Union Dyeing Of Cotton/Woool Blended Textiles With Reactive Dyes

Cotton/wool blended fabrics are rapidly increasing in consumer interest for comfort, value and versatility. Cotton/wool blends combine durability, good moisture absorption and antistatic performance of cotton fabrics and the warmth, resilience, fullness of hand of wool fabrics. While the dyeing properties of the blends vary due to the different fiber structure, the conventional method of union dyeing requires reactive or direct dyes for cotton and acid or reactive dyes for wool in a two-bath process. Due to the complexity and waste of resources of two-bath process, one bath dyeing using one dye (reactive dyes) is studied as an alternative. However, the preferential dye uptake by wool and difficulty of effectively dyeing cotton and wool to the same shade using one-bath process lead to limited availability of cotton/wool blends.This topic is a project cooperated with enterprise, amid at effectively dyeing cotton and wool to the same shade by screening the new dyeing auxiliaries and dyeing process optimization research, providing scientific guidance to the replacement of auxiliary and dyeing process. And the new auxiliary and one-bath dyeing process would be applied for workshop production with satisfactory union-dyeing performance, as a result, the production efficiency improved while production costs and energy consumption reduced.First of all, we selected a series of trichromatic dyes from the existing workshop production reactive dyes by evaluating the dye percentage, K/S value of the two components and Q(value of the same color balance). The reason for the poor union shade was discussed as well. The result shows that the size difference in specific surface area and the dye uptake rate of cotton and wool fiber account for the poor union shade. Finally, the LY series of trichromatic dyes were selected as the subsequent dyeing dyes including LY Red BSF, LY Yellow3RF, LY Blue BRF.Secondly, series of HD-Y auxiliaries provided by HanDa Textile Co., Ltd.were applied to one-bath dyeing of wool fabrics, and the value of RE(resist effectiveness) shows that HD-Y001and HD-Y003are much more resist-effective. Considering the performance in improving the union-shade of the cotton/wool blends, combined with the solubility and the resist effectiveness to different dyes, HD-Y003was finally choose as the auxiliary in subsequent dyeing process.Then, the dyeing process optimization research was investigated by the single factor experiment, evaluated by the K/S value of the two components and Q(value of the same color balance). The optimum dyeing process as follows: the dosage of HD-Y003for shallow, medium and deep color is0.9%,0.7%,0.6%(o.w.f.) respectively; Na2CO3in dyeing stage is0.25g/L; electrolyte Na2SO4for shallow, medium and deep color is30,35-40,50g/L respectively:NajCO3in fixation stage for shallow, medium and deep color is10,12,14g/L respectively; dyeing at40℃for30minutes and then heat up by1℃/min to60℃for40min. Q(value of the same color balance) of the trichromatic dyed fabrics are well controlled to the range of0.9-1.1with excellent washing fastness. The optimum dyeing process used in color matching dyeing experiment suggested good performance as well.Industrial production experiment was carried out based on this laboratory process, There were some adjustments such as moderate increase of0.1-0.2%o.w.f. in HD Y003.The results showed satisfactory union-dying performance in industrial production which can meet the needs of normal production orders; gross profit for blended fabrics is three times as much as pure cotton fabric, and the gross margin is nearly15%higher. The new auxiliary and new process has brought significant economic benefits for the enterprise.Finally, the process in which dyeing-fixation one bath one stage was explored on the basis of the above process:the dosage of HD-Y003is1.0-1.2%(o.w.f.) respectively; fixation Na2CO3for shallow, medium and deep color is6,8,8g/L respectively, which is reduced by40-50percentage. The possibility of recycling of the dye bath was explored and the circulation dyeing process was determined by orthogonal experiments:the dosage of HD-Y003is1.2%(o.w.f.), electrolyte Na2SO420g/L and Na2CO32g/L. And the K/S value and washing fastness is as good as the above processes. This circulation process is not only a save of the water through recycling but also a save of resources and energy, and reduce the difficulty of wastewater treatment.