Patent ID: 9050741
Filing Date: 2015-06-09
Classification: B29C,B29K,B29L

Abstract:
1. A method for cleaning an extrusion head involved in extrusion of thermoplastic material expelled or extruded from an extrusion nozzle as a tubular preform, said method comprising: embracing the tubular preform from outside directly after exiting the extrusion nozzle by at least two rib-shaped partly circular pressing elements; and moving the at least two partly circular pressing elements in a radial direction to embrace and briefly deflect and upset the tubular preform without impeding a continuous flow of the tubular preform as the tubular preform exits the extrusion nozzle so that deposits adhering on both sides in a proximate region of an exit gap of the extrusion nozzle stick to the tubular preform for transporting the deposits away from the exit gap by the tubular preform which acts as a cleaning element.