PVC wire
DATE：2022/10/22 8:35:56 / READ： / SOURCE：This station
PVC wire
(1) The raw material for PVC filament extrusion molding is SG5 resin in suspension PVC as the main raw material, and a certain proportion of stabilizer, plasticizer, lubricant and other auxiliary materials are added according to the application conditions of the filament to form the raw material formula.See Table 9-6 for specific material formula. Supply time reference.
(2) Equipment conditions PVC monofilament extrusion molding production line is shown in Figure 9-6. The main equipment of the production line includes: single screw extruder, molding die, spinning plate, stretching device, hot water tank, winding device, etc. The structure and function of these equipment are basically similar to that of the equipment for PE filament extrusion molding.
Table 9-6 Raw Material Formula for PVC Monofilament Extrusion Molding Unit: Mass
Figure 9-6 Monofilament Extrusion Molding Production Line
1 - Extruder; 2 - Forming mould; 3 - Cooling water tank; 4.68 - TENSION DEVICE
57 - Hot water tank; 9 - Coiler
(3) Forming process
① See Chapter 4 for the mixing process conditions and requirements of raw materials.
② The process temperature of the raw material extrusion plasticizer barrel is 90~110 ℃ in the feeding section, 120~140 ℃ in the plasticizing section, and 150~170 ℃ in the homogenizing section.
③ The temperature of forming die is 170~180 ℃.
④ The stretching temperature is 95~100 ℃. The stretching ratio is about 4 times.
(4) Quality requirements
① The diameter of PVC wire is (0.24.3) mm; The rope wire is 4 (0,22+0.03) mm
② Appearance quality of silk
a. The finished product is silky, smooth and soft, with uniform color. b. Impurities, bubbles and cracks are not allowed.
c. It is not allowed to have disordered wires, untensioned wires and broken wires, which shall not be less than 500mm long. ③ See Table 9-7 for the physical and mechanical properties of the wire.
Table 9-7 Main Physical and Mechanical Properties of PVC Monofilament
(5) Key points of process operation
① When extruding and plasticizing raw materials for forming monofilament, perforated plate and filter screen shall be added at the front end of the barrel, with mesh size of 40/80 mesh, 1~3 layers of PVC and 2~4 layers of polyethylene and polypropylene.
② The accuracy of the spinneret plate shall be maintained during the work, and the working surface of the spinneret hole shall be kept smooth, free of scraps and scratches. Knock is not allowed during disassembly, and handle gently to prevent deformation.
③ The water temperature in the cooling tank shall be controlled at 20~30 ℃, the liquid level shall be 30~50mm from the spinneret, and the running length of the wire in the water shall be greater than 1m. The air cooling temperature of PVC monofilament is 40~60 ℃.
④ The heating temperature during wire drawing shall be controlled below the melting point of the raw material, and the temperature can be as high as possible. The tensile temperature of PVC monofilament is 95~100 ℃
⑤ The tensile ratio of the wire shall be determined according to the strength required by the work. The tensile ratio of different plastics is 8~11 for polyethylene, 5~8 for polypropylene, 3~5 for polyamide (nylon) and 3~6 for polyvinyl chloride.
⑥ The drawn finished silk shall be subject to annealing heat treatment to eliminate the internal stress and reduce the shrinkage of the silk. The heating temperature during heat treatment shall be controlled below the heating temperature during wire drawing. No heat treatment is required for wires without special requirements
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