Glass fiber reinforced polyethylene composite pipe

Abstract

The utility model relates to a glass fiber reinforced polyethylene composite pipe. The problems that in the prior art, polyethylene is poor in affinity and compatibility, good interface bonding cannot be formed when the polyethylene and the polyethylene are compounded, and the mechanical property is poor are solved. The cable comprises a rigid inner layer, a positioning outer layer is arranged on the outer side of the rigid inner layer in the circumferential direction, a polyethylene flexible middle layer is arranged between the rigid inner layer and the positioning outer layer, and an inserting structure is arranged between the inner side of the polyethylene flexible middle layer in the circumferential direction and the outer side of the rigid inner layer in the circumferential direction. And the circumferential inner side of the positioning outer layer is arranged in the polyethylene flexible middle layer in a penetrating manner and is connected with a positioning locking structure of the inserting structure. The glass fiber reinforced plastic pipe fitting has the advantages that the structural strength is high, the impact resistance effect is good, the toughness of the pipe fitting is improved, good interface bonding can be formed between the glass fiber interlayer and the rigid inner layer, mutual entanglement and interlocking among molecular chains are formed, damage and deformation caused by the fact that polyethylene molecular chains are prone to diffusion in a long-term high-temperature environment are avoided, and the mechanical property is good.

Description

Technical Field

[0001] The utility model relates to the technical field of pipes, in particular to a glass fiber reinforced polyethylene composite pipe. Background Art

[0002] Polyethylene is a common, general-purpose plastic, widely used across various fields due to its excellent cost-effectiveness. Polyethylene pipes have been used for many years in industry and daily life. Their low glass transition temperature gives them excellent low-temperature resistance. However, for floor heating pipes, they are subject to prolonged use at higher temperatures. Exposure to high temperatures over time increases the mobility of polyethylene's molecular chains and segments, making them susceptible to creep, which can cause significant deformation or even damage during use. To improve this performance, researchers have employed methods such as cross-linking to create crosslinks within polyethylene or introducing inorganic materials, such as glass fiber, to restrict the movement of polyethylene chains. However, these pipes are complex to manufacture, resulting in high costs, long construction times, and low yields. Furthermore, the addition of inorganic materials, such as glass fiber, reduces their affinity and compatibility with the non-polar polyethylene, preventing a good interfacial bond between the two. Consequently, the inorganic material fails to provide any reinforcement, resulting in poor mechanical properties for the composite pipes.

[0003] To address the shortcomings of existing technologies, researchers have conducted extensive research and proposed a variety of solutions. For example, a Chinese patent document discloses a glass fiber composite polyethylene waterproof and insulated pipe [CN88207721]. This pipe comprises an outer protective layer of glass fiber composite polyethylene, placed over the insulation layer. The insulation layer can be composed of two or three composite insulation materials, or a single insulation material, depending on the operating temperature. This insulated pipe offers the advantages of easy construction, high temperature resistance, corrosion resistance, excellent waterproof and sealing properties, and the ability to thermally repair local damage. It can be installed overhead, directly buried, or in trenches. It is also suitable for insulation of refrigeration pipes.

[0004] The above solution has solved to a certain extent the problems of complex process, high cost, construction period and low yield of pipe fittings containing glass fiber in the existing technology. However, this solution still has many shortcomings, such as: polyethylene has weak affinity and compatibility, and the two cannot form a good interface bonding when combined. In this case, the inorganic material cannot play a reinforcing role, and the mechanical properties of the composite pipe fittings are poor. Summary of the Invention

[0005] The purpose of this utility model is to provide a glass fiber reinforced polyethylene composite pipe in order to solve the above problems.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a glass fiber reinforced polyethylene composite pipe, comprising a rigid inner layer, a positioning outer layer is provided on the circumferential outer side of the rigid inner layer, a polyethylene flexible middle layer is provided between the rigid inner layer and the positioning outer layer, and a plug-in structure is provided between the circumferential inner side of the polyethylene flexible middle layer and the circumferential outer side of the rigid inner layer, and a positioning locking structure is provided on the circumferential inner side of the positioning outer layer, which is passed through the polyethylene flexible middle layer and connected to the plug-in structure.

[0007] In the above-mentioned glass fiber reinforced polyethylene composite pipe, the rigid inner layer includes a high temperature resistant inner layer, a supporting outer layer is provided on the circumferential outer side of the high temperature resistant inner layer, and a glass fiber interlayer is provided between the high temperature resistant inner layer and the supporting outer layer.

[0008] In the above-mentioned glass fiber reinforced polyethylene composite pipe, the plug-in structure includes a plurality of positioning grooves arranged on the circumferential outer wall of the supporting outer layer, and the circumferential inner wall of the polyethylene flexible middle layer is provided with plug-in protrusions arranged corresponding to the positioning grooves.

[0009] In the above-mentioned glass fiber reinforced polyethylene composite pipe, a plurality of elastic top pressure parts arranged in a T-shape are provided on the circumferential outer wall of the rigid inner layer, a clearance groove for the elastic top pressure parts to pass through is provided on the glass fiber interlayer, and a top pressure force groove for the elastic top pressure parts to be inserted is provided in the plug-in protrusion.

[0010] In the above-mentioned glass fiber reinforced polyethylene composite pipe, a buffer gap is formed between the supporting outer layer and the polyethylene flexible middle layer and between two adjacent plug-in protrusions.

[0011] In the above-mentioned glass fiber reinforced polyethylene composite pipe, the positioning and locking structure includes a connecting groove arranged on the outer wall of the elastic top pressure part, and an insert positioning part is provided on the circumferential inner wall of the positioning outer layer. The positioning rod at the end of the insert positioning part is arranged in the connecting groove to position the elastic top pressure part.

[0012] In the above-mentioned glass fiber reinforced polyethylene composite pipe, the polyethylene flexible middle layer and the plug-in protrusion are provided with clearances for the plug-in positioning portion to pass through and extend into the positioning groove.

[0013] In the above-mentioned glass fiber reinforced polyethylene composite pipe, the circumferential outer wall of the positioning outer layer is covered with an anti-scratch film.

[0014] In the above-mentioned glass fiber reinforced polyethylene composite pipe, a POE interface flexible layer is provided between the high-temperature resistant inner layer and the glass fiber interlayer.

[0015] In the above-mentioned glass fiber reinforced polyethylene composite pipe, the inner wall of the high-temperature resistant inner layer is provided with a heat insulation layer.

[0016] Compared with the existing technology, the advantages of the present invention are: high structural strength, good impact resistance, and can play an effective heat insulation effect, improve the toughness of the pipe, so that the glass fiber interlayer can form a good interface bonding with the rigid inner layer, forming mutual entanglement and interlocking between molecular chains, avoiding the situation where polyethylene molecular chains are easily diffused in a long-term high temperature environment, resulting in damage and deformation, and having excellent mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view of the overall structure of the utility model;

[0018] Figure 2 yes Figure 1 Schematic diagram of the structure at A in FIG;

[0019] Figure 3 This is a schematic diagram of the polyethylene flexible middle layer structure in the present utility model;

[0020] Figure 4 It is a schematic diagram of the rigid inner layer structure in the present utility model;

[0021] In the figure: rigid inner layer 1, high temperature resistant inner layer 11, supporting outer layer 12, glass fiber interlayer 13, POE interface flexible layer 14, thermal insulation layer 15, positioning outer layer 2, polyethylene flexible middle layer 3, plug-in structure 4, positioning groove 41, plug-in protrusion 42, elastic top pressure part 43, yielding groove 44, top pressure force groove 45, buffer gap 46, positioning locking structure 5, connecting groove 51, plug-in positioning part 52, positioning rod 53, yielding gap 54. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0023] like Figure 1-4 As shown, a glass fiber reinforced polyethylene composite pipe includes a rigid inner layer 1, a positioning outer layer 2 is provided on the circumferential outer side of the rigid inner layer 1, a polyethylene flexible middle layer 3 is provided between the rigid inner layer 1 and the positioning outer layer 2, and a plug-in structure 4 is provided between the circumferential inner side of the polyethylene flexible middle layer 3 and the circumferential outer side of the rigid inner layer 1, and a positioning locking structure 5 is provided on the circumferential inner side of the positioning outer layer 2 and is passed through the polyethylene flexible middle layer 3 and connected to the plug-in structure 4.

[0024] The rigid inner layer 1 includes a high temperature resistant inner layer 11 , a supporting outer layer 12 is provided on the circumferential outer side of the high temperature resistant inner layer 11 , and a glass fiber interlayer 13 is provided between the high temperature resistant inner layer 11 and the supporting outer layer 12 .

[0025] The glass fiber interlayer 13 is made of an elastomer ethylene-octene copolymer grafted with polar groups. On the one hand, the POE grafted with polar groups forms chemical bonds and hydrogen bonds with the silanol groups on the surface of the glass fiber and the amino groups of the silane coupling agent through the polar groups, forming a strong bond with the surface of the glass fiber. At the same time, the POE molecular chain contains ethylene blocks and has good compatibility with the matrix polyethylene. It can form a high degree of diffusion between the molecular chains and form mutual entanglement and interlocking between the molecular chains, thereby forming a good interface bond between the reinforcing fibers and the resin matrix.

[0026] It can be seen that the plug-in structure 4 includes a plurality of positioning grooves 41 arranged on the circumferential outer wall of the supporting outer layer 12 , and the circumferential inner wall of the polyethylene flexible middle layer 3 is provided with plug-in protrusions 42 arranged corresponding to the positioning grooves 41 .

[0027] The polyethylene flexible middle layer 3 is spliced ​​and connected to the supporting outer layer 12 to improve the impact resistance and the structural toughness.

[0028] Furthermore, the rigid inner layer 1 is provided with a plurality of elastic pressing portions 43 arranged in a T-shape on the circumferential outer wall, the glass fiber interlayer 13 is provided with a clearance groove 44 for the elastic pressing portions 43 to pass through, and the plug-in protrusion 42 is provided with a pressing force groove 45 for the elastic pressing portions 43 to be inserted.

[0029] Through the force transmission of the elastic pressing portion 43 , a rapid stress response can be achieved when internal stress is applied.

[0030] Furthermore, a buffer gap 46 is formed between the supporting outer layer 12 and the polyethylene flexible middle layer 3 and between two adjacent plug-in protrusions 42 .

[0031] The buffer gap 46 can prevent the internal impact damage of the pipe and provide a movable gap.

[0032] Specifically, the positioning and locking structure 5 includes a connecting groove 51 arranged on the outer wall of the elastic top pressing part 43, and an insert positioning part 52 is provided on the circumferential inner wall of the positioning outer layer 2. The positioning rod 53 at the end of the insert positioning part 52 is arranged in the connecting groove 51 to position the elastic top pressing part 43.

[0033] More specifically, a clearance gap 54 is provided on the polyethylene flexible middle layer 3 and the plug-in protrusion 42 , through which the plug-in positioning portion 52 can pass and extend into the positioning groove 41 .

[0034] In detail, the circumferential outer wall of the positioning outer layer 2 is covered with an anti-scratch film.

[0035] The anti-scratch film can protect the circumferential outer wall of the positioning outer layer 2, and a waterproof layer is provided on the anti-scratch film.

[0036] Preferably, a POE interface flexible layer 14 is provided between the high temperature resistant inner layer 11 and the glass fiber interlayer 13.

[0037] After the POE interface flexible layer 14 forms chemical bonds and hydrogen bonds with the surface of the glass fiber, a flexible layer will be formed between the glass fiber and the matrix resin. The existence of the flexible layer can improve the ability of the composite pipe to absorb impact energy and prevent crack propagation by deformation, thereby greatly improving the toughness of the composite pipe.

[0038] In addition, the inner wall of the high temperature resistant inner layer 11 is provided with a heat insulating layer 15. The heat insulating layer 15 is used to improve the internal high temperature resistance performance.

[0039] To sum up, the principle of this embodiment is: by arranging a polyethylene flexible middle layer 3 between the rigid inner layer 1 and the positioning outer layer 2, and connecting them using a plug-in structure 4, the impact resistance of the inner wall of the pipe when subjected to force is improved, and a glass fiber interlayer 13 and a POE interface flexible layer 14 are arranged in the rigid inner layer 1. When subjected to critical force, the internal deformation is used to improve the ability of the composite pipe to absorb impact energy and prevent crack propagation, thereby greatly improving the toughness of the composite pipe.

[0040] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

[0041] Although this document frequently uses terms such as rigid inner layer 1, high temperature resistant inner layer 11, supporting outer layer 12, glass fiber interlayer 13, POE interface flexible layer 14, thermal insulation layer 15, positioning outer layer 2, polyethylene flexible middle layer 3, plug-in structure 4, positioning groove 41, plug-in protrusion 42, elastic pressing portion 43, clearance groove 44, pressure bearing groove 45, buffer gap 46, positioning locking structure 5, connecting groove 51, plug-in positioning portion 52, positioning rod 53, and clearance gap 54, the use of other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A glass fiber reinforced polyethylene composite pipe, comprising a rigid inner layer (1), wherein a positioning outer layer (2) is provided on the circumferential outer side of the rigid inner layer (1), characterized in that: A polyethylene flexible middle layer (3) is provided between the rigid inner layer (1) and the positioning outer layer (2), and a plug-in structure (4) is provided between the circumferential inner side of the polyethylene flexible middle layer (3) and the circumferential outer side of the rigid inner layer (1). A positioning locking structure (5) is provided on the circumferential inner side of the positioning outer layer (2) and is passed through the polyethylene flexible middle layer (3) and connected to the plug-in structure (4).

2. A glass fiber reinforced polyethylene composite pipe according to claim 1, characterized in that: The rigid inner layer (1) comprises a high temperature resistant inner layer (11), a supporting outer layer (12) is provided on the circumferential outer side of the high temperature resistant inner layer (11), and a glass fiber interlayer (13) is provided between the high temperature resistant inner layer (11) and the supporting outer layer (12).

3. A glass fiber reinforced polyethylene composite pipe according to claim 2, characterized in that: The plug-in structure (4) comprises a plurality of positioning grooves (41) arranged on the circumferential outer wall of the supporting outer layer (12), and the circumferential inner wall of the polyethylene flexible middle layer (3) is provided with plug-in protrusions (42) arranged corresponding to the positioning grooves (41).

4. A glass fiber reinforced polyethylene composite pipe according to claim 3, characterized in that: The rigid inner layer (1) is provided with a plurality of elastic top-pressing parts (43) arranged in a T-shape on its circumferential outer wall, the glass fiber interlayer (13) is provided with a clearance groove (44) for the elastic top-pressing parts (43) to pass through, and a top-pressing force groove (45) for the elastic top-pressing parts (43) to be inserted is provided in the plug-in protrusion (42).

5. The glass fiber reinforced polyethylene composite pipe according to claim 4, characterized in that: A buffer gap (46) is formed between the supporting outer layer (12) and the polyethylene flexible middle layer (3) and between two adjacent plug-in protrusions (42).

6. The glass fiber reinforced polyethylene composite pipe according to claim 5, characterized in that: The positioning locking structure (5) includes a connecting groove (51) arranged on the outer wall of the elastic pressing portion (43), and the circumferential inner wall of the positioning outer layer (2) is provided with an insert positioning portion (52). The positioning rod (53) at the end of the insert positioning portion (52) is arranged in the connecting groove (51) to position the elastic pressing portion (43).

7. The glass fiber reinforced polyethylene composite pipe according to claim 6, characterized in that: The polyethylene flexible middle layer (3) and the plug-in protrusion (42) are provided with a clearance gap (54) for the plug-in positioning portion (52) to pass through and extend into the positioning groove (41).

8. The glass fiber reinforced polyethylene composite pipe according to claim 1, characterized in that: The circumferential outer wall of the positioning outer layer (2) is covered with an anti-scratch film.

9. The glass fiber reinforced polyethylene composite pipe according to claim 2, characterized in that: A POE interface flexible layer (14) is provided between the high temperature resistant inner layer (11) and the glass fiber interlayer (13).

10. The glass fiber reinforced polyethylene composite pipe according to claim 9, characterized in that: The inner wall of the high-temperature resistant inner layer (11) is provided with a heat insulation layer (15).

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