摘要 |
In the extrusion of plastic pipe wherein the pipe is in a self supporting but semi-molten state on exiting a die orifice, the inner surface of the extrudate is cooled by a device which applies a suction for establishing flow of a cooling fluid which contacts the inner surface of the extrudate. In a further embodiment the flow of cooling fluid established for cooling the extrudate additionally cools a cavity within a mandrel of the die orifice.
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