JPS63176138A - Manufacture of fiber-reinforced synthetic resin molded product - Google Patents

Abstract

PURPOSE:To obtain a smooth surface by compressing and collapsing bubbles, by a method wherein a gel coal layer and gel coat-reinforced layer are cured on a molding mold surface, a main body layer composed of a fiber and thermosetting resin is formed, an air-tight surface layer is formed and then a molded laminated product is pressurized within a pressurizing tank. CONSTITUTION:A gel coat layer 2 is formed by applying a mold release agent to the surface of a molding tool 1, and spraying a material mainly composed of unsaturated polyester resin and a pigment to the surface of the molding tool 1. In succession, a gel coat-reinforced layer 3 is formed by spraying fibers of a mean length of 5m/m uniformly over the said gel coat layer 2 together with the unsaturated polyester resin through a spray gun, and the gel coat layer 2 and gel coat-reinforced layer 3 are cured. A main body layer 4 is formed by spraying fibers of average 38m/m over the surface of the gel coat-reinforced layer 3 together with the unsaturated polyester resin through the spray gun. An air-tight surface layer 5 is formed in succession further by spraying only the unsaturated polyester resin over the whole area. The formed laminated product is left within a pressurizing tank of 8 kg/cm<2> for a minute and then taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a fiber-reinforced synthetic resin molded article of excellent quality with few residual bubbles or cavities in the main body layer.

(Prior art) Conventionally, fiber-reinforced synthetic resin molded products such as bathtubs, waterproof/water pumps, containers, septic tanks, etc. have been made into a wide variety of products because most shapes and structures can be molded using the spray-up molding method. Suitable for small quantity production 1. It is commonly used as a solution. That is,
As shown in FIG. 4, a gel coat layer 2' is provided on the surface of the mold 1 prepared in advance, and a resin such as unsaturated polyester resin is sprayed onto the surface of the gel coat layer 2' on short fibers such as glass fibers to form a main body layer 2'.
It is essential for the so-called manual defoaming work in which air bubbles of various sizes formed in the main body layer are crushed using a defoaming roll or mallet after the formation of the main body layer.

(Problems with conventional technology) However, the spray-up molding method has safety and hygiene issues such as scattering of glass fibers and resin when forming the main body layer, and release of solvents such as styrene monomer contained in the resin. In addition to being forced to perform molding work in unfavorable environments, degassing work is difficult to mechanize, so it is a manual process that relies on experience, which leads to many problems in terms of productivity and quality. Ta.

Therefore, in order to solve these problems, for example, as described in JP-A-60-124237, after forming the main body @4', an F-tight surface M5' is formed, and then an 81-layer product is formed. A technique is known in which the air bubbles in the main body layer are compressed and collapsed by transferring the gas into a pressurized tank (15 Kg/dG), that is, a technique that mechanizes the defoaming operation. This technology is
Although it is an excellent technology that mechanizes defoaming work,
Large air bubbles 6' formed in corners and uneven areas cannot be collapsed, and defoaming rolls in these areas remain labor intensive and are difficult to complete with a complete machine. there were. Furthermore, when the airtight surface layer is pressurized in a pressurized tank, the main body layer hardens and shrinks, but the gel coat layer becomes uneven in the fiber pattern due to the effect of this curing and shrinkage, and the surface is not smooth, resulting in poor appearance. There were also problems with poor quality.

(Means for solving the problem) End 1 solves the problems of the conventional technology as described above by forming a gel coat layer, and forming a gel coat reinforcing layer made of a thermosetting resin and a filler on the surface of the gel coat layer. The gel coat layer and the gel coat reinforcing layer are cured by forming a main body layer made of fibers and a thermosetting resin on the surface of the gel coat reinforcing layer, and the surface of the main body layer consisting of the thermosetting resin is heated. This method involves forming an airtight surface layer made of a curable resin, and then pressurizing the molded laminate in a pressure tank.

In the present invention, a mold release agent may be applied in advance before providing the gel coat layer on the mold.

For the gel coat layer in the present invention, a pigmented thermosetting resin is usually used.

The materials forming the gel coat reinforcing layer in the present invention can be broadly divided into thermosetting resins and fillers. Examples of thermosetting resins include unsaturated polyester resins, vinyl ester resins, and epoxy resins. It is usually used in liquid or viscous form. In addition, fillers include calcium carbonate, tank, clay, silica sand, inorganic fibers such as glass fiber, carbon fiber, boron fiber, alumina fiber, and synthetic fibers such as acrylic, vinylon, polyamide, polypropylene, and polyester. is also used, and its cutting length is 0
, 1 to 10% is usually used, but preferably α is about 1 to 3%. In this case, it is possible to spray the resin and fibers in the form of a mixture.

In addition, these fillers are usually used alone or in combination of two or more. The composition ratio of the filler and thermosetting resin is preferably 20% or less in the resin when the filler is fiber, and 50 to 90% by weight in the resin when the filler is other than fiber. A range of % is appropriate.

In addition, the gel coat layer/in layer does not necessarily have to be provided on the entire length of the long gel coat layer, but may be provided only on a part of the corner or an uneven part, and the thickness thereof is provided on the entire length of the gel coat shaft. In this case, a range of α3 to (L7%) is preferable, and in the case of partial formation, it can be arbitrarily determined depending on the -to shape.

In the formation of the main body layer in the present invention, materials used in ordinary spray-up molding are used, but it is preferable to use at least the same type of resin as the resin used to form the gel coat reinforcing layer. The cutting length of the fiber can be relatively long compared to that of the gel coat reinforcing layer, but if it is too long, bubbles and cavities are likely to be formed, and if it is too short, the strength of the molded product tends to decrease. It is generally good, but on average about 10 to 50% is used.

The airtight surface layer in the present invention serves as a defoaming roll when pressurizing the molded laminate in a pressure tank, and its materials include a grout layer, a gel coat reinforcing layer, and a main body. The resin used to form the fill etc. is the main component. For example, if unsaturated polyester resin is used to form the main body layer, unsaturated polyester resin is also used for the airtight surface layer. The coating thickness is usually about 0.01 to 1%.

In the present invention, the steps of forming each layer, such as the gel coat layer, gel coat reinforcing layer, main body base, and airtight surface layer, may be performed in separate steps, but from the standpoint of increasing productivity, if possible, all of the steps may be performed in series. It is better to make it a continuous process.

For the pressurized tank used in the present invention, a commercially available so-called autoclave can be used as is, but since fiber-reinforced synthetic 5F resin molded products are generally large in size, it is necessary to adjust the pressure tank according to the dimensions of the desired molded product. It may be specially manufactured, and the appropriate pressurizing force is influenced by many factors such as the capacity of the pressurizing tank, the size of the molded product, the thickness of each layer, the material used, the molding speed, and so on. It cannot be said, but the VC must be determined experimentally for each case, and is usually in the range of 4 to 20 to 9/d.

(Function) Since a gel coat reinforcing layer made of a thermosetting resin and a filler is formed on the surface of the gel coat layer, some of the corners and four parts of the irregularities are buried or buried by pressing the button for forming the gel coat reinforcing layer. VC9 with a large radius, the fibers adhere tightly to the mold surface without shorting or sagging during shaping and forming the main body layer, and the gel coat reinforcing layer absorbs the curing and shrinkage effect in the pressurized tank. .

(Example) FIG. 1 shows 1i12. used in the method of the present invention. Figure 1 shows a mold 1 for manufacturing a washing bathtub, which is placed in a prone position on a base (not shown). First, a release agent is applied to the surface of the mold 1, and then, as shown in FIG. 2, a material mainly composed of unsaturated polyester resin and pigment is applied to the surface of the mold 10. The gel coat layer 2 is formed by spraying, and then the fibers guided from the gas roping are cut into an average length of 5%, and the unsaturated polyester resin is evenly sprayed on the gel coat layer 2 with an unsaturated polyester resin from a spray gun. A gel coat reinforcing layer 3 was formed, and the gel coat layer 2 and gel coat reinforcing layer 3 were cured.

At this time, the average thickness of the gel coat reinforcing layer is α5%, and! The weight ratio of fibers in M fat was 15%.

Next, on the surface of the gel coat reinforcing layer 3, the main body layer 4 is formed by cutting 24 fibers taken from the glass roving into an average length of 38% and spraying them together with unsaturated polyester resin + IT# from a spray gun. The second laminate
As shown in the figure, compared to R1 at the corner CK of the gel coat layer 2, the radius of the same R2 of the gel coat reinforcing layer 3 is greatly deformed, and the air bubbles 6 formed in the main body layer 4 are
The dispersed platform was similar to the flat part without being particularly concentrated in the corner part C.

The formed laminate is then placed in a pressurized tank of 8 to 1 q/d.
When the product was left for a minute and then taken out, the airtight surface layer 5 acted as a presser as shown in FIG. 3, the main body layer 4 was compressed, and all the air bubbles 6 that had been formed inside collapsed. Note that 7 is glass fiber.

(Effects) The present invention provides gel coat reinforcement made of thermosetting resin and filler on the surface of the gel coat layer! Even if the molded product has some corners or uneven parts, the gel coat reinforcing layer will fill it in or transform the rounded part into a large rounded part. It adheres closely to the mold surface without making a short pass, and therefore the B 77
The generation of air bubbles and cavities at 14 minutes is suppressed, eliminating the need for defoaming work, making complete mechanization possible, improving productivity, and eliminating the need for hardening and shrinking of the main body layer in a pressurized tank. GELCO)? The Ili strong layer acts as a barrier and its influence does not reach the gel coat layer, making it possible to obtain an excellent molded product with uniform quality overall.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a mold used in the manufacturing method of the present invention, and Fig. 2 is an enlarged sectional view of a main part of an uncured fMK formed by using the improved mold. , Fig. 3 is an enlarged sectional view of the main part showing the same 82-layer product as above after being pressurized in a pressure tank and taken out and completely cured, and Fig. 4 is an enlarged sectional view of the main part showing the conventional example. FIG. 3 is a diagram showing a state in which the sample is pressurized in a pressurized tank and then taken out and completely cured. 1: Molding mold, 2 Nigel coat layer, 3 Nigel coat reinforcing layer, 4: Main body layer, 5: Airtight surface layer, 6: Air bubbles, 7: Glass fiber

Claims (1)

[Claims] 1. When manufacturing fiber-reinforced synthetic resin molded products by the spray-up molding method, a gel coat layer is formed on the surface of the mold, and a gel coat reinforcing layer made of a thermosetting resin and a filler is formed on the surface of the gel coat layer. The gel coat layer and the gel coat reinforcing layer are cured, a main body layer made of fibers and a thermosetting resin is formed on the surface of the gel coat reinforcing layer, and a main body layer made of the thermosetting resin is coated on the surface of the main body layer consisting of the thermosetting resin. 1. A method for producing a fiber-reinforced synthetic resin molded product, which comprises forming an airtight surface layer, and then pressurizing the molded laminate in a pressure tank.