JPS58205718A - Preparation of synthetic resin skin body - Google Patents

Abstract

PURPOSE:To obtain a skin body providing a thin skin only at necessary parts and free from material loss by a method wherein only necessary parts of a force in heated up to the melting temperature of powdery molding material, and compressed air is ejected into the force to remove antigelling molding material. CONSTITUTION:Temperature ragulating pipes 11 are stuck only to necessary parts of the outer surface of a force 2 and a reservoir tank 4 of powdery molding material 10 is provided so that it can be lifted by a lift. Jet pipes 8 of compressed air are provided at the opening part of the tank 4 and louvers 9 are fixed on the lower side. The force 2 is filled with the powder material 10, and excessive powder material 10 is recovered in the tank 4, compressed air is jetted to remove antigelling powder from the force surface. The tank 4 is dropped, the temperatures of the necessary parts of the force 2 are lifted and gelled film 13 is melted and hardened to take the molding from the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an outer skin by a slush molding method using a powdered synthetic resin molding material, particularly a powdered thermoplastic synthetic resin molding material. Methods for forming skin bodies such as pads include (a) vacuum forming method, (b) rotational molding method using plastisol or powder material, and (c) slush molding method using plastisol or powder material. .

(c) Spray skin molding methods using urethane paints, etc. are known, but each of these methods has a poor yield of materials needed as products for official materials, and vacuum forming methods are generally used. Then, 40 to 70% by weight 9 In the rotational molding method, 2
The situation is that 0 to 50% by weight is lost, 20 to 40% by weight in the slush molding method, and 40 to 80% by weight in the spray method.

By the way, among the above methods, in the slush molding method which has a relatively good yield, Japanese Patent Publication No. 54-10581 has recently been published as a method for further improving the method, in which temperature control piping is placed in the first region and the second region. A method has been proposed in which the thickness of unnecessary parts of the product is made as thin as possible by separately controlling the temperature.

However, this method uses a liquid material, and because it is a liquid material, it is premised that it is not possible to prevent the formation of a thin film on all unnecessary parts of the mold, so try to make the wall thickness of unnecessary parts as thin as possible. However, it is still far from perfect in terms of material yield.

In addition, the mold used in this method is a thin-walled mold made of electroformed nickel, etc., with temperature control piping on the outer surface, and heat of different temperatures is applied to the first and second regions. The generation of distortion due to the flow of the medium has a very negative effect on the service life of the mold.

In view of the above-mentioned actual situation, the present invention solves the above-mentioned drawbacks and
It is an object of the present invention to provide a method for manufacturing a skin body by an improved slush molding method, which can obtain a material yield close to 0.00% and greatly improve the life of the mold.

Another object of the present invention is that in the liquid slush method,
It is difficult to form a uniform thin film due to uneven thickness caused by liquid flow, drops, etc. at the stage of discharging excess sol, and furthermore, in rotary molding using liquid or powder materials, it is difficult to increase the thickness at acute corners. The object of the present invention is to solve the problem of the need for thick-walled molding as a whole because it is difficult to form a thin-walled skin, and to easily obtain a uniform and thin-walled skin body.

Therefore, the feature of the present invention that achieves the above advantages is that the temperature control area of the mold is set to the first temperature control area. 2. To maintain the mold temperature in unnecessary parts below the gelation temperature of the molding material by passing a heat medium at a constant temperature only to the necessary parts without dividing into second part, and to prevent the occurrence of distortion in the mold. Then, a powder material is used as the molding material, and after expelling the excess material, compressed air is further injected into the mold to completely eliminate the non-gelling material, so that no thin film is formed in unnecessary areas. A method for manufacturing a synthetic resin skin body by slush molding.

Hereinafter, specific embodiments of the method of the present invention will be explained with reference to the accompanying drawings.

FIG. 1 shows an outline of a skin manufacturing apparatus for carrying out the manufacturing method of the present invention, and in the figure (1) is a mold device, in which an open mold (2) is set on a mold support member (3). ing.

This mold support member (3) is fixed to a pair of opposing support plates (6) (6) by a shaft (7) as shown, and freely rotates around the axis A-A. And the above axis (7)
A temperature control pipe 01) for regulating the temperature of the mold (2) is inserted from the mold (2), and is provided in close contact with only the necessary portions of the outer surface of the mold (2).

On the other hand, in the downward direction of the mold device (1), between the support plates (6), a powder molding material (10) and a glue reservoir tank (4) are placed on top of the lifting machine (5). It is set up so that it can be lifted at any time by a lifting machine (5) to a position where it comes into close contact with the mold (2).

Fig. 2 is a cross-sectional view of the reservoir tank (4) in Fig. 1 marked F, and as shown in the figure, a compressed air injection pipe (8) is connected to the opening of the reservoir tank (4). A looper (9) is provided along the longitudinal direction of the tank (4), and a looper (9) is provided on the lower side of the tank (4).
(hereinafter referred to as powder material) has a function of controlling charging into or discharging from the glue reservoir tank (4).

Next, the details of carrying out the method for manufacturing a skin body of the present invention using the above-mentioned molding apparatus will be explained with reference to FIG.

In the illustrated embodiment, the safety pad surface material is made of granular vinyl chloride resin having an average particle size of 30 microns.

First, a soft PVC powder material 00) manufactured using a Henschel mixer according to a conventional method was mixed into 1 noser 7-tank (
4) Fill the inside. In this case, the Lizano Kuichi tank (4
) is configured to have a capacity equivalent to the mold capacity or at least greater than the capacity of the mold (2).

Then, a heat medium, for example, hot oil, is flowed through the temperature control piping 01) of the mold to maintain the temperature of the necessary portions of the mold (2), excluding the unnecessary portion (b), at 120 to 125°C. (Figure 3 (a)) Next, the mold device (1) is rotated about the axis A-A to a position where the opening of the mold (2) faces the opening of the reservoir tank (4). . In addition, the above-mentioned mold temperature 12
0 to 125°C is usually the gelation temperature of PVC powder material 00), but the mold temperature in the unnecessary part (b) where the temperature control piping (11) is not provided is 50 to 60°C, and the gelling temperature is 0 to 125°C. After completing the above operations, the lifting machine (5) carrying the reservoir tank (4) is raised to take the mold (2) and remove the reservoir tank (4). After clamping the two in that state, attach the lifting machine (5
) is lowered. (Fig. 3 (b)) Then, with the compressed air injection pipe (8) and the loop (il) provided in the reservoir tank (4) closed, the mold device (1) and the reservoir tank are closed. (4
) is rotated and held at an angle that allows the powder material Qo) to fall into the mold (2) by gravity, and the mold (2) is filled with the powder material α0) using the louver (9) ( Figure 3 (c)
), close the louver (9) again.

After filling the powder material α0) in this way, the mold device (1) and the reservoir tank (4) are rotated again to an angle that allows the powder material α0) to fall into the reservoir tank (4) by gravity. After holding it, open the Root Cooler (9) and empty the excess powder material into the reservoir tank (4).
At the same time, compressed air is injected into the mold (2) to remove non-gelled powder from the mold surface.

In this case, a gelled thin film 03) is formed and adhered to the necessary portions of the mold due to the heated temperature. (3rd
)) Then, the lifting machine (5) is raised, the clamp is released and the reservoir tank (4) is lowered to its original position, and then inside the temperature control pipe 01) of the mold (2). The temperature of the heating medium is raised to 200~220°C to melt and harden the gelled thin film 03) in the mold (2), and then the temperature of the heating medium is lowered to 60~220°C. Cool to 70°C. (Third Crystal (E)') “After performing a series of operations in this way, the mold device (1) is then rotated to the product ejection position and the molded product 04) is removed from the mold (2). Make a mold.

(FIG. 3(f)) Thus, the steps in the present invention are completed, and the molded product 0 -> that is, the skin body is manufactured.

Although the powder material shown in the above embodiments is a vinyl chloride powder material, various powder materials made of thermoplastic resins such as polyethylene and polypropylene can also be used in the present invention.

In that case, it is natural to select a gelling temperature suitable for each powder material. Furthermore, the shape of the mold is not necessarily limited to the illustrated example, and it goes without saying that modifications may be made as appropriate within the scope of the purpose.

The present invention consists of the method described above, and has various technical effects as described below.

(1) The mold has temperature control piping only in the necessary parts, so that the necessary parts can be kept at the melting temperature of the powder material, and the unnecessary parts can be kept at a temperature lower than that. As a result, it becomes difficult for powder material to adhere to unnecessary parts, eliminating the need for trimming the skin, reducing the cost of piping to the mold, and naturally distributing the temperature of the mold. Therefore, it is possible to prevent the occurrence of distortion and dramatically extend the service life.

(2) After discharging the powder material from the mold to the reservoir tank, compressed air is blown into the mold so that there is no excess powder material in the mold.
Close to 0.00% of unnecessary material can be recovered, and furthermore, combined with the temperature control piping provided in the mold, no thin film is present in unnecessary parts.

(3) By closely fixing the reservoir tank containing the powder material to the mold and rotating them, the powder material can be introduced into the mold and discharged from the mold into the reservoir tank. There is no material scattering and material loss can be prevented.

(4) Thus, from the above points, the manufacturing method of the present invention has much superior effects and is highly practical compared to conventional methods.
Not only is it industrially advantageous, but it is also economical.

This is a method that is expected to be implemented in terms of quality as well.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a skin body molding device used to implement the manufacturing method of the present invention, Fig. 2 is a sectional view taken along the line B-B in Fig. 1, and Fig. 3 (a) to (e) are diagrams showing the method of the present invention. FIG. 3 is a schematic explanatory diagram showing the manufacturing process of each process. (2)...Mold, (4)...Reservoir tank. (8)・・・・・・Compressed air jetting piping, (1o)・
...Powdered molding material. (11)・・・・・・Humidity control piping, 02)・・・
...Unnecessary part. “Fang (he) 11

Claims (1)

[Claims] 1. By using a mold in which temperature control piping is arranged only in the necessary parts of the outer surface, and by passing a heating medium at the required temperature through the piping.
Then, only the necessary parts of the mold are heated to the melting temperature of the powdered molding material, and the mold temperature of the remaining unnecessary parts is kept below the gelling temperature of the molding material, and the powdered molding material is poured into the mold. The excess molding material is then discharged, and compressed air is blown into the mold to completely eliminate the non-gelled molding material in the mold, forming a skin with a molten thin film only on the necessary parts of the mold. 1. A method for producing a synthetic resin skin body, which is characterized in that while forming a body, no thin film is formed on unnecessary parts. 2. Using a mold in which temperature control piping is arranged only in necessary parts of the outer surface, and a server tank that accommodates powder molding material and can be moved into and out of contact with the mold, the heat medium is allowed to flow through the piping. The necessary parts of the mold are heated to the melting temperature of the powdered molding material, and then the reservoir tank containing the powdered molding material is closely fixed to the mold, and by rotating both together, the reservoir tank is heated to the melting temperature of the powdered molding material. The powdered molding material is put into the mold, and then both are rotated again to discharge the powdered molding material from the mold into the reservoir tank, and further compressed air is blown into the mold. Excess powdered molding material in the mold is discharged to form a skin made of molten film only on the necessary parts of the mold, but on the other hand, the above-mentioned skin is not formed on unnecessary parts of the mold. A method for producing a synthetic resin skin body characterized by the following.