Snuffback valve for hot melt adhesive

摘要

A snuffback valve assembly comprising a snuffback valve element having a tapered frusto-conically disposed downstream end portion for moving aerodynamically with respect to highly-viscous materials so as to effectively eliminate the phenomenon of bursting upon movement of the snuffback valve element from the closed to opened positions, and an upstream end portion which comprises an annular portion disposed perpendicular to the axis of the valve element, and a sharp-cornered region, for disrupting the flow parameters of the viscous material and for maintaining vacuum conditions within a valve chamber so as to prevent stringing of the viscous material when the valve element is moved from the opened to closed positions.