Articles - Leather Technology Magazine Nº77

Influence of auxiliary products in mimosa tanning

Influence of auxiliary products in mimosa tanning

Work presented at the 3rd National Technical Symposium of the Tanning Industry, Buenos Aires, November 2010

Eng. Mariana I. Lorenzo (1)
Eng. Juan Carlos Karachov (2)
Dr. Ramón Palop (2)
Dr. Pablo E. A. Rodríguez (1)

(1) CEPROCOR (Center for Excellence in Products and Processes of Córdoba),
Córdoba’s Ministry of Science and Technology
Santa María de Punilla (5164) Córdoba, Argentine Republic

(2) Tanning Laboratory, Units Sudamericana S.A.
Sta. M. Del Buen Ayre 362/4, Buenos Aires, Argentine Republic

ABSTRACT

Tanning and re-tanning with vegetal products, especially, mimosa, are processes used widely to manufacture any type of articles.
This study assesses the influence of three types of products in the physical and organoleptic characteristics of leather tanned and/or retanned with mimosa and different amounts of these auxiliary products.
The first part involves tanning on pickel leather and at a small scale (pieces), assessing the tanning capacity at different concentrations by assessing the contraction temperature and shrinkage, the speed of penetration of the tanning agent, the fastness to light and temperature, the tanning color, as well as the organoleptic properties (degree of softness, thickness and firmness)
The second part involves the application of on pre-tanned leather and at higher scales (flanks) with a specific formulation for leather goods, where only the use of mimosa is compared with variables where the abovementioned auxiliary products are added.
Product N° 1 (salt of naphthalene sulfonic acid) increases the mimosa speed of penetration, resulting in a better stratigraphical distribution. The leather is very soft, with loose grain, suitable for drummed articles.
Product N° 2 (phenol polymer) does not provide any properties that may improve tanning with mimosa only. Moreover, they are tough, loose grain leathers.
Product N° 3 (salt of diphenyl sulphona) increases contraction temperature, significantly improving the speed of penetration. It results in firm and soft leathers, with very clean and neat colors and regular and uniform thickness.