GB613068A - Improvements in and relating to dyeing fibres - Google Patents

Abstract

Loosely piled fibres and fibrous materials are dyed at a temperature below the boiling temperature of the dyebath; and during the dyeing process bubbles of a gas which is noncondensible and non-soluble at the working temperature are introduced into the bath. The materials are subjected to movement to dislodge <PICT:0613068/IV (c)/1> <PICT:0613068/IV (c)/2> adhering gas bubbles. The gas, e.g. air, may be mixed with the dye liquor before its entry into the dyeing apparatus. Apparatus is described (see Fig. 4) in which the material is placed between the two perforated plates 23 and 24 and dye liquor is circulated by the propeller 28 past the pipe 29 through which air is injected, through the plate 23, the material, and the plate 24, and back to the propeller through the perforated spiral pipe 25. At intervals the direction of flow of the liquid is reversed to dislodge adhering bubbles. Apparatus is described also in which the goods are placed in a drum 31, Fig. 6, having perforated walls, ribs 40 and partitions 34, and which rotates in the dyebath 32. Air is blown into pipe 38 and this injects dye liquor from the pipe 37 together with air bubbles into the drum 31, from which it returns to the injector through the pipe 37. Other apparatus is described in which a fabric is passed in zig-zag fashion through a dyebath provided with a series of air injector nozzles along the bottom of the bath and a series of squeeze rollers above the level of the liquid. Other apparatus is described in which a fabric is treated in piled condition and in endless length. Specification 436,875 is referred to.