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**Twin-Screw Pipe & Profile Extrusion** · Critical

      # Die Lip Plate-Out & Waxy Drool Build-Up

      

डाई के मुंह पर वैक्स व प्लेट-आउट जमना

      
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## 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.

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## 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.

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**Evidence status: technical synthesis.** This diagnosis is a technical starting point. Confirm the cause with controlled checks before changing production.

      

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