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Sodium sulfide-free, lime-free depilation caustic dip method for lining leather of high-grade pig leather shoes

A soda sulfide, lime-free technology, applied in small raw hide/big raw hide/leather/fur treatment, small raw hide/big raw hide/leather skin/fur chemical treatment, tanning treatment, etc., can solve the problem of increasing wastewater treatment costs and cost Great impact on leather quality, environmental pollution and other issues, to achieve the effect of saving water consumption, saving resources and reducing pollution

Inactive Publication Date: 2009-08-19
湖南省怀其皮革集团制革有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The degree of implementation of the above dehairing and liming methods has a great influence on the quality of the finished leather
More importantly, the traditional depilation and liming methods cause serious environmental pollution
The depilation method using alkali sulfide to hydrolyze and dissolve pig hair, resulting in COD value and NH in wastewater 3 -N value is high, not only wasting resources, but also increasing the cost of wastewater treatment
In the liming process, a large amount of lime is used to produce a buffer effect, and then waste residue is formed in the later stage, causing pollution to the environment
It is not only a waste of resources, but also difficult to deal with, and has become one of the "difficulties" in the tanning industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] (1) Soaking

[0041] After weighing the raw hides, wash them with water at 18-22°C for 30 minutes and drain. Take 100 kilograms of washed raw hides and put them into the drum. Add 100-150 kilograms of water at 24℃, 2 kilograms of sodium carbonate, and 0.1 kilograms of caustic soda. Rotate for 40 minutes to adjust the pH of the solution to 9.0. Add 0.6 kg of anionic degreasing agent and 0.1 kg of water soaking agent, rotate for 150 minutes, stop the drum and soak for 10 hours, and drain;

[0042] (2) Rolling salt

[0043] Take 100 kilograms of raw hides after soaking in water, put them into the drum, add 3 kilograms of salt, 0.2 kilograms of preservatives, rotate for 20 minutes, and take out the drum;

[0044] (3) Enzymatic hair removal

[0045] Take 100 kg of raw hides after rolling salt, mix 0.2 kg of mixed enzyme, 0.3 kg of neutral protease, 0.2 kg of soda ash, 5 kg of fine rice bran, and 10 kg of water, and mix thoroughly. Brush the buttocks of the raw hide with a bristl...

Embodiment 2

[0055] (1) Soaking

[0056] After weighing the raw hides, wash them with water at 18-22°C for 60 minutes and drain. Take 100 kilograms of raw hides after washing, put it into the drum, add 150 kilograms of water at 26℃, 3 kilograms of sodium carbonate, 0.2 kilograms of flake caustic soda into the drum, rotate for 60 minutes, adjust the pH of the solution to 9.5, and then add anions 0.8 kg of degreasing agent and 0.2 kg of water soaking agent, rotate for 180 minutes, stop the drum and soak for 12 hours, and drain;

[0057] (2) Rolling salt

[0058] Take 100 kg of raw hides after soaking in water, put them into the drum, add 5 kg of salt, 0.4 kg of preservatives, rotate for 30 minutes, and take out the drum;

[0059] (3) Enzymatic hair removal

[0060] Take 100 kg of raw hides after rolling salt, mix 0.4 kg of mixed enzyme, 0.5 kg of neutral protease, 0.3 kg of soda ash, 7 kg of fine rice bran, and 15 kg of water, and mix thoroughly. Brush the buttocks of the raw hide with a bristle b...

Embodiment 3

[0070] (1) Soaking

[0071] After weighing the raw hides, wash them with water at 18-22°C for 45 minutes and drain. Take 100 kilograms of raw hides after washing and put them into a drum. Add 125 kilograms of water at a temperature of 24 to 26 ℃, 2.5 kilograms of sodium carbonate, and 0.15 kilograms of caustic soda. Rotate for 50 minutes to adjust the pH of the solution to 9.2. Add 0.7 kg of anionic degreasing agent and 0.15 kg of water soaking agent, rotate for 165 minutes, stop the drum and soak for 11 hours, and drain;

[0072] (2) Rolling salt

[0073] Take 100 kilograms of raw hides after soaking in water, put them into the drum, add 4 kilograms of salt, 0.3 kilograms of preservatives, rotate for 25 minutes, and take out the drum;

[0074] (3) Enzymatic hair removal

[0075] Take 100 kg of raw hides after rolling salt, mix 0.3 kg of mixed enzyme, 0.4 kg of neutral protease, 0.25 kg of soda ash, 6 kg of fine rice bran, and 12.5 kg of water, and mix thoroughly. Brush the buttoc...

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PUM

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Abstract

The invention relates to a depilation caustic dipping method of the lining leather of high quality pigskin shoes without using sodium sulfide and lime, which is characterized in that the method can greatly reduce the pollution of S and waste residue in waste water caused by sodium sulfide, sodium sulfhydrate and the lime in the process of traditional leather manufacturing process, and the discharge amount of the waste water is reduced by 40% and is easy to treat compared with the conventional depilation liming working procedure. Meanwhile, a non-ammonia dealkalization method is adopted to greatly reduce the content of NH3-N in the waste water. Compared with the traditional technique, the method can shorten the production period, save materials and reduce the comprehensive cost of production.

Description

Technical field [0001] The invention relates to an alkali-sulfide-free and lime-free alkali-soaking method for high-grade pigskin shoe lining leather, and belongs to the production field of leather tanning. This method is suitable for the dehairing and soaking alkali treatment of pigskin shoe lining leather before tanning, which is currently required on the market. Background technique [0002] In the production process of pigskin shoe lining leather, hair removal and removal of the epidermis are natural and necessary processes. The traditional process is to use alkali sulfide to break the disulfide bonds in the keratin contained in the pig hair to hydrolyze the pig hair and epidermis. To achieve the purpose of hair removal. But the hair removal method caused the most serious S 2- , COD emissions. [0003] In the tanning process, the liming process has a history of thousands of years, and it has been used to this day. Its importance has been generally recognized by scientific and...

Claims

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Application Information

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IPC IPC(8): C14C3/04
Inventor 周新良单志华朱强罗建勋
Owner 湖南省怀其皮革集团制革有限公司
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