Composite pipe capable of being coiled and manufacturing method thereof

Abstract

The invention relates to the field of composite pipes, and discloses a composite pipe capable of being coiled and a manufacturing method thereof.The manufacturing method comprises the following steps that S1, a plastic core pipe extruder with an annular die head is used for extruding a plastic core pipe raw material, and a plastic core pipe layer (1) is formed through cooling shaping; s2, winding a reinforcing belt on the periphery of the plastic core pipe layer to form a belt type reinforcing layer (2), and extruding a plastic outer layer raw material to the outer side of the belt type reinforcing layer to form a reinforced thermoplastic plastic pipe with a plastic outer layer (3); and S3, spirally winding a wave-shaped protective belt (40) on the periphery of the reinforced thermoplastic pipe by using a winding machine to form a wave-shaped protective layer (4). According to the composite pipe capable of being coiled and manufactured through the manufacturing method, damage of construction impact to the belt type reinforcing layer can be reduced, the manufacturing method has no requirement for the wall thickness of the waveform protection belt, and therefore the production cost of the composite pipe capable of being coiled and provided with the outer protection layer is remarkably reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a composite pipe, and in particular to a method for manufacturing a coiled composite pipe. In addition, the present invention also relates to a coiled composite pipe. Background Art

[0002] Belt-reinforced thermoplastic pipe (referred to as belt-reinforced RTP pipe) is a high-performance pipe material. It significantly improves the mechanical strength, corrosion resistance and internal pressure resistance by adding reinforcing materials (such as glass fiber tape, aramid fiber tape, steel tape, steel cord tape, steel belt, etc.) to the thermoplastic matrix. Belt-reinforced RTP pipe is mainly used in the oil and gas industry and can partially replace steel pipe and thermosetting glass fiber reinforced plastic pipe.

[0003] Generally, the main goal of RTP pipes is to improve their ability to resist internal pressure. To this end, by adding the above-mentioned high-performance fiber materials, they can be used to transport fluids that generate large internal pressure. With the development of market demand, the ability of RTP pipes to resist external loads such as external pressure has also attracted attention in some application fields. For example, in response to the axial tension conditions such as the impact of waves in the marine environment and the vertical downward gravity of the downhole pipe, Chinese invention patent application CN115609981A provides a composite pipe with a core tube coated with a metal corrugated protective layer on the outside, and its manufacturing method and production equipment. During the manufacturing process, first, a trimming machine is used to cut off the two sides of the steel strip raw material released by the steel strip unwinder to eliminate the uneven or oxidized edges and other defective parts on both sides of the width of the steel strip raw material, and obtain a steel strip with a width suitable for coating the outer circumference of the core tube; then, the steel strip is bent by a steel strip cold bending forming unit and coated on the outside of the core tube; then, a longitudinal welding device is used to weld the longitudinal seam of the steel strip coated on the outside of the core tube along the axial direction of the core tube; finally, a corrugator is used to corrugate the outside of the steel strip so that the steel strip is formed into a metal corrugated protective layer. In addition, the manufacturing process may also include: a step of setting a sliding layer on the outside of the core pipe before coating the metal corrugated protective layer, a step of coating, winding an anti-corrosion layer and extruding a plastic outer protective layer on the outside of the metal corrugated protective layer after coating the metal corrugated protective layer, and a step of rolling up the formed composite pipe.

[0004] The above-mentioned prior art can significantly improve the adaptability of RTP pipes to harsh external environments. In particular, since the steel strip coated on the outside of the core pipe is continuous in the axial direction of the core pipe, it can also withstand axial tension such as vertical downward gravity when used as a downhole pipe. However, due to the need to implement operations such as longitudinal welding and corrugation, the coated steel strip should have an appropriate thickness (which is also conducive to bearing axial tension), which leads to high material and production costs of RTP pipes, and the welding and corrugation processes seriously restrict the improvement of production efficiency. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of high cost and low production efficiency of the reelable RTP pipe with an outer protective layer in the prior art, and to provide a method for manufacturing a reelable composite pipe. The manufacturing method is convenient for coating the outer layer of the reelable RTP pipe with a corrugated protective layer with a thin wall thickness, and significantly reduces the production cost and improves the production efficiency, prevents the reinforcement layer (especially the glass fiber reinforcement material) from being damaged by external forces, is suitable for laying in the field and underground in poor environment, and reduces the construction difficulty and construction cost.

[0006] In order to achieve the above object, the present invention provides a method for manufacturing a coilable composite pipe, comprising the following steps:

[0007] S1. The plastic core tube extruder having an annular die is used to extrude the plastic core tube raw material, and the plastic core tube layer is formed by cooling and shaping;

[0008] S2. The reinforcement tape is wound around the outer periphery of the plastic core tube layer to form a belt-type reinforcement layer, and a reinforced thermoplastic tube having a plastic outer layer is formed by extruding a plastic outer layer raw material to the outside of the belt-type reinforcement layer;

[0009] S3. Using a winding machine, spirally wind the corrugated protective tape around the outer circumference of the reinforced thermoplastic plastic pipe to form a corrugated protective layer.

[0010] Preferably, in step S2, one or more layers of glass fiber reinforced tape are spirally wound on the outer circumference of the plastic core tube layer to form the tape-type reinforcement layer that completely covers the outer circumference of the plastic core tube layer.

[0011] Preferably, in step S2, each layer of the glass fiber reinforced tape is bonded to the inner plastic core tube layer or an adjacent layer of the glass fiber reinforced tape by heating in an oven.

[0012] Preferably, the corrugated protective strip has at least two corrugated protrusions extending parallel to each other, and / or the wall thickness of the corrugated protective strip is 0.1mm-1mm, and / or the wave height of the corrugated protective strip is not greater than 10mm, and / or the corrugated protective strip comprises a corrugated steel strip having an inner and / or outer side coated with a plastic bonding layer.

[0013] Preferably, in step S3, the corrugated protective belt is spirally wound with a spiral diameter of 50 mm to 160 mm.

[0014] Preferably, step S3 comprises:

[0015] Before the corrugated protective tape is spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe, the reinforced thermoplastic plastic pipe is heated in an oven so that the plastic outer layer can be bonded to the corrugated protective tape as a whole, and / or,

[0016] After the corrugated protective tape is spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe, the corrugated protective layer is heated by high frequency so that the plastic outer layer can be bonded to the corrugated protective layer as a whole, and / or,

[0017] The corrugated protective tape is preheated adjacent to a winding position of the corrugated protective tape.

[0018] Preferably, in step S3, the corrugated protective tape is spirally wound so that edges of adjacent spirals are adjacent to, spaced apart from or overlapped with each other.

[0019] Preferably, the method further comprises step S4 performed after step S3: extruding an outer protective layer plastic onto the outer surface of the corrugated protective layer to form a plastic outer protective layer covering the corrugated protective layer.

[0020] The second aspect of the present invention provides a coilable composite pipe, comprising a reinforced thermoplastic plastic pipe and a corrugated protective layer coated on the outer circumference of the reinforced thermoplastic plastic pipe, wherein the reinforced thermoplastic plastic pipe has a plastic core tube layer and a belt-type reinforcement layer coated on the outer circumference of the plastic core tube layer, and the corrugated protective layer comprises a corrugated protective belt spirally wound on the outer circumference of the reinforced thermoplastic plastic pipe.

[0021] Preferably, the coilable composite pipe is manufactured using the above manufacturing method.

[0022] Through the above technical solution, the manufacturing method of the present invention forms a corrugated protective layer by spirally winding a corrugated protective belt around the outer periphery of a reinforced thermoplastic plastic pipe, thereby reducing the damage to the belt-type reinforcement layer in the coiled composite pipe caused by construction impact and improving the ability of the coiled composite pipe to resist external loads such as external pressure. Compared with the cold bending, longitudinal welding and corrugation processes used in the prior art to form a metal corrugated protective layer, the production method of the present invention of directly spirally winding a corrugated protective belt around the outer periphery of a reinforced thermoplastic plastic pipe has almost no requirements on the wall thickness of the corrugated protective belt, and allows the axial running speed of the pipe to be greatly increased during manufacturing, thereby significantly reducing the production cost of the coiled composite pipe with an outer protective layer and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of a coilable composite pipe according to a preferred embodiment of the present invention;

[0024] Figure 2 yes Figure 1 The pipe wall cross-section of the coilable composite pipe;

[0025] Figure 3 yes Figure 2 A magnified view of the local U in the figure;

[0026] Figure 4 is a half-section view of a coilable composite pipe according to another preferred embodiment of the present invention;

[0027] Figure 5 yes Figure 4 A magnified view of the local V in the middle;

[0028] Figure 6 is a cross-sectional view of a pipe wall of a coilable composite pipe according to another preferred embodiment of the present invention;

[0029] Figure 7 yes Figure 6 A magnified view of the local W in the middle;

[0030] Figure 8 Is manufacturing Figures 1 to 7 A cross-sectional view of a corrugated protective strip used in a coilable composite pipe;

[0031] Fig. 9 is a cross-sectional view of another corrugated protective belt used in manufacturing the coilable composite pipe of the present invention;

[0032] Fig.10 is a cross-sectional view of another corrugated protective belt used in manufacturing the coilable composite pipe of the present invention;

[0033] Fig.11 These are different waveforms of the corrugated protective belt that can be used in the coiled composite pipe of the present invention.

[0034] Description of Reference Numerals

[0035] 1-plastic core tube layer; 2-belt reinforcement layer; 3-plastic outer layer; 4-corrugated protective layer; 40-corrugated protective belt; 41-corrugated steel belt; 42-plastic bonding layer; 5-plastic outer protective layer. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0037] As mentioned above, belt-reinforced RTP pipes are used in the oil and gas extraction, gathering and transportation industries. According to the operating conditions, production costs and other factors, the reinforcement belt in the belt-reinforced RTP pipe can be selected as an appropriate type, such as glass fiber belt, aramid fiber belt, steel belt, steel cord belt, steel belt, etc. Among them, the glass fiber belt reinforced RTP pipe is cheap and easy to obtain, has good flexibility, and is easy to coil. The use of glass fiber belt as a reinforcement belt has attracted more and more attention. However, the glass fiber belt has the disadvantage of being easy to break. It is easy to break when a small curvature bend, hammering, collision, etc. occurs, which affects the overall performance of the pipe. Therefore, it is usually necessary to set a steel belt protective layer on the belt-reinforced RTP pipe to improve its adaptability to harsh external environments. However, for example, the manufacturing method provided by the prior art CN115609981A not only requires complex production equipment, high production costs and low production efficiency, but also because it needs to form a corrugated protective layer after rolling, welding and other processes, resulting in the reinforcement layer being squeezed during pipe production and is not suitable for the production of glass fiber reinforced RTP pipes, but is only suitable for steel curtain belt / steel belt RTP pipes, aramid belt RTP pipes, etc.

[0038] In the production of other types of pipes, such as steel-reinforced polyethylene spiral corrugated pipes commonly used in municipal drainage and sewage pipes, since they do not need to withstand internal pressure or only need to withstand a small internal pressure, a winding and compounding system with a winding and compounding roller group is usually used to spirally overlap plastic sheets to form a plastic inner layer and spirally compound reinforced sheets thereon to form a pipe wall reinforcement layer. Considering the need to resist external pressure in buried working conditions, the "ring stiffness" of such pipes is also considered to be an important parameter indicator. For this reason, corrugated steel strips can also be spirally wound on their outer walls to form a structural wall pipe. The inner diameter of the steel-reinforced polyethylene spiral corrugated pipe generally reaches 600mm to 3000mm. However, the production process and production equipment of such pipes are not suitable for reelable RTP pipes. The equipment and movement methods used in the production of reelable RTP pipes are completely different from those of steel-reinforced polyethylene spiral corrugated pipes.

[0039] The present invention provides a method for manufacturing a coilable composite pipe and a coilable composite pipe (coilable RTP pipe) that can be manufactured by the manufacturing method. The manufacturing method uses a spiral winding method to wrap a corrugated protective belt around the outer periphery of a reinforced thermoplastic plastic pipe to form a corrugated protective layer, thereby significantly improving the adaptability of the coilable RTP pipe to harsh external environments and the like. Therefore, compared with the manufacturing method of the prior art, the present invention can significantly reduce the production cost of a coilable composite pipe with an outer protective layer and improve production efficiency. It can be understood that, in addition to the step of forming the corrugated protective layer, the other steps proposed in CN115609981A (such as the step of manufacturing a core pipe, the step of extruding a plastic outer protective layer, and the step of winding, etc.) are also applicable to the manufacturing method of the present invention, so the following will mainly describe in detail the steps of forming the corrugated protective layer and the corrugated protective belt used and other related aspects.

[0040] Reference Figures 1 to 3 as well as Figure 8 As shown, according to a preferred embodiment of the present invention, a coilable composite pipe comprises a reinforced thermoplastic pipe and a corrugated protective layer 4 coated on the outer periphery of the reinforced thermoplastic pipe, wherein the reinforced thermoplastic pipe has a plastic core pipe layer 1 and a belt-type reinforced layer 2 coated on the outer periphery of the plastic core pipe layer 1, and the corrugated protective layer 4 is formed by a winding machine spirally winding a corrugated protective belt 40 on the outer periphery of the reinforced thermoplastic pipe. Thus, when external forces such as sea wave impact and violent construction occur, the corrugated protective layer 4 can protect the belt-type reinforced layer 2 in the reinforced thermoplastic pipe from damage, thereby improving the ability of the coilable composite pipe to resist external loads such as external pressure. Among them, the belt-type reinforced layer 2 can be a reinforced tape such as glass fiber, carbon fiber, aramid fiber, etc. coated on the outer periphery of the plastic core pipe layer 1, and the reinforced thermoplastic pipe can have one or more layers of reinforced tape. For example, the belt-type reinforced layer 2 formed by a glass fiber reinforced tape is prone to breakage when subjected to external pressure, which seriously damages the reinforcing effect of the belt-type reinforced layer 2. By coating the corrugated protective layer 4 on the outside, the environmental adaptability and service life of the coiled composite pipe can be effectively improved.

[0041] The corrugated protective tape 40 used for winding to form the corrugated protective layer 4 should have relatively good compression resistance and impact resistance. For this purpose, it is usually selected to be a metal protective tape (such as a corrugated steel tape 41) or include a metal tape layer. Figure 8 The corrugated protective belt 40 shown in the figure is also coated with a plastic bonding layer 42 on the inner and outer sides of the corrugated steel belt 41, so as to be bonded to the adjacent layers (plastic outer layer 3, plastic outer protective layer 5) by heating. In other embodiments, the corrugated protective belt 40 can also be coated with a plastic bonding layer 42 only on the inner side (the side facing the reinforced thermoplastic plastic pipe) or directly use the corrugated steel belt 41, respectively. Fig. 9 and Fig.10 shown.

[0042] Importantly, since the corrugated protective layer 4 is formed by spirally winding the corrugated protective belt 40 around the outer circumference of the reinforced thermoplastic plastic pipe without the need for processes such as welding and corrugation, the wall thickness of the corrugated protective belt 40 can be set to be very thin, such as 0.1mm-1mm, which greatly reduces the wall thickness of the corrugated protective layer relative to the existing coating method, thereby saving material costs and production costs. In addition, since there is no restriction on the process speed such as longitudinal welding and corrugation, the axial running speed of the pipe can be greatly increased during manufacturing, thereby effectively improving production efficiency.

[0043] Thus, the corrugated protection belt 40 used in the present invention has been formed with corrugated protrusions (convex ribs) before being wrapped around the outer circumference of the reinforced thermoplastic plastic pipe, and there is no need to perform corrugation after the coating is completed. Among them, the corrugated protection belt 40 can have an appropriate width and a suitable number of corrugated protrusions to ensure production efficiency. In the preferred embodiment shown in the figure, the corrugated protection belt 40 used has three corrugated protrusions extending in parallel to each other. In other embodiments, the corrugated protection belt 40 can have other numbers of corrugated protrusions, preferably at least two corrugated protrusions extending in parallel to each other.

[0044] According to the transportation requirements and in order to realize coiling, the coilable composite pipe is not only set to have a certain flexibility, but also the pipe diameter should not be too large, and the outer diameter of the pipe is usually 50mm to 160mm. In this case, the wave height of the corrugated protrusion on the corrugated protection belt 40 should not be too large, for example, usually not more than 10mm. In addition, if Fig.11 As shown, the corrugated protrusions can be formed into a variety of suitable shapes, such as arc-top arch, flat-top arch, sawtooth, sine wave, square wave, etc.

[0045] Generally, in order to fix the belt-type reinforcement layer 2 to the outer periphery of the plastic core tube layer 1, the reinforced thermoplastic plastic pipe may also include a plastic outer layer 3 formed on the outer side of the belt-type reinforcement layer 2. When the corrugated protective tape 40 is subsequently wound, the plastic outer layer 3 may be heated so that it can be bonded to the corrugated protective tape 40 wound on the outer side thereof after cooling. In addition, after the corrugated protective tape 40 is wound to form the corrugated protective layer 4, the outer protective layer plastic may be extruded to the outer side of the corrugated protective layer 4 to form a plastic outer protective layer 5. As mentioned above, the molding steps of the plastic outer layer 3, the plastic outer protective layer 5, etc. may be extruded, heated and cooled to shape using the same equipment and process as proposed in CN115609981A, which will not be described in detail here.

[0046] In a preferred embodiment, Figure 2 and Figure 3As shown, the corrugated protective tape 40 is spirally wound so that the edges of adjacent spirals are spaced apart from each other by a spacing A, whereby the plastic outer protective layer 5 can be bonded to the plastic outer layer 3 of the reinforced thermoplastic plastic pipe at the spaced position. Figure 4 and Figure 5 As shown, the corrugated protection band 40 can be spirally wound so that the edges of adjacent spirals are adjacent to each other (ie, the spacing is 0), thereby Figure 2 and Figure 3 The embodiment shown improves the ability to withstand internal and external pressure loads. In another preferred embodiment, as Figure 6 and Figure 7 As shown, the corrugated protective belt 40 can be spirally wound so that the edges of adjacent spirals overlap each other, such as making the corrugated protrusions of one of the adjacent spirals overlap the corrugated protrusions of the other (applicable to the case where the corrugated protective belt 40 has multiple corrugated protrusions extending in parallel with each other), so that the area not covered by the corrugated protective layer 4 in the aforementioned embodiment can be eliminated, and the ability to withstand loads such as internal and external pressures can be further improved, while also being able to withstand appropriate axial tension. It can be understood that the corrugated protective belt 40 wound in the above-mentioned different spiral winding methods can have no fixed connection relationship such as welding between the edges of adjacent spirals, thereby ensuring higher production efficiency. Compared with the axially continuous steel belt in the prior art, this significantly reduces the ability to withstand axial tension, but for scenes such as buried construction and seabed laying that do not require axial tension, the coiled composite pipe of the present invention can effectively reduce the damage to the belt-type reinforcement layer caused by external impact and pressure such as violent construction, and allow the use of a corrugated protective belt with a thinner wall thickness to form a corrugated protective layer and a relatively high axial running speed of the pipe, thereby significantly reducing the production cost of the coiled composite pipe with an outer protective layer and improving production efficiency.

[0047] The following is an explanation of the manufacturing method of the coilable composite pipe provided by the present invention, which can be used to manufacture the aforementioned coilable composite pipe. The molding process of the plastic core tube layer 1, the belt-type reinforcement layer 2, the plastic outer layer 3 and the plastic outer protective layer 5 (if any) can adopt the equipment and process provided by the prior art. The manufacturing method of the present invention comprises the following steps:

[0048] S1. Use a plastic core tube extruder with an annular die head to extrude the plastic core tube raw material, and form a plastic core tube layer 1 by cooling and shaping; S2. Wrap a reinforcement belt around the outer periphery of the plastic core tube layer 1 to form a belt-type reinforcement layer 2, and form a reinforced thermoplastic plastic pipe with a plastic outer layer 3 by extruding the plastic outer layer raw material to the outside of the belt-type reinforcement layer 2; S3. Use a winding machine to spirally wind a corrugated protective belt 40 around the outer periphery of the reinforced thermoplastic plastic pipe to form a corrugated protective layer 4.

[0049] Compared with the cold bending, longitudinal welding and corrugation processes used in the prior art to form the metal corrugated protective layer, the manufacturing method of the present invention directly spirally winds the corrugated protective belt 40 on the outer periphery of the reinforced thermoplastic plastic pipe. This production method has almost no requirements on the wall thickness of the corrugated protective belt 40, and allows the axial running speed of the pipe to be greatly improved during manufacturing, thereby significantly reducing the production cost of the coiled composite pipe with an outer protective layer and improving production efficiency. Specifically, as the reinforced thermoplastic plastic pipe runs axially, it can pass through the belt winding machine, so that the reinforcing belt released by it is spirally wound on the outer periphery of the reinforced thermoplastic plastic pipe during the operation of the belt winding machine to form the corrugated protective layer 4.

[0050] In the above step S2, the reinforcement tape used is preferably a glass fiber reinforcement tape, and one or more layers of the glass fiber reinforcement tape can be spirally wound on the outer peripheral surface of the plastic core tube layer 1 to form a belt-type reinforcement layer 2 that completely covers the outer peripheral surface of the plastic core tube layer 1. After each layer of the glass fiber reinforcement tape is wound on the plastic core tube layer 1, it can be heated in an oven to make it bonded to the outer peripheral surface of the plastic core tube layer 1 inside it or an adjacent layer of the glass fiber reinforcement tape, and fixed together by means such as air cooling.

[0051] The above step S3 may include at least one of the following sub-steps:

[0052] Before the corrugated protective tape 40 is spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe, the reinforced thermoplastic plastic pipe is heated in an oven so that its plastic outer layer 3 can be bonded to the corrugated protective tape 40 as a whole;

[0053] After the corrugated protective tape 40 is spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe, the corrugated protective layer 4 is heated by high frequency, and the heat is transferred to the inner plastic outer layer 3, so that the plastic outer layer 3 can be better bonded to the portion of the corrugated protective layer 4 that contacts the plastic outer layer 3;

[0054] A preheater may be provided near the winding position of the corrugated protective tape 40 to preheat the corrugated protective tape 40, so as to facilitate the adhesion of the corrugated protective tape 40 to the plastic outer layer 3 after the corrugated protective tape 40 is wound around the outer periphery of the reinforced thermoplastic plastic pipe. The preheater may be configured to heat the entire corrugated protective tape 40 or both sides thereof, or to heat only the side thereof that is in contact with the plastic outer layer 3.

[0055] As mentioned above, the diameter of the coiled composite pipe should not be too large, so in step S3, the spiral diameter of the spirally wound corrugated protective tape 40 can be 50 mm to 160 mm. In addition, as required, the corrugated protective tape 40 can be spirally wound so that the edges of adjacent spirals are adjacent, spaced or overlapped.

[0056] After step S3, the process may further include step S4 of forming a plastic outer protective layer 5: extruding an outer protective layer plastic onto the outer surface of the corrugated protective layer 4 to form a plastic outer protective layer 5 covering the corrugated protective layer 4. After the plastic outer protective layer 5 is cooled and shaped, the coiled composite pipe can be cut into appropriate lengths and coiled for storage and transportation.

[0057] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for manufacturing a coilable composite pipe, characterized in that: The steps include: S1. The plastic core tube raw material is extruded by a plastic core tube extruder having an annular die head, and the plastic core tube layer (1) is formed by cooling and shaping; S2. Wrapping a reinforcement tape around the outer periphery of the plastic core tube layer (1) to form a belt-type reinforcement layer (2), and forming a reinforced thermoplastic plastic tube having a plastic outer layer (3) by extruding a plastic outer layer raw material to the outer side of the belt-type reinforcement layer (2); S3. Using a winding machine, spirally wind the corrugated protective tape (40) around the outer circumference of the reinforced thermoplastic plastic pipe to form a corrugated protective layer (4).

2. The method for manufacturing a coilable composite pipe according to claim 1, characterized in that: In step S2, one or more layers of glass fiber reinforced tape are spirally wound on the outer circumference of the plastic core tube layer (1), and the tape-type reinforced layer (2) is formed which completely covers the outer circumference of the plastic core tube layer (1).

3. The method for manufacturing a coilable composite pipe according to claim 2, characterized in that: In step S2, each layer of the glass fiber reinforced tape is bonded to the inner plastic core tube layer (1) or an adjacent layer of the glass fiber reinforced tape by heating in an oven.

4. The method for manufacturing a coilable composite pipe according to claim 1, characterized in that: The corrugated protective strip (40) has at least two corrugated protrusions extending in parallel with each other, and / or the wall thickness of the corrugated protective strip (40) is 0.1 mm-1 mm, and / or the wave height of the corrugated protective strip (40) is not greater than 10 mm, and / or the corrugated protective strip (40) comprises a corrugated steel strip (41), the inner side and / or the outer side of the corrugated steel strip (41) being coated with a plastic bonding layer (42).

5. The method for manufacturing a coilable composite pipe according to claim 1, characterized in that: In step S3, the corrugated protective belt (40) is spirally wound with a spiral diameter of 50 mm to 160 mm.

6. The method for manufacturing a coilable composite pipe according to claim 1, characterized in that: Step S3 includes: Before the corrugated protective tape (40) is spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe, the reinforced thermoplastic plastic pipe is heated in an oven so that the plastic outer layer (3) can be bonded to the corrugated protective tape (40) as a whole, and / or, After the corrugated protective tape (40) is spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe, the corrugated protective layer (4) is heated by high frequency so that the plastic outer layer (3) can be bonded to the corrugated protective layer (4) as a whole, and / or, The corrugated protective tape (40) is preheated adjacent to a winding position of the corrugated protective tape (40).

7. The method for manufacturing a coilable composite pipe according to claim 1, characterized in that: In step S3, the corrugated protective tape (40) is spirally wound so that the edges of adjacent spirals are adjacent to, spaced apart from or overlapped with each other.

8. The method for manufacturing a coilable composite pipe according to claim 1, characterized in that: The method further comprises a step S4 performed after the step S3: extruding an outer protective layer plastic onto the outer surface of the corrugated protective layer (4) to form a plastic outer protective layer (5) covering the corrugated protective layer (4).

9. A coilable composite pipe, comprising a reinforced thermoplastic plastic pipe and a corrugated protective layer (4) coated on the outer periphery of the reinforced thermoplastic plastic pipe, wherein the reinforced thermoplastic plastic pipe comprises a plastic core pipe layer (1) and a belt-type reinforcement layer (2) coated on the outer periphery of the plastic core pipe layer (1), characterized in that: The corrugated protective layer (4) comprises a corrugated protective belt (40) spirally wound around the outer circumference of the reinforced thermoplastic plastic pipe.

10. The coilable composite pipe according to claim 9, characterized in that: The coilable composite pipe is manufactured by the manufacturing method according to any one of claims 1 to 8.

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