JPS606780B2 - Patterned plastic molded product and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic molded product such as a bathtub with a pattern and a method for manufacturing the same.

Traditionally, patterns have been applied to FRP (reinforced plastic) bathtubs using the spray-up method, in which patterned cloth woven from glass fibers is layered on the surface of a mold, and resin is sprayed from the surface side, and the hand-lay-up method. However, this method requires a large number of manufacturing steps, tends to produce an uneven surface layer, and the quality of the product is largely dependent on the skill of the worker.

However, another method for manufacturing FPR bathtubs is to use a lower male mold and an upper female mold to fill the gap between them.
The so-called SMC material (SeatMo
A typical example is the so-called SMC method, in which the RP is melted while heating a pair of molds with a ldingcompo skin d), diffused to a uniform thickness between both molds, cured, and then removed from the molds. There is a press molding method.

However, according to this method, it is difficult to apply an arbitrary pattern to the surface of the molded product. An object of the present invention is to solve the above problems and provide a molded product with an arbitrary pattern and a method for manufacturing the same.

The main feature of the present invention is to use a patterned fabric which is molded with a patterned fabric interposed therebetween and whose one side has been raised in advance to enhance physical bonding force in addition to chemical bonding force.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The polyester fiber pattern cloth 3 on which the pattern has been printed is brushed on only one side using a napping machine. Using this single-sided raised fabric, sew it into a bag shape with the raised side facing outward to match the shape of the bathtub. Next, the patterned cloth 3 sewn into a bag is placed over the male mold 1, which is constantly heated at 80°C to 150°C, so that the inside of the bag is in contact with the mold surface, and then the mold is placed over it. After installing the necessary and sufficient amount of FRP SMC material to form the base layer as much as possible along line 1,
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 figure, the resin of the FRP material passes through the grains of the patterned cloth 3 and transfers to the opposite side of the cloth 3, forming a thin transparent resin layer 5. After that, the resin begins to harden, and after a predetermined period of time, the mold is opened and the molded product is taken out. What is particularly noteworthy here is that by using the raised pattern cloth in the plastic molded product manufactured in this way, physical adhesion occurs between the fluff and the polyester resin, and the adhesion between the two is significantly reduced. This is a significant improvement.

In FIG. 2, 4 indicates the FRP material base layer. In addition to woven fabrics, patterned fabrics include woven fabrics or silk fabrics such as knitted fabrics, laces, braids, and other nonwoven fabrics, and also include fabrics made of filament yarns and spun yarns.

As mentioned above, the fibers used for patterned fabrics are required to have appropriate strength, heat resistance, and dyeability. Other examples that meet these requirements include natural fibers such as cotton and silk, and man-made fibers such as organic fibers such as cotton, nylon, and vinylon. is used. Plastic materials include unsaturated polyester resin, fillers, pigments,
Short or cut glass fibers are impregnated in a solution sufficiently mixed with a mold release agent, etc., and the viscosity is thickened using magnesium oxide etc. to make it a little softer, but other reinforced plastics and plastics are also used. B-stage block plastics are also used.

If a thin paper-like transparent surface mat 6 made by intersecting long glass strands is interposed on the surface side of the patterned body (opposite side of the base layer 4), the resin adsorption properties such as water absorption properties can be improved. Therefore, the resin infiltrates the surface mat 6 through the holes of the pattern 3 and forms a transparent layer on its surface. Therefore, on the surface of the pattern, a transparent layer consisting of the mat, the resin layer infiltrated with the mat, and the resin layer on the surface of the mat is formed at the same time as molding, making it extremely efficient. It maintains wear and corrosion resistance, and also has the effect of adding depth to the handle. The surface mat is required to have properties such as transparency that allows the pattern of the patterned cloth 3 to pass through, adsorption of molten resin, wettability of molten resin, and heat resistance such that it does not melt at mold temperature. As the structure of the mat that satisfies this requirement, a cloth-like material such as a woven fabric or a non-woven fabric, a perforated sheet, a film-like material, a paper-like material, etc. are used. Furthermore, in order to form the transparent resin layer 5,
A clear gel coat resin may be applied to the mold 1 in advance, or the patterned cloth 3 may be impregnated with the resin in advance.

Here, if the radius of curvature of the surface of the corner portion along which the patterned fabric of the mold follows is set to at least 15 ribs, the grains of the patterned fabric are widened by the corner and become rough, thereby preventing the pattern from changing.

In addition, if the edge of the patterned fabric is held by the cutout part la of the mold, the patterned fabric will not move even if the resin of the FRP material flows. Also, overlapping of cloth (particularly at corners) is prevented.

The bag can be made according to the shape of the bathtub by attaching it with a synthetic resin adhesive or by welding it, in addition to sewing it.

In addition to the above embodiments, surface patterning 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 placed upside down. The method of the present invention is not limited only to bathtubs, but also applies to container-shaped molded products such as boats, tanks, and other small containers made of plastic or FRP materials, as well as flat and curved surfaces such as bathtub aprons and vanity sinks. This also applies to shaped molded products.

As described above, the present invention makes it possible to add any pattern to a T-molded product by molding a plastic material with a patterned cloth interposed therebetween. Since it is molded with the surface facing the base layer, the fluff provides a physical bonding effect between the patterned fabric and the polyester resin, improving the adhesion between the two and preventing the patterned fabric from peeling off after molding.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the manufacturing method of the present invention, and FIG. 2 is an enlarged longitudinal end view of the main parts of the bathtub. 1...Male mold, 2...Female mold, 3...
...Patterned cloth, 4...FRP material substrate, 5...Transparent layer. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A plastic base layer, a patterned cloth located on the surface side of the plastic base layer and having the base layer side raised, and a transparent resin formed on the opposite side of the base layer by filling the grains of the patterned cloth. A patterned plastic molded product characterized by comprising a layer. 2. In a method in which a plastic material is interposed between a pair of heated molds, the molds are closed, the material is melted under pressure, and then hardened and molded. Molding is performed by placing the plastic material on the one mold side heated to a lower temperature so that its raised surface faces the other mold side, and interposing the plastic material between the patterned cloth and the other mold. A method for producing a patterned plastic molded product characterized by: