Polyurethane prepared in extruder section only of plasticiser - from directly metered components or preliminary mixtures

摘要

Prodn. and moulding of a polyurethane is effected by feeding the separate components into the extrusion section of a continuously operating multi-screw extruder, esp. a planet roll extruder, in either solid or liq. form; the components are directly supplied in metered quantities and observing the correct temp. into this extrusion section, where they are mixed and plasticised and kept for sufficient time for the polymerisation process to occur. Pref. reacting components are supplied separately to the extrusion section while non-reacting components are mixed and then supplied as a mixt.