GB1493169A - Sheathing hoses - Google Patents

Abstract

1493169 Forming split insulating hose IRBIT HOLDING AG 5 Aug 1975 32709/75 Heading B5A [Also in Division F2] In forming a longitudinally split sheathing hose having an inner foil 5 (Fig. 8) and an outer foil 7 with a mass of foam plastics material 5 sandwiched therebetween a preformed tube of foil 5 is fed via a guide tube 12 (Fig. 6) to the tip of a mandrel 20 and the outer foil is fed via a guide nozzle 13 to form an annular space around the inner foil 5 and foam material is fed via tube 28 to the annular space. A wiper 26 having holes 51 permits the foam material to trickle into the annular space between the foils and the material is foamed to fill the space by energy source 18 (e.g. an infra-red heater). In an alternative embodiment (Fig. 5, not shown) the wiper 26 is a disc with a serrated outer periphery. After the foaming the tube passes a cutter 22 which slits the foam so as to form a split sheathing. The outer foil may have overlapping edges in which case a deflector guide (31, Fig. 2, not shown) is provided in front of the cutter to lift and deflect the overlapping edge to avoid the cutter. The deflector or some other means may be used to apply adhesive to the overlapping edge. The mandrel is preferably perforated and supplied internally with compressed air to assist in the movement of the inner tubular foil over the mandrel and also to supply air to the inner tube at the tip of the mandrel to open it up for feeding on to the mandrel. The split sheathing is particularly useful as thermal insulation for pipes the outer foil then being of asbestos with a coating of a fire-protective paint on the outside.