Comparison of conventional and ultrasonic method for dyeing of spunbond polyester nonwoven fabric.

Nonwoven spunbonded polyester has wide applications for both household goods and home furnishings and their usage has continually been growing. Nowadays, coloration of nonwoven fabrics is performed using conventional methods. Conventional polyester dyeing is an energy-intensive process as the dyeing is carried out above 120 °C to obtain efficient diffusion of dye. Furthermore, these high temperatures may cause some harmful effects on delicate nonwoven structures. Ultrasound assisted textile dyeing is an alternative method of conventional dyeing of textile materials, providing energy saving by reduced process temperature and time, lower consumptions of auxiliaries with increased dyeing efficiency. This paper focuses on comparing the conventional (high temperature (HT) and carrier dyeing) and ultrasonic dyeing of nonwoven spunbonded polyester fabrics to investigate the effect of ultrasound energy on dyeing performance. Experimental results indicated that highest or comparable dyeing performance can be achieved with ultrasound dyeing at lower temperature (85 °C, 60 min.) without carrier as compared to carrier dyeing (100 °C, 60 min.) and HT dyeing (130 °C, 60 min.), providing an increase of dye depth depending on the dye concentration and basis weight of the fabric. It was evidently seen that highest basis weight of fabric (107 g/m2) used in this study exhibited greater color yield for each dye concentrations (K/S value of 4.90 at 0.2% dye concentration) as compared to conventional ones. The effect of ultrasound energy on reductive washing and fastness properties were also evaluated.