Causes of Poor Plasticization in Cable Extrusion Process

What leads to poor plasticization during cable extrusion? The details are as follows:

Manifestations of Poor Plasticization

1. Toad-skin-like appearance on the plastic layer surface;
2. Low temperature readings on control instruments, with actual measurements confirming insufficient heat;
3. Dull plastic surface with micro-cracks or unplasticized particles;
4. Visible seam line indicating poor polymer fusion.

Causes

1. Inadequate or improperly controlled temperature settings;
2. Presence of hard-to-plasticize resin particles in the material;
3. Improper operation - excessive screw and haul-off speeds preventing complete plasticization;
4. Non-uniform material mixing during compounding or inherent material quality issues.

Solutions

1. Strictly maintain process-specified temperatures; increase when readings are low;
2. Optimize processing speeds:
3. Reduce screw rotation speed by 10-15%;
4. Decrease haul-off speed to extend residence time.