Investigation into the eco-friendly, simultaneous tanning and reactive dyeing of leather

The leather industry is facing increasing environmental pressure, with ongoing scrutiny of its chemical usage, processing conditions, end-of-life criteria and CO2e footprint. This paper presents a disruptive technology that delivers a groundbreaking approach to addressing these immediate challenges for the leather industry. The patented Avicuero system provides a "green" technology enabling simultaneous tanning and dyeing, which is completely free of metals, aldehydes and bisphenols, with the resultant leather offering good hydrothermal stability combined with excellent depth of shade and colour fastness properties. Analyses of the dyeing process demonstrated excellent penetration of the leather substrate and near complete exhaustion and fixation of the reactive colourants (based on halotriazine and sulphatoethyl sulphone chemistry), leading to excellent colour strength for the Avicuero Black SL tanned leather, with superior fastness performance relative to competitive tanning technologies. In addition, the multifunctional reactive dye/collagen crosslinking imparted effective tanning to the leather with a hydrothermal shrinkage temperature of 77 degrees C. Further technical advantages are the significant reductions in water and energy requirements (reduced machine processing time and processing temperatures) compared with current industrial technologies, and continuing to use current standard tannery processing equipment.