A kind of anhydrous chrome tanning process

Abstract

The invention discloses an anhydrous chrome tanning process on the basis of fully considering water saving and reducing chrome discharge. Put the pickled leather into the tanning drum, add plastic balls and cationic oil in turn, start to rotate, then add chrome tanning agent, continue to rotate, then add alkali enhancer, continue to rotate, let stand overnight, and the next day the drum will be obtained. Chrome tanned leather. Using plastic balls instead of water as the medium for chrome tanning can not only ensure moderate mechanical action, but also play the role of a dispersion medium to complete the tanning process, which greatly avoids the generation of waste liquid containing chromium. When the plastic ball is used in the drum, it can increase the extrusion effect of the hide itself, promote the dispersion and penetration of the tanning material in the hide, and ensure the uniform concentration of the tanning material in the hide and between the hides; at the same time, the ball replaces As a solid lubricant, water is adsorbed on the surface of the hide, reducing the friction between the hide and the hide and between the hide and the drum, so as to ensure the safety of tanning; the sphere can also be used repeatedly, which has remarkable practicability.

Description

technical field [0001] The invention relates to the technical field of tanning chemistry and engineering, in particular to an anhydrous chrome tanning process and chrome tanned leather prepared by the process. Background technique [0002] In the tanning industry, chrome tanned leather has the advantages of high strength, softness and fullness, and has occupied a dominant position in the tanning field since its application. However, there are some problems that cannot be ignored in chrome tanning technology: (1) The utilization rate of chrome tanning agent is low: the utilization rate of chromium in the tanning process is only about 80%, and the unused chromium will cause certain pollution to the environment. According to statistics, my country's leather industry produces more than 10 million tons of chromium-containing waste liquid and more than 400,000 tons of chromium trioxide-containing chromium waste residue every year. At present, most of the chromium sludge has not be...

AI Technical Summary

Problems solved by technology

However, there are some problems that cannot be ignored in chrome tanning technology: (1) The utilization rate of chrome tanning agent is low: the utilization rate of chromium in the tanning process is only about 80%, and the unused chromium will cause certain pollution to the environment

According to statistics, my country's leather industry produces more than 10 million tons of chromium-containing waste liquid and more than 400,000 tons of chromium trioxide-containing chromium waste residue every year. At present, most of the chromium sludge has not been effectively treated, which poses a serious hazard to the environment.

(2) Large water consumption: Although tanning enterprises currently use methods such as overloaded drums, small liquid ratio processes, and high-absorption chemical materials to reduce process water consumption and reduce sewage discharge, the water consumption for leather manufacturing is still high

(3) Difficulty in wastewater treatment: The "Tannery and Fur Processing Industry Water Pollutant Discharge Standard" issued in 2014 stipulates that the total chromium content in the wastewater outlets of the existing tannery workshops or production facilities shall not exceed 1.5 mg / L

[0007] Although the above-mentioned chrome tanning processes have their own characteristics, there are still the following deficiencies: First, non-pickling chrome tanning requires strict process control, especially for thicker bare hides, there may be a risk of incomplete tanning, which affects the finished product. leather quality

Secondly, aldehydic small-molecule additives can improve the absorption of chromium, but the chromium content in waste liquid is still high, while polymer additives will cause uneven distribution of chromium and affect the softness of finished leather sensory properties

Finally, the above process is prone to produce waste chrome tanning liquid, which needs to be treated separately

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