Continuous fiber band reinforced polyethylene pipeline and preparation method thereof

Abstract

The invention relates to the field of fiber reinforced composite materials, and particularly discloses a continuous fiber band reinforced polyethylene pipeline and a preparation method thereof.The polyethylene pipeline is of a three-layer composite structure and comprises a lining layer, a reinforced core layer and an outer protection layer from inside to outside; the lining layer and the outer protective layer are made of thermoplastic PE, and the reinforced core layer is made of a fiber prepreg tape; the preparation method of the fiber prepreg tape comprises the following steps: spraying fibers with nano silicon dioxide to obtain surface modified fibers, taking the surface modified fibers as a middle layer, uniformly dividing toughened thermoplastic resin into a bottom layer and a surface layer, alternately laying the bottom layer and the surface layer in sequence, then feeding into a hot press for hot pressing, cooling and taking out to obtain the fiber prepreg tape. According to the invention, surface treatment is carried out on the fibers, and the resin used by the fiber prepreg tape of the middle layer material is adjusted, so that the pressure bearing capacity of the pipeline at the welding part is improved, the service life of the pipeline is prolonged, and the construction loss is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of fiber - reinforced composite materials, and particularly relates to a continuous fiber tape - reinforced polyethylene pipe and a preparation method thereof. Background Art

[0002] With the development of polymer materials, polyethylene pipes have currently replaced traditional metal pipes and are widely used in pipeline transportation fields such as building water supply, natural gas, and petroleum. They have strong corrosion resistance and little environmental damage. However, existing polyethylene pressure pipes still have problems such as poor tensile strength and short service life. To solve the problems of pure polyethylene pipes, composite pipe structures are mostly used at home and abroad. Among them, continuous fiber - reinforced polyethylene composite pipes are a new type of high - performance fiber - reinforced pipes, which generally have a multi - layer composite structure. For example, patent application CN117267482A discloses a fiber - reinforced large - diameter composite pipe and its forming process, which successively includes an inner lining layer, a reinforcing layer, a protective layer, and a rigidifying layer from the inside out. The reinforcing layer is fixed on the outer wall of the inner lining layer through inner connecting ribs, and the protective layer is fixed on the outer wall of the reinforcing layer through outer connecting ribs. This method is formed by cross - winding through the impregnation of glass fiber and thermosetting resin during the production process without pre - impregnation treatment in advance. Although the production rate is increased, there will be a problem of insufficient glass fiber infiltration, and the exposure of glass fiber will lead to a decrease in inter - layer adhesion and affect construction safety.

[0003] Regarding the above problems, when patent CN105034339B describes a processing method and equipment for a continuous fiber multi - layer winding thermoplastic composite pipe, it expounds that the inner layer of the pipe uses a bonded fiber pre - impregnated tape, and the pre - impregnated tape structure can improve the safety performance of the pipe and facilitate installation and construction. Although the pipe prepared with the bonded fiber pre - impregnated tape has good performance itself, in the traditional hot - melt weld pipe connection form, that is, when the two ends of the pipe are heated to the viscous flow state (melting temperature) within an appropriate temperature range and then the heating device is removed, and under a certain pressure, the viscous flow state cross - sections of the two pipe ends are fully contacted, and the polymer molecules migrate, diffuse, kink or wind around each other to form a welded joint. When facing various complex equipment shapes, the pressure - bearing capacity of the connection part will be reduced to a certain extent, which will correspondingly increase the probability of pipe accidents. Considering that the pressure - bearing capacity is generally proportional to the tensile strength, for this reason, the present invention provides a pipe that still has strong tensile strength after the processes of heating, cooling, and recrystallization. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a continuous fiber tape reinforced polyethylene pipe with a three-layer composite structure. The three layers of this pipe adopt the same molecular structure and can completely integrate into one body after melting to form a solid-wall pipe, achieving the integration of structural and functional functions. Moreover, by adjusting the resin used in the fiber prepreg tape of the middle layer material, the pressure-bearing capacity of the pipe at the welding part is improved, the service life of the pipe is extended, and construction losses are reduced.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] On the one hand, the present invention provides a continuous fiber tape reinforced polyethylene pipe. The polyethylene pipe has a three-layer composite structure, which is composed of an inner lining layer, a reinforcing core layer, and an outer protective layer from the inside to the outside. The inner lining layer and the outer protective layer are made of thermoplastic PE, and the reinforcing core layer is composed of fiber prepreg tapes. The preparation steps of the fiber prepreg tape are as follows: spray the fiber with nano-silica to obtain surface-modified fiber. Using the surface-modified fiber as the middle layer, the toughened thermoplastic resin is alternately stacked in the form of a bottom layer and a surface layer on average, and then sent to a hot press for hot pressing. After cooling and taking out, the fiber prepreg tape is obtained. The fiber is sprayed with nano-silica.

[0007] In some embodiments, the spraying amount of the nano-silica is 1-3 wt% of the fiber.

[0008] The present invention provides a multi-layer composite pipe. The middle layer uses continuous fiber prepreg tapes. Without much increase in the raw material cost, the performance of the pipe is greatly improved, enabling it to operate under higher pressure for a long time. Moreover, by surface-treating the fiber and adjusting the resin used in the fiber prepreg tape, the pressure-bearing capacity of the pipe at the connection part is improved, the service life of the pipe is increased, and construction losses are reduced.

[0009] In some embodiments, the fiber is any one of glass fiber, aramid fiber, and carbon fiber.

[0010] Glass fiber has relatively high tensile strength and modulus. Compared with aramid fiber and carbon fiber, its cost is relatively low and the processing difficulty is small. However, the toughness of glass fiber is poor and its anti-impact performance is slightly weak.

[0011] In some embodiments, the mass ratio of the total amount of the toughened thermoplastic resin to the surface-modified fiber is 1:(1.5-1.9).

[0012] In the case of a high fiber content, nano-silica is sprayed on the fiber surface to increase the roughness, enabling the resin melt to form "anchoring molecular chains" in the fiber grooves and enhancing physical interlocking. In addition, the sea-island structure of the toughened thermoplastic resin reduces the settlement of fibers during hot pressing to a certain extent, reducing the exposure of fibers during winding caused by uneven resin on both sides.

[0013] In some embodiments, the single-layer thickness of the fiber prepreg tape is 0.3 - 0.6 mm.

[0014] The fiber prepreg tape provided by the present invention is a sheet material formed by impregnating unidirectional continuous fibers parallel to each other with a molten thermoplastic resin. By controlling the mass ratio of the thermoplastic resin to the fiber, the problem of weakened interlayer bonding effect caused by fiber exposure on the surface of the impregnation tape is avoided.

[0015] In some embodiments, the preparation steps of the toughened thermoplastic resin are as follows:

[0016] S1. Mix dry polyethylene, glycidyl methacrylate, an initiator, an antioxidant, and a crosslinking agent evenly, then extrude and melt them at 140 - 190 °C for 3 - 5 min through a twin-screw extruder, cool, and pelletize to obtain a toughening agent.

[0017] S2. Conduct internal mixer blending of the toughening agent obtained in step S1 and high-density polyethylene at 150 - 220 °C, and process at a rotational speed of 40 - 80 rpm for 5 - 12 min to obtain the toughened thermoplastic resin.

[0018] In some embodiments, in step S1, the polyethylene is linear low-density polyethylene.

[0019] Preferably, the weight-average molecular weight of the linear low-density polyethylene is 20,000 - 50,000.

[0020] To ensure that the prepared pipeline reaches the required strength, the fiber prepreg tape usually needs to be kept in a molten state during multi-layer winding. The high-density polyethylene matrix used in the present invention can prevent the dripping of resin when the molten prepreg tape is directly wound layer by layer, ensure the average thickness of the intermediate layer, and ensure the qualification of the product.

[0021] However, the viscosity of high-density polyethylene (HDPE) is very high when it melts, and there are wetting and penetration vacancies for fibers during hot pressing. The toughened thermoplastic resin provided by the present invention can improve the wetting effect of the resin on the fibers. The epoxy groups in the glycidyl methacrylate molecules have high reactivity and can form hydrogen bonds with the polar functional groups on the fiber surface, improving the affinity with the fibers and promoting wetting.

[0022] Under ordinary process conditions, a toughening effect is obtained by directly mixing an epoxy group-containing reactive toughening agent with polyethylene. In this application, the toughening agent is first synthesized and then mixed, significantly improving the compatibility between linear low-density polyethylene and HDPE. The molecular structure of linear low-density polyethylene has almost no long branches, only some short branches, making the substance synthesized with glycidyl methacrylate also linear. On this basis, a crosslinking agent is introduced during the synthesis of the toughening agent to make the toughening agent partially three-dimensionally crosslinked. After mixing, the toughened thermoplastic resin forms an elastomeric phase with a "sea-island structure", which synergistically improves the impact strength with glass fiber.

[0023] During the preparation process, the epoxy group of glycidyl methacrylate can form a graft with linear low-density polyethylene, thereby forming good interfacial compatibility with HDPE. When this pre-synthesized toughening agent is mixed with HDPE, it can be more evenly dispersed in the matrix, reducing the phase separation phenomenon. This interfacial optimization enables the blend to form a more uniform microstructure during the hot melt welding process, reducing stress concentration and thus maintaining the tensile strength. At the same time, high-density polyethylene itself has a high crystallinity (about 70%-80%) and relatively high tensile strength. In the blend system of high-density polyethylene and linear low-density polyethylene, high-density polyethylene may serve as the continuous phase to provide a rigid framework, while the flexibility of linear low-density polyethylene (such as the elongation at break can reach 850%) supplements the toughness. During the kneading process, the molecular chains of high-density polyethylene form physical entanglements or partial co-crystallization with the toughening agent, further strengthening the overall structure.

[0024] The applicant found that using the above resin in the middle layer of the composite pipe can enable the welded part of the pipe to retain strong tensile strength.

[0025] In some embodiments, in step S1, the mass ratio of the polyethylene to glycidyl methacrylate is 1:(0.02-0.06).

[0026] In some embodiments, in step S2, the mass ratio of the toughening agent to high-density polyethylene is 1:(3-4).

[0027] On the other hand, the present invention provides a method for preparing the above-mentioned continuous fiber tape-reinforced polyethylene pipe, and the specific steps are as follows: (1) Extruding a PE sheet using a single-screw extruder and obtaining an inner liner through a coiling forming machine; (2) Forming a reinforced core layer on the obtained inner liner by winding a fiber pre-impregnated tape in a flat and circumferential manner using a winding machine; (3) Coating the surface of the reinforced core layer with a PE structure extruded by a single-screw extruder to obtain an outer protective layer, and then cooling and cutting to obtain a continuous fiber tape-reinforced polyethylene pipe.

[0028] In some embodiments, the thickness of the inner lining layer is 1 - 3 mm, the thickness of the reinforcing core layer is 1 - 2 mm, and the thickness of the outer protective layer is 1 - 2 mm; in step (2), the circumferential winding angle is 40 - 60°.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The continuous fiber tape reinforced polyethylene pipe provided by the present invention comprises an inner lining layer, a reinforcing core layer, and an outer protective layer from the inside to the outside. The three layers have the same molecular structure and can completely integrate into one body after melting to form a solid wall pipe, achieving the integration of structural and functional functions; this reinforcing core layer is composed of molten winding of fiber prepreg tapes. The use of continuous fiber prepreg tapes significantly improves the performance of the pipe under the condition of little increase in raw material cost, enabling it to operate under higher pressure for a long time.

[0031] 2. The present invention adjusts the resin used in the fiber prepreg tape, improves the pressure-bearing capacity of the pipe at the welding part, increases the service life of the pipe, reduces construction losses, uses high-density polyethylene as the resin matrix of the fiber prepreg tape, effectively prevents the dripping of the resin when the molten prepreg tapes are directly wound layer by layer, ensures the average thickness of the intermediate layer, and ensures the qualification of the product; on this basis, a toughening agent composed of linear low-density polyethylene and glycidyl methacrylate is used to improve the affinity between high-density polyethylene and the fiber, promote wetting, and reduce the voids existing during hot pressing; further, dicumyl peroxide is introduced into the toughening agent to promote partial cross-linking, so that the toughened thermoplastic resin forms an elastomeric phase with a "sea-island structure", which synergistically improves the impact strength with the glass fiber. At the same time, the mixed use of linear low-density polyethylene and high-density polyethylene helps to strengthen the overall structure, and with the interface optimization effect of glycidyl methacrylate, the welding part of the pipe retains good tensile strength.

[0032] 3. The present invention sprays nano-silica on the fiber surface to increase the roughness, promotes the fusion of a high content of glass fibers and the resin by physical occlusion and improving the resin wetting performance, and the sea-island structure of the toughened thermoplastic resin reduces the settlement of the fibers during hot pressing to a certain extent, reducing the exposure of the fibers during winding caused by uneven resin on both sides. Specific Embodiments

[0033] The following will describe the present invention in combination with specific implementation schemes. It should be noted that the following examples are examples of the present invention, only for explaining the present invention, and not for limiting the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the main idea or scope of the present invention.

[0034] It should be noted that unless otherwise specified, the raw materials used in the following Preparation Examples and Examples are all from any commercially available manufacturer: the high-density polyethylene has a model number of 8008H.

[0035] Preparation Example 1

[0036] The preparation steps of the toughened thermoplastic resin are as follows:

[0037] S1. Mix 5 kg of dry linear low-density polyethylene with a weight-average molecular weight of 3 ± 0.01×10⁴, 200 g of glycidyl methacrylate, 12.5 g of benzoyl peroxide, 10 g of antioxidant BHEB, and 20 g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane evenly, and then extrude and melt at 160 °C for 4 min through a twin-screw extruder, cool, and pelletize to obtain a toughening agent;

[0038] S2. Mix 5 kg of the toughening agent obtained in step S1 with 18 kg of high-density polyethylene by internal mixing and blending at 180 °C, and process at a speed of 60 rpm for 10 min to obtain the toughened thermoplastic resin.

[0039] Preparation Example 2

[0040] The difference between the preparation steps of the toughened thermoplastic resin and those of Preparation Example 1 lies in that: the linear low-density polyethylene in step S1 is replaced by the same amount of high-density polyethylene.

[0041] Preparation Example 3

[0042] The difference between the preparation steps of the toughened thermoplastic resin and those of Preparation Example 1 lies in that: the amount of glycidyl methacrylate used is 90 g.

[0043] Preparation Example 4

[0044] The difference between the preparation steps of the toughened thermoplastic resin and those of Preparation Example 1 lies in that: the amount of glycidyl methacrylate used is 310 g.

[0045] Preparation Example 5

[0046] The difference between the preparation steps of the toughened thermoplastic resin and those of Preparation Example 1 lies in that: the amount of high-density polyethylene used is 14 kg.

[0047] Preparation Example 6

[0048] The difference between the preparation steps of the toughened thermoplastic resin and those of Preparation Example 1 lies in that: the amount of high-density polyethylene used is 22 kg.

[0049] Preparation Example 7

[0050] The preparation steps of the toughened thermoplastic resin are as follows:

[0051] S1. Mix 5 kg of dry linear low-density polyethylene, 200 g of glycidyl methacrylate, 12.5 g of benzoyl peroxide, and 10 g of antioxidant BHEB evenly, then melt and extrude through a twin-screw extruder at 160 °C for 4 min, cool, and pelletize to obtain the toughening agent.

[0052] S2. Conduct internal mixing and blending of 5 kg of the toughening agent obtained in step S1 and 18 kg of high-density polyethylene at 180 °C, and process at a speed of 60 rpm for 10 min to obtain the toughened thermoplastic resin.

[0053] Preparation Example 8

[0054] The preparation steps of the fiber prepreg tape are as follows:

[0055] Spray continuous glass fibers with nano-silica (particle size 20 - 30 nm) at a spraying amount of 2 wt% of the fibers to obtain surface-modified fibers. Using 1.7 kg of the surface-modified fibers as the intermediate layer, evenly lay 1 kg of the toughened thermoplastic resin obtained in Preparation Example 1 in an alternating manner for the bottom layer and the surface layer, and then send it into a hot press for hot pressing at 200 °C for 10 min, and cool and take out to obtain a 0.4-mm-thick fiber prepreg tape.

[0056] Preparation Example 9

[0057] The difference in the preparation steps of the fiber prepreg tape from Preparation Example 8 is that the amount of the surface-modified fibers used is 1.4 kg.

[0058] Preparation Example 10

[0059] The difference in the preparation steps of the fiber prepreg tape from Preparation Example 8 is that the amount of the surface-modified fibers used is 2.0 kg.

[0060] Preparation Example 11

[0061] The difference in the preparation steps of the fiber prepreg tape from Preparation Example 8 is that the toughened thermoplastic resin is obtained from Preparation Example 2.

[0062] Preparation Example 12

[0063] The difference in the preparation steps of the fiber prepreg tape from Preparation Example 8 is that the toughened thermoplastic resin is obtained from Preparation Example 3.

[0064] Preparation Example 13

[0065] The preparation steps of the fiber prepreg tape are different from those of Preparation Example 8 in that: the toughened thermoplastic resin is obtained from Preparation Example 4.

[0066] Preparation Example 14

[0067] The preparation steps of the fiber prepreg tape are different from those of Preparation Example 8 in that: the toughened thermoplastic resin is obtained from Preparation Example 5.

[0068] Preparation Example 15

[0069] The preparation steps of the fiber prepreg tape are different from those of Preparation Example 8 in that: the toughened thermoplastic resin is obtained from Preparation Example 6.

[0070] Preparation Example 16

[0071] The preparation steps of the fiber prepreg tape are different from those of Preparation Example 8 in that: the toughened thermoplastic resin is obtained from Preparation Example 7.

[0072] Preparation Example 17

[0073] The preparation steps of the fiber prepreg tape are as follows:

[0074] 1 kg of the toughened thermoplastic resin obtained from Preparation Example 1 and 1.7 kg of continuous glass fibers are laid in sequence in an alternating laminated manner with the glass fibers as the intermediate layer and the toughened thermoplastic resin as the bottom and surface layers, and then fed into a hot press for hot pressing at 200 °C for 10 min, and after cooling and taking out, a 0.4-mm-thick fiber prepreg tape is obtained.

[0075] Example 1

[0076] A continuous fiber tape reinforced polyethylene pipe, which is a three-layer composite structure, consisting of an inner lining layer, a reinforcing core layer, and an outer protective layer from the inside to the outside; the inner lining layer and the outer protective layer are made of PE (grade JHMGC100S), and the reinforcing core layer is made of the fiber prepreg tape obtained from Preparation Example 8.

[0077] The preparation steps of the continuous fiber tape reinforced polyethylene pipe in this embodiment are as follows:

[0078] (1) Extrude a PE sheet using a single-screw extruder and obtain a 2-mm-thick inner lining layer through a coiling forming machine;

[0079] (2) On the obtained inner lining layer, form a 1.2-mm-thick reinforcing core layer by winding the fiber prepreg tape in a flat-laying manner and 55° circumferentially through a winding machine;

[0080] (3) Coating the surface of the reinforcing core layer with a PE structure extruded by a single-screw extruder to obtain a 1.2-mm-thick outer protective layer, and then cooling and cutting to obtain a continuous fiber tape reinforced polyethylene pipe.

[0081] Example 2

[0082] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 9.

[0083] Example 3

[0084] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 10.

[0085] Example 4

[0086] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 11.

[0087] Example 5

[0088] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 12.

[0089] Example 6

[0090] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 13.

[0091] Example 7

[0092] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 14.

[0093] Example 8

[0094] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 15.

[0095] Example 9

[0096] This embodiment provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Embodiment 1, except that the fiber pre-impregnated tape is obtained from Preparation Example 16.

[0097] Comparative Example 1

[0098] This comparative example provides a continuous fiber tape reinforced polyethylene pipe and its preparation method. The specific implementation manner is the same as that of Example 1, except that: the fiber prepreg tape is obtained from Preparation Example 17.

[0099] Performance test:

[0100] Cut the pipes of the above Examples 1-9 and Comparative Example 1. Take two 5-cm long pipes from each example for welding to obtain samples, and test the tensile strength and impact strength of the samples. The test of tensile strength refers to the standard ISO 527-3; the test of impact strength refers to the standard ISO 179-2.

[0101] The results are shown in Table 1.

[0102] Table 1

[0103] Tensile Strength (MPa) Impact Strength (J / M) Example 1 934 93 Example 2 916 87 Example 3 905 84 Example 4 867 78 Example 5 882 81 Example 6 922 90 Example 7 880 80 Example 8 909 84 Example 9 853 76 Comparative Example 1 891 82

[0104] It can be seen from the data in Table 1 that the pipe of Example 1 still has strong tensile strength after welding and has good impact resistance. Compared with Example 1, the amount of glass fiber in the fiber prepreg tape used in Examples 2-3 has changed. It can be seen from the data in the table that the tensile strength and impact resistance have decreased, which may be due to the excessive glass fiber affecting the recombination of the welded part; when the amount of glass fiber is too low, the tensile strength and impact resistance of the welded part will also decrease. Compared with Example 1, the toughened thermoplastic resin used in the reinforced core layer of Example 4 does not adopt the blend of high-density polyethylene and linear low-density polyethylene, resulting in a decrease in tensile strength; Examples 5-6 changed the amount of glycidyl methacrylate. When its amount decreases, it is not conducive to the fusion of glass fiber and resin, resulting in a decrease in tensile strength; Examples 7-8 changed the amount of high-density polyethylene. When the amount decreases, the impact strength decreases, and when it increases, it will affect the tensile strength. The toughened thermoplastic resin used in Example 9 lacks the elastomeric phase with a sea-island structure, resulting in a decrease in impact strength. It can be seen from Example 1 and Comparative Example 1 that spraying nano-silica on the surface of glass fiber effectively improves the fusion with resin, thereby improving the tensile strength and impact resistance.

[0105] The above-described embodiments and comparative examples do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, may make some modifications or decorations using the above-disclosed technical content to obtain equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and decoration made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A continuous fiber belt reinforced polyethylene pipe, characterized in that: The polyethylene pipe is a three-layer composite structure, which includes an inner lining layer, a reinforcing core layer, and an outer protective layer from the inside to the outside; the inner lining layer and the outer protective layer are composed of thermoplastic PE, and the reinforcing core layer is composed of a fiber prepreg tape; the preparation steps of the fiber prepreg tape are as follows: spraying the fiber with nano-silicon dioxide to obtain surface-modified fiber, using the surface-modified fiber as the middle layer, and laying the toughened thermoplastic resin in an alternating manner of a bottom layer and a surface layer, and then sending it into a hot press for hot pressing, cooling and taking it out to obtain the fiber prepreg tape.

2. The continuous fiber tape reinforced polyethylene pipe according to claim 1, characterized in that: The fiber is any one of glass fiber, aramid fiber and carbon fiber.

3. The continuous fiber tape reinforced polyethylene pipe according to claim 1, characterized in that: The mass ratio of the total amount of the toughened thermoplastic resin to the surface modified fiber is 1:(1.5-1.9).

4. The continuous fiber tape reinforced polyethylene pipe according to claim 1, characterized in that: The single-layer thickness of the fiber prepreg tape is 0.3-0.6 mm.

5. The continuous fiber tape reinforced polyethylene pipe according to claim 1, characterized in that: The preparation steps of the toughened thermoplastic resin are as follows: S1. Mix the dried polyethylene and glycidyl methacrylate with an initiator, an antioxidant and a crosslinking agent, and then melt and extrude them through a twin-screw extruder at 140 to 190° C. for 3 to 5 minutes, cool them, and pelletize them to obtain a toughening agent; S2. The toughening agent obtained in step S1 is mixed with high-density polyethylene at 150-220° C. and processed at a rotation speed of 40-80 rpm for 5-12 minutes to obtain a toughened thermoplastic resin.

6. The continuous fiber tape reinforced polyethylene pipe according to claim 5, characterized in that: In step S1, the polyethylene is linear low-density polyethylene.

7. The continuous fiber tape reinforced polyethylene pipe according to claim 5, characterized in that: In step S1, the mass ratio of polyethylene to glycidyl methacrylate is 1:(0.02-0.06).

8. The continuous fiber tape reinforced polyethylene pipe according to claim 5, characterized in that: In step S2, the mass ratio of the toughening agent to the high-density polyethylene is 1:(3-4).

9. A method for preparing a continuous fiber tape reinforced polyethylene pipe according to any one of claims 1 to 8, characterized in that: The specific steps are as follows: (1) A single screw extruder is used to extrude a PE sheet, and a crimping machine is used to obtain an inner liner; (2) forming a reinforced core layer by laying and circumferentially winding a fiber prepreg tape on the obtained inner liner layer through a winding machine; (3) The PE structure extruded by a single screw extruder is coated on the surface of the reinforced core layer to obtain an outer protective layer, which is then cooled and cut to obtain a continuous fiber belt reinforced polyethylene pipe.

10. The method for preparing a continuous fiber tape reinforced polyethylene pipe according to claim 9, characterized in that: The thickness of the inner lining layer is 1 to 3 mm, the thickness of the reinforcing core layer is 1 to 2 mm, and the thickness of the outer protective layer is 1 to 2 mm; in step (2), the circumferential winding angle is 40 to 60°.