GB290519A - Improvements in or relating to the manufacture of shoes - Google Patents

Abstract

290,519. British United Shoe Machinery Co., Ltd., Mellerio, L. P., and Lund, W. J. Nov. 16, 1926. Stiffeners.-Thermoplastic stiffeners for boots and shoes consist of blanks charged with thermoplastic material which is capable of losing its thermoplasticity under suitable treatment. For instance, synthetic resins may be incorporated cold in a pulp of fibrous material prior to that material being felted in a paper making machine. On the other hand cloth or other fibrous material may be charged with the stiffening agent or mixture by impregnating the same with a solution of the agent or mixture in a volatile solvent or with an emulsion or suspensicn of the agent in a liquid, and then drying the impregnated material. Instead of a synthetic resin being used as the impregnated material, a thermoplastic mixture containing it may be applied to a sheet of fibrous material already charged with an ordinary thermoplastic stiffening compound. A still hot sheet of fibrous material impregnated with ordinary thermoplastic material may be passed over or in contact with a block of synthetic resin so that a coating of the resin is taken up by the fibrous material and chilled. The synthetic resin as powder may be dusted on a still hot sheet of thermoplastic material. Other materials than synthetic resin may be used. Drying oils amalgamate readily with resinous and like materials and diminish the thermoplasticity as oxidation or drying advances and by the use of well known drying accelerators. A marked change of thermoplasticity may be obtained by a minimum of heat treatment. Again ordinary resinous stiffening agents may be dusted over while still tacky with slaked lime which causes an appreciable loss of thermoplasticity under the above conditions. The invention is not restricted to treatment of toe puffs prior to incorporation in the shoe. A hot puff stitched into an upper might be coated with synthetic resin. In such a case the heating to which tho shoe would be subjected to for lasting and other operations would serve to initiate the curing of the synthetic resin. Specifications 18174/13, 2023/15, 112,663, [Class 17(i), Boots and shoes, Apparatus for making &c.]: 114,398, 125.027, 135,555, 135,806; 178,939 [Class 17(i), Boots and shoes, Apparatus for making &c.]; 197,351; 206,438. 210,161; 217,983, [Class 17(i), Boots and shoes, Apparatus for making &c.]: 236,600, 236,988, 262,838. 277,719, and 281,771 are referred to.