The vinyl chloride powder and foamed vinyl chloride powder used here are for slush molding, and for example, those manufactured by Nippon Zeon Co., Ltd. or Sumitomo Chemical Co., Ltd. can be used.

The temperature of the lower mold 2 when the vinyl chloride powder is collected is about 200''C. On the other hand, the base material is a thermoplastic resin sheet (here, a fiber-filled polypropylene sheet with a thickness of 2°0++n, Hypervia manufactured by Kingdom Manufacturing Co., Ltd.). )9 to about 200
This is heated to a temperature of 200° C., fixed to the upper mold 1 which has also been heated to about 200° C., and the mold is closed with the lower mold 2.

At this time, the upper and lower molds 1.2 are fixed with clamps 4. If necessary, heat the upper and lower molds in a clamped state to maintain the entire temperature at 190 to 200'C), leave for about 1 minute to foam the foam layer 7 to form N7°, and add the foamed Slanche skin 8 and base material. Glue 9. Thereafter, the desired pillar 5 is obtained by cooling and demolding.

Pillar 5 obtained in this way has a soft feel.
Each material is firmly bonded.

Furthermore, the manufacturing cost of this pillar 5 has been significantly reduced compared to conventional methods. When comparing this with the case of the method of the present invention as 1 and the case of the conventional method, it is 1.5 to 2.0 for stretch molding and 1.3 for integral foam molding.
from 1.6 to 1.6, from 1.2 to 1.2 from foamed slanche molding.
5 and mold coat molding was 2.5. This result shows that the method of the invention can be carried out at very low cost.

Similar operations were used to mold the instrument panel pad and the door trim upper, which, like the pillars, could be molded at low cost, had a soft feel, and each material was firmly bonded.

(Effects of the Invention) As explained in detail above, the method for molding interior materials of the present invention has a sufficient soft feel required for interior materials, and also allows the foamed slanche skin and base material to be firmly adhered. This made it possible to provide interior materials.

Furthermore, since this method allows the use of a thermoplastic resin sheet as a base material, molding can be performed using a material that is much cheaper than conventional hard urethane, and manufacturing costs can be reduced.

Moreover, this interior material molding method foams the foamed slush skin within the clearance between the upper and lower molds, so dimensional accuracy and foam layer thickness can be reliably controlled, so the interior material can be molded with a high yield.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a mold structure used in an embodiment of the method for molding interior materials according to the present invention, and FIG. 2 is a perspective view of a pillar molded by the method for molding interior materials according to the present invention. FIG. 3 is a sectional view taken along the line II in FIG. 2. In the figure, 1... Upper die 2... Lower die 3... Clearance 8... Foamed slush skin 9... Thermoplastic resin sheet Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A base material and a foamed slush skin having a foam layer before foaming are placed on the mold surfaces of an upper mold and a lower mold with a certain clearance, respectively, and both the upper and lower molds are closed, and then the foamed slush skin of the foamed slush skin is placed on the upper and lower mold surfaces with a certain clearance. A method for molding an interior material, the method comprising foaming to fill the clearance of the mold.