Tanning After-Treatment Processes

Tanning After-Treatment Processes

There are some treatments that are given to leather after they have been tanned. Some of these include washing, setting out, oiling, stuffing, and drying.

It is also referred to as scouring. This is done to remove any surplus tan from heavy leathers and chrome salts from light leathers.

Setting Out
This is done to stretch the leather to remove any wrinkles and flatten heavy leather. It is also done to remove creases and surplus moisture in light leather. After this process, the pelts still contain about 60% moisture.

This is the application of oil to the grain side of the leather for it to be flexible and be of good colour. It is done to replace the oil lost during earlier treatments.

This is the process of impregnating the leather with oil and fat to make it waterproof or suitable for mechanical leathers or make it more resistant to wear.

This is done by pasting the hide onto a glass plate or metal sheet or by toggling that is pinning the leather onto a large wooden sheet with holes in it. This is done to compress the leather and make it firm and flat. Another process of drying it is to paste the pelts on large plates. It is then scrubbed, wiped and dried either with the solar energy or in a drying oven. The drying process also helps to remove the remaining moisture or water and smooths the grain. Again, it helps in avoiding hardening or shrinkage of the leather.

This is the process of re-wetting the pelt with a fine spray mist of water to raise the moisture content to about 25%. The drying process makes the pelt too hard and unworkable for most consumer use. Therefore, this is done to re-establish the pelt to its proper moisture content.

This is the process of mechanically softening the pelt by both pulling and rolling to make it pliable. It gives the leather its final firmness and softness.

This is a mechanical sanding process that reduces the visual appearance of surface blemishes on the grain side of the leather. A full grain leather is not buffed.

This is the process of applying a thin finish film on the grain side of the leather to enhance the colour and increase the pelt’s resistance to stain and abrasion.

This process smoothes the finish grain surface and assists in fixing the finishing film on the leather.