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The winch dyeing process involves the movement of fabric, while the dye liquor remains stationary. The dye bath is heated through the heating coils within the front compartment to a maximum temperature of 95-98 degrees Celsius. The winch dyeing process has a high specific liquor ratio of around 1:20 to 1:40.
Using hard water in the wet process can cause problems such as the formation of scale in boilers, reactions with soap and detergents, reaction with dyes, and problems due to Iron. Water hardness can be removed by the boiling process, liming process, sodalime process, base exchange process, or synthetic ion exchange process.
Cationization of cotton enables salt free dyeing and enhances the dyeability of the substrate with anionic dyes such as reactive dyes and direct dyes. Water and salt consumption are one of the major problems in the dyeing especially cotton which leads to substantial environmental impact with extra time and cost. Secondly washing off the ...
Also called direct dyes, substantive dyes are employed for cellulose-based textiles, which includes cotton. The dyes bind to the textile by non-electrostatic forces. In another classification, azo dyes can be classified according to the number of azo groups. Trypan blue is an example of a direct dye, used for cotton.
Dye-sublimation printing (or dye-sub printing) is a term that covers several distinct digital computer printing techniques that involve using heat to transfer dye onto a substrate. The sublimation name was first applied because the dye was thought to make the transition between the solid and gas states without going through a liquid stage.
Vat dyes are a class of dyes that are classified as such because of the method by which they are applied. Vat dyeing is a process that refers to dyeing that takes place in a bucket or vat. The original vat dye is indigo , once obtained only from plants but now often produced synthetically.
In contrast to direct dyes, wool and leather goods are dyed by the process of ion exchange, exploiting the cationic nature of proteins near neutral pH. The development of substantive dyes helped make mordant dyes obsolete. [2] Substantive dyes are set in a slightly basic or neutral environment at temperatures close to boiling point.
The common dyeing process of cotton yarn with reactive dyes at package form is as follows: The raw yarn is wound on a spring tube to achieve a package suitable for dye penetration. These softened packages are loaded on a dyeing carrier's spindle one on another. The packages are pressed up to a desired height to achieve suitable density of packing.