Deashing-softening-pickling integrated clean tanning method and application thereof

Abstract

The invention provides a deliming-softening-pickling integrated clean tanning method, which is characterized in that deliming, enzyme softening and pickling processes in a conventional tanning process are combined, and salty pickling is replaced by salt-free pickling. The method comprises the following steps: adjusting the pH value of limed bare skin to be acidic by using an ammonium-salt-free dealkalizing agent and non-expansive acid, adding an acidic compound enzyme preparation for softening, and adding the non-expansive acid for salt-free pickling in one bath, so as to achieve the purposes of softening and pickling at the same time. According to the method, conventional pancreatin softening is replaced with acidic compound enzyme softening, ammonium salt, boric acid and neutral salt are completely not added, ammonia nitrogen and chloride ion pollution in the procedures of deliming, softening and pickling can be eliminated from the source, and chromium emission can be reduced; the method can effectively avoid the problem of unstable softening effect caused by poor pH buffering property of the conventional ammonia-free softening bath lotion. The method has wide practicability and is suitable for various leather production processes taking various animal skins as raw materials.

Description

technical field [0001] The invention relates to a tanning technology, in particular to an integrated clean tanning method of deashing-softening-pickling, which belongs to the technical field of leather clean production. Background technique [0002] Enzyme softening is an important process in the tanning process. The delimed bare hide is treated with enzyme preparations to further remove scale, fibrous interstitial and loose structural protein fibers. Because the destruction effect of pancreatic enzyme on the collagen fiber of animal hide is relatively weak, it is relatively safe to use, so it has always been the main enzyme used in leather softening. However, there are also some problems in the use of trypsin. For example, the complex components of trypsin products and large differences between batches make it difficult to control the softening effect stably; The role; the price of pancreatic enzymes is high. Moreover, since the optimum pH value of trypsin is 8-9, ammoniu...

AI Technical Summary

Problems solved by technology

[0007] The object of the present invention is to provide a deliming-softening-pickling integrated clean tanning method in view of the deficiencies in the prior art, so as to realize efficient softening and pickling without using ammonium salt and neutral salt in the tanning preparation section. Tanning with high absorption of chromium to solve the problems of ammonia nitrogen pollution and unstable softening effect in the deliming and softening process of conventional tanning, as well as chloride ion pollution in the conventional pickling process, and can reduce the emission of chromium