A pigment mixing method and apparatus

摘要

A method for mixing pigment material in powder or granular form with a plastics material in similar form for extrusion or injection moulding comprises delivering the plastics material downwardly through a vertical throat (34) formed by a duct (28) into a barrel (1) of extrusion or injection moulding apparatus. The pigment material is delivered downwardly into the flow of plastics material through a nozzle (38) located axially centrally in the throat (34). The nozzle (38) is positioned just above a pair of mixing screws (10) located in the barrel (1) and the plastics material and pigment material are delivered into the barrel (1) for subsequent mixing, melting and compression for delivery through a nozzle (4) in flowable particulate form.