SCREW AND INJECTION APPARATUS

摘要

It is intended to reduce the axial dimension of injection apparatus and realize homogeneous melting of molding material and enhancing of molded item quality. Screw (20) has a plasticizing area including main body part (45a) and flight (53) provided so as to protrude from the outer circumferential surface of the main body part (45a). In a given zone of the plasticizing area, there is provided a groove-depth setting region. In the groove-depth setting region, when the diameter of molding material is referred to as d1 and the depth of groove (67) provided along the flight (53) referred to as t1, the ratio of groove depth t1 to diameter d1, ?1, satisfies the relationship 1=?1=1.5. In the groove (67), individual pellets are advanced rolling abreast along the groove (67). As pellet aggregation is prevented, no solid bed would occur.