Vented injection molding machine screw and vent type injection molding machine incorporating the screw

摘要

PROBLEM TO BE SOLVED: To provide a vent-type injection molding machine which prevents the backflow of a material in the feed zone and the shortage of the material in the metering zone and is improved in plastication capacity.;SOLUTION: In the screw of the vent-type injection molding machine which is incorporated rotatably and forward/backward movably into a heating cylinder 9, spiral material feed grooves 6a and 6b are formed on the periphery of the surface of the screw shaft 3 by two flights 4 and 5. Material damming parts 7a and 7b are formed in the material feed grooves of the vent zone V. One or more small grooves 8a and 8b for the passage of the material which feed the material to the metering zone M are formed in the flight in the vicinity of the damming parts. Only a position opposite to the material feed opening 11 of the heating cylinder 9 is constituted of a single flight in the flight 4 located in the feed zone S.;COPYRIGHT: (C)2006,JPO&NCIPI