JPH09207197A - Method and apparatus for molding reinforcing stripe material-containing thermoplastic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embed reinforcing stripe materials at an arbitrary position and to suppress the generation of a flow mark by arranging reinforcing stripe materials to the peripheral wall of the pipe of a molten resin sent in by an extruder in parallel to the axial direction of the pipe to continuously integrating the molten resin and the reinforcing strip materials to send out them. SOLUTION: The reinforcing stripe materials 2 wound around reels 4 are delivered by a reinforcing stripe material sending-out machine 5 while held under constant tension and sent into a die 6 for molding a pipe through movable reinforcing stripe material guides 7. The reinforcing stripe materials 2 sent into the die 6 are integrally extruded along with the thermoplastic resin 3 extruded in a molten state from an extruder 8 and sent into the resin passage in the die 6 through an adaptor 13 while held to the inner peripheral surface, thick-walled intermediate part or the outer peripheral surface of the resin passage. The pipe extruded from the die 6 is sized and cooled by a sizing die 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a thermoplastic resin pipe containing a reinforcing strip and an apparatus used therefor. More specifically, embedding the reinforcing strip in the axial direction improves the strength in the axial direction. Resistant to stretching and cutting, and also excellent in chemical resistance, abrasion resistance, gas barrier property, heat retention, workability, etc. Due to these characteristics, it is used for repairing and regenerating existing metal pipes and concrete pipes. The present invention relates to a method for molding a resin pipe suitable as an inner pipe for forming the same and an apparatus used therefor.

[0002]

2. Description of the Related Art Conventionally, a two-layer molding means has been known as a method of manufacturing a synthetic resin pipe in which a reinforcing strip is embedded in the axial direction. The two-layer molding means is to arrange an appropriate number of reinforcing strips in the axial direction on the outer side of an already molded inner tube, and mold the outer tube on the outer periphery thereof.
As a molding means of the synthetic resin pipe used for these inner tube and outer tube, after molding a tubular molten resin using an extruder equipped with a mold having an extrusion passage,
The method of solidifying by cooling is common. An adhesive or the like may be provided between the inner tube and the outer tube. According to the above-mentioned conventional means, the inner tube and the outer tube need to be molded twice, which requires time and labor for manufacturing, and the manufacturing cost is high.

Further, in Japanese Patent Laid-Open No. 63-260421, in order to solve the conventional problems, as a method of embedding a reinforcing strip in a synthetic resin pipe, an extrusion passage having an extrusion passage is formed in an extrusion die. Is provided in the vicinity of the extruder and the embedding ridge of the reinforcing strip that is provided so as to project into the extrusion passage downstream from the opening to the extrusion passage of this supply passage. It is disclosed that a means for supplying a reinforcing strip, which comprises a reinforcing strip supplying part, is provided. However, in this method, the embedded protruding ridges provided for introducing the reinforcing strip into the resin extrusion flow path interfere with the resin flow path, and flow marks are generated due to the flow of the resin. The pressure resistance of the resin pipe decreases, or the reinforcing pressure material is pushed out by the flow pressure of the resin onto the outer peripheral surface of the synthetic resin pipe,
It becomes difficult to embed the reinforcing strip in the middle portion of the wall thickness, and the adhesive force between the reinforcing strip and the resin is reduced, and peeling easily occurs. Further, in the case of the laminated pipe, there is a problem that the reinforcing strip cannot be embedded in the layers other than the outermost layer. In addition, the thermoplastic resin pipe containing a reinforcing material is required to have various softnesses such as chemical resistance, abrasion resistance, and gas barrier property, in addition to being flexible and excellent in flexibility.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention reduces the adhesive force between a reinforcing strip and a resin pipe when the reinforcing strip is continuously embedded in a resin layer. It is an object of the present invention to provide a method for molding a resin pipe and a device used therefor, which can embed a reinforcing strip at an arbitrary position and can suppress the generation of flow marks.

[0005]

Means for Solving the Problems The inventors of the present invention have made earnest studies in accordance with the above-mentioned object, and as a result, obstruct the passage of the molten resin by a reinforcing strip guide provided for introducing the reinforcing strip. So that there is no such problem, the reinforcing strip guide is installed parallel to the flow direction of the molten resin, and the reinforcing strip is embedded at an arbitrary position in the wall thickness direction of the pipe in parallel to the axial direction. Stable feeding and embedding, and extruding several kinds of resin layers integrally, and embedding a reinforcing strip between any resin layer or between resin layers in parallel to the axial direction. A method was found to complete the present invention. That is, a first aspect of the present invention is a method of extruding a molten resin into a cylindrical shape from a die, cooling and solidifying the same to form a pipe, in which a reinforcing strip material is introduced into a die through a reinforcing strip material guide in parallel with a resin flow path. The reinforcing strip is provided on the peripheral wall of the pipe of the molten resin supplied and fed by the extruder in parallel with the axial direction of the pipe, and the molten resin and the reinforcing strip are continuously fed out as an integral body, and sizing and The present invention relates to a method for molding a thermoplastic resin pipe containing a reinforcing strip characterized by being cooled and solidified. A second aspect of the present invention is that the reinforcing strip can be embedded at any position in the wall thickness direction of the pipe by adjusting the position of the tip of the reinforcing strip guide in the die. 1 relates to a method for molding a thermoplastic resin pipe containing a reinforcing strip. A third aspect of the present invention relates to a method for molding a thermoplastic resin pipe containing a reinforcing strip, which comprises means for holding the tension of the reinforcing strip constant. A fourth aspect of the present invention relates to a method for forming a thermoplastic resin pipe containing a reinforcing strip, which comprises forming a laminated pipe by using two or more kinds of the molten resin.
Further, a fifth aspect of the present invention is to provide a reinforcing strip material feeder for supplying the reinforcing strip material through the reinforcing strip material guide into the die in parallel to the resin flow path, and an extruder for extruding the molten resin into a cylindrical shape from the die.
A cooler that cools and solidifies the pipe extruded from the die,
In a thermoplastic resin pipe molding apparatus comprising a take-up machine and a take-up machine for taking a solidified pipe, a reinforcing strip material sent from a reinforcing strip material feeder can be embedded at an arbitrary position in the thickness direction of the pipe. Further, the present invention relates to a molding apparatus for a thermoplastic resin pipe containing a reinforcing strip material, comprising a die capable of axially moving the tip end position of the reinforcing strip material guide by a reinforcing strip material guide adjusting member.

According to the above construction, by supplying the reinforcing strip into the molten resin flowing in the extrusion passage, the reinforcing strip can be integrally embedded in the thick wall of the synthetic resin pipe to be molded. Since the laminate can be extruded as one body at the same time, the conventional molding process of two times or more can be completed in one time, and the manufacturing cost can be reduced. Further, since there is no protrusion in the extrusion passage that hinders the flow of the molten resin, it is possible to prevent the strength of the synthetic resin pipe from being deteriorated due to poor flow of the resin. The synthetic resin pipe manufactured by this method does not cause displacement of the reinforcing strip even when subjected to tensile force, vibration, compression force, etc., and the strength of the synthetic resin pipe in the axial direction is reinforced. The elongation can be suppressed.

Examples of the thermoplastic resin used in the present invention include polyolefin, polyamide, polyester, polyvinyl chloride, and thermoplastic resin elastomer.

Examples of the above-mentioned polyolefin include ultra low density polyethylene, linear low density polyethylene, polypropylene, propylene-ethylene copolymer, poly-1-butene and other α-olefin homopolymers or α-olefin mutual copolymers. Ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber and other α-olefin copolymer rubbers; low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer And a copolymer of ethylene and a polar group-containing comonomer. Further, as the thermoplastic resin elastomer,
Examples thereof include styrene type, vinyl chloride type, olefin type, polyester type, polyamide type and urethane type elastomers.

Of these, ultra-low-density polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, which are particularly excellent in flexibility,
Ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, thermoplastic resin elastomer and the like are preferable. In addition, these thermoplastic resins may be used alone or may be used as a composition of two or more kinds.

It is essential that the thermoplastic resin pipe of the present invention is soft and flexible, but the flexibility is expressed by the bending stiffness of the material forming the pipe after molding, and its measurement is measured from the pipe. Cut out the material. Bending stiffness is 200 to 5,000 kgf / cm ² , preferably 300 to 1,
It is in the range of 200 kgf / cm ² . The bending stiffness of the pipe is 2
If it is less than 00 kgf / cm ^2, it is too soft and is inferior in mechanical strength. Therefore, when pulling the pipe and laying and inserting it into the existing pipe, there is a possibility that cutting or breakage may occur, resulting in lack of reliability. On the other hand, those having a weight of more than 5,000 kgf / cm ² have insufficient flexibility, and it is difficult to deform and pull and insert the pipe into the existing pipe having many bent portions at room temperature.

In the present invention, the reinforcing strips embedded in the peripheral wall of the thermoplastic resin pipe in parallel with the axial direction include inorganic fibers such as glass fibers, carbon fibers, boron fibers and metal fibers,
Or single fibers such as aramid fibers, vinylon fibers, polyester fibers, polyamide fibers, synthetic or natural organic fibers such as cotton, bundled fibers, twisted yarns, flat yarns, etc., and woven fabrics, nonwoven fabrics, knitted fabrics, etc. using them There is a group of textile products such as tapes and strips. Also,
Other examples include metal materials such as iron, steel, brass, and copper, and twisted wires and wire ropes thereof.

As the material of the reinforcing strip, it is desirable to select a material whose elongation at break is close to the minimum value of elongation at yield of the thermoplastic resin constituting the pipe. When the elongation at break of the reinforcing strip and the elongation at yield of the thermoplastic resin are equal, the sum of the strengths of the reinforcing strip and the thermoplastic resin becomes maximum.
When the elongation at break of the reinforcing strip is larger than the elongation at yield of the thermoplastic resin, excessive elongation occurs in the pipe, which is not preferable.

The reinforcing strip can be embedded in any of the inner peripheral surface, the intermediate wall thickness portion and the outer peripheral surface of the peripheral wall of the thermoplastic resin pipe. In addition, the arranging method is generally arranged at equal intervals along the peripheral wall of the resin pipe, but in some cases, it may be arranged so as to be unevenly distributed on a part of the peripheral wall of the resin pipe. The number of reinforcing strips may be one or more,
Usually, it varies depending on the diameter of the pipe, and it is about 3 to 20, preferably 5 or more. Further, it is necessary that the adjacent reinforcing strips be sufficiently spaced from each other so as not to hinder the circumferential deformation of the resin pipe.

In the present invention, in order to improve the adhesive force between the thermoplastic resin and the reinforcing strip, the reinforcing strip may be previously subjected to a chemical or physical surface treatment. As the chemical surface treatment, a method of coating with a fatty acid such as stearic acid, oleic acid, palmitic acid or a metal salt thereof, paraffin wax, wax such as polyethylene wax or a modified product thereof, modified polyethylene, organic borane, organic titanate, etc. Is mentioned. Examples of the physical surface treatment include corona discharge treatment, plasma treatment, ultraviolet treatment and the like.

In the present invention, to the extent not departing from the gist of the present invention, an antistatic agent, an antifogging agent, an organic or inorganic filler, an antioxidant, a lubricant, an organic or inorganic pigment, an ultraviolet absorbing agent is added to a thermoplastic resin. Agents, dispersants, nucleating agents,
You may mix additives, such as a foaming agent, a flame retardant, and a crosslinking agent.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic view showing an example of a manufacturing process in which a reinforcing strip is embedded in a peripheral wall of a single-layer thermoplastic resin pipe in parallel with the axial direction. That is, the manufacturing process includes a reinforcing strip feeding process, an extrusion molding process, a cooling process and a winding process. In the reinforcing strip feeding process, the reinforcing strip 2 wound around the reel 4 is fed out by the reinforcing strip feeding device 5 while keeping the tension constant, and is extruded through the movable reinforcing strip guide 7 in the extrusion molding process. It is sent to the pipe forming die 6. The reinforcing strip can be kept free from slack by pulling it with a constant tension. In the extrusion molding process, the reinforcing strip 2 fed into the die 6 is extruded in a molten state from the extruder 8 while being held on the inner peripheral surface, the middle portion of the wall thickness or the outer peripheral surface in the resin flow path, and the adapter is pushed. It is extruded integrally with the thermoplastic resin 3 fed into the resin flow path in the die 6 via 13.
In the next cooling step, the pipe extruded from the die 6 is sized and cooled by the sizing die 9, and further sufficiently cooled by the cooling water tank 10. In the winding process, the solidified pipe is taken up by the take-up machine 11
Is continuously taken up by the winder, and is wound up by the winder 12 (not shown).

FIG. 2 is a schematic longitudinal sectional view showing an example of the die 6a used in the extrusion molding step shown in FIG. FIG.
Reinforcing strip 2 sent out from the reinforcing strip feeder 5 shown in FIG.
Is the molten thermoplastic resin 3 fed from the extruder 8 in the resin flow path of the die 6a through the reinforcing strip guide 7.
It is extruded together with. The tip of the reinforcing strip guide 7 is installed in the vicinity of the pipe molding portion inlet (position where the flow passage transitions into a pipe shape) 100a of the resin flow path, and its tip surface does not hinder the flow of the resin. It is cut obliquely along the resin flow path. The die 6a has a reinforcing strip guide adjusting nut 14 for feeding the reinforcing strip 2 to an arbitrary position in the pipe. The reinforcing strip material guide 7 is provided with a screw, and the reinforcing strip material guide adjusting nut 14 screwed onto the screw is used to move the tip end position of the reinforcing strip material guide 7 along the axial direction, whereby the reinforcing strip material guide 7 is moved. Material 2
Can be embedded at any position on the inner peripheral surface of the peripheral wall of the thermoplastic resin pipe, the middle portion of the wall thickness, or the outer peripheral surface. For example, in FIG. 2, if the tip end surface of the reinforcing strip material guide 7 is installed so as not to project into the resin flow path and to be flat with the outer peripheral surface, the reinforcing strip material 2 in the resin flow path will flow the molten resin. It is pressed against the outer peripheral surface of the resin flow path by pressure, and a thermoplastic resin pipe having a reinforcing strip disposed on the outer peripheral surface is formed. Also,
If the tip end surface of the reinforcing strip material guide 7 is installed so as to be located in the middle portion of the resin flow path, it is possible to form a thermoplastic resin pipe having the reinforcing strip material arranged in the middle portion of the wall thickness. Further, when the tip end surface of the reinforcing strip material guide 7 is installed close to the inner peripheral surface of the resin flow path, a thermoplastic resin pipe having the reinforcing strip material arranged on the inner peripheral surface is formed. In this case, Since the reinforcing strip guide 7 blocks the flow path of the molten resin, flow marks are likely to occur in the molded thermoplastic resin pipe due to poor flow. However, the generation of flow marks is suppressed as compared with the conventional method. The tip position of the reinforcing strip material guide 7 can be known by marking the reinforcing strip material guide adjusting nut 14 with a scale or a mark.

FIG. 3 is a schematic longitudinal sectional view showing another example of the die 6b used when forming a single-layer pipe. FIG.
In the example, the resin flow path is different from that in the case of FIG. 2, but the tip portion of the reinforcing strip guide 7 is installed in the vicinity of the pipe molding portion inlet 100b of the resin flow path, as in FIG. However, since the resin flow path to the pipe molding part is different from that in the case of FIG. 2,
The tip surface is cut in the opposite direction to the case of FIG. Also in this case, as in the case of FIG. 2, the position of the reinforcing strip 2 in the peripheral wall of the thermoplastic resin pipe can be changed by moving the tip position of the reinforcing strip guide 7. When the tip end position of the reinforcing strip material guide 7 is installed close to the outer peripheral surface of the resin flow path, a thermoplastic resin pipe having the reinforcing strip material arranged on the outer peripheral surface is formed. In this case,
Since the reinforcing strip material guide 7 blocks the flow path of the molten resin, a flow mark due to poor flow easily occurs in the molded thermoplastic resin pipe.

FIG. 4 is a cross-sectional perspective view showing an example of the thermoplastic resin pipe containing a single-layer reinforcing strip produced as described above. That is, FIG. 4A shows an example in which the reinforcing strip 2 is embedded in the outer peripheral surface of the resin pipe, FIG. 4B in the middle portion of the same thickness, and FIG. 4C in the inner peripheral surface. Show.

FIG. 5 is a schematic view showing an example of a manufacturing process in which a reinforcing strip is embedded in the peripheral wall of a two-layer thermoplastic resin pipe in parallel with the axial direction. The extruders 8a and 8b are used to supply the thermoplastic resins 3a and 3b, respectively, to form a two-layer resin pipe.

FIG. 6 is a schematic vertical sectional view showing an example of the die 6c used in the extrusion molding step shown in FIG. In this case, a two-layer pipe composed of an inner layer of the thermoplastic resin 3a and an outer layer of the thermoplastic resin 3b in which the reinforcing strip 2 is embedded is formed. The position of the reinforcing strip 2 within the thickness of the resin layer of the thermoplastic resin 3b can be arbitrarily changed.

FIG. 7 is a schematic longitudinal sectional view showing an example of another die 6d used for molding a two-layer pipe. In this case, the inner layer of the thermoplastic resin 3a in which the reinforcing strip 2 is embedded,
A two-layer pipe composed of the outer layer of the thermoplastic resin 3b is formed. The position of the reinforcing strip 2 within the thickness of the resin layer of the thermoplastic resin 3a can be arbitrarily changed.

FIG. 8 is a schematic longitudinal sectional view showing an example of a die 6e used in molding a three-layer pipe using three kinds of thermoplastic resins 3a, 3b and 3c. In this case,
From the inner layer side, the thermoplastic resins 3a and 3b and the reinforcing strip 2
To form a three-layer pipe in which the thermoplastic resin 3c in which is embedded in order is laminated. Further, the position of the reinforcing strip 2 within the thickness of the resin layer of the thermoplastic resin 3c can be arbitrarily changed.

FIG. 9 is a schematic vertical sectional view showing an example of another die 6f used when molding a three-layer pipe. In this case, the thermoplastic resin 3a in which the reinforcing strip 2 is embedded, the thermoplastic resin 3b and the same 3c are laminated in this order from the inner layer side 3
A layer pipe is formed. The position of the reinforcing strip 2 within the thickness of the resin layer of the thermoplastic resin 3a can be arbitrarily changed.

FIG. 10 is a schematic longitudinal sectional view showing an example of a die 6g for forming a five-layer pipe by mutually combining the thermoplastic resins 3a, 3b and 3c. In this case, the thermoplastic resin from the inner layer side is 3a / 3c / reinforcing strip embedded 3b.
A 5-layer pipe is formed by stacking / 3c / 3b in this order.
Then, the position of the reinforcing strip 2 in the thermoplastic resin 3b of the central layer can be arbitrarily changed.

FIG. 11 is a sectional perspective view showing an example of a thermoplastic resin two-layer pipe containing a reinforcing strip produced as described above. That is, by using the die 6c shown in FIG. 6 to extrude the thermoplastic resin 3a in the inner layer and the thermoplastic resin 3b in the outer layer together with the reinforcing strip 2 as shown in FIG.
The two-layer pipe shown in (b) and (c) can be molded.

FIG. 12 is a sectional perspective view showing an example of a thermoplastic resin two-layer pipe containing a reinforcing strip, similarly to the above. That is, by using the die 6d shown in FIG. 7, the thermoplastic resin 3a together with the reinforcing strip 2 in the inner layer and the thermoplastic resin 3 in the outer layer are used.
By extruding b, the two-layer pipe shown in FIGS. 12 (a), 12 (b) and 12 (c) can be molded.

When a thermoplastic resin pipe is produced using the dice 6c and the dice 6d, if the thermoplastic resins 3a and 3b are the same, a single layer is formed as in the case of using the dice 6a or 6b. You get a pipe. As described above, when the die 6a is used, flow marks are apt to occur when the reinforcing strip is arranged on the inner peripheral surface.
If a single-layer pipe is molded using c, a reinforcing strip can be arranged on the inner peripheral surface, and the generation of flow marks can be suppressed. Similarly, when a single-layer pipe having reinforcing strips on its outer peripheral surface is formed using the die 6d, the die 6b is used.
It is possible to suppress the flow mark that occurs when is used.

[0029]

EXAMPLES The present invention will be described in more detail based on the following examples. The test methods used for measuring the physical properties are as follows. (Physical property test method) Density: JIS K6760 compliant MFR: JIS K6760 compliant Tensile yield point load: JIS K6301 compliant Tensile elongation: JIS K6301 compliant Bending stiffness: JIS K7106 compliant Bending stiffness is a thermoplastic resin containing a resin reinforcing material after molding The material is cut out from and measured.

<Example 1> Density = 0.905 g / cm ³ , MF
R1.0g / 10 min, a flexural stiffness = 1,000 kgf / cm ² ultra-low density polyethylene (trade name: Nisseki Soft Rex D9
510, manufactured by Nippon Petrochemical Co., Ltd., was extruded at a molding temperature of 175 ° C. by a pipe molding machine (screw diameter = 60 mm, L / D = 20 extruder), while surface-treated with calcium stearate in advance. No. Tako thread (diameter 2.0)
mm of cotton twisted yarn, strength = 31.4 kg / piece), 16 pieces of reinforcing strips are supplied from the reinforcing strip material feeder 5 in FIG. 1 to the die 6a of the pipe forming machine shown in FIG. The tip end surface of the material guide 7 was installed so as to be flat with the outer peripheral surface of the resin flow path, and a thermoplastic resin pipe was molded. The thermoplastic resin pipe thus obtained has the following structure as shown in FIG.
Reinforcing strips on the outer peripheral surface of the pipe at equal intervals parallel to the axial direction 1
Six of them are arranged and buried. The inner diameter of the pipe is 5
The thickness was 0 mm, the wall thickness was 4 mm, the tensile load at yield point was 762 kgf, and the bending stiffness was 1,000 kgf / cm ² .

<Embodiment 2> As in Embodiment 1, except that the die 6a shown in FIG. 2 is used and the movable reinforcing strip guide 7 is installed so that its tip end face is located in the middle of the resin flow path. Example 1
A thermoplastic resin pipe was molded in the same manner as in. In the obtained thermoplastic resin pipe, as shown in FIG. 4 (b), the reinforcing strips are embedded in the middle portion of the thickness of the pipe in an array at equal intervals in parallel with the axial direction in 16 lines. The inner diameter of the pipe is 50 mm, the wall thickness is 4 mm, and the tensile yield point load is 76 mm.
It was 2 kgf and the bending stiffness was 1,000 kgf / cm ² .

<Embodiment 3> Same as Embodiment 1 except that the die 6a shown in FIG. 2 is used and the tip end surface of the movable reinforcing strip guide 7 is installed close to the inner peripheral surface of the resin flow path. The thermoplastic resin pipe was molded. In the obtained thermoplastic resin pipe, as shown in FIG. 4 (c), 16 reinforcing strips were embedded in the inner peripheral surface of the pipe at equal intervals in parallel to the axial direction. Due to the movable reinforcing strip guide 7 blocking the flow path of the molten resin, a flow mark due to poor flow of the resin was recognized in the obtained thermoplastic resin pipe, but this occurred compared to the conventional molding method. Was few. The inner diameter of the pipe was 50 mm, the wall thickness was 4 mm, the tensile yield point load was 762 kgf, and the bending stiffness was 1,000 kgf / cm ² .

<Embodiment 4> Similar to Embodiment 1, except that the die 6b shown in FIG. 3 is used and the tip end surface of the movable reinforcing strip guide 7 is installed so as to be flat with the inner peripheral surface of the resin flow path. Then, a thermoplastic resin pipe was molded. In the obtained thermoplastic resin pipe, as shown in FIG. 4 (c), 16 reinforcing strips were embedded in the inner peripheral surface of the pipe at equal intervals in parallel to the axial direction. The inner diameter of the pipe was 50 mm, the wall thickness was 4 mm, the tensile yield point load was 762 kgf, and the bending stiffness was 1,000 kgf / cm ² .

<Comparative Example 1> An attempt was made to mold a thermoplastic resin pipe by using the reinforcing strip feeding means disclosed in JP-A-63-260421. By adjusting the operating conditions, as shown in FIG. 4 (a), a thermoplastic resin pipe was obtained in which the reinforcing strips were embedded in the pipe outer peripheral surface at equal intervals in parallel with the axial direction. The joining strength between the reinforcing strip and the resin was weak, and the desired thermoplastic resin pipe could not be obtained. Therefore, in order to improve the joint strength, an attempt was made to embed the reinforcing strip in the middle portion of the resin layer thickness, but the flow pressure of the resin pushed the reinforcing strip to the outer peripheral surface, It was difficult to embed a reinforcing strip in the area. Moreover, flow marks were generated due to poor flow of the molten resin.

[0035]

EFFECTS OF THE INVENTION In the thermoplastic resin pipe molded according to the present invention, the reinforcing strip can be embedded at any position in the thickness direction of the pipe, and the generation of flow marks can be suppressed. . Further, the thermoplastic resin pipe of the present invention is a repair work by embedding reinforcing strips of fibers, textile products, wires, etc. in the peripheral wall in parallel with the axial direction to reinforce the axial strength and suppress the elongation. When used for, it is possible to prevent deformation and breakage of the pipe. Further, unlike the conventional method, there is no need to perform heating and deformation, so that workability and safety are excellent, and quick construction is possible. further,
Since a thermoplastic resin having a bending stiffness in a specific range is used and no reinforcing member is provided along the circumferential direction of the thermoplastic resin pipe, the pipe is highly flexible and has elasticity in the circumferential direction. ing. Therefore, even when it is applied to an existing pipe having many bent portions, the construction is easy and the inner wall of the existing pipe can be well adhered. The pipe having the above characteristics can be suitably used when repairing or rehabilitating an existing pipe such as a water pipe or a gas pipe.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a manufacturing process of the present invention.

FIG. 2 is a schematic vertical sectional view showing an example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 3 is a schematic longitudinal sectional view showing another example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 4 is a sectional perspective view showing an example of a thermoplastic resin pipe containing a reinforcing strip.

FIG. 5 is a schematic view showing another example of the manufacturing process of the present invention.

FIG. 6 is a schematic vertical sectional view showing another example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 7 is a schematic vertical sectional view showing another example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 8 is a schematic longitudinal sectional view showing another example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 9 is a schematic longitudinal sectional view showing another example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 10 is a schematic longitudinal sectional view showing another example of a die for molding a thermoplastic resin pipe containing a reinforcing strip.

FIG. 11 is a sectional perspective view showing another example of a thermoplastic resin pipe containing a reinforcing strip.

FIG. 12 is a cross-sectional perspective view showing another example of a thermoplastic resin pipe containing a reinforcing strip.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1
h, 1i thermoplastic resin pipe containing reinforcing strips 2 reinforcing strips 3 3a, 3b, 3c thermoplastic resin 4 reel 5 reinforcing strip feeder 6, 6a, 6b, 6c, 6d, 6e, 6f, 6g dice 7 reinforcement Strip material guide 8 Extruder 9 Sizing die 10 Cooling water tank 11 Pulling machine 12 Stripping machine 13 Adapter 14 Reinforcing strip material guide adjusting nut 100a, 100b Pipe forming part inlet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29L 23:00

Claims (5)

[Claims] 1. A method of extruding a molten resin into a cylindrical shape from a die, cooling and solidifying the same to form a pipe, in which a reinforcing strip material is fed into a die through a reinforcing strip material guide in parallel with a resin flow path and extruded. Disposing the reinforcing strip on the peripheral wall of the molten resin pipe fed by the machine in parallel with the axial direction of the pipe,
The molten resin and the reinforcing strip are continuously sent out as one unit,
A method for molding a thermoplastic resin pipe containing a reinforcing strip, which comprises sizing and cooling and solidifying. 2. The reinforcing strip can be embedded at any position in the thickness direction of the pipe by adjusting the position of the tip of the reinforcing strip guide in the die. A method for molding a thermoplastic resin pipe containing a reinforcing strip as described. 3. The method for molding a thermoplastic resin pipe containing a reinforcing strip according to claim 1, wherein a means for holding the tension of the reinforcing strip constant is used. 4. The method for molding a thermoplastic resin pipe containing a reinforcing strip according to claim 1, wherein a laminated pipe is molded by using two or more kinds of the molten resin. 5. A reinforcing strip material feeder for supplying the reinforcing strip material into the die through the reinforcing strip material guide in parallel with the resin flow path, an extruder for extruding the molten resin into a cylindrical shape from the die, and an extruder extruding from the die. In a molding machine for thermoplastic resin pipes, which consists of a cooler that cools and solidifies the solidified pipe, a take-up machine that draws the solidified pipe, and a winder, the reinforcing strip material sent from the reinforcing strip material feeder is used in the thickness direction of the pipe. Thermoplastic resin containing a reinforcing strip material, which is equipped with a die capable of axially moving the tip position of the reinforcing strip material guide by a reinforcing strip material guide adjusting member so as to be embedded in any position. Pipe forming equipment.