Importance

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Abstract

A supply of hollow plastic tubing is obtained from an extrusion and sizing apparatus, or from a supply of hollow tubing on a reel. The hollow tubing is provided at a predetermined speed to a tensioning device which imparts a tension in the hollow tubing and delivers it to a feeding point at one edge of the periphery of a rotating drum. The continuous hollow tubing is wound around the periphery of the drum at the one edge and it is forced axially on the periphery by a helical shoe overlying the periphery at the one edge. A bank of quartz lamps heats one side of the hollow plastic tubing just prior to reaching the feeding point, and another bank of quartz lamps heats the opposite side of the hollow plastic tubing at the one edge of the drum just after the tubing passes the shoe. The two heated surfaces are pressed together by the axial force exerted by the shoe, and are fused in side by side relation to form a cylinder having a wall consisting of spiral turns of the plastic tubing fused together.

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First Claim