The Cr.AB process: A new ecological process for the transformation of pickled hides into leather: Part 2: Dyeing

Floats containing chemical constituents which are to a varying extent harmf ul to the environment are produced from every stage of the aqueous phase in leather and hide processing. There are purification processes which reduce the noxious effect but these create a quantity of sludge which is, nowaday s increasingly difficult to use or dispose of. Consequently, it seems usefu l to seek solutions in which floats are free from chromium, fats and dyestu ffs, to allow recycling during manufacture. In a previous paper, we described a new leather chrome-tanning process, the Cr.A.B. tanning process, using seIf-basifying and masking agents, which gi ves the high exhaustion of chrome-tanning liquors. In this work, research h as been done to study dyeing in the Cr.A.B. process. We took into account d ye exhaustion; chromium released; factors that influence dyeing behavior an d the quality of the dyed leathers.