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A method for preparing protein filler for tanning by recovering cow hair from tanning hair preservation and depilation

A technology for hair preservation and depilation and protein, which is applied in the field of preparing protein fillers for tanning, which can solve the problems of multiple solid waste, affecting the color and appearance of leather, and restricting the application of tanning, so as to achieve resource recycling and excellent retanning Filling effect, effect of fine application effect

Active Publication Date: 2019-06-25
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The problem with this method is that the resulting protein filler is dark in color, which seriously affects the color and appearance of leather after being used in the retanning filling process, which greatly limits its application in tanning.
The literature (Pu Jianmin, Mao Pei, Shen Xiaojun, et al. Research on hydrolysis process of hair alkali recovery from hair preservation and depilation. Leather Science and Engineering, 2014, 24(3): 52-58.) reported a method of first using NaHSO 3 The cow hair hydrolysis method of pretreatment and subsequent NaOH hydrolysis has the problem that during the cooling and filtration process, the soft and easily deformable solid impurities in the viscous hydrolyzate will form a dense filter cake with a structure that is easy to be compressed, and the suspended Particles will block the filter channel, making it difficult to filter, while the pigment remains in the hydrolyzate, so that the color of the hydrolyzate is still dark
In addition, although the cow hair in the above-mentioned methods has undergone two-step reactions of pretreatment and alkali hydrolysis, the hydrolysis rate is below 90%. Even if it can be separated after alkali hydrolysis, a lot of solid waste will still be generated.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Put 100 parts of cow hair recovered from tanning, depilation, and depilation into a reactor, add 16 parts of NaOH, 4 parts of MgO, 1.5 parts of sodium aluminosilicate, and 800 parts of water, react at a temperature of 90°C for 10 hours, filter and collect filtrate;

[0022] (2) Put the filter residue of step (1) in a reactor, add 2 parts of KOH and 100 parts of water, react at a pressure of 0.2 MPa and a temperature of 130°C for 5 hours, filter and collect the filtrate;

[0023] (3) Roasting the filter residue of step (2) at a temperature of 500°C for 4 hours, and the obtained powder is reused in step (1) to replace MgO and sodium aluminosilicate;

[0024] (4) Mix the filtrates collected in steps (1) and (2), adjust the pH to 6 with hydrochloric acid to obtain a liquid protein filler for tanning, or dry the liquid protein filler for tanning to obtain a solid protein filler for tanning.

[0025] In this step, the chromaticity and color difference values ​​of the mix...

Embodiment 2

[0047] (1) Put 100 parts of cow hair recovered from tanning, depilation, and depilation into a reactor, add 6 parts of KOH, 8 parts of CaO, 1 part of sodium aluminosilicate, and 1000 parts of water, react at a temperature of 70 ° C for 8 hours, filter and collect filtrate;

[0048] (2) Put the filter residue of step (1) in the reactor, add 0.5 parts of NaOH, 0.5 parts of Ca(OH) 2 , 0.5 parts of KOH, 50 parts of water, react at a pressure of 0.8 MPa and a temperature of 190°C for 2 hours, filter and collect the filtrate;

[0049] (3) Roast the filter residue of step (2) at a temperature of 800°C for 1 hour, and use the obtained powder back in step (1) to replace CaO and sodium aluminosilicate;

[0050] (4) Mix the filtrates collected in steps (1) and (2), adjust the pH to 7.5 with sulfuric acid to obtain a liquid protein filler for tanning, or dry to obtain a solid protein filler for tanning.

Embodiment 3

[0052] (1) Put 100 parts of cow hair recovered from tanning, hair preservation and depilation into the reactor, and add 20 parts of Ca(OH) 2 , 2 parts CaO, 2 parts Al 2 o 3 , 2 parts of MgO, 1 part of sodium aluminosilicate, 700 parts of water, react at a temperature of 87 ° C for 6 hours, filter and collect the filtrate;

[0053] (2) Put the filter residue of step (1) in the reactor, add 0.5 parts of NaOH and 80 parts of water, react at a pressure of 0.6 MPa and a temperature of 170°C for 3 hours, filter and collect the filtrate;

[0054] (3) Roast the filter residue of step (2) at a temperature of 700°C for 3 hours, and the obtained powder is used in step (1) instead of CaO and Al 2 o 3 , MgO and sodium aluminosilicate;

[0055] (4) Mix the filtrate collected in steps (1) and (2), adjust the pH to 6 with nitric acid to obtain a liquid protein filler for tanning, or dry to obtain a solid protein filler for tanning.

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PUM

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Abstract

The invention discloses a method for using cowhair recycled by hair saving and unhairing in leather process to prepare protein filling used in leather. The method is characterized by comprising the steps of using the cowhair recycled by hair saving and unhairing in leather process as a raw material, adopting an alkaline process to conduct synthetic hydrolysis on cowhair, and filtering and collecting filtrate liquor; using little amount of strong base to conduct hydrolysis again on filter residue at a high temperature and high pressure, and filtering and collecting filtrate liquor; mixing the filtrate liquor collected in the two steps above, and using inorganic acid to adjust pH to obtain a liquid protein filling, or drying the mixed liquor to obtain a solid protein filling; conducting high-temperature roasting on the filter residue to obtain powder which is reused in alkaline hydrolysis of the cowhair. According to the method for using cowhair recycled by hair saving and unhairing in leather process to prepare protein filling used in leather, rapid filtration after hydrolysis of the cowhair is achieved, the obtained liquid or solid protein filling is light in color, the hydrolysis rate of the cowhair is high, and no solid waste is generated. Therefore, the method for industrialized production of the protein filling is easy to operate, and economical and practical.

Description

technical field [0001] The invention belongs to a method for preparing a protein hydrolyzate, in particular to a method for preparing a protein filler for tanning by using recovered cow hair as raw material. Background technique [0002] In order to reduce the pollution caused by the depilation and depilation method to waste water, tannery enterprises are vigorously promoting the application of the hair preservation and depilation method that allows the cow hair to come off relatively completely. The resulting recycled cow hair is huge and rich in keratin, which can be recycled as a resource after recycling. In the tanning industry, the recovered cow hair can be hydrolyzed into protein hydrolyzate with suitable molecular weight distribution to prepare protein fillers, which can be used in the retanning and filling process of tanning to obtain leather with excellent hand feeling and hygienic performance. This is not only an effective way to resourcefully utilize cattle hair,...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07K1/12C07K1/34C14C3/08
CPCC07K1/12C07K1/34C14C3/08
Inventor 王亚楠石碧张文昌周建飞廖学品余跃
Owner SICHUAN UNIV