Annular extrusion die - with rotating shear ring to provide pumping and shearing action, used esp. for high mol. PVC

摘要

An annular extrusion die incorporates a rotating shear ring. The ring may be carried either by the die core or by the outer member and is either helically grooved or operated opposite a helically grooved portion of the other die component. The ring and groove formation act to pump the working material and to shear it. This makes the die particularly suitable for high molecular weight PVC.