After-tanning wet finishing manufacturing process of washable vegetable leather

Abstract

The invention relates to an after-tanning wet finishing manufacturing process of washable vegetable leather. The after-tanning wet finishing manufacturing process comprises the following steps of washing, retanning and fat liquoring. The method comprises the following steps: by taking pure vegetable tanned wet white leather as a raw material, adding oxalic acid and 0.3-0.5% of an iron removal agent, and rotating for 40 minutes; draining water; adding a protein filler, white tannin, a fish oil fatting agent, a wattle bark tannin extract, a plant tannin extract and replacement tannin; adding a bio-based fluoride-free waterproof agent; and adding a fatting agent, fish oil, formic acid and a bio-based fluoride-free waterproof agent. According to the after-tanning wet finishing manufacturing process, the bio-based fluoride-free waterproof agent is used for filling after fat liquoring, a protective layer is formed on the surface of leather fiber, and the washing resistance of vegetable leather is improved; a bio-based fluoride-free waterproof agent is added in the after-tanning wet finishing process, so that the washing resistance of the vegetable leather is improved, and the cleanability of the vegetable leather product is enhanced; the bio-based fluoride-free waterproof agent takes natural plants and derivatives thereof as production raw materials, and has the advantages of low carbon emission and environmental protection compared with original chemical materials.

Description

Technical Field

[0001] The invention relates to the technical field of leather manufacturing, in particular to a post-tanning wet finishing manufacturing process for washable vegetable tanned leather. Background Art

[0002] With the advancement of industrialization, the country's requirements for the current chemical industry are to accelerate the green transformation of development methods, implement a comprehensive conservation strategy, develop green and low-carbon industries, advocate green consumption, and promote the formation of green and low-carbon production methods and lifestyles. In the Guiding Opinions on the Development of the Leather Industry (2021-2025), the level of green manufacturing will be improved, and the research and development and industrialization of chrome-free tanning agents and tanning technologies will be strengthened as the key development direction of the leather industry.

[0003] As the earliest leather tanning method, vegetable tanning has a long history of development. Vegetable tanning uses natural vegetable tanning agents, does not contain heavy metals, benzene, phenol and other harmful substances, and is harmless to the human body and the environment. Compared with chemical tanning methods, the vegetable tanning process produces less pollutants such as wastewater and waste gas, and is easy to handle, which is beneficial to protecting the ecological environment. Vegetable tanned leather has the characteristics of good formability, plump and elastic board surface, no greasy feeling, and the grain and suede of the leather are shiny. However, vegetable tanned leather also has the disadvantage of poor bonding between tanning agents and collagen fibers, which makes vegetable tanned leather not resistant to water washing, and long-term water washing will cause it to de-tannage.

[0004] In the field of leather waterproofing, the use of waterproofing agents has a long history. Early waterproof leather mainly relied on fluorine-containing waterproofing agents, which can form a dense fluorinated surface layer on the leather surface, giving the leather excellent waterproof properties. However, with the increase in environmental awareness, people have begun to pay attention to the potential impact of monomers perfluorooctanoic acid (PFOA) and perfluorooctane sulfonyl compounds (PFOS) in fluorine-containing waterproofing agents on the environment. Therefore, fluorine-free waterproofing agents that do not contain PFOA and PFOS have gradually received attention and become a green alternative to fluorine-containing waterproofing agents. In view of this, this case came into being. Summary of the invention

[0005] The invention provides a post-tanning wet finishing manufacturing process for washable vegetable tanned leather, so as to overcome the problems existing in the use of waterproofing agents for the above-mentioned waterproof leather.

[0006] The present invention adopts the following technical solution:

[0007] A post-tanning wet finishing manufacturing process for washable vegetable tanned leather comprises the following steps: washing → retanning → fatliquoring;

[0008] Washing: Use pure vegetable tanned wet leather as raw material, wash it according to the conventional process, add 80%-100% water to the drum, add 0.3%-0.5% oxalic acid, add 0.3%-0.5% iron remover, and rotate for 40 minutes; drain;

[0009] Retanning: add 30%-50% water to the drum, add 1%-2% protein filler, add 1%-2% white tannin, and rotate for 15 minutes; add 1%-2% fish oil fatliquor, and rotate for 20 minutes; add 3%-5% wattle bark tannin, add 3%-5% vegetable tannin, replace tannin 1%-2%, and rotate for 60 minutes; add 1%-2% resin retanning agent, add 1%-2% dicyandiamide resin retanning agent, and rotate for 60 minutes; add 1%-2% dicyandiamide resin retanning agent, add 1%-2% resin retanning agent, and rotate for 60 minutes, add 1%-2% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes;

[0010] Fatting: add 30%-50% water to the drum, the temperature is 50℃, add 11%-13% fatliquor, add 1%-3% fish oil, and rotate for 50 minutes; add 0.3%-0.5% formic acid, and rotate for 10 minutes; add 0.8%-1.0% formic acid, and rotate for 20 minutes; drain; add 50%-60% water, the temperature is 25℃, add 3%-5% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes.

[0011] Furthermore, the above-mentioned washing: pure vegetable tanned white wet leather is used as raw material, and washing treatment is carried out according to conventional processes, 100% water is added to the drum, the temperature is 35°C, 0.5% oxalic acid is added, 0.5% iron remover is added, and the drum is rotated for 40 minutes; and drainage is carried out.

[0012] Furthermore, the above retanning: add 50% water to the drum, add 2% protein filler, add 2% white tannin, and rotate for 15 minutes; add 2% fish oil fatliquor, and rotate for 20 minutes; add 5% wattle bark tannin, add 5% vegetable tannin, replace 2% tannin, and rotate for 60 minutes; add 2% resin retanning agent, add 2% dicyandiamide resin retanning agent, and rotate for 60 minutes; add 2% dicyandiamide resin retanning agent, add 2% resin retanning agent, and rotate for 60 minutes, add 2% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes.

[0013] Furthermore, the above-mentioned fatliquoring: add 50% water to the drum, the temperature is 50°C, add 11% fatliquor, add 3% fish oil, and rotate for 50 minutes; add 0.5% formic acid, and rotate for 10 minutes; add 0.8% formic acid, and rotate for 20 minutes; drain; add 50% water, the temperature is 25°C, add 3% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes.

[0014] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following advantages:

[0015] 1. The post-tanning wet finishing manufacturing process of the present application uses a bio-based fluorine-free waterproofing agent in the post-tanning wet finishing. This bio-based fluorine-free waterproofing agent is a natural waterproofing agent modified from natural palm oil and its derivatives with acrylic acid. Its raw materials are green and degradable and have little pollution to the environment. In the modification process, a directional arrangement technology is used to make the waterproof groups on the fiber surface more compact and regular to obtain a better waterproof effect. The use of the bio-based fluorine-free waterproofing agent replaces the original acrylic acid to obtain a set of water-washable post-tanning wet finishing process technology for vegetable tanned leather.

[0016] 2. The post-tanning wet finishing manufacturing process of the present application uses a bio-based fluorine-free waterproofing agent for filling after greasing to form a protective layer on the surface of the leather fibers, thereby increasing the water-washing resistance of the vegetable tanned leather; the addition of a bio-based fluorine-free waterproofing agent in the post-tanning wet finishing process improves the water-washing resistance of the vegetable tanned leather and enhances the cleanability of the vegetable tanned leather products; the bio-based fluorine-free waterproofing agent uses natural plants and their derivatives as raw materials for production, and has the advantages of low carbon emissions and green environmental protection compared to the original chemical materials. DETAILED DESCRIPTION

[0017] Embodiment 1:

[0018] A post-tanning wet finishing manufacturing process for washable vegetable tanned leather comprises the following steps: washing → retanning → fatliquoring;

[0019] The above-mentioned washing: pure vegetable tanned white wet leather is used as raw material, and washing treatment is carried out according to conventional technology, 100% water is added to the drum, the temperature is 35°C, 0.5% oxalic acid is added, 0.5% iron remover is added, and the drum is rotated for 40 minutes; drainage is carried out.

[0020] The above retanning: add 50% water to the drum, add 2% protein filler, add 2% white tannin, and rotate for 15 minutes; add 2% fish oil fatliquor, and rotate for 20 minutes; add 5% wattle bark tannin, add 5% vegetable tannin, replace 2% tannin, and rotate for 60 minutes; add 2% resin retanning agent, add 2% dicyandiamide resin retanning agent, and rotate for 60 minutes; add 2% dicyandiamide resin retanning agent, add 2% resin retanning agent, and rotate for 60 minutes, add 2% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes.

[0021] The above-mentioned fatliquoring: add 50% water to the drum, the temperature is 50°C, add 11% fatliquor, add 3% fish oil, and rotate for 50 minutes; add 0.5% formic acid, and rotate for 10 minutes; add 0.8% formic acid, and rotate for 20 minutes; drain; add 50% water, the temperature is 25°C, add 3% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes.

[0022] Embodiment 2:

[0023] A post-tanning wet finishing manufacturing process for washable vegetable tanned leather comprises the following steps: washing → retanning → fatliquoring;

[0024] Washing: Use pure vegetable tanned wet leather as raw material, wash it according to the conventional process, add 80% water to the drum, add 0.3% oxalic acid, add 0.3% iron remover, and rotate for 40 minutes; drain;

[0025] Retanning: add 30% water to the drum, add 1% protein filler, add 1% white tannin, rotate for 15 minutes; add 1% fish oil fatliquor, rotate for 20 minutes; add 3% wattle bark tannin, add 3% vegetable tannin, replace 1% tannin, rotate for 60 minutes; add 1% resin retanning agent, add 1% dicyandiamide resin retanning agent, rotate for 60 minutes; add 1% dicyandiamide resin retanning agent, add 1% resin retanning agent, rotate for 60 minutes, add 1% bio-based fluorine-free waterproofing agent, rotate for 60 minutes;

[0026] Fatting: add 30% water to the drum, temperature 50℃, add 11% fatliquor, add 1% fish oil, rotate for 50 minutes; add 0.3% formic acid, rotate for 10 minutes; add 0.8% formic acid, rotate for 20 minutes; drain; add 50% water, temperature 25℃, add 3% bio-based fluorine-free waterproofing agent, rotate for 60 minutes.

[0027] The post-tanning wet finishing manufacturing process (improved process) of the washable vegetable tanned leather of the present application is compared with the original process, as follows:

[0028] Table 1 Process comparison table

[0029]

[0030] In the original process, Q-307 and R83 are both acrylic acid

[0031] The performance test of the vegetable tanned crust leather obtained in Example 1 was compared with that of the crust leather obtained by the original process, as follows:

[0032] Table 1 Comparison of properties of vegetable tanned leather

[0033]

[0034] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A post-tanning wet finishing manufacturing process for washable vegetable tanned leather, characterized in that: The steps include: Washing → retanning → fatliquoring; Washing: Use pure vegetable tanned wet leather as raw material, wash it according to the conventional process, add 80%-100% water to the drum, add 0.3%-0.5% oxalic acid, add 0.3%-0.5% iron remover, and rotate for 40 minutes; drain; Retanning: add 30%-50% water to the drum, add 1%-2% protein filler, add 1%-2% white tannin, and rotate for 15 minutes; add 1%-2% fish oil fatliquor, and rotate for 20 minutes; add 3%-5% wattle bark tannin, add 3%-5% vegetable tannin, replace tannin 1%-2%, and rotate for 60 minutes; add 1%-2% resin retanning agent, add 1%-2% dicyandiamide resin retanning agent, and rotate for 60 minutes; add 1%-2% dicyandiamide resin retanning agent, add 1%-2% resin retanning agent, and rotate for 60 minutes, add 1%-2% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes; Fatting: add 30%-50% water to the drum, the temperature is 50℃, add 11%-13% fatliquor, add 1%-3% fish oil, and rotate for 50 minutes; add 0.3%-0.5% formic acid, and rotate for 10 minutes; add 0.8%-1.0% formic acid, and rotate for 20 minutes; drain; add 50%-60% water, the temperature is 25℃, add 3%-5% bio-based fluorine-free waterproofing agent, and rotate for 60 minutes.

2. A process for wet finishing of washable vegetable tanned leather after tanning as claimed in claim 1, characterized in that: The washing process comprises taking pure vegetable tanned white wet leather as raw material, washing the leather according to conventional process, adding 100% water into the drum, setting the temperature to 35° C., adding 0.5% oxalic acid, adding 0.5% iron remover, and rotating the drum for 40 minutes; and draining the water.

3. A process for wet finishing of washable vegetable tanned leather after tanning as claimed in claim 1, characterized in that: The retanning process comprises the following steps: adding 50% water to a rotating drum, adding 2% protein filler, adding 2% white tannin, and rotating for 15 minutes; adding 2% fish oil fatliquor, and rotating for 20 minutes; adding 5% wattle bark tannin, adding 5% vegetable tannin, and replacing 2% tannin, and rotating for 60 minutes; adding 2% resin retanning agent, adding 2% dicyandiamide resin retanning agent, and rotating for 60 minutes; adding 2% dicyandiamide resin retanning agent, adding 2% resin retanning agent, and rotating for 60 minutes; adding 2% bio-based fluorine-free waterproofing agent, and rotating for 60 minutes.

4. A process for wet finishing of washable vegetable tanned leather after tanning as claimed in claim 1, characterized in that: The fatliquoring comprises the following steps: adding 50% water to a drum at a temperature of 50° C., adding 11% fatliquor, adding 3% fish oil, and rotating for 50 minutes; adding 0.5% formic acid, and rotating for 10 minutes; adding 0.8% formic acid, and rotating for 20 minutes; draining the water; adding 50% water, at a temperature of 25° C., adding 3% bio-based fluorine-free waterproofing agent, and rotating for 60 minutes.

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