JPH0911354A - Manufacture of fiber reinforced thermoplastic resin composite tube - Google Patents

Abstract

PURPOSE: To provide a manufacturing method for a fiber reinforced thermoplastic resin composite tube in which bonding force on interfaces is kept strong without lowering productivity and no interface releases nor cracks are generated even when used under the severe conditions or used for a long time. CONSTITUTION: A manufacturing method comprises the processes of forming a multilayer tubular body of two layers or more by laminating a fiber reinforced thermoplastic resin layer B composed of fiber reinforced resin belts on the outer peripheral face of a thermoplastic resin tube A, and then guiding the multilayer tubular body into a heating oven, and exposing the multilayer tubular body under the condition of either heating the inner side atmosphere of the multilayer tubular body or reducing the pressure of the outer side atmosphere, or under the condition of both atmospheres and heating and fusion bonding and integrating the thermoplastic resin tube A with the fiber reinforced thermoplastic resin layer B. As for the fiber reinforced thermoplastic layer resin belts, the belts with a number of through-holes are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a fiber-reinforced thermoplastic resin composite tube having a thermoplastic resin tube as an inner layer and a fiber-reinforced thermoplastic resin layer laminated on the outer peripheral surface thereof to form a multilayer of two or more layers. It is about the method.

[0002]

2. Description of the Related Art A fiber-reinforced resin composite pipe having a layer made of a thermoplastic resin on its inner surface is
It is not rusted and has excellent strength, and is widely used as pipes for transporting fluids such as water and gas, pipes used for electric wiring, structural members and the like.

Conventionally, in a fiber-reinforced composite pipe, a reinforcing fiber impregnated with a liquid thermosetting resin is wound around a mandrel on the outer surface of a thermoplastic resin pipe as an inner layer, and the mandrel is cured after the thermosetting resin is cured. It is manufactured by a drawing method (filament winding method) (for example, see Japanese Patent Publication No. 62-773).

This type of fiber-reinforced resin composite pipe has a weak adhesive force at the interface, and when the fiber-reinforced resin composite pipe is used under conditions of repeated heat and cold, due to the difference in linear expansion coefficient between the inner layer and the fiber-reinforced resin layer, There is a problem of causing interfacial peeling.

To solve this problem, for example, in Japanese Unexamined Patent Publication No. 6-218841, a reinforcing layer made of a fiber-reinforced resin composite is wound and laminated on the outer surface of a pipe made of a thermoplastic resin as an inner layer. To form a multilayer tubular body, when fusing the multilayer tubular body, either pressurize the inner atmosphere of the multilayer tubular body or depressurize the outer atmosphere, or both, and heat the multilayer tubular body by exposing it to the atmosphere, A method has been proposed in which a tube made of a thermoplastic resin and a fiber-reinforced resin composite are firmly fused and integrated.

[0006]

However, in the case of this method, when the multilayer tubular body is heat-sealed, the laminating pressure at the time of laminating each layer of the multilayer tubular body is considerably improved, and the thermoplastic resin pipe is The air entrainment at the interface between the fiber and the fiber-reinforced thermoplastic resin layer and the interface between the reinforcing fibers is significantly improved, but the fiber reinforcement does not cause interfacial peeling or cracking even under severe conditions or long-term use. In order to obtain a thermoplastic resin composite pipe, it is necessary to lengthen the heating furnace or reduce the production rate.If the heating furnace is lengthened, the production line will become longer, the capital investment will increase, and the production will increase. However, there is a problem in that

The present invention solves the above-mentioned conventional problems, has a strong adhesive force at the interface without lowering the productivity, and can be used even under severe conditions or for a long period of time. The object of the present invention is to provide a method for producing a fiber-reinforced thermoplastic resin composite pipe without peeling or cracking.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a fiber reinforced thermoplastic resin layer made of a fiber reinforced thermoplastic resin strip is laminated on the outer peripheral surface of a thermoplastic resin tube to form a multilayer tubular body having two or more layers. After that, the multi-layer tubular body is introduced into a heating furnace, and the multi-layer tubular body is heated by exposing it to the inner atmosphere of the multi-layer tubular body, the depressurization of the outer atmosphere, or both. A method for producing a fiber-reinforced thermoplastic resin composite tube including a step of fusion-bonding a plastic resin tube and a fiber-reinforced thermoplastic resin layer, wherein a plurality of through-holes are provided as a fiber-reinforced thermoplastic layer resin strip. A method for producing a fiber-reinforced thermoplastic resin composite pipe using the provided one.

In the present invention, as the thermoplastic resin constituting the thermoplastic resin tube, one suitable for the purpose of use of the obtained composite tube may be appropriately selected. For example, polyvinyl chloride, chlorinated polyvinyl chloride. , Polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, polyether ether ketone, and the like. These thermoplastic resins may be used alone or in combination of two or more.

If necessary, a heat stabilizer, a plasticizer, a lubricant, an antioxidant, a colorant, an ultraviolet absorber, a processing aid, an inorganic filler and the like are appropriately added to the thermoplastic resin.

In the present invention, the thermoplastic resin as the matrix resin forming the fiber-reinforced thermoplastic resin strip (hereinafter referred to as the strip) is the same as the thermoplastic resin forming the thermoplastic resin tube. Can be used.
These thermoplastic resins are usually used alone,
You may use together multiple types. 2 fiber reinforced thermoplastic resin layers
In the case of more than one layer, the matric resins in each layer do not necessarily have to be the same kind of thermoplastic resin, but it is necessary to select heat materials having excellent mutual compatibility.

Examples of the reinforcing fibers constituting the belt-like body are inorganic fibers such as glass fibers and carbon fibers, metal fibers such as stainless fibers and copper fibers, aramid fibers, vinylon fibers, rayon fibers, polyester fibers and hemp fibers. Continuous fibers such as rovings or strands made of continuous filaments having a diameter of 1 to several tens of μm are used.

If the amount of the fibers in the strip is too large, the amount of the thermoplastic resin held between the fibers will be small, and if it is too small, the reinforcing effect will not occur, so 3 to 70% by weight is preferable, and 10 to 50% by weight. Weight% is more preferred.

As the band-shaped body, one having a large number of through holes is used. As a method of manufacturing the band-shaped body, a plurality of needle-shaped protrusions are provided radially on the cooling roll in view of continuous manufacturing. A method in which the strip is passed over the obtained product is preferable. The interval of the protrusions at this time can be appropriately selected and determined, but is, for example, 5 to 50 mm.

When the specific heat of the projection is small, the through hole can be provided without solidifying the thermoplastic resin in a molten state, but when the specific heat is high, the thermoplastic resin comes into contact with the projection. It is preferable to form the through holes while heating the protrusions, because they sometimes solidify and the reinforcing fibers cannot be moved.

The cross-sectional shape of the protrusions is circular in terms of easiness of opening the through holes and easiness of pushing the reinforcing fibers.
Examples include an oval shape and a diamond shape. The length of the protrusion is appropriately determined in consideration of the wall thickness of the strip to be manufactured, the strength of the protrusion, the diameter of the cooling roll on which the protrusion is provided, and the like.

The size of the through hole has a diameter of 0.3 to 2 mm.
Is preferable, and 0.5-1.5 mm is more preferable. If the diameter is too small, it will be difficult to sufficiently remove bubbles, and the fusion strength at the interface will be adversely affected. If the diameter is too large, the strength of the strip will be insufficient, leading to a decrease in the strength of the resulting composite pipe.

The fiber-reinforced thermoplastic resin layer, which is laminated by winding a strip around the outer surface of the thermoplastic resin tube, has a first reinforcing layer in which the reinforcing fibers are arranged in the axial direction and a reinforcing fiber in a substantially circumferential direction. When a fiber-reinforced thermoplastic resin composite pipe provided with two or more layers composed of a combination of second reinforcement layers arranged in the axial direction is used, the first reinforcement layer suppresses the linear expansion coefficient in the axial direction of the pipe, and heat Expansion and contraction are reduced, and the pressure resistance of the second reinforcing layer is improved, which is preferable.

As the band-shaped body for forming the first reinforcing layer, there is used one in which a thermoplastic resin is impregnated between filaments of continuous fibers and formed into a sheet by heating and pressurizing. In this sheet-shaped strip, continuous fibers are arranged substantially parallel to the longitudinal direction. The width of the sheet-shaped strip is slightly longer than the perimeter of the fiber-reinforced thermoplastic resin layer, and the thickness is determined by the desired thickness of the first reinforcing layer.

As the band-shaped body for forming the second reinforcing layer, a tape-shaped or string-shaped body in which a filament of continuous fiber is impregnated with a thermoplastic resin and which is heated and pressed to be used. In this tape-shaped or string-shaped strip, continuous fibers are arranged substantially parallel to the longitudinal direction. The width and thickness of the tape or string are not particularly limited, but for example, in the case of a tape-shaped band, the thickness is preferably about 0.1 to 10 mm,
It is more preferably about 0.1 to 3 mm, and in the case of a string-shaped strip, one having a diameter of 0.5 to 5 mm is preferably used.

Examples of the method for producing the band-shaped body include the following methods. A roving-like or strand-like continuous fiber composed of a large number of filaments is sequentially passed through a fluidized bed of powdery thermoplastic resin to adhere the powdery thermoplastic resin between the fibers, and then once dried if necessary. After that, the continuous fiber and the thermoplastic resin are integrated into a desired shape such as a sheet shape, a tape shape, and a string shape by heating and pressing. In the case of a resin having a low melt viscosity, the same method as that for impregnating the continuous fiber by immersing the continuous fiber in a bath of the molten resin.

The pressure applied to the inner atmosphere of the multi-layered tubular body cannot be generally determined because it depends on the dimensions of the resulting composite tube, but it is preferably in the range of 0.01 to 10 kg / cm ² . Specifically, inner diameter 25 mm, wall thickness 3.5 mm
In this case, the applied pressure is preferably 0.01 to 3 kg / cm ² . When pressure is less than 0.01 kg / cm ^2, not obtained sufficient lamination pressure, it is necessary to note that in some cases 3 kg / cm ² and can not be obtained contour of accuracy blistering tube exceeds .

On the other hand, the decompression force of the side atmosphere of the multilayer tubular body is
Similarly, although it cannot be generally stated, 500 mmHg or more is usually preferable. When the decompression force is less than 500 mmHg, the multilayer tubular body cannot be provided with sufficient stacking pressure and deaeration effect. Further, when both the pressurized and depressurized atmospheres are used, a composite pipe having an excellent fusion bonding property between the thermoplastic resin pipe and the fiber-reinforced thermoplastic resin layer can be obtained.

The heating temperature of the heating furnace is preferably from the Vicat softening temperature to the thermal decomposition temperature of the matrix resin of the multilayer tubular body, and more preferably around the molding temperature in the extrusion, injection molding and the like of the above resin. When the heating temperature is lower than the Vicat softening temperature of the above resin, 0.01 to 10 kg / c
Pressurizing force in the range of m ² and 500 mmH outside the multilayer tubular body
Even if the thermoplastic resin tube of the multilayer tubular body and the fiber-reinforced thermoplastic resin layer are not heat-sealed even when heated under a reduced pressure such that the decompression force is g or more, the performance of the obtained tube is higher than the thermal decomposition temperature. Becomes worse.

The Vicat softening point is JIS K 7
The value measured according to 206. The Vicat softening temperature of a thermoplastic resin is, for example, about 65 for polyvinyl chloride.
~ 85 ° C, about 95-120 ° C for chlorinated polyvinyl chloride
It is. The term "heat fusion" means that both thermoplastic resins are heated to a molten state and then pressure-bonded, and after cooling, the fused interfaces do not easily break.

In the present invention, it is more preferable that an outer layer made of a thermoplastic resin is further provided on the outer peripheral surface of the multilayer tubular body in order to protect the outer surface and improve the appearance. The thermoplastic resin for forming the outer layer is not particularly limited, but a resin having a good heat fusion property to the matrix resin of the multilayer tubular body is preferably used.

An example of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing an example of a band-shaped body used in the present invention. Reference numeral 1 denotes a sheet-shaped (or tape-shaped) strip made of a fiber-reinforced thermoplastic resin, in which the thermoplastic resin 2 is used as a matrix resin, in which the reinforcing fibers 3 are arranged along the longitudinal direction, A large number of through holes 4 are provided at predetermined intervals. The reinforcing fibers 3 around the through-hole 4 are bent so as to be pushed away when punched by the protrusion.

FIG. 2 is a front view for explaining an example of the manufacturing process of the strip-shaped body used in the present invention together with the manufacturing apparatus.
First, the manufacturing apparatus will be described. The manufacturing apparatus has a plurality of reinforcing fiber rewinding rolls 29, a fluidized bed device 28 arranged above and below, a guide bar 30, and two pairs of heating rolls 32, 33 in order from the upstream side to the downstream side. And a cooling roll 35 in which a large number of needle-like protrusions 34 are radially provided.
A guide roll 36 and a winding roll 37 are arranged. The fluidized bed apparatus 28 is filled with the thermoplastic resin powder R.

Next, an example of a process of manufacturing a belt-shaped body using this manufacturing apparatus will be described. Multiple reinforcing fiber rewind rolls 2
9, the reinforcing fibers F1 and F1 are unwound by a rewinding roll 37 so as not to be twisted, and each is guided by a guide roll 30 to pass through the inside of the upper and lower fluidized bed devices 28, 28, thereby floating therein. A thermoplastic resin-impregnated reinforced fiber bundle F2, F2 in which the powdery thermoplastic resin R filled in the state is impregnated between filament fibers is produced.

This thermoplastic resin-impregnated reinforced fiber bundle F2, F
Two pairs of heating rolls 32, 3 so that 2 are overlapped
A strip F3 is produced by passing between three. Subsequently, the strip F3 is applied to a cooling roll 35 provided with a large number of needle-like protrusions 34 radially, so that a large number of through holes corresponding to the plurality of needle-like protrusions 34 are formed in the strip F3. Perforate, pass through a turn roll 31,
Take up on a take-up roll 37.

FIG. 3 is a front view showing an example of a process for manufacturing the composite pipe of the present invention together with a manufacturing apparatus. First, the manufacturing apparatus will be described. The manufacturing apparatus includes, in order from the upstream side to the downstream side, a rewinding roll 41 of the sheet-shaped strip 40, a first cross head die 43 to which the first extruder 42 is connected, and a first cross. Cooling die 45 mounted on the tip of head die 43 and tape-shaped strip 15
The winding device 14, the heating furnace 18, the second crosshead die 18 to which the second extruder 47 is connected, the sizing device 49, and the take-up device 19 are arranged.

The first crosshead die 43 includes an inner core 44 having bulged portions 441 and 441 in two stages, and the sheet-shaped strip 40 is formed into a cylindrical shape to form a first reinforcing layer. In addition, a thermoplastic resin pipe for the inner layer can be molded on the inner surface thereof.

A support 12 made of wire is extended from the inner core 44 to the front of the take-up machine 19, and a seal plate 13 for sealing the inside of the multilayer tubular body is attached to the tip of the support 12. A through hole is provided in the inner core 44, and the compressor 16 can pressurize the inner atmosphere of the multilayer tubular body through the gas flow path 17 and the through hole.

In the heating furnace 18, the multilayer tubular body passing through the heating furnace 18 is heated by a heating device (not shown), and the atmosphere outside the multilayer tubular body can be depressurized by the suction device 10. .

An example of the method for producing the fiber-reinforced thermoplastic resin composite pipe of the present invention will be described below. The sheet-shaped strip 40 is set on the rewinding roll 41, and the tape-shaped strip 15 is set on the winding device 14.

First, in the first crosshead die 43,
The unwinding roll 41 guides the sheet-like strip 40 while unwinding it to form a cylindrical shape to form a first reinforcing layer B1 in which reinforcing fibers are arranged in the axial direction, and at the same time, the first extruder 4
The thermoplastic resin for the inner layer kneaded in 2 is supplied to the first
The thermoplastic resin pipe A for the inner layer is laminated in the reinforced layer B, and is cooled by the cooling mold 45 to form a two-layer tubular body.

The winding device 14 is provided on the outer peripheral surface of the two-layer tubular body.
The tape-shaped strip 15 is wound by being heated by the hot air generator 46 by means of which the reinforcing fibers are arranged in the circumferential direction.
The reinforcing layer B2 is laminated to form a three-layer tubular body in which the fiber-reinforced thermoplastic resin layer B including the first reinforcing layer B1 and the second reinforcing layer B2 is laminated on the outer peripheral surface of the thermoplastic resin tube A. .

The three-layer tubular body is introduced into the heating furnace 18, the outside atmosphere of the three-layer tubular body is depressurized by the suction device 10, and the inside atmosphere of the three-layer tubular body is pressurized by the compressor 16. Heat while doing. As a result, an expansion pressure acts on the three-layer tubular body, and the thermoplastic resin of each layer is brought into close contact in a molten state. It should be noted that either the pressurization of the inner atmosphere or the depressurization of the outer atmosphere of the three-layer tubular body may be used.

Next, in the second crosshead die 48,
While guiding the three-layer tubular body, a thermoplastic resin for the outer layer is supplied in a molten state by the second extruder to form a four-layer tubular body in which the outer layer C is laminated on the outer peripheral surface of the three-layer tubular body. When this is cooled by passing it through the sizing device 49, the interfaces between the layers are fused. These series of operations are carried out while being taken by the take-up device 19, and cut by a not-shown cutting device to obtain the fiber-reinforced thermoplastic resin composite pipe 51 as shown in FIG.

[0040]

According to the method for producing a fiber-reinforced thermoplastic resin composite pipe of the present invention, a fiber-reinforced thermoplastic resin layer composed of a fiber-reinforced thermoplastic resin strip is laminated on the outer peripheral surface of the thermoplastic resin pipe.
After forming a multi-layered tubular body having more than one layer, the multi-layered tubular body is introduced into a heating furnace and pressurized under the inner atmosphere of the multi-layered tubular body or under reduced pressure of the outer atmosphere, or under the multi-layered tubular body under both atmosphere conditions. By exposing and heating the body, an expansion pressure can be applied to the multilayer tubular body, but at this time,
By using a fiber-reinforced thermoplastic layer resin strip provided with a large number of through holes, it is possible to reliably expel the air bubbles entrained in the interface in a short time, so that the interface can be adhered. The heat fusion of the interface can be performed more reliably.

[0041]

The present invention will be described below with reference to examples. Example (1) Manufacture of band-shaped body A band-shaped body as shown in FIG. 1 was manufactured by the manufacturing process described with reference to FIG. As the thermoplastic resin powder R, powdered chlorinated polyvinyl chloride (chlorination degree: 67%, polymerization degree:
1000) 100 parts by weight of a chlorinated polyvinyl chloride composition containing 4 parts by weight of a tin stabilizer, 2 parts by weight of stearyl alcohol, and 0.5 parts by weight of polyethylene wax was used. In the fluidized bed device 28 arranged above and below,
The thermoplastic resin powder R was filled.

The cooling roll 35 has a diameter of 225 mm.
A plurality of conical needle-like projections 34 having a diameter of 1 mm and a height of 10 mm, which are radially provided so that the circumferential angle is 45 ° and the axial distance is 10 mm. Was used.

Roving glass fiber bundle (4,400 tex) F composed of filaments having a diameter of 23 μm
While rewinding 1, F1, upper and lower fluidized bed devices 28, 28
A thermoplastic resin-impregnated reinforced fiber bundle F in which a thermoplastic resin R is impregnated between filament fibers by passing through the inside.
2, F2 was prepared, and the surface temperature was set to 200 ° C. 2
It passes through a pair of heating rolls 32, 32 and passes through a cooling roll 35 provided with a large number of needle-shaped projections 34,
A sheet-shaped strip (thickness: 0.8 mm, width: 1) having a large number of through holes with a diameter of 0.9 mm corresponding to the needle-shaped protrusions 34.
70 mm) and a tape-shaped strip (thickness: about 0.5 mm,
Width: about 20 mm). The fiber content of each of them was 25% by weight.

(2) Production of Fiber Reinforced Thermoplastic Resin Composite Pipe According to the production process described with reference to FIG. 3, the fiber reinforced thermoplastic resin composite pipe as shown in FIG. 4 was produced. The rewind roll 41 was fitted with a sheet-shaped strip, and the winding device 14 was fitted with a tape-shaped strip.

The sheet-shaped strip 40 is guided into the first crosshead die 43 to have an outer diameter of 56.6 mm and a wall thickness of 0.8 m.
The same chlorinated polyvinyl chloride resin composition used as the thermoplastic resin powder R in the first extruder 42 while forming the first reinforcing layer B by shaping it into a cylindrical shape of m The thermoplastic resin for the inner layer is kneaded and supplied, the thermoplastic resin pipe A for the inner layer is laminated in the first reinforcing layer B1, and this is cooled by the cooling die 45 to have an outer diameter of 56. A two-layer tubular body having a thickness of 6 mm and a wall thickness of 2.8 mm was formed.

The winding device 14 is provided on the outer peripheral surface of the two-layer tubular body.
The tape-shaped strip 15 was heated by the hot air generator 46 while being spirally wound at an angle of 75 ° with respect to the axial direction, and the second reinforcing layer B2 was laminated to form a three-layer tubular body.

This three-layer tubular body is introduced into a reduced-pressure heating furnace 18 kept at 300 ° C., the outside atmosphere of the three-layer tubular body is maintained at a reduced pressure of 550 mmHg by a suction device 10, and the three-layer tubular body is compressed by a compressor 16. The atmosphere inside the body was pressurized at a pressure of 0.4 Kg / cm ² , and an expansion pressure was applied to the three-layer tubular body to bring the thermoplastic resins of the respective layers into close contact in a fused state.

Next, this three-layer tubular body was introduced into the second crosshead die 48, and the same chlorinated polyvinyl chloride resin used as the thermoplastic resin powder R in the second extruder 47 was used. By kneading and supplying the thermoplastic resin for the outer layer comprising the composition to form a four-layer tubular body in which the outer layer C is laminated on the outer peripheral surface of the three-layer tubular body, and passing this through the sizing device 49. After cooling, the interfaces between the layers are fused, and a series of these operations is carried out while being taken by the take-up device 19, and cut by a cutting machine to obtain an outer diameter 60 as shown in FIG.
A fiber-reinforced thermoplastic resin tube having a diameter of 51 mm, an inner diameter of 51 mm, and a wall thickness of 4.5 mm was obtained.

(3) Cold and hot water flow through the fiber reinforced thermoplastic resin pipe
Repeated test Ten pieces of the fiber-reinforced thermoplastic resin tube obtained by cutting to 500 mm were connected. 5 tubes of hot water at 95 ° C
A cold and hot water repetitive test was conducted in which the operation of passing water for 25 minutes and then passing cold water at 25 ° C. for 5 minutes was repeated 10,000 cycles. After the test was completed, the number of samples, that is, the surface state of 20 end faces was observed. As a result, no abnormality such as delamination or cracking between the layers was observed.

Comparative Example A fiber-reinforced thermoplastic resin tube similar to that of the example was obtained in the same manner as in the example except that a sheet-like strip and a tape-like strip having no through holes were used. With respect to the obtained fiber reinforced thermoplastic resin pipe, a cold water flow test was conducted in the same manner as in the example. At the end of 5,000 cycles, the first reinforcing layer B was formed on each of two end faces of the 20 end faces. A crack of about 5 mm is generated at the interface of the second reinforcing layer C, and at the end of 10,000 cycles, 5 to 5 interfaces are formed at the interface between the first reinforcing layer B and the second reinforcing layer C, respectively.
It was observed that a 10 mm crack had occurred.

[0051]

EFFECTS OF THE INVENTION The method for producing a fiber-reinforced thermoplastic resin composite pipe of the present invention is configured as described above, and therefore the adhesive strength at the interface is strong and the harsh conditions are maintained without lowering the productivity. It is possible to obtain a fiber-reinforced thermoplastic resin composite pipe that does not cause interfacial peeling or cracking even when used below or for a long time.

[Brief description of the drawings]

FIG. 1 is a partially cutaway enlarged perspective view showing an example of a band-shaped body used in the present invention.

FIG. 2 is a front view illustrating an example of a manufacturing process of the strip-shaped body used in the present invention together with a manufacturing apparatus.

FIG. 3 is a front view for explaining an example of a manufacturing process of the fiber-reinforced thermoplastic resin composite pipe according to the present invention together with a manufacturing apparatus.

FIG. 4 is a partially cutaway perspective view showing an example of a fiber-reinforced thermoplastic resin composite pipe obtained by the present invention.

[Explanation of symbols]

 A thermoplastic resin tube B fiber reinforced thermoplastic resin layer 4 through hole 15,40 strip 18 heating furnace

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Claims (1)

[Claims] 1. A multilayer tubular body is formed by laminating a fiber-reinforced thermoplastic resin layer made of a fiber-reinforced thermoplastic resin strip on the outer peripheral surface of a thermoplastic resin tube to form two or more layers of the multilayer tubular body. The multi-layer tubular body is heated by exposing it to the heating furnace by exposing it to the inner atmosphere of the multi-layer tubular body and / or the depressurization of the outer atmosphere, or both atmosphere conditions. A method for producing a fiber-reinforced thermoplastic resin composite pipe including a step of fusion-bonding and integrating a resin layer, wherein a fiber-reinforced thermoplastic layer resin strip provided with a large number of through holes is used. A method for producing a fiber-reinforced thermoplastic resin composite pipe, comprising: