The coloration of poly(lactic acid) fibres with indigoid dyes: Part 2: Wash fastness

The fastness of 5% omf dyeings of three indigoid vat dyes on PIA fabric to repeated washing at 40 degrees C, 50 degrees C, and 60 degrees C increased with increasing temperature of their application (60 degrees C, 80 degrees C, 98 degrees C and 110 degrees C). Fastness to repeated washing at 40 degrees C and 50 degrees C was better than at 60 degrees C. Of the three dyes used, C.I. Vat Blue 35 displayed lowest fastness to repeated washing and also lowest colour strength. Comparison of the fastness results on PEA fabric with those of dyeings of three disperse dyes on PIA fabric as well as dyeings of three other vat dyes on PA supermicrofibre revealed both similarities and differences in terms of colour loss and staining of adjacent materials, which highlighted the likely importance of subjecting vat dyeings on PIA fabric to a clearing process in order to remove surplus dye. (C) 2013 Elsevier Ltd. All rights reserved.