JPS6328775B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a so-called resin injection method in which a synthetic resin liquid is injected into male and female molds that are clamped with a glass base material interposed therebetween, and the glass base material is impregnated with this to obtain a molded product. Concerning improvements in molding methods.

Conventionally, in the resin injection molding method, a preform preformed from chopped strands in a shape close to that of the product has been mainly used as a glass base material.

Therefore, in order to carry out such a method, expensive equipment such as a preformer for making the preform is required, and since a process for forming the preform is involved, there are many manufacturing steps, which increases the manufacturing cost. There was a problem.

Therefore, in order to eliminate the above-mentioned drawbacks, it is possible to use mat instead of preform as a glass base material. For example, when using swirl mat (container strand mat), the product surface can be made smooth Not only is it impossible to do this, but swirl mat is expensive as a glass base material.Although the above-mentioned problems of swirl mat can be solved when chopped strand mat is used, it does not flow easily due to injection of resin. Both of them have advantages and disadvantages, such as the problem that they are concentrated in some parts of the product and there are parts of the product where there is no glass base material, and it has been difficult to use mat instead of preform as the glass base material. .

In view of the current situation, the present invention uses a combination of chopped strand mat and swirl mat instead of a preform as the glass base material in the resin injection molding method, and uses chopped strand mat at least on the surface side of the product. By arranging the strand mat, all of the above-mentioned problems associated with the conventional resin injection method are attempted to be solved.

Hereinafter, the present invention will be explained in detail based on Examples.

In the figure, A is a male mold and B is a female mold, and when they are fitted and clamped, a cavity in the shape of product C is formed between them.

Then, in the open state of the male mold A, after applying a mold release agent to the molding surface a and applying a gel coat,
A chopped strand mat 1 is placed along the molding surface.

Next, the swirl mat 2 is placed on top of the chopped strand mat 1, and this process is repeated as necessary to obtain the desired thickness.

In the illustrated example, there are three layers: chopped strand mat 1, swirl mat 2, and chopped strand mat 1, but it is also possible to have three or more layers.

In addition, if the product C to be molded is a product that does not need to have a smooth surface on either the inside or outside, such as a bathtub or water tank, the glass base material placed on the side corresponding to the surface is as shown in the illustration. It is not necessarily necessary to use the chopped strand mat 1 as shown in the figure, and the swirl mat 2 does not have to be placed on the front side.

Subsequently, a mold release agent is applied to the molding surface b of the female mold B, and this is fitted into the male mold A and the mold is clamped.

At this time, if the surface to be molded by the molding surface b of the female mold B of the product C is to be a smooth surface, the molding surface b of the female mold B is coated with a gel coat after applying a mold release agent. Furthermore, although the female and male molds B and A are not shown in the drawings, the mold clamping may be performed by a mold clamping press, bolt tightening, or the like, and any means may be used.

After that, a synthetic resin liquid such as unsaturated polyester is injected from the injection port 3 provided in the female mold B, and the cavity is filled with this, and the glass base material consisting of the chopped strand mat 1 and the swirl mat 2 is injected. Impregnate.

The resin injection described above completely exhausts the air between the glass substrates and between the glass substrate and the molding surfaces b and a of the female and male molds B and A, and The process is continued until the resin overflows from an air vent hole (not shown) provided in either mold B or mold A, and then stopped.

After resin injection is stopped, the resin is heated for a required time or left at room temperature to wait for the resin to harden, and after hardening, the mold is demolded to obtain a product C, completing the molding.

As described above, the present invention uses chopped strand mat and swirl mat as the glass base material instead of a preform in the resin injection molding method, so the glass base material is less expensive than when using a preform. Not, but
It does not require expensive and large-scale equipment such as a preformer, and therefore it is possible to reduce production costs, and also to omit labor and time for preform production, thereby shortening and simplifying the manufacturing process. I can do it.

In addition, since the pine used as the glass base material is a combination of chopped strand pine and swirl pine, the amount of relatively expensive swirl pine can be reduced compared to using only swirl pine.
The cost is reduced accordingly, and since the chopped strand pine gets caught in the swirl pine and is prevented from flowing by resin injection, there are no inconveniences such as the product being concentrated in certain areas. It can be distributed evenly throughout the product, and there is no risk of causing problems in product strength.

In addition, chopped strand mats are placed on the surface of the product, especially in areas where smoothness is required, ensuring that those areas are formed with a smooth surface, which improves the appearance compared to conventional methods. It's not inferior.

Thus, the intended purpose can be achieved.

[Brief explanation of the drawing]

The drawings are schematic vertical cross-sectional views showing the embodiment of the method for manufacturing reinforced plastic molded products according to the present invention according to the manufacturing process. The injection process, Figure 3 shows the demolding process, and Figure 4 shows the product. A...Male type, B...Female type, 1...Chopped strand pine, 2...Swirl pine.

Claims (1)

[Claims] 1 In a method for producing a reinforced plastic molded product, in which a synthetic resin liquid is injected into male and female molds that are clamped with a glass base material interposed, and the glass base material is impregnated with this liquid and hardened to obtain a molded product, the glass base material may be used as the molded product. A method for manufacturing a reinforced plastic molded product, characterized in that a pulled strand pine and a swirl pine are used in combination, and the former is placed at least on the smooth surface side of the product.