Twin-Screw Pipe & Profile Extrusion · Critical

Die Lip Plate-Out & Waxy Drool Build-Up

डाई के मुंह पर वैक्स व प्लेट-आउट जमना

What the defect looks like

Continuous deposition of sticky wax or oxidized material on the outer die exit lip. Within 2 to 4 hours of continuous extrusion, the build-up breaks off, creating deep drag lines, roughness, and matte streaks on the product.

Root-cause mechanism

Thermodynamic incompatibility under high die entry shear stress. In unplasticized or rigid PVC, low-molecular-weight external lubricants (polyethylene wax exceeding 0.30 PHR) or volatile paraffin fractions in inferior CPW separate from the molten compound stream and condense upon contacting the cooler metal exit lip.

This diagnosis is a technical starting point. Confirm the cause with controlled checks before changing production.