The Undesirable Phenomenon and Solution of PVC Cable Material Extrusion
The surface of the die sleeve bearing diameter is not smooth or notched, or there are plastic decomposition products accumulated at the die opening, causing traces on the surface; When selecting the die, carefully check whether the surface of the bearing diameter is smooth, appropriately reduce the die temperature, and immediately remove the deposits found at the die opening.
Scorching Phenomenon of 1. PVC Cable Material Extrusion
The smoke at the outlet of the mold is large, the smell is strong and there is a crackling sound; the plastic surface has particles of scorched matter; there are continuous bubbles at the joint.
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. The heating time is too long, the plastic is aging and scorched; shorten the heating time, check whether there is any problem with the heating system, and repair it in time.
2. PVC cable material extrusion plasticization poor
The plastic surface has toad skin phenomenon, the surface is black, and there are tiny cracks or small particles that are not plasticized. There was a clear mark at the joint.
1. The temperature is too low; it can be increased appropriately.
2. When granulating, the plastic is mixed unevenly or there are particles that are difficult to plasticize in the plastic; the mold sleeve can be appropriately matched smaller to increase the pressure of the glue outlet.
3. The screw and traction speed is too fast, and the plastic is not completely plasticized; slow down the speed appropriately, extend the heating and plasticizing time, and improve the plasticizing effect.
4. Material problems; changing materials.
3. PVC cable material extrusion surface is not good
1. It is difficult to plasticize the resin in the absence of plasticization extrusion, resulting in the surface of small crystal spots and particles, distributed around the surface; should be appropriate to increase the temperature or reduce the traction line speed and screw speed.
2. Impurities are mixed in during feeding, and there are impurity bumps on the surface; During feeding, impurities should be strictly prevented from mixing. If impurities are found to be mixed, the head should be cleaned immediately and the glue in the screw should be drained.
3. The surface of the die sleeve bearing diameter is not smooth or has gaps, or there are plastic decomposition products accumulated at the die opening, causing traces on the surface; When selecting the die, carefully check whether the surface of the bearing diameter is smooth, appropriately reduce the die temperature, and immediately remove the deposits found at the die opening.
4. 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, the latter should reduce the traction line speed to ensure the cooling time.