Pickling of hides and skins

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General description

Pickling is carried out to reduce the pH of the pelt prior to mineral tanning and some organic tannages (e.g. chrome tanning, glutaraldehyde tanning, and vegetable tanning), thereby sterilising the skin, ending the bating action, and improving the penetration of the subsequent tanning material.

The choice of the exact pickling parameters depends on the subsequent tanning step. Pickling involves treating the bated stock with a solution of sulphuric acid and common salt. The process not only serves to prepare the stock for subsequent tanning, but also if necessary in the preservation of the stock for quite long periods. The pH of the medium is kept at around 3.5. Tanning can be carried out in the pickle liquor, where both operations are undertaken at the same location.

Typical process parameters

Process Temperature [°C] Heat transfer medium Residence time Details Literature
Pickling 30-37 °C water and chemicals continious swelling reduction BASF. (2007). Pocket book for the leather technologist (4. Auflage).

Source: Joint Research Centre, Best Available Techniques (BAT) Reference Document for the Tanning of Hides and Skins, 2013

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