Difference between revisions of "Neutralising"
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| − | + | Acids which have penetrated into the leather during [[tanning leather|tanning]] are removed 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]]. There are no attempts to bring the [[pH value]] of leather to 7 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. | |
== [[Leather videos|Video]] about the [[leather production]]== | == [[Leather videos|Video]] about the [[leather production]]== | ||
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| − | <flashow> | + | <flashow>//www.youtube.com/v/-qn5R8dKcss&fs=1&color1=0x660000&color2=0x550000&border=1|width=500|height=281,25</flashow><br></p> |
<p align=center> | <p align=center> | ||
''The [[leather production]] in a modern [[tannery]].'' | ''The [[leather production]] in a modern [[tannery]].'' | ||
</p> | </p> | ||
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! bgcolor=#eeeeee | [[Leather production|Process steps in the leather production]] | ! bgcolor=#eeeeee | [[Leather production|Process steps in the leather production]] | ||
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| − | | bgcolor=#ffffff align=center | [[storage of leather| | + | | bgcolor=#ffffff align=center | [[storage of leather|Storage]] - [[soaking]] - [[Liming - Leather Tanning|liming]] - [[Fleshing - Making of leather|fleshing]] - [[Split leather|splitting]] - [[pickling]] - [[Tanning leather|tanning]] - neutralising - [[Drying leather|withering]] - [[Leather production#Sorting|sorting]] - [[shaving]] - [[Leather production#Dyeing - Fatliquoring - Re-tanning|dyeing - fatliquoring - retanning]] - [[Drying leather|drying]] - [[finish]] - [[softening]] - [[Leather quality|final check]] |
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</center> | </center> | ||
Latest revision as of 16:16, 13 December 2022
Acids which have penetrated into the leather during tanning are removed during the neutralising stage. Alkaline sodium carbonate is used in a concentration of 1.2%. Neutralising is necessary, to allow fat-liquoring. There are no attempts to bring the pH value of leather to 7 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 - fatliquoring - retanning - drying - finish - softening - final check |
| Tanning methods |
|---|
| Chrome tanning - Vegetable-tanned leather - Synthetic tanning - Tanning with fats and oils |
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