GB763965A - Improvements in or relating to the treatment of moving lengths of material with liquids - Google Patents

Abstract

763,965. Coating yarns; coating webs. TOOTAL BROADHURST LEE CO., Ltd. March 5, 1954 [Dec. 18, 1952], No. 32077/52. Class 140. A length 1 of material to be coated or treated with a substance dissolved, dispersed, or emulsified in a liquid, is passed between two rolls 2 and 3, to one or both of which the liquid containing the treating substance is fed at a rate greater than that necessary for the intended rate of take-up by the material, e.g. by a pump 5 from a mixing tank 4 to a reservoir 6 one wall of which is constituted by the roll 3. The excess liquid is returned, e.g. through a hopper 13 and pipe 14, to tank 4 which is fed with concentrated liquid at a uniform rate such that the rate of feed of the contained treating substance is the desired rate of take-up by the material, e.g. 1, by a metering pump 21 from tank 20, and is also fed with a diluting liquid from tank 22 the supply of which is controlled by a liquid level detector in tank 4 to keep the contents of the tank at a fixed volume. Thus the concentration of treating substance in tank 4 will be reduced if the rate of take-up by the material is too great. The pipe line leading from tank 20 to metering pump 21 may include a feed pump delivering at a rate greater than that of the metering pump, and a branch pipe leading from the pipe line just before the metering pump and returning to the tank, to cause circulation of the concentrated liquid. The reservoir 6 to which the treating liquid is fed from tank 4 may be the upwardly facing nip between two rollers lying side-by-side. The treating substance may be dye or size and the diluent, hot water. The material treated may be one or more filaments, yarns, or threads, ribbon or web of fabric or paper.