JPH07125083A - Manufacture of frp tube - Google Patents

Abstract

PURPOSE:To manufacture an FRP tube having a resistance to corrosion on its inner face by winding a resin-impregnated belt-shaped material with filler on a cylindrical mold, and winding a reinforcing continuous fiber body thereon, feeding heat-setting resin onto the reinforcing continuous fiber body and heat setting it. CONSTITUTION:A mold release film 14 is wound on a steel belt 24 wound helically on a rotating cylindrical mold, and unsaturated polyester resin 21 containing a curing agent is fed thereon. Then a glass paper 16 with glass flakes 19 on its surface is wound thereon with the upper accumulated surface facing on the mold side so that the glass flakes 19 are not dropped. Further, a glass roving cloth 28 as a reinforcing continuous fiber body is used for impregnating a wound material with unsaturated polyester resin 21 containing a curing agent and wound thereon. The wound material is carried to a curing oven 26 and cured, and then cut into the optional length by a cutter 29. An FRP tube not to be deteriorated by a chemical or the like can be manufactured by the process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an FRP pipe.

[0002]

2. Description of the Related Art Conventionally, an FRP pipe manufacturing apparatus of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-265733.

When a pinhole or a crack is generated on the inner wall surface of the FRP pipe due to aging or the like, the FRP pipe manufactured by the conventional FRP pipe manufacturing apparatus is glass of the FRP pipe due to the chemical contained in the water flowing down into the FRP pipe. Fiber deteriorates. As the deterioration progresses, the hardness of the pipe decreases,
When the FRP pipe was buried in the soil, there was a problem that the pipe was damaged by the external force of earth pressure.

To cope with such a problem, after forming a pipe, a corrosive layer is formed on the inner surface of the pipe by laminating and molding a reinforced resin in which a filler such as glass flakes and a resin are mixed with a roller or a trowel. It has been known.

[0005]

However, in laminating molding with a roller, a trowel or the like, it is necessary to appropriately roughen the inner surface of the pipe with a hand grinder or the like in order to obtain the adhesive strength between the reinforcing fiber and the pipe. , Workability is poor. In addition, it is a manual work of the operator and the appearance after molding is poor. Further, in the case of a pipe having a small diameter, there is a problem that the work cannot be performed because the worker cannot enter the pipe.

Therefore, it is conceivable to provide a corrosion resistant layer on the inner surface of the pipe at the same time when the pipe is molded. However, in that case, when the filler and the resin such as glass flakes are mixed, the mixture becomes putty and the viscosity becomes extremely high, so that a fixed amount of the reinforced resin in which the filler and the resin such as glass flakes are mixed is supplied on the mold. Is difficult. Further, when supplying a reinforced resin in which a filler such as glass flakes and a resin are mixed onto the mold, the glass flakes are oriented in different directions in different directions, so the glass flakes should be parallel to the inner surface of the tube. Orientation, that is, it is necessary to orient at right angles to the direction of entry of the chemicals contained in the flowing water, but it is difficult to stretch the resin due to its high viscosity, and glass flakes and the like are not oriented.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for manufacturing an FRP pipe having excellent corrosion resistance on the inner surface of the pipe.

[0008]

A method of manufacturing an FRP pipe according to the present invention comprises a step of attaching a filler to a resin-impregnated strip,
A process of winding a resin-impregnated strip with a filler on a cylindrical mold, a process of winding a reinforcing long fiber body, and a thermosetting resin supplied to the reinforcing long fiber body. And a subsequent step of heating and curing.

In the step of supplying the thermosetting resin, it may be applied when the reinforcing long fiber body is wound, or the reinforcing long fiber body impregnated with the thermosetting resin may be wound. . The thermosetting resin used in the present invention is not particularly limited,
Epoxy resin, polyester resin, polyurethane resin,
Phenolic resin, acrylic resin, furan resin, etc. are used. The long fiber body for reinforcement is not particularly limited,
Glass strands, glass rovings, etc. are used.
If necessary, a curing agent, an accelerator and the like may be mixed with the thermosetting resin before use.

As the filler, glass flakes, mica flakes, graphite flakes, alumina, zirconium oxide, silica, silicon carbide and the like are used. The filler is preferably treated with a silane coupling agent in order to obtain a more corrosion resistant effect. The filler content is preferably 5 parts by weight or more and 100 parts by weight or less with respect to the resin.
If it is less than 5 parts by weight, it is difficult to obtain a sufficient corrosion resistance effect.
If it is 0 parts by weight or more, the filler is exposed on the inner surface of the tube and the appearance is inferior and the moldability is poor.

As the resin-impregnated belt-like material, glass paper, glass cloth, woven fabric made of organic fibers, non-woven fabric and the like are used. The method of applying the filler to the resin-impregnated strip is to pass the resin-impregnated strip into the tank in which the filler is deposited and place the filler on the resin-impregnated strip, or to put the filler on the resin-impregnated strip. A method of spraying on an object is preferable.

[0012]

According to the method for producing an FRP pipe of the present invention, since the step of winding the resin-impregnated band-like material on which the filler is attached is wound around the cylindrical mold, the inner surface of the pipe is protected against corrosion at the same time when the pipe is molded. A layer can be provided, and it is not necessary to manually provide a corrosion-resistant layer after forming the pipe.

Further, when the resin-impregnated belt-like material having fillers such as glass flakes is wound around the mold, the fillers are in the form of flakes so that they overlap each other and are parallel to the inner surface of the pipe, that is, to the water flowing down. It is oriented at a right angle to the entering direction of the contained chemicals. Next, when the thermosetting resin is supplied, the thermosetting resin permeates the resin-impregnated strip to impregnate the filler and is cured. Therefore, F
A corrosion resistant layer is simultaneously formed on the inner surface of the RP pipe.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which glass paper is passed through a tank in which glass flakes are accumulated. Figure 2
Shows the continuous molding method of the FRP pipe. Example 1 1 is a filler attachment device. Glass flake as filler (Nippon Sheet Glass Co., Ltd., RCF-600) average thickness, 4μ
m, average width, 10 to 4000 μm, glass paper (30 g / m ² , 95 mm width) was used as a resin-impregnated strip. First, the glass paper is passed through the tank 18 in which the glass flakes are accumulated. The width of the opening 17 of the tank 18 is provided so that the glass paper 16 is not caught when the glass paper 16 passes therethrough. If the thickness is thin, the deposition amount of the glass flakes 19 is small, and if the thickness is thick, it is large. The thickness of the opening 17 can be arbitrarily adjusted. The content of the glass flakes 19 in the corrosion resistant layer on the inner surface of the tube was adjusted to 20 parts by weight with respect to the resin.

Next, the continuous molding device 2 will be described.
This device is equipped with a cylindrical mold that rotates about a rotary shaft 23, and an endless steel belt 24 is spirally wound around the mold, and is formed by the steel belt 24 by the rotation of the mold. The mold surface is designed to move forward. And the steel belt 24 that has reached the open end of the mold
Has a structure in which it returns to its original position through the center of the mold and is wound around the mold again. One end of the mold faces the curing furnace 26.

The release film 14 is formed on the steel belt 24.
After winding (made of PET, thickness: 25 μm), resin 21 in which MEK peroxide and cobalt naphthenate are added to an iso-unsaturated polyester resin is supplied in order to better impregnate the glass flakes 19 with the resin. Next, the upper surface of the glass paper 16 on which the glass flakes 19 are deposited is wound on the mold side so that the glass flakes 19 do not fall. At that time, the glass flakes impregnated with the resin are defoamed by the rubber pad 27. This is because the glass flakes impregnated with the resin have a very high viscosity, and there is a possibility that defoaming may not be sufficiently achieved only by the drawing force by winding the reinforcing long fibrous body in the next step. At this time, the glass flakes 19 are oriented and the corrosion resistance is further improved.

A glass roving cloth 28 is used as a reinforcing long fiber body, and a resin 21 in which an MEK peroxide and cobalt naphthenate are added to an iso type unsaturated polyester resin is impregnated and wound. At this time, the resin 20 impregnated in the glass roving cloth 28 permeates the glass paper 16 and impregnates the glass flakes 19 to be simultaneously formed. Next, after being conveyed to the curing furnace 26 and cured, it was cut into a desired length by a cutter 29 to obtain a sample. The sample had a uniform corrosion resistant layer formed on the inner surface. In the state where this sample was sliced into 30 cm width and flattened by 5% of the inner diameter, 5 w% sulfuric acid was retained by plates at both ends of the tube so that the inner surface of the tube was immersed. Then, the time until a crack was formed on the inner surface of the pipe was measured. Result 1000
After 0 hours, there was no abnormality.

Comparative Example 1 The same as Example 1 except that no filler (glass flake) was used. Results of the same experiment as in Example 1 2
After 700 hours, the bottom of the tube cracked.

[0019]

The FRP pipe manufacturing method of the present invention is such that when the resin-impregnated band-shaped material having fillers such as glass flakes is wound around the mold, the fillers are flaky and overlap each other, so that the inner surface of the pipe is Parallel to, that is, substantially perpendicular to the inflow direction of the chemicals contained in the flowing water. Next, when the thermosetting resin is supplied, the thermosetting resin permeates the resin-impregnated strip to impregnate the filler and is cured. Therefore, it is possible to manufacture an FRP pipe that is not deteriorated by chemicals contained in the flowing water.

A corrosion resistant layer can be mechanically provided on the inner surface of the pipe at the same time when the pipe is molded. Therefore, it is possible to manufacture a pipe having a small diameter that an operator cannot enter, and the workability is excellent.

Furthermore, it is not necessary to roughen the inner surface of the pipe with a hand grinder or the like, and the appearance of the inner surface of the pipe is good.

[Brief description of drawings]

FIG. 1 is a state diagram in which glass paper is passed through a tank in which glass flakes are accumulated.

FIG. 2 is an explanatory view showing a continuous molding method of an FRP pipe.

[Explanation of symbols]

1 Filler Adhering Device 16 Glass Paper (Resin Impregnating Band) 17 Opening 18 Tank 19 Glass Flake (Filler) 2 Continuous Forming Device 21 Resin Discharge Port 23 Rotating Shaft 24 Steel Belt 26 Curing Furnace 27 Patch Plate 28 Impregnating Resin Glass roving cloth (long fiber body for reinforcement) 29 Cutter

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Claims (1)

[Claims] 1. A step of applying a filler to a resin-impregnated strip, a step of winding a resin-impregnated strip with a filler on a cylindrical mold, and a step of winding a reinforcing long fibrous body. And a step of supplying a thermosetting resin to the reinforcing long fibrous body, and a step of subsequently heating and curing the FRP tube.