Production technology of cow skin nappa leather

Abstract

The invention relates to the technical field of the leather manufacturing technology, and provides a production technology of cow skin nappa leather. A series of problems that due to the fact that the structure of the abdomen and the part between the ribs and the hips of the cow skin is thin and fiber is woven loosely, in the processing process, the part of the abdomen and the part between the ribs and the hips are prone to being excessively loose, the part deviation is large, and face loosening is likely to happen are solved through the production process of the cow nappa soft-face leather. The integral procedure of the technology is simple, easy to achieve, convenient to operate and practical. The grain on the abdomen and the part between the ribs and the hips is easy to open in the tan preprocessing working section of the cow skin through tanning preprocessing, retanning processing and post-tanning mechanical processing, and the whole skin body fiber is even and loose. Even and slow tanning is carried out in the tanning working section, step-by-step and multi-time even filling is carried out in the retanning working section, the whole cow skin leather is even and consistent in the manner that filling is conducted after loosening, the leather is soft but not loose, and the leather yield and the utilization rate of finished cow skin are greatly increased.

Description

technical field [0001] The invention relates to the technical field of leather production technology, in particular to a production technology of cowhide nappa leather. Background technique [0002] At present, the leather market is mainly dominated by three major raw materials (pigskin, cowhide, and sheepskin), among which domestic yellow cowhide and European and American raw material leather are mostly used for cowhide. The production requirement of cowhide nappa soft surface leather is to be quite soft and without hard core. The requirements for the core of the leather are the same as those for the grained meat surface. Most of the interstitial fibers must be removed and the collagen fibers must be fully loose. In the traditional leather processing method, first of all, when the leather core has not yet reached the requirements, the grain surface and the flesh surface have been softened enough. elongation and other phenomena; secondly, cowhide nappa soft top leather requ...

AI Technical Summary

Problems solved by technology

In the traditional leather processing method, first of all, when the leather core has not yet reached the requirements, the grain surface and the flesh surface have been softened enough. elongation and other phenomena; secondly, cowhide nappa soft top leather requires the softness and hardness of the whole leather to be basically uniform, for example, the buttocks should not be too hard, and the side belly should not be too soft, but this requirement is extremely difficult to control in actual operation; finally, for nappa As far as soft leather is concerned, the wrinkles on the grain surface of cowhide must be stretched out, and the key to opening wrinkles is to destroy or loosen the fiber structure that forms wrinkles, but it is difficult to grasp how to loosen moderately without excessive treatment.

[0003] In related technologies, the common cowhide nappa soft leather processing methods are mostly aimed at domestic yellow cowhide, American heavyweight leather, European leather, Yan cowhide, and calfskin. The side belly structure is thin, the fiber weave is loose, and there are few fibers at the junction of the grain layer and the reticular layer, and the difference is very large, so it is easy to cause the side belly part to be too loose during processing, and the position difference is too large, resulting in loose noodles. Dairy cowhide has a lot of lines and heavy texture on the abdomen, which affects a series of problems such as the yield and utilization of the finished product

Due to the large differences in the fiber structure of dairy cowhide, the processing methods in the traditional related technologies are no longer suitable for the production of cowhide (including retanning, tanning, and processes such as soaking and deliming before tanning)