JPH074875B2 - Method for producing fiber reinforced thermoplastic resin pipe - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fiber-reinforced thermoplastic resin tube preferably used under high temperature and pressure and a method for producing the same.

[Prior Art] Synthetic resin pipes have been widely used since they have excellent properties such as light weight and no rust compared with metal pipes. However, this synthetic resin pipe is inferior in pressure resistance and impact resistance to a metal pipe. Therefore,
As a synthetic resin tube with pressure resistance and impact resistance, an inner layer tube molded from a thermoplastic resin is provided with a reinforced layer of a fiber reinforced thermoplastic resin on the outer periphery of the inner layer tube. Fiber reinforced by coating a thermoplastic resin layer on the outer periphery of the layer and a method for producing the same have been proposed (see, for example, JP-A-63-152786). In this fiber-reinforced manufacturing method, while heating the inner-layer tube to be the core material to a temperature at which the surface melts, the outer periphery of the inner-layer tube is wound and fused with a strand-like reinforcing fiber impregnated with a thermoplastic resin between filaments. Method, or after winding the reinforcing fiber around the outer circumference of the inner layer tube, by heating the inner layer tube to a temperature at which the surface melts and fusing the same, after providing a reinforcing layer, a thermoplastic resin on the outer circumference of this reinforcing layer Is extruded, coated and heated.

[Problems to be Solved by the Invention]

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

By the way, the chlorinated vinyl chloride resin pipe has excellent corrosion resistance as compared with metal pipes, has considerable pressure resistance even at a high temperature of about 50 to 80 ° C., and has excellent heat distortion resistance,
It is widely used not only for water supply but also for hot water supply because of its light weight, easy construction, and low cost. Therefore, it was considered to be a shortcut to obtain the desired product by using a chlorinated vinyl chloride resin as a material for the inner layer tube and reinforcing the outer periphery with a reinforcing layer of glass fiber reinforced thermosetting resin.

The present invention has been made in view of the above-mentioned problems of the prior art, and the purpose thereof is to achieve good fiber-reinforcing effect by fusing the inner layer pipe made of chlorinated vinyl chloride resin and the fiber composite. An object of the present invention is to provide a fiber-reinforced thermoplastic resin tube which is excellent and has high dimensional accuracy in which deformation of the inner layer tube does not occur.

[Means for Solving the Problems]

The method for producing a fiber-reinforced thermoplastic resin pipe of the present invention is a fiber composite in which a thermoplastic resin is extruded to form an inner layer pipe, and the outer surface of the inner layer pipe is provided with a reinforcing fiber made of a large number of filaments and the thermoplastic resin is retained therein. In a method for manufacturing a fiber-reinforced thermoplastic resin tube in which a body is wound or wrapped and fused, the inner layer tube is molded using a chlorinated vinyl chloride resin, and as the thermoplastic resin constituting the fiber composite, It is characterized by using a chlorinated vinyl chloride resin having a chlorine content lower than that of the chlorinated vinyl chloride resin forming the inner layer pipe.

In general, in order to obtain a high reinforcing effect with such a fiber-reinforced pipe, it is necessary to make good fusion between the inner layer pipe and the reinforcing layer, and therefore, whether the resins used for the inner layer and the reinforcing layer are the same. Alternatively, it is preferable to use a resin having good compatibility, and it is effective to dispose a reinforcing layer using a thermoplastic resin for the thermoplastic resin inner layer pipe. Therefore, for the inner layer pipe made of chlorinated vinyl chloride resin, the reinforcing layer is made of chlorinated vinyl chloride resin.

The chlorinated vinyl chloride resin pipe to be the inner layer pipe in the present invention is a chlorinated vinyl chloride resin, a heat stabilizer depending on the purpose,
A composition containing additives such as a lubricant, a plasticizer, a pigment, a filler, a processing aid, and a modifier is heated and kneaded by a screw type extruder and passed through a mold to be molded. The chlorinated vinyl chloride resin may be a single resin or a mixed resin with a resin having a good compatibility therewith (for example, vinyl chloride resin) depending on the purpose.

In the present invention, the fiber composite which is wound around the outer circumference of the inner layer tube is obtained by impregnating and holding a reinforcing fiber composed of a large number of filaments with a chlorinated vinyl chloride resin.
If the thickness of the fiber composite is too thin, the reinforcing effect is not sufficient, and if it is too thick, it becomes difficult to wind the fiber composite, so that the range of 0.1 to 2 mm and the width of 5 to 50 mm are preferably used.

Examples of the reinforcing fibers used in the present invention include inorganic fibers such as glass fibers, carbon fibers and metal fibers, organic synthetic fibers such as aramid fibers and vinylon fibers, and the like, having a diameter of 1 to 40 μm.
A string-like or tape-like one formed from rovings or yarns composed of tens to thousands of filaments is generally used.

The chlorinated vinyl chloride resin impregnated into the filament has a chlorine content lower than that of the chlorinated vinyl chloride resin of the inner layer tube, and is therefore particularly limited as long as it has a lower softening temperature and melting temperature than the resin of the inner layer tube. Not done.

To make a fiber composite by impregnating the filaments of reinforcing fibers with chlorinated vinyl chloride resin, the strand-like reinforcing fibers such as rovings or yarns made of filaments are placed in a fluidized bed of powdered chlorinated vinyl chloride resin. To attach the resin to the fiber, to pass through a tank of liquid in which powdered chlorinated vinyl chloride resin is dispersed, and then to dry, after to pass through a tank of molten chlorinated vinyl chloride resin It is dried to form a fiber composite as it is, or the resin is once heated and melted, and the resin adhered to the fiber is heated and pressed by a method such as passing through a heating roll to be formed into a string shape or a tape shape. , Etc. can be used. Although it is possible to use the resin as it is, it is preferable that the resin is in the state of being “sprinkled” with the powdery resin and easily falls off, or is manufactured by the method.

The content of the reinforcing fiber is preferably 5 to 80% by volume in the fiber composite. When the amount of the reinforcing fibers is less than 5% by volume, it is difficult to obtain a sufficient reinforcing effect, and when it exceeds 80% by volume, it becomes difficult to fuse the inner layer tube with the interface. Note that the fusion bonding here means a state in which both resins are heated and pressure-bonded until they are in a molten state, and are not easily cut from the interface after cooling.

Further, the manufacturing method of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic explanatory view showing an example of a production apparatus for producing the fiber-reinforced thermoplastic resin pipe of the present invention using the tape-shaped fiber composite formed as described above.

Reference numeral 1 is an extruder for melt-kneading a chlorinated vinyl chloride resin and extruding it. A die 2 for molding the molten chlorinated vinyl chloride resin extruded from the extruder 1 into a hollow tubular inner layer tube 3 is attached to the tip of the extruder 1, and the die 2 is extruded from the die 2 in front of the die 2. Two sets of winding devices 5, 5 are provided that rotate around the inner layer tube 3 and wind the tape-shaped fiber composite 4 around the inner layer tube 3. Two bobbin-shaped unwinders 5a, 5a wound with the fiber composite 4 are mounted on each of the winding devices 5, 5, respectively. The tape-shaped fiber composite 4 is unwound from each of the unwinders 5a, 5a and helically wound around the outer circumference of the inner layer tube 3. Two sets of winding device
5, 5 are configured to rotate in opposite directions. Hot air type heating devices 6, 6 are provided near the front of each winding device 5 to heat the fiber composite 4 wound around the outer circumference of the inner layer tube 3. Further ahead, the inner layer tube 3
Extruder 7, in which a crosshead mold 8 for coating a chlorinated vinyl chloride resin is attached to the outer periphery of a tubular body 11 in which the fiber composite 4 is wound in two layers on the outer periphery of a cooling device such as a water tank 9, the take-off machine 10 is installed.

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

A chlorinated vinyl chloride resin to which a heat stabilizer, a lubricant, and other necessary additives are added is melt-kneaded in an extruder 1 and passed through a mold 2 to extrude an inner layer tube 3.

On the outer periphery of the inner layer tube 3 extruded from the mold 2, the tape-shaped fiber composite 4 is unwound by the unwinders 5a, 5 of the first winding device 5.
It is unwound from a and helically wound so that no gaps and overlaps occur, and hot air is heated by the hot air heating device 6 from around the fiber composite 4 to remove the chlorinated vinyl chloride resin in the fiber composite 4. It is heated and melted, and fused with the inner layer pipe 3 to form a first reinforcing layer. Then, by the second unwinding device 5, the second reinforcing layer is helically wound in the opposite direction to the first layer, and the tubular body 11 is formed in the same manner. In this way, by winding the first layer and the second reinforcing layer in opposite directions, it is less likely that the fibers will be displaced even when stress is applied to the pipe, as compared with the case of winding in the same direction. , It is possible to exert an excellent reinforcing effect.

As a method of forming a reinforcing layer by winding and fusing the fiber composite on the inner layer tube, winding in the circumferential direction is simple and rational, but strength and dimensional accuracy in the tube axis direction are required. In that case, the fiber composite may be fused in a state of being surrounded along the tube axis direction.

In order to prevent the inner layer tube 3 from being deformed when the fiber composite 4 is wound around and fused to the outer circumference of the inner layer tube 3, the mold 2 is used.
Is provided with an extension core protruding in the extruding direction, and the fiber composite body 4 is wound on the extension core, or cooling air is blown into the inner layer tube 3 from the tip of the mold 2 to form the inner layer tube 3
You may take measures against deformation, such as winding the fiber composite 4 while cooling the inner surface of the.

Subsequently, the tubular body 11 is passed through a crosshead mold 8 attached to the extruder 7, and the outer periphery of the tubular body 11 is coated with a chlorinated vinyl chloride resin that has been heat-kneaded by the extruder 7 to form an outer layer. Then, the fiber reinforced thermoplastic resin tube 12 is obtained by cooling with the cooling device 9 and withdrawing with the take-up machine 10.

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

In FIG. 2, equipment common to FIG. 1 is given the same reference numeral, and description thereof will be omitted.

In FIG. 2, 14 is a winding device for supplying the roving-shaped fiber composite 13 in the axial direction of the peripheral tube of the inner layer tube 3, and a plurality of bobbin-shaped windings around which the fiber composite 13 is wound. Start
14a, 14a ... are attached, and the fiber composite 13
Are supplied onto the inner layer tube 3 extruded from the mold. 15 is installed immediately after the winding device 14 and has a drum-shaped heating roll for heating the fiber composite 13, and 16 is the inner wall of the fiber composite 13
It is a winding device that winds around the circumference of
Similarly, a plurality of bobbin-shaped unwinders 16a, 16a ... On which the fiber composite 13 is wound are attached, and the unwinding device rotates the periphery of the inner layer tube 3 to drive each unwinder 16a, 16a. The fiber composite 13 is unwound from 16a ... and wound around 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.

The roving-shaped fiber composite 13 unwound from the winding device 14 is fed in the axial direction of the peripheral tube of the inner layer tube 3 extruded in the same manner as in the case of FIG. The fiber composite body 13 and the interface between the inner layer tube 3 are heated and fused through. Next, unwind the fiber composite 13 from the winding device 16,
The fiber composite body 13 is wound in the circumferential direction on the inner layer tube 3 reinforced in the tube axis direction, and the fiber composite body 13 is heated and melted by the hot air type heating device 6 to obtain the tubular body 17. Further, as in the case of FIG. 1, an outer layer is formed on the outer periphery of the tubular body 17 to obtain the fiber-reinforced thermoplastic resin tube 18.

As a method of fusing the wound fiber composite to the inner layer tube,
The fiber composite may be quickly wound and fused on the hot inner layer tube immediately after being extruded from the mold, or the inner layer tube may be cooled once and its outer surface and the fiber composite may be simultaneously or separately separated. Alternatively, the fiber composite may be wound and fused around the inner layer tube after being heated with hot air or an infrared heater to such an extent that the resin is melted. The heating of the inner layer pipe is preferably carried out rapidly in a short time so that only the outer surface of the inner layer pipe is melted and the inside of the pipe meat is not melted.

Further, FIG. 1 shows an example in which two reinforcing layers in the circumferential direction by the fiber composite 4 are provided, and one outer layer of chlorinated vinyl chloride resin is further provided thereon, and FIG. 2 shows the fiber composite 13 An example in which there is one reinforcing layer in the pipe axis direction, one reinforcing layer in the circumferential direction, and one outer layer of chlorinated vinyl chloride resin on the
The number of each layer is not particularly limited to these, applications,
It can be appropriately determined according to the required strength and the like.

In the method for producing the fiber-reinforced thermoplastic resin pipe,
A method for producing a fiber-reinforced thermoplastic resin tube in which a chlorinated vinyl chloride resin is impregnated between filaments on a separate line and wound on a bobbin-shaped unwinder to produce a fiber composite has been described. It may be a manufacturing method in which the reinforcing layer is formed by continuously winding or unwinding around the inner layer tube while forming the body and fusing.

[Action]

An inner layer tube is formed by extruding heat-melted chlorinated vinyl chloride resin from an extruder through a mold, and the fiber composite is unwound from the unwinder installed in the winding device or unwinding device. The body is wound or surrounded, and the inner layer tube and the fiber composite body are heated and fused by a hot air heating device to such an extent that the surface temperature of the inner layer tube can fuse the resin constituting the fiber composite body. The chlorinated vinyl chloride resin has the property that the higher the chlorine content, and thus the higher the degree of chlorination, the higher the heat distortion temperature and the melting temperature. Therefore, by lowering the chlorine content of the chlorinated vinyl chloride resin impregnated in the fiber composite to be lower than the chlorine content of the chlorinated vinyl chloride resin that constitutes the inner layer tube, the melting point or heat distortion temperature of the inner layer tube Even at a low surface temperature, the chlorinated vinyl chloride resin in the fiber composite can be melted, and the fiber composite and the inner layer tube can be firmly fused.

〔Example〕

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

Example 1 (see FIG. 1) In the extruder 1, a chlorine content of 68 including a heat stabilizer, a lubricant, etc.
Melt and knead wt% chlorinated vinyl chloride resin and keep the temperature about 20
After the inner layer tube 3 having an inner diameter of 23 mm and a wall thickness of about 3 mm is extrusion-molded by the mold 2 heated to 0 ° C., the inner surface of the inner layer tube 3 is extruded and then heated by the hot air heating device 6 so that the outer surface temperature does not decrease. The first layer of fiber composite 4 is helically wound and fused,
Next, in the same manner, the fiber composite body 4 of the second layer is helically wound in the direction opposite to the direction of the first layer and fused to form a tubular body 11.
And

The fiber composite 4 used is a tape having a thickness of about 0.5 mm and a width of about 20 mm, and after the roving of the glass fiber is opened, it is well impregnated with a chlorinated vinyl chloride resin having a chlorine content of 62% by weight. And molded. The amount of glass fiber in the fiber composite 4 is 30
It was% by volume.

Then, the tubular body 11 is passed through the crosshead mold 8, and the outer periphery of the tubular body 11 is formed by coating the outer periphery of the tubular body 11 with the chlorinated vinyl chloride resin melt-kneaded and extruded by the extruder 7 and cooled by the cooling device 9. Then, the fiber reinforced thermoplastic resin tube 12 was obtained by picking it up with a take-up machine 10 and cutting it into a predetermined length.

The fiber-reinforced thermoplastic resin tube 12 having a three-layer structure obtained as described above had good adhesion between the layers, and the inner surface of the tube was hardly deformed.

Example 2 (see FIG. 2) Using a chlorinated vinyl chloride resin having a chlorine content of 67% by weight, using the same extruder and mold as in Example 1, using the same size inner layer tube 3
After extrusion molding, the fiber composite body 13 is unwound around the inner layer tube 3 from the winding device 14, preheated and arranged in the tube axis direction, and extruded and fused to the inner layer tube 3 with a drum-shaped heating roll 15. Then, while the tube surface is heated by the hot air type heating device 6, the winding device 16
Thus, the fiber composite body 13 was wound around the outer circumference of the tube and fused to form a tubular body 17.

The fiber composite 15 used is a cord having a diameter of about 0.5 mm, and after the roving of glass fiber is opened, a chlorinated vinyl chloride resin having a chlorine content of 64% by weight and a chlorine content of 57% by weight are provided between the fibers. Was well impregnated with a 10: 1 mixture of chlorinated vinyl chloride resin of 1. The glass fiber amount in the fiber composite 15 was 25% by volume.

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

The fiber-reinforced thermoplastic resin tube 19 having a three-layer structure obtained as described above had good adhesion between the layers, and the tube inner surface was hardly deformed.

〔The invention's effect〕

Since the present invention is configured as described above, the inner layer pipe made of chlorinated vinyl chloride resin and the fiber composite are well fused, the fiber reinforcing effect is excellent, and the fiber reinforced thermoplastic resin pipe having high dimensional accuracy is high. Can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an example of an apparatus for manufacturing a fiber reinforced thermoplastic resin pipe of the present invention, and FIG. 2 is a schematic explanatory view showing another example of an apparatus for manufacturing a fiber reinforced thermoplastic resin tube of the present invention. is there. 1, 7 ... Extruder, 2 ... Mold, 3 ... Inner layer tube, 4, 13 ... Fiber composite, 5, 16 ... Winding device, 6 ... Hot air type heating device, 8 ... Crosshead mold, 9 ... Cooling Equipment, 10 ... Take-up machine, 11, 17 ... Tubular body, 12, 18 ... Fiber reinforced thermoplastic resin tube, 14 ... Unwinding device, 1
5 ... Heating roll.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location // B29C 53/58 7421-4F B32B 1/08 A 7158-4F B29K 27:06 B29L 23:22

Claims (1)

[Claims] 1. An inner layer tube is molded by extruding a thermoplastic resin,
In the method for producing a fiber-reinforced thermoplastic resin tube in which a fiber composite, in which a thermoplastic resin is held by reinforcing fibers composed of a large number of filaments, is wound or surrounded and fused on the outer surface of the inner layer tube, the inner layer tube is Molding using a chlorinated vinyl chloride resin, as the thermoplastic resin constituting the fiber composite, to use a chlorinated vinyl chloride resin having a lower chlorine content than the chlorinated vinyl chloride resin forming the inner layer tube A method for producing a fiber-reinforced thermoplastic resin tube, which is characterized.