JPS59167236A - Manufacture of composite plastic tank - Google Patents

Abstract

PURPOSE:To efficiently form a tank by a method in which a tank base is molded by a blow molding method, and a fiber-reinforced plastic layer is covered on the outside of the tank base. CONSTITUTION:A thermoplastic pipe 1 in a softened state by heating is inserted into a tank mold 2 of iron plate in such a way that one end of the pipe 1 is protruded from the tank mold 2. Both ends of the pipe 1 are closed with stoppers 3 and 4. An air supply tube 5 is connected to the air hole 4A of the stopper 4, compressed air is supplied into the pipe 1 for blow molding and the protruded end 1A of the pipe 1 is pressed through the stopper 3 according to the degree of expansion of the pipe 1. After cooling, the tank base 11 is removed out of the mold 2, and a fiber-reinforced plastic layer 12 is covered on the outside of the tank base 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite plastic tank used, for example, for storing and transporting chemicals.

This type of tank usually has an inner wall made of thermoplastic, which has chemical resistance but poor mechanical strength, and an outer wall made of fiber-reinforced plastic, which has poor chemical resistance but high mechanical strength. be.

Conventionally, in order to manufacture this blood tank, a tank base serving as an inner wall was first manufactured by welding and assembling thermoplastic plates, and the outer periphery of the tank base was coated with a fiber-reinforced plastic layer. However, welding and assembling the tank base is mostly done manually, requiring skilled workers, and is extremely inefficient.

The present invention aims to improve the above-mentioned conventional drawbacks and efficiently manufacture this type of tank, and its main feature is to manufacture the tank base by expansion molding.

The present invention will be explained in detail below.

The present invention consists of the following five steps.

1. Process of heating and softening the thermoplastic plastic pipe 1゜2. Insert the thermoplastic plastic pipe in the heated and softened state into the tank mold, and at L7, one end of the thermoplastic plastic pipe comes out from inside the tank mold. Step 2゜3, Step 3゜4 of sealing both ends of the thermoplastic pipe with plugs, applying pressure fluid inside the thermoplastic pipe while pressing the outside end to perform expansion molding. Step 4 to obtain a tank base. 5. Step 5 of coating the outer periphery of the tank base with a fiber-reinforced plastic layer Step 1. For example, polyvinyl chloride, polyvinyl
A pipe made of thermoplastic plastic such as polypropylene, polypropylene, or polytetrafluoroethylene is heated to a temperature higher than its softening temperature in a heating furnace or the like to soften it.

Step 2. As shown in Figure 1, thermoplastic plastic pipe (1) in a heat-softened state (hereinafter simply referred to as pipe (
1) into the tank mold (2) made of iron plate.

At this time, one end of the pipe (1) should be out of the tank mold (2). This end is called the outer end (1)A.

Step 3. In this case, both ends of the pipe (1) are sealed with plugs (8) and (4) as shown in Figure 2. Plug body (4)
A ventilation hole (4) A is provided in the.

Step 4. In this case, the air injection pipe (5) is connected to the vent hole (4) A of the plug body (4), and pressurized air is applied to the inside of the pipe (1) to form an expansion, and at the same time, the outside end of the pipe (1) is 1
) Press A through the stopper (3) in line with the expansion of the pipe (1). By pressing the outside end of the pipe (1) in accordance with the expansion of the pipe (1) as described above, the inner thickness of the molded product is prevented from becoming thinner.

This situation is shown in FIG. Thus, the tank base αD
is obtained, which is removed from the mold after cooling.

After demolding, a hole (11) A is formed at the bottom of the tank base αη based on the insertion of the plug (4), so the hole (11) A is closed by the bottom cover (6) as shown in FIG. will be closed.

However, if the end of the pipe (1) is gripped with a chuck or the like instead of the stopper, a tank base with a closed bottom can be obtained, and the stopper itself may be used as the bottom cover.

In addition, when removing the tank base (1'f),
4) exhaust the pressurized air in the tank base GI).

Furthermore, if desired, hot water, low pressure steam, a hot spot, etc. are then sealed in the tank base 0D to perform annealing and cooling.

Step 5. As shown in Fig. 5, a fiber plastic layer (2) (hereinafter p
Rpitw) is #simulated. F RP layer (by mixing fibers such as glass fibers and carbon fibers with resin raw materials such as vesicular polyester, diallylphthalate, and styrene and curing the mixture with a peroxide etchant, an azo etchant, etc.) Generally, the FRP layer α is formed by impregnating a roving made of the above-mentioned fibers in the above-mentioned wood raw material and winding it around the outer periphery of the tank base Ql). In order to improve the adhesion between the tank base 0η and the FRPIiFla2, an epoxy resin, acrylic resin, polyester resin, or the like may be applied as a primer to the outer periphery of the tank base αη.

In this way, a composite glass tank (10) having an inner wall made of thermoplastic and an outer wall made of FRP is obtained, but if desired, the upper lid, liquid inlet 04, liquid outlet αO, etc. are attached to the tank α0.

Since the tank base of the present invention is manufactured by expansion molding of thermoplastic pipes, there is no need for laborious manual work such as welding and assembly, which requires skill, and the manufacturing process is greatly simplified. be shortened. During expansion molding, the end of the pipe that protrudes from the tank mold is pressed in line with the expansion of the pipe, so a tank base with uniform wall thickness is obtained, and the outer circumference of the tank base thus obtained is By reinforcing it with FRP, a composite glass tank suitable for storing and transporting chemicals can be manufactured.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention, and FIG. 1 shows step 2. FIG. 2 is a side sectional view showing step 3. FIG. 3 is a side sectional view showing step 4. FIG. 4 is a side sectional view showing step 4. FIG. 5 is a side sectional view of the tank base obtained in step 1 with the eave cover attached, and FIG. 5 is a side sectional view of the finished product. In the figure, (1)...Thermoplastic pipe, (
2)...tank type, (3), (4)--plug, (5)...pneumatic tube, O(J...-composite glass tank, (11)... ...tank base, (l
... FRP layer patent applicant Aron Kasei Co., Ltd. Figure 1 Figure 2 Figure 24

Claims (1)

[Claims] Step 1 of heating and softening a thermoplastic pipe: inserting the thermoplastic pipe in a heated and softened state into a tank mold, so that one end of the thermoplastic pipe comes out from inside the tank mold. Step 2: Sealing both ends of the thermoplastic pipe 3:
゜ Step of pressing the outer end of the thermoplastic plastic pipe and applying pressure fluid inside to perform expansion molding to obtain a tank base; 4゜ Step of coating the outer periphery of the tank base with a fiber-reinforced plastic layer; 5゜ or more. A method for manufacturing a composite plastic tank comprising steps 1.2.8.4.5.