PVC drain pipe material and preparation method thereof

Abstract

The application discloses PVC drainage pipe material and a preparation method thereof, and belongs to the technical field of plastic pipe material. The raw materials of the PVC drainage pipe material include 90-100 parts of PVC resin, 10-20 parts of filler, 2-5 parts of heat stabilizer, 1-4 parts of chlorinated polyethylene, 1-3 parts of coupling agent, 2-4 parts of anti-aging agent, 1-1.5 parts of lubricant and 0.01-0.1 part of initiator. The anti-aging agent, the filler and the PVC resin form a crosslinked hybrid network structure, so that the filler and the anti-aging agent can be highly dispersed and stably exist in the PVC drainage pipe material, are not easy to migrate and be released, and continuously and stably play the roles of enhancing the mechanical properties, the oxidation resistance and the light stability of the PVC drainage pipe material. The anti-aging agent is different from the small molecule anti-oxidant on the market, is better compatible with the PVC resin, is more not easy to migrate and be released, and can fully play the oxidation resistance and the light stability.

Description

Technical Field

[0001] This invention belongs to the field of plastic pipe technology, specifically, it relates to a PVC drainage pipe and its preparation method. Background Technology

[0002] As an indispensable part of modern buildings, drainage systems directly impact the quality of life for residents. In recent years, with the acceleration of urbanization, the demand for efficient drainage systems has been increasing. PVC (polyvinyl chloride) materials, with their excellent chemical stability, lightweight durability, and low cost, have gained widespread application globally, playing a crucial role, especially in the drainage networks of residential and commercial buildings. my country's PVC pipe industry has developed rapidly, and among plastic pipes, PVC pipes have consistently led in usage, being widely used in water supply and drainage systems.

[0003] However, the anti-aging agents in existing PVC drainage pipes do not have any chemical interaction with the matrix resin. Therefore, the anti-aging agents inevitably migrate or detach from the PVC drainage pipes during use, and their anti-aging effect cannot be maintained for a long time, leading to aging of the PVC drainage pipes and malfunction of the pipeline. Therefore, there is an urgent need to develop a PVC drainage pipe with excellent anti-aging properties to extend its service life and ensure stable pipeline operation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a PVC drainage pipe and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A PVC drainage pipe material comprises the following raw materials in parts by weight: 90-100 parts PVC resin, 10-20 parts filler, 2-5 parts heat stabilizer, 1-4 parts chlorinated polyethylene, 1-3 parts coupling agent, 2-4 parts anti-aging agent, 1-1.5 parts lubricant, and 0.01-0.1 parts initiator.

[0007] Furthermore, the filler is one or more of calcium carbonate, talc, fumed silica, magnesium carbonate, wollastonite, mica, and titanium dioxide.

[0008] Furthermore, the heat stabilizer is a calcium-zinc composite stabilizer.

[0009] Furthermore, the coupling agent is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, and 3-(methacryloyloxy)propyltrimethoxysilane.

[0010] All coupling agents contain carbon-carbon double bonds. When added to PVC drainage pipes, they effectively disperse the filler, thereby significantly enhancing the wear resistance, heat resistance, and mechanical properties of the PVC drainage pipes. Furthermore, the coupling agents also introduce carbon-carbon double bonds onto the filler surface. Under the action of the initiator and during extrusion, these carbon-carbon double bonds react chemically with the carbon-carbon double bonds in the anti-aging agent and the unreacted carbon-carbon double bonds at the ends of the PVC resin. This results in a cross-linked hybrid network structure formed by the filler, anti-aging agent, and PVC resin. This structure ensures that the filler and anti-aging agent are highly dispersed and stably present in the PVC drainage pipes, preventing migration and detachment. This allows for a continuous and stable enhancement of the wear resistance, heat resistance, mechanical properties, oxidation resistance, and light stability of the PVC drainage pipes, thus extending their service life and ensuring normal pipeline operation.

[0011] Furthermore, the anti-aging agent is prepared by the following steps:

[0012] S1. 3,5-Di-tert-butyl-4-hydroxycinnamic acid, EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride), NHS (N-hydroxysuccinimide), and chloroform were added to a dry three-necked flask. After stirring to dissolve, diethylenetriamine was slowly added, and the temperature was raised to 60°C. The reaction was maintained at this temperature for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation, and column chromatography (using a mixed solvent of cyclohexane and ethyl acetate as the eluent, with a volume ratio of 1:1). Vacuum distillation was then performed to obtain intermediate 1. The ratio of 3,5-di-tert-butyl-4-hydroxycinnamic acid, diethylenetriamine, EDC, NHS, and chloroform was 28 g: 12.9 mL: 0.58 g: 0.35 g: 200 mL.

[0013] Under the influence of EDC and NHS, and with the molar ratio of 3,5-di-tert-butyl-4-hydroxycinnamic acid to diethylenetriamine controlled at 1:1.1-1.2, the -COOH group of 3,5-di-tert-butyl-4-hydroxycinnamic acid undergoes an amidation reaction with the -NH2 group of diethylenetriamine. The reaction equation is shown below:

[0014]

[0015] S2. Under nitrogen protection, 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid, triethylamine, and toluene were added to a three-necked flask and stirred until dissolved. Then, 10-bromo-1-decene was slowly added. After the addition was complete, the temperature was raised to 75°C and the reaction was stirred for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation, and column chromatography (using a mixed solvent of benzene and ethyl acetate as the eluent, with a volume ratio of benzene to ethyl acetate of 8:2). Vacuum distillation was performed to obtain intermediate 2. The molar ratio of 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid, 10-bromo-1-decene, triethylamine, and toluene was 21.5 g: 20 mL: 17 mL: 200 mL.

[0016] Triethylamine was used as an acid-binding agent, and the molar ratio of 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid and 10-bromo-1-decene was controlled at 1.05-1.1:1. The -NH- group of 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid underwent a substitution reaction with the -Br group of 10-bromo-1-decene, as shown in the following process:

[0017]

[0018] S3. Intermediate 1, EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride), NHS (N-hydroxysuccinimide), and dimethyl sulfoxide were added to a dry three-necked flask. After stirring and dissolving, intermediate 2 was slowly added, and the temperature was raised to 70°C. The reaction was maintained at this temperature for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation, and purified by column chromatography (using a mixed solvent of benzene and methanol as the eluent, with a volume ratio of benzene to methanol of 19:1). The ratio of intermediate 1, intermediate 2, EDC, NHS, and dimethyl sulfoxide was 21 g: 17 g: 0.029 g: 0.017 g: 240 mL.

[0019] Under the influence of EDC and NHS, and with the molar ratio of intermediate 1 to intermediate 2 controlled at 1.1-1.2:1, the -NH2 group of intermediate 1 and the -COOH group of intermediate 2 undergo an amidation reaction. The reaction equation is shown below:

[0020]

[0021] S4. Under nitrogen protection, polyvinyl chloride, triethylamine, intermediate 3, and DMF (N,N-dimethylformamide) were added to a thoroughly dried three-necked flask. After stirring and dissolving, the mixture was heated to 60°C and kept at that temperature for 9.5 hours. After the reaction was completed, the mixture was cooled to room temperature, then distilled under reduced pressure, and finally dried under vacuum at 50°C to obtain the anti-aging agent. The ratio of polyvinyl chloride, intermediate 3, triethylamine, and DMF was 46.9 g: 4.5 g: 1.1 mL: 260 mL.

[0022] Triethylamine acts as an acid-binding agent. The -NH- group of intermediate 3 undergoes a substitution reaction with the -Cl group of polyvinyl chloride, as shown in the following process:

[0023]

[0024] The anti-aging agent prepared by this invention contains hindered phenolic and hindered amine structures. The hindered phenolic structure can capture free radicals generated during the oxidation of polymers, interrupting the free radical chain reaction and thus preventing further oxidative degradation, thereby improving the antioxidant capacity of PVC drainage pipes. The hindered amine structure can effectively capture active free radicals generated by polymers under ultraviolet light, thus exerting a photostabilizing effect and achieving the purpose of preventing oxidation. The combined use of hindered phenolic structures exhibits excellent synergistic effects.

[0025] The anti-aging agent of this invention contains lipophilic ester groups, benzene rings, and long carbon chains, thus exhibiting good compatibility with other raw materials. It can be uniformly dispersed in PVC drainage pipes. Furthermore, the presence of carbon-carbon double bonds allows it to form a cross-linked hybrid network structure with fillers and PVC resin. This network structure enables the anti-aging agent to remain stably within the PVC drainage pipes, providing long-term, stable, and excellent antioxidant and light-stabilizing effects. In addition, the anti-aging agent also contains polyvinyl chloride macromolecular chains, which distinguishes it from commercially available small-molecule antioxidants. This results in better compatibility with PVC resin and reduced migration and release, further stabilizing the anti-aging agent within the PVC drainage pipes. This maximizes its antioxidant and light-stabilizing effects, extending the service life of the PVC drainage pipes and ensuring their normal operation.

[0026] Furthermore, the lubricant is one or more of paraffin wax, calcium stearate, oxidized polyethylene wax, and ethylene bis-stearamide.

[0027] Furthermore, the initiator is one or more of di(2-ethylhexyl) peroxide dicarbonate, azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide.

[0028] A method for preparing PVC drainage pipes includes the following steps:

[0029] Weigh each raw material according to weight and add it to a high-speed mixer for mixing. After hot mixing to 120℃-140℃, it is discharged into a low-speed cold mixer for cooling. After cold mixing to 45℃-55℃, the powder is discharged into the hopper of an extruder by a tube chain. It is then extruded and injection molded by an extruder and injection molded by an injection molding machine. After cooling, curing and shaping, PVC drainage pipes are obtained.

[0030] The beneficial effects of this invention are:

[0031] (1) The anti-aging agent of the present invention forms a cross-linked hybrid network structure with the filler and PVC resin. Therefore, the filler and anti-aging agent can be highly dispersed and stably exist in the PVC drainage pipe, and are not easy to migrate and fall out. They can continuously and stably enhance the wear resistance, heat resistance, mechanical properties, oxidation resistance and light stability of the PVC drainage pipe, thereby extending the service life of the PVC drainage pipe and ensuring the normal operation of the pipeline.

[0032] (2) The anti-aging agent of the present invention contains polyvinyl chloride macromolecular chains, which makes the anti-aging agent of the present invention different from commercially available small molecule antioxidants. It can not only be more compatible with PVC resin, but also less prone to migration and release, and can be further stabilized in PVC drainage pipes, giving full play to its antioxidant and light-stabilizing effects. Detailed Implementation

[0033] 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.

[0034] Sources of raw materials used in all embodiments and comparative examples:

[0035] 3,5-Di-tert-butyl-4-hydroxycinnamic acid: CAS No. 22014-01-3, Shanghai Mairui Biochemical Technology Co., Ltd., purity 98%;

[0036] Diethylenetriamine: CAS No. 111-40-0, Aladdin Biochemical Technology Co., Ltd., purity ≥98.5%;

[0037] 2-(2,2,6,6-Tetramethylpiperidin-4-yl)acetic acid: CAS No. 34635-77-3, Beijing Bailingwei Technology Co., Ltd.;

[0038] 10-Bromo-1-decene: CAS No. 62871-09-4, Aladdin Biochemical Technology Co., Ltd., purity ≥95%;

[0039] Polyvinyl chloride: CAS No. 9002-86-2, Aladdin Biochemical Technology Co., Ltd., K value 59-55;

[0040] EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride): CAS No. 25952-53-8, Jier Biochemical (Shanghai) Co., Ltd., purity 98%;

[0041] NHS (N-hydroxysuccinimide): CAS No. 6066-82-6, Aladdin Biochemical Technology Co., Ltd., purity 98%;

[0042] Triethylamine: CAS No. 121-44-8, Jiangsu Runfeng Synthetic Technology Co., Ltd., purity 99%;

[0043] Dimethyl sulfoxide: CAS No. 67-68-5, Shandong Nabaichuan Chemical Sales Co., Ltd., purity 99.99%;

[0044] DMF (N,N-dimethylformamide): CAS No. 68-12-2, Shanghai Mairui Biochemical Technology Co., Ltd., purity ≥99.9%;

[0045] Antioxidant 1076: CAS No. 2082-79-3, Aladdin Biochemical Technology Co., Ltd.;

[0046] Light stabilizer 944: CAS No. 71878-19-8, Aladdin Biochemical Technology Co., Ltd.

[0047] Example 1: Preparation of an anti-aging agent, the specific steps are as follows:

[0048] S1. 28 g of 3,5-di-tert-butyl-4-hydroxycinnamic acid, 0.58 g of EDC, 0.35 g of NHS and 200 mL of chloroform were added to a 500 mL dry three-necked flask. After stirring and dissolving, 12.9 mL of diethylenetriamine was slowly added. The temperature was then raised to 60 °C and the reaction was maintained for 6 h. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation and column chromatography (the eluent was a mixture of cyclohexane and ethyl acetate in a volume ratio of 1:1). Vacuum distillation was then performed to obtain intermediate 1.

[0049] S2. Under nitrogen protection, 21.5 g of 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid, 17 mL of triethylamine, and 200 mL of toluene were added to a 500 mL three-necked flask. After stirring and dissolving, 20 mL of 10-bromo-1-decene was slowly added. After the addition was complete, the temperature was raised to 75 °C and the reaction was stirred for 3 h. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation, and column chromatography (using a mixed solvent of benzene and ethyl acetate as the eluent, with a volume ratio of benzene to ethyl acetate of 8:2). Vacuum distillation yielded intermediate 2.

[0050] S3. Add 21g of intermediate 1, 0.029g of EDC, 0.017g of NHS and 240mL of dimethyl sulfoxide to a 500mL dry three-necked flask. After stirring to dissolve, slowly add 17g of intermediate 2, then heat to 70℃ and keep the temperature for 8h. After the reaction is completed, cool to room temperature, distill under reduced pressure, and purify by column chromatography (the eluent is a mixed solvent of benzene and methanol, with a volume ratio of benzene to methanol of 19:1). Distill under reduced pressure to obtain intermediate 3.

[0051] S4. Under nitrogen protection, 46.9 g of polyvinyl chloride, 1.1 mL of triethylamine, 4.5 g of intermediate 3 and 260 mL of DMF were added to a 500 mL thoroughly dried three-necked flask. After stirring and dissolving, the mixture was heated to 60 °C and kept at that temperature for 9.5 h. After the reaction was completed, the mixture was cooled to room temperature, then distilled under reduced pressure, and finally dried under vacuum at 50 °C to obtain the anti-aging agent.

[0052] Example 2: Preparation of an anti-aging agent, the specific steps are as follows:

[0053] The remaining steps remain unchanged, except for step S4 of Example 1, which is removed to prepare the anti-aging agent.

[0054] Example 3: Preparation of PVC drainage pipes, the specific steps are as follows:

[0055] Weigh out 90 parts by weight of PVC resin, 3 parts of calcium carbonate, 3 parts of mica, 4 parts of titanium dioxide, 2 parts of calcium-zinc composite stabilizer, 1 part of chlorinated polyethylene, 1 part of vinyltrimethoxysilane, 2 parts of the anti-aging agent prepared in Example 1, 1 part of paraffin wax, and 0.01 parts of dicumyl peroxide, and add them to a high-speed mixer for mixing. After hot mixing to 120°C, the mixture is then discharged into a low-speed cold mixer for cooling. After cold mixing to 45°C, the powder is discharged into the hopper of an extruder by a pipe chain. The mixture is then extruded and injection molded. After cooling, curing, and shaping, PVC drainage pipes are obtained.

[0056] Example 4: Preparation of PVC drainage pipes, the specific steps are as follows:

[0057] Weigh out 95 parts by weight of PVC resin, 3 parts of talc powder, 3 parts of fumed silica, 3 parts of magnesium carbonate, 3 parts of wollastonite, 4 parts of titanium dioxide, 4 parts of calcium-zinc composite stabilizer, 3 parts of chlorinated polyethylene, 1 part of vinyltrimethoxysilane, 1 part of 3-(methacryloyloxy)propyltrimethoxysilane, 3 parts of the anti-aging agent prepared in Example 1, 0.6 parts of calcium stearate, 0.6 parts of oxidized polyethylene wax, 0.05 parts of benzoyl peroxide, and dicumyl peroxide, and add them to a high-speed mixer for mixing. After hot mixing to 140°C, the mixture is then discharged into a low-speed cold mixer for cooling. After cold mixing to 55°C, the powder is discharged into the hopper of an extruder by a pipe chain. The mixture is then extruded and injection molded. After cooling, curing, and shaping, PVC drainage pipes are obtained.

[0058] Example 5: Preparation of PVC drainage pipes, the specific steps are as follows:

[0059] Weigh out 100 parts by weight of PVC resin, 5 parts of calcium carbonate, 5 parts of magnesium carbonate, 5 parts of mica, 5 parts of titanium dioxide, 5 parts of calcium-zinc composite stabilizer, 4 parts of chlorinated polyethylene, 3 parts of vinyltriethoxysilane, 4 parts of the anti-aging agent prepared in Example 1, 0.5 parts of paraffin wax, 0.5 parts of calcium stearate, 0.5 parts of ethylene bis-stearamide, and 0.1 parts of di(2-ethylhexyl) peroxide dicarbonate and add them to a high-speed mixer for mixing. After hot mixing to 130°C, the mixture is then discharged into a low-speed cold mixer for cooling. After cold mixing to 50°C, the powder is discharged into the hopper of an extruder by a pipe chain. The mixture is then extruded and injection molded. After cooling, curing, and shaping, PVC drainage pipes are obtained.

[0060] Comparative Example 1: Preparation of PVC drainage pipes, the specific steps are as follows:

[0061] The remaining steps remain unchanged, except that the anti-aging agent in Example 3 is replaced with the anti-aging agent prepared in Example 2, thereby preparing PVC drainage pipes.

[0062] Comparative Example 2: Preparation of PVC drainage pipes, the specific steps are as follows:

[0063] The remaining steps remain unchanged, except that the anti-aging agent in Example 3 is replaced with 1 part antioxidant 1076 and 1 part light stabilizer 944, thereby preparing PVC drainage pipes.

[0064] Performance testing

[0065] The following performance tests were conducted on Examples 3-5 and Comparative Examples 1-2, and the test results for all items are shown in Table 1:

[0066] Tensile strength test: Refer to GB / T 1040.2-2022 Determination of tensile properties of plastics, Part II;

[0067] Aging test:

[0068] (1) The test was conducted in accordance with GB / T 16422.3-2014 "Laboratory Light Source Exposure Test Method for Plastics - Part 3: Fluorescent Ultraviolet Lamp". The wavelength of the ultraviolet lamp was 313 nm. The sample was irradiated at 70°C for a total test duration of 150 h. Tensile strength test was performed.

[0069] (2) Dry heat aging at 105℃ for 150h, and tensile strength test was performed in accordance with GB / T 1040.2-2022 Determination of tensile properties of plastics, Part II.

[0070] Table 1

[0071]

[0072] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0073] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A PVC drainage pipe, characterized in that, The raw materials include the following parts by weight: 90-100 parts PVC resin, 10-20 parts filler, 2-5 parts heat stabilizer, 1-4 parts chlorinated polyethylene, 1-3 parts coupling agent, 2-4 parts anti-aging agent, 1-1.5 parts lubricant, and 0.01-0.1 parts initiator; The anti-aging agent is prepared through the following steps: S1. 3,5-Di-tert-butyl-4-hydroxycinnamic acid, EDC, NHS, and chloroform were added to a flask, stirred, and then diethylenetriamine was added. The mixture was heated to 60°C and reacted for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, purified by column chromatography under reduced pressure, and then purified by distillation under reduced pressure to obtain intermediate 1. The ratio of 3,5-di-tert-butyl-4-hydroxycinnamic acid, diethylenetriamine, EDC, NHS, and chloroform was 28 g: 12.9 mL: 0.58 g: 0.35 g: 200 mL. S2. Under nitrogen protection, 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid, triethylamine, and toluene were added to a flask, stirred, and then 10-bromo-1-decene was added. The mixture was heated to 75°C and reacted for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, purified by column chromatography under reduced pressure, and then purified by distillation under reduced pressure to obtain intermediate 2. The molar ratio of 2-(2,2,6,6-tetramethylpiperidin-4-yl)acetic acid, 10-bromo-1-decene, triethylamine, and toluene was 21.5 g: 20 mL: 17 mL: 200 mL. S3. Add intermediate 1, EDC, NHS and dimethyl sulfoxide to a flask, stir, add intermediate 2, heat to 70℃ and react for 8 hours, cool to room temperature, distill under reduced pressure, purify by column chromatography, and distill under reduced pressure to obtain intermediate 3; the ratio of intermediate 1, intermediate 2, EDC, NHS and dimethyl sulfoxide is 21g:17g:0.029g:0.017g:240mL; S4. Under nitrogen protection, polyvinyl chloride, triethylamine, intermediate 3 and DMF were added to a flask, stirred and heated to 60°C, and reacted for 9.5 h. After the reaction was completed, the mixture was cooled to room temperature, distilled under reduced pressure and dried to obtain the anti-aging agent. The ratio of polyvinyl chloride, intermediate 3, triethylamine and DMF was 46.9 g: 4.5 g: 1.1 mL: 260 mL.

2. The PVC drainage pipe according to claim 1, characterized in that, The coupling agent is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, and 3-(methacryloyloxy)propyltrimethoxysilane.

3. A PVC drainage pipe according to claim 1, characterized in that, The filler is one or more of the following: calcium carbonate, talc, fumed silica, magnesium carbonate, wollastonite, mica, and titanium dioxide.

4. A PVC drainage pipe according to claim 1, characterized in that, The heat stabilizer is a calcium-zinc composite stabilizer.

5. A PVC drainage pipe according to claim 1, characterized in that, The lubricant is one or more of paraffin wax, calcium stearate, oxidized polyethylene wax, and ethylene bis-stearamide.

6. A PVC drainage pipe according to claim 1, characterized in that, The initiator is one or more of di(2-ethylhexyl) peroxide dicarbonate, azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide.

7. The method for preparing a PVC drainage pipe according to claim 1, characterized in that, Includes the following steps: Weigh each raw material according to weight and add it to a high-speed mixer for mixing. After hot mixing to 120℃-140℃, it is discharged into a low-speed cold mixer for cooling. After cold mixing to 45℃-55℃, the powder is discharged into the hopper of an extruder by a tube chain. It is then extruded and injection molded by an extruder and injection molded by an injection molding machine. After cooling, curing and shaping, PVC drainage pipes are obtained.

Images