Plastic alloy composite high-performance pipe and preparation method thereof

Abstract

The invention relates to the technical field of pipes, and discloses a plastic alloy composite high-performance pipe and a preparation method thereof.The pipe structurally comprises, from inside to outside, an inner pipe, an outer pipe, an outer pipe, an inner pipe and an outer pipe from inside to outside in sequence, the middle pipe comprises a metal layer close to the inner layer and at least one adhesive film layer far away from the inner layer; each layer of adhesive film material comprises at least one of maleic acid liver grafted polyethylene, polyethylene and maleic acid liver grafted-ethylene-vinyl acetate copolymer; and the outer pipe is a flame-retardant layer. According to the composite high-performance pipe, the compression strength of the pipe is higher than that of existing similar pipes and full-plastic pipes with the same wall thickness by 60-120%, the compression strength of the pipe is improved by 30-50% compared with that of the existing similar pipes and full-plastic pipes with the same wall thickness by dn25 * 3.1 mm, the bursting pressure of the pipe and polyolefin PE-RT and PP-R composite pipes is 12-15 MPa, the bursting pressure of the pipe and the PE-RT and PP-R composite pipes is 20-30 MPa, and the bursting pressure of the pipe and the PE-RT and PP-R composite pipes is 20-30 MPa. The bursting pressure reaches 20-32 MPa, the installation efficiency is improved by more than three times, the bursting pressure of the PE-RT and PP-R composite pipe is 10-13 MPa, and the bursting pressure of the composite pipe reaches 19-30 MPa.

Description

Technical Field

[0001] The invention relates to the technical field of pipes, in particular to a plastic alloy composite high-performance pipe and a preparation method thereof. Background Art

[0002] At present, with the rapid development of urban construction and the continuous improvement of the living environment, the demand for pipes such as drinking water pipes and thermal pipes is increasing. Traditional cement pipes, steel pipes, and ductile iron pipes are high-energy consumption products with high carbon emissions. In actual use, a large number of PP-R pipes, PE pipes, PVC-M pipes, PVC-UH pipes, PVC-O pipes and other pipes are used. Plastic pipes have many advantages such as light weight, high strength, good hygienic performance, convenient installation and maintenance, and corrosion resistance, but low strength and thick pipe walls. In order to improve the strength of pipes, most steel-plastic composite pipes are used, such as steel-lined plastic pipes, PP-R or PE steel-plastic composite pipes, steel wire mesh reinforced pipes, and steel skeleton reinforced pipes. These composite pipes are basically composited with polyolefin materials. Polyolefin materials have poor rigidity and poor pressure bearing effect. The strength cannot meet higher requirements, such as higher requirements for temperature and pressure. At the same time, polyolefin composite pipes cannot be bonded at room temperature, which is a great obstacle to replacement, maintenance and high-altitude operations. Summary of the invention

[0003] Technical problems solved by the present invention:

[0004] It is used to solve the problems of poor rigidity, poor pressure bearing effect, inability to bond and inconvenient installation of existing composite pipes.

[0005] The technical solution adopted by the present invention is:

[0006] In view of the above technical problems, the purpose of the present invention is to provide a plastic alloy composite high-performance pipe and a preparation method thereof. The specific contents are as follows:

[0007] First, the present application provides a plastic alloy composite high-performance pipe; its pipe structure includes at least three layers, from inside to outside:

[0008] The inner tube is a heat-melt weldable antibacterial layer, namely, a PE-RT antibacterial layer;

[0009] The intermediate tube comprises a metal layer close to the inner layer and at least one film layer far from the inner layer; each film layer comprises at least one of maleic acid grafted polyethylene, polyethylene, and maleic acid grafted-ethylene-vinyl acetate copolymer;

[0010] The outer tube is a flame retardant layer; the flame retardant material includes polyvinyl chloride and chlorinated polyvinyl chloride;

[0011] To further expand, the formula of each pipeline layer structure is as follows:

[0012] The inner tube comprises the following raw material components by weight: 100 parts of resin, 1-5 parts of masterbatch, 0.02-0.2 parts of diethyl propylene peroxide, 1.5-2.5 parts of vinyl trimethoxy silane, 0.1-0.3 parts of organic tin, 0.3-1.0 parts of antioxidant and 0.1-1.0 parts of antibacterial agent.

[0013] The resin includes at least one of PE, PE-RT, PP-R, and PB.

[0014] The antioxidant includes at least one of the antioxidant 1010 and the antioxidant 176 .

[0015] The antibacterial agent includes at least one of a silver ion antibacterial agent and a rare earth antibacterial agent.

[0016] The middle tube is made of maleic anhydride graft copolymer and three-layer adhesive film.

[0017] The outer tube comprises the following raw material components by weight: 70-100 parts of PVC / PVC-C, 70-100 parts of ABS, 5-15 parts of PC, 2-10 parts of stabilizer, 0.1-1 part of lubricant, 1-15 parts of modifier, 0.1-5 parts of pigment, 1-15 parts of compatibilizer and 1-15 parts of nano filler.

[0018] Among the aforementioned components:

[0019] The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, and a rare earth stabilizer.

[0020] The lubricant includes at least one of stearic acid, paraffin, polyethylene wax and oxidized polyethylene wax.

[0021] The modifier includes at least one of chlorinated polyethylene, MBS, ABS, ACR, nitrile rubber, and EVA.

[0022] The pigment includes at least one of titanium dioxide, ultramarine, carbon black, silicon dioxide, green toner, red toner, yellow toner, blue toner and purple toner.

[0023] The compatibilizer includes maleic anhydride grafted ethylene-vinyl acetate copolymer.

[0024] The nano filler includes at least one of calcium carbonate, quartz sand, barium sulfate, mica, titanium dioxide, silicon dioxide, and glass fiber.

[0025] Second, the present invention provides a method for preparing the aforementioned plastic alloy composite high-performance pipe, comprising the following steps:

[0026] Process route: inner tube extrusion (processing temperature 140℃-220℃) - cooling (20℃-36℃) - outer layer heating (120℃-150℃) - maleic acid liver graft copolymer compounded on the outer surface of the inner tube - metal pipe coated on the outside of the inner tube - three-layer film compounded on the surface of the metal pipe - heating (100-180℃) - outer plastic extrusion compounded on the three-layer film - cooling - the inner wall of the pipe is steam heated and cross-linked (that is, the pipe is placed on the rack, both ends are blocked, and 60℃-100℃ steam or hot water is input through the input hole, and the thermal cross-linking time is 1-4h) - cooling - testing - finished product.

[0027] The inner tube material is extruded to obtain the inner tube material, the intermediate material is heated and compounded on the outer surface of the inner tube, the metal tube is coated on the outer surface of the inner tube, and then the film is wrapped on the surface of the metal pipe; then, the outer layer material is extruded and compounded on the surface of the film, the inner wall is vacuum cross-linked and heated, and the tube is obtained after cooling.

[0028] In the above, the preparation method of the inner tube material is to weigh the inner tube material in proportion, stir it in a mixer for 3 to 15 minutes, the temperature does not exceed 40°C, and put the mixed inner tube material into an extruder for extrusion. The parameters of the extruder are: barrel temperature zone 1 130 to 140°C, zone 2 150 to 170°C, zone 3 170 to 180°C, zone 4 180 to 200°C, mold temperature 185 to 200°C, die temperature 190 to 235°C; extrusion speed 1 to 3 m / min.

[0029] In the above, the preparation method of the film is to use a three-layer extrusion die, 3 extruders, the inner film is maleic acid grafted polyethylene, the middle film is polyethylene, and the outer film is maleic acid grafted-ethylene-vinyl acetate copolymer. The processing temperature of the film is 140-190°C. After the composite film is extruded, the cooling coil is a three-layer film. In the above, if a commonly used hot melt adhesive is directly used, the adhesive strength between PVC and metal pipes will be insufficient; based on this, we use a three-layer film to overcome the above problems, specifically: the three-layer film is divided into an outer film, a transition film, and an inner film. The outer film is bonded to the PVC alloy material, the inner film is bonded to the metal, and the middle film is between the inner and outer films of the above film. If only the traditional hot melt adhesive is used to obtain the film, its bonding effect will be very poor, that is, there is a poor bonding effect with the metal, or a poor bonding effect with the PVC alloy material, or a good bonding effect with the PVC alloy material, and a poor bonding effect with the metal. Based on this, we set up three layers of adhesive film to meet the purpose of bonding with PVC alloy material and metal steel strip at the same time. In the present invention, the three layers of adhesive film are wound on the surface of the inner pipe by winding, and the winding speed is synchronized with the pipe extrusion speed.

[0030] In the above, the preparation process of the outer tube is to weigh the outer layer material in proportion, put it into a high-speed mixer and stir it for 3 to 15 minutes at a temperature of 110°C, cool the mixed material to 35°C, bag it for standby use, and put the standby material into the equipment mold that meets the following conditions for extrusion molding. Outer tube process: extruder barrel temperature zone 1 175 ~ 225°C, zone 2 165 ~ 215°C, zone 3 165 ~ 180°C, zone 4 155 ~ 175°C, mold temperature 175 ~ 200°C, die temperature 175 ~ 215°C, extrusion speed 1 ~ 3 meters / min.

[0031] In the above, the process of cross-linking the inner tube is as follows: the steam temperature is 60-100°C and the heating time is 1-4h.

[0032] In addition, the present invention can also change the inner tube material to the same material as the outer layer according to the above process, but the processing technology needs to be adjusted in the same way as the outer process.

[0033] The beneficial effects achieved by the present invention are:

[0034] Through the above invention, the compressive strength of the pipe is 60-120% higher than that of the existing similar pipes, and the compressive strength of the all-plastic dn25x3.1mm pipes with the same wall thickness is increased by 30-50%. The bursting pressure of polyolefin PE-RT and PP-R composite pipes is 12-15MPa, and the bursting pressure of the present invention reaches 20-32MPa; for dn32x3.3mm, the bursting pressure of PE-RT and PP-R composite pipes is 10-13MPa, and the bursting pressure of the present invention reaches 19-30MPa. At the same time, the installation efficiency of the pipe provided by the present invention is increased by more than 3 times. In addition, the heat-resistant polyethylene of the inner layer pipe of the present invention is heat-resistant itself, and the heat resistance of the pipe is improved by cross-linking. The present invention can also use PVC or PVC-C plastic alloy materials and metal steel belts for both the inner layer pipe and the outer layer pipe.

[0035] The inner layer pipe of the present invention adopts polyolefin, which is mainly convenient for production and processing, and cross-linking improves heat resistance. At the same time, when the metal steel belt is composited, the inner layer pipe needs to be heated, so the inner layer pipe is required to be a heat-resistant material, and it can also meet the requirements of common hot and cold water pipes. The middle composite steel belt mainly blocks oxygen, improves strength, and prevents bending and deformation. The outer layer adopts PVC or PVC-C alloy, which on the one hand improves the strength of the pipe, and on the other hand can be glued to the pipe fittings at room temperature, and the installation is fast and efficient, which is very convenient. At the same time, PVC and PVC-C alloy are very resistant to aging materials, have a longer service life, and good flame retardant properties. They have obvious advantages in fire protection pipes. If polyolefins are to achieve this flame retardant property, a lot of flame retardant materials need to be added, the brittleness of the pipe increases, the strength decreases greatly, and the service life is shortened.

[0036] The outer layer plastic of the present invention is PC, ABS, and PVC, and its comprehensive tensile strength is 2.5 to 4 times that of polyolefins, and its compressive strength is 2 times that of polyolefins; the heat resistance is improved after the inner layer is cross-linked, and the pressure-bearing performance of the pipe is better at high temperatures. Coupled with the metal reinforcement properties, the overall composite pipe performance is greatly improved, the weight of the pipe is reduced, and the strength is better, achieving energy conservation and emission reduction, low-carbon environmental protection effects, and also solving the problem of poor flame retardant effect of polyolefins.

[0037] The pipeline provided by the present invention can be used in the fields of natural gas transmission, fire protection pipeline, hot and cold water pipeline, drainage of high-rise buildings above 100 meters, etc. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0039] Example 1

[0040] This embodiment provides a method for preparing a plastic alloy composite high-performance pipe, comprising the following steps:

[0041] (1) Weigh the inner tube material and outer tube material by weight. Inner tube material: 100 parts of PE-RT, 3 parts of masterbatch, 0.1 parts of diethyl propylene peroxide, 2 parts of vinyl trimethoxysilane, 0.2 parts of organic tin, 0.5 parts of antioxidant 1010, and 0.5 parts of silver ion antibacterial agent. Outer tube material: 90 parts of PVC-C, 90 parts of ABS, 10 parts of PC, 8 parts of calcium zinc stabilizer, 0.5 parts of polyethylene wax, 10 parts of ABS, 3 parts of titanium dioxide, 10 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer, and 10 parts of calcium carbonate.

[0042] (2) Pipe preparation: The processing technology of pipes is as follows:

[0043] Inner tube extrusion (processing temperature 140℃-220℃) - cooling (20℃-36℃) - outer layer heating (120℃-150℃) - maleic acid liver grafted copolymer on the outer surface of the inner tube - metal pipe coated on the outside of the inner tube - three layers of film composited on the surface of the metal pipe - heating (100-180℃) - outer layer plastic extrusion composite three layers of film - cooling - the inner wall of the pipe is steam heated and cross-linked (that is, the pipe is placed on the rack, both ends are blocked, and 60℃-100℃ steam or hot water is input through the input hole, and the thermal cross-linking time is 1-4h) - cooling - testing - finished product.

[0044] The inner tube material is extruded to obtain the inner tube material, the intermediate material is heated and compounded on the outer surface of the inner tube, the metal tube is coated on the outer surface of the inner tube, and then the film is wrapped on the surface of the metal pipe; then, the outer layer material is extruded and compounded on the surface of the film, the inner wall is vacuum cross-linked and heated, and the tube is obtained after cooling.

[0045] The preparation method of the inner tube material is as follows: weigh the inner tube material in proportion, stir it in a mixer for 3 to 15 minutes, the temperature does not exceed 40°C, and put the mixed inner tube material into an extruder for extrusion. The parameters of the extruder are: barrel temperature zone 1 130 to 140°C, zone 2 150 to 170°C, zone 3 170 to 180°C, zone 4 180 to 200°C, mold temperature 185 to 200°C, die temperature 190 to 235°C; extrusion speed 1 to 3 m / min.

[0046] The preparation method of the film is to use a three-layer extrusion die and three extruders, the inner film is maleic acid grafted polyethylene, the middle film is polyethylene, and the outer film is maleic acid grafted ethylene-vinyl acetate copolymer. The processing temperature of the film is 140-190°C, and after extruding the composite film, it is cooled and rolled into a three-layer film.

[0047] The preparation process of the outer tube is to weigh the outer layer material in proportion, put it into a high-speed mixer and stir it for 3 to 15 minutes at a temperature of 110°C, cool the mixed material to 35°C, bag it for standby use, and put the standby material into the equipment mold that meets the following conditions for extrusion molding. Outer tube process: extruder barrel temperature zone 1 175 ~ 225°C, zone 2 165 ~ 215°C, zone 3 165 ~ 180°C, zone 4 155 ~ 175°C, mold temperature 175 ~ 200°C, die temperature 175 ~ 215°C, extrusion speed 1 ~ 3 meters / min.

[0048] In the above, the process of cross-linking the inner tube is as follows: the steam temperature is 60-100°C and the heating time is 1-4h.

[0049] After testing: the compressive strength of the same wall thickness of all-plastic dn25 x3.1mm pipes increased by 60-120%, and the hot water pipes increased by 30-50%. The bursting pressure of polyolefin PE-RT and PP-R composite pipes is 12-15MPa, and the bursting pressure of the pipes in this embodiment reaches 20-32MPa; for dn32x3.3mm, the bursting pressure of PE-RT and PP-R composite pipes is 10-13MPa, and the bursting pressure of the pipes in this embodiment reaches 19-30MPa. At the same time, the installation efficiency of the pipes is increased by more than 3 times.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plastic alloy composite high-performance pipe, characterized in that: The pipeline structure from inside to outside is: An inner tube, which is an antibacterial material capable of being heat-melted and welded; The intermediate tube comprises a metal layer close to the inner layer and at least one film layer far from the inner layer; each film layer comprises at least one of maleic acid grafted polyethylene, polyethylene, and maleic acid grafted-ethylene-vinyl acetate copolymer; The outer tube is a flame retardant layer.

2. The plastic alloy composite high-performance pipe according to claim 1, characterized in that: The raw material components of the inner tube material include, by weight, 100 parts of resin, 1-5 parts of masterbatch, 0.02-0.2 parts of diethyl propylene peroxide, 1.5-2.5 parts of vinyl trimethoxy silane, 0.1-0.3 parts of organic tin, 0.3-1.0 parts of antioxidant, and 0.1-1.0 parts of antibacterial agent.

3. The plastic alloy composite high-performance pipe according to claim 2, characterized in that: The resin includes at least one of PE, PE-RT, PP-R, and PB; and / or the antioxidant includes at least one of antioxidant 1010 and antioxidant 176; and / or the antibacterial agent includes at least one of silver ion antibacterial agent and rare earth antibacterial agent.

4. The plastic alloy composite high-performance pipe according to claim 1, characterized in that: The raw material components of the outer tube material include 70-100 parts of PVC / PVC-C, 70-100 parts of ABS, 5-15 parts of PC, 2-10 parts of stabilizer, 0.1-1 part of lubricant, 1-15 parts of modifier, 0.1-5 parts of pigment, 1-15 parts of compatibilizer and 1-15 parts of nano filler, by weight.

5. The plastic alloy composite high-performance pipe according to claim 4, characterized in that: The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, and a rare earth stabilizer; and / or the lubricant includes at least one of stearic acid, paraffin, polyethylene wax, and oxidized polyethylene wax; and / or the modifier includes at least one of chlorinated polyethylene, MBS, ABS, ACR, nitrile rubber, and EVA; and / or the pigment includes at least one of titanium dioxide, ultramarine, carbon black, silica, green toner, red toner, yellow toner, blue toner, and purple toner; and / or the compatibilizer includes maleic anhydride grafted ethylene-vinyl acetate copolymer; and / or the nanofiller includes at least one of calcium carbonate, quartz sand, barium sulfate, mica, titanium dioxide, silica, and glass fiber.

6. The method for preparing the plastic alloy composite high-performance pipe according to any one of claims 1 to 5, characterized in that: The steps include: The inner tube material is extruded to obtain the inner tube, the intermediate material is heated and compounded on the outer surface of the inner tube, the metal tube is coated on the outer surface of the inner tube, and then the film is wrapped on the surface of the metal tube; then, the outer tube material is extruded and compounded on the surface of the film, the inner wall is vacuum cross-linked and heated, and the tube is obtained after cooling.

7. The method for preparing the plastic alloy composite high-performance pipe according to claim 6, characterized in that: The preparation method of the inner tube is as follows: weigh the inner tube material according to proportion, stir it in a mixer for 3 to 15 minutes at a temperature not exceeding 40° C., and put the mixed inner tube material into an extruder for extrusion.

8. The method for preparing the plastic alloy composite high-performance pipe according to claim 7, characterized in that: The parameters of the extruder are: barrel temperature zone 1 130-140°C, zone 2 150-170°C, zone 3 170-180°C, zone 4 180-200°C, mold temperature 185-200°C, die temperature 190-235°C; extrusion speed 1-3 m / min.

9. The method for preparing the plastic alloy composite high-performance pipe according to claim 6, characterized in that: The preparation method of the film is to extrude the film using three extruders to obtain a composite film; the processing temperature of the film is 140-190°C; and / or the film has a three-layer structure, the inner film is maleic acid grafted polyethylene, the middle film is polyethylene, and the outer film is maleic acid grafted-ethylene-vinyl acetate copolymer.

10. The method for preparing the plastic alloy composite high-performance pipe according to claim 6, characterized in that: The preparation method of the outer tube is as follows: the temperature is 110°C, the mixed materials are cooled to 35°C, bagged for standby use, and extruded; the barrel temperature of the extruder is 175-225°C in zone 1, 165-215°C in zone 2, 165-180°C in zone 3, 155-175°C in zone 4, the mold temperature is 175-200°C, the die temperature is 175-215°C, and the extrusion speed is 1-3 m / min.