IMPROVEMENTS IN OR RELATING TO THE BONDING OF WORKPIECES AND APPARATUS FOR USE THEREIN

1,243,970. Boots &c. BRITISH UNITED SHOE MACHINERY CO. Ltd. 9 Dec., 1968 [9 Dec., 1967], No. 56120/67. Addition to 1,202,357. Heading A3B. [Also in Division B5] The method of the parent specification of coating a piece of sheet material, e.g., a shoe upper component, with heat-softenable adhesive in which the piece is sandwiched between a layer of adhesive and a carrier layer, heat and pressure are applied to bond the adhesive to the piece and carrier layer and the piece is separated leaving surplus adhesive on the carrier layer is modified by (a) directing a stream of hot air between the piece and the carrier layer as they are being separated, whereby to facilitate separation and (b) passing the coated pieces over a cooling surface to render the adhesive non-tacky so that successive coated pieces may be stacked on the top of another. As described a layer of adhesive on a backing layer 193, e.g. of paper coated with a release agent, together with the pieces to be coated and a carrier layer 310 are passed between heated pressure rollers 118, 120. A stream of hot air from a nozzle 354a is directed at the point where the carrier layer 310 is separated from the pieces and the backing layer 193 to facilitate the separation and to minimise stringing of the adhesive. The backing layer and pieces then pass over a cooling surface (Fig. 3) consisting of a tank 382 filled with liquid which is cooled by the refrigerating coil of a refrigerating unit 366. The cooled pieces are stripped from the backing layer 193 by a roller 388 and are stacked in a container 394.