Research on microwave pad dyeing process for wool fabric

Abstract

Purpose

This paper aims to study microwave pad dyeing process for wool fabric. Influences of various dyeing process conditions including galactomannan dosage, urea dosage, sodium bisulphite dosage, pH value, microwave irradiation power, treating time and cold batching time before microwave fixation on K/S values were analysed. The colour yield, fixation and levelness were compared between microwave fixation and cold batching fixation.

Design/methodology/approach

Colour yield (K/S values) was calculated using a Datacolor SF650 colour measuring and matching instrument (10° standard observer, CIE D65 light source Measuring; Datacolor, USA) and was used to determine the depth of the shade of dyed wool fabrics. Levelness of dyeing was evaluated also using the Datacolor SF650 colour measuring and matching instrument by measuring average deviation (S), range (P) of the maximum and the minimum for lightness (L), chroma (C) and hue (h), and balanced colour difference (ΔE) at 20 specified uniform locations on the wool fabrics. The colour difference was calculated as per the equation ΔE=(ΔL2+Δa2+Δb2)1/2 as appearing in the Experimental section. Fixation was determined using a Datacolor SF650 colour measuring and matching instrument by measuring ratio the of K/S for wool fabrics that were rinsed, washed, neutralised and then dried, and wool fabrics that were dried after fixation without washing. The pH of the padding solution was evaluated using a PHSJ-4A PH meter (Datacolor, USA). SEM analysis was done on JEOL JSM-5600LV machine (JEOL Ltd, Japan).

Findings

This study is based on application of microwave technology in the processing of silk.

Originality/value

It was found in laboratory experiments that uniform dyeing and deeper colour can be achieved throughout the microwave pad dyeing process for wool by using galactomannan. The novel process could reduce the dyeing time and the energy consumption of the traditional cold pad-batch dyeing process for wool fabric.

Citation

Zhao, X. (2017), "Research on microwave pad dyeing process for wool fabric", Research Journal of Textile and Apparel, Vol. 21 No. 4, pp. 263-275. https://doi.org/10.1108/RJTA-03-2017-0008