Low-temperature-resistant, high-strength, high-wear-resistance polyvinyl chloride nanocomposite material, and preparation method and application thereof

Abstract

This invention relates to the field of polymer materials technology, specifically to a low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride (PVC) nanocomposite material, its preparation method, and its applications. The PVC nanocomposite material comprises the following raw materials in parts by weight: 100 parts PVC resin, 1.3-5 parts stabilizer, 0.5-1.5 parts internal lubricant, 0.5-1.5 parts external lubricant, 1.5-3.5 parts processing aid, 1-12 parts MBS resin, 0-8 parts CPE resin, 5-15 parts filler, and 5-10 parts modified nano-alumina. This invention improves the low-temperature toughness and wear resistance of PVC while ensuring that the flexural strength and flexural modulus of the composite PVC are not affected.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a low-temperature resistant, high-strength, and highly wear-resistant polyvinyl chloride nanocomposite material, its preparation method, and its application. Background Technology

[0002] Idler rollers are one of the most widely used and crucial components in belt conveyors, supporting the weight of the conveyor belt and materials. They are extensively used in industries such as mining, chemical, coking, steel, and metallurgy. Because idler rollers are constantly exposed to harsh environments, including open fields, dusty conditions, and highly corrosive environments, and frequently come into contact with and rub against materials and the conveyor belt, their quality is closely related to their overall performance, particularly their mechanical strength, wear resistance, corrosion resistance, and low-temperature toughness. Currently, idler roller tubes are generally made of steel or plastic. Steel tubes suffer from drawbacks such as high weight, high energy consumption, susceptibility to corrosion and wear, and a short service life. Plastic tubes are typically made of ultra-high molecular weight polyethylene (UHMWPE) or PA-6. While UHMWPE offers high wear resistance and impact resistance, it is flammable, has poor processability, and is expensive. PA-6 boasts high mechanical strength and excellent fatigue resistance, but it is not resistant to strong acids and oxidizing agents, and it is hygroscopic, requiring sophisticated injection molding processes.

[0003] Polyvinyl chloride (PVC) is a polymer synthesized from vinyl chloride monomer (VCM) through a free radical polymerization mechanism under the initiator of peroxides, azo compounds, or under the influence of light and heat. The -Cl group in the PVC molecular chain endows it with excellent flame retardancy. This type of polymer has high mechanical strength, excellent resistance to chemical corrosion, especially strong acid corrosion, good insulation properties, and is inexpensive and easy to produce. Due to these advantages, PVC has become a major material for pipes and fittings; however, its poor wear resistance and low-temperature toughness limit its application in idler roller tubes.

[0004] Current technologies generally employ a combination of multiple wear-resistant additives or the addition of inorganic nanomaterials to improve the wear resistance of PVC. While using multiple wear-resistant additives can improve the wear resistance of polyPVC to some extent, the poor toughness of PVC often necessitates the selection of a toughening agent to enhance its toughness. This method uses a wide variety of additives, and the particle size requirements for the wear-resistant additives are quite stringent, as particle size affects the dispersibility of the wear-resistant additives in PVC and significantly impacts its toughness. Adding inorganic nanomaterials can significantly improve the wear resistance of PVC, but the PVC produced by this method has relatively low toughness, making it prone to cracking during transportation and use. Furthermore, inorganic nanomaterials are not easily dispersed in PVC, resulting in relatively poor processing performance. Summary of the Invention

[0005] To address the problem that polyvinyl chloride (PVC) is difficult to use in the preparation of idler roller tubes due to its poor wear resistance and low-temperature toughness in existing technologies, this invention provides a low-temperature resistant, high-strength, and highly wear-resistant PVC nanocomposite material, its preparation method, and its application. The synergistic effect between MBS resin and CPE resin improves the low-temperature toughness of PVC, and the modified nano-alumina improves the wear resistance of PVC without affecting its toughness.

[0006] In a first aspect, the present invention provides a low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite material, comprising the following raw materials in parts by weight: 100 parts of PVC resin, 1.3-5 parts of stabilizer, 0.5-1.5 parts of internal lubricant, 0.5-1.5 parts of external lubricant, 1.5-3.5 parts of processing aid, 1-12 parts of MBS resin, 0-8 parts of CPE resin, 5-15 parts of filler, and 5-10 parts of modified nano-alumina.

[0007] Furthermore, the degree of polymerization of the PVC resin is 1000-1500. This invention controls the degree of polymerization of the PVC resin within a narrow range of 1000-1500, which on the one hand ensures the relative stability of the processing performance and mechanical properties of the PVC resin, and on the other hand helps to balance the processability and mechanical properties of the PVC resin.

[0008] Furthermore, the preparation method of modified nano-alumina includes the following steps:

[0009] Step 1: Mix nano-alumina, coupling agent, and dispersant to obtain a mixture;

[0010] Step 2: Ball mill the mixture obtained in Step 1;

[0011] Step 3: Add the modifier to the ball mill and continue ball milling to obtain the modified nano-alumina crude product;

[0012] Step 4: After centrifuging, washing and drying the crude modified nano-alumina obtained in Step 3, the modified nano-alumina is obtained.

[0013] The ball milling process uses grinding media with a particle size of 0.05-0.5 mm. The grinding media can be any one of zirconia beads, silicon carbide, or silicon nitride. Ball milling can pulverize nano-alumina, promote the mixing of nano-alumina with modifiers and dispersants, and also classify modified nano-alumina.

[0014] Furthermore, in step one, the mass ratio of nano-alumina, coupling agent, and dispersant is 1:0.3-0.6:20-600.

[0015] Furthermore, in step two, the ball milling temperature is 30-60℃, the ball milling speed is 100-800 rpm, and the ball milling time is 2-6 hours.

[0016] Furthermore, in step three, the temperature and rotation speed of the ball milling process are the same as in step two, the mass ratio of nano-alumina to modifier is 1-9:1, and the ball milling process is continued for 6-8 hours.

[0017] Furthermore, the coupling agent is any one of titanate coupling agents, aluminate coupling agents, or silane coupling agents. The dispersant is water or an organic solvent, with the organic solvent being any one of dichloroethane, acetone, or ethyl acetate. The modifier is a polyacrylate polymer, specifically poly(hydroxyethyl methacrylate) or a copolymer of acrylate and styrene monomers, preferably ACR resin. The polyacrylate polymer can coat nano-alumina, improving the compatibility between nano-alumina and PVC resin; the dispersant enables the modified nano-alumina to be uniformly dispersed, preventing agglomeration.

[0018] Furthermore, in step four, the modified nano-alumina has a mesh size of 800-2500 and a coating thickness of 8-26 nm.

[0019] Furthermore, the stabilizer is any one or two of organotin stabilizers, calcium-zinc stabilizers, and lead salt stabilizers, with calcium-zinc stabilizers being preferred. Calcium-zinc stabilizers have good thermal stability and weather resistance, and exhibit good dispersibility in PVC resin; they are non-toxic and environmentally friendly stabilizers.

[0020] The internal lubricant is at least one of stearate polymers, oxidized polyethylene wax, and polyol ester polymers. The internal lubricant reduces friction between PVC molecular chains and between PVC and additives during the processing of PVC idler rollers, improving the compatibility between PVC resin and modified nano-alumina. The polyol ester polymer also exhibits low-temperature resistance and excellent wear resistance, working in conjunction with MBS resin and CPE resin to enhance the low-temperature resistance and wear resistance of PVC idler rollers.

[0021] The external lubricant is any one or both of PE wax and paraffin wax.

[0022] Furthermore, the filler is nano-calcium carbonate or nano-barium sulfate. Nano-activated calcium carbonate can improve the flexural strength and flexural modulus of PVC roller tubes, improve their thermal stability, and synergistically increase the toughness of PVC roller tubes with CPE resin. Nano-activated barium sulfate is an environmentally friendly inorganic filler that can increase impact strength, flexural strength, and flexural modulus without reducing the impact strength of PVC roller tubes, while also reducing costs, giving the tubes excellent weather resistance, allowing PVC roller tubes to be used in harsh outdoor environments, and also imparting high thermal conductivity and rheological properties to PVC roller tubes, shortening the material molding cycle. The processing aid is an acrylate copolymer. Acrylate copolymers can enhance the weather resistance and chemical corrosion resistance of PVC roller tubes, while also improving their wear resistance. Acrylate copolymers can also promote the plasticization of PVC resin and improve the processing performance of PVC resin.

[0023] Secondly, the present invention provides a method for preparing the low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite material as described above, comprising the following steps:

[0024] Step (1): Weigh out PVC resin, stabilizer, internal lubricant, external lubricant, processing aid, MBS resin, CPE resin, filler and modified nano alumina according to the proportion. Put the above raw materials into a high-speed mixer for stirring and heating to obtain a mixture. When the temperature of the mixture reaches 120°C, transfer it to a low-speed mixer for stirring and cooling to 45°C. Discharge the cooled mixture into the hopper for later use.

[0025] Step (2): Add the mixed material to be used in the hopper to the twin-screw extruder for extrusion and granulation. The temperature control of each zone of the twin-screw extruder is as follows: Zone 1 of the barrel 1 130-145℃, Zone 2 of the barrel 140-150℃, Zone 3 of the barrel 145-155℃, Zone 4 of the barrel 145-160℃, Zone 5 of the barrel 145-165℃, Zone 6 of the barrel 150-165℃, to obtain polyvinyl chloride nanocomposite particles.

[0026] Thirdly, the present invention provides an application of the low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite material as described above in the preparation of idler roller tubes, comprising the following steps:

[0027] S1: Polyvinyl chloride nanocomposite particles are added to an extruder and extruded. The temperature control of each zone of the extruder is as follows: Zone 1 of the barrel 150-160℃, Zone 2 of the barrel 155-165℃, Zone 3 of the barrel 155-170℃, Zone 4 of the barrel 160-170℃, Zone 1 of the die head 170-180℃, Zone 2 of the die head 170-180℃, Zone 3 of the die head 175-180℃, Zone 4 of the die head 175-185℃, Zone 5 of the die head 180-190℃, Zone 6 of the die head 170-180℃, to obtain a polyvinyl chloride nanocomposite tube.

[0028] S2: The polyvinyl chloride nanocomposite tube obtained in S1 is sized. After the tube cools, it is cut to the required size to obtain a low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite roller tube.

[0029] The low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite roller tubes described above can be used in coal mine belt conveyors, roller tube bodies, or bearing housings.

[0030] The beneficial effects of this invention are as follows:

[0031] The MBS resin and CPE resin selected in this invention, used as composite toughening agents, can form a distinct network-island structure in PVC, improving the impact resistance of PVC under low-temperature conditions. CPE resin is used to improve the low-temperature toughness and impact resistance of nanocomposite PVC; MBS resin is used to enhance the toughness of nanocomposite PVC and improve the compatibility between CPE and PVC resins; and stabilizers are used to improve the thermal stability of nanocomposite PVC, ensuring that the nanocomposite PVC pipes will not decompose or discolor due to heat during extrusion molding.

[0032] This invention improves the low-temperature toughness and wear resistance of PVC by introducing self-made modified nano-alumina into PVC resin, while ensuring that the flexural strength and flexural modulus of the composite PVC are not affected. This invention uses an acrylate copolymer modifier to coat the modified nano-alumina, resulting in more uniform dispersion and stronger bonding of the nano-alumina in PVC. This improves the wear resistance of PVC without reducing its toughness. The acrylate copolymer modifier itself can also promote PVC plasticization and improve its processing performance. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0034] Test pieces of polyvinyl chloride nanocomposites from Examples 1-5 were prepared according to the following preparation method:

[0035] Step (1): Weigh the following raw materials in the following proportions: 100 parts of PVC resin with a degree of polymerization of 1300, 4 parts of calcium-zinc stabilizer, 0.5 parts of glyceryl monostearate, 0.6 parts of PE wax, 2 parts of processing aid, 7 parts of MBS resin, 5 parts of nano calcium carbonate and 5 parts of modified nano alumina. Put the above raw materials into a high-speed mixer for stirring and heating to obtain a mixture. When the temperature of the mixture reaches 120°C, transfer it to a low-speed mixer for stirring and cooling to 45°C. Discharge the cooled mixture into the hopper for later use.

[0036] Step (2): Add the mixed material to be used in the hopper to the twin-screw extruder for extrusion and granulation. The temperature control of each zone of the twin-screw extruder is as follows: Zone 1 of the barrel 1 130-145℃, Zone 2 of the barrel 140-150℃, Zone 3 of the barrel 145-155℃, Zone 4 of the barrel 145-160℃, Zone 5 of the barrel 145-165℃, Zone 6 of the barrel 150-165℃, to obtain polyvinyl chloride nanocomposite particles.

[0037] Step (3): The polyvinyl chloride nanocomposite particles obtained in step (2) are mixed in a 300 ml internal mixer at a torque rheometer temperature of 185℃ for 4 min to obtain molten material; the molten material is pressed into 4 mm and 6 mm polyvinyl chloride nanocomposite test pieces on a tablet press at a temperature of 185℃.

[0038] The preparation method of modified nano-alumina includes the following steps:

[0039] Step 1: Mix nano-alumina, coupling agent and dispersant to obtain a mixture.

[0040] Step 2: The mixture obtained in Step 1 is subjected to ball milling. The ball milling media used in the ball milling process are zirconia beads with a particle size of 0.05-0.5 mm. The ball milling temperature is 50℃.

[0041] Step 3: Add the modifier to the ball mill and continue ball milling at the same speed for 8 hours. The ball milling temperature is 50℃ to obtain the modified nano-alumina crude product.

[0042] Step 4: After centrifuging, washing and drying the crude modified nano-alumina obtained in Step 3, the modified nano-alumina is obtained.

[0043] The difference between Examples 1-5 lies in the different preparation methods of the modified nano-alumina. The specific component dosages used in the preparation process of the modified nano-alumina and the process parameters of the ball milling treatment in step two are shown in Table 1.

[0044] Table 1. Component dosage and process parameters for preparing modified nano-alumina in Examples 1-5

[0045]

[0046] The performance of the test pieces obtained in Examples 1-5 were tested respectively. The test standards and test results of each performance index are shown in Table 2.

[0047] Table 2. Performance test results of the specimens obtained in Examples 1-5

[0048]

[0049] As shown in Table 2, the friction coefficient of the specimen obtained in Example 4 is 0.118, which is the lowest among the specimens obtained in Examples 1-5. It can be seen that under the premise that the preparation method of polyvinyl chloride nanocomposite material is the same, when the mass ratio of nano alumina, dichloroethane, titanate coupling agent and polyhydroxyethyl methacrylate is controlled at 7:400:2.1:1, and the ball milling speed in step two of the modified nano alumina preparation method is set to 400 rpm and the ball milling time is set to 5 h, the wear resistance coefficient of polyvinyl chloride nanocomposite material is the lowest.

[0050] Example 6

[0051] A sample of a low-temperature resistant, high-strength, and highly wear-resistant polyvinyl chloride nanocomposite material is prepared by the following steps:

[0052] Step (1): Weigh the following raw materials in the following proportions: 100 parts of PVC resin with a degree of polymerization of 1300, 4 parts of calcium-zinc stabilizer, 0.5 parts of glyceryl monostearate, 0.6 parts of PE wax, 2 parts of acrylate copolymer, 7 parts of MBS resin, 1 part of CPE resin, 5 parts of nano calcium carbonate, and 5 parts of modified nano alumina prepared in Example 4. Introduce the above raw materials into a high-speed mixer for stirring and heating to obtain a mixture. When the temperature of the mixture reaches 120°C, transfer it to a low-speed mixer for stirring and cooling to 45°C. Discharge the cooled mixture into a hopper for later use.

[0053] Step (2): Add the mixed material to be used in the hopper to the twin-screw extruder for extrusion and granulation. The temperature control of each zone of the twin-screw extruder is as follows: Zone 1 of the barrel 1 130-145℃, Zone 2 of the barrel 140-150℃, Zone 3 of the barrel 145-155℃, Zone 4 of the barrel 145-160℃, Zone 5 of the barrel 145-165℃, Zone 6 of the barrel 150-165℃, to obtain polyvinyl chloride nanocomposite particles.

[0054] Step (3): The polyvinyl chloride nanocomposite particles obtained in step (2) are mixed in a 300 ml internal mixer at a torque rheometer temperature of 185℃ for 4 min to obtain molten material; the molten material is pressed into 4 mm and 6 mm polyvinyl chloride nanocomposite particle test pieces on a tablet press at a temperature of 185℃.

[0055] The only difference between Examples 7-11, Comparative Examples 1-2 and Example 6 is the amount of MBS resin and CPE resin used. The difference between Comparative Example 3 and Example 6 is the amount of MBS resin and CPE resin used and the absence of modified nano-alumina. The specific raw materials and weight parts used in the low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposites prepared in Examples 6-11 and Comparative Examples 1-3 are shown in Table 3.

[0056] Table 3. Specific raw materials and weight parts of Examples 6-11 and Comparative Examples 1-3

[0057]

[0058] The performance of the test pieces in Examples 6-11 and Comparative Examples 1-3 were tested respectively. The test standards and test results of each performance index are shown in Table 4.

[0059] Table 4. Performance of the specimens in Examples 6-11 and Comparative Examples 1-3

[0060]

[0061] As shown in Table 4, the coefficients of friction of the specimens obtained in Examples 6-11 are all lower than those of the specimen obtained in Comparative Example 3, indicating that modified nano-alumina helps to improve the wear resistance of PVC nanocomposite materials. Although the notched impact strength of the specimen obtained in Comparative Example 1 is relatively high at -20℃, its coefficient of friction is 0.121, indicating that although Comparative Example 1 used modified nano-alumina, the use of only MBS resin as a single toughening agent resulted in a certain improvement in low-temperature toughness, but no significant improvement in wear resistance. The notched impact strength of the specimen obtained in Comparative Example 2 at -20℃ is lower than that of the specimens obtained in Examples 6-11, and its coefficient of friction is 0.121, indicating that although Comparative Example 2 used modified nano-alumina, the use of only CPE resin as a single toughening agent did not significantly improve the wear resistance of the specimen. Furthermore, due to the poor compatibility between CPE resin and PVC resin, the low-temperature toughness of the specimen obtained in Comparative Example 2 was not significantly improved. In Examples 6-11, the specimen obtained in Example 9 exhibited the highest notched impact strength at -20°C, at 13.5 KJ / m. 2 The sample obtained in this embodiment had the lowest coefficient of friction, 0.112, indicating that when MBS resin and CPE resin are compounded in a mass ratio of 1:1 as a composite toughening agent, the polyvinyl chloride nanocomposite material has the highest low-temperature toughness and the best wear resistance.

[0062] Example 12

[0063] The preparation of idler roller tubes using polyvinyl chloride nanocomposite particles obtained in step (2) of any of Examples 1-11 includes the following steps:

[0064] S1: Polyvinyl chloride nanocomposite particles are added to an extruder and extruded. The temperature control of each zone of the extruder is as follows: Zone 1 of the barrel 150-160℃, Zone 2 of the barrel 155-165℃, Zone 3 of the barrel 155-170℃, Zone 4 of the barrel 160-170℃, Zone 1 of the die head 170-180℃, Zone 2 of the die head 170-180℃, Zone 3 of the die head 175-180℃, Zone 4 of the die head 175-185℃, Zone 5 of the die head 180-190℃, Zone 6 of the die head 170-180℃, to obtain a polyvinyl chloride nanocomposite particle tube.

[0065] S2: The polyvinyl chloride nanocomposite particle tube obtained in S1 is sized. After the tube cools, it is cut according to the required size to obtain a low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite roller tube.

[0066] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A low temperature resistant, high strength, high wear resistant polyvinyl chloride nanocomposite material, characterized in that, The raw materials include the following parts by weight: 100 parts PVC resin, 1.3-5 parts stabilizer, 0.5-1.5 parts internal lubricant, 0.5-1.5 parts external lubricant, 1.5-3.5 parts processing aid, 4 parts MBS resin, 4 parts CPE resin, 5-15 parts filler, and 5-10 parts modified nano alumina. The preparation method of the modified nano-alumina includes the following steps: Step 1: Mix nano-alumina, coupling agent, and dispersant to obtain a mixture; Step 2: Ball mill the mixture obtained in Step 1; Step 3: Add the modifier to the ball mill and continue ball milling to obtain the modified nano-alumina crude product; Step 4: The modified nano-alumina crude product obtained in Step 3 is centrifuged, washed, and dried to obtain modified nano-alumina; In step one, the mass ratio of nano-alumina, coupling agent, and dispersant is 1:0.3-0.6:20-600; In step two, the ball milling temperature is 30-60℃, the ball milling speed is 100-800 rpm, and the ball milling time is 2-6 hours. In step three, the mass ratio of nano-alumina to modifier is 1-9:1, and the ball milling treatment continues for 6-8 hours. The coupling agent is any one of titanate coupling agents, aluminate coupling agents, and silane coupling agents; the dispersant is water or an organic solvent; and the modifier is a polyacrylate polymer. The degree of polymerization of PVC resin is 1300-1500; The preparation method of the aforementioned low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite material includes the following steps: Step (1): Weigh out PVC resin, stabilizer, internal lubricant, external lubricant, processing aid, MBS resin, CPE resin, filler and modified nano alumina according to the proportion. Put the above raw materials into a high-speed mixer for stirring and heating to obtain a mixture. When the temperature of the mixture reaches 120°C, transfer it to a low-speed mixer for stirring and cooling to 45°C. Discharge the cooled mixture into the hopper for later use. Step (2): Add the mixed material to be used in the hopper to the twin-screw extruder for extrusion and granulation. The temperature control of each zone of the twin-screw extruder is as follows: Zone 1 of the barrel 1 130-145℃, Zone 2 of the barrel 140-150℃, Zone 3 of the barrel 145-155℃, Zone 4 of the barrel 145-160℃, Zone 5 of the barrel 145-165℃, Zone 6 of the barrel 150-165℃, to obtain polyvinyl chloride nanocomposite particles.

2. The low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite material as described in claim 1, characterized in that, The stabilizer is any one or two of organotin stabilizers, calcium-zinc stabilizers, and lead salt stabilizers; the internal lubricant is at least one of stearate polymers, oxidized polyethylene wax, and polyol ester polymers; the external lubricant is any one or two of PE wax and paraffin wax; the filler is nano-calcium carbonate or nano-barium sulfate; and the processing aid is an acrylate copolymer.

3. The application of the low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite material as described in claim 1 in the preparation of idler roller tubes, characterized in that, Includes the following steps: S1: Polyvinyl chloride nanocomposite particles are added to an extruder and extruded. The temperature control of each zone of the extruder is as follows: Zone 1 of the barrel 150-160℃, Zone 2 of the barrel 155-165℃, Zone 3 of the barrel 155-170℃, Zone 4 of the barrel 160-170℃, Zone 1 of the die head 170-180℃, Zone 2 of the die head 170-180℃, Zone 3 of the die head 175-180℃, Zone 4 of the die head 175-185℃, Zone 5 of the die head 180-190℃, Zone 6 of the die head 170-180℃, to obtain a polyvinyl chloride nanocomposite tube. S2: The polyvinyl chloride nanocomposite tube obtained in S1 is sized. After the tube cools, it is cut to the required size to obtain a low-temperature resistant, high-strength, and high-wear-resistant polyvinyl chloride nanocomposite roller tube.

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