Troubleshooting: Extrusion

Defect:Black specks, Burning
Possible Causes:

1. Check temperatures
2. Check quality and material of construction for surfaces in contact with melt
3. Check for streamlined, low inventory die/adapter
4. Clean out all burned or foreign material from die, adapter, and extruder
5. Check that proper screw is installed

Defect:Dimensional Variation
Possible Causes:

1. Reduce screw speed

Defect:Pitting or Foaming
Possible Causes:

1. Further drying is required

Defect:Poor Impact and Physical Properties
Possible Causes:

1. Check stock temperatures

Defect:Rough Appearance
Possible Causes:

1. Check that proper screw is installed

Defect:Surging
Possible Causes:

1. Reduce screw speed
2. Eliminate screw cooling

Defect:Too Glossy
Possible Causes:

1. Reduce screw speed
2. Reduce barrel temperature
3. Check that proper screw is installed