Hybrid bleaching of jute yarn using hydrogen peroxide and peracetic acid

Abstract

An alternative eco-friendly method of bleaching of jute fibre and yarn has been developed using peracetic acid as bleaching agent and it is found that the treatment produces satisfactory whiteness with minimum loss in tensile properties. Comparative study on bleaching of jute using these two bleaching agents (hydrogen peroxide and peracetic acid) clearly demonstrates that hydrogen peroxide bleaching produces 5-8 grades higher whiteness in HUNTER Scale but peracetic acid bleached fibre and yarn show better retention of tensile strength after bleaching. Partial bleaching of jute has also been carried out using 25%, 50% and 75% (normal dose) of both bleaching agents separately and their whiteness indexes as well as tensile strength are evaluated. In both the bleaching processes, whiteness increases with increase in concentration of bleaching agents and tensile strength retention decreases. It is also clear that for any particular percentage of bleaching agent, whiteness index is more in peroxide bleached sample, while tensile strength is more in case of peracetic acid bleached samples. Hence, hybrid bleaching has been carried out using both the bleaching agents (peracetic acid and hydrogen peroxide) by two-step bleaching process so that the synergistic effect can produce higher whiteness with high retention of tenacity. Moreover, the sequence of bleaching, i.e. peracetic acid followed by hydrogen peroxide or vice versa has also been studied in detail. It has been found that the hybrid bleaching of jute using peracetic acid followed by hydrogen peroxide produces better whiteness with high retention of tensile strength. The hybrid bleaching of jute using 75% peracetic acid followed by 25% hydrogen peroxide produces the best result.