PVC (Polyvinyl chloride) mainly plays the role of insulation and sheath in the cable, and the extrusion effect of PVC particles directly affects the use effect of the cable. The following lists the six common problems of PVC particles extrusion, simple but very practical!
01. PVC particles burning phenomenon during extrusion.
1. The screw is used for a long time, the screw is not cleaned, and the accumulated burnt matter is taken out; Remove the screw and clean it thoroughly.
2. Heating time is too long, PVC particles aging, scorch; Shorten the heating time, check whether there is a problem with the heating system, and timely maintenance.
02. PVC particles is not plasticized.
1. The temperature is too low; Appropriate increase can be.
2. When granulating, the plastic is mixed unevenly or there are difficult to plasticize particles in the plastic; The mold sleeve can be properly equipped with smaller, improve the pressure of the glue mouth.
03. Extrude uneven thickness and slub shape
1. Due to the screw and traction instability, resulting in uneven product thickness, due to the tension ring problems, easy to produce bamboo, mold is too small, or cable core diameter changes, resulting in thickness fluctuations.
2. Often check the traction, screw, and take-up tension device or speed, timely adjustment; The matching mold should be suitable to prevent pouring glue; Monitor outside diameter changes frequently.
04. Cable material extrusion pores and bubbles
1. Caused by local ultra-high temperature control; It is found that the temperature should be adjusted in time and strictly controlled.
2. Plastic caused by moisture or water; Found that should be stopped in time and net moisture.
3. Drying device should be added; Dry the material before use.
4. The wire core should be preheated first if it is damp.
05. Cable material extrusion fit is not good
1. Low temperature control, poor plasticization; Strictly control the temperature according to the process.
2. Mold wear; Reform or eliminate wear mold.
3. Low head temperature, plastic gluing is not good; Appropriately raise the head temperature.
06. PVC particles extrusion surface is not good
1. The resin that is difficult to plasticize is extruded without plasticization, resulting in small crystal points and particles on the surface, distributed around the surface; The temperature should be appropriately increased or the traction line speed and screw speed should be reduced.
2. When adding materials, impurities are mixed with the surface of impurities; When adding material, impurities should be strictly prevented from mixing, and impurities should be immediately cleaned up and the screw memory glue should be cleared.
3. When the cable core is too heavy, the pay-off tension is small, and the cooling is not good, the plastic surface is easy to wrinkle; The former should increase the tension, and the latter should reduce the traction line speed to ensure the cooling time.
Post time: Apr-03-2024