Combined organic tanning based on mimosa and oxazolidine: Development of a semi-industrial scale process for high-quality bovine upper leather

In this study we present an industrial-scaled tanning process intended to replace chrome tanning in the production of high quality bovine shoe upper leathers using a combined tannage based on a mimosa and oxazolidine as cross-linking agent. This paper reports the best recipe developed and the properties of the leather obtained. The various test results and scanning electron microscopy (SEM) observations which were used as investigative methods to follow the tanning process steps and to better understand the cross-linking mechanisms, are detailed together with the characterisation of the effluents. The leather obtained is characterised by a good hydrothermal stability coupled with good physical and technical properties which allow it to easily comply with the standards required for high quality chromium-tanned bovine upper leather. The results obtained suggest that this tannage is a promising alternative to traditional chrome tanning.