Injection Moulding Machines

An injection moulding apparatus for producing injection moulded articles of two or more colours or of two or more synthetic plastic materials has a plunger (31) mounted for axial movement in a barrel (32) to which the two or more different materials, or material of two or more different colours is fed. The plunger (31) is formed with axially extending passageways (33) to convey one of the plastics materials an injection chamber (35), and with additional passageways or grooves (39) to convey a second material to the injection chamber, the arrangement of passageways and/or grooves being such as to provide a predetermined distribution of the plastics materials in the chamber (35) thereby to produce an article having a predetermined colour or material distribution.