Patent GB-1139521-A (GB)
Title: Improvements relating to laminates and methods of producing the same
IPC: B29C43/30
Filed: 1966-01-18
Abstract: 1,139,521. Flattened cylindrical laminate; moulding building elements. H. A. FROMSON. 18 Jan., 1966, No. 2363/66. Headings B5A and B5N. [Also in Divisions B3 and C7] A method of forming a laminate comprises, providing an impervious ductile tube 11 expanded and filled along part of its length with a deformable mass of core material 12, and passing the filled section of the tube through a shaping device, e.g. rollers 18, to shape and collapse the filled tube to an extent sufficient to form a laminate comprising a core and a casing therefor, the cross-sectional area of the filled tube section being reduced by the shaping device, and the core material being squeezed therein and consequently spread rearwardly into an unfilled section of the tube. In one apparatus, Fig. 1, for carrying out the method a strip 11 of flat metal tubing is fed from a coil 13 and between guide rolls 17. The front end of the strip is expanded to form a tube by fluid, e.g. air, pressure, and a quantity of core material 12 inserted in the expanded tube section. Alternatively the material 12 is used to expand the strip. The front end of the tube is then closed by crimping and fed via rollers 18, and feed rolls 26 to cutting blades 27 where the filled shaped tube is cut into laminates 10. As the tube is advanced by the feed rolls 26 it is shaped by rolls 18 which results in core material being spread rearwardly into an unfilled section of the tube. The rolls 17 apply pressure to the tubing and the core material so that the core material is fed to the rolls 18 in a uniform manner and no voids occur. The rolls 17 are advanced by hydraulic cylinders 20 as the quantity of core material decreases. When the core material 12 is of heat-softenable material the tube may be heated by a gas burner 24, and the tube and core material heated by an element 25, setting of the core material being effected after shaping by spraying with a cooling medium from sprayheads 23. Rolls 22 maintain the shape of the shaped tube until the core material is set. When the core material is of a thermosetting material heat is applied after shaping to set the core material. When the core material is of powdered metal this is sintered by heating after shaping. The tube material may be metal, e.g. lead, copper, aluminium or stainless steel, or a metal alloy, e.g. aluminium alloy, or plastics, and the core material may be plastics, e.g. polyethylene, plastics reinforced with glass fibres, thermosetting or thermoplastic plastics, metals, metal alloys, cements, or powdered metal. The tube material may be in the form of a flattened tube, with or without a pair of longitudinal ribs, or two strips welded together along their edges. In a second embodiment the tube is fed vertically and, when a powdered core material is used, is also vibrated. In a third embodiment, Fig. 7, the tube is formed by shaping a length of ribbon stock 35 and welding the edges together, e.g. by high-frequency, inductive, or heli-arc welding, and the core material is inserted via a feed pipe 38 and is pressed forward by a spring- loaded plate 42. In any embodiment the rolls 18, 41 may be replaced by several rolls or by a fixed drawing die to produce laminates of various shapes. The completed laminate may be used as panelling, e.g. for ships, aircraft, or buildings, or as boat or car body parts, or for heat insulation, or may be bent and its edges welded to form a tube.