| 摘要 |
PURPOSE: To realize the injection molding in which the length of a contained fiber if kept as long as possible at the injection molding of fiber reinforced resin product by charging reinforcing fibers and a thermoplastic resin by a method wherein the compression ratio of a screw and its apparent shearing speed are set to be not more than the predetermined values in a fully flighted screw. CONSTITUTION: A screw 22 is a fully flighted one, the compression ratio with which is set to be not more than 4 and the apparent shearing speed of which is set to be not more than 100sec<-1> . The ratio of the lengths of three zones, which are formed by dividing the length ranging from the end to the tip of the screw 22 into three parts or concretely in a feed zone 221, a compression zone 222 and a metering zone 223, is 1.5-2.5:0.8-1.5:1. Further, the ratio L/D or the ratio of the length L of the screw to the diameter D of the screw is preferably be 20 or more. Furthermore, the pitch between the flights of the screw is preferably 1-1.3 times as large as the diameter D of the screw. |
