JPS584623B2 - 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, as another method for manufacturing FRP bathtubs, for example, a lower male mold and an upper female mold are used to fill the gap between the two.
So-called SMC material (Seat
The FRP is melted while heating the pair of molds with a molding compound (molding compound) interposed between the two molds, and the FRP is diffused to a uniform thickness between the two molds, hardened, and then removed from the molds using the so-called SMC method, other BMC methods, and plastic molding methods. There are mechanical molding methods such as remodeling methods.

However, according to these methods, it has been difficult to create any desired pattern on 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.

Therefore, the present invention involves molding with a patterned body such as patterned cloth,
The gist is that a mixture of calcium carbonate and pulverized and refined feldspathic minerals is used as a filler in the plastic base layer, and the weight ratio of the mixture is 80/20 to 0/100.

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

A polyester fiber pattern cloth 3 with a printed pattern is sewn into a bag shape to match the shape of the bathtub.

Next, a bag-shaped transparent surf ace mat 6 that matches the shape of the bathtub is placed over the entire surface of the bathtub forming part of the lower male mold 1 that is constantly heated at 80°C to 150°C, and the patterned cloth is placed on top of it. 3 is placed, and both ends are held between the cutouts 1a of the mold.

Then, after placing a necessary and sufficient amount of FRP SMC material for forming a bathtub along the mold as much as possible from above, the upper female mold 2 is covered from above, and these male and female molds are closed. Apply pressure.

As the surface mat 6, a transparent material made of long glass strands crossed to form a thin paper-like material having a thickness of 0.1 to 0.5 mm is used.

This operation melts the FRP material, and as shown in the second diagram,
The resin in the FRP material moves to the surface of the cloth 3 through the grains of the patterned cloth 3 and reaches the mat 6.

Here, the mat 6 exhibits adsorption power such as water absorption to the resin, and this is thought to be due to capillary phenomenon due to the texture of the cloth.

Therefore, a large amount of resin passes through the mesh of the patterned cloth 3 to the mat 6.
The resin reaches the surface while infiltrating through the fiber gaps of the mat, and forms a transparent resin layer 5.

4 is an FRP material base layer. After that, the resin begins to harden,
After a predetermined time has elapsed, the mold is opened and the molded product is taken out.

As the patterned cloth 3, in addition to the above, a cloth woven from organic fibers such as nylon and vinylon, and natural fibers such as cotton, which are heat resistant to the extent that they do not deform or tear during press molding and do not melt, is used. .

In addition, as plastic materials, unsaturated polyester resin,
Glass fibers cut into short pieces are impregnated in a solution sufficiently kneaded with fillers, pigments, mold release agents, etc., and made slightly soft by thickening with magnesium oxide, etc., but other reinforced plastics and plastics are also used. B-stage block plastics are also used.

As the filler in the plastic material, a mixture of calcium carbonate and pulverized and refined feldspathic minerals is used, and the weight ratio of the mixture is 80/20 to 0/100.

Figure 3 shows the relationship between the amount of filler (feldspathic mineral CaCO3) added and the Izod impact value.
The amount of filler per 100 parts by weight of resin is 100.
The values are 90, 80.70.

As shown in the figure, if the proportion of feldspathic minerals is high, the molded product becomes brittle, so the amount is limited.

Examples of typical chemical components and general properties of the feldspar minerals are listed below.

The surface mat 6 is required to have properties such as transparency that allows the pattern of the patterned cloth 3 to pass through, adsorption of molten resin, infiltration of molten resin, and heat resistance such that it does not melt at mold temperature.

As mat structures that meet this requirement, cloth-like bodies such as woven fabrics and non-woven fabrics, perforated sheets, film-like bodies, and paper-like bodies are used.

Incidentally, although the Surf Ace mat 6 is not necessarily required, if it is placed on the surface of the patterned body, the resin will infiltrate the mat through the grains of the patterned body due to its resin adsorption properties, forming a transparent resin layer on the surface. Form.

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, which is extremely efficient, and these thick layers provide long-term resistance to hot water and abrasion. , it maintains its corrosion resistance and also has the effect of creating depth in the handle.

In addition to woven fabrics, patterned fabrics include woven fabrics or net-shaped fabrics made of knitted fabrics, lace, plaited fabrics, and other non-woven fabrics.
It also includes fabrics made from filament yarns and spun yarns.

As mentioned above, the fibers used in 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 cotton, nylon, and vinylon. .

In addition, 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.

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 arranged upside down.

The method of the present invention is not limited to bathtubs, but can also be applied 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.

Since the present invention is molded with a patterned cloth interposed as described above,
Any pattern can be easily applied, and since a mixture of calcium carbonate and finely divided feldspathic minerals is used as a filler in the plastic material, the mineral has excellent low coloring power and whiteness. The properties of this material allow the pattern of the molded product to appear clearly, and the property of low resin absorption allows for high filling, resulting in significant savings in the cost of coloring pigments.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing the manufacturing method of the present invention, Fig. 2 is an enlarged vertical end view of the main part of the bathtub, and Fig. 3 is a graph showing the relationship between the amount of filler added and Izod impact value based on experimental results. It is. 1...Male mold, 2...Female mold, 3...
...Patterned cloth, 4...FRP material base layer, 5...
...Resin layer, 6...Surf Ace mat.

Claims (1)

[Scope of Claims] 1. The plastic base layer includes a plastic base layer, a patterned body such as a patterned cloth or a patterned sheet, and a resin layer formed on the reaction side of the base layer by filling the eyes of the patterned body with resin. A mixture of calcium carbonate and pulverized and refined feldspar minerals is used as a filler, and the weight ratio of the mixture (calcium carbonate/feldspar minerals) is 80/20 to 0/100.
A plastic molded product with a pattern. 2 In a method of curing and molding by interposing a plastic material between a pair of heated molds, closing the molds and heating and melting the material, the patterned object such as patterned cloth or patterned sheet is heated at a temperature lower than its melting point. The above-mentioned plastic is interposed between the patterned body and the other mold, and the plastic is placed on the side of one mold that is heated to A method for manufacturing a patterned plastic molded product, characterized in that the mixing ratio with minerals is 80/20 to 0/100.