The five common problems of PVC cable material extrusion are quickly collected and very practical!
The five common problems of PVC cable material extrusion are quickly collected and very practical!PVC (polyvinyl chloride) mainly plays the role of insulation and exterior decoration in the cable. The extrusion effect of PVC cable material directly affects the use effect of the cable and also affects the customer's desire to buy. The following Tianjin PVC cable material manufacturers list five common problems of PVC cable material extrusion, simple but very practical!
1. Scorch phenomenon when PVC cable material is extruded
The mold outlet has large smoke, strong odor and crackling sound; there is particle scorch on the plastic surface; there are continuous bubbles at the meeting place.
what reason? How to improve?
1. The screw is used for a long time, the screw is not cleaned, and the accumulated char is brought out; the screw can be removed and cleaned thoroughly.
2. The heating time is too long, the plastic is aging and scorch; shorten the heating time, check the heating system for problems, and timely repair.
2. Poor extrusion and plasticization of PVC cable materials
The plastic surface has toad skin phenomenon, the surface is black, and there are tiny cracks or small particles that have not been plasticized. There is an obvious trace at the meeting place.
what reason? How to improve?
1. The temperature is too low; just raise it appropriately.
2. During granulation, the plastic is mixed unevenly or there are particles in the plastic that are difficult to plasticize; the mold sleeve can be properly equipped with a smaller one to increase the pressure of the glue outlet.
3. The screw and traction speed are too fast, the plastic is not completely plasticized; slow down the speed properly, extend the heating and plasticizing time, and improve the plasticizing effect.
4. Material problem; refueling.
3. The surface of PVC cable material is not good
what reason? How to improve?
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 linear speed and screw speed should be reduced.
2. Impurities are mixed in when feeding, and there are impurities on the surface. Impurities should be strictly prevented when feeding. If mixed impurities are found, the machine head should be cleaned immediately and the glue in the screw should be discharged.
3. The surface of the mold bushing diameter is not smooth or notched, or there are plastic decomposition products accumulated on the die mouth, which makes the surface have traces; when selecting the mold, you should carefully check whether the surface of the wire diameter is smooth, and appropriately reduce the temperature of the die mouth. Deposits should be removed immediately at the die opening.
4. The cable core is too heavy, the pay-off tension is small, and the plastic surface is easy to wrinkle when the cooling is not good; the former should increase the tension, the latter should reduce the traction line speed to ensure the cooling time.
4. Uneven thickness and slub shape
what reason? How to improve?
Due to the instability of the screw and traction, the thickness of the product is uneven. Due to the problem of the tension ring, it is easy to produce slubs, the mold is too small, or the outer diameter of the cable core changes greatly, causing thickness fluctuations.
Always check the tension device or speed of the traction, screw, and take-up and pay-off line, and adjust it in time; the matching mold should be suitable to prevent the glue from being poured; the change of the outer diameter is often monitored.
5. Cable material extruding air holes and bubbles
what reason? How to improve?
1. It is caused by the local super high temperature control; if it is found, the temperature should be adjusted and controlled strictly in time.
2. The plastic is caused by damp or water ingress; if it is found, the damp material should be stopped and drained in time.
3. A drying device should be added; the material is dried before use.
4. The core of wire should be warmed up first.
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