Ecological tanning method for fur

Abstract

The invention provides an ecological fur tanning method, and relates to the technical field of fur tanning. The ecological fur tanning method specifically comprises the following steps: S1, preparing raw materials; s2, soaking treatment; s3, biological degreasing; s4, carrying out softening treatment; s5, tanning with a bio-based epoxy active tanning agent; s6, tanning liquid management; s7, cleaning and drying; and S8, finishing and modifying. According to the method, the bio-based epoxy active tanning agent is adopted, use of tanning agents capable of releasing harmful substances such as formaldehyde and chromium in the traditional tanning process is avoided, greening of the tanning process is achieved, meanwhile, tanning waste liquid is prone to biochemical treatment, pollution to the environment is reduced, and the tanning agent capable of releasing the harmful substances is not used in the method, so that the tanning process is environmentally friendly. A terminal product does not contain harmful substances such as free formaldehyde or hexavalent chromium, the health and safety are improved, through biological degreasing and moderate enzyme softening in pretreatment, leather fibers are effectively dispersed, permeation and combination of a tanning agent are promoted, the tanning performance is enhanced, and the damp-heat-resistant stability of a leather plate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of fur tanning, in particular to an ecological fur tanning method. Background Art

[0002] Fur refers to animal skin with hair, which is generally used to make clothing, decorations, etc. After proper treatment, the fur is soft and the hair is shiny and elastic, making it a precious natural material. Fur tanning is the process of transforming raw animal skin into a durable and non-perishable material. In traditional tanning methods, chemicals such as formaldehyde or chromium are often used, which are not only harmful to the environment, but also pose a threat to the health of consumers and operators. Eco-tanning aims to reduce or eliminate the use of these harmful substances through more environmentally friendly and safe technical means, thereby protecting the environment and human health, and meeting the needs of modern consumers for green products.

[0003] Existing eco-tanning technologies include the use of formaldehyde-free and chrome-free tanning technology and modified glutaraldehyde tanning technology. However, these methods still have some problems, such as partial release of formaldehyde, or the fur is prone to yellowing. In addition, although these technologies reduce the harm to the environment, they cannot completely eliminate the presence of all harmful substances. Even formaldehyde-free and chrome-free tanning technology may still release a small amount of formaldehyde or aldehyde-containing compounds, and harmful substances cannot be completely eliminated. Some existing tanning technologies, such as modified glutaraldehyde tanning, may cause yellowing of fur, affecting the appearance and quality of the final product. Although existing technologies have been improved, they still have shortcomings in waste liquid treatment and energy consumption, and cannot fully meet green environmental protection standards.

[0004] Therefore, the present invention proposes a fur ecological tanning method to solve the above-mentioned problems. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a fur ecological tanning method, which solves the problem that the prior art has poor quality and may contain residual harmful substances.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a fur ecological tanning method, specifically comprising the following steps:

[0007] S1. Raw material preparation

[0008] Choose high-quality Tan sheepskin as raw material to ensure the leather is healthy and without obvious damage. Tan sheepskin has fine hair, loose skin structure and high fat content, which provides a good foundation for the tanning process.

[0009] S2. Water immersion treatment

[0010] Soak the raw leather in clean water to thoroughly moisten the leather and restore it to a nearly original state for easy subsequent processing;

[0011] S3. Bio-degreasing

[0012] Use biological degreasing agent for treatment, the dosage of degreasing agent is 3-5%, and the biological glycerol component in the bio-based epoxy tanning agent is used to decompose the excess fat in the skin through the active groups modified by epichlorohydrin;

[0013] S4. Softening treatment

[0014] Use enzyme preparations for softening treatment, the dosage of enzyme preparations is 2-3%, the process is carried out at 25-30℃, and the time is 4-6 hours. The softening process can effectively disperse the leather fibers and facilitate the penetration and combination of subsequent tanning agents, ensuring the stability and consistency of the tanning effect;

[0015] S5. Bio-based epoxy reactive tanning agent tanning

[0016] Use bio-based epoxy active tanning agent, the dosage of tanning agent is 5-7%, tanning is carried out under weak alkaline conditions, the pH value is controlled at 8.0-8.5, by adding an appropriate amount of alkaline regulator, the tanning temperature is 30-35℃, the time is 12-16 hours, during the tanning process, the epoxy group combines with the amino group and other alkaline groups on the collagen peptide chain of the skin to form chemical cross-linking, thereby stabilizing the skin fiber structure;

[0017] S6. Tanning liquid management

[0018] The tanning liquid is recycled during use, with the initial dosage being 100-150% of the tare weight, and the subsequent replenishment dosage being 50-70%. The tanning waste liquid can be biochemically treated after treatment, with the pH value adjusted to 7.0-7.5, and decomposed by microorganisms to further reduce the impact of the waste liquid on the environment;

[0019] S7. Cleaning and drying

[0020] After tanning, the leather is washed several times, each time with 200-250% of the leather weight of clean water, the water temperature is controlled at 20-25°C, and the washing time is 30-60 minutes until the tanning liquid is completely removed, and then dried;

[0021] S8. Arrangement and modification

[0022] The tanned and dried leather is sorted and modified. The softness and glossiness of the leather can be adjusted according to needs. During the sorting process, mechanical kneading and polishing can be performed to ensure that the texture of the leather is improved and the beauty of the product is increased.

[0023] Preferably, the sebum content of the fur selected in the raw material preparation in step S1 needs to account for 30% of the fur weight.

[0024] Preferably, the soaking time in the soaking treatment in step S2 is 12 hours, and the water temperature is controlled at 20-25°C.

[0025] Preferably, the degreasing process in the biological degreasing in step S3 is carried out at 30° C. for 6-8 hours to ensure effective decomposition of fat without damaging the skin fibers, thereby ensuring the integrity of the skin fibers.

[0026] Preferably, in step S5, NaOH is used as the alkaline regulator in the tanning of the bio-based epoxy active tanning agent.

[0027] Preferably, in the step S7 of cleaning and drying, the drying temperature is controlled at 40-50° C. for 24-48 hours to restore the leather to its natural state.

[0028] Preferably, the amount of the degreasing agent in the biological degreasing in step S3 is based on the tare weight, the amount of the enzyme preparation in the softening treatment in step S4 is based on the tare weight, and the amount of the tanning agent in the bio-based epoxy active tanning agent tanning in step S5 is based on the tare weight.

[0029] The present invention provides a fur ecological tanning method, which has the following beneficial effects:

[0030] The present invention provides a method for ecological tanning of fur. The method adopts a bio-based epoxy active tanning agent, avoids the use of tanning agents that may release harmful substances such as formaldehyde and chromium, and ensures the greenness of the tanning process. At the same time, the tanning waste liquid is easy to be biochemically treated, reducing pollution to the environment. Since the terminal product does not contain harmful substances such as free formaldehyde or hexavalent chromium, the health of consumers is better protected. At the same time, the health threat of the tanning process to operators is also greatly reduced. In the pretreatment process, through biological degreasing and moderate enzyme softening, the dispersion of leather fibers and the penetration effect of tanning agents are optimized, the tanning performance is enhanced, and finally the moisture and heat stability of the leather board is close to or exceeds the existing process. The recycling of tanning liquid not only reduces the discharge of waste liquid, but also reduces production costs and alleviates the burden on the environment. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] The embodiment of the present invention provides a fur ecological tanning method, which specifically comprises the following steps:

[0034] S1. Raw material preparation

[0035] Choose high-quality Tan sheepskin as raw material to ensure that the leather is healthy and without obvious damage. Tan sheepskin has fine hair, loose skin structure and high fat content (sebum content accounts for 30% of the leather weight), which provides a good foundation for the tanning process;

[0036] S2. Water immersion treatment

[0037] Soak the raw leather in clean water for 12 hours at a temperature of 20°C to thoroughly moisten the leather and restore it to a nearly original state for subsequent processing;

[0038] S3. Bio-degreasing

[0039] The treatment is carried out with a biological degreasing agent, the dosage of which is 3% (based on the tare weight), and the biological glycerol component in the bio-based epoxy tanning agent is used to decompose the excess fat in the skin through the active groups modified by epichlorohydrin. The degreasing process is carried out at 30°C for 6 hours to ensure effective decomposition of fat without damaging the skin fibers, thereby ensuring the integrity of the skin fibers;

[0040] S4. Softening treatment

[0041] Use enzyme preparation for softening treatment, the dosage of enzyme preparation is 2% (based on the tare weight), the softening process is carried out at 25℃ for 4 hours. The softening process can effectively disperse the leather fibers and facilitate the penetration and combination of subsequent tanning agents, ensuring the stability and consistency of the tanning effect;

[0042] S5. Bio-based epoxy reactive tanning agent tanning

[0043] Use bio-based epoxy active tanning agent, the dosage of tanning agent is 5% (based on the skin weight), tanning is carried out under weak alkaline conditions, the pH value is controlled at 8.0, by adding an appropriate amount of alkaline regulator (such as NaOH), the tanning temperature is 30°C, the time is 12 hours, during the tanning process, the epoxy group combines with the amino group and other basic groups on the collagen peptide chain of the skin to form chemical cross-linking, thereby stabilizing the skin fiber structure;

[0044] S6. Tanning liquid management

[0045] The tanning liquid is recycled during use, with the initial dosage being 100% of the tare weight, and the subsequent replenishment dosage being 50%. The tanning waste liquid can be biochemically treated after treatment, with the pH value adjusted to 7.0, and decomposed by microorganisms to further reduce the impact of the waste liquid on the environment;

[0046] S7. Cleaning and drying

[0047] After tanning, the leather is washed several times, each time with 200% of the leather weight using clean water, the water temperature is controlled at 20°C, the washing time is 30 minutes, until the tanning liquid is completely removed, and then dried, the drying temperature is controlled at 40°C, the time is 24 hours, so that the leather returns to its natural state;

[0048] S8. Arrangement and modification

[0049] The tanned and dried leather is sorted and modified. The softness and glossiness of the leather can be adjusted according to needs. During the sorting process, mechanical kneading and polishing can be performed to ensure that the texture of the leather is improved and the beauty of the product is increased.

[0050] Example 2

[0051] The embodiment of the present invention provides a fur ecological tanning method, which specifically comprises the following steps:

[0052] S1. Raw material preparation

[0053] Choose high-quality Tan sheepskin as raw material to ensure that the leather is healthy and without obvious damage. Tan sheepskin has fine hair, loose skin structure and high fat content (sebum content accounts for 30% of the leather weight), which provides a good foundation for the tanning process;

[0054] S2. Water immersion treatment

[0055] Soak the raw leather in clean water for 12 hours, with the water temperature controlled at 23°C, to thoroughly wet the leather and restore it to a nearly original state for subsequent processing;

[0056] S3. Bio-degreasing

[0057] The treatment is carried out with a biological degreasing agent, the dosage of which is 4% (based on the tare weight), and the biological glycerol component in the bio-based epoxy tanning agent is used to decompose the excess fat in the skin through the active groups modified by epichlorohydrin. The degreasing process is carried out at 30°C for 7 hours to ensure effective decomposition of fat without damaging the skin fibers, thereby ensuring the integrity of the skin fibers;

[0058] S4. Softening treatment

[0059] Use enzyme preparation for softening treatment, the dosage of enzyme preparation is 2.5% (based on the tare weight), the softening process is carried out at 27°C for 5 hours. The softening process can effectively disperse the leather fibers and facilitate the penetration and combination of subsequent tanning agents, ensuring the stability and consistency of the tanning effect;

[0060] S5. Bio-based epoxy reactive tanning agent tanning

[0061] Use bio-based epoxy active tanning agent, the dosage of tanning agent is 6% (based on the skin weight), tanning is carried out under weak alkaline conditions, the pH value is controlled at 8.3, by adding an appropriate amount of alkaline regulator (such as NaOH), the tanning temperature is 33°C, the time is 14 hours, during the tanning process, the epoxy group combines with the amino group and other basic groups on the collagen peptide chain of the skin to form chemical cross-linking, thereby stabilizing the skin fiber structure;

[0062] S6. Tanning liquid management

[0063] The tanning liquid is recycled during use, with the initial dosage being 125% of the tare weight, and the subsequent replenishment dosage being 60%. The tanning waste liquid can be biochemically treated after treatment, with the pH value adjusted to 7.3, and decomposed by microorganisms to further reduce the impact of the waste liquid on the environment;

[0064] S7. Cleaning and drying

[0065] After tanning, the leather is washed several times, each time with 225% of the leather weight, the water temperature is controlled at 23°C, the washing time is 45 minutes, until the tanning liquid is completely removed, and then dried, the drying temperature is controlled at 45°C, the time is 36 hours, so that the leather returns to its natural state;

[0066] S8. Arrangement and modification

[0067] The tanned and dried leather is sorted and modified. The softness and glossiness of the leather can be adjusted according to needs. During the sorting process, mechanical kneading and polishing can be performed to ensure that the texture of the leather is improved and the beauty of the product is increased.

[0068] Example 3

[0069] The embodiment of the present invention provides a fur ecological tanning method, which specifically comprises the following steps:

[0070] S1. Raw material preparation

[0071] Choose high-quality Tan sheepskin as raw material to ensure that the leather is healthy and without obvious damage. Tan sheepskin has fine hair, loose skin structure and high fat content (sebum content accounts for 30% of the leather weight), which provides a good foundation for the tanning process;

[0072] S2. Water immersion treatment

[0073] Soak the raw leather in clean water for 12 hours, with the water temperature controlled at 25°C, to thoroughly wet the leather and restore it to a nearly original state for subsequent processing;

[0074] S3. Bio-degreasing

[0075] The treatment is carried out with a biological degreasing agent, the dosage of which is 5% (based on the tare weight), and the biological glycerol component in the bio-based epoxy tanning agent is used to decompose the excess fat in the skin through the active groups modified by epichlorohydrin. The degreasing process is carried out at 30°C for 8 hours to ensure effective decomposition of fat without damaging the skin fibers, thereby ensuring the integrity of the skin fibers;

[0076] S4. Softening treatment

[0077] Use enzyme preparation for softening treatment, the dosage of enzyme preparation is 3% (based on the tare weight), the softening process is carried out at 30℃ for 6 hours. The softening process can effectively disperse the leather fibers and facilitate the penetration and combination of subsequent tanning agents, ensuring the stability and consistency of the tanning effect;

[0078] S5. Bio-based epoxy reactive tanning agent tanning

[0079] Use bio-based epoxy active tanning agent, the dosage of tanning agent is 7% (based on the skin weight), tanning is carried out under weak alkaline conditions, the pH value is controlled at 8.5, by adding an appropriate amount of alkaline regulator (such as NaOH), the tanning temperature is 35°C, the time is 16 hours, during the tanning process, the epoxy group combines with the amino group and other basic groups on the collagen peptide chain of the skin to form chemical cross-linking, thereby stabilizing the skin fiber structure;

[0080] S6. Tanning liquid management

[0081] The tanning liquid is recycled during use, with the initial dosage being 150% of the tare weight, and the subsequent replenishment dosage being 70%. The tanning waste liquid can be biochemically treated after treatment, with the pH value adjusted to 7.5, and decomposed by microorganisms to further reduce the impact of the waste liquid on the environment;

[0082] S7. Cleaning and drying

[0083] After tanning, the leather is washed several times, each time with 250% of the leather weight, the water temperature is controlled at 25°C, the washing time is 60 minutes, until the tanning liquid is completely removed, and then dried at 50°C for 48 hours to restore the leather to its natural state;

[0084] S8. Arrangement and modification

[0085] The tanned and dried leather is sorted and modified. The softness and glossiness of the leather can be adjusted according to needs. During the sorting process, mechanical kneading and polishing can be performed to ensure that the texture of the leather is improved and the beauty of the product is increased.

[0086] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for ecological tanning of fur, characterized in that: The specific steps include: S1. Raw material preparation Choose high-quality Tan sheepskin as raw material to ensure the leather is healthy and without obvious damage. Tan sheepskin has fine hair, loose skin structure and high fat content, which provides a good foundation for the tanning process. S2. Water immersion treatment Soak the raw leather in clean water to thoroughly moisten the leather and restore it to a nearly original state for easy subsequent processing; S3. Bio-degreasing Use biological degreasing agent for treatment, the dosage of degreasing agent is 3-5%, and the biological glycerol component in the bio-based epoxy tanning agent is used to decompose the excess fat in the skin through the active groups modified by epichlorohydrin; S4. Softening treatment Use enzyme preparations for softening treatment, the dosage of enzyme preparations is 2-3%, the process is carried out at 25-30℃, and the time is 4-6 hours. The softening process can effectively disperse the leather fibers and facilitate the penetration and combination of subsequent tanning agents, ensuring the stability and consistency of the tanning effect; S5. Bio-based epoxy reactive tanning agent tanning Use bio-based epoxy active tanning agent, the dosage of tanning agent is 5-7%, tanning is carried out under weak alkaline conditions, the pH value is controlled at 8.0-8.5, by adding an appropriate amount of alkaline regulator, the tanning temperature is 30-35℃, the time is 12-16 hours, during the tanning process, the epoxy group combines with the amino group and other alkaline groups on the collagen peptide chain of the skin to form chemical cross-linking, thereby stabilizing the skin fiber structure; S6. Tanning liquid management The tanning liquid is recycled during use, with the initial dosage being 100-150% of the tare weight, and the subsequent replenishment dosage being 50-70%. The tanning waste liquid can be biochemically treated after treatment, with the pH value adjusted to 7.0-7.5, and decomposed by microorganisms to further reduce the impact of the waste liquid on the environment; S7. Cleaning and drying After tanning, the leather is washed several times, each time with 200-250% of the leather weight of clean water, the water temperature is controlled at 20-25°C, and the washing time is 30-60 minutes until the tanning liquid is completely removed, and then dried; S8. Arrangement and modification The tanned and dried leather is sorted and modified. The softness and glossiness of the leather can be adjusted according to needs. During the sorting process, mechanical kneading and polishing can be performed to ensure that the texture of the leather is improved and the beauty of the product is increased.

2. A method for ecological tanning of fur according to claim 1, characterized in that: The sebum content of the fur selected in the raw material preparation in step S1 must account for 30% of the fur weight.

3. A method for ecological tanning of fur according to claim 1, characterized in that: The soaking time in the soaking treatment in step S2 is 12 hours, and the water temperature is controlled at 20-25°C.

4. A method for ecological tanning of fur according to claim 1, characterized in that: The degreasing process in the biological degreasing in step S3 is carried out at 30° C. for 6-8 hours to ensure effective decomposition of fat without damaging the skin fibers, thereby ensuring the integrity of the skin fibers.

5. A method for ecological tanning of fur according to claim 1, characterized in that: In the step S5, NaOH is used as an alkaline regulator in the tanning of the bio-based epoxy active tanning agent.

6. A method for ecological tanning of fur according to claim 1, characterized in that: In the step S7, the drying temperature is controlled at 40-50°C for 24-48 hours to restore the leather to its natural state.

7. A method for ecological tanning of fur according to claim 1, characterized in that: The amount of the degreasing agent used in the biological degreasing in step S3 is based on the tare weight, the amount of the enzyme preparation used in the softening treatment in step S4 is based on the tare weight, and the amount of the tanning agent used in the bio-based epoxy active tanning agent tanning in step S5 is based on the tare weight.