Patent GB-414692-A (GB)
Title: Improvements in or relating to the manufacture of fireproof and waterproof fabrics and yarns
IPC: B65G15/38
Filed: 1933-02-02
Abstract: Mineral fibres such as asbestos, silica, glass and slag wool, are subjected in a closed vessel first to the action of a vacuum and then to pressure, which may be pulsating, accompanied by circulation of an aqueous dispersion of rubber.  The product may p  be subsequently vulcanized.  The fibres may be in the form of laps, felts or yarns would in bobbins, spools, hanks or packets. The yarn may have a metal wire or vegetable fibre core which may itself be already impregnated with rubber or may be a composite yarn of mineral and vegetable fibres, e.g. ramie.  The material may be pretreated with a wetting agent such as a solution of an alkaline metal silicate, or with a stabilizing agent such as sodium carbonate solution.  The rubber dispersion may be vulcanized latex.  After impregnation, the yarn &c. may be maintained in a humid atmosphere containing the vapours of an anti-coagulating agent and may be rotated slowly to facilitate complete impregnation.  After impregnation, the rubber may be coagulated by acetic acid, formic acid, alum, boric acid or ammonium phosphate.  Vulcanizing, accelerating or activating agents, e.g. zinc stearate, may be applied in solution or powdered form, or boric acid, asbestos or glass powder may be used to increase the incombustibility of the treated yarn.  An external coating of latex which may contain powdered asbestos, may be applied by leading the impregnated yarn from the bobbin through a bath of latex and then vertically upwards so that the added latex runs down the yarn to impart a smooth coating.  The product may be used for making flexible jointing material e.g. washers. Specifications 338,381, [Class 120 (iii)]; 344,414, 405,311, 405,312, and 405,313, [all in Group V], are referred to.ALSO:Mineral fibres such as asbestos, silica, glass and slag wool, are subjected in a closed vessel first to the action of a vacuum p  and then to pressure, which may be pulsating, accompanied by circulation of an aqueous dispersion of rubber.  The product may be subsequently vulcanized.  The fibres may be in the form of laps, felts or yarns wound in bobbins, spools, hanks or packets. The yarn may have a metal wire or vegetable fibre core which may itself be already impregnated with rubber or may be a composite yarn of mineral and vegetable fibres, e.g. ramie.  The material may be pre-treated with a wetting agent such as a solution of an alkaline metal silicate, or with a stabilizing agent such as sodium carbonate solution.  The rubber dispersion may be vulcanized latex.  After impregnation the yarn &c. may be maintained in a humid atmosphere containing the vapours of an anticoagulating agent and may be rotated slowly to facilitate complete impregnation.  After impregnation the rubber may be coagulated by acetic acid, formic acid, alum, boric acid or ammonium phosphate.  Vulcanizing, accelerating or activating agents, e.g. zinc stearate may be applied in solution or powdered form, or boric acid, asbestos or glass powder may be used to increase the incombustibility of the treated yarn.  An external coating of latex, which may contain powdered asbestos, may be applied by leading the impregnated yarn from the bobbin through a bath of latex and then vertically upwards so that the added latex runs down the yarn to impart a smooth coating.  The product may be used for making flexible jointing material, e.g. washers. Specifications 338,381, [Class 120 (iii)], 344,414, [Group IX], 405,311, 405,312, and 405,313 are referred to.