IMPROVED 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 re- spect to highly-viscous materials so as to effectively elim- inate the phenomenon of bursting upon movement of the snuff- back 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 condi- tions 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.