INJECTOR

摘要

The axial dimension of an injector (31) is decreased, inserting/removing work of a screw (20) is facilitated, and the qualities of a molding are enhanced. The injector has a heating cylinder (17), the screw (20), and a driver. The screw (20) has a main body portion (45a), and a plasticization portion provided with flights (53) formed to project from the outer circumferential surface of the main body portion (45a). Assuming the screw stroke is S, the effective length of screw is L, and a value obtained by dividing the sum of the screw stroke S and the effective length L of screw by the screw stroke S is an index e, the index e is set to satisfy a relation 2.0<e<4.5. Even if the screw (20) is shortened, resin can be melted well. Consequently, the axial dimension of the injector (31) is decreased.