Ambient-temperature Bleaching and Reactive Dyeing of Jute: The Effects of Pre-treatment, Bleaching, and Dyeing Methods

It is shown that it is possible to carry out pre-treatment, bleaching, and dyeing of jute yarn at ambient temperature to produce dyed yarn comparable with that produced by conventional processing techniques. Ambient-temperature bleaching on alkali-treated yarn without washing produces the best bleaching effect since it produces a good whiteness/brightness index and retains the maximum tenacity. If ambient-temperature bleaching is done on alkali-treated yarn, the yarn thus produced has the maximum affinity to a substitution type of reactive dye and also produces the maximum colour yield. For the addition type of reactive dye, no pre-treatment is required, and only ambient-temperature-bleached yarn shows the maximum colour yield. In all cases, ambient-temperature-bleached yarn gives better dyeing performance than conventionally hot-bleached yarn. For cold-brand reactive dyes, the warm-bicarbonate method of dyeing is not suitable for jute, and the silicate method of dyeing gives better dyeing performance tha...