Apparatus for and method of making a heating structure

Abstract

Abstract 885,131. Laminates. GOODRICH CO., B. F. April 23, 1959 [April 24, 1958], No. 13889/59. Drawings to Specification. Class 140. [Also in Group XI] A laminated sheet-like structure for electrical heating, e.g. such as used for preventing accumulation of ice on the leading edges of aerofoils, is made by bonding together to form a unit, by curing, layers of thermo-setting plastic heat-conducting electrically-insulating material, with an electric heating element disposed between the layers, and then bonding one of the layers to a protective skin by a final cure. The unit may be formed by first bonding one of the layers to a sheet of electrical resistance metal, e.g. aluminium bronze, phosphor bronze, nickel - chromium, nickel - chromium - iron or nickel-copper alloys from which a predetermined pattern may then be removed, e.g. by a photoengraving process, to leave the electric heating element on the layer, and then bonding another layer on the assembly by a second cure. The layers may be formed of a blend of phenolformaldehyde resin with butadiene-acrylonitrile copolymer rubber and vulcanizing ingredients for the latter, and sheets of heat-resistant woven fabric, e.g. of glass fibre, may be embedded in the layers. The fabric and metal sheets may be given a priming coating of the plastic before being bonded together. The unit may be cured flat, e.g. in an evacuated mould having a flexible cover, in an autoclave, and then perforated to provide for venting, bent to conform to a curved protective skin, e.g. of stainless steel, or aluminium alloy, and bonded to the latter by curing in an evacuated rubber bag in an autoclave, or in a mould in which pressure is applied by numerous rigid balls, as described in Specification 885,132; this apparatus can also be used for bonding the structure to the leading edge of an aerofoil. Attaching strips of aluminium alloy may be adhesively bonded to the edges of the completed structure. Instead of making the electric heater element as described above, it may be made by looping preformed wires or strips. Specifications 654,669 and 850,339 also are referred to.

Inventors

No inventors recorded.

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