FERRAMENTA DE FENDA ANULAR PARA A EXTRUSAO DE MATERIAL SINTETICO TERMOPLASTICO

摘要

A nozzle assembly has an upstream part which transforms a solid thermoplastic-resin strand into an upstream tube section which is centered on an axis and flows axially. Formations inside this upstream part impart rotation about the axis to at least a portion of the material of the upstream tube section. This upstream tube section is then deflected by a distributor radially outwardly and then forced through a plurality of generally angularly equispaced radially extending throttle passages in a throttle ring. The individual solid streams issuing from this throttle ring are united into a downstream tube section that is passed axially through a downstream nozzle part which is also provided with formations that impart rotation about the axis to at least a portion of the material of the downstream tube section. Eventually the tube issues from the downstream end of the downstream nozzle part as a large-diameter tube suitable for blow molding.