Abstract

Our research is in the area of minimisation of industrial waste in the leather industry. This contribution is concerned with the processing of chromed collagen residues produced at each of the different stages of production. These are:

group I: chromed residuals – tanning and drying stage – crust state
group II: chromed residuals + fatty matter – fatliquoring stage
group III: chromed residuals + fatty matter + retanning agents – retanning stage
group IV: chromed residuals + fatty matter + retanning agents + dyestuff – dyeing stage
group V: chromed residuals + fatty matter + retanning agents + dyestuff + acrylic and /or polyurethanes – finish stage

Group V residues represent the highest percentage of the total volume of residues and they are also the most complex. The group includes the trimmings from industrial manufacturers of leather products such as footwear, clothing and upholstery. Chromed collagen residues are those stabilised or crosslinked with chromium (III) salts which block any later treatment to obtain gelatine using conventional methods. A large part of this type of residue is used for the production of agglomerates known as regenerated leather, mixing with latex in dutch-piles, from which various articles are manufactured.