Screw and barrel wear is critical in all plasticating applications whether is it extrusion, injection molding, and blow molding, plus twin screw extrusion.
Excessive screw and barrel wear can cause instable throughput or recovery on reciprocating screws, increased melt temperature and reduced plasticating rates.
Some of the causes of excessive wear are:
- Screw straightness
- Barrel straightness
- Barrel alignment to the gearbox
- Screw/barrel concentricity
- Screw speed
- Screw flight to Barrel liner compatibility
- Polymer being process
- Fillers in the polymer
- High headpressure