JPS5845938B2 - Method for manufacturing reinforced plastic patterned molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing FRP molded products such as bathtubs with patterns.

Traditionally, FRP (reinforced plastic) bathtubs are manufactured using a so-called SMC material (SeatMoldin) that uses a female lower mold and an upper female mold to fill the gap between the two in the form of an FRP sheet.
The FRP was melted and diffused to a uniform thickness between the pair of molds while heating the pair of molds with a compound (g compound) interposed between the two molds, and then taken out from the molds and cooled.

According to such conventional methods, it was not possible to create a pattern on the surface of the molded product.

An object of the present invention is to provide a method for applying a pattern to the above-mentioned FRP molded product at the same time as press molding.

The molding method of the present invention involves placing a patterned cloth on one of a pair of male and female molds that are constantly heated to a predetermined temperature, placing an FRP material on top of the patterned cloth, and pressing both molds together. Essential.

An embodiment of the present invention will be described in detail below based on the drawings.

As shown in the figure, a pair of molds with curved mold surfaces are used to mold a molded product with a curved surface.

A bag-shaped patterned fabric 3 is placed over the male mold 1, which is constantly heated below the melting temperature of the patterned fabric 3, over the curved mold surface, and the bathtub is placed over the male mold 1 so as to follow the mold 1 as much as possible. Necessary and sufficient amount of FRP SMC material 4 for formation
After placing the molds in an overlapping manner, the female mold 2 is placed on top, and the male and female molds are closed and pressurized.

This operation melts the FRP material, and as shown in the second diagram,
The resin in the FRP material passes through the mesh of the patterned cloth 3 and transfers to the surface of the cloth to form a thin transparent resin surface layer 5, at which point the resin begins to harden.

After a predetermined period of time has elapsed, the mold is opened and the molded product is taken out.

As the front Be patterned cloth 3, a cloth woven using spun yarn such as nylon or polyester cotton having strength that does not deform or tear during press molding and heat resistance that does not melt is used, and various patterns are printed on this. , cure thoroughly with steam etc.7
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Spun yarn has many voids between its constituent fibers and has noticeable fuzz on the yarn surface, so it has excellent dyeing stability and is also useful for stabilizing the adhesion of resin.

In addition, FRP materials are made by impregnating short cut glass fibers in a solution sufficiently kneaded with unsaturated polyester resin, fillers, pigments, mold release agents, etc., and thickening it with magnesium oxide etc. to make it slightly softer. is used, but other reinforced plastics are also used.

Example: A pattern was applied to a cloth woven using 100 d polyester spun yarn by gravure printing, and the patterned cloth, which had been cured for heat resistance, was sewn in a bag to fit a bathtub, and the male die 1 of the mold was heated to 120 to 150°C. Then, a predetermined amount of SMC material was placed to cover 70 to 80 parts of the mold surface area, and the mold was closed and heated and pressurized. After the FRP material was heated and hardened, it was taken out.

In addition to the above-mentioned embodiments, the surface pattern can also be applied to the outer surface of the bathtub by attaching a patterned cloth to the inner surface of the female mold.

In this case, the male and female molds are arranged upside down.

The method of the present invention is not limited only to bathtubs;
It is also applicable to boats, tanks, and other small containers made of P material.

Patterned fabrics include woven fabrics, knitted fabrics, lace, plaited fabrics, and other non-woven fabrics such as woven fabrics or net-shaped fabrics.

As mentioned above, the fibers used for patterned fabrics are required to have appropriate strength, heat resistance, and dyeability. Other examples of natural fibers that meet these requirements include cotton and silk, and artificial 1am fabrics such as cotton and nylon vinylon.

In addition to sewing, the bag may be made by attaching it with synthetic resin adhesive or by welding.

As described in detail above, the present invention enables FRP to be molded integrally with FRP material by interposing a patterned cloth on the surface of a molding die.
It became possible to create any pattern on the inner or outer surface of the molded product.

Since spun yarn was used as the raw material for the patterned fabric, the patterned fabric itself has good dyeability, and even if a thin transparent resin surface layer is formed on the surface of the molded product through the grains of the patterned fabric, the pattern remains clear. A molded article having the following properties is obtained.

Furthermore, the fluff of the spun yarn strengthens the adhesion of the resin, prevents the resin surface layer from peeling off, and increases the durability of the patterned surface of the molded product.

In addition, since the patterned fabric is not pre-impregnated with resin, the patterned fabric can be easily brought into contact with the curved mold surface, making the molding process quick and easy, and the quality of the finished product is also good. be.

Furthermore, since the patterned fabric is shaped like a bag, it is possible to create a beautiful and complete pattern without wrinkles in the patterned fabric, pattern breakage due to thread breakage, or overlapping of the fabric (especially at corners). Manufacturing the body has become much easier.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing the manufacturing method of the present invention, and FIG. 2 is an enlarged sectional view of the bathtub wall. 1...Male mold, 2...Female mold, 3...Patterned cloth, 4
...FRP material, 5...resin surface layer.

Claims (1)

[Claims] 1. In order to mold a molded product with a curved surface, a reinforced plastic material is interposed between a pair of vertically opposing male and female heated molds having curved mold surfaces, the molds are closed, and the material is pressurized. In the method of melting and curing molding, a bag-shaped patterned fabric made of spun yarn is placed along the curved mold surface of either of the male and female molds, and the patterned fabric is heated to a temperature lower than the melting point of the patterned fabric. 1. A method for producing a patterned reinforced plastic molded product, comprising heating a mold and interposing the reinforced plastic material between the patterned cloth and either of the molds.