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Chrome-free tanning process for ecological leather

A chrome-free tanning and ecological technology, applied in the field of leather processing, can solve the problems of the limitation of the promotion and application of chrome-free tanning technology, increasing the organic pollution load of dyeing and finishing wastewater, and the insufficient bonding rate of dyeing and finishing materials, and achieves improved distribution uniformity and positive electricity. The effect of strong sex and high isoelectric point

Active Publication Date: 2022-04-29
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The suppleness of the crust leather obtained by this method is good, but there is a problem that the TWS tanning agent mainly reacts with the amino group of skin collagen, so that the isoelectric point of tanned wet white leather does not exceed 5.0, resulting in subsequent dyeing and finishing materials (currently generally anionic type materials) the binding rate is not high enough, which not only causes waste of dyeing and finishing materials, but also increases the organic pollution load in dyeing and finishing wastewater
In this method, the TWLZ tanning agent is positively charged, and mainly undergoes a coordination reaction with the carboxyl group of skin collagen, so that the isoelectric point of wet white leather reaches above 7.0, and has good absorption and binding ability to anionic dyeing and finishing materials, but the existing The problem is that the softness of the crust leather obtained after dyeing and finishing of wet white leather is low, and it is difficult to meet the "soft and foamy" requirements of today's leather products.
Due to the above problems, the promotion and application of TWS and TWLZ chrome-free tanning technologies are limited to a certain extent

Method used

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  • Chrome-free tanning process for ecological leather

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Put the pickled cowhide obtained according to the conventional process in a drum, add 60 wt% of pickling solution based on the weight of limed bare hide and 5 wt% of chrome-free organic tanning agent TWS, rotate for 3 h, and use sodium carbonate After raising the alkali with sodium bicarbonate to pH 7.7, add 150 wt% hot water based on the weight of liming bare hide, keep the temperature of the bath liquid at 42°C, rotate for 2 hours, stop the drum overnight, and turn for 0.5h the next day Finally, drain the liquid; add 30 wt% normal temperature water and 2.5 wt% sodium lignosulfonate based on the weight of liming bare hide into the drum, rotate for 1.2 h, adjust the pH of the bath solution to 3.8 with formic acid, and then add chrome-free metal tanning agent TWLZ with 4 wt% by weight of liming bare hide, continue to rotate for 4 h, use automatic alkali raising agent MGO to elevate alkali to pH 4.0, add 200 wt% hot water by weight of liming bare hide, Keep the temperatur...

Embodiment 2

[0072] Put the pickled goatskin obtained by the conventional process in a drum, add 100 wt% of pickling solution based on the weight of limed bare hide and 3 wt% of chrome-free organic tanning agent TWS, rotate for 4 h, and use carbonic acid Sodium and sodium bicarbonate to improve the alkali to pH 8.5, add 200 wt% hot water based on the weight of liming bare hide, keep the temperature of the bath at 35°C, rotate for 1 hour, stop the drum overnight, and turn 0.5% the next day After 2 hours, drain the liquid; add 60 wt% of normal temperature water and 1 wt% sodium lignosulfonate based on the weight of liming bare hide to the drum, rotate for 2 h, adjust the pH of the bath solution to 4.5 with formic acid, and then add 6 wt% chrome-free metal tanning agent TWLZ based on the weight of limed bare hide, continue to rotate for 1 h, use sodium bicarbonate to elevate the alkali to pH 4.5, add 100 wt% hot water based on the weight of limed bare hide, and make The temperature of the bat...

Embodiment 3

[0075]Place the pickled sheepskin obtained by the conventional process in a drum, add 30 wt% of pickling solution and 1 wt% of chrome-free organic tanning agent TWS based on the weight of limed bare hide, rotate for 2 h, and use carbonic acid Sodium and sodium bicarbonate to improve the alkali to pH 7.0, then add hot water of 100 wt% based on the weight of liming bare skins, keep the temperature of the bath at 38°C, rotate for 3 hours, stop the drum overnight, and turn to 0.5% the next day. After one hour, drain the liquid; add 100 wt% normal temperature water and 4 wt% sodium lignosulfonate based on the weight of liming bare hide to the drum, rotate for 0.5 h, adjust the pH of the bath solution to 3.0 with formic acid, and then add 2 wt% chrome-free metal tanning agent TWLZ based on the weight of liming bare hide, continue to rotate for 2.5 h, use sodium carbonate to elevate the alkali to pH 3.5, add 150 wt% hot water based on the weight of liming bare hide, and make the bath ...

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Abstract

The invention belongs to the technical field of leather processing, and discloses an ecological leather chrome-free tanning process which is characterized in that a'TWS + sodium lignin sulfonate + TWLZ 'ternary tanning process system is adopted. By adding the sodium lignin sulfonate, a fixing effect is formed on the TWS tanning agent, so that the TWS tanning leather cannot be subjected to detanning under the condition of low pH, the distribution uniformity of the TWLZ tanning agent in the leather can be remarkably improved, the TWLZ tanning agent is promoted to form a stable cross-linked network structure in leather collagenous fibers, the defects of the tanning performance of an existing tanning system are effectively overcome, and the tanning performance of the tanning system is improved. And the leather which is uniform and sufficient in tanning, high in isoelectric point, strong in positive electricity, good in dyeing and finishing material absorption and soft in leather body is obtained, and the leather is endowed with wider application range and better quality.

Description

technical field [0001] The invention belongs to the technical field of leather processing, in particular to a chrome-free tanning process of ecological leather. Background technique [0002] Eco-leather manufacturing is the most important strategic goal of the global leather industry. The chrome tanning method has become the dominant tanning method in the current leather industry because it can endow the leather with excellent moisture and heat stability and comprehensive performance of the finished leather. However, chrome tanning will produce problems such as chromium-containing wastewater and solid waste, which have potential environmental risks. Therefore, developing a new chrome-free tanning technology for ecological leather and eliminating chrome pollution from the source is a key scientific and technological issue to be solved urgently for the sustainable development of the leather industry. [0003] Chinese patent CN103060488B "A Production Method for Environmental...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C14C3/04C14C3/16C14C3/24C14C3/28
CPCC14C3/04C14C3/16C14C3/24C14C3/28Y02W30/50
Inventor 王亚楠余跃石碧周建飞曾运航张文华
Owner SICHUAN UNIV
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