Method and apparatus for making helical plastic members, and the members produced

摘要

Helical plastic members are formed by rotating an extrusion die while extruding a filament in a generally horizontal direction just above a tank of liquid. The plastic helix so formed is cooled and solidified in the liquid. A mandrel in the liquid can be used to guide the helix downwardly, and the helix is removed from the tank with extraction rollers. As a variation, the tank can rotate relative to a fixed extrusion nozzle which extrudes the plastic horizontally just above the rotating liquid in the tank.