Method of modifying corrugated or ribbed pipe to have a smooth outer wall
AssigneeCorma Inc.
InventorManfred A. A. Lupke
Life of this patent
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Abstract
Annularly or helically ribbed or corrugated semi-rigid thermoplastic pipe is modified to have a smooth outer wall. The ribbed or corrugated pipe is passed through a heated sleeve to squash and smooth the outer profile of corrugated pipe or bend over ribs of ribbed pipe and mold a smooth outer skin of the pipe. Apparatus for forming the modified pipe includes a travelling mold tunnel for the production of ribbed or corrugated pipe and a smoothing sleeve downstream thereof. The smoothing sleeve has a heater to heat it sufficiently to mold the smoother outer skin.
Claims13
A method for modifying profile pipe to form double-walled thermoplastic pipe having a substantially smooth outer surface and a substantially smooth inner surface comprising passing a heated softened profiled pipe having a smooth inner surface and a profiled outer surface having a projecting profile of diameter greater than a desired outer diameter of pipe to be formed past means for deforming the profile to correspond to the desired outer diameter of modified pipe to be formed, the profiled pipe being heated sufficiently for molding the profile to form a smooth pipe outer surface corresponding to the diameter of the sleeve.
Dependencies are inferred from the claim text.