Improvements in or relating to processes and apparatus for insulating tubes and the like against the action of heat and cold and atmospheric influences

摘要

480,354. Coating tubes &c. with plastic compositions by extrusion. LENOIR, J. July 16, 1936, No. 19761/37. Convention date, July 16, 1935. [Classes 70 and 87 (ii)] Tubes, metal bars, &c. are coated with a material that provides thermal insulation and protection against atmospheric action by working up the material in uniform particle size or powder form with up to 25 per cent by weight of a binder to form a difficultly mouldable plastic mass and then applying the mass to the tube &c. by extrusion under a pressure of from 10 to 150 atmospheres absolute. The material may comprise kieselguhr, asbestos, cork, wood flour, felt, fireclay, wood charcoal, ash, &c. and the binder may comprise waterglass and water. The plastic mass is applied to the tube &c. by an apparatus comprising two cylinders 1 having pistons 2 and connected by an elbow 10 to a common die aperture 6 which is interchangeable. The tube 3 is advanced by rollers 4 through an inlet 5 and the die 6. The rollers 4 may be geared to the pistons 2. The cylinders 1 can be swung about spigots 9 for filling or alternatively the pistons may be adapted to be swung aside. In a modification, the cylinders 1 are arranged at an angle to one another. The Specification as open to inspection under Sect. 91 comprises also an apparatus having a single cylinder 1 arranged at right-angles to the direction of travel of the tube 3 and provided with a filling opening closed by a removable cover. This subject-matter does not appear in the Specification as accepted.