Patent ID: 6270703
Filing Date: 2001-08-07
Classification: B01D,B29C

Abstract:
A method of forming a filtration apparatus for an injection molding machine, the injection molding machine including a screw housed within a bore for generating molten polymer, the method comprising the steps of:axially extending a tip member from the screw, the tip member having radially extending upstream and downstream flanges positioned axially apart from each other;encircling a filter around the tip member for filtering the molten polymer;slidably positioning an annular ring member within the bore and encircling the tip member between the upstream and downstream flanges, the ring member capable of slidably engaging the downstream flange for directing the molten polymer through the filter as well as slidably engaging the upstream flange for preventing back flow of the molten polymer past the upstream flange; andpositioning an end stop within the bore capable of engaging and preventing movement of the ring member past the end stop while allowing the downstream flange of the tip member to be translated forwardly therepast to simultaneously space the upstream and downstream flanges apart from the ring member for allowing the molten polymer to bypass the filter for purging contaminants filtered from the molten polymer.