Colorfastness properties of dyed, reduction cleared, and soft ened poly(lactic acid) fabrics

Softeners are usually applied to fabrics, including those made from polylactic acid, to improve hand and to reduce friction between fiber/fiber and fiber/metal during production. Commercially available softeners of different hydrophilicity, ionicity, and chemical type were applied to poly(lactic acid) fabric that was dyed to a heavy depth of shade with C.I. Disperse Blue 284 to evaluate the effect on wetfastness and lightfastness. Finishing with all softeners reduced wetfastness but not lightfastness properties; little correlation was found with softener chemistry. In general, wetfastness and lightfastness of softened poly(lactic acid) fabrics were lower than that of softened poly(ethylene terephthalate) fabrics. The reduction in wetfastness, and particularly crockfastness, of poly(lactic acid) fabric was less marked if the softener was applied by an exhaustion process rather than by a padding process