Commencement of a second melt stream of a second moldable material from the auxiliary injection unit is initiated upon the sensed condition related to the injection of the first melt stream being detected at a preselected value.

A process is described for stabilizing the melt flow rate and melt tension of ethylene-carbon monoxide interpolymers with a hindered phenol antioxidant.

A melt stream flow path is formed in the fixed part (20) of an injection moulding tool (12).

A method and apparatus of controlling commencement of an injection of a melt stream of moldable material from an auxiliary injection unit.

Other forms of a gasless nozzle (334, 336) have a configuration for confining and imparting mechanically an angular momentum to the molten stream to break it up.

The prepolymer compositions can be extruded at low temperature through a multi-annular die and surrounded by a co-extruded concentric melt stream which forms a tube with good structural integrity.

A sensor is placed in an injection molding system to sense a condition related to an injection of a first melt stream of a first moldable material provided by a primary injection unit.