How to choose retanning agent for cattle waxing leather according to product requirements?

The properties and styles of various products are largely determined by retanning. Therefore, what products are processed is the main basis for selecting retanning agents.  What principles should be followed in the selection of retanning agent for cattle waxing leather?  

1, cattle waxing leather performance requirements.  

The grain surface is meticulous, the color is uniform, the extensibility is small, can produces the fashionable effect of color changes and deep discoloration after polishing.  

2. Selection of retanning agent.  

(1) The effect of waxing leather mainly comes from two aspects: first, the color of tannin extract contained in the leather changes after high temperature polishing, which makes the leather surface darker, natural gloss and strong transparence;  The other is to migrate the unstable oil and produce "oil discoloration" effect through high temperature friction in finishing.  Therefore, in the wet processing of waxed leather after tanning, in addition to the reasonable combination of fatliquoring agents, the retanning agent should be mainly retanned by vegetable tannin extract, which is generally about 15% of the weight of wet blue leather.  

(2) In retanning with large doses of tannin extracts, it is required that tannin extracts have good penetration and uniform filling in order to obtain fine and firm grain surface, even and full color, and full hand feel without rigidity. To achieve this, in addition to control neutralizing pH value close to the isoelectric point of the skin (4.8-5.0) as far as possible,  Another good option is to use a certain amount of syntan agent which disperses tannin extracts, and the thicker the skin, the greater the proportion of syntan agent used.