Difference between revisions of "Neutralising"
From www.leather-dictionary.com - The Leather Dictionary
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| − | + | Acids which have penetrated into the leather during [[tanning leather|tanning]], is removed again during the Neutralising stage. Alkaline sodium carbonate is used in a concentration of 1.2%. Neutralising is necessary, to allow [[Oils & fats in the leather industry|fat-liquoring]]. No attempts to bring the [[pH value]] of leather to 7 are made during this stage, since this would dissolve the binding of the [[tannins]] to the skin-fibres and thus drastically reduce the [[leather quality|durability]] of the leather. In practice, a pH value of 4-6 is desired. | |
Revision as of 10:17, 12 February 2017
Acids which have penetrated into the leather during tanning, is removed again during the Neutralising stage. Alkaline sodium carbonate is used in a concentration of 1.2%. Neutralising is necessary, to allow fat-liquoring. No attempts to bring the pH value of leather to 7 are made during this stage, since this would dissolve the binding of the tannins to the skin-fibres and thus drastically reduce the durability of the leather. In practice, a pH value of 4-6 is desired.
Video about the leather production
The leather production in a modern tannery.
| Process steps in the leather production |
|---|
| storage - soaking - liming - fleshing - splitting - pickling - tanning - neutralising - withering - sorting - shaving - dyeing (through colouring) and fatliquoring - drying - finish - softening - final check |
| Tanning methods |
|---|
| Chrome tanning - Vegetable-tanned leather - Synthetic tanning - Tanning with fats and oils |
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