A process for tanning and softening sheepskin with polycarboxy-based nano-composite chrome tanning aids

Abstract

The invention belongs to the field of leather tanning process and relates to a process for tanning and softening sheepskin by a multi-carboxylic nano compound chrome tanning additive. In a traditional chrome tanning method, the use of various chemicals in picking and chrome tanning procedures causes damage to the ecological environment. According to leather tanning mechanisms and structural features of collagenous fiber and the multi-carboxylic nano compound chrome tanning additive, the process used for leather tanning and skin softening is characterized in that the shrinkage temperature of blue wet leather can reach 105 DEG C, the grain side is flat and fine, and the requirements of goat skin garment leather can be met; compared with the method that 8 percent of chromium powder is adopted for conventional tanning liquid waste, liquid waste is characterized in that the content of Cr2O3 in the liquid waste is reduced to 172 mg / L from 1,952 mg / L, and the content of chromium in the liquid waste is reduced greatly; compared with the conventional chrome tanned leather, the chrome tanned leather treated through the process has the advantages that excellent effects to follow-up backwater, neutralization, and control to chromium pollution in dying and oiling liquid waste are achieved, the physical and mechanical performance of crust leather is similar, compact hand feeling is achieved, the filling performance and the softness are excellent, and the requirements of the goat skin garment leather can be met.

Description

technical field [0001] The invention belongs to the field of leather tanning technology, and in particular relates to a technology for tanning and softening sheepskin with polycarboxy-based nano-composite chrome tanning auxiliaries. Background technique [0002] In recent years, with the strengthening of international environmental protection, traditional tanning enterprises are facing unprecedented challenges. The traditional chrome tanning method uses a variety of chemicals to treat leather for a long time through different unit operations, which makes the COD value and Cl in the chrome tanning wastewater - , sulphate and other mineral salts increased. And in the traditional traditional chrome tanning process, most leather factories use 6%~8% chrome powder to ensure the quality of finished leather, but the traditional chrome tanning process, the absorption rate of chrome is only 65%~75%. %, Cr in waste liquid 2 o 3 As high as 1500~3000mg / L, if it is not absorbed, it wi...

AI Technical Summary

Problems solved by technology

In recent years, the preparation of organic-inorganic composite materials by compounding organic polymers and inorganic nanomaterials has become one of the research hotspots of Chinese and foreign experts because of their good synergistic effect; chrome-free tanning agents or chrome tanning auxiliaries with certain environmental significance have been developed. However, there are few reports on the process of applying polycarboxy-based nano-composite chrome tanning auxiliaries to the leather tanning process to tan goat nude leather.