| 摘要 |
An injection molding apparatus is of the screw in-line type and has a screw (1) rotationally and axially movable in an extrusion cylinder (2), and is used for injection-molding a high-nitryl resin. The screw (1) has the following features, namely a compression ratio set to a value of 1.8 to 2.5; lengths of the feed, compression, and metering sections set in the ratios of [1 to 1.5] : [1.8 to 2.8] : [1]; a depth T (unit:mm) of the groove, in the metering section, between its flight (1b) and the diameter D (unit: mm) of its cylindrical shaft (1a) set to T >/= 0.057D - 0.2; and a radius of curvature R (unit:mm) of the arcuate surface (1c) at a rear corner portion which is formed between the screw shaft (1a) and a flight (1b), in relation to the inner diameter D (unit: mm) of cylindrical shaft, set to R >/= 0.36D + 2.0. |
