Description
The recent trend in extrusion equipment has been toward more accurate drive systems. Tighter extrudate tolerances have required extruders, positive displacement melt pumps and belt or wheel pullers to use drives which offer improved long term accuracy and stable performance over varying loads. Whereas two to three years ago the common drive used was a simple SCR drive with armature feedback capable of 2-3% base speed regulation, today the extrudate tolerance associated with