| 摘要 |
570,808. Rubber threads. UNITED STATES RUBBER CO. Aug.'12, 1943, No. 13040. Convention date, Aug. 29, 1942. [Class 70] Ribbons of separable rubber threads are prepared by extruding an aqueous dispersion of rubber from a plurality of orifices into a liquid coagulant, containing in suspension flocculated tack-preventing particles, such as talc or bentonite clay, bringing the coated filaments into side-by-side contact, drying and vulcanizing. In an example a latex dispersion, preferably containing a stiffening agent such as 2.2-di- (p - - hydroxy phenyl) propane, is extruded through multi-jet nozzles N, Fig. 1, into a coagulating bath containing 50 parts of acetic acid, 50 parts of water, 10 parts of talc and 1.5 parts of oleic acid, the coagulant being circulated and agitated by means of a pump 29 and a system of rakes 42, stirrers, scrapers 38 and baffles. Each rubber filament T acquires a thin coating of flocculated talc before passing over a power-driven roller 14, the top of which is slightly above the level of the coagulant so that the filaments form ribbon R, the threads being held together by a talc bond. These ribbons, after passing over rods 15 and round drum 16, have excess liquid removed by doctor blades 19. After being stretched by rolls 20 and 21 and spaced by combs 25, the ribbons travel on conveyer belt 23 through the drier and vulcanizer. Other flocculating agents such as stearic acid, cetyl alcohol, aliphatic alcohols, mineral, animal or vegetable oils may be added to the coagulating bath in place of the oleic acid. |
