Patent ID: 6234659
Filing Date: 2001-05-22
Classification: B29C

Abstract:
A plasticating apparatus operable to masticate, plasticate, and devolatilize synthetic resinous material while preparing the synthetic resinous material for injection into a mold cavity which shapes the material, said apparatus comprising:a barrel having a longitudinal screw-receiving bore, a distal end, a feed opening communicating with said bore to admit synthetic resinous feed material, a discharge opening communicating with said bore at said distal end to deliver material to a mold, and a vent opening disposed intermediate said feed opening and said discharge opening to exhaust liberated gases;a screw having a root and a protruding first helical screw flight positioned in said screw-receiving bore and includinga first stage communication with the feed opening and operable within the barrel to receive, masticate ands substantially completely plasticate synthetic resinous material,a second stage communicating with the vent opening and the discharge opening, said second stage including a vent area of increased channel depth communicating with said vent opening;a surge suppressor disposed intermediate said first and said second stages, said surge suppressor operable to suppress surges of plasticated material occurring during an injection molding cycle, accumulate plasticated material during the surges, and dispense the accumulated plasticated material downstream between surges; andsaid surge suppressor further including a reservoir area of increased channel depth and an integral protrusion of said root of said screw, said protrusion disposed downstream of and adjacent to said reservoir area, said protrusion comprising a radially outwardly extending annular ring radially spaced from said bore to define a restricted annular space.