Method of covering a pipe, especially a steel pipe, and other metallic articles with thermoplastic synthetic material
AssigneeHoesch Werke Aktiengesellschaft
InventorFritz Muckenheim
Life of this patent
Estimating the term…
Abstract
A method of covering a metallic pipe and other metallic articles with thermoplastic synthetic material, especially polyethylene according to which the synthetic material is in the form of a foil leaving an extruder helically wound upon a heated-up rotating steel pipe. The thus applied foil is by means of a roller pressed onto the pipe to be covered. Prior to the foil contacting the steel pipe, the foil is passed over the pressing roller through an angle range of from 25.degree. to 50.degree..
Claims3
A method of covering metallic articles and pipes, especially steel pipes, with thermoplastic synthetic material, which includes in combination the steps of:
- first heating the pipe having an outer peripheral surface to be covered to a temperature of from 170.degree. to 190.degree. C while simultaneously rotating said pipe at a circumferential speed of from 10 to 100 meters per minute, feeding said thermoplastic synthetic material in the form of a foil onto the heated outer peripheral surface of said rotating pipe while winding said foil helically around said pipe and with a roller pressing said roll against said heated outer peripheral surface, said foil immediately prior to its contact with said pipe also being arched over the roller in an angle range of only from 25.degree. to 50.degree. on the roller avoiding air occlusion.
Dependencies are inferred from the claim text.