EXCHANGER FOR SHIEVE FOR EXTRUDING MACHINE

摘要

A screening apparatus for molten plastic material flowing from an extruder comprising a housing mounted on the extruder and having a feed channel for flow of the plastic material therefrom and a slide member mounted for slidable movement in the housing with a clearance therebetween. The slide member contains replaceable screen elements adapted for being positioned in the path of flow of the plastic material flowing from the extruder to effect screening thereof. In order to seal the clearance between the slide member and the housing to prevent outflow of plastic material therefrom, a flange is mounted on the housing to surround the slide member with a gap therebetween. This permits normal free-sliding movement of the slide member in the housing. The flange contains cooling channels to permit flow of a coolant to cool plastic material in the gap and solidify the plastic material to prevent outflow of plastic material from the gap. The flange is mounted on the housing by thermal insulation which prevents cooling of the housing upon cooling of the flange.