What is shrinkage temperature

Shrinkage temperature

The temperature at which the collagen and substance begin to shrink with the influence of water is called shrinkage temperature.

Shrinkage temperature is an indicator of strength and number of cross linkage present inside the leather. Since the shrinkage temperature of finished leather goes down with time, it can give rough idea about the age of leather.
For example, the shrinkage temperature or hydrothermal stability of chrome tanning is approx. 100°C, raw hides/ skins is 60°C, liming hides/ skins is 40°C, aldehyde tanned leather is 90°C.

Shrinkage temperature of chrome tanned leather is higher than the vegetable tanned leather

Shrinkage temperature is an indicator of strength and number of cross linkages present inside the leather. After tanning and drying when the leathers are stored their shrinkage temperature slowly goes down. Thus the cross linking power of chrome tanning compound present inside the tanned leather goes down reducing the shrinkage temperature slowly and of the number of cross link between collagen and tanning materials is increased, the shrinkage temperature is also increase. Naturally, the shrinkage temperature value of chrome tanned leather is 100 - 120°C and the vegetable tanned leather is around 80°C. Since the chrome tanned leather has produced the highest number of cross linkages than vegetable tanned leather. So that, the shrinkage temperature of chrome tanned leather is higher than vegetable tanned lather.