Introduction:
Cotton is the backbone of the world's textiletrade. It has many qualities and countless end uses, which make it one of themost abundantly, used textile fibres in the world. It is a seed hair of plantof genus gossypium, the purest form of cellulose found in nature. However,cotton is one of the most problematic fibres as far as its general wetprocessing or dyeing is concerned. Quite frequently, the problems in dyedcotton materials are not due to the actual dyeing process but due to some latentdefects introduced from previous production and processing stages. Often, theroot-cause of a problem in the dyed material can be traced as far back as tothe cotton field.
The dyeability variations are cotton obtainedfrom different sources. It has been suggested that the substrate should beobtained from a single source, wherever possible, in order to keep thedyeability. Variations than other, those dyes should be selected for dyeingwhich are less sensitive to dyeability variation. In dyeing, if resultant shadefor a dye mixture passes the quality examination after its first dyeing, theproduct is called a right-first-time product. The process producing theright-first-time product is thus called a right-first-time process: one that iseconomical because it consumes the least energy, labor, and time etc. Toproduce a right-first-time product, process control is essential for dyeingand, to enable this, many modern dyeing control systems have been developed.Unfortunately, errors in the dyeing operation will still sometimes occur.Therefore employing a low-sensitivity recipe in dyeing may be an alternativeapproach. Should dyeing errors occur, the less sensitive the recipe is to sucherrors, the more chance there is that the resultant shade will successful.
About the Authors:
The authorsare textile scientists at Pakistan Council of Scientific & Industrial Research(PCSIR) Lab complex, Karachi.
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