JPH05200885A - Manufacture of synthetic resin molded product - Google Patents

Abstract

PURPOSE:To save the labor of grinding the periphery of a drain outlet on the rear face of a bathtub. CONSTITUTION:A synthetic material is applied onto a molding tool 1 by the hand layup method to form a synthetic resin layer 3, and then a force 5 provided with a smooth face 5b is mounted on a required site of said synthetic resin layer 3 before the layer is cured, and the layer is cured to form a flat face on the rear face of a molded product. Therefore, the grinding process by a grinder applied heretofore is not necessary, and the leakage prevention at a connecting section is secured in the case a drain pipe is connected with.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a synthetic resin molded article such as a bath made of fiber reinforced plastic (hereinafter referred to as "FRP") by a hand layup method.

[0002]

2. Description of the Related Art As means for manufacturing synthetic resin molded products,
A manufacturing method using a hand layup method is known. The hand lay-up method is often used when manufacturing a bathtub made of FRP, and the process is described as follows.

First, a mold release agent is applied to the surface of a mold which has been cleaned, and then a gel coat resin is sprayed and cured by heating or the like to form a gel coat layer.
Next, a glass fiber sheet and a synthetic resin are laminated on this gel coat layer, and defoaming and curing are performed. After a while,
Reinforcement material, bottom plate, legs, etc. are attached, and glass fiber sheet and synthetic resin are laminated. Then, after defoaming and curing this, and removing from the mold, the desired FRP bath is obtained.

[0004]

As shown in FIG. 5, in the bath 10 manufactured in this way (however, the legs and the like are not shown), the surface 10a in contact with the molding die 20 is formed smoothly. However, the back side 1 that is exposed during use
No. 0b has a concavo-convex surface because it is formed by laminating glass fiber sheets with a synthetic resin.

By the way, the portion 11 of the bathtub 10 provided with the drainage port is formed so as to project in advance to the back surface 10b side, in other words, to be recessed when viewed from the front surface 10a side,
After demolding, the site 11 is perforated to form a drainage port. Then, when installing the bathtub 10, a drain pipe is connected to the drain port thus formed from the back surface 10b side. However, as described above, since the back surface 10b of the bathtub around the drainage port is an uneven surface, water leakage occurs between the bathtub 10 and the drain pipe. Moreover, if you just put packing between them,
It is difficult to prevent water leakage. Therefore, conventionally, the rear surface around the drainage port is polished by a grinder to make it smooth, which is troublesome.

[0006]

The present invention provides a method for solving the above-mentioned conventional drawbacks, which is characterized in that a synthetic resin material is applied to the surface of a mold by a hand lay-up method. In the method for producing a molded article by coating, a synthetic resin layer is formed on a molding die, and before curing, a pressing die having a smooth surface is attached to a required portion of the synthetic resin layer to form a molded article. A flat surface is formed on the back surface.

[0007]

According to the method of the present invention, for example, the bathtub is
When manufacturing with RP, after confirming the overall shape, on the back surface of the drain pipe connection part etc. where smoothness is required,
Before the curing, a pressing die is attached and then it is cured. Therefore, if the pressing die is removed after the synthetic resin material is cured, a flat surface is formed at the relevant portion. Therefore, there is no need to grind the periphery of the drain port with a grinder as in the prior art, and water leakage is surely prevented.

[0008]

The details of the present invention will be described below with reference to the drawings illustrating the embodiments. FIG. 1 shows an intermediate state of the process of manufacturing the bathtub A by FRP. Even when the method of the present invention is applied, the procedure is the same as the conventional procedure until the final curing step. That is, a mold release agent is applied to the surface of the mold 1 that has been cleaned, a gel coat resin is sprayed to form a gel coat layer 2, and then a glass fiber sheet and a synthetic resin are laminated on the gel coat layer 2, After defoaming and curing, a reinforcing material, a bottom plate, and a footboard (all not shown) are attached, and then a glass fiber sheet and a synthetic resin are laminated to form a synthetic resin layer 3 having a constant thickness. The process up to the step of defoaming is the same as the conventional one.

The present invention is characterized in that after the overall shape of the bathtub A is determined as described above, before the synthetic resin material is hardened, the pressing die 5 is mounted by pressing it against the drainage port forming portion 4. Have. As shown in FIG. 2, the pressing die 5 used here is formed in a disc shape having a concave portion 5a in the center and an annular smooth surface 5b around the concave portion 5a.
Vent holes 5c are formed in a. The material of the pressing die 5 is not particularly limited, such as synthetic resin, ceramic, metal, etc., but it is required that it can be easily removed from the molded product.

When the pressing die 5 is pressed against the drainage port forming portion 4 of the bath A, the smooth surface 5b of the pressing die 5 causes a flat surface around the drainage port, that is, a region corresponding to the connection portion of the drainage pipe. Is formed. At this time, the synthetic resin material of the drainage port rises into the recess 5a at the center of the pressing die 5, and the air in the recess 5a is discharged to the outside from the ventilation hole 5c. Can be in close contact with.

If the pressing die 5 is made of a transparent material, whether or not a flat surface is surely formed at a predetermined portion when the pressing die 5 is attached to the synthetic resin layer 3,
It can be confirmed whether or not air bubbles remain between the smooth surface 5b of the pressing die 5 and the synthetic resin layer 3. This is useful when manufacturing a product in which the synthetic resin layer 3 is thin.

In this way, the final curing step such as heating is performed with the pressing die 5 mounted on the back surface of the bath A. Finally, after removing the pressing die 5 from the cured synthetic resin layer 3, the molded product is released from the molding die 1 to obtain the target bath A. In this bathtub A, the connection portion of the drainage pipe is formed on a flat surface, so that it is not necessary to perform grinder processing, and if the drainage pipe is connected via packing, it is possible to prevent water leakage between the two. Is.

By the way, it is sometimes necessary to provide a flat surface on the back surface of the bathtub other than around the drainage port.
For example, as shown in FIG. 3, in a floor pan P in which a bathtub A, an apron portion B, and a washroom portion C are integrally formed, the overflow pipe 6 may be attached to the back surface of the bathtub A. In this case, the portion to which the overflow pipe 6 is attached must be formed on a flat surface, but as shown in the drawing, the apron portion B is integrally formed on the outside of the bath A, so that it is difficult to attach the pressing die 5. Therefore, in this embodiment,
As shown in FIG. 4, a holder 7 in which the length of the bolt 7b can be adjusted by rotating the nut 7a is inserted between the bath A and the apron portion B, and the push mold 5 is attached at one end of the holder 5. It was decided to press and hold the required part in A.
In this state, after the hardening treatment is performed, the holder 7 and the pressing die 5 are removed, so that a flat surface can be provided in the attachment portion of the overflow pipe 6 in the bath A.

In addition, when it is necessary to form a flat surface on the back surface of the bathtub, air is mixed in the bathtub when the hot water circulation pipe is connected to the bathtub when installing the bathtub in the bathroom. There may be mentioned a case where various pipes are connected to the outer surface of a so-called bubble bath for circulating hot water.
The present invention can also be applied to the production of various synthetic resin molded articles such as waterproof pans and water tanks, in addition to the case of producing bathtubs by FRP. Furthermore, the specific embodiments of the present invention do not prevent appropriate modification depending on the implementation situation.

[0015]

EFFECT OF THE INVENTION In the method for producing a synthetic resin molded article according to the present invention, before the synthetic resin layer is cured, a pressing die is attached to a required portion of the molded article to form a flat surface in advance. Since a molded product is obtained by curing the resin, there is no need to perform a conventional grinding treatment by a grinder process. Therefore,
Work man-hours are reduced and production efficiency is improved. Moreover,
Since a flat surface can be surely formed at a required portion, for example, when connecting a drainage pipe or the like, it is possible to reliably prevent water leakage at the connecting portion.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the main parts of an embodiment in which the present invention is applied to a bathtub manufacturing method.

FIG. 2 is a view showing a pressing die used in the present invention,
(A) is a perspective view seen from the back side, and (B) is a front sectional view.

FIG. 3 shows a floor pan integrally formed with a bathtub, an apron part, and a washing part, (A) is a perspective view, and (B) is a perspective view.
FIG. 4 is a vertical cross-sectional view of the main part of the drawing, showing a state in which an overflow pipe is attached to a bathtub.

FIG. 4 is a view showing an embodiment of another aspect of the present invention, and is a main part showing a procedure for forming a flat surface at a mounting portion of the overflow pipe on the back surface of the bath when the bath and the apron are integrally formed. FIG.

FIG. 5 shows a conventional manufacturing process of a bathtub,
(A) is a perspective view showing a state in which a synthetic resin layer is formed on a molding die, and (B) is a longitudinal sectional view thereof.

[Explanation of symbols]

A ... Bathtub 1 ... Mold 2 ... Gel coat layer 3 ... Synthetic resin layer 4 ... Drainage port formation site 5 ... Push mold 6 ... Overflow pipe

Claims (1)

[Claims] 1. A method for producing a molded article by applying a synthetic resin material to the surface of a molding die by a hand lay-up method, the method comprising forming a synthetic resin layer on the molding die, and then curing the synthetic resin layer. A method for producing a synthetic resin molded article, characterized in that a pressing die having a smooth surface is attached to a required portion of a layer to form a flat surface on the back surface of the molded article.