JPH03243333A - Manufacture of fiber-reinforced thermoplastic resin pipe - Google Patents

Abstract

PURPOSE:To fuse an internal layer pipe and a fiber composite body excellently by using a chlorinated vinyl chloride resin having chlorine content lower than that forming the internal layer pipe as a thermoplastic resin constituting the fiber composite body. CONSTITUTION:A chlorinated vinyl chloride resin to which a heat stabilizer and a lubricant additional matter are added is melted and kneaded by an extruder 1, and an internal layer pipe 3 is extrusion-molded by a mold 2. A fiber composite body 4 is wound out on the outer circumference of the internal layer pipe 3 from a first winder 5, hot air is injected by a hot air type heating apparatus 6, and a chlorinated vinyl chloride resin in the fiber composite body 4 is heated and melted, and fused with the internal layer pipe 3, thus forming a first layer reinforcing layer. A second layer reinforcing layer is wound in the opposite direction to the first layer by a second winder 5, thus similarly molding a tubular body 11. The chlorine content of the chlorinated vinyl chloride resin in the fiber composite body 4 is made lower than that of the chlorinated vinyl chloride resin of the internal layer pipe 3, and the chlorinated vinyl chloride resin in the fiber composite body 4 is melted even at a temperature lower than the melting point of the internal layer pipe 3, thus fusing the fiber composite body 4 and the internal layer pipe 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fiber-reinforced thermoplastic resin pipe that is suitably used under high temperature and pressure conditions, and a method for manufacturing the same.

[Conventional technology]

BACKGROUND ART Synthetic resin pipes have been widely used since they have superior properties such as being lighter and less rusty than metal pipes. However, this synthetic resin pipe is inferior to metal pipes in pressure resistance and impact resistance. Therefore,
In order to give these synthetic resin pipes pressure and impact resistance, a reinforcing layer made of fiber-reinforced thermoplastic resin is provided on the outer periphery of the inner pipe molded from thermoplastic resin, and this reinforcement layer is further reinforced with fibers. Fiber reinforcement in which the outer periphery of the layer is coated with a thermoplastic resin layer and a method for manufacturing the same have been proposed (see, for example, Japanese Patent Laid-Open No. 152786/1986). This fiber-reinforced manufacturing method involves heating the inner tube, which serves as the core material, to a temperature that melts the surface, and then winding and fusing strand-shaped reinforcing fibers impregnated with thermoplastic resin between filaments around the outer circumference of the inner tube. After forming a reinforcing layer by winding reinforcing fibers around the outer circumference of the inner tube, heating the inner tube to a temperature at which the surface melts and fusing it, etc., the outer circumference of this reinforcing layer is coated with thermoplastic resin. The material is extruded, coated, and heated.

[Problem to be solved by the invention]

However, in the conventional manufacturing method described above, in order to fuse the reinforcing fibers to the outer periphery of the inner layer pipe molded from thermoplastic resin,
It is necessary to heat the inner tube to a temperature at which the surface of the inner tube is fused. In that case, there is a problem in that the inner layer tube softened by heating is easily deformed by the tension of the reinforcing fibers wound around it, making it difficult to obtain a fiber-reinforced thermoplastic resin tube with high dimensional accuracy.

By the way, chlorinated vinyl chloride resin pipes have superior corrosion resistance compared to metal pipes, have considerable pressure resistance even at high temperatures of about 50 to 80°C, have excellent heat deformation resistance, are lightweight, Because it is easy to construct and inexpensive, it is widely used not only for water supply but also for hot water supply. Therefore, we thought that using chlorinated vinyl chloride resin as the material for the inner pipe and reinforcing the outer periphery with a reinforcing layer of glass fiber-reinforced thermosetting resin would be a shortcut to achieving the desired result.

The present invention has been made in view of the problems of the prior art described above, and its purpose is to achieve good fusion between the inner layer pipe made of chlorinated vinyl chloride resin and the fiber composite, and to achieve a fiber reinforcing effect. The object of the present invention is to provide a fiber-reinforced thermoplastic resin pipe with high dimensional accuracy, which has excellent properties and which does not cause deformation of the inner layer pipe.

[Means to solve the problem]

The method for producing a fiber-reinforced thermoplastic resin pipe of the present invention involves extruding a thermoplastic resin to form an inner layer tube, and forming a fiber composite in which the thermoplastic resin is held by reinforcing fibers made of a large number of filaments on the outer surface of the inner layer tube. In a method for manufacturing a fiber-reinforced thermoplastic resin pipe in which a body is wound or surrounded and fused, the inner layer pipe is molded using chlorinated vinyl chloride resin, and the thermoplastic resin constituting the fiber composite is It is characterized by using a chlorinated vinyl chloride resin that has a lower chlorine content than the chlorinated vinyl chloride resin that forms the inner layer pipe.

Generally, in order to obtain a high reinforcing effect with such fiber-reinforced pipes, it is necessary to improve the fusion bond between the inner layer pipe and the reinforcing layer. Alternatively, it is preferable to use a resin with good compatibility, and it is effective to provide a reinforcing layer using a thermoplastic resin for an inner layer tube made of a thermoplastic resin. Therefore, for inner pipes made of chlorinated vinyl chloride resin, the reinforcing layer is made of chlorinated vinyl chloride resin.

In the present invention, the chlorinated vinyl chloride resin pipe that becomes the inner layer pipe is made of chlorinated vinyl chloride resin with addition of heat stabilizers, lubricants, plasticizers, pigments, fillers, processing aids, modifiers, etc. according to the purpose. The m-acid compound is heated and kneaded using a screw extruder, and then passed through a mold to be molded. Note that the chlorinated vinyl chloride resin may be used alone or as a mixed resin with a resin having good compatibility with it (eg, vinyl chloride resin), depending on the purpose.

In the present invention, the fiber composite wound around the outer periphery of the inner tube is made by reinforcing fibers made of a large number of filaments impregnated with chlorinated vinyl chloride resin and held therein. If the thickness of the fiber composite is too thin, the reinforcing effect will not be sufficient.
If it is too thick, it will be difficult to wind it, so 0.1 to 2 mm.
A range of 5 to 50 plates is preferably used.

The reinforcing fibers used in the present invention include inorganic fibers such as glass fibers, carbon fibers, and metal fibers, and organic synthetic fibers such as aramid fibers and vinylon fibers, and have a diameter of 1 to 40 μm.
A string-like or tape-like material formed from a roving or yarn composed of tens to thousands of m filaments is generally used.

The chlorinated vinyl chloride resin impregnated into the filament has a lower chlorine content than the chlorinated vinyl chloride resin of the inner tube, and therefore has a lower softening temperature and melting temperature than the resin of the inner tube. Not done.

To make a fiber composite by impregnating reinforcing fiber filaments with chlorinated vinyl chloride resin, reinforcing fibers in the form of strands such as rovings or yarns made of filaments, ■ A fluidized bed of powdered chlorinated vinyl chloride resin. The resin is attached to the fibers by passing through it, ■ It is dried after passing through a liquid tank in which powdered chlorinated vinyl chloride resin is dispersed, ■ It is passed through a tank containing molten chlorinated vinyl chloride resin After drying, the fiber composite is made as it is, or the resin is once heated and melted.Furthermore, the resin attached to the fibers in the above step is heated and pressed by passing it through a heated roll, etc. to form a string. This can be done by forming it into a shape or a tape shape. Although it is possible to use it as it is, it is preferable to use the method (■) or (2) because the powdered resin is "muffed" by the fibers and easily falls off.

The content of reinforcing fibers in the fiber composite is preferably 5 to 80% by volume. If the amount of reinforcing fibers is less than 5% by volume, it is difficult to obtain a sufficient reinforcing effect, and if it exceeds 80% by volume, it becomes difficult to fuse with the interface of the inner layer pipe. Note that fusion as used herein refers to a state in which both resins are heated until they are in a molten state and are pressed together, and the two resins are not easily cut from the interface after cooling.

Furthermore, the manufacturing method of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing an example of a manufacturing apparatus for manufacturing the fiber-reinforced thermoplastic resin pipe of the present invention using the tape-shaped fiber composite formed as described in (2) above.

(2) is an extruder for melt-kneading and extruding chlorinated vinyl chloride resin. A mold 2 is attached to the tip of the extruder 1 to form the molten chlorinated vinyl chloride resin extruded from the extruder 1 into a hollow tubular inner tube 3. Two sets of winding devices 5, 5 rotate around the inner layer tube 3 and wind the tape-shaped fiber composite 4 around the outer circumference of the inner layer tube 3.
is provided. Two bobbin-shaped unwinding machines 5a, 5a for winding the fiber composite 4 are attached to each of the winding devices 5, 5, and are rotated around the inner layer tube 3 by a drive device (not shown). , each unwinding machine 5a, 5a
The tape-shaped fiber composite 4 is unwound from the inner tube 3 and wound helically around the outer periphery of the inner layer tube 3. Note that the two sets of winding devices 5, 5 are configured to rotate in mutually opposite directions. A hot air heating device 6.6 is provided near the front of each winding device 5, and is capable of heating the fiber composite 4 wound around the outer circumference of the inner tube 3. Further forward, there is an extruder equipped with a crosshead mold 8 for coating the outer periphery of a tubular body 11 in which the fiber composite 4 is wound in two layers around the outer periphery of the inner tube 3 with chlorinated vinyl chloride resin. 7, a cooling device 9 such as a water tank, and a collecting machine 10 are installed.

Next, a method for manufacturing the fiber-reinforced thermoplastic resin pipe of the present invention using the above-mentioned apparatus will be explained.

A chlorinated vinyl chloride resin to which a heat stabilizer, a lubricant, and other necessary additives have been added is melt-kneaded in an extruder 1 and passed through a mold 2 to form an inner pipe 3 by extrusion.

A tape-shaped fiber composite 4 is placed around the outer periphery of the inner tube 3 extruded from the mold 2 by an unwinding machine 5a of the first winding device 5.
, unrolled from 5a, wound in a helical shape so as to avoid gaps and overlaps, and sprayed hot air from around the fiber composite 4 using a hot air heating device 6 to dissolve the chlorinated vinyl chloride resin in the fiber composite 4. is heated and melted and fused to the inner layer tube 3 to form the first reinforcing layer. Subsequently, the second reinforcing layer is helically wound in the opposite direction to the second layer by the second winding device 5, and the tubular body 11 is formed in the same manner. In this way, by winding the first and second reinforcing layers in opposite directions, the fibers are less likely to shift even when stress is applied to the tube, compared to when they are wound in the same direction. , can exhibit excellent reinforcing effects.

As a method of winding and fusing the fiber composite around the inner layer pipe to form a reinforcing layer, winding it in the circumferential direction is simple and reasonable, but strength and dimensional accuracy in the pipe axis direction are required. In this case, the fiber composite may be fused while being surrounded along the tube axis direction.

In addition, when winding and fusing the fiber composite 4 around the outer circumference of the inner layer tube 3, in order to prevent the inner layer tube 3 from being deformed, the mold 2 must be
An extension core protruding in the extrusion direction is provided, and the fiber composite 4 is wound on this extension core, or cooling air is blown into the inner layer tube 3 from the tip of the mold 2, and the inner layer tube 3 is
Measures to prevent deformation may be taken, such as winding the fiber composite 4 while cooling the inner surface of the fiber composite.

Next, the tubular body 11 is passed through a crosshead mold 8 attached to an extruder 7, and the outer periphery of the tubular body 11 is coated with chlorinated vinyl chloride resin heated and kneaded by the extruder 7 to form an outer layer. Then, it is cooled by a cooling device 9 and taken by a taking machine 10 to obtain a fiber-reinforced thermoplastic resin pipe 12.

FIG. 2 is a schematic explanatory diagram showing another example of the manufacturing apparatus for manufacturing the fiber-reinforced thermoplastic resin pipe of the present invention. The manufacturing method of the fiber-reinforced thermoplastic resin pipe shown in Figure 1 above uses a tape-shaped fiber composite, but the manufacturing method shown in Figure 2 uses a strand-shaped fiber composite such as roving or yarn. It is used.

In FIG. 2, the same equipment as in FIG. 1 is given the same reference numerals and the explanation thereof will be omitted.

In FIG. 2, 14 is a roving-like fiber composite 13.
A plurality of bobbin-shaped unwinders 14a, 14a, . . . are installed on which the fiber composite 13 is wound. The fiber composite 13 is extruded from the inner layer tube 3 from the mold.
feed on top. 15 is a drum-shaped heating roll installed immediately after the unwinding device 14 for heating the fiber composite 13;
16 is a winding device for winding the fiber composite 13 around the inner layer tube 3 in the circumferential direction;
A plurality of bobbin-shaped unwinding machines 16a, 16 wound with
a ... are attached and rotate around the inner layer tube 3 by a drive device (not shown), and each unwinder 16
The fiber composite 13 is unwound from a, 16a, . . . and wound around the outer circumference of the inner layer tube 3.

A method for manufacturing the fiber-reinforced thermoplastic resin pipe of the present invention using the apparatus shown in FIG. 2 will be described.

A roving-like fiber composite 13 unwound from an unwinding device 14 is supplied to the circumferential tube axis direction of the inner layer tube 3 extruded in the same manner as in the case shown in FIG. The fiber composite 13 and the outer surface of the inner tube 3 are heated and fused together through the fiber composite 13 and the outer surface of the inner tube 3. Next, the fiber composite 13 is unwound from the winding device 16 and wound in the circumferential direction on the inner layer tube 3 reinforced in the tube axis direction. The body 13 is heated and melted to obtain a tubular body 17. Furthermore, an outer layer is formed around the outer periphery of the tubular body 17 in the same manner as in the case of FIG. 1 to obtain a fiber-reinforced thermoplastic resin tube 18.

The method for fusing the wound fiber composite to the inner layer pipe is as follows:
The fiber composite may be quickly wound and fused to the high-temperature inner layer tube immediately after being extruded from the mold, or -
First, the inner layer tube is cooled, and the outer surface and the fiber composite are heated simultaneously or separately with hot air, an infrared heater, etc. to the extent that the resin melts, and then the fiber composite is wound around the inner layer tube and fused. You can. When heating the inner layer tube, it is preferable to heat the inner layer tube rapidly in a short period of time so that only the outer surface thereof is melted and the inside of the tube wall is not melted.

Further, FIG. 1 shows an example in which there are two reinforcing layers in the circumferential direction of the fiber composite 4, and one outer layer of chlorinated vinyl chloride resin on top of that, and FIG. 2 shows an example in which the fiber composite 13 An example is shown in which there is one reinforcing layer in the tube axis direction, one reinforcing layer in the circumferential direction, and one outer layer of chlorinated vinyl chloride resin on top of that, but the number of each layer is particularly limited to these. It can be determined as appropriate depending on the application, required strength, etc.

In the above method for manufacturing a fiber-reinforced thermoplastic resin pipe,
We have described a method for producing fiber reinforced thermoplastic resin pipes in which filaments are impregnated with chlorinated vinyl chloride resin between the filaments on a separate line, and wound up on a bobbin-shaped unwinding machine to produce a fiber composite. A manufacturing method may be used in which the reinforcing layer is continuously wound or unwound around the inner tube while maintaining its shape, and is fused to form the reinforcing layer.

[Function] The inner layer tube is formed by extruding heated and melted chlorinated vinyl chloride resin from an extruder through a mold, and the fiber composite is unrolled from a winding device or an unwinding machine installed in an unwinding device. The inner layer tube and the fiber composite are heated and fused using a hot air heating device until the surface temperature of the inner layer tube is high enough to fuse the resin constituting the fiber composite. Chlorinated vinyl chloride resin has the property that the higher its chlorine content, and thus the degree of chlorination, the higher its heat distortion temperature and melting temperature. For this reason, by making the chlorine content of the chlorinated vinyl chloride resin impregnated into the fiber composite lower than the chlorine content of the chlorinated vinyl chloride resin constituting the inner layer pipe, it is possible to Even at a low surface temperature, the chlorinated vinyl chloride resin in the fiber composite melts, making it possible to firmly fuse the fiber composite and the inner pipe.

〔Example] Embodiments of the present invention will be described with reference to the drawings.

On Senshikaku (see Figure 1) In extruder 1, the chlorine content 6 is mixed with heat stabilizers, lubricants, etc.
After melting and kneading 8% by weight of chlorinated vinyl chloride resin and extruding an inner layer pipe 3 with an inner diameter of 23 mm and a wall thickness of about 3 mm using a mold 2 heated to a temperature of about 200"C, the outer surface temperature does not drop. While heating with the hot air heating device 6, the first layer fiber composite 4 is helically wound and fused using the winding device 5, and then in the same manner, the second N-th fiber composite 4 is formed. was helically wound in the opposite direction to the first layer and fused to form a tubular body 11.

The fiber composite 4 used had a thickness of about 0.5 mm and a width of about 20 m.
After opening a glass fiber roving, a chlorinated vinyl chloride resin having a chlorine content of 62% by weight was thoroughly impregnated between the fibers to form a tape shape of 500 m in diameter.

The amount of glass fiber in the fiber composite 4 was 30% by volume.

Next, the tubular body 11 is passed through a crosshead mold 8,
Chlorinated vinyl chloride resin melted and kneaded and extruded by an extruder 7 is coated on the outer periphery of the tubular body 11 to form an outer layer, cooled by a cooling device 9, taken out by a take-off machine 10, and cut into a predetermined length. A fiber-reinforced thermoplastic resin pipe 12 was obtained.

The fiber-reinforced thermoplastic resin tube 12 with the three-layer structure obtained as described above had good adhesion between the eyebrows, and there was almost no deformation of the inner surface of the tube.

Well Seventy-One (see Figure 2) Using chlorinated vinyl chloride resin with a chlorine content of 67% by weight,
After extruding an inner layer tube 3 of the same size using the same extruder and mold as in Example 1, the fiber composite 13 was unwound from the unwinding device t14 around the inner layer tube 3, and was preheated. The fiber composite 13 is placed in the tube axis direction, and is pressed and fused to the inner layer tube 3 with a drum-shaped heating roll 15. Then, while the tube surface is heated with a hot air heating device 6, the fiber composite 13 is wrapped around the outer circumference of the tube with a winding device 16. The tubular body 17 was obtained by winding and fusion-bonding the tubular body 17.

The fiber composite 15 used was in the form of a string with a diameter of about 0.5 mm, and after opening a glass fiber roving, a chlorinated vinyl chloride resin with a chlorine content of 64% by weight and a chlorinated vinyl chloride resin with a chlorine content of 57% by weight were placed between the fibers. % chlorinated vinyl chloride resin and molded. The amount of glass fiber in the fiber composite 15 was 25% by volume.

Next, in the same manner as in Example 1, the outer periphery of the tubular body 17 was coated with chlorinated vinyl chloride resin to form an outer layer, thereby obtaining a fiber-reinforced thermoplastic resin tube 18.

The fiber-reinforced thermoplastic resin pipe 19 with the three-layer structure obtained as described above had good adhesion between the layers, and there was almost no deformation on the inner surface of the pipe.

[Effects of the Invention] Since the present invention is configured as described above, the inner pipe made of chlorinated vinyl chloride resin and the fiber composite are well fused together, the fiber reinforcement effect is excellent, and the fibers have high dimensional accuracy. A reinforced thermoplastic tube can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an example of the fiber-reinforced thermoplastic resin pipe manufacturing apparatus of the present invention, and FIG. 2 is a schematic explanatory diagram showing another example of the fiber-reinforced thermoplastic resin pipe manufacturing apparatus of the present invention. be. 1.7... Extruder, 2... Mold, 3... Inner layer tube, 4,13... Fiber composite, 5.16.
... Winding device, 6... Hot air heating device, 8...
Crosshead mold, 9... Cooling device 10... Taking machine, 11.17... Tubular body, 12, 18... Fiber reinforced thermoplastic resin tube, 14... Unwinding device,
15... Heating roll.

Claims (1)

[Claims] (1) A thermoplastic resin is extruded to form an inner layer tube, and a fiber composite in which the thermoplastic resin is held by reinforcing fibers made of a large number of filaments is wound or surrounded and fused on the outer surface of the inner layer tube. In the method for manufacturing a fiber-reinforced thermoplastic resin pipe, the inner layer pipe is molded using a chlorinated vinyl chloride resin, and the thermoplastic resin constituting the fiber composite is made of a chlorinated vinyl chloride resin that forms the inner layer pipe. A method for producing a fiber-reinforced thermoplastic resin pipe, characterized in that a chlorinated vinyl chloride resin having a low chlorine content is used.