Melt distribution block and extrusion die

Abstract From the Canadian patent

A melt distribution block for feeding melt through an extrusion die to an extrusion passage. The melt distribution block has a generally annular body with, inner, outer, front and rear faces. The front and rear faces include a series of flow, divider channels therein extending generally radially inwardly from an inlet and, terminating in a plurality of feed spirals. The feed spirals curve radially inwardly, from the flow divider channels to encircle the inner face and narrow toward a radially inwardly disposed end. The feed spirals on the front and rear spaces curve in respectively the same direction. An inlet port extends into the outer face, and fluidly communicates with the inlet of …