A kind of leather retanning and dyeing process

Abstract

The invention relates to the field of leather processing and provides a leather retanning and dyeing process through which the dyeing accuracy and color fullness can be obviously improved, the manual labor is effectively saved, the energy consumption and material cost are reduced, the environmental pollution is reduced and the dyeing wastewater treatment difficulty is reduced. The leather retanning and dyeing process sequentially comprises the process steps: bleaching, retanning, neutralizing, filling, stuffing and dyeing, wherein the pH in the dyeing process is controlled to be 3.5-4.5, and the dye amount is 1.5-2.5 percent.

Description

technical field [0001] The invention relates to the field of leather processing, in particular to a leather retanning and dyeing process. Background technique [0002] The traditional leather retanning and dyeing process is: rinsing→retanning→neutralization→filling, dyeing→fatliquoring→chromatography. The dyeing process is carried out in the middle of the retanning and dyeing process. In this way, the dye-containing waste liquid must be discharged from the middle of the dyeing process, and even some processes need to add dyes for pre-dyeing during rinsing. The wastewater discharged from this process contains dyes from the beginning to the end, which increases the difficulty of treatment. The leather retanning and dyeing process requires more than 20 tons of water, and at least discharges more than 12 tons of wastewater containing dyes, which brings serious environmental problems. At the same time, the traditional leather retanning and dyeing process steps are relatively com...

AI Technical Summary

Problems solved by technology

[0002] The traditional leather retanning and dyeing process is: rinsing→retanning→neutralization→filling, dyeing→fatliquoring→chromatography. The dyeing process is carried out in the middle of the retanning and dyeing process. In this way, the dye-containing waste liquid must be discharged from the middle of the dyeing process, and even some processes need to add dyes for pre-dyeing during rinsing. The wastewater discharged from this process contains dyes from the beginning to the end, which increases the difficulty of treatment. The leather retanning and dyeing process requires more than 20 tons of water, and at least discharges more than 12 tons of wastewater containing dyes, which has brought serious environmental problems

At the same time, the traditional leather retanning and dyeing process steps are relatively complicated. Dyeing is often carried out in the same bath with multiple processes such as filling, fatliquoring, retanning and even neutralization. There is no obvious distinction between the processes. There is a competitive relationship in the combination of leather, which affects the dyeing effect, and requires more chemicals and manpower

[0003] Therefore, the above-mentioned traditional leather retanning and dyeing process is used to process leather, and a large amount of dye-containing sewage produced is difficult to treat and pollutes the environment. The effect of leather dyeing is poor, the accuracy is low, and the color fullness is poor.