JPH06218841A - Manufacture of fiber reinforced thermoplastic resin composite tube - Google Patents

Abstract

PURPOSE:To provide a composite tube which is entirely bonded by fusing integrally and permanently wherein peeling of the interface does not occur even when it is used under a severe using condition that cooling and heating are repeated. CONSTITUTION:A standard-length matter of a composite tube 14 with a fiber composite body 12 covered with a thermoplastic resin tube 13 is set in a heating furnace B. Both ends of the composite tube 14 are blocked by a blocking plate 15 and an end of a gas passing tube 16 of a pressurizing pump 11 is inserted into a gas inflow port passing through the center of the blocking plate 15 provided in the front (right side in Figure). While the composite tube 14 is being heated, pressure of outside atmosphere is reduced by a pressure reducing pump 10 and pressure of inside atmosphere is increased by the pressurizing pump 11. Thus, the fiber composite body 12 is pressed firmly to the thermoplastic resin tube 13, bonded by fusing, and laminated. Deaeration of the fiber composite body 12 will be also performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced thermoplastic resin composite pipe having a thermoplastic resin pipe as the innermost layer and a fiber-reinforced thermoplastic resin composite laminated on the outer periphery thereof to form a multilayer pipe having two or more layers. Manufacturing method.

[0002]

2. Description of the Related Art Fiber-reinforced synthetic resin pipes are widely used as pipe members and structural members because they are lighter in weight than metal pipes and do not rust and have higher strength than synthetic resin pipes.

Conventionally, in this fiber-reinforced synthetic resin pipe, a reinforcing fiber impregnated with a liquid thermosetting resin is wound around a mandrel and heated in a heating furnace as it is to cure the resin.
It was manufactured by the method of taking out the mandrel (filament winding method), but since this type of composite pipe uses a thermosetting resin as the matrix resin of the reinforcing fiber layer, it is different from the thermoplastic resin pipe of the inner layer. The adhesive strength is weak, and when the composite pipe is used under conditions of repeated cold and heat,
There is a problem that interfacial peeling occurs between both layers due to the difference in linear expansion coefficient between the inner layer and the reinforcing fiber layer.

Therefore, in order to solve this problem, the present applicant has developed a technique of using a thermoplastic resin as a matrix resin for forming the reinforcing fiber layer. (JP-A-3-15
7591).

In this method for producing a fiber-reinforced thermoplastic resin composite pipe, a tubular body is continuously formed from a first sheet-shaped fiber composite for a reinforcing fiber layer in which a thermoplastic resin is held by continuous fibers arranged in a longitudinal direction. Molding step, while advancing the tubular body, along the inner surface thereof, the thermoplastic resin for the inner layer is extruded and laminated in a molten state, and the first reinforcing fiber layer in which reinforcing fibers are axially arranged and the thermoplastic resin inner layer A step of forming a two-layered tube consisting of a spiral sheet while heating a narrow sheet-shaped or string-shaped fiber composite for a second reinforcing fiber layer in which a continuous fiber holds a thermoplastic resin. Reinforced with a three-layer tube having a second reinforcing fiber layer in which reinforcing fibers are arranged in the circumferential direction on the outer surface of the first reinforcing fiber layer. This is a method of molding a thermoplastic resin composite pipe.

[0006]

In the above composite pipe, the adhesive strength between the inner layer and the reinforcing fiber layer is considerably improved as compared with the conventional one using a thermosetting resin as the matrix resin of the reinforcing fiber layer. Therefore, it can withstand sufficient use if it is used for a relatively short period of time under the condition of repeated cold heat, or under relatively mild conditions even under repeated heat and cold.

However, in the improved method for molding a fiber-reinforced thermoplastic resin composite tube, a large number of air bubbles are likely to be contained in the fiber-composite molding step used in the method, and on the other hand, each layer is laminated. Since the laminating pressure at that time is not sufficient, ambient air may be entrained in the interface between the thermoplastic resin tube and the fiber-reinforced thermoplastic resin composite or the interface between the reinforcing fiber layers. Then, these bubbles and entrapped air appear as so-called "voids" after molding, and a strong fusion bonding interface cannot be obtained.

[0008] Therefore, under relatively harsh conditions of repeated use of cold heat, for example, under high load of high temperature and high pressure, or when repeated cold heat for a long period of time, each interface easily peels off,
Above all, there is a strong tendency for interfacial peeling to occur at the interface between the first reinforcing fiber layer and the second reinforcing fiber layer, and it has not reached the point where it can be adopted with confidence under severe conditions.

The present invention has been made in order to solve the above problems, and its object is to use a thermoplastic resin tube as the innermost layer and to form a fiber-reinforced thermoplastic resin composite on the outer periphery thereof. As a method for producing a composite pipe consisting of forming a reinforcing fiber layer, the adhesive strength at the interface between the thermoplastic resin pipe and the reinforcing fiber layer, or when the reinforcing fiber layer is composed of multiple layers, is strong. The fiber-reinforced thermoplastic resin composite pipe in which interface separation does not occur even when used under considerably harsh conditions of use or for a considerably long period of time, and each interface is completely fused and integrated forever. To provide a method of manufacturing.

[0010]

The invention according to claim 1 is
"In the method for producing a fiber-reinforced thermoplastic resin composite pipe, in which a fiber-reinforced thermoplastic resin composite is laminated on the outer periphery of the thermoplastic resin pipe to obtain a multi-layer pipe having two or more layers, a fiber is provided outside the thermoplastic resin pipe. A multilayered tubular body is formed by coating the reinforced thermoplastic resin composite, and the multilayered tubular body is exposed to atmospheric pressure of the internal atmosphere of the multilayer tubular body, depressurization of the external atmosphere, or both of them. The method of manufacturing a fiber-reinforced thermoplastic resin composite pipe is characterized in that the thermoplastic resin pipe and the fiber-reinforced thermoplastic resin composite are fused and integrated with each other. In the invention described in 2, a tubular, sheet-shaped or string-shaped fiber-reinforced thermoplastic resin composite is provided around the outer periphery of a molten or almost solidified thermoplastic resin pipe which is continuously transferred in one direction. Set up and stack this to create two or more layers In the method for producing a fiber-reinforced thermoplastic resin composite pipe for obtaining a layered pipe, while the multi-layered pipe once molded and in a substantially solidified state is continuously transferred, its outer atmosphere is decompressed, or simultaneously with the decompression of the outer atmosphere, A method for producing a fiber-reinforced thermoplastic resin composite pipe, characterized in that the thermoplastic resin pipe and the fiber-reinforced thermoplastic resin composite are fused and integrated by exposing the atmosphere to a pressurized atmosphere and heating. This is the summary.

That is, according to the first aspect of the present invention, a fiber-reinforced thermoplastic resin composite is coated on the outside of a thermoplastic resin tube having a predetermined size so that a multilayer tubular body, that is, a completely laminated state is not reached yet. Then, by pressurizing the inside of the pipe or depressurizing the outside of the pipe, the entire pipe is exposed to a state where expansion pressure is applied and heated, and the expansion pressure is used to While the fusion of the interface is surely performed, the main point is to remove the contained bubbles. The invention according to claim 2 is, for example, extruding the thermoplastic resin for the inner layer in a molten state from an extruder, In the conventional manufacturing method in which a fiber-reinforced thermoplastic resin composite is arranged on the outer peripheral surface and laminated to obtain a multi-layer pipe having two or more layers, the outer periphery of the multi-layer pipe being continuously molded and transferred. Is heated under reduced pressure, or
Alternatively, the outer circumference should be kept under reduced pressure and the inside of the tube should be heated under pressure to give an expansion pressure to the entire tube, and the expansion pressure should be utilized to ensure fusion at each interface and removal of contained bubbles. Is the main point.

In the invention according to claim 1 or 2, the thermoplastic resin used for the thermoplastic resin tube which is the innermost layer is not particularly limited, and a thermoplastic resin suitable for the purpose of use of the tube is appropriately selected. And adopt it. Specific examples thereof include polyvinyl chloride, chlorinated polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyphenylene sulfide, polysulfone, and polyether / etherketone.

The above thermoplastic resins may be used alone or as a mixture of a plurality of them. In addition, a heat stabilizer, a plasticizer, an antioxidant, an ultraviolet absorber, a pigment, a filler, a processing aid, a modifier and the like are appropriately added to these thermoplastic resins.

In the invention according to claim 1 or 2, the thermoplastic resin as the matrix resin used in the fiber-reinforced thermoplastic resin composite may be any of the various resins exemplified for the inner layer. Further, when the resin for the inner layer and the matrix resin of the reinforcing fiber layer, or when the reinforcing fiber layer is a plurality of layers, the matrix resins of the respective reinforcing fiber layers do not necessarily have to be the same, but they are fused as a means of lamination. As long as the method is adopted, it is naturally necessary to select and use those having excellent compatibility.

The term "fusion bonding" as used herein means that both resins are heated to a molten state and then pressure-bonded, and after cooling, the fused interface is not easily broken. In the invention of claim 1 or 2, the fiber used in the fiber-reinforced thermoplastic resin composite is a roving-shaped or strand-shaped fiber made of continuous filaments having a diameter of 1 to several tens of μm.
Examples of this fiber include inorganic fibers such as glass fiber, carbon fiber and metal fiber, aramid fiber, vinylon, rayon,
All fibers usable as reinforcing fibers for synthetic resins, such as organic fibers such as cotton and hemp, are preferably used.

When the above-mentioned fiber composite is laminated on a thermoplastic resin tube to form a composite tube, the fibers used for each composite may be the same kind of fibers or different kinds of fibers. It may be.

In the invention according to claim 1 or 2, the width and thickness of the fiber-reinforced thermoplastic resin composite used are not particularly limited, but for example, when a string-shaped fiber composite is used, the diameter is 0. A material having a thickness of about 5 to 5 mm is preferably used, and in the case of using a narrow sheet-shaped (tape-shaped) fiber composite, a material having a thickness of about 0.1 to 10 mm is preferable. A thickness of about 3 mm is more suitable.

The amount of fibers in the fiber composite is usually 5
˜70% by volume. If it is less than 5% by volume, a sufficient reinforcing effect cannot be obtained, and if it exceeds 70% by volume, the thermoplastic resin is not sufficiently impregnated, making lamination and fusion difficult, and conversely the reinforcing effect becomes small.

The method of impregnating the thermoplastic resin between the filaments to retain the thermoplastic resin in the continuous fiber is, for example, a roving-like or strand-like continuous fiber material composed of a large number of filaments and a powdery thermoplastic resin. Any conventionally known method such as a method of passing the resin through a fluidized bed in which the resin is stably floating can be adopted.

In the invention of claim 1 or 2, the temperature at which the multilayer tubular body or the multilayer tube is heated is preferably not lower than the softening temperature of the thermoplastic resin forming the inner layer or the matrix resin of the fiber reinforced thermoplastic resin composite. A suitable temperature is selected depending on the thermoplastic resin used.

In the invention of claim 1 or 2, the applied pressure of the inner atmosphere varies depending on the size of the composite pipe, and therefore cannot be generally stated, but it is usually preferable to set it in the range of 0.01 to 10 kg / cm ^2. . Specifically, inner diameter = 25 mm,
When wall thickness = 3.5 mm, 0.01-3 Kg / cm ²
However, if it is 0.01 Kg / cm ² or less, sufficient lamination pressure cannot be obtained, and if it is 3 Kg / cm ² or more, the tube may swell and accuracy of the outer diameter may not be obtained. There is a need to.

On the other hand, the depressurizing force of the outside atmosphere cannot be unequivocally stated, but it is usually preferably 500 mmHg or more, and when it is less than 500 mmHg, sufficient laminating pressure and deaeration effect cannot be obtained. Further, in any of the first and second aspects of the invention, the use of both pressurized and depressurized atmospheres results in superior fusion bonding between the thermoplastic resin tube and the fiber-reinforced thermoplastic resin composite. Things are obtained.

[0023]

According to the first aspect of the present invention, the inner atmosphere of the multi-layer pipe is exposed to pressure or / and the outer atmosphere is depressurized and heated, and in the second aspect of the invention, the outer atmosphere is depressurized or Alternatively, since the inner atmosphere is exposed to a pressurized atmosphere and heated at the same time when the outer atmosphere is depressurized, the thermoplastic resin tube and the fiber-reinforced thermoplastic resin composite are fused and integrated,
Alternatively, at the stage of fusion-bonding and integrating the reinforcing fiber layers, a strong laminating pressure is applied to each interface, and the air bubbles contained in the composite or at the interface are surely scattered by this laminating pressure.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the following description, the term "front" refers to the right direction in the drawings. ． Inner thermoplastic resin, and the resin composition chlorinated polyvinyl chloride resin used as the matrix resin of the composite (chlorination degree of 67%, polymerization degree: 1000) 100 parts by weight of tin-based heat stabilizer 4 parts by weight of stearyl alcohol, 2 parts by weight Polyethylene wax 0.5 parts by weight. Production of Fiber Reinforced Thermoplastic Resin Composite As shown in FIG. 4, a roving-like bundle of glass fibers (4400 t) composed of filaments having a diameter of 23 μm.
ex) 10 in each (only two are shown in the drawing) 20 in total
Books are arranged in a sheet form in two layers, and the resin composition (particle size = about 250 μ) 2 is passed through a fluidized bed 4 formed by being fluidized by air 3 fed in the direction of the arrow. Then, the composition 2 is attached to the filaments of the glass fiber bundle 1, and the net-shaped glass fiber material 7 is sandwiched between the pair of heating rolls 5 heated to about 200 ° C.
Thus, the composition 2 adhered to the upper and lower filaments was heated and pressed, and was melted and fused and integrated with the fiber aggregate bundle 1 and the glass fiber material 7 to obtain a wide glass fiber composite 6.
The weight ratio of the resin to the glass fiber in this glass fiber composite 6 was resin: glass fiber = 70: 30. ． Example 1 The manufacturing method according to the present example relates to the invention according to claim 1, wherein the glass fiber composite body 6 is cut as a composite body, and width = 98 mm, length = 2000 mm, thickness = 0. ．
A 5 mm sheet-shaped glass fiber composite was prepared.

FIG. 1 is a sectional view showing an example of an apparatus suitable for use in the invention according to claim 1 together with its usage mode. In FIG. 1, 8 is a heating furnace heated to about 220.degree. Two-flute type annular rubber seals 9, 9 are attached to the openings at both ends by screws (not shown).
Reference numeral 10 denotes a decompression pump, which is a heating furnace 8 by a gas flow pipe.
It communicates with the inside of the cavity. Reference numeral 11 denotes a pressurizing pump, which is also communicated by a gas flow pipe with a gas inflow hole penetratingly provided in the center of a front side closing plate described later.

Next, the above-mentioned glass fiber composite 12 was made to have a length of 2000 mm, an outer diameter of 31 mm, and a wall thickness of 3.0 mm.
Thermoplastic resin tube made of chlorinated polyvinyl chloride resin 1
3 is wrapped around the outside in a sushi roll shape, the edges are closely abutted against each other, and heat fusion is performed with hot air to form a multilayer tubular body 14
Was formed. Then, as shown in FIG. 1, the multilayer tubular body 14 was inserted into a heating furnace 81 to hermetically seal the inside of the heating furnace 8. Further, both ends of the multilayer tubular body 14 are hermetically sealed by the disk-shaped closing plates 15 made of an elastic body, so that the inside of the multilayer tubular body 14 is sealed. As described above, one end of the gas flow pipe 16 from the pressurizing pump 11 is attached to the gas inlet hole in the center of the closing plate 15 attached to the front side.

After the preparation is completed in this way, the atmosphere outside the multilayer tubular body 14 is set to 700 by using the vacuum pump 10.
mmHg The pressure is reduced to 60 mmHg, and the pressure inside the multi-layer tubular body 14 is adjusted by using the pressure pump 11.
Pressurized to a pressure of 0.3 Kg / cm ² , heated for 3 minutes, and then taken out to obtain a thermoplastic resin tube 13 and a fiber composite 12
Outer diameter = 32 mm, where and were firmly fused and integrated,
A fiber reinforced thermoplastic resin composite tube having a dimension of wall thickness = 3.5 mm was obtained. The obtained composite pipe had no voids, and the fusion bond strength at each interface was such that it could withstand long-term use under severe conditions of repeated heat and cold. ． Example 2 The manufacturing method of this example relates to the invention according to claim 2, wherein the glass fiber composite 6 is used as a fiber composite.
Was cut to prepare a sheet-shaped glass fiber composite composed of a long and narrow product having a width of 20 mm and a thickness of 0.5 mm.

FIG. 2 is a diagram showing an example of an apparatus suitable for use in the invention described in claim 2 together with its usage mode.
The same reference numerals are used for the same devices as those in FIG.
In the figure, 17 is an extruder, and a die 18 and a cooling die 19 are attached to the front of the extruder in this order. Further, a central portion is provided in the die 18 and the cooling die 19. Is provided with an inner core 21 through which the gas flow passage 20 passes. The front end surface of the inner core 21 has a support member 22 made of a wire.
However, the wire 22 is extended to the front of a take-up machine, which will be described later, and a seal plate 23 is attached to the tip of the wire 22 to seal the inside of a continuously molded thermoplastic resin tube described later on the front side. 24 is a winding machine for the above-mentioned fiber composite 25, and 26 is a pressurized air source.

Using the apparatus as described above, first, a thermoplastic resin made of chlorinated polyvinyl chloride resin is extruded into a tubular shape from the extruder 17, while pressurized air is pressure-fed from a pressurized air source 26, The thermoplastic resin tube 27 up to the bulging portion of the inner core 21 was pressurized from the inside by being ejected from the opening provided in the side surface of the inner core 21 of the gas flow passage 20. Subsequently, the outside of the thermoplastic resin tube 27 is cooled by the cooling die 1
It was made to adhere to the inside of 9 and extruded and cooled.

While guiding the cooled thermoplastic resin pipe 27 to the front, the fiber composite 25 is wound around the outer periphery thereof by the winding machine 24.
Is continuously wound at an angle of 75 degrees with respect to the horizontal. Then, it is continuously introduced into the heating furnace 8 heated to 220 ° C.,
The decompression pump 10 is used to maintain the pressure at 700 mmHg for continuous decompression, and the pressurized air from the pressure air source 26 is ejected from the opening provided in the front end surface of the inner core 21 of the gas flow passage 20. The inside of the tube located in front of the inner core 21 was constantly pressurized with a pressure of 0.4 Kg / cm ² .

Then, the thermoplastic resin tube 27 and the fiber composite body 25 are fused and integrated by heating in the heating furnace 8 under a reduced pressure of the outer atmosphere and a pressurized pressure of the inner atmosphere, and subsequently arranged in front. While passing through a cooling sizing table 28 in which a water channel in which a cooling medium circulates is formed and being taken up by a take-up machine 29 set to a speed = about 2 m / min, an outer diameter = 32.2 mm and a wall thickness = 3 A fiber reinforced thermoplastic resin composite tube of 0.5 mm was obtained. The obtained composite pipe had no voids, and the fusion bond strength at each interface was such that it could withstand long-term use under severe conditions of repeated heat and cold. ． Example 3 The manufacturing method according to the present example relates to the invention according to claim 2, wherein as the fiber composite, the glass fiber composite 6 is cut to obtain a sheet-shaped fiber composite for the first reinforcing layer. As
A wide long product having a width of 88 mm and a thickness of 0.5 mm is prepared, and a thin long product having a width of 20 mm and a thickness of 0.5 mm is used as the sheet-like fiber composite for the second reinforcing layer. I prepared.

FIG. 3 is a diagram showing the entire apparatus divided into two parts. FIG. 3A is a diagram showing a substantially rear half of the entire apparatus, and FIG. 3B is a front half thereof. FIG. 7 is a diagram (partially overlapping portions). Further, the same reference numerals are used for the same parts and devices as those in FIGS. 1 and 2.

The apparatus shown in FIG. 3 has a rewinding roll 31 in which the sheet-shaped fiber composite 30 for the first reinforcing layer is wound.
And a first extruder 32 for extruding the thermoplastic resin for the inner layer
And a die 33 that is arranged in front of the die, has a tip portion bent forward at a right angle, and is capable of shaping the sheet-shaped fiber composite body 30 for the first reinforcing layer into a circular shape, and a front portion of the die 33. An inner core 34 provided on the shaft core and having a front bulge portion divided into two and having a constricted portion in the middle, and a cooling die 35 attached to the front portion of the die 33. , A support 22 made of a wire extending from the tip of the inner core 34 to the front of the take-up machine, a seal plate 23 attached to the tip of the support 22 and capable of sealing the air inside the pipe, and a second reinforcing layer A winding machine 24 for winding the sheet-shaped fiber composite 25,
The hot air generator 36, the same heating furnace 8 arranged in front of it as the one used in Examples 1 and 2, and the second extruder 37 for extruding the outer layer thermoplastic resin arranged in front of it.
And the outer layer coating die 3 provided at the tip of the second extruder 37.
8, a cooling sizing device 39 having a water channel in which a cooling medium circulates is formed in the front thereof, and a take-up device 29 arranged in front of the cooling sizing device 39.

At the rear of the mold 33, there is provided a gap into which the sheet-shaped fiber composite 30 for the first reinforcing layer can be inserted.
The sheet-shaped fiber composite body 30 for the first reinforcing layer is inserted through the gap, and the sheet is continuously shaped into a tubular body having an outer diameter of 28.8 mm and a thickness of 0.5 mm in the mold 33. A chlorinated polyvinyl chloride resin (average degree of polymerization = 1000) is extruded and laminated inside the sheet-shaped fiber composite 40 shaped into a tubular body, and at the same time, the gas flow passage 20 provided on the side surface of the inner core 34 is provided. The inner atmosphere was pressurized from the opening, and the outer surface of the two-layer pipe was brought into close contact with the cooling mold 35 to be cooled to obtain a two-layer pipe having an outer diameter of 28.8 and a wall thickness of 1.5 mm. 2 continuously molded
The layer tube is guided forward, and while the second reinforcing layer sheet-shaped fiber composite body 25 is heated by the hot air generator 36 by the winding machine 24, the layer tube is spirally wound at an angle of 75 ° with respect to the axial direction, A three-layer tube was used.

Subsequently, the material is introduced into a heating furnace 8 kept at 300 ° C. in front, and at least 700 mmHg of pressure is applied to the outside of the three-layer pipe by using a decompression pump 10 while heating at least the resin temperature at the interface of each reinforcing layer to a melting temperature. While maintaining the reduced pressure state, the inside of the tube was pressed at a pressure of 0.4 Kg / cm ² from the opening provided in the front end surface of the inner core 34 to fuse and strengthen the reinforcing layers.

Further, the three-layer pipe is guided to the outer-layer-coated mold 38, and the thermoplastic resin for the outer layer melt-plasticized by the second extruder 37 is extruded to the outer periphery of the second reinforced layer to coat it. Cooling sizing is performed by the sizing device 39,
A four-layer tube was used. A chlorinated polyvinyl chloride resin (average degree of polymerization = 1000) was used as the thermoplastic resin for the outer layer. The above series of steps were carried out while being continuously taken by the take-up machine 29 to continuously form a fiber-reinforced thermoplastic resin composite pipe having an outer diameter of 32.2 mm and a wall thickness of 3.5 mm. The obtained composite pipe has no voids, and the fusion strength at each interface is
It was able to withstand long-term use conditions under repeated cold and heat conditions.

[0037]

According to the first aspect of the present invention, the inner atmosphere of the multi-layer tube is heated under pressure and / or the outer atmosphere is depressurized, and the outer atmosphere is depressurized according to the second aspect of the invention, or Since the inner atmosphere is exposed to the pressurized atmosphere and heated at the same time as the depressurization of the outer atmosphere, the thermoplastic resin tube and the fiber-reinforced thermoplastic resin composite are fused and integrated, or the reinforcing fiber layers are fused to each other. At the stage of integration, a strong stacking pressure is applied to each interface, and the stacking pressure also surely disperses the bubbles contained in the composite and at the interface.

Therefore, a strong fusion-bonding interface can be obtained at each laminated interface, and delamination does not occur even under high load such as high temperature and high pressure or under repeated cold and heat for a long period of time. It is also possible to obtain a fiber-reinforced thermoplastic resin composite tube in which each interface is completely fused and integrated at all times.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an apparatus suitable for use in the invention according to claim 1 together with its usage.

FIG. 2 is a schematic explanatory view showing an example of an apparatus suitable for use in the invention according to claim 2 together with its usage mode.

FIG. 3 is a schematic explanatory view showing another example of an apparatus suitable for use in the invention described in claim 2 together with its usage mode.

FIG. 4 is a schematic explanatory view showing an example of an apparatus for producing a fiber-reinforced thermoplastic resin composite used in the fiber-reinforced thermoplastic resin composite pipe of the present invention.

[Explanation of symbols]

 6, 12, 25 Fiber reinforced thermoplastic resin composite 8 Heating furnace 10 Decompression pump 11 Pressure pump 12, 25, 30, Fiber composite 13, 27 Thermoplastic resin pipe 14 Multi-layer tubular body 15 Closure plate 17 Extruder 18, 33 Mold 19 Cooling mold 20 Gas flow passage 21, 34 Inner core 22 Support 23 Seal plate 26 Pressure air source 29 Take-off machine 32 First extruder 37 Second extruder

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Claims (2)

[Claims] 1. A method for producing a fiber-reinforced thermoplastic resin composite pipe, wherein a fiber-reinforced thermoplastic resin composite is laminated on the outer periphery of a thermoplastic resin pipe to obtain a multilayer pipe having two or more layers. An outer side is coated with a fiber-reinforced thermoplastic resin composite to form a multilayer tubular body, and the multilayered body is subjected to either an internal pressure of the multilayer tubular body or a reduced pressure of the outer atmosphere, or both of them under atmospheric conditions. A method for producing a fiber-reinforced thermoplastic resin composite pipe, which comprises exposing a tubular body to heat to fuse and integrate the thermoplastic resin pipe and the fiber-reinforced thermoplastic resin composite body. 2. A tubular member is provided around the outer periphery of a molten or substantially solidified thermoplastic resin pipe which is continuously transferred in one direction.
In a method for producing a fiber-reinforced thermoplastic resin composite pipe, in which a sheet-shaped or string-shaped fiber-reinforced thermoplastic resin composite is arranged and laminated to obtain a multi-layered pipe having two or more layers, a substantially solidified state once molded While continuing to transfer the multi-layer pipe in
The outer atmosphere is decompressed, or the inner atmosphere is exposed to a pressurized atmosphere at the same time as the outer atmosphere is decompressed and heated to fuse and integrate the thermoplastic resin pipe and the fiber-reinforced thermoplastic resin composite. A method for producing a fiber-reinforced thermoplastic resin composite pipe, comprising: