JPS6018288B2 - Bathtub manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises press-molding a cloth 1 with at least one of patterns, patterns, colors, etc. and a sheet mold compound 2 to form a bathtub body 3 with the cloth 1 arranged on the inner surface, The present invention relates to a method of manufacturing a bathtub characterized in that a transparent acrylic resin layer 4 is then applied to the surface of the cloth 1.

The purpose is to provide a method for manufacturing a bathtub that can easily produce a bathtub that has a rich three-dimensional effect and a deep pattern on its inner surface. Conventional synthetic resin bathtubs with patterns on the flange surface or inner surface generally have a synthetic resin laminated structure made by a method called a hand lay-up method.

For this reason, it was necessary to perform the following complicated steps in manufacturing. That is, (1) Applying a mold release agent such as wax to a molded product (generally a resin mold) to be formed into the shape of the inner surface of the bathtub.

■ Spray unsaturated polyester resin or the like that forms a transparent gel coat layer, which will be the surface layer of the product, onto the mold or apply it uniformly with a brush. ■ Semi-cure the gel coat layer.

(2) A glass cloth with a pattern, design, etc. printed or transferred thereon, or with a pattern as it is, is laminated with polyester resin or the like on the gel coat layer.

■ On top of the base materials laminated as described above, an intermediate layer made of a surface mat impregnated with resin and a back layer made of a fiber-reinforced plastic layer are sequentially laminated. ■ Attach reinforcing wood to the sides, bottom, etc. to act as reinforcement upon completion. (2) Maintain the above condition in a curing furnace (temperature: 40-6 psi) for about 1 hour to harden it, and then remove it from the mold.

■ Trim the periphery and finish.

As mentioned above, when manufacturing the conventional synthetic resin bathtub with patterns on the flange surface or inner surface, as mentioned above,
■ Molding → curing → molding → curing → finishing requires a lot of man-hours and time.

This results in a bathtub of unstable quality. ■ Adding filler to unsaturated polyester resin, etc. for the intermediate layer and back layer is difficult due to the impregnation of the resin due to brushing, roller coating, and roller pressure, which reduces material costs. becomes higher.

■ Since molds generally use so-called resin molds made of synthetic resin, they require frequent maintenance and repairs. ■
It is almost impossible to degas the middle layer and back layer formed by the conventional hand lay-up method, and if there are residual air bubbles near the surface layer, as the bathtub is used,
The gel coat layer expands and then cracks appear, resulting in an extremely poor appearance.

Techniques for eliminating residual air bubbles, etc. differ depending on the skill level of the operator. There was a drawback.

The present invention solves these conventional drawbacks, and includes:
This is a method for manufacturing a bathtub in which fabric (including nonwoven fabric) is press-molded simultaneously with sheet mold compound (SMC), and patterns can be applied to the inner and outer surfaces of the bathtub.

A detailed explanation will be given below based on the attached drawings.

A cloth 1 (including nonwoven fabric) is given at least one of a pattern, pattern, color, etc. in advance, and is impregnated with a transparent synthetic resin containing no pigment to thicken it. This cloth 1 is cut along the shape of a mold 5 for molding the bathtub body 3, and placed on the mold 5 for forming the bathtub. S onto the spread cloth 1
The MC 2 is loaded, the mold 6 is closed and pressurized by a press molding machine, and the bathtub body 3 is molded. At this time, under normal molding conditions, the fabric 1 is cut by the flow of molten SMC2, so the fabric 1 is cut by the flow of SMC2.
It is necessary to set the molding conditions for MC2 and the press molding machine. To reduce this tensile force, S
The two purposes are to slow down the flow rate of MC2 and to improve the fluidity of SMC2. In order to satisfy this condition, the closing speed of the press molding machine should be slowed down and the hardness of SMC2 should be made soft, but in order to reduce molding defects, SMC2
It is necessary to slow down the curing of the material and form it. ．． It is preferable to use a cloth with a fine weave or mesh, and among these, a nonwoven fabric is particularly preferable, and as an example, a nonwoven fabric of polyester resin is generally used.

In this case, the cloth 1 may be impregnated with a transparent synthetic resin as described above, but since the resin in the SMC is impregnated and becomes transparent, it is not necessarily impregnated with a synthetic resin. Next, an acrylic resin layer 4 is formed on the surface of the cloth 1 of the patterned bathtub body 3 obtained as described above.

In forming the acrylic resin layer 4, an acrylic resin sheet is formed in advance by vacuum forming to match the shape of the inner surface of the bathtub body 3, and holes are formed at arbitrary locations on the inner surface of the bathtub body 3. is raised and suction is applied through the hole to create a vacuum and the molded product is adhered to the cloth 1. Alternatively, the sheet may be vacuum formed using the bathtub body 3;
Make a hole in the tank, seal the bathtub body 3 with a sheet,
Apply suction to create a vacuum and bond at the same time as vacuum forming. In this case, a post-adhesive agent is applied to the bathtub body 3 side. After gluing, the above hole is closed by hand lay-up method or the like. Note that the acrylic resin layer may be colorless or colored as long as it is transparent. Since the hair dye is used in a bathtub, a heat-resistant and strong adhesive is used, such as epoxy, cyanoacrylate, polyurethane, polyester, etc. In the present invention, as described above, a cloth with patterns, patterns, colors, etc., and SMC are pressure-molded to form a bathtub body with cloth arranged on the inner surface, so the complicated process like that for a sub-tub is not required. It is possible to obtain a bathtub body having a pattern etc. in which cloth and SMC are integrated without obtaining the fabric, and furthermore, the presence of the cloth can strengthen the bathtub body.

Moreover, since a transparent acrylic resin layer is applied to the surface of the cloth,
Patterns, etc. can be seen through the acrylic resin layer, making it possible to obtain a beautiful bathtub with a rich three-dimensional effect and depth, and the acrylic resin layer has impact resistance and is resistant to cracks. Another advantage is that the acrylic resin layer protects the printing ink, dye, etc. that form the patterns on the cloth and prevents it from turning brown. The present invention will be explained in detail below using specific examples.

Example 1 Formation of patterned FRP bathtub body As the cloth 1, a nonwoven fabric made of polyester resin is used.

SMC2 has roping glass of 20% with the composition shown in the table below.
~30% was mixed. The cloth 1 is appropriately cut to fit the shape of a mold 5 for forming the inner surface of the bathtub.

The SMC 2 is placed on the cloth 1, and a mold 6 for forming the outer surface of the bathtub is closed and pressure molded using a press molding machine. The molding conditions for pressure molding are as follows. The cloth used here is a non-woven fabric with an elongation rate of 200% in the vertical and horizontal directions, and has a pale yellow floral pattern printed on the surface, and the weight of the cloth is 60%.
It was hot in the evening. Mixing ratio of clear compound ■ Pressing conditions ■ Molding pressure is 500~1000~ compared to conventional 700~
It is preferable to set it somewhat lower than 1000 lightning.

(2) In addition, the closing speed just before the mold 6 hits the molding material (directly above the 20th to 3rd ribs) is set to 0.5 to 2.0 yanagi/sec, which is slightly slower than the conventional 1 to 3 yanagi/sec. ■ Pressure is maintained for 3 to 5 minutes, which is longer than the conventional 2 to 4 minutes. Above■
By the operations of ~■, it is possible to eliminate cutting, twisting, etc. of the cloth 1 during press molding.

@Mold temperature Upper mold 120-13500 (cavity) Lower mold 1
40-15000 (core) mold temperature is the same as that of the slave in this example.

■ SMC2 charge pattern is length 800 x width 70
When forming a bathtub of 0 x height 600 mm, three Isozaki carp and crocodile were used as described above to obtain an FRP bathtub body 3.

Although the printed pattern cloth was adhered to the inner surface and some resin was eluted to the surface, it was incomplete and could not be used satisfactorily. 'B) Forming of an acrylic sheet A 5-rib thick sheet of methyl methacrylate with a slightly ivory color was used.

This sheet was preheated to 13,000 ℃.

The preheated sheet was easily bent, but did not flow and become unmanageable.

On the other hand, make a hole with an IW rib diameter in a place that does not damage the pattern on the bottom of the FRP bathtub body obtained earlier, and attach a pipe from the outside (back side) so that a vacuum can be created when the top is sealed.

Epoxy resin was evenly applied to the inner surface by spraying every 15 days, and heated to 60 qo.

When the temperature of the bathtub body reaches 60 to 6500, a preheated acrylic sheet is placed on the inner surface and the vacuum pressure is increased to 0.5k.
g/Pillow vacuum and mold. At this time, after making sure that the air in the adhesion layer is completely removed even after they are in close contact, stop the suction. After the epoxy adhesive has cured, fill in the holes on the bottom using the hand lay-up method. A bathtub as shown in FIG. 1 was thus obtained.

The resulting bathtub was extremely deep, beautiful, and had a bright floral pattern. Example 2 The pattern created in Example 1 was vacuum-formed from an acrylic sheet using a full-size mold that had the same shape as the inner surface of the FRP bathtub body.

This acrylic molded product was applied with an epoxy adhesive to an FRP bathtub body which had been processed in the same manner as in Example 1, and after applying a vacuum, they were stacked and stuck together, and the adhesive was cured. The bathtubs obtained in Example 1 and Example 2 have a structure in which the FRP part has a thickness of 3 and the acrylic part has a thickness of 2.5, and the JISA
No abnormality was observed in the sand bag impact test specified in 5704.

Reference example: In order to obtain a deep appearance, urethane paint, melamine paint, and polyester paint are each used from 1.0 to 1.0 in place of the acrylic layer.
1.2 Painted with skin thickness but appealed after curing UISA5
Cracks occurred in the sand bag impact test of 704.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the present invention, and FIG. 2 is an explanatory diagram of the manufacturing process. In the figure, 1 is a cloth, 2 is a sheet mold compound, 3 is a bathtub body, and 4 is an acrylic resin layer. Traditional 1st figure, 2nd figure

Claims (1)

[Claims] 1 Pressure mold a cloth with at least one of patterns, patterns, colors, etc. and a sheet mold compound to form a bathtub body with cloth on the inside, and then apply a transparent acrylic resin layer to the surface of the cloth. A method of manufacturing a bathtub characterized by scrubbing.