Raw leather is made up of three main layers. The middle layer (corium) is the one to react with the tanning agent and to constitute the leather product, while the others are removed during processing. The bottom layer (ipodermis) is mostly removed by mechanical means (fleshing). The upper layer (epidermis) and the hair are removed by chemical means (liming).
Bating results in the removal of all unwanted proteins that remain after the liming phase. In particular, during this phase the unhaired, fleshed and alkaline hides are neutralized with acid ammonium salts and treated with enzymes, similar to those found in the digestive system, to remove hair remnants and to degrade proteins. This phase produces the largest part of the ammonium load of the effluents.
The PODEBA project will demonstrate an innovative, natural and sustainable process, capable of providing the same results as traditional bating techniques, while at the same time cutting the environmental impact of tanneries and reducing water consumption.