Cowhide mat pure vegetable tanning process

Abstract

The invention belongs to the technical field of leather materials, and particularly discloses a cow leather mat pure vegetable tanning process which comprises a water soaking procedure, an alkali soaking procedure, a re-liming procedure and a tanning procedure. The water soaking process is used for recovering water of the cow leather and removing dirt; the soaking process comprises pre-soaking treatment and main soaking treatment; the alkali soaking process is used for separating epidermis from dermis to loosen collagenous fibers; the re-liming process is used for the supplementary treatment process after the alkali leaching process to loosen collagen fibers; the tanning process is used for combining a tanning agent with collagenous fibers; and the tanning process comprises primary tanning treatment and retanning treatment. The leather of the cowhide mat produced by the process is full and elastic in handfeel, and no heavy metal dye is added, so that heavy metals are prevented from existing in the prepared cowhide mat.

Description

Technical Field

[0001] The invention belongs to the technical field of leather materials, and in particular relates to a pure vegetable tanning process for cowhide mats. Background Art

[0002] At present, there are three main tanning processes for cowhide: chrome tanning, aldehyde tanning, and vegetable tanning. Chrome tanning uses chromium compounds (such as chromium sulfate) as the main tanning agent. Through the cross-linking of trivalent chromium complexes with leather collagen fibers, the leather has the characteristics of softness, lightness, and excellent elasticity. The finished product is resistant to water washing and storage, and the shrinkage temperature can reach above 100°C. Aldehyde tanning uses formaldehyde (formalin) or glutaraldehyde aqueous solution as a tanning agent. The main feature is good water resistance. The finished product has a hard texture and is not easy to deform. It is suitable for making products that require wear resistance, such as shoes, leather goods, etc. Vegetable tanning uses plant extracts (such as tannin extract). The finished product has a tough and thick texture and is easy to shape after absorbing water. The color gradually deepens with oxidation over time. It is suitable for scenes with high durability requirements such as military products, mechanical parts, and soles.

[0003] In cowhide mat products, since the leather needs to have soft and elastic properties, chrome tanning process is usually used to achieve this. However, heavy metal chromium exists in cowhide mat products, which can cause harm to the human body.

[0004] Moreover, the thickness of the cowhide mats currently on the market is only about 3mm, and the feel is not good, lacking the fleshy and leathery feel. Summary of the Invention

[0005] The purpose of the present invention is to provide a pure vegetable tanning process for cowhide mats, which does not add any heavy metal dyes and makes the leather feel rich and elastic.

[0006] In order to achieve the above-mentioned object, the technical solution of the present invention is as follows: a pure vegetable tanning process for cowhide mats, comprising a soaking process, an alkali soaking process, a re-liming process and a tanning process; the soaking process is used to restore the moisture of the cowhide and remove dirt; the alkali soaking process is used to separate the epidermis and dermis, loosening the collagen fibers; the re-liming process is used as a supplementary treatment process after the alkali soaking process, loosening the collagen fibers; the tanning process is used to combine the tanning agent with the collagen fibers; the tanning process includes a primary tanning process and a re-tanning process;

[0007] The primary tanning process comprises the following steps:

[0008] (1) Add the following substances to a container containing cowhide, based on the total weight of the cowhide: 120-180 wt% of room temperature water, 1.5-2.5 wt% of lime, 0.2-0.4 wt% of sodium sulfide, 0.2-0.4 wt% of sodium hydrosulfide, and 0.4-0.6 wt% of a liming agent; after 7-12 hours, wash the cowhide with running water;

[0009] (2) placing the cowhide obtained in step (1) into a drum, and adding the following substances into the drum, based on the total mass of the cowhide: 0.5-1.5 wt% of a deliming agent, 0.2-0.4 wt% of a degreasing agent, 2-4 wt% of ammonium sulfate, and 0.4-0.6 wt% of a softening enzyme, and rotating the drum for 400-450 minutes; after the drum is rotated, washing the cowhide with water at room temperature;

[0010] (3) placing the cowhide obtained in step (2) into a drum, and adding the following substances into the drum, based on the total mass of the cowhide: 5-7 wt% of salt, 5-7 wt% of sodium sulfate, 0.5-1.5 wt% of a fatliquor, and 1-2 wt% of sulfuric acid, and rotating the drum for 20-40 minutes;

[0011] (4) Continue to add the following substances to the drum, based on the total weight of the cowhide: 0.1-0.3 wt% of acid protease, rotate the drum for 1.5-3 hours and beat for 7-12 hours;

[0012] (5) Continue to add the following substances to the drum, based on the total weight of the cowhide: 3-5 wt% glutaraldehyde, and rotate the drum and beat for 200-400 minutes;

[0013] (6) Continue to add the following substances to the drum, based on the total weight of the cowhide: 0.5-1.5 wt% of an alkali extracting agent and 1.5-2.5 wt% of baking soda, rotate the drum for 100-150 minutes and beat for 32-40 hours;

[0014] (7) After 20-28 hours, wash with water after taking out the drum;

[0015] The retanning process comprises the following steps:

[0016] (1) Adding the primary tanned cowhide into a drum, and adding the following substances into the drum, based on the total mass of the cowhide: 120-180 wt% of room temperature water, 0.4-0.6 wt% of a fatliquor, 1-2 wt% of fish oil, 0.2-0.4 wt% of a complexing agent, and 1.3-1.7 wt% of dispersed tannins, and rotating the drum for 15-25 minutes;

[0017] (2) adding the following substances to the drum three times, based on the total weight of the cowhide: 8-12 wt% of wattle bark extract, 4-6 wt% of saccharified quebracho tannin, 1-3 wt% of chestnut tannin, and 2-4 wt% of bayberry tannin; adding once a day, rotating the drum and beating for 40-80 minutes after each addition; after the last addition, rotating the drum and beating for 20-28 hours;

[0018] (3) Wash the cowhide with water at room temperature, add 2-4 wt% hydrogen peroxide in a drum, and rotate the drum for 100-140 minutes;

[0019] (4) Add the following substances to the drum, based on the total weight of the cowhide: 0.5-1.5 wt% oxalic acid, and rotate the drum for 60-120 minutes;

[0020] (5) Washing the cowhide and heating it to 40-50°C. Add the following substances to the drum, based on the total weight of the cowhide: 1.5-2.5 wt% of animal purified protein, and rotate the drum for 15-25 minutes;

[0021] (6) adding the following substances, based on the total weight of the cowhide, into a drum: 1.5-2.5 wt% neatsfoot oil, 6-8 wt% fish oil, 0.4-0.6 wt% vegetable oil, 1.5-2.5 wt% animal fat, 1.3-1.7 wt% fatliquor, 0.4-0.6 wt% dispersed tannin, 0.2-0.4 wt% complexing agent, 0.4-0.6 wt% baking soda, 0.0.5-0.07 wt% mildew inhibitor, and 0.5-1.5 wt% formaldehyde scavenger, and rotating the drum and beating for 40-80 minutes;

[0022] (7) After 6-12 hours, the following substances are added to the drum, based on the total mass of the cowhide: 0.5-1.5 wt% of macromolecular acrylic acid and 2-4 wt% of micromolecular acrylic acid; the drum is rotated for 400-440 minutes; after the rotation, the cowhide is washed with room temperature water, with a liquid retention ratio of 180-220 wt%.

[0023] (8) Add the following substances into the drum, based on the total weight of the cowhide: 0.15-0.25 wt% of a complexing agent, 0.02-0.06 wt% of a preservative, and 0.03-0.07 wt% of baking soda, and rotate the drum for 8-12 minutes before removing the drum.

[0024] Furthermore, the immersion process includes a pre-immersion treatment and a main immersion treatment;

[0025] The pre-soaking treatment comprises the following steps:

[0026] (1) Put the cowhide into a drum, and add the following substances into the drum, based on the total mass of the cowhide: 250-350wt% of room temperature water, 0.2-0.4wt% of a fungicide, 0.05-0.15wt% of a soaking agent, and 0.2-0.4wt% of soda ash. The drum is rotated for 20-40 minutes and then stopped for 20-40 minutes, and repeated 4-6 times; wherein the fungicide is added twice, with an interval of 5-7 hours between the two times;

[0027] (2) After 10-15 hours, pour out the hide and remove the flesh;

[0028] The main immersion treatment includes: placing the cowhide into a rotary drum, and adding the following substances into the drum, based on the total mass of the cowhide: 150-250wt% of room temperature water, 0.1-0.2wt% of a fungicide, 0.1-0.3wt% of a immersion aid, 0.05-0.15wt% of a immersion agent, 0.1-0.3wt% of a degreasing agent and 0.3-0.7wt% of soda ash; rotating the drum and beating for 20-40 minutes, then stopping for 20-40 minutes, and repeating 1-3 times.

[0029] Furthermore, the alkali leaching process comprises the following steps:

[0030] (1) After 8-12 hours of soaking, the cowhide is washed and drained, leaving 2-4 wt% of water and placed in a drum. The following substances are added to the drum, based on the total weight of the cowhide: 0.1-0.3 wt% of liming enzyme, 0.4-0.6 wt% of liming auxiliary agent, and 0.4-0.6 wt% of sodium hydrosulfide. The drum is rotated for 20-40 minutes and then stopped for 20-40 minutes;

[0031] (2) Add the following substances into the drum, based on the total weight of the cowhide: 0.4-0.6 wt% of sodium sulfide, 0.1-0.3 wt% of a degreasing agent, and 0.4-0.6 wt% of lime, and rotate the drum for 20-40 minutes and then stop for 20-40 minutes;

[0032] (3) Add the following substances into the drum, based on the total weight of the cowhide: 0.5-1.5 wt% of sodium sulfide, 0.5-1.5 wt% of lime, and 0.05-0.15 wt% of a penetrant, and rotate and beat the cowhide for 15-25 minutes, then rest for 30-50 minutes, and repeat 2-4 times;

[0033] (4) Add the following substances into the drum, based on the total weight of the cowhide: 0.5-1.5 wt% of lime, 0.15-0.25 wt% of a liming agent, rotate and beat the drum for 15-25 minutes, then rest for 30-50 minutes, and repeat 2-4 times;

[0034] (5) Add the following substances into the drum, based on the total mass of the cowhide: 70-90wt% of room temperature water, 0.05-0.15wt% of a degreasing agent, 1-3wt% of lime, and 0.05-0.15wt% of a penetrant. The drum is rotated and beaten for 3-7 minutes, then stopped for 20-30 minutes before proceeding to the next step.

[0035] Furthermore, the re-ashing process includes the following steps:

[0036] (1) Add the following substances into the drum, based on the total weight of the cowhide: 0.2-0.4 wt% of the swelling agent, rotate for 4-6 minutes, then stop for 20-30 minutes, and repeat 7-9 times;

[0037] (2) Add the following substances into the drum, based on the total mass of the cowhide: 0.05-0.15 wt% of a degreasing agent, 0.1-0.3 wt% of a liming aid, 2-4 wt% of lime, and 100-140 wt% of water at room temperature. The drum is rotated for 2-4 minutes, stopped for 25-30 minutes, and beaten for 7-12 hours.

[0038] Furthermore, in steps (3) and (4) of the alkali leaching process, it is necessary to detect the temperature inside the drum.

[0039] Furthermore, the pH value needs to be tested before the drum is taken out.

[0040] The beneficial effects of this technical solution are:

[0041] ① The leather of the cowhide mat produced by this process has a rich and elastic feel, and no heavy metal dyes are added to avoid the presence of heavy metals in the prepared cowhide mat.

[0042] ② The cowhide mat produced by this process can be as thick as 5mm and still be soft, plump and elastic. Most cowhide mats on the market can only be 3mm thick, and their hand feel is not as good as that of the cowhide mat produced by this process. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a flow chart of the pure vegetable tanning process of cowhide mats. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 efforts are within the scope of protection of the present invention.

[0045] The embodiment is basically as shown in the attached Figure 1 The pure vegetable tanning process for cowhide mats is shown, consisting of soaking, alkali soaking, re-liming, and tanning. The soaking process restores moisture to the hide and removes contaminants; it includes a pre-soaking and a main soaking process. The alkali soaking separates the epidermis and dermis, loosening the collagen fibers. The re-liming process is a supplementary treatment after the alkali soaking process, loosening the collagen fibers. The tanning process combines the tanning agent with the collagen fibers and includes a primary tanning and a re-tanning process.

[0046] S1: Pre-immersion treatment; including the following steps:

[0047] (1) Put the cowhide into a drum, and add the following substances into the drum, based on the total mass of the cowhide: 250-350wt% (specifically 300wt%) of room temperature water, 0.2-0.4wt% (specifically 0.3wt%) of a fungicide, 0.05-0.15wt% (specifically 0.10wt%) of a soaking agent, and 0.2-0.4wt% (specifically 0.30wt%) of soda ash. The drum is rotated for 20-40 minutes (specifically 30 minutes) and then stopped for 20-40 minutes (specifically 30 minutes), and this is repeated 4-6 times (specifically 5 times); wherein the fungicide is added in two times, with an interval of 5-7 hours (specifically 6 hours) between the two times.

[0048] (2) After 10-15 hours, pour out the hide and remove the flesh.

[0049] S2: Main immersion treatment; comprising: placing the cowhide into a rotary drum, and adding the following substances into the drum, based on the total mass of the cowhide: 150-250wt% (specifically 200wt%) of normal temperature water, 0.1-0.2wt% (specifically 0.15wt%) of fungicide, 0.1-0.3wt% (specifically 0.20wt%) of ES strong immersion aid, 0.05-0.15wt% (specifically 0.10wt%) of immersion agent, 0.1-0.3wt% (specifically 0.20wt%) of degreasing agent and 0.3-0.7wt% (specifically 0.50wt%) of soda ash; the drum is rotated and beaten for 20-40 minutes (specifically 30 minutes), then stopped for 20-40 minutes (specifically 30 minutes), and repeated 1-3 times (specifically 2 times).

[0050] S3: alkali leaching process; comprising the following steps:

[0051] (1) After 8-12 hours of soaking process, the cowhide is washed and drained, and 2-4 wt% (specifically 3 wt%, based on the total mass of the cowhide) of water is retained after drying and placed in a rotary drum. The following substances are added to the drum, based on the total mass of the cowhide: 0.1-0.3 wt% (specifically 0.20 wt%) of SDP strong liming enzyme, 0.4-0.6 wt% (specifically 0.50 wt%) of EA strong liming auxiliary agent and 0.4-0.6 wt% (specifically 0.50 wt%) of sodium hydrosulfide. The drum is rotated for 20-40 minutes (specifically 30 minutes) and then stopped for 20-40 minutes (specifically 30 minutes).

[0052] (2) Add the following substances into the drum, based on the total mass of the cowhide: 0.4-0.6wt% (specifically 0.50wt%) of sodium sulfide, 0.1-0.3wt% (specifically 0.20wt%) of degreasing agent, and 0.4-0.6wt% (specifically 0.50wt%) of lime. The drum is rotated for 20-40 minutes (specifically 30 minutes) and then stopped for 20-40 minutes (specifically 30 minutes).

[0053] (3) Add the following substances to the drum, based on the total weight of the hide: 0.5-1.5 wt% (specifically 1 wt%) of sodium sulfide, 0.5-1.5 wt% (specifically 1 wt%) of lime, and 0.05-0.15 wt% (specifically 0.10 wt%) of JFC penetrant. Rotate and beat the drum for 15-25 minutes (specifically 20 minutes), then rest for 30-50 minutes (specifically 40 minutes). Repeat this process 2-4 times (specifically 3 times). The temperature inside the drum should be monitored.

[0054] (4) Add the following substances to the drum, based on the total weight of the hide: 0.5-1.5 wt% (specifically 1 wt%) of lime, 0.15-0.25 wt% (specifically 0.2 wt%) of L209 liming aid. Rotate and beat the hide for 15-25 minutes (specifically 20 minutes), then rest for 20-40 minutes (specifically 30 minutes). Repeat this process 2-4 times (specifically 3 times). The temperature inside the drum should be monitored.

[0055] (5) Add the following substances into the drum, based on the total mass of the cowhide: 70-90wt% (specifically 80wt%) of room temperature water, 0.05-0.15wt% (specifically 0.10wt%) of degreasing agent, 1-3wt% (specifically 2wt%) of lime and 0.05-0.15wt% (specifically 0.10wt%) of JFC penetrant. The drum is rotated and beaten for 3-7 minutes (specifically 5 minutes), then stopped for 20-30 minutes (specifically 25 minutes) before proceeding to the next step.

[0056] S4: Re-ashing process; including the following steps:

[0057] (1) Add the following substances into the drum, based on the total mass of the cowhide: 0.2-0.4wt% (specifically 0.30wt%) of the expander, rotate for 4-6 minutes (specifically 5 minutes), then stop for 20-30 minutes (specifically 25 minutes), and repeat 7-9 times (specifically 8 times).

[0058] (2) Add the following substances into the drum, based on the total mass of the cowhide: 0.05-0.15wt% (specifically 0.10wt%) of degreasing agent, 0.1-0.3wt% (specifically 0.20wt%) of L209 liming auxiliary agent, 2-4wt% (specifically 3wt%) of lime and 100-140wt% (specifically 120wt%) of room temperature water. The drum is rotated for 2-4 minutes (specifically 3 minutes) and stopped for 25-30 minutes (specifically 27 minutes), and then beaten for 7-12 hours.

[0059] S5: Primary tanning treatment; comprising the following steps:

[0060] (1) Add the following substances into a rotating drum, based on the total mass of the cowhide: 120-180 wt% (specifically 150 wt%) of room temperature water, 1.5-2.5 wt% (specifically 2 wt%) of lime, 0.2-0.4 wt% (specifically 0.3 wt%) of sodium sulfide, 0.2-0.4 wt% (specifically 0.3 wt%) of sodium hydrosulfide, and 0.4-0.6 wt% (specifically 0.5 wt%) of L209 liming aid; after 7-12 hours, wash the cowhide with running water, and raise the water temperature to 33°C.

[0061] (2) Put the cowhide into a drum, and add the following substances into the drum, based on the total mass of the cowhide: 0.5-1.5wt% (specifically 1wt%) of a deliming agent, 0.2-0.4wt% (specifically 0.3wt%) of a degreasing agent, 2-4wt% (specifically 3wt%) of ammonium sulfate, and 0.4-0.6wt% (specifically 0.5wt%) of a softening enzyme. The drum is rotated for 400-450 minutes (specifically 420 minutes); after the rotation, the cowhide is washed with water at room temperature.

[0062] (3) The cowhide prepared in step (2) is placed in a drum, and the following substances are added to the drum, based on the total mass of the cowhide: 5-7wt% (specifically 6wt%) of salt, 5-7wt% (specifically 6wt%) of Glauber's salt, 0.5-1.5wt% (specifically 1wt%) of LQ-5 fatliquor, and 1-2wt% (specifically 1.5wt%) of sulfuric acid, and the drum is rotated for 20-40 minutes (specifically 30 minutes).

[0063] (4) The following substances are continuously added to the drum, based on the total mass of the cowhide: 0.1-0.3 wt% (specifically 0.2 wt%) of BE acid protease, the drum is rotated for 1.5-3 hours (specifically 2 hours) and beaten for 7-12 hours.

[0064] (5) The following substances are continuously added to the drum, based on the total mass of the cowhide: 3-5 wt% (specifically 4 wt%) of GT50 glutaraldehyde, and the drum is rotated and beaten for 200-400 minutes (specifically 300 minutes).

[0065] (6) Continue to add the following substances into the drum, based on the total mass of the cowhide: 0.5-1.5wt% (specifically 1wt%) of MO neutral alkali agent and 1.5-2.5wt% (specifically 2wt%) of baking soda, rotate the drum for 100-150 minutes (specifically 120 minutes) and beat for 32-40 hours (specifically 36 hours).

[0066] (7) After 20-28 hours, remove from drum and wash with water.

[0067] S6: retanning process; comprising the following steps:

[0068] (1) Add the primary tanned cowhide into a drum, and add the following substances into the drum, based on the total mass of the cowhide: 120-180 wt% (specifically 150 wt%) of room temperature water, 0.4-0.6 wt% (specifically 0.5 wt%) of LQ-5 fatliquor, 1-2 wt% (specifically 1.5 wt%) of HFK-N fish oil, 0.2-0.4 wt% (specifically 0.3 wt%) of EDTA complexing agent, and 1.3-1.7 wt% (specifically 1.5 wt%) of 308 dispersed tannin, and rotate the drum for 15-25 minutes (specifically 20 minutes).

[0069] (2) Add the following substances to the drum three times, based on the total mass of the cowhide: 8-12wt% (specifically 10wt%) of FS wattle bark tannin, 4-6wt% (specifically 5wt%) of ATO saccharified quebracho tannin, 1-3wt% (specifically 2wt%) of chestnut tannin and 2-4wt% (specifically 3wt%) of bayberry tannin; add once a day, and after each addition, rotate the drum and beat for 40-80 minutes (specifically 60 minutes); after the last addition, rotate the drum and beat for 20-28 hours (specifically 24 hours).

[0070] (3) After washing the cowhide with water at room temperature, 2-4 wt% (specifically 3 wt%) of hydrogen peroxide is added to a drum, and the drum is rotated for 100-140 minutes (specifically 120 minutes).

[0071] (4) Add the following substances into the drum, based on the total mass of the cowhide: 0.5-1.5 wt% (specifically 1 wt%) of oxalic acid, and rotate the drum for 60-120 minutes (specifically 90 minutes).

[0072] (5) Washing cowhide and heating it to 40-50°C. Add the following substances into the drum, based on the total mass of the cowhide: 1.5-2.5 wt% (specifically 2 wt%) of PWN animal purified protein, and rotate the drum for 15-25 minutes (specifically 20 minutes).

[0073] (6) Add the following substances into the drum, based on the total weight of the cowhide: 1.5-2.5wt% (specifically 2wt%) of F-22, 6-8wt% (specifically 7wt%) of HFK-N fish oil, 0.4-0.6wt% (specifically 0.5wt%) of SS vegetable oil, 1.5-2.5wt% (specifically 2wt%) of A-22 animal oil, 1.3-1.7wt% (specifically 1.5wt%) of LQ-5 fatliquor, 0 .4-0.6wt% (specifically 0.5wt%) of 308 dispersed tannin, 0.2-0.4wt% (specifically 0.3wt%) of EDTA complexing agent, 0.4-0.6wt% (specifically 0.5wt%) of baking soda, 0.0.5-0.07wt% (specifically 0.06wt%) of mildew inhibitor and 0.5-1.5wt% (specifically 1wt%) of formaldehyde scavenger, the drum is rotated and beaten for 40-80 minutes (specifically 60 minutes).

[0074] (7) After 6-12 hours, the following substances are added to the drum, based on the total weight of the cowhide: 0.5-1.5 wt% (specifically 1 wt%) of M303 ultra-large molecular acrylic acid and 2-4 wt% (specifically 3 wt%) of SA small molecular acrylic acid; the drum is rotated for 400-440 minutes (specifically 420 minutes); after the rotation, the cowhide is washed clean with water at room temperature, with a liquid retention ratio of 180-220 wt% (specifically 200 wt%), based on the total weight of the cowhide.

[0075] (8) Add the following substances into the drum, based on the total mass of the cowhide: 0.15-0.25 wt% (specifically 0.2 wt%) of EDTA chelating agent, 0.02-0.06 wt% (specifically 0.04 wt%) of preservative and 0.03-0.07 wt% (specifically 0.05 wt%) of baking soda. After the drum is rotated for 8-12 minutes (specifically 10 minutes), the pH value is tested and the drum is taken out.

[0076] The cowhide mat produced by this vegetable tanning process has a rich and elastic leather feel. Compared with the cowhide mats on the market (most of which are 3mm thick), the thickness of this cowhide mat can reach 5mm, and the feel is still soft and elastic, which is more fleshy and leathery than most cowhide mats on the market.

[0077] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0078] The above is only an embodiment of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. Pure vegetable tanning process of cowhide mat, characterized by: The process includes a soaking process, an alkali soaking process, a re-liming process, and a tanning process. The soaking process is used to restore the moisture of the cowhide and remove dirt. The alkali soaking process is used to separate the epidermis and dermis and loosen the collagen fibers. The re-liming process is a supplementary treatment process after the alkali soaking process to loosen the collagen fibers. The tanning process is used to combine the tanning agent with the collagen fibers. The tanning process includes a primary tanning process and a re-tanning process. The primary tanning process comprises the following steps: (1) Add the following substances to a container containing cowhide, based on the total weight of the cowhide: 120-180 wt% of room temperature water, 1.5-2.5 wt% of lime, 0.2-0.4 wt% of sodium sulfide, 0.2-0.4 wt% of sodium hydrosulfide, and 0.4-0.6 wt% of a liming agent; after 7-12 hours, wash the cowhide with running water; (2) placing the cowhide obtained in step (1) into a drum, and adding the following substances into the drum, based on the total mass of the cowhide: 0.5-1.5 wt% of a deliming agent, 0.2-0.4 wt% of a degreasing agent, 2-4 wt% of ammonium sulfate, and 0.4-0.6 wt% of a softening enzyme, and rotating the drum for 400-450 minutes; after the drum is rotated, washing the cowhide with water at room temperature; (3) placing the cowhide obtained in step (2) into a drum, and adding the following substances into the drum, based on the total mass of the cowhide: 5-7 wt% of salt, 5-7 wt% of sodium sulfate, 0.5-1.5 wt% of a fatliquor, and 1-2 wt% of sulfuric acid, and rotating the drum for 20-40 minutes; (4) Continue to add the following substances to the drum, based on the total weight of the cowhide: 0.1-0.3 wt% of acid protease, rotate the drum for 1.5-3 hours and beat for 7-12 hours; (5) Continue to add the following substances to the drum, based on the total weight of the cowhide: 3-5 wt% glutaraldehyde, and rotate the drum and beat for 200-400 minutes; (6) Continue to add the following substances to the drum, based on the total weight of the cowhide: 0.5-1.5 wt% of an alkali extracting agent and 1.5-2.5 wt% of baking soda, rotate the drum for 100-150 minutes and beat for 32-40 hours; (7) After 20-28 hours, wash with water after taking out the drum; The retanning process comprises the following steps: (1) Adding the primary tanned cowhide into a drum, and adding the following substances into the drum, based on the total mass of the cowhide: 120-180 wt% of room temperature water, 0.4-0.6 wt% of a fatliquor, 1-2 wt% of fish oil, 0.2-0.4 wt% of a complexing agent, and 1.3-1.7 wt% of dispersed tannins, and rotating the drum for 15-25 minutes; (2) adding the following substances to the drum three times, based on the total weight of the cowhide: 8-12 wt% of wattle bark extract, 4-6 wt% of saccharified quebracho tannin, 1-3 wt% of chestnut tannin, and 2-4 wt% of bayberry tannin; adding once a day, rotating the drum and beating for 40-80 minutes after each addition; after the last addition, rotating the drum and beating for 20-28 hours; (3) Wash the cowhide with water at room temperature, add 2-4 wt% hydrogen peroxide in a drum, and rotate the drum for 100-140 minutes; (4) Add the following substances to the drum, based on the total weight of the cowhide: 0.5-1.5 wt% oxalic acid, and rotate the drum for 60-120 minutes; (5) Washing the cowhide and heating it to 40-50°C. Add the following substances to the drum, based on the total weight of the cowhide: 1.5-2.5 wt% of animal purified protein, and rotate the drum for 15-25 minutes; (6) adding the following substances, based on the total weight of the cowhide, into a drum: 1.5-2.5 wt% neatsfoot oil, 6-8 wt% fish oil, 0.4-0.6 wt% vegetable oil, 1.5-2.5 wt% animal fat, 1.3-1.7 wt% fatliquor, 0.4-0.6 wt% dispersed tannin, 0.2-0.4 wt% complexing agent, 0.4-0.6 wt% baking soda, 0.0.5-0.07 wt% mildew inhibitor, and 0.5-1.5 wt% formaldehyde scavenger, and rotating the drum and beating for 40-80 minutes; (7) After 6-12 hours, the following substances are added to the drum, based on the total mass of the cowhide: 0.5-1.5 wt% of macromolecular acrylic acid and 2-4 wt% of micromolecular acrylic acid; the drum is rotated for 400-440 minutes; after the rotation, the cowhide is washed with room temperature water, with a liquid retention ratio of 180-220 wt%. (8) Add the following substances into the drum, based on the total weight of the cowhide: 0.15-0.25 wt% of a complexing agent, 0.02-0.06 wt% of a preservative, and 0.03-0.07 wt% of baking soda, and rotate the drum for 8-12 minutes before removing the drum.

2. The pure vegetable tanning process for cowhide mats according to claim 1, characterized in that: The immersion process includes a pre-immersion process and a main immersion process; The pre-soaking treatment comprises the following steps: (1) Put the cowhide into a drum, and add the following substances into the drum, based on the total mass of the cowhide: 250-350wt% of room temperature water, 0.2-0.4wt% of a fungicide, 0.05-0.15wt% of a soaking agent, and 0.2-0.4wt% of soda ash. The drum is rotated for 20-40 minutes and then stopped for 20-40 minutes, and repeated 4-6 times; wherein the fungicide is added twice, with an interval of 5-7 hours between the two times; (2) After 10-15 hours, pour out the hide and remove the flesh; The main immersion treatment includes: placing the cowhide into a rotary drum, and adding the following substances into the drum, based on the total mass of the cowhide: 150-250wt% of room temperature water, 0.1-0.2wt% of a fungicide, 0.1-0.3wt% of a immersion aid, 0.05-0.15wt% of a immersion agent, 0.1-0.3wt% of a degreasing agent and 0.3-0.7wt% of soda ash; rotating the drum and beating for 20-40 minutes, then stopping for 20-40 minutes, and repeating 1-3 times.

3. The pure vegetable tanning process for cowhide mats according to claim 1, characterized in that: The alkali leaching process comprises the following steps: (1) After 8-12 hours of soaking, the cowhide is washed and drained, leaving 2-4 wt% of water and placed in a drum. The following substances are added to the drum, based on the total weight of the cowhide: 0.1-0.3 wt% of liming enzyme, 0.4-0.6 wt% of liming auxiliary agent, and 0.4-0.6 wt% of sodium hydrosulfide. The drum is rotated for 20-40 minutes and then stopped for 30-50 minutes. (2) Add the following substances into the drum, based on the total weight of the cowhide: 0.4-0.6 wt% of sodium sulfide, 0.1-0.3 wt% of a degreasing agent, and 0.4-0.6 wt% of lime, and rotate the drum for 20-40 minutes and then stop for 30-50 minutes; (3) Add the following substances into the drum, based on the total weight of the cowhide: 0.5-1.5 wt% of sodium sulfide, 0.5-1.5 wt% of lime, and 0.05-0.15 wt% of a penetrant, and rotate and beat the cowhide for 15-25 minutes, then rest for 20-40 minutes, and repeat 2-4 times; (4) Add the following substances into the drum, based on the total weight of the cowhide: 0.5-1.5 wt% of lime, 0.15-0.25 wt% of a liming agent, rotate and beat the drum for 15-25 minutes, then rest for 20-40 minutes, and repeat 2-4 times; (5) Add the following substances into the drum, based on the total mass of the cowhide: 70-90wt% of room temperature water, 0.05-0.15wt% of a degreasing agent, 1-3wt% of lime, and 0.05-0.15wt% of a penetrant. The drum is rotated and beaten for 3-7 minutes, then stopped for 20-30 minutes before proceeding to the next step.

4. The pure vegetable tanning process for cowhide mats according to claim 1, characterized in that: The re-ashing process comprises the following steps: (1) Add the following substances into the drum, based on the total weight of the cowhide: 0.2-0.4 wt% of the swelling agent, rotate for 4-6 minutes, then stop for 20-30 minutes, and repeat 7-9 times; (2) Add the following substances into the drum, based on the total mass of the cowhide: 0.05-0.15 wt% of a degreasing agent, 0.1-0.3 wt% of a liming aid, 2-4 wt% of lime, and 100-140 wt% of water at room temperature. The drum is rotated for 2-4 minutes, stopped for 25-30 minutes, and beaten for 7-12 hours.

5. The pure vegetable tanning process for cowhide mats according to claim 3, characterized in that: In steps (3) and (4) of the alkali leaching process, it is necessary to detect the temperature inside the drum.

6. The pure vegetable tanning process for cowhide mats according to claim 1, characterized in that: The pH value needs to be tested before the drum is taken out.

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