GB964298A - Improvements in producing metal to metal bonds with structural adhesives - Google Patents

Abstract

964,298. Jointing. ASSOCIATED ENGINEERING Ltd. May 21, 1963 [May 22, 1962], No. 19678/62. Heading B3V. A method of making metal to metal bonds with structural adhesive comprises placing the parts together with an adhesive therebetween and supplying current to the parts, which are used as electrodes, to generate heat in the adhesive without appreciably raising the temperature of the parts. In a preferred embodiment a H.F. generator is isolated from and capacitatively coupled to one or both of the parts by a low loss dielectric material to safeguard the generator against a short-circuit should the parts touch. The adhesives may be mixed synthetic resins, rubber and resin, phenolic and polyvinyl formal powder, or thermoplastic adhesives. Accelerated evaporation of any solvents contained in the adhesive may be achieved by rapid local heating of the parts prior to the bonding operation. Gauze or an unwoven mat of " Terylene " (Registered Trade Mark), or nylon may be inserted between the parts to improve the loss factor of the adhesive and also reduce the risk of the parts touching when pressure is applied during heating. The method may be used to bond metal brackets, stiffeners, fixing lugs which may or may not be plastic-coated to pressings made from plastic-coated metal sheet or metal studs, brackets to the steel side of plasticcoated sheets. Alternatively, the adhesive may be resistance heated by applying an appropriate voltage from a 50-cycle mains supply.