Leather retanning method

Abstract

The invention relates to a leather retanning method. The method comprises the following steps of: water washing, rewetting to soften, retanning with chrome, neutralization, dyeing to fill, adding grease, dyeing in set and the like; and finally, drying, finishing and coating to obtain the finished product, i.e. leather. In the invention, the process of retanning with chrome is adjusted and a proper environment-friendly tanning agent is adopted, so the content of chrome in chrome liquid can be reduced, the fullness and the toughness of the leather is effectively improved, dyed color is uniform,the heat and humidity resistant stability of the leather can be improved, the physical performances of the leather are uniform, and the finished leather is soft and bend-resistant and is high in tensile strength; the amount of used water in the processing process is small, and the generated industrial waste water is little, so environment protection is facilitated; and the process period is relatively short, so the electric energy consumption is low, the cost is low, and the method has a better economic benefit.

Description

Technical field [0001] The present invention involves the field of tanning, especially a leather tanning method. Background technique [0002] The leather is a degenerative animal skin that has obtained physical and chemical processing through hair removal and tanning.The existing basic technology is: prepare the raw material skin before tanning, then wash, squeeze, and cut it well after chromium tanning, blue wet skin, and then puzzle, alkaline lifting, neutral dyeing, fat add fat, fat add fatIn the end, the color is fixed, and the decoration is made into a finished product leather.The above process has the following defects: 1. During the cutting process, a large amount of chromium -containing waste — chromium leather dandruff has produced approximately 280,000 tons of chromium -containing waste every year.Its landfill, which takes up land resources and environmental pollution; 2. This process produces a large amount of industrial wastewater. These wastewater pHs are 8 to 10, ...

AI Technical Summary

Problems solved by technology

There are following defectives in above-mentioned technology: 1. produce a large amount of chromium-containing waste---chrome leather shavings in the smoothing process, only China just produces about 280,000 tons of chromium-containing waste every year, and the processing mode for chrome leather shavings at present is to Its landfill, this method not only occupies land resources, but also brings environmental pollution; 2. This process produces a large amount of industrial wastewater. content is 60-100mg / l, CODCr is 2000-3000mg / l, S2- (iodometric method) content is 100-200mg / l, BOD5 is 2200mg / l, Cl- 3000mg / l, causing serious pollution to rivers and farmland; 3. The whole process consumes a lot of water, high power consumption, long process cycle and high cost