Cold-resistant insulation-grade flexible polyvinyl chloride cable material and preparation method thereof

Abstract

The invention belongs to the technical field of cable preparation, and particularly relates to a cold-resistant insulation-grade flexible polyvinyl chloride cable material and a preparation method thereof. The PVC composite material comprises the following components in parts by mass: 100 parts of PVC resin powder, 10-30 parts of an inorganic filler, 40-70 parts of a plasticizer, 0.2-0.6 part of a processing aid A, 0.2-0.6 part of a processing aid B and 3-7 parts of a stabilizer, the inorganic filler is active nano calcium carbonate. The preparation method comprises the following steps: mixing the raw materials into a high-speed mixer at the temperature of 100-150 DEG C for 10-20 minutes to obtain a uniform mixture, and discharging the uniform mixture into a granulation process feeding bin; and feeding the mixture into a double-stage extrusion granulator consisting of double screws and a single screw, and carrying out extrusion granulation to obtain the cold-resistant insulation-grade flexible polyvinyl chloride cable material. The problems that an existing flexible polyvinyl chloride cable material is poor in cold resistance, and an existing cold-resistant insulation-grade flexible polyvinyl chloride cable material is high in cost and complex to prepare are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of cable preparation, and in particular relates to a cold-resistant insulating-grade soft polyvinyl chloride cable material and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) resin is flame-retardant, oil-resistant, corona-resistant, and has excellent mechanical and processing properties. It is widely used in the insulation and sheathing of wires and cables. Currently, the cold-resistant temperature of ordinary PVC cable materials is between -15°C and -20°C. However, in cold regions where winter temperatures often drop below -40°C, wires and cables must exhibit excellent cold resistance and flexibility, and withstand long periods of operation without breaking. The cold-resistant performance of cables in low-temperature environments depends on the low-temperature resistance of the insulation and sheathing materials used. Ordinary PVC cable materials are prone to embrittlement and cracking during use, and their low-temperature performance does not meet these requirements.

[0003] A search revealed patent publication number CN110903573A, which discloses a PVC modified material, its preparation method, and uses. The modified PVC material comprises: 100 parts by weight of PVC resin; 20-40 parts by weight of polyurethane; 10-30 parts by weight of primary plasticizer; 1-20 parts by weight of secondary plasticizer; 1-20 parts by weight of liquid flame retardant; 20-50 parts by weight of solid flame retardant; 1-20 parts by weight of cold-resistant agent; and 1-20 parts by weight of clay. This invention utilizes polyurethane and a cold-resistant agent to improve cold and low-temperature resistance, and clay to improve the compatibility of system components and promote plasticization. However, the complex raw material composition complicates production procedures. During the extrusion and granulation process, the temperatures of the patented twin-screw extruder are 145-155°C, 150-160°C, 155-165°C, 160-170°C, 165-175°C, 170-180°C, 170-180°C, and 165-175°C, respectively; while the temperatures of the single-screw extruder are 115-125°C, 125-135°C, 125-135°C, and 130-140°C, respectively. The temperatures in each zone of the twin-screw extruder are higher than those in the general PVC cable material production process, which increases kinetic energy loss and costs during the production process.

[0004] Therefore, it is urgent to study a low-cost cold-resistant insulation grade soft polyvinyl chloride cable material. Summary of the Invention

[0005] The purpose of the present invention is to provide a cold-resistant insulating grade soft polyvinyl chloride cable material and a preparation method thereof, which solves the problems of poor cold resistance of existing soft polyvinyl chloride cable materials, high cost and complex preparation.

[0006] The present invention is achieved through the following technical solutions: The present invention discloses a cold-resistant insulating grade soft polyvinyl chloride cable material, which comprises, by weight: 100 parts of PVC resin powder, 10-30 parts of inorganic filler, 40-70 parts of plasticizer, 0.2-0.6 parts of processing aid A, 0.2-0.6 parts of processing aid B, 3-7 parts of stabilizer; The inorganic filler is active nano calcium carbonate.

[0007] Furthermore, the PVC resin powder is SG-3 type PVC resin powder.

[0008] Furthermore, the plasticizer is dioctyl terephthalate.

[0009] Furthermore, the processing aid A is stearic acid, and the processing aid B is polyethylene wax.

[0010] Furthermore, the stabilizer is a calcium-zinc composite stabilizer.

[0011] Furthermore, the inorganic filler is 12-16 parts.

[0012] The present invention also discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, which specifically comprises the following steps: Mix PVC resin powder, plasticizer, inorganic filler, processing aid A, processing aid B and stabilizer into a high-speed mixer at a mixing temperature of 100-150°C for 10-20 minutes to obtain a uniform mixture, which is then discharged into the feeding bin of the granulation process; The above-mentioned mixed material is fed into a two-stage extruder granulator composed of a twin-screw and a single-screw, and the heating temperatures of each section of the twin-screw granulator are 110±10℃, 115±10℃, 115±10℃, 110±10℃, 110±10℃, 110±10℃, 115±10℃, 120±10℃, and 120±10℃, and the head temperature is 150±10℃; the heating temperatures of each section of the single-screw granulator are 120±10℃, 130±10℃, and 130±10℃, and the temperatures of the screen changing zone and the head zone are 135±10℃ and 150±10℃, respectively. After extrusion granulation, cold-resistant insulation grade soft polyvinyl chloride cable material is obtained.

[0013] Furthermore, when the raw materials are mixed into the high-speed mixer, PVC resin powder and plasticizer are first added, and then calcium carbonate, processing aid A, processing aid B and stabilizer are added.

[0014] Furthermore, in the step of mixing the PVC resin powder, plasticizer, inorganic filler, processing aid A, processing aid B and stabilizer into the high-speed mixer, the mixing process is first carried out by low-speed stirring for 3-5 minutes at a stirring speed of 200-400 r / min, and then by high-speed stirring for 7-15 minutes at a stirring speed of 800-1200 r / min.

[0015] Furthermore, the temperature difference between two adjacent heating sections of the twin-screw granulator does not exceed 10°C.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a cold-resistant, insulating-grade soft polyvinyl chloride cable material. The material comprises, by weight, 100 parts PVC resin powder, 10-30 parts inorganic filler, 40-70 parts plasticizer, 0.2-0.6 parts processing aid A, 0.2-0.6 parts processing aid B, and 3-7 parts stabilizer. The inorganic filler uses activated nano-calcium carbonate, eliminating the need for other cold-resistant auxiliary plasticizers. With the addition of only one plasticizer (dioctyl terephthalate), the material meets the standard requirements for -40°C cold-resistant soft polyvinyl chloride cable materials for wires and cables. Conventional calcium carbonate forms micron-sized particles and is prone to agglomeration. However, the small particle size and large specific surface area of ​​activated nano-calcium carbonate improve compatibility with other components, resulting in a more uniform dispersion and enhanced tensile strength and crack resistance. Furthermore, nano-calcium carbonate, through finer dispersion and optimized interfacial compatibility, reduces plasticizer absorption, maintains the cable material's flexibility, and synergizes with the plasticizer to further inhibit low-temperature embrittlement. In addition, the high dispersibility of active nano-calcium carbonate can improve the microscopic pores of the PVC matrix, reduce internal defects of the material, thereby reducing the risk of partial discharge and improving dielectric strength and volume resistivity.

[0017] The present invention also provides a method for preparing cold-resistant, insulating-grade soft polyvinyl chloride cable material. The raw materials are mixed into a high-speed mixer. Under high-speed stirring and high-temperature conditions, the raw materials are uniformly mixed and initially plasticized, which is beneficial for the subsequent extrusion and granulation process and product performance stability. With this cable material formulation system and high-speed mixing process technology, the material undergoes initial plasticization during the high-speed mixing process and is then granulated through a two-stage extruder extrusion granulation process. The two-stage extruder consists of two parts: a high-speed, co-rotating twin-screw mixer in the first stage and a low-speed, single-screw extruder in a vertically orthogonal arrangement, forming a two-stage composite unit. The high-speed, co-rotating twin-screw mixer fully compresses, melts, disperses, and mixes the high-speed mixed material to achieve the purpose of plasticization, and then transports the material to the next stage. The low-speed single-screw extruder uses the friction and pressure generated by its rotation to transport the material processed by the twin screws toward the die head, providing a stable and continuous supply of material for subsequent granulation and molding. At the temperature designed for the twin-screw extruder of the present invention, the material is plasticized by the shearing elements and the material's self-friction, and the product performance meets the requirements. The material has already undergone preliminary plasticization during the high-mixing process, so the temperature in each zone of the twin-screw extruder is relatively low.

[0018] Furthermore, during the mixing process, the materials must be added in the order of PVC resin powder, plasticizer, calcium carbonate, and various processing aids. This is because the oil absorption value of calcium carbonate is much greater than that of PVC resin powder. If calcium carbonate and plasticizer are added to the high-speed mixer first, the calcium carbonate will quickly absorb the plasticizer, leaving the PVC resin powder added later to absorb only a small amount of plasticizer, resulting in uneven material distribution and subsequently affecting product performance. Therefore, PVC resin powder and plasticizer should be added first, followed by calcium carbonate and various processing aids, so that each material can evenly absorb the plasticizer and mix evenly.

[0019] Furthermore, in the step of mixing the PVC resin powder, plasticizer, inorganic filler, processing aid A, processing aid B and stabilizer into the high-speed mixer, the mixing process is first carried out by low-speed stirring for 3 to 5 minutes at a stirring speed of 200 to 400 r / min, and then by high-speed stirring for 7 to 15 minutes at a stirring speed of 800 to 1200 r / min. By alternating high and low speed stirring, the components are mixed more evenly, thereby further improving the overall performance of the cable material.

[0020] Furthermore, in the heating temperature of each section of the twin-screw granulator, the temperature difference between two adjacent sections does not exceed 10°C. Through more precise temperature gradient control, the material is guaranteed to be heated evenly during the extrusion process, preventing local overheating or overcooling from causing differences in cable material performance, and ensuring the stable quality of the final cold-resistant insulation grade soft polyvinyl chloride cable material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a process flow chart of the high-mixing process of the patented method for preparing cold-resistant insulating grade soft polyvinyl chloride cable material. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following is a further detailed description with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0023] The detailed description of the embodiment of the present invention provided in the following figures is not intended to limit the scope of the claimed invention, but merely represents a selected embodiment of the present invention. All other embodiments derived by those skilled in the art based on the figures and embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, so that a process, element, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to the process, element, method, article or apparatus.

[0025] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0026] Example 1 like Figure 1 As shown, the present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 12 parts of active nano-calcium carbonate, 45 parts of plasticizer, 0.5 parts of stearic acid, 0.5 parts of polyethylene wax, and 5 parts of calcium-zinc composite stabilizer are mixed into a high-speed mixer in the order of first adding PVC resin powder and plasticizer, then adding active nano-calcium carbonate, various processing aids and calcium-zinc composite stabilizer. The mixing temperature is 100° C. and the mixing time is 10 minutes to obtain a uniform mixture, which is then discharged into the feeding bin of the granulation process. The mixing process was carried out by first stirring at a low speed for 3 minutes at a stirring speed of 200 r / min, and then stirring at a high speed for 7 minutes at a stirring speed of 800 r / min.

[0027] The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0028] Example 2 The present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 14 parts of active nano calcium carbonate, 50 parts of plasticizer, 0.5 parts of stearic acid, 0.5 parts of polyethylene wax, and 5 parts of calcium zinc composite stabilizer are mixed into a high-speed mixer in the order of first adding PVC resin powder and plasticizer, then adding calcium carbonate, various processing aids and calcium zinc composite stabilizer. The mixing temperature is 100°C and the mixing time is 10 minutes to obtain a uniform mixture, which is then discharged into the feeding bin of the granulation process. The mixing process was carried out by first stirring at a low speed for 3 minutes at a stirring speed of 400 r / min, and then stirring at a high speed for 7 minutes at a stirring speed of 1200 r / min.

[0029] The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0030] Example 3 The present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 16 parts of active nano calcium carbonate, 55 parts of plasticizer, 0.5 parts of stearic acid, 0.5 parts of polyethylene wax, and 5 parts of calcium zinc composite stabilizer were mixed into a high-speed mixer in the order of first adding PVC resin powder and plasticizer, then adding calcium carbonate, various processing aids and calcium zinc composite stabilizer. The mixing temperature was 100°C and the mixing time was 15 minutes to obtain a uniform mixture, which was then discharged into the feeding bin of the granulation process. The mixing process was carried out by first stirring at a low speed for 5 minutes at a stirring speed of 300 r / min, and then stirring at a high speed for 10 minutes at a stirring speed of 900 r / min.

[0031] The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0032] Example 4 The present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 30 parts of active nano calcium carbonate, 70 parts of plasticizer, 0.6 parts of stearic acid, 0.6 parts of polyethylene wax, and 7 parts of calcium zinc composite stabilizer were mixed into a high-speed mixer in the order of first adding PVC resin powder and plasticizer, then adding calcium carbonate, various processing aids and calcium zinc composite stabilizer. The mixing temperature was 150°C and the mixing time was 20 minutes to obtain a uniform mixture, which was then discharged into the feeding bin of the granulation process. The mixing process was carried out by first stirring at a low speed for 5 minutes at a stirring speed of 400 r / min, and then stirring at a high speed for 15 minutes at a stirring speed of 1000 r / min.

[0033] The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0034] Example 5 The present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 10 parts of active nano calcium carbonate, 40 parts of plasticizer, 0.2 parts of stearic acid, 0.2 parts of polyethylene wax, and 3 parts of calcium zinc composite stabilizer are mixed into a high-speed mixer in the order of first adding PVC resin powder and plasticizer, then adding calcium carbonate, various processing aids and calcium zinc composite stabilizer. The mixing temperature is 100°C and the mixing time is 15 minutes to obtain a uniform mixture, which is then discharged into the feeding bin of the granulation process; The mixing process was carried out by first stirring at a low speed for 4 minutes at a stirring speed of 300 r / min, and then stirring at a high speed for 11 minutes at a stirring speed of 1000 r / min.

[0035] The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0036] Comparative Example 1 The present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 16 parts of heavy calcium carbonate, 55 parts of plasticizer, 0.5 parts of stearic acid, 0.5 parts of polyethylene wax, and 5 parts of calcium-zinc composite stabilizer are mixed into a high-speed mixer in the order of first adding the PVC resin powder and the plasticizer, then adding the calcium carbonate, the processing aids, and the calcium-zinc composite stabilizer. The mixing temperature is 100° C. and the mixing time is 10 minutes to obtain a uniform mixture, which is then discharged into a feeding bin for the granulation process. The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0037] Comparative Example 2 The present invention discloses a method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material, comprising the following steps: 100 parts of SG-3 type PVC resin powder, 8 parts of heavy calcium carbonate, 8 parts of active nano calcium carbonate, 55 parts of plasticizer, 0.5 parts of stearic acid, 0.5 parts of polyethylene wax, and 5 parts of calcium-zinc composite stabilizer are mixed into a high-speed mixer in the order of first adding the PVC resin powder and the plasticizer, then adding the calcium carbonate, the processing aids, and the calcium-zinc composite stabilizer. The mixing temperature is 100° C. and the mixing time is 10 minutes to obtain a uniform mixture, which is then discharged into a feeding bin for a granulation process. The above-mentioned mixture is fed into a two-stage extruder granulator consisting of a twin-screw and a single-screw. The heating temperatures of each section of the twin-screw granulator are 110°C, 115°C, 115°C, 110°C, 110°C, 110°C, 115°C, 120°C, and 120°C, and the head temperature is 150°C; the heating temperatures of each section of the single-screw granulator are 120°C, 130°C, and 130°C, and the temperatures of the screen changing and head zones are 135°C and 150°C, respectively. After extrusion granulation, cold-resistant insulating grade soft polyvinyl chloride cable material is obtained.

[0038] Performance Testing The various performance tests were performed on each embodiment according to the test method in Table 1 below, and the test results are shown in Table 2.

[0039] Table 1

[0040] Table 2

[0041] The same test methods were used to test the performance of the control examples. The test results are shown in Table 3.

[0042] Table 3

[0043] As can be seen from Table 2, the cold-resistant insulation-grade soft polyvinyl chloride cable materials of Examples 1-5 of the present invention all exhibit excellent performance.

[0044] As can be seen from Table 3, the cold-resistant insulating grade soft polyvinyl chloride cable material of Comparative Example 1 of the present invention uses ordinary heavy calcium carbonate, and the number of broken roots due to -40°C impact embrittlement performance is greater than 15, and the low-temperature performance is poor, which cannot meet the relevant standard requirements.

[0045] The cold-resistant insulating grade soft polyvinyl chloride cable material of comparative example 2 of the present application adopts ordinary heavy calcium carbonate and active nano calcium carbonate, and has poor low-temperature performance.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A cold-resistant insulating grade soft polyvinyl chloride cable material, characterized in that: Calculated by mass, including: 100 parts of PVC resin powder, 10-30 parts of inorganic filler, 40-70 parts of plasticizer, 0.2-0.6 parts of processing aid A, 0.2-0.6 parts of processing aid B, 3-7 parts of stabilizer; The inorganic filler is active nano calcium carbonate.

2. The cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 1, characterized in that: The PVC resin powder is SG-3 type PVC resin powder.

3. The cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 1, characterized in that: The plasticizer is dioctyl terephthalate.

4. The cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 1, characterized in that: The processing aid A is stearic acid, and the processing aid B is polyethylene wax.

5. The cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 1, characterized in that: The stabilizer is a calcium-zinc composite stabilizer.

6. The cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 1, characterized in that: The inorganic filler is 12-16 parts.

7. A method for preparing cold-resistant insulating grade soft polyvinyl chloride cable material, characterized in that: The specific steps include: Mix PVC resin powder, plasticizer, inorganic filler, processing aid A, processing aid B and stabilizer into a high-speed mixer at a mixing temperature of 100-150°C for 10-20 minutes to obtain a uniform mixture, which is then discharged into the feeding bin of the granulation process; The above-mentioned mixed material is fed into a two-stage extruder granulator composed of a twin-screw and a single-screw, and the heating temperatures of each section of the twin-screw granulator are 110±10℃, 115±10℃, 115±10℃, 110±10℃, 110±10℃, 110±10℃, 115±10℃, 120±10℃, and 120±10℃, and the head temperature is 150±10℃; the heating temperatures of each section of the single-screw granulator are 120±10℃, 130±10℃, and 130±10℃, and the temperatures of the screen changing zone and the head zone are 135±10℃ and 150±10℃, respectively. After extrusion granulation, cold-resistant insulation grade soft polyvinyl chloride cable material is obtained.

8. The method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 7, characterized in that: When mixing the raw materials into the high-speed mixer, first add PVC resin powder and plasticizer, then add calcium carbonate, processing aid A, processing aid B and stabilizer.

9. The method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 7, characterized in that: In the step of mixing the PVC resin powder, plasticizer, inorganic filler, processing aid A, processing aid B and stabilizer into the high-speed mixer, the mixing process is first carried out by low-speed stirring for 3-5 minutes at a stirring speed of 200-400 r / min, and then by high-speed stirring for 7-15 minutes at a stirring speed of 800-1200 r / min.

10. The method for preparing a cold-resistant insulating grade soft polyvinyl chloride cable material according to claim 7, characterized in that: The temperature difference between two adjacent heating sections of the twin-screw pelletizer does not exceed 10°C.

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