Injection molding machine

Abstract

A partial reflux injection function partis provided according to which resin R at the front side of a screw head portionis injected into the metal moldto fill the metal moldwith the resin R in synchronization with the refluxing of a predetermined amount of the reflux resin Rm to be used as a part of the resin R to the screw body partside at the rear side of the screw head portionthrough the inner side of the screw head portionand/or the outer periphery side of the screw head portion. A control function is provided that sequentially performs a plasticization step Wito rotate the screwin the heating cylinderto thereby subject the resin in the heating cylinderto a plasticization processing; an injection step Wito allow, after the completion of the plasticization step Wi, the screwto move forward to thereby inject, into the metal mold, a part of the plasticized resin R accumulated at the front side of the screw head portionof the screwto fill the metal moldwith the resin; and a plasticization promotion step Wito allow, after the completion of the injection step Wi, a part of the remaining part of the accumulated plasticized resin R to be refluxed as the reflux resin Rm to the rear side of the screw head portion