Crosslinked polyethylene fiber reinforced polyethylene composite pipe

Abstract

The utility model discloses a crosslinked polyethylene fiber reinforced polyethylene composite pipe, which belongs to the technical field of polyethylene composite pipes, and comprises a protective layer, a crosslinked polyethylene fiber reinforced layer and a lining pipe, the cross-linked polyethylene fiber used in the composite pipe is similar to polyethylene in modulus, good in compatibility and high in interface bonding capacity, and has high strength, creep resistance and low rigidity; the polyethylene matrix fixes the crosslinked polyethylene fibers and is thermally bonded with the lining pipe, and the crosslinked polyethylene fibers are further fixed on the lining pipe, so that unstable pressure bearing of the pipeline due to fiber slippage caused by deformation of the fibers in the pipeline installation and transportation process is prevented, and the overall structure of the pipeline is more stable.

Description

Technical Field

[0001] This application belongs to the field of polyethylene composite pipe technology, and in particular relates to a cross-linked polyethylene fiber reinforced polyethylene composite pipe. Background Technology

[0002] Fiber-reinforced thermoplastic composite pipes have been widely used in fields such as oil and gas transportation, with the fiber reinforcement layer providing most of the pipe's pressure-bearing capacity.

[0003] Commonly used fibers include polyester fiber, aramid fiber, and glass fiber. Patent CN1168877795A discloses an oil pipeline reinforced with basalt fiber as the reinforcing layer. The basalt reinforcing layer is obtained by curing basalt with phenolic resin. It has good strength and rigidity and can reduce dependence on non-renewable resources. However, its high rigidity cannot meet the requirements of continuous pipeline bending transportation and laying installation. Patent CN103075580B discloses a fiber-reinforced thermoplastic composite high-pressure pipeline. It uses glass fiber, aramid fiber, or carbon fiber as the pipeline reinforcing layer. The fibers are made into prepreg tape using thermoplastic resin materials, which gives the pipeline strong impact resistance and good heating performance. It can also produce continuous pipelines for bending transportation and laying.

[0004] In actual use of oil and gas pipelines, it has been found that pipelines made of the above-mentioned fibers will inevitably undergo deformations such as bending, rotation, and thermal expansion and contraction during transportation, installation and use. The above-mentioned fibers and the polyethylene material of the pipeline matrix have large differences in modulus, thermal expansion coefficient and interface strength, which often leads to problems such as fiber displacement, misalignment or partial breakage, causing pipeline failure. Summary of the Invention

[0005] The purpose of this application is to provide a cross-linked polyethylene fiber reinforced polyethylene composite pipe to solve the technical problems of high fiber rigidity, low interfacial strength between fiber and polyethylene matrix in existing polyethylene composite pipes, and easy fiber misalignment when the composite pipe is deformed.

[0006] To achieve the above objectives, the technical solution adopted in this application is: to provide a cross-linked polyethylene fiber reinforced polyethylene composite pipe, including a composite pipe body, the composite pipe body including a protective layer, a fiber reinforcement layer bonded to the inner side of the protective layer, and an inner liner pipe bonded to the inner side of the fiber reinforcement layer;

[0007] The fiber reinforcement layer is composed of cross-linked polyethylene fiber-coated tape wound around the fiber.

[0008] In one embodiment,

[0009] The cross-linked polyethylene fiber-coated tape is made of cross-linked polyethylene fibers and a polyethylene matrix.

[0010] In one embodiment,

[0011] An interface-reinforced film is formed on the surface of the cross-linked polyethylene fiber.

[0012] In one embodiment,

[0013] The cross-linked polyethylene fibers are encapsulated within the polyethylene matrix.

[0014] In one embodiment,

[0015] The interface-enhancing film is made of organosilicon and peroxide initiator.

[0016] In one embodiment,

[0017] The cross-linked polyethylene fiber has a single filament diameter of 10-100 nm and a cross-linking degree of 65-80%.

[0018] In one embodiment,

[0019] The cross-linked polyethylene fiber coating tapes are arranged in a triangular structure on the inner liner tube.

[0020] In one embodiment,

[0021] The protective layer is made of polyethylene; the inner liner is made of a combination of medium-density polyethylene and octene, high-density polyethylene, or ultra-high molecular weight polyethylene.

[0022] This application provides a cross-linked polyethylene fiber reinforced polyethylene composite pipe, using cross-linked polyethylene fiber as the reinforcing fiber. This fiber has extremely high compatibility with polyethylene, and after cross-linking, it is insoluble and does not melt. During processing, it can maintain its own shape and still exist in the polyethylene matrix in a fibrous form. This allows the fiber to adhere tightly to the inner layer of the pipe even when the composite pipe is deformed. The polyethylene matrix fixes the cross-linked polyethylene fiber and thermally bonds it to the inner liner pipe, further fixing the cross-linked polyethylene fiber to the inner liner pipe. This prevents the fiber from slipping due to deformation during pipe installation and transportation, which could cause unstable pipe pressure and make the overall pipe structure more stable. The interface reinforcement film bonds the polyethylene and the surface of the cross-linked polyethylene fiber, increasing the interfacial bonding force. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a composite pipe structure;

[0025] Figure 2 This is a schematic diagram of the side cross-sectional structure of a cross-linked polyethylene fiber-coated tape;

[0026] Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle.

[0027] Explanation of symbols in the diagram:

[0028] 1. Composite pipe body; 2. Protective layer; 3. Fiber reinforcement layer; 4. Inner liner; 5. Polyethylene matrix; 6. Cross-linked polyethylene fiber. Detailed Implementation

[0029] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, this application will be further described in detail. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.

[0030] The organosilicon is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltriisopropoxysilane; the peroxide initiator is one of 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane, dicumyl peroxide, di-tert-butyl hydroperoxide, or di-tert-butylperoxyisopropylbenzene; the mass ratio of organosilicon to peroxide initiator is 1:0.02-0.05.

[0031] In one embodiment, such as Figure 1 As shown, a cross-linked polyethylene fiber reinforced polyethylene composite pipe includes a composite pipe body 1, the composite pipe body 1 includes a protective layer 2, a fiber reinforcement layer 3 is bonded to the inner side of the protective layer 2, and an inner liner pipe 4 is bonded to the inner side of the fiber reinforcement layer 3.

[0032] Specifically, the protective layer 2 is made of polyethylene and is placed on the outermost layer to protect the internal structure; the inner liner 4 is made of high-density polyethylene and is in direct contact with the transported material. It is stable, durable, and together with the protective layer 2, protects the internal structure of the composite pipe.

[0033] Fiber reinforcement layer 3 is composed of cross-linked polyethylene fiber-coated tape wound around, such as Figure 2-3As shown, the cross-linked polyethylene fiber-coated tape is made of cross-linked polyethylene fiber 6 and polyethylene matrix 5. After forming an interfacial reinforcement film on its surface, the cross-linked polyethylene fiber 6 is coated inside the polyethylene matrix 5. The single filament diameter of the cross-linked polyethylene fiber 6 is 10 nm, and the degree of cross-linking is 65%. The cross-linked polyethylene fiber 6 is obtained by cross-linking polyethylene. The polyethylene matrix 5 is thermally bonded to the inner liner tube 4. After being heated, the cross-linked polyethylene fiber-coated tape is cross-wound onto the inner liner tube 4, arranged in a triangular structure to form a stable triangular fiber network. The cross-linked polyethylene fibers 6 are arranged in parallel within the polyethylene matrix 5.

[0034] An interface reinforcement film is formed on the surface of cross-linked polyethylene fiber 6. The interface reinforcement film is made of organosilicon and peroxide initiator. The cross-linked polyethylene fiber coating tape is immersed in organosilicon and peroxide initiator to form an interface reinforcement film. The interface reinforcement film bonds the polyethylene matrix 5 to the surface of cross-linked polyethylene fiber 6, increasing the interfacial bonding force.

[0035] In one embodiment, the inner liner 4 is made of a composition of medium-density polyethylene and octene.

[0036] In one embodiment, the inner liner 4 is made of ultra-high molecular weight polyethylene.

[0037] In one embodiment, the cross-linked polyethylene fiber 6 has a single filament diameter of 100 nm and a cross-linking degree of 80%.

[0038] In one embodiment, the cross-linked polyethylene fiber 6 has a single filament diameter of 45 nm and a cross-linking degree of 75%.

[0039] This application provides a cross-linked polyethylene fiber-reinforced polyethylene composite pipe, including a composite pipe body, a protective layer, a fiber reinforcement layer bonded to the inner side of the protective layer, and an inner liner bonded to the inner side of the fiber reinforcement layer. The fiber reinforcement layer is composed of cross-linked polyethylene fiber-coated tape wound around the pipe. This application uses cross-linked polyethylene fiber as the reinforcing fiber, which has extremely high compatibility with polyethylene. After cross-linking, it is insoluble and does not melt, and can maintain its own shape during processing, still existing in a fibrous form within the polyethylene matrix. This allows the fiber to remain tightly attached to the inner layer of the pipe even when the composite pipe deforms. The polyethylene matrix fixes the cross-linked polyethylene fiber and thermally bonds it to the inner liner, further fixing the cross-linked polyethylene fiber to the inner liner and preventing fiber slippage due to deformation during pipe installation and transportation, which could cause unstable pipe pressure and make the overall pipe structure more stable. An interface reinforcement film bonds the polyethylene and the surface of the cross-linked polyethylene fiber, increasing the interfacial bonding force.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cross-linked polyethylene fiber reinforced polyethylene composite pipe, comprising a composite pipe body, characterized in that, The composite pipe body includes a protective layer, a fiber reinforcement layer is bonded to the inner side of the protective layer, and an inner liner is bonded to the inner side of the fiber reinforcement layer. The fiber reinforcement layer is composed of cross-linked polyethylene fiber-coated tape wound around the fiber.

2. The cross-linked polyethylene fiber reinforced polyethylene composite pipe according to claim 1, characterized in that, The cross-linked polyethylene fiber-coated tape is made of cross-linked polyethylene fibers and a polyethylene matrix.

3. The cross-linked polyethylene fiber reinforced polyethylene composite pipe according to claim 2, characterized in that, An interface-reinforced film is formed on the surface of the cross-linked polyethylene fiber.

4. The cross-linked polyethylene fiber reinforced polyethylene composite pipe according to claim 2, characterized in that, The cross-linked polyethylene fibers are encapsulated within the polyethylene matrix.

5. A cross-linked polyethylene fiber reinforced polyethylene composite pipe according to claim 2, characterized in that, The cross-linked polyethylene fiber has a single filament diameter of 10-100 nm and a degree of cross-linking of 65-80%.

6. The cross-linked polyethylene fiber reinforced polyethylene composite pipe according to claim 1, characterized in that, The cross-linked polyethylene fiber coating tapes are arranged in a triangular structure on the inner liner tube.

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