Continuous Dyeing

The review concentrates on the period 1973‐79 and is restricted to fully‐continuous methods, i.e. semi‐continuous processes such as pad‐batch or pad‐roll are not considered. An indication of the major trends of development during this period is given. The most important section relates the form in which the substrate is dyed to the type of equipment used: topics include the continuous dyeing of (a) undrawn synthetic filaments in the gel state, (b) warp yams, (c) conventional woven and knitted fabrics, (d) carpets. Developments in low pick‐up techniques of application, such as foam‐padding, loop‐transfer and spray methods, as well as in fixation and washing processes, are discussed. A much shorter section on non‐aqueous methods follows. me large number of patents referring to continuous dyeing from organic solvents and dating mainly from early in the period covered by the review are mentioned briefly. The more promising recent development of the combined dyeing and mercerizing of cotton in liquid ammonia is given attention. The third section is concerned mainly with developments in dyes, auxiliaries and process sequences in continuous dyeing. Unlike the earlier sections, it is subdivided according to the major fibre types: wool and nylon, cellulosic fibres, polyester‐cellulosic blends. The concluding paragraphs reiterate the major themes, with an attempt to indicate possible future trends in continuous dyeing.