Effect of ultrasound on dyeing of wool fabric with acid dye

Abstract

Wool fiber strength and handle is damaged by holding for prolonged periods at normal dyeing temperatures (98°C). Lower dyeing temperatures can be employed to color wool whilst reducing damage caused to the fiber. However, these lower temperature dyeing processes often have a long dyeing time and/or require the addition of chemicals to achieve adequate dye exhaustion and migration. The use of ultrasonic irradiation was used to reduce dyeing times and temperatures whilst increasing dye migration and fastness. It has used 30 kHz frequency level, effective power of 120 and 350 W heating power in ultrasonic machine. In this work, wool dyeing was carried out on single jersey knitted fabric using an acid dye with and without ultrasonic irradiation at 60, 70, and 80°C. Dye exhaustion was measured using UV/visible absorbance of the dye bath before and during the dyeing cycle. For the measurement of nodal/anti-nodal point of energy, at 60, 70, and 80°C dyeing was done in open bath of ultrasonic machine with and without sonication at high liquor ratio. To compare the dye uptake (%) at high/conventional process, sample was dyed at 95°C. Optical and scanning electron microscopy were used to measure the diameter and surface changes of the fiber, respectively. Wash and rub fastness was measured on the dyed fabrics after rinsing and drying. Ultrasonic irradiation during the dyeing of wool caused an increase in the dye exhaustion rate for acid dye. This change in rate is believed to have been caused by a reduction in the viscous boundary layer of liquor surrounding the fiber present in an ultrasonic irradiated environment. An increased dye migration due to cuticle cracking and fiber swelling was not deemed to have occurred as wet fiber diameter was not changed by submersion in the dye liquor in the presence of ultrasound and no surface cracking was evident in scanning electron microscopy images. Some cuticle structure changes occurred with turning up or ripping off of the cuticle tips evident. Both wash and rub fastness were improved for ultrasonically dyed fiber with dyeing temperatures of 70 and 80°C being suitable for the low-temperature dyeing of wool.

Selective Modifications of Sheep Wool Usable in Non-Textile Applications

“…The findings of Nazmul Islam et al [10] about the impact of US methods complement the conclusions of the above-mentioned authors [8,9]. Samples of woolen knitted fabric were dyed with acid dye without and using ultrasound with (30 kHz) at 60, 70, and 80 • C. Applying the US frequency of 30 kHz, no damage to the fiber surface was observed; however, the US method increased the rate of dye uptake.…”

“…The findings of Nazmul Islam et al [10] about the impact of US methods complemen the conclusions of the above-mentioned authors [8,9]. Samples of woolen knitted fabr were dyed with acid dye without and using ultrasound with (30 kHz) at 60, 70, and 80 °C Since most authors focus on the following wool dyeing process after washing, they evaluate the effect of US washing according to the quality of dyeing of the wool cleaned in the US bath.…”

“…The subsequent implosion of the microbubbles causes a shock wave capable of tearing off microparticles of dirt from the fiber. Several researchers focused on the use of this principle and investigated the possibilities of scouring wool with the support of US methods [8][9][10][11]. The experiments were carried out on a laboratory scale (Table 1), but no information is Keratin chains can be grouped into a three-dimensional right-handed α-helical conformation or a planar β-sheet conformation, always with some proportion of an amorphous portion.…”

An efficient ultrasonic-assisted bleaching strategy customized for yak hair triggered by melanin-targeted Fenton reaction

“…The high velocity jetting liquid emerged from the collapse of bubbles, accelerates the mixing function on the boundaries between fiber and solution, thereby promoting the transfer of Fe 2+ and H 2 O 2 to the fiber surface [30] . The slight relief of the cuticle scales and sufficient swelling of yak hair fiber in the ultrasonic medium is favourable for the penetration of bleaching components (Fe 2+ and H 2 O 2 ) to the fiber interior [31] , enhancing the adsorption between Fe 2+ and colour impurities, and increasing the H 2 O 2 concentration around colour impurities. Meanwhile, the “hot spot” produced by the bubbles breakage induces localized high-temperature and high-pressure phenomenon.…”

Eco-Friendly Pretreatment to the Coloration Enhancement of Reactive Dye Digital Inkjet Printing on Wool Fabrics

“…It not only caused severe damages to wool fibers but also generated great pollution to our environment. − To overcome the pollution difficulties, ultrasound, plasma, and enzymatic treatment and ionic liquid treatment research studies have been carried out. Ultrasound and plasma can achieve low energy consumption and no pollution. − However, the imperfection of the equipment and the instability of the process make industrial applications difficult. Although ionic liquids have been extensively studied in wool treatment as a green solvent, the high cost limited their application. − Resin finishing is an effective method to improve wettability, but the treated fabrics become thicker and feel hard. , H 2 O 2 was used as a green oxidant in textile bleaching processing due to its features of green, less corrosion, and easy operation. , Wang et al selected H 2 O 2 to improve the surface wettability and moisture transfer properties of wool.…”