Plastics tubes

Abstract

Abstract 1349843 Extruded reinforced tubes CREATORS Ltd 19 April 1971 [16 April 1970] 18317/70 Heading B5A [Also in Division F2P] A reinforced plastics tube comprises a wall 6 of soft PVC extruded from an annular die passage, having at least one reinforcing helix 19 of harder PVC extruded externally therearound and bonded by fusion thereto, and preferably partially embedded therein. The table wall 6 is extruded from an annular die outlet 4 and the helix 19 is applied to the wall 6, whilst still in a heat softened condition, from one or more extrusion outlets 18 which rotate around the annular die outlet 4. The outlet 18 is formed in a sleeve 14 which is rotated by the engagement of teeth 16, of a radial flange 15 thereof, by a driving claim 17, and the harder PVC is supplied to the outlet 18 from a crosshead feed, via a stationary annular distribution chamber 13. The tube wall 6 may be supported internally by air pressure admitted through die mandrel passages 7, 8. The helix 19 may be pressed into and partially embedded in the surface of tube 6 by a vacuum or pressure sizing operation on the tube moving away from the die.

Inventors

No inventors recorded.

Bibliographic Details