Flexible sealing self-locking polyethylene winding solid-wall pipe and preparation method thereof

Abstract

The invention discloses a flexible sealing self-locking polyethylene winding solid-wall pipe and a preparation method thereof, and relates to the field of pipes. Wherein the flexible sealing self-locking polyethylene winding solid-wall pipe is prepared from the following raw materials in percentage by weight: 15 to 25 percent of nucleating master batch and the balance of high-density polyethylene, and the nucleating master batch is prepared from 28 to 32 percent of metallocene polyethylene, 18 to 22 percent of ultra-high molecular weight polyethylene and 50 percent of modified talcum powder through melting, plasticizing and granulating; the modified talcum powder is prepared by uniformly mixing talcum powder, a silane coupling agent, an aluminate coupling agent, stearic acid and olefin wax according to the weight ratio of 100: (0.8-1.2): (0.8-1.2): (1.5-2.5): (1.5-2.5). The flexible sealing self-locking polyethylene winding solid-wall pipe is low in shrinkage rate and small in fluctuation, the precision of the pipeline connecting position is high, and the water leakage phenomenon is not prone to occurring.

Description

Technical Field

[0001] The present application relates to the field of pipes, and in particular to a flexible sealed self-locking polyethylene wound solid wall pipe and a preparation method thereof. Background Art

[0002] There are many problems with the existing production process of flexible sealed self-locking polyethylene winding solid wall pipe (commonly known as top-drawn pipe). The traditional production method is to heat the polyethylene material through an extruder to melt and plasticize it into a "strip-shaped" blank, wrap it on a roller mold for hot continuous winding, and then use a lathe to process the socket after cooling.

[0003] Since the pipe adopts a flexible self-locking connection method, it relies on the teeth of the socket to be tightly connected, which requires extremely high dimensional accuracy of the socket. Once the fit is not good, it is very easy to leak during use. However, the high-density polyethylene used in production at this stage has a large molding shrinkage rate of about 2-4%, which makes it difficult to accurately control the dimensional accuracy of the socket processing in actual production. The dimensional error fluctuates widely, often exceeding the accuracy required for actual use, causing frequent leakage, seriously affecting product quality and performance. Summary of the invention

[0004] In the related art, the socket of the flexible sealed self-locking polyethylene wrapped solid wall pipe has a large shrinkage rate, which causes a large fluctuation range of the socket size error, making it easy for water leakage to occur at the connection between the pipes. In order to improve this problem, the present application provides a flexible sealed self-locking polyethylene wrapped solid wall pipe and a preparation method thereof. The flexible sealed self-locking polyethylene wrapped solid wall pipe has a low shrinkage rate and small fluctuation, the socket processing size accuracy is high, and it is not easy to leak.

[0005] A flexible sealed self-locking polyethylene wound solid wall pipe comprises 15-25wt% of a nucleating masterbatch and the remainder of high-density polyethylene. The nucleating masterbatch is obtained by melt-plasticizing and granulating 28-32wt% of metallocene polyethylene, 18-22wt% of ultra-high molecular weight polyethylene and 50wt% of modified talcum powder. The modified talcum powder is obtained by uniformly mixing talcum powder, a silane coupling agent, an aluminate coupling agent, stearic acid and olefin wax in a weight ratio of 100: (0.8-1.2): (0.8-1.2): (1.5-2.5): (1.5-2.5).

[0006] The present application nucleation masterbatch refines the grains through the heterogeneous nucleation of talcum powder, the regular crystallization of metallocene polyethylene optimizes the uniformity of shrinkage, and the molecular entanglement of ultra-high molecular weight polyethylene suppresses the synergistic effect of shrinkage, so that the molding shrinkage of the pipe is reduced, and the shrinkage fluctuation is small, which greatly improves the dimensional stability of the product, and effectively solves the problem of difficult control and leakage of the socket size accuracy caused by unstable shrinkage. However, considering the dispersibility problem of talcum powder, the present application first uses silane coupling agent, aluminate coupling agent, stearic acid and olefin wax to modify talcum powder for pretreatment, which is conducive to improving the dispersibility of talcum powder in polyethylene materials. Secondly, metallocene polyethylene and ultra-high molecular weight polyethylene are introduced into the nucleation masterbatch, and the problem of reduced material toughness caused by adding talcum powder is compensated at the same time, ensuring that the overall toughness of the pipe meets the use requirements, so that it is not easy to be damaged under complex installation and use environment. In addition, the addition of ultra-high molecular weight polyethylene can also give the pipe excellent wear resistance, so that it can better cope with the erosion of mud and sand mixture in underground drainage and sewage environment, and extend the service life of the pipe.

[0007] In some specific embodiments, the talc has a mesh size of 600-800 mesh and a diameter-to-thickness ratio of 10-20.

[0008] In some specific embodiments, the preparation method of the modified talc is as follows: The talc powder is heated and stirred, and when the temperature of the talc powder is raised to 80-85° C., a silane coupling agent and an aluminate coupling agent are added and stirred, and when the temperature of the talc powder is raised to 90-95° C., stearic acid is added and stirred, and when the temperature of the talc powder is raised to 100-105° C., olefin wax is added and stirred until uniformly dispersed to obtain modified talc powder.

[0009] The present application controls the addition temperature of silane coupling agent, silane coupling agent, aluminate coupling agent, stearic acid and olefin wax, which is conducive to better dispersion of each additive in talcum powder, coating talcum powder, and improving the dispersion effect of talcum powder in polyethylene material.

[0010] In some specific embodiments, the molecular weight of the metallocene polyethylene is 80,000-150,000.

[0011] In some specific embodiments, the molecular weight of the ultra-high molecular weight polyethylene is 4 million to 5 million.

[0012] In some preferred specific embodiments, the ultra-high molecular weight polyethylene is modified ultra-high molecular weight polyethylene, and the raw materials for preparing the modified ultra-high molecular weight polyethylene include side chain monoacrylate silicone oil, polyethylene glycol, ultra-high molecular weight polyethylene and peroxidation initiator in a weight ratio of (8.2-9.6): (2-4): 100: (0.01-0.015).

[0013] In the present application, when ultra-high molecular weight polyethylene adopts the modified ultra-high molecular weight polyethylene mentioned above in the present application, it is beneficial to improve the processing of the nucleating masterbatch and promote the uniform mixing of the various raw materials of the nucleating masterbatch. On the premise of ensuring the low shrinkage rate of the pipe, the wall thickness tolerance of the pipe can be further reduced and the wall thickness accuracy of the pipe can be improved.

[0014] The product of ultra-high molecular weight polyethylene modified by side chain monoacrylate silicone oil and polyethylene glycol, wherein the polyethylene glycol is coated on the surface of the ultra-high molecular weight polyethylene, which can improve the high viscosity of the ultra-high molecular weight polyethylene and enable the side chain monoacrylate silicone oil to complete the grafting reaction with the ultra-high molecular weight polyethylene at 180-190° C. In addition, the grafting amount of the side chain monoacrylate silicone oil is controlled within the scope of this application, which can take into account the wear resistance of the ultra-high molecular weight polyethylene.

[0015] In some specific embodiments, the polyethylene glycol is at least one of PEG6000 and PEG8000.

[0016] In some specific embodiments, the structural formula of the side chain monoacrylate silicone oil is as follows: ; The value of n is 45-50, and the value of m is 1.

[0017] In some specific embodiments, the method for preparing the modified ultra-high molecular weight polyethylene comprises the following steps: After polyethylene glycol and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C., side chain monoacrylate silicone oil and peroxidation initiator are added, and the temperature is maintained at 180-190° C. for grafting reaction to obtain modified ultra-high molecular weight polyethylene.

[0018] In the second aspect, the present application provides a method for preparing a flexible sealed self-locking polyethylene wound solid wall tube using the following technical solution: A method for preparing a flexible sealed self-locking polyethylene wound solid wall pipe comprises the following steps: S1. After the modified talc and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C., metallocene polyethylene is added, and the temperature is maintained at 180-190° C. for melting and plasticization, and then extruded and granulated to obtain a nucleating masterbatch; S2. Evenly mix the nucleating masterbatch and high-density polyethylene according to the ratio, feed them into the extruder, heat and melt the extruded billet at 180-190°C, wind the billet on a roller mold, cool it, and perform socket processing to obtain a flexible sealed self-locking polyethylene wound solid wall pipe.

[0019] In summary, this application at least includes the following beneficial technical effects: (1) The nucleating masterbatch of the present application reduces the molding shrinkage of the pipe through the synergistic effect of the heterogeneous nucleation of modified talcum powder to refine the grains, the regular crystallization of metallocene polyethylene to optimize the shrinkage uniformity, and the molecular entanglement of ultra-high molecular weight polyethylene to inhibit shrinkage, and the shrinkage fluctuation is small, which greatly improves the dimensional stability of the product and effectively solves the problems of difficult control of socket dimensional accuracy and water leakage caused by large and unstable shrinkage.

[0020] (2) In the present application, the ultra-high molecular weight polyethylene is modified by using side chain monoacrylate silicone oil and polyethylene glycol to produce a product of ultra-high molecular weight polyethylene, which is beneficial to improving the processing of the nucleating masterbatch and promoting the uniform mixing of the various raw materials of the nucleating masterbatch. On the premise of ensuring a low shrinkage rate of the pipe, the wall thickness tolerance of the pipe can be further reduced and the wall thickness accuracy of the pipe can be improved. DETAILED DESCRIPTION

[0021] The present application is further described below in conjunction with specific experiments.

[0022] Preparation Example [Preparation Example 1-1] Modified talcum powder, the raw materials for preparation include: Talc: 100 kg; in this preparation example, the talc is 600 mesh, and the diameter-to-thickness ratio is 10-20; Vinyl silane coupling agent: 0.8 kg; in this preparation example, the vinyl silane coupling agent specifically uses vinyl trimethoxy silane; Aluminate coupling agent UP-801: 1.2kg; Stearic acid: 1.5kg; Polyethylene wax A-C6A: 2.5kg; In this preparation example, the preparation method of modified talcum powder is as follows: Add talc powder into a reactor, heat and stir the talc powder, when the temperature of the talc powder reaches 80°C, add vinyl silane coupling agent and aluminate coupling agent UP-801 and stir, when the temperature of the talc powder reaches 90°C, add stearic acid and stir, when the temperature of the talc powder reaches 100°C, add polyethylene wax A-C6A and stir until uniformly dispersed to obtain modified talc powder.

[0023] [Preparation Example 1-2] Modified talcum powder, the raw materials for preparation include: Talc: 100 kg; in this preparation example, the talc is 600 mesh, and the diameter-to-thickness ratio is 10-20; Vinyl silane coupling agent: 1.2 kg; in this preparation example, the vinyl silane coupling agent specifically uses vinyl triethoxysilane; Aluminate coupling agent UP-801: 0.8kg; Stearic acid: 2.5kg; Polyethylene wax A-C6A: 1.5kg; In this preparation example, the preparation method of modified talcum powder is as follows: Add talc into a reactor, heat and stir the talc, when the temperature of the talc reaches 85°C, add vinyl silane coupling agent and aluminate coupling agent UP-801 and stir, when the temperature of the talc reaches 95°C, add stearic acid and stir, when the temperature of the talc reaches 105°C, add polyethylene wax A-C6A and stir until uniformly dispersed to obtain modified talc.

[0024] [Preparation Example 2-1] Modified ultra-high molecular weight polyethylene, the raw materials for preparation include: Side chain monoacrylate silicone oil: 8.2 kg; In this preparation example, the structural formula of the side chain monoacrylate silicone oil is as follows: ; The value of n is 45, and the value of m is 1; Polyethylene glycol 6000: 2kg; Ultra-high molecular weight polyethylene: 100 kg; in this preparation example, the ultra-high molecular weight polyethylene adopts the product of Korea Petrochemical U050, with a molecular weight of 5 million; Dicumyl peroxide: 0.01kg.

[0025] In this preparation example, the preparation method of modified ultra-high molecular weight polyethylene comprises the following steps: After polyethylene glycol 6000 and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C., side chain monoacrylate silicone oil and diisopropylbenzene peroxide are added, and the temperature is maintained at 180-190° C. for grafting reaction to obtain modified ultra-high molecular weight polyethylene.

[0026] [Preparation Example 2-2] Modified ultra-high molecular weight polyethylene, the raw materials for preparation include: 9.6 kg of side chain monoacrylate silicone oil; in this preparation example, the structural formula of the side chain monoacrylate silicone oil is as follows: ; The value of n is 50, and the value of m is 1; Polyethylene glycol 6000: 4 kg; Ultra-high molecular weight polyethylene: 100 kg; in this preparation example, the ultra-high molecular weight polyethylene adopts the product of Korea Petrochemical U050, with a molecular weight of 5 million; Dicumyl peroxide: 0.015kg.

[0027] In this preparation example, the preparation method of modified ultra-high molecular weight polyethylene comprises the following steps: After polyethylene glycol 6000 and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C., side chain monoacrylate silicone oil and diisopropylbenzene peroxide are added, and the temperature is maintained at 180-190° C. for grafting reaction to obtain modified ultra-high molecular weight polyethylene.

[0028] [Preparation Example 2-3] The modified ultra-high molecular weight polyethylene is different from [Preparation Example 2-1] in that the side chain monoacrylate silicone oil is replaced by an equal mass of vinyl-terminated hydroxyl-terminated silicone oil, in which the polymerization degree of the dimethylsiloxane segment is 45.

[0029] [Preparation Example 2-4] The modified ultra-high molecular weight polyethylene is different from [Preparation Example 2-1] in that polyethylene glycol 6000 is replaced by polyethylene glycol 10000 of equal mass.

[0030] [Preparation Example 2-5] The modified ultra-high molecular weight polyethylene is different from [Preparation Example 2-1] in that polyethylene glycol 6000 is not added.

[0031] Example [Example 1] A flexible sealed self-locking polyethylene wound solid wall tube. The raw materials for preparing the flexible sealed self-locking polyethylene wound solid wall tube include 15wt% nucleating masterbatch and 85wt% high-density polyethylene (Formosa Plastics 8001), wherein the nucleating masterbatch is obtained by melt-plasticizing and granulating 32wt% metallocene polyethylene (ExxonMobil 1018), 22wt% ultra-high molecular weight polyethylene (Korea Petrochemical U050) and 50wt% modified talc powder [Preparation Example 1-1].

[0032] In this embodiment, the preparation method of the flexible sealed self-locking polyethylene wound solid wall pipe comprises the following steps: S1. After the modified talc powder and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C. according to the ratio, the metallocene polyethylene is added, and the temperature is maintained at 180-190° C. for melting and plasticization, and then extruded and granulated to obtain a nucleating masterbatch; S2. Evenly mix the nucleating masterbatch and high-density polyethylene according to the ratio, feed them into the extruder, heat and melt the extruded billet at 180-190°C, wind the billet on a roller mold, cool it, and perform socket processing to obtain a flexible sealed self-locking polyethylene wound solid wall pipe.

[0033] [Example 2] A flexible sealed self-locking polyethylene wrapped solid wall tube, which differs from [Example 1] in that: the raw materials for preparing the flexible sealed self-locking polyethylene wrapped solid wall tube include 25wt% nucleating masterbatch and 75wt% high-density polyethylene (Formosa Plastics 8001), wherein the nucleating masterbatch is obtained by melt-plasticizing and granulating 28wt% metallocene polyethylene (ExxonMobil 1018), 22wt% ultra-high molecular weight polyethylene (Korea Petrochemical U050) and 50wt% modified talc powder [Preparation Example 1-2].

[0034] [Example 3] A flexible sealed self-locking polyethylene wound solid wall tube, which differs from [Example 1] in that: in the nucleating masterbatch, the ultra-high molecular weight polyethylene is replaced by the modified ultra-high molecular weight polyethylene prepared in [Preparation Example 2-1].

[0035] [Example 4] A flexible sealed self-locking polyethylene wound solid wall tube, which differs from [Example 1] in that: in the nucleating masterbatch, the ultra-high molecular weight polyethylene is replaced by the modified ultra-high molecular weight polyethylene prepared in [Preparation Example 2-2].

[0036] [Example 5] A flexible sealed self-locking polyethylene wound solid wall tube, which differs from [Example 1] in that: in the nucleating masterbatch, the ultra-high molecular weight polyethylene is replaced by the modified ultra-high molecular weight polyethylene prepared in [Preparation Example 2-3].

[0037] [Example 6] A flexible sealed self-locking polyethylene wound solid wall tube, which differs from [Example 1] in that: in the nucleating masterbatch, the ultra-high molecular weight polyethylene is replaced by the modified ultra-high molecular weight polyethylene prepared in [Preparation Example 2-4].

[0038] Comparative Example [Comparative Example 1] A flexible sealed self-locking polyethylene wound solid wall pipe, which differs from [Example 1] in that the metallocene polyethylene is replaced by ultra-high molecular weight polyethylene of equal mass.

[0039] [Comparative Example 2] A flexible sealed self-locking polyethylene wound solid wall pipe, which differs from [Example 1] in that the ultra-high molecular weight polyethylene is replaced by metallocene polyethylene of equal mass.

[0040] [Comparative Example 3] A flexible sealed self-locking polyethylene wound solid wall tube, which differs from [Example 1] in that: in the nucleating masterbatch, the ultra-high molecular weight polyethylene is replaced by the modified ultra-high molecular weight polyethylene prepared in [Preparation Example 2-5].

[0041] Performance testing Sample preparation: Flexible sealed self-locking polyethylene wrapped solid wall tubes with an outer diameter of 400 mm and a wall thickness of 12.3 mm were prepared using the raw materials prepared in each embodiment and comparative example. During the preparation of the flexible sealed self-locking polyethylene wrapped solid wall tubes, the process conditions remained consistent.

[0042] 1. Molding shrinkage: The shrinkage of the raw materials for preparing the flexible sealed self-locking polyethylene wound solid wall tube in the embodiments and comparative examples in the diameter direction was tested with reference to the standard GB / T 15585-1995 Determination of the shrinkage of thermoplastic injection molding, wherein each group of samples was tested 5 times in parallel and the shrinkage range was recorded.

[0043] 2. Wear resistance: Refer to the wear resistance test method QB / T 5101-2017 for plastic pipes for wear resistance test. The number of wear times is 5 million times, and the mass wear rate is recorded.

[0044] 3. Leakage test: After connecting three flexible sealed self-locking polyethylene wrapped solid wall pipes made in the same experimental group according to the same process, test the leakage performance of the pipe connection under the conditions of 20℃ and 12.0MPa for 100 hours to observe whether there is leakage. Among them, 10 samples are taken from each experimental group for testing, and those without leakage at each connection point are qualified.

[0045] 4. Wall thickness tolerance: 10 pipes prepared in each embodiment and comparative example were randomly selected, and 5 points were selected at equal intervals along the length direction of each pipe for wall thickness detection, and the wall thickness tolerance of each point was calculated, and the wall thickness tolerance range of each point in the 10 samples was recorded. Among them, the wall thickness tolerance of any point is less than or equal to 1.4mm to meet the requirements.

[0046] Among them, when the radial shrinkage rate and wall thickness tolerance are small and stable, the product quality is more stable and the assembly accuracy is higher.

[0047] Table 1

[0048] Combining Example 1 with Comparative Examples 1-2 and the test data recorded in Table 1, it can be seen that the metallocene polyethylene in the nucleation masterbatch used in Comparative Example 1 is replaced by an ultra-high molecular weight polyethylene of equal mass, but an excessive amount of ultra-high molecular weight polyethylene will cause the melt viscosity to be too high, making it difficult for the modified talcum powder in the nucleation masterbatch to be evenly dispersed, thereby causing the radial shrinkage rate of the flexible sealing self-locking polyethylene wrapped solid wall pipe to fluctuate greatly and the wall thickness tolerance to fluctuate greatly, resulting in poor connection accuracy of the pipe socket, and the pipe is prone to water leakage. The ultra-high molecular weight polyethylene in the nucleation masterbatch used in Comparative Example 2 is replaced by an equal amount of metallocene polyethylene, wherein, without adding ultra-high molecular weight polyethylene, the wear resistance of the pipe is reduced and the shrinkage rate is increased. At the same time, due to the difference in viscosity between metallocene polyethylene and high-density polyethylene, it is also easy to cause large fluctuations in shrinkage rate and large fluctuations in wall thickness tolerance between different pipes, and it is also easy to cause poor connection accuracy of the pipe socket, resulting in water leakage.

[0049] Combining Example 1 with Examples 3-6 and the test data recorded in Table 1, it can be seen that the product in which ultra-high molecular weight polyethylene is modified by using a specific ratio of side chain monoacrylate silicone oil and polyethylene glycol to improve the processing of the nucleating masterbatch and promote the uniform mixing of the various raw materials of the nucleating masterbatch. It can further reduce the wall thickness tolerance of the pipe while ensuring a low shrinkage rate of the pipe, which is beneficial to improving the wall thickness accuracy of the pipe, and will not significantly affect the wear resistance of the flexible sealing self-locking polyethylene wrapped solid wall pipe.

[0050] Combining Example 1 with Comparative Example 3 and the search data recorded in Table 1, it can be seen that after omitting polyethylene glycol in Comparative Example 3, the radial shrinkage fluctuation and wall thickness fluctuation of the pipe increase, which is not conducive to improving the connection accuracy of the pipe. At the same time, due to the decrease in wall thickness uniformity, the wear resistance of the pipe is also reduced.

[0051] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A flexible sealed self-locking polyethylene wound solid wall pipe, characterized in that: The raw materials for preparing the flexible sealed self-locking polyethylene wound solid wall pipe include 15-25wt% nucleating masterbatch and the balance high-density polyethylene. The nucleating masterbatch is obtained by melt-plasticizing and granulating 28-32wt% metallocene polyethylene, 18-22wt% ultra-high molecular weight polyethylene and 50wt% modified talcum powder. The modified talcum powder is obtained by uniformly mixing talcum powder, silane coupling agent, aluminate coupling agent, stearic acid and olefin wax in a weight ratio of 100: (0.8-1.2): (0.8-1.2): (1.5-2.5): (1.5-2.5).

2. The flexible sealed self-locking polyethylene wound solid wall pipe according to claim 1, characterized in that: The mesh number of the talcum powder is 600-800 mesh, and the diameter-to-thickness ratio is 10-20.

3. A flexible sealed self-locking polyethylene wound solid wall pipe according to claim 1 or 2, characterized in that: The preparation method of the modified talcum powder is as follows: The talc powder is heated and stirred, and when the temperature of the talc powder is raised to 80-85° C., a silane coupling agent and an aluminate coupling agent are added and stirred, and when the temperature of the talc powder is raised to 90-95° C., stearic acid is added and stirred, and when the temperature of the talc powder is raised to 100-105° C., olefin wax is added and stirred until uniformly dispersed to obtain modified talc powder.

4. The flexible sealed self-locking polyethylene wound solid wall pipe according to claim 1, characterized in that: The molecular weight of the metallocene polyethylene is 80,000-150,000.

5. The flexible sealed self-locking polyethylene wound solid wall pipe according to claim 1, characterized in that: The molecular weight of the ultra-high molecular weight polyethylene is 4 million to 5 million.

6. The flexible sealed self-locking polyethylene wound solid wall pipe according to claim 1, characterized in that: The ultra-high molecular weight polyethylene adopts modified ultra-high molecular weight polyethylene, and the raw materials for preparing the modified ultra-high molecular weight polyethylene include side chain monoacrylate silicone oil, polyethylene glycol, ultra-high molecular weight polyethylene and peroxidation initiator in a weight ratio of (8.2-9.6): (2-4): 100: (0.01-0.015).

7. The flexible sealed self-locking polyethylene wound solid wall pipe according to claim 6, characterized in that: The polyethylene glycol is at least one of PEG6000 and PEG8000.

8. The flexible sealed self-locking polyethylene wound solid wall pipe according to claim 6, characterized in that: The structural formula of the side chain monoacrylate silicone oil is as follows: ； The value of n is 45-50, and the value of m is 1.

9. A flexible sealed self-locking polyethylene wound solid wall pipe according to any one of claims 6 to 8, characterized in that: The preparation method of the modified ultra-high molecular weight polyethylene comprises the following steps: After polyethylene glycol and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C., side chain monoacrylate silicone oil and peroxidation initiator are added, and the temperature is maintained at 180-190° C. for grafting reaction to obtain modified ultra-high molecular weight polyethylene.

10. A method for preparing a flexible sealed self-locking polyethylene wound solid wall pipe as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1. After the modified talc and ultra-high molecular weight polyethylene are uniformly melted at 180-190° C., metallocene polyethylene is added, and the temperature is maintained at 180-190° C. for melting and plasticization, and then extruded and granulated to obtain a nucleating masterbatch; S2. Evenly mix the nucleating masterbatch and high-density polyethylene according to the ratio, feed them into the extruder, heat and melt the extruded billet at 180-190°C, wind the billet on a roller mold, cool it, and perform socket processing to obtain a flexible sealed self-locking polyethylene wound solid wall pipe.

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