High-strength polyethylene water supply pipe and method for manufacturing the same

Abstract

The application relates to the technical field of high polymer materials, and discloses a high-strength polyethylene water supply pipe and a preparation method thereof. The high-strength polyethylene water supply pipe comprises, from inside to outside, a pipe body, a polypropylene reinforcing pipe and an outer cladding belt; the pipe body is composed of an inner layer, a core layer and an outer layer, and the inner layer and the outer layer are both made of polyethylene material; the polyethylene material comprises the following raw materials in parts by weight: 80-100 parts of high-density polyethylene, 10-15 parts of ethylene-ethyl acrylate copolymer, 5-8 parts of a reinforcing agent, 3-5 parts of a compatilizer, 1-2 parts of an antioxidant and 0.5-1 part of a dispersing agent; the reinforcing agent comprises the following raw materials in parts by weight: 100 parts of magnesium hydroxide whiskers, 1-4 parts of an alkenyl-containing silane coupling agent and 2-5 parts of styrene. Through the technical scheme, the problem of low strength of the polyethylene water supply pipe in the related art is solved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-strength polyethylene water supply pipe and its preparation method. Background Technology

[0002] As a crucial component of urban infrastructure and water supply and drainage systems in various buildings, water supply pipes directly affect the stability and safety of water supply. In modern society, both the daily water needs of urban residents and the large water demands of industrial production rely on efficient and reliable water supply pipeline networks. Currently, a wide variety of materials are used in the manufacture of water supply pipes, including metallic materials, inorganic non-metallic materials, and organic polymer materials. Among these materials, polyethylene is the most widely used due to its series of significant advantages. Polyethylene has good chemical stability and excellent processing performance, and its relatively low cost makes it widely used in the field of water supply pipes.

[0003] In actual service, water supply pipes need to withstand complex loads such as system water pressure and external impacts for a long time. However, the mechanical strength of existing polyethylene water supply pipes is not yet sufficient to meet the requirements of this working condition. As the service time increases, the water supply pipes will experience fatigue wear, and their load-bearing capacity will show a continuous decline trend, which can easily lead to problems such as water supply pipe leakage and damage.

[0004] Therefore, it is necessary to propose a high-strength polyethylene water supply pipe and its preparation method to improve the mechanical strength of the water supply pipe and ensure the safe and stable operation of the water supply system. Summary of the Invention

[0005] This invention proposes a high-strength polyethylene water supply pipe and its preparation method, which solves the problem of low mechanical strength of polyethylene water supply pipes in related technologies.

[0006] The technical solution of the present invention is as follows:

[0007] A high-strength polyethylene water supply pipe comprises, from the inside out, a pipe body, a polypropylene reinforced pipe, and an outer covering tape; the pipe body is composed of an inner layer, a core layer, and an outer layer, wherein the inner and outer layers are both made of polyethylene material, and the core layer is made of fiberglass cloth;

[0008] The polyethylene material comprises the following raw materials in parts by weight: 80-100 parts of high-density polyethylene, 10-15 parts of ethylene-ethyl acrylate copolymer, 5-8 parts of reinforcing agent, 3-5 parts of compatibilizer, 1-2 parts of antioxidant, and 0.5-1 part of dispersant.

[0009] The reinforcing agent comprises the following raw materials in parts by weight: 100 parts magnesium hydroxide whiskers, 1-4 parts alkenyl-containing silane coupling agent, and 2-5 parts styrene.

[0010] As a further technical solution, the reinforcing agent also includes the following raw materials in parts by weight: 1-2 parts of N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane.

[0011] Magnesium hydroxide whiskers have poor compatibility with the polyethylene matrix, resulting in their inability to fully exert their reinforcing effect. The N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane in the reinforcing agent of this invention can form hydrogen bonds with the carbonyl groups in the ethylene-ethyl acrylate copolymer, thereby improving the compatibility of the reinforcing agent with the polyethylene material and thus enhancing the mechanical strength of the polyethylene water supply pipe.

[0012] As a further technical solution, the alkenyl-containing silane coupling agent includes silane coupling agent A-171.

[0013] As a further technical solution, the preparation method of the reinforcing agent includes the following steps:

[0014] A1. Magnesium hydroxide whiskers are activated and then mixed with N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane, an alkenyl-containing silane coupling agent and a solvent, and dried to obtain silane-modified magnesium hydroxide whiskers.

[0015] A2. A reinforcing agent is obtained by mixing silane-modified magnesium hydroxide whiskers, styrene, and an initiator.

[0016] As a further technical solution, the mass ratio of magnesium hydroxide whiskers to styrene is 100:2~5, preferably 100:3.

[0017] As a further technical solution, in step A1, the mass-to-volume ratio of the magnesium hydroxide whiskers to the solvent is 1g:8mL.

[0018] As a further technical solution, in step A1, the solvent is anhydrous ethanol.

[0019] As a further technical solution, in step A1, the activation treatment involves heating magnesium hydroxide whiskers to 65-75°C at a rotation speed of 1100-1300 rpm.

[0020] As a further technical solution, in step A1, the mixing temperature is 45~55℃ and the time is 2~4h.

[0021] As a further technical solution, in step A2, the mixing is carried out at a rotation speed of 1100~1300 rpm and a temperature of 70~85℃ for 40~50 minutes.

[0022] As a further technical solution, in step A2, the mass ratio of styrene to initiator is 60:1.

[0023] As a further technical solution, the initiator is azobisisobutyronitrile.

[0024] As a further technical solution, the ethylene-ethyl acrylate copolymer includes a first ethylene-ethyl acrylate copolymer and a second ethylene-ethyl acrylate copolymer. The melt index of the first ethylene-ethyl acrylate copolymer is 1.3 g / 10 min, and the test conditions are 190°C and 2.16 kg. The melt index of the second ethylene-ethyl acrylate copolymer is 3.5 g / 10 min, and the test conditions are 190°C and 2.16 kg.

[0025] Through experiments, the inventors discovered that adding two ethylene-ethyl acrylate copolymers with different melt indices to polyethylene materials can further improve their corrosion resistance. The first ethylene-ethyl acrylate copolymer has a low melt index and long molecular chains, forming a continuous and dense network structure that effectively blocks the penetration and diffusion of corrosive media such as acids, alkalis, and salt solutions. However, the long molecular chains result in weak melt flowability, making it prone to uneven dispersion and the formation of micro-voids within the material during processing. The second ethylene-ethyl acrylate copolymer, on the other hand, possesses a high melt index and excellent molecular chain flowability. During processing, it can fill the micro-voids left by the first ethylene-ethyl acrylate copolymer, further blocking the penetration path of corrosive media. Simultaneously, it avoids the problem of reduced material strength that might result from an excessively high melt index. The synergistic effect of these two copolymers further enhances the corrosion resistance of the polyethylene material.

[0026] As a further technical solution, the mass ratio of the first ethylene-ethyl acrylate copolymer to the second ethylene-ethyl acrylate copolymer is 3~5:2.

[0027] As a further technical solution, the compatibilizer includes one or both of maleic anhydride-grafted polyethylene and maleic anhydride-grafted ethylene-octene copolymer.

[0028] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 1076, and antioxidant 168.

[0029] As a further technical solution, the dispersant includes one or two of calcium stearate and polyethylene wax.

[0030] This invention also proposes a method for preparing a high-strength polyethylene water supply pipe, comprising the following steps:

[0031] S1. Extruding the inner layer material to form the inner layer;

[0032] S2. Adhere and wrap the fiberglass cloth to the outer side of the inner layer to form the core layer;

[0033] S3. Extrude the outer layer material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0034] S4. The polypropylene reinforced pipe and the outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0035] As a further technical solution, the outer covering tape is a polyethylene outer covering tape.

[0036] As a further technical solution, the bonding is hot air bonding. During hot air bonding, the temperature of the hot air is 280~320℃, the angle between the hot air and the fiberglass cloth is 40~50°, and the distance between the hot air outlet and the fiberglass cloth is 45~55mm.

[0037] As a further technical solution, during the hot air bonding process, a pressure roller is used to apply radial pressure to the glass fiber cloth, and the radial pressure is 0.2~0.4MPa.

[0038] The working principle and beneficial effects of this invention are as follows:

[0039] This invention discloses a high-strength polyethylene water supply pipe and its preparation method. A reinforcing agent is added to the polyethylene material to further enhance the mechanical strength of the water supply pipe. Magnesium hydroxide whiskers can improve the strength of polyethylene material, but these whiskers are prone to entanglement and aggregation, making uniform dispersion in the matrix difficult. The reinforcing agent prepared in this invention can improve the poor dispersibility of magnesium hydroxide whiskers by working together with polystyrene through an alkenyl-containing silane coupling agent, thereby enhancing the mechanical strength of the polyethylene water supply pipe. Detailed Implementation

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] In the following examples and comparative examples, high-density polyethylene, product number DMDA8008H, was purchased from Shanghai Xinsufa New Material Co., Ltd.; the first ethylene-ethyl acrylate copolymer, model EA100, with a melt index of 1.3 g / 10 min (test conditions 190℃, 2.16 kg), was purchased from Shanghai Kaiyin Chemical Co., Ltd.; the second ethylene-ethyl acrylate copolymer, model E403, with a melt index of 3.5 g / 10 min (test conditions 190℃, 2.16 kg), was purchased from Shanghai Kaiyin Chemical Co., Ltd.; the ethylene-ethyl acrylate copolymer, model... E101, melt index 6.0 g / 10 min (test conditions 190℃, 2.16 kg), purchased from Shanghai Kaiyin Chemical Co., Ltd.; glass fiber cloth, purchased from Taizhou Zhong Sheng Glass Fiber Products Co., Ltd.; maleic anhydride grafted polyethylene, grade SL-12, purchased from Dongguan Shengli New Materials Co., Ltd.; maleic anhydride grafted ethylene-octene copolymer, grade GR-209, purchased from Shenzhen Wansuyuan Rubber & Plastics Co., Ltd.; polyethylene wax, grade CJ-95, purchased from Linyi Chengju Chemical Co., Ltd.; magnesium hydroxide whiskers, diameter 3 μm, length 100 μm.

[0042] Example 1

[0043] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0044] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0045] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0046] The preparation method of the reinforcing agent includes the following steps:

[0047] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0048] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0049] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0050] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0051] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0052] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0053] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0054] Example 2

[0055] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0056] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0057] The polyethylene material comprises the following raw materials in parts by weight: 90 parts high-density polyethylene, 13 parts ethylene-ethyl acrylate copolymer, 6 parts reinforcing agent, 4 parts maleic anhydride-grafted ethylene-octene copolymer, 1.5 parts antioxidant 1076, and 0.8 parts polyethylene wax; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0058] The preparation method of the reinforcing agent includes the following steps:

[0059] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 2 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0060] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0061] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0062] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0063] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0064] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0065] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0066] Example 3

[0067] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0068] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0069] The polyethylene material comprises the following raw materials in parts by weight: 100 parts high-density polyethylene, 15 parts ethylene-ethyl acrylate copolymer, 8 parts reinforcing agent, 5 parts maleic anhydride-grafted ethylene-octene copolymer, 2 parts antioxidant 168, and 1 part polyethylene wax; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0070] The preparation method of the reinforcing agent includes the following steps:

[0071] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 1 part of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0072] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0073] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0074] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0075] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0076] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0077] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0078] Example 4

[0079] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0080] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0081] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0082] The preparation method of the reinforcing agent includes the following steps:

[0083] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then, mix with 1 part of N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane, 3 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours, and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-to-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0084] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0085] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0086] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0087] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0088] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0089] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0090] Example 5

[0091] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0092] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0093] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0094] The preparation method of the reinforcing agent includes the following steps:

[0095] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then, mix with 2 parts of N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane, 2 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours, and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-to-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0096] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0097] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0098] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0099] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0100] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0101] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0102] Example 6

[0103] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0104] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0105] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is composed of a first ethylene-ethyl acrylate copolymer (model EA100) and a second ethylene-ethyl acrylate copolymer (model E403) in a mass ratio of 3:2.

[0106] The preparation method of the reinforcing agent includes the following steps:

[0107] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0108] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0109] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0110] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0111] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0112] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0113] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0114] Example 7

[0115] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0116] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0117] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is composed of a first ethylene-ethyl acrylate copolymer (model EA100) and a second ethylene-ethyl acrylate copolymer (model E403) in a mass ratio of 2:1.

[0118] The preparation method of the reinforcing agent includes the following steps:

[0119] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0120] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0121] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0122] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0123] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0124] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0125] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0126] Example 8

[0127] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0128] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0129] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is composed of a first ethylene-ethyl acrylate copolymer (model EA100) and a second ethylene-ethyl acrylate copolymer (model E403) in a mass ratio of 5:2.

[0130] The preparation method of the reinforcing agent includes the following steps:

[0131] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0132] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0133] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0134] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0135] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0136] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0137] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0138] Example 9

[0139] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0140] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0141] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is a second ethylene-ethyl acrylate copolymer (model E403).

[0142] The preparation method of the reinforcing agent includes the following steps:

[0143] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0144] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0145] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0146] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0147] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0148] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0149] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0150] Example 10

[0151] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0152] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0153] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts reinforcing agent, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein, the ethylene-ethyl acrylate copolymer is composed of a first ethylene-ethyl acrylate copolymer (model EA100) and an ethylene-ethyl acrylate copolymer of model E101 in a mass ratio of 3:2;

[0154] The preparation method of the reinforcing agent includes the following steps:

[0155] A1. Place 100 parts of magnesium hydroxide whiskers in a mixer and heat to 70°C at 1200 rpm to complete the activation treatment. Then mix with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dry to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0156] A2. Place silane-modified magnesium hydroxide whiskers in a mixer, then add styrene and azobisisobutyronitrile (AIBN). Mix for 45 minutes at 1200 rpm and 80°C to obtain the reinforcing agent. The mass ratio of magnesium hydroxide whiskers to styrene is 100:3; the mass ratio of styrene to AIBN is 60:1.

[0157] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0158] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0159] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0160] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0161] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0162] Comparative Example 1

[0163] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0164] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0165] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts silane-modified magnesium hydroxide whiskers, 3 parts maleic anhydride-grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0166] The preparation method of silane-modified magnesium hydroxide whiskers includes the following steps: 100 parts of magnesium hydroxide whiskers are placed in a mixer and heated to 70°C at a speed of 1200 rpm to complete the activation treatment. Then, they are mixed with 4 parts of silane coupling agent A-171 and anhydrous ethanol at 50°C for 3 hours and dried to obtain silane-modified magnesium hydroxide whiskers. The mass-volume ratio of magnesium hydroxide whiskers to anhydrous ethanol is 1 g: 8 mL.

[0167] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0168] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0169] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0170] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0171] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0172] Comparative Example 2

[0173] A high-strength polyethylene water supply pipe, comprising, from the inside out, a pipe body, a polypropylene reinforcing pipe, and a polyethylene outer covering tape;

[0174] The tube body is composed of an inner layer, a core layer, and an outer layer. The inner and outer layers are made of polyethylene, and the core layer is made of fiberglass cloth.

[0175] The polyethylene material comprises the following raw materials in parts by weight: 80 parts high-density polyethylene, 10 parts ethylene-ethyl acrylate copolymer, 5 parts magnesium hydroxide whiskers, 3 parts maleic anhydride grafted polyethylene, 1 part antioxidant 1010, and 0.5 parts calcium stearate; wherein the ethylene-ethyl acrylate copolymer is the first ethylene-ethyl acrylate copolymer (model EA100).

[0176] A method for preparing a high-strength polyethylene water supply pipe includes the following steps:

[0177] S1. The inner layer of polyethylene material is extruded and molded to form the inner layer;

[0178] S2. Wrap the fiberglass cloth around the outer side of the inner layer. While wrapping, apply radial pressure to the fiberglass cloth using a pressure roller and hot air bonding to form the core layer. The hot air temperature during hot air bonding is 300℃, the angle between the hot air and the fiberglass cloth is 45°, the radial pressure is 0.3MPa, and the distance between the hot air outlet and the fiberglass cloth is 50mm.

[0179] S3. Extrude the outer layer of polyethylene material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body;

[0180] S4. The polypropylene reinforced pipe and the polyethylene outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

[0181] The inner layers of the high-strength polyethylene water supply pipes prepared in Examples 1-10 and Comparative Examples 1-2 were tested according to the following method:

[0182] 1. Impact strength: The impact strength of the specimen was tested using an impact testing machine according to the test method specified in GB / T 1043.1-2008 "Determination of impact properties of simply supported plastic beams - Part 1: Non-instrumental impact test". The specimen size was 80mm×10mm×4.0mm and the bottom radius of the notch was 1.0mm.

[0183] 2. Bending strength and corrosion resistance: The bending properties of the specimens were tested using a bending testing machine according to the test methods specified in GB / T 9341-2008 "Determination of Bending Properties of Plastics". The specimens were treated at 25℃ for 120 hours with 98% concentrated sulfuric acid, and then the bending strength of the treated specimens was tested. The specimen size was 80mm×10mm×4.0mm, and the test speed was 2mm / min.

[0184] The test results are shown in Tables 1 and 2:

[0185] Table 1. Test results of impact strength and bending strength of the inner layer of polyethylene water supply pipes.

[0186]

[0187] As shown in Table 1, the comparison between Examples 1-5 and Comparative Examples 1-2 indicates that the addition of reinforcing agents can improve the impact strength and bending strength of the inner layer of the polyethylene water supply pipe, thereby enhancing the overall mechanical strength of the polyethylene water supply pipe.

[0188] Table 2. Test results of corrosion resistance of the inner layer of polyethylene water supply pipes.

[0189]

[0190] As shown in Table 2, the comparison of Examples 1, 6-10 indicates that when the ethylene-ethyl acrylate copolymer is composed of the first ethylene-ethyl acrylate copolymer (melt index of 1.3 g / 10 min, test conditions 190℃, 2.16 kg) and the second ethylene-ethyl acrylate copolymer (3.5 g / 10 min, test conditions 190℃, 2.16 kg), the acid corrosion resistance of the inner layer of the polyethylene water supply pipe can be improved, thereby enhancing the overall corrosion resistance of the polyethylene water supply pipe.

[0191] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength polyethylene water supply pipe, characterized in that, From the inside out, it includes a tube body, a polypropylene reinforced tube, and an outer covering tape; the tube body is composed of an inner layer, a core layer, and an outer layer, the inner and outer layers are both made of polyethylene material, and the core layer is made of glass fiber cloth; The polyethylene material comprises the following raw materials in parts by weight: 80-100 parts of high-density polyethylene, 10-15 parts of ethylene-ethyl acrylate copolymer, 5-8 parts of reinforcing agent, 3-5 parts of compatibilizer, 1-2 parts of antioxidant, and 0.5-1 part of dispersant. The reinforcing agent comprises the following raw materials in parts by weight: 100 parts magnesium hydroxide whiskers, 1-4 parts alkenyl-containing silane coupling agent, and 2-5 parts styrene. The ethylene-ethyl acrylate copolymer comprises a first ethylene-ethyl acrylate copolymer and a second ethylene-ethyl acrylate copolymer in a mass ratio of 3~5:

2. The melt index of the first ethylene-ethyl acrylate copolymer is 1.3 g / 10 min, and the test conditions are 190℃ and 2.16 kg. The melt index of the second ethylene-ethyl acrylate copolymer is 3.5 g / 10 min, and the test conditions are 190℃ and 2.16 kg.

2. The high-strength polyethylene water supply pipe according to claim 1, characterized in that, The reinforcing agent also includes the following raw materials in parts by weight: 1-2 parts of N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane.

3. A high-strength polyethylene water supply pipe according to claim 1, characterized in that, The alkenyl-containing silane coupling agent includes silane coupling agent A-171.

4. A high-strength polyethylene water supply pipe according to claim 2, characterized in that, The method for preparing the reinforcing agent includes the following steps: A1. Magnesium hydroxide whiskers are activated and then mixed with N-(hydroxyethyl)-N-methylaminopropyltrimethoxysilane, an alkenyl-containing silane coupling agent and a solvent, and dried to obtain silane-modified magnesium hydroxide whiskers. A2. A reinforcing agent is obtained by mixing silane-modified magnesium hydroxide whiskers, styrene, and an initiator.

5. A high-strength polyethylene water supply pipe according to claim 4, characterized in that, In step A1, the activation treatment involves heating magnesium hydroxide whiskers to 65-75°C at a rotation speed of 1100-1300 rpm.

6. A high-strength polyethylene water supply pipe according to claim 4, characterized in that, In step A2, the mixing is carried out at a speed of 1100~1300 rpm and a temperature of 70~85℃ for 40~50 minutes.

7. A method for preparing a high-strength polyethylene water supply pipe, used to prepare a high-strength polyethylene water supply pipe as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Extruding the inner layer material to form the inner layer; S2. Adhere and wrap the fiberglass cloth to the outer side of the inner layer to form the core layer; S3. Extrude the outer layer material to cover the outside of the core layer to form the outer layer, thus obtaining the tube body; S4. The polypropylene reinforced pipe and the outer covering tape are wrapped around the outside of the pipe body in sequence to obtain a high-strength polyethylene water supply pipe.

8. The method for preparing a high-strength polyethylene water supply pipe according to claim 7, characterized in that, In step S2, the bonding is hot air bonding. During hot air bonding, the temperature of the hot air is 280~320℃, the angle between the hot air and the fiberglass cloth is 40~50°, and the distance between the hot air outlet and the fiberglass cloth is 45~55mm.

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