GB1022105A - Improvements relating to the manufacture of footwear - Google Patents

Abstract

1,022,105. Making shoes. C. & J. CLARK Ltd. April 26, 1962 [May 16, 1961], No. 30119/63. Divided out of 17771/61. Heading A3B. The stresses and strains set up in shoe uppers are relaxed after lasting by a hot wetting treatment of the upper, whilst still on the last, and this treatment is preferably followed immediately by a heat-setting of the upper which also dries it out. The casted shoe uppers are treated, preferably, for from ¢ to 5 minutes with water in liquid, vapour, mist, steam or superheated steam form, and at temperatures up to 90‹C., e.g. 30‹-40‹C., or even 120‹C. Wetting or penetrating agents may be present, if desired, e.g. non-ionic or weakly ionic materials such as the dioctyl ester of Sodium Sulphosuccinic acid, condensation products of di-octyl phenol and ethylene oxide, or more strongly ionic substances, e.g. methyl didecyl benzyl trimethyl Ammonium Chloride among others. Subsequent heat-setting uses hot-air or dielectric, radiant, fluidized-bed, or infra-red heat the preferred procedure comprising heating the upper to a surface temperature of 100 to 160‹C, cooling for 60 seconds and then heating to 80 to 150‹C. Before slipping the upper may be cooled by a cold air stream. Grouped shoe components are loaded on to a track alongside paired right and left foot lasts and carried in 9 second through a temperature gradient and conditioner sequentially at stations along the track the following operations are then performed, stiffener insertion, pulling once, toe-lasting, seat casting, shank fitting, the pliability of the leather established by the pre-conditioning treatment of the uppers being preferably maintained by optional humidifying tunnels, shoe-bottom drying, pounding and roughening and sole-adhesive application. The stress relaxation conditioning is then effected in a humidifying tunnel and concurrent heat-setting on the upper and activation of the sole-adhesive effected in a further tunnel. Finally a sole is attached, the shoe is cooled in a tunnel, a heel is attached and the shoe slipped from the last.