Stanley ICI Mixer

A turbine mixing head patented by ICI in 1955 [1, 2] enabled polyethylene pipe manufacturers to meet appropriate pipe standards when feeding pellet blends of natural polyethylene and carbon black masterbatch into the pipe extruder. Until then it was necessary to use the more expensive pre-compounded material. The turbine mixers were used by at least two large polyethylene pipe producers until being superseded by CTM, and at a later date, becoming unnecessary in some cases when price distortions and the polymer supply situation produced a switch back to extrusion of pre-compounded materials. 

The turbine mixing heads consisted of alternate sets of fixed and moving teeth made by machining slots around the periphery of round discs externally for the rotor and internally for the stator. The rotor formed a screw extension and the stator a matching barrel extension. 

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