Mixer insert for thermoplastic and unreacted elastomeric materials - esp for boundary layers of centrally-fed film blowing heads

摘要

A device for intercrossing passages for mixing in the boundary layers close to the walls of the feed channels of moulding tools for thermoplastic and unreacted elastomeric materials, has at its inlet side, directed towards the flow, a circular cutter dividing the inlet into a core channel and an outer annular channel, the stream of material dividing into a core flow with an annular flow surrounding it. The annular channel is divided in the circumferential direction into converging, and in the radial direction into correspondingly widening passages which open into channels. At the end of the mixing insert these channels unit at an outlet cutting edge into a new core channel. The inlet core channel is divided into passages which cross offset to them, the passages of the inlet annular channel, and open into channels which diverge in the circumferential direction and converge in the radial direction uniting to form a new annular channel enclosing the core channel. Device ensures an absolutely constant flow section throughout the length of the mixer. The operating details of the insert are easily produced on a miller with a dividing head, as well as assembled, dismantled and cleaned.