A tanning process for all-vegetable tanned cowhide flooring

Abstract

This invention relates to the field of leather processing technology and discloses a tanning process for all-vegetable tanned cowhide floor leather, comprising the following steps: pre-treating raw hides followed by acid immersion pre-tanning, tanning, intermediate treatment, retanning, and post-treatment to obtain finished leather; a first pre-tanning agent is added during the acid immersion pre-tanning process; the tanning process includes the following steps: adding water and the first tanning agent to a groove and rotating; adding a second tanning agent and rotating; adding a third tanning agent and rotating; adding a fourth tanning agent and rotating; adding a fifth tanning agent and rotating; then transferring to a drum, adding water and a sixth tanning agent and rotating; adding a seventh tanning agent and rotating; the retanning process includes the addition of a first retanning agent and a second retanning agent. This invention uses a combination of groove immersion and drum tanning, which greatly shortens the tanning time, reduces the floor space required, and saves labor costs.

Description

Technical Field

[0001] This invention relates to the field of leather processing technology, and in particular to a tanning process for all-vegetable tanned cowhide floor leather. Background Technology

[0002] Currently, there are three main tanning processes for cowhide: chrome tanning, aldehyde tanning, and vegetable tanning. The first two types of tanning produce hides that are difficult to meet the requirements for flooring leather in terms of firmness, durability, and ease of shaping.

[0003] Floor coverings require good durability, wear resistance, and strong shape retention. Traditional chrome-tanned leather is soft and not pressure resistant. Semi-vegetable tanned leather is difficult to achieve the required thickness for floor coverings and has a relatively complex process. Vegetable tanning has unique advantages such as being strong and wear-resistant, highly malleable, and environmentally friendly. However, the current traditional vegetable tanning process uses the immersion method in tanning tanks, which has problems such as long production cycles and large investment in manpower and space.

[0004] The current tanning process for vegetable-tanned floor leather mainly uses the tanning bath immersion method. After the pickling process ends, the leather is soaked in the tanning bath. The tanning bath with a higher concentration is replaced periodically, and the concentration of tannin in the tanning bath is gradually increased. This process usually takes several months. This is mainly because the tannin in the tanning liquor exists mainly in the form of colloidal particles. The penetration rate into the leather is very slow, but the binding rate with the leather collagen is relatively fast. Therefore, a lot of time is needed to ensure that the tanning particles penetrate into the leather, so as to obtain dense, firm, full and strong vegetable-tanned leather.

[0005] Therefore, there is an urgent need for a tanning process for all-vegetable tanned cowhide flooring to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned shortcomings and design a floor leather rapid tanning system that combines grooving and drum operation. This system has a short tanning cycle time, requires little space, low human resource input, and allows for the recycling of tanning liquor. It is an environmentally friendly, economical, and efficient floor leather tanning process system.

[0007] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0008] A tanning process for all-vegetable tanned cowhide floor leather includes the following steps: pre-treating the raw hide, followed by acid immersion pre-tanning, tanning, intermediate treatment, retanning, and post-treatment to obtain the finished leather;

[0009] A first pretanning agent is added during the pickling and pretanning process;

[0010] The tanning process includes the following steps: adding water and a first tanning agent to a trough and rotating; adding a second tanning agent and rotating; adding a third tanning agent and rotating; adding a fourth tanning agent and rotating; adding a fifth tanning agent and rotating;

[0011] Then it is transferred to a rotating drum, where water and the sixth tanning agent are added and the drum is rotated; the seventh tanning agent is added and the drum is rotated.

[0012] The retanning process includes the addition of a first retanning agent and a second retanning agent.

[0013] Preferably, the first pretanning material comprises 3% non-expanding acid, 2% aldehyde tanning agent, and 4% naphthalene synthetic tanning agent;

[0014] Alternatively, the first pretanning material may include 3% non-expanding acid, 4% aromatic sulfonic acid synthetic tanning agent, and 4% tannin from Vitex negundo bark.

[0015] Furthermore: the first pretanning material comprises 3% non-expanding acid SINTERAL PL6, 2% aldehyde tanning agent TRUPOTAN OXB, and 4% naphthalene-based synthetic tanning agent LECOSIN PS;

[0016] Alternatively, the first pretanning material may include 3% non-expanding acid SINTERAL PL6, 4% aromatic sulfonic acid synthetic tanning agent TANIGAN CHN, and 4% chamomile bark tannin WEIBULL LIGHT.

[0017] Specifically, the pickling and pretanning process includes the following steps:

[0018] Acid immersion: Temperature 20℃, liquid ratio 60%, add 10% sodium chloride, 0.2% EDTA, adjust Baumé degree to 8-10, add 3% SINTERAL PL6 (ALPA) and rotate for 60 minutes, add 0.2% formic acid and rotate for 30 minutes, add 0.2% sulfuric acid and rotate for 45 minutes, add 0.1% sulfuric acid and rotate for 300 minutes, switch to automatic mode (rotate for 5 minutes and stop for 55 minutes), run in automatic mode for 12 hours, pH: 3.0-3.2, bromocresol green test shows the cut is completely yellow;

[0019] Pretanning: Add 1% TRUPOTAN OXB (TRUMPLER) and rotate for 30 minutes, then add 1% TRUPOTAN OXB (TRUMPLER) and rotate for 120 minutes, then add 4% LECOSIN PS (FGL) and rotate for 240 minutes. Set to automatic mode (rotate for 5 minutes and stop for 55 minutes) and run in automatic mode for 12 hours.

[0020] Alternatively, specifically, the pickling and pretanning process includes the following steps:

[0021] Pickling-Pretanning: Temperature 20℃, liquor ratio 60%, add 8% sodium sulfate, 0.2% EDTA, adjust Baumé degree to 8-10, add 3% SINTERAL PL6 (ALPA) and rotate for 120 minutes, add 0.2% formic acid and rotate for 60 minutes, add 4% TANIGAN CHN (LANXESS) and rotate for 300 minutes, switch to automatic mode (rotate for 5 minutes and stop for 55 minutes), run in automatic mode for 12 hours, add 4% WEIBULL LIGHT (TANAC) and rotate for 120 minutes.

[0022] Preferably, the first tanning agent comprises 1% sodium bisulfite, 2% naphthalene-based synthetic tanning agent, 2% sodium formate, 15% tannin from vitex bark, and 10% tannin from hardwood.

[0023] The second tanning agent includes 12% saccharified chestnut tannin, 1% sodium bisulfite, 6% vitex bark tannin, 6% hardwood tannin, 1% naphthalene-based synthetic tanning agent, and 1% sulfite-treated fish oil;

[0024] The third tanning agent includes 0.5% oxalic acid, 5% sulfone-based alternative synthetic tanning agent, 10% chestnut tannin, 1% naphthalene-based synthetic tanning agent, and 1% sulfite-treated fish oil;

[0025] The fourth tanning agent includes 12% saccharified chestnut tannin, 12% chestnut tannin, 0.5% EDTA, and 1% sodium bisulfite;

[0026] The fifth tanning agent includes 0.3% sodium bisulfite and 0.5% oxalic acid;

[0027] Alternatively, the first tanning agent may include 4% sodium chloride and 1% soda ash;

[0028] The second tanning agent includes 1% sodium bisulfite, 25% tannin from vitex bark, 10% tannin from hardwood, and 2% naphthalene-based synthetic tanning agent;

[0029] The third tanning agent includes 0.5% anti-snagging agent, 25% saccharified chestnut tannin, 10% vitex bark tannin, 10% hardwood tannin, 2% naphthalene synthetic tanning agent, 1% sodium bisulfite, 1% sulfite whale oil, and 0.5% antifungal agent.

[0030] The fourth tanning agent includes 5% sulfone-based alternative synthetic tanning agent, 10% saccharified chestnut tannin, 1% naphthalene-based synthetic tanning agent, 1% sulfite-treated fish oil, 3% liming aid, and 1% oxalic acid;

[0031] The fifth tanning agent includes 0.3% sodium bisulfite;

[0032] The sixth tanning agent includes 10% chestnut tannin, 5% sulfone-based synthetic tanning agent, 5% hardwood tannin, 0.5% mineral oil, and 0.5% anti-snagging agent;

[0033] The seventh tanning agent comprises 0.5% mold inhibitor, 50% water, 0.5% oxalic acid, 0.5% sodium bisulfite, and 0.2% EDTA.

[0034] Furthermore: the first tanning agent comprises 1% sodium bisulfite, 2% naphthalene-based synthetic tanning agent LECOSIN PS, 2% sodium formate, 15% wicker bark tannin WEIBULL LIGHT, and 10% hardwood tannin TTO.

[0035] The second tanning agent includes 12% saccharified chestnut tannin (TCR), 1% sodium bisulfite, 6% vitex bark tannin (WEIBULL LIGHT), 6% scleroderma tannin (TTO), 1% naphthalene-based synthetic tanning agent (LECOSIN PS), and 1% sulfite-treated fish oil (TRUPONOL FSF).

[0036] The third tanning agent includes 0.5% oxalic acid, 5% sulfone-substituted synthetic tanning agent BLANCOTAN BC, 10% chestnut tannin CHESTNUT, 1% naphthalene-based synthetic tanning agent LECOSIN PS, and 1% sulfite-treated fish oil TRUPONOL FSF.

[0037] The fourth tanning agent includes 12% saccharified chestnut tannin (TCR), 12% chestnut tannin (CHESTNUT), 0.5% EDTA, and 1% sodium bisulfite;

[0038] The fifth tanning agent includes 0.3% sodium bisulfite and 0.5% oxalic acid;

[0039] Alternatively, the first tanning agent may include 4% sodium chloride and 1% soda ash;

[0040] The second tanning agent includes 1% sodium bisulfite, 25% WEIBULL LIGHT bark tannin, 10% TTO bark tannin, and 2% LACOSIN PS tannin.

[0041] The third tanning agent includes 0.5% anti-snagging agent ERHA GM 3995, 25% saccharified chestnut tannin TCR, 10% vitex bark tannin WEIBULL LIGHT, 10% hardwood tannin TTO, 2% naphthalene-based synthetic tanning agent LECOSIN PS, 1% sodium bisulfite, 1% sulfite-treated whale oil IDROSOL S, and 0.5% mildew inhibitor BK55;

[0042] The fourth tanning agent includes 5% sulfone-substituted synthetic tanning agent BLANCOTAN BC, 10% saccharified chestnut tannin TCR, 1% naphthalene-based synthetic tanning agent LECOSIN PS, 1% sulfite-treated fish oil TRUPONOL FSF, 3% liming aid BIOSINT CG, and 1% oxalic acid.

[0043] The fifth tanning agent includes 0.3% sodium bisulfite;

[0044] The sixth tanning agent includes 10% chestnut tannin, 5% sulfone-substituted synthetic tanning agent BLANCOTAN BC, 5% hardwood tannin TTO, 0.5% mineral oil IDROSIN ME, and 0.5% anti-snagging agent ERHA GM 3995.

[0045] The seventh tanning agent comprises 0.5% mold inhibitor BK55, 50% water, 0.5% oxalic acid, 0.5% sodium bisulfite, and 0.2% EDTA.

[0046] Preferably, during the tanning process, after tanning in the trough is completed, the tanning liquor in the trough is recovered as recycled trough old tanning liquor; during the tanning process, after tanning in the drum is completed, the tanning liquor in the drum is recovered as recycled drum old tanning liquor. The retained recycled trough old tanning liquor and recycled drum old tanning liquor can be used in the next production process. Similarly, the recycled trough old tanning liquor and recycled drum old tanning liquor used in this production are retained from the previous batch of production.

[0047] Preferably, the trough also contains a circulating old tanning liquor; the total mass of the water and the circulating old tanning liquor is 90-98% of the trough capacity. Here, the trough capacity, the amount of water added, and the amount of circulating old tanning liquor added are all measured by mass.

[0048] Specifically, if there is no existing recycled tanning liquor, 1.5T of water at 20°C, 15% WEIBULL LIGHT, 10% TTO (tungsten tannin), and 1% soda ash can be added as substitutes.

[0049] Alternatively, you can add 10T of water at 20°C, along with 30% WEIBULL LIGHT, 20% TTO (Toluene Tate), and 0.5% sodium bisulfite as a substitute.

[0050] Preferably, the seventh tanning agent also includes 50% recycled drum tanning liquor.

[0051] Specifically, if there is no existing recycled tanning liquor from the drum, 50% water at 35°C, 2% CHESTNUT (SILVATEAM), 1% BLANCOTAN BC (SILVATEAM), and 1% TTO (Tingjiang New Materials) can be added as substitutes.

[0052] Specifically, the tanning process includes the following steps:

[0053] Tanning: Use a 15T (ton) tanning vat, add 13T (tons) of 20℃ water, 1500KG of circulating old tanning liquor, 1% sodium bisulfite, 2% LECOSIN PS (FGL), 2% sodium formate, 15% WEIBULL LIGHT (TANAC), 10% TTO (Tingjiang New Materials), and 4% sodium chloride. Adjust the Baumé degree to 4.0 and pH to 4.0. Add the hides and set the automatic mode (rotate for 30 minutes, stop for 30 minutes). Run the automatic mode for 12 hours, adjusting the temperature to 25℃. Add 12% saccharified chestnut tannin TCR (Tingjiang New Materials), 1% sodium bisulfite, 6% WEIBULL LIGHT (TANAC), 6% TTO (Tingjiang New Materials), 1% LECOSIN PS (FGL), and 1% TRUPONOL. FSF (TRUMPLER), adjust Baumé degree to 6.0, run for 360 minutes, switch to automatic mode (run for 30 minutes, stop for 30 minutes), run in automatic mode for 12 hours, add 0.5% oxalic acid, 5% BLANCOTAN BC (SILVATEAM), 10% CHESTNUT (SILVATEAM), 1% LECOSIN PS (FGL), 1% TRUPONOL FSF (TRUMPLER), adjust Baumé degree to 7.0, rotate for 180 minutes, adjust temperature to 30℃, add 12% saccharified chestnut tannin TCR (Tingjiang New Material), 12% CHESTNUT (SILVATEAM), 0.5% EDTA, 1% sodium bisulfite, adjust Baumé degree to 8.0-9.0, rotate for 360 minutes, then switch to automatic mode (rotate for 30 minutes and stop for 30 minutes), run in automatic mode for 12 hours, add 0.3% sodium bisulfite, rotate for 60 minutes, add 0.5% oxalic acid, rotate for 60 minutes, peel, collect the tanning liquor from this process as recycled old tanning liquor for tanning.

[0054] Rotary drum tanning: temperature 30℃, 30% water, 10% CHESTNUT (SILVATEAM), 5% BLANCOTAN BC (SILVATEAM), 5% TTO (Tingjiang New Materials), 0.5% IDROSIN ME (FGL), 0.5% ERHA GM 3995. Rotate for 12 hours, then switch to automatic mode (rotate for 10 minutes, stop for 50 minutes), run in automatic mode for 12 hours, add 0.5% BK55 (Bauska), rotate for 4 hours, add 50% water and raise the temperature to 35℃, add 50% of the circulating drum old tanning liquor, 0.5% oxalic acid, 0.5% sodium bisulfite, 0.2% EDTA, rotate for 60 minutes, remove from drum and set up. Collect the tanning liquor from this process as the circulating drum old tanning liquor.

[0055] Alternatively, specifically, the tanning process includes the following steps:

[0056] Tanning: Use a 15T (ton) tanning vat, add 4T of 20℃ water, 10T of circulating old tanning liquor, 4% sodium chloride, and 1% soda ash. Adjust the Baumé degree to 4.0 and the pH to 4.5-4.8. Add the hides and set the automatic mode (30 minutes forward rotation, 30 minutes reverse rotation) for 12 hours. Adjust the temperature to 25℃, add 1% sodium bisulfite, 25% WEIBULL LIGHT (TANAC), 10% TTO (Tingjiang New Materials), and 2% LECOSIN PS (FGL). Check the Baumé degree to 6.0-6.5 and the pH to 4.6-4.8. Set the automatic mode (30 minutes of rotation, 30 minutes of stop) for 12 hours. Add 0.5% ERHA GM3995 (TFL), 25% TCR (Tingjiang New Materials), and 10% WEIBULL... LIGHT (TANAC), 10% TTO (Tingjiang New Materials), 2% LECOSIN PS (FGL), 1% Sodium Bisulfite, 1% IDROSOL S (FGL), 0.5% BK55 (Bauska). Set to automatic mode (run for 30 minutes, stop for 30 minutes). Run in automatic mode for 12 hours. Check Baume degree: 8.5-9.0, pH: 4.6-4.8. Add 5% BLANCOTAN BC (SILVATEAM), 10% TCR (Tingjiang New Materials), 1% LECOSIN PS (FGL), 1% TRUPONOL FSF (TRUMPLER), 3% BIOSINT. CG (BIOKIMICA), 1% oxalic acid, set to automatic mode (run for 30 minutes, stop for 30 minutes), run in automatic mode for 12 hours, check Baumé degree: 9.0-9.5, pH: 4.0-4.2, add 0.3% sodium bisulfite, set to automatic mode (run for 30 minutes, stop for 30 minutes), run in automatic mode for 12 hours, check Baumé degree: 9.0-9.5, pH: 4.0-4.2, peel off, collect the tanning liquor from this process as recycled old tanning liquor for tanning tanks;

[0057] Rotary drum tanning: temperature 30℃, 30% water, 10% CHESTNUT (SILVATEAM), 5% BLANCOTAN BC (SILVATEAM), 5% TTO (Tingjiang New Materials), 0.5% IDROSIN ME (FGL), 0.5% ERHA GM 3995. Rotate for 12 hours, then switch to automatic mode (rotate for 10 minutes, stop for 50 minutes), run in automatic mode for 12 hours, add 0.5% BK55 (Bauska), rotate for 4 hours, add 50% water and raise the temperature to 35℃, add 50% of the circulating drum old tanning liquor, 0.5% oxalic acid, 0.5% sodium bisulfite, 0.2% EDTA, rotate for 60 minutes, remove from drum and set up. Collect the tanning liquor from this process as the circulating drum old tanning liquor.

[0058] Preferably, the first retanning agent comprises 6% phenolic tanning agent, 2% melamine resin tanning agent, 2% chestnut tannin, 3% sulfone-based alternative synthetic tanning agent, 2% filler resin, 2% sulfite whale oil, and 1% honey.

[0059] The second retanning agent includes 2% highly astringent sulfone synthetic tanning agent.

[0060] Furthermore: the first retanning agent comprises 6% phenolic tanning agent BASYNTAN DLE, 2% melamine resin tanning agent BIOPLEN FFR, 2% chestnut tannin CHESTNUT, 3% sulfone-substituted synthetic tanning agent BLANCOTAN BC, 2% filler resin BIOPLEN MB, 2% sulfite-treated whale oil IDROSOL S, and 1% honey;

[0061] The second retanning agent includes 2% of the highly astringent sulfone synthetic tanning agent SELLATAN LV.

[0062] Specifically, the retanning process includes the following steps:

[0063] Retanning: Temperature 35℃, liquor ratio 10%, rotation for 60 minutes, 1% magnesium sulfate, rotation for 60 minutes, 6% BASYNTANDLE (BASF), 2% BIOPLEN FFR, 2% CHESTNUT

[0064] (SILVATEAM), 3% BLANCOTAN BC (SILVATEAM), 2% BIOPLEN MB (BIOKIMICA), 60 minutes; 2% IDROSOL S (FGL), 1% honey, 60 minutes; 0.5% oxalic acid, 30 minutes; 2% SELLATANLV (TFL), 60 minutes, then remove from drum.

[0065] Preferably, the pretreatment includes raw hide batching, raw hide cutting, soaking in water, soaking in ash, removing flesh from ash-soaked hides, and deashing and softening.

[0066] The intermediate processing includes resting on a flat surface, squeezing out water, slicing, and evenly shaving.

[0067] The post-processing includes stretching, dewatering, heat stretching, hanging drying, vibrating softening, rolling, and warehousing.

[0068] Preferably, the immersion includes the following steps:

[0069] Pre-soaking: Add water, wetting and dispersing agent, soda ash, rotate and drain;

[0070] Main soaking: Add wetting and dispersing aids, soda ash, and sodium sulfide, rotate and drain; add salt, adjust Baumé degree to 4-4.5, rotate; add bactericide, wetting and dispersing aids, degreasing agent, soaking pH stabilizer, and soaking ash aid, rotate and remove meat from drum.

[0071] Furthermore: the wetting and dispersing agent is BORRON A, the bactericide is DIX-005, the degreasing agent is BORRON SE, the soaking water pH stabilizer is PELLVIT MN-A, and the liming agent is ERHAVIT SP.

[0072] Specifically, the immersion includes the following steps:

[0073] Pre-soaking water: Pre-soaking water temperature 18-22℃, liquor ratio 150%, 0.2% BORRON A (TFL), 0.2% soda ash, rotate for 60 minutes, drain;

[0074] Main soaking: Control internal temperature 22-24℃, liquid ratio 150%, 0.1% BORRON A (TFL), 0.2% soda ash, 0.1% sodium sulfide, run for 60 minutes, drain, liquid ratio 150%, internal temperature 22-24℃, add 7% sodium chloride, adjust Baume degree: 4-4.5, switch to automatic mode and run for 3 minutes, stop for 27 minutes, repeat 4 times, add 0.25% DIX-005 (Borska), 0.1% BORRON A (TFL), 0.2% BORRON SE (TFL), 0.15% PELLVIT MN-A (TFL), 0.5% ERHAVIT SP (TFL), run for 90 minutes, then switch to automatic mode (run for 5 minutes, stop for 25 minutes, repeat 10 times), then run for 480 minutes, remove from drum and remove meat.

[0075] Preferably, the impregnation includes the following steps: adding degreasing agent, lime powder, impregnation aid, and enzyme-containing impregnation aid, and rotating; adding sodium hydrosulfide, sodium sulfide, lime, anti-snagging agent, glucose, and impregnation aid and rotating; adding water, anti-snagging agent, wetting and dispersing aid, and sodium sulfide, and rotating before exiting the drum.

[0076] Furthermore: the degreasing agent is BORRON SE, the liming aid is one of ERHAVIT HS2 and BIOSINT CG, the enzyme-containing liming aid is Erhavit DMC, the anti-snagging agent is ERHA GM3034, and the wetting and dispersing aid is BORRON A.

[0077] Specifically, the impregnation process includes the following steps:

[0078] Lime impregnation: At room temperature and a liquid ratio of 0%, add 0.2% BORRON SE (TFL), 0.6% lime powder, 2.2% ERHAVITHS2 (TFL), and 0.2% Erhavit DMC (TFL). Rotate for 30 minutes, stop for 15 minutes, rotate for 30 minutes, add 1.5% sodium hydrosulfide, 3% sodium sulfide, 4.5% lime, 0.3% ERHA GM3034 (TFL), 1% glucose, and 0.5% BIOSINT CG (BIOKIMICA). Rotate for 60 minutes, check for shedding, switch to automatic mode (rotate for 5 minutes, stop for 55 minutes, for a total of 20 times), add 60% warm water, control the internal temperature at 26-27℃, add 0.3% ERHA GM3034 (TFL), 0.1% BORRON A (TFL), and 1% sodium sulfide, rotate for 330 minutes, and remove from the drum.

[0079] Preferably, the deashing and softening process includes the following steps: adding water and ammonium sulfate, rotating and draining; adding water, ammonium sulfate, deashing agent, and sodium bisulfite, rotating; adding ammonium sulfate, deashing agent, sodium bisulfite, and glucose, rotating; adding emulsifier and softening enzyme, rotating and draining, and washing with water.

[0080] Furthermore: the deashing agent is DERMASCAL ASB, the emulsifier is BORRON SAF, and the softening enzyme is OROPON OO.

[0081] Specifically, the deashing and softening process includes the following steps:

[0082] Deashing and softening: Pre-deashing temperature 30℃, liquid ratio 150%, 0.3% ammonium sulfate, rotate for 30 minutes, then switch to automatic mode (rotate for 5 minutes, stop for 55 minutes), and drain in automatic mode for 12 hours; Main deashing and softening temperature 35℃, liquid ratio 50%, 0.7% ammonium sulfate, 1% DERMASCAL ASB (TFL), 0.5% sodium bisulfite, rotate for 30 minutes, then add 0.5% ammonium sulfate, 1% DERMASCAL ASB (TFL), 0.5% sodium bisulfite, and 0.5% glucose, rotate for 90 minutes, check deashing status (pH: 7.0, cut fully transparent), add 0.1% BORRON SAF (TFL) and 0.5% OROPON OO (TFL), rotate for 25 minutes, check softening status, drain, and wash twice with water.

[0083] Alternatively, preferably, the deashing and softening process includes the following steps: adding water and ammonium sulfate, rotating and then draining; adding water, ammonium sulfate, deashing agent, sodium bisulfite, and emulsifier and rotating; adding ammonium sulfate, sodium bisulfite, and glucose, rotating and then draining, followed by washing with water.

[0084] More specifically: the deashing agent is DERMASCAL ASB, and the emulsifier is BORRON SAF.

[0085] Specifically, the deashing and softening process includes the following steps:

[0086] Deashing and softening: Pre-deashing temperature 30℃, liquid ratio 150%, 0.3% ammonium sulfate, rotate for 30 minutes, then switch to automatic mode (rotate for 5 minutes, stop for 55 minutes), and run in automatic mode for 12 hours; Main deashing and softening temperature 35℃, liquid ratio 50%, 0.7% ammonium sulfate, 1% DERMASCAL ASB (TFL), 0.5% sodium bisulfite, 0.2% BORRON SAF (TFL), rotate for 30 minutes, add 0.5% ammonium sulfate, 0.5% sodium bisulfite, and 0.5% glucose, rotate for 90 minutes, check the deashing status: pH: 7.0, cut fully transparent, drain and wash twice.

[0087] Preferably, the hanging drying process includes the following steps: Day 1: Temperature 20℃, Humidity 80-85%; Day 2: Temperature 25℃, Humidity 60-65%; Day 3: Temperature 30℃, Humidity 50%.

[0088] The working principle of this invention:

[0089] The present invention aims to develop a rapid tanning process that combines grooving and drum rotation, which shortens the production cycle from the traditional several months to a year to one and a half months. The process is highly automated, requires less manpower, occupies less equipment space, makes reasonable use of space, recycles tanning liquor, basically achieves zero emissions, and saves more than 30% in production costs.

[0090] This invention employs a tanning method combining grooving and rotating drums. The entire tanning process is divided into two stages. The pre-tanned leather undergoes primary tanning in the grooving. First, low-absorptive-stretching WEIBULL LIGHT and TTO (tung oil tannin) are added to further fix the fibers and maintain inter-fiber gaps. Sodium bisulfite is added to increase the tannin penetration rate. Sulfone-based synthetic tanning agent BLANCOTAN BC and highly astringent saccharified chestnut tannin TCR and CHESTNUT are added to make the leather firm and heavy. The rotation of the grooving provides strong mechanical action and suitable temperature, accelerating the movement of tannin particles and thus increasing the penetration rate of tannin particles into the leather. This process takes approximately 7 days, thus shortening the tanning cycle. During the retanning process, BASYNTAN DLE (white tannin) and BIOPLEN FFR (melamine) are added to the rotating drum to improve the leather color. Chestnut tannin, BIOPLEN MB (filling resin), and SELLATAN (sulfone-based synthetic tanning agent) are also added. LV enhances the filling by adding magnesium sulfate to further fix free tannins, reducing migration and the formation of stains. Sulfated fish oil Idrosol S and honey are added to increase lubrication and moisturization, reducing cracking during machining and drying. Finally, oxalic acid is used to clean the grain and flesh surfaces to remove excess unbound tannins, resulting in a uniform color of the tanned leather and reducing the risk of contamination, drying oxidation stains, and cracking.

[0091] This invention incorporates the aldehyde tanning agent TRUPOTAN OXB or the aromatic sulfonic acid synthetic tanning agent TANIGAN CHN and weibill light from vitex bark tannin during pre-tanning, enabling preliminary fiber shaping. During deliming, thorough deliming is required; the cut surface must be inspected and tested with phenolphthalein to ensure it remains colorless.

[0092] The present invention has the following requirements in the screening and application of vegetable tannins:

[0093] ① Add the fast-penetrating agent first, followed by the one with strong binding and good filling; add tannin in stages and gradually, adding the appropriate amount of tannin according to product requirements;

[0094] ② When applying vegetable tannins, first add the weak astringent WEIBULL LIGHT (TANAC) and hardwood tannin TTO (Tingjiang New Materials), and then add the strong astringent saccharified chestnut tannin TCR and chestnut tannin CHESTNUT (SILVATEAM). If too much strong astringent tannin is added at once, it can easily cause the leather to shrink significantly, thicken significantly, and wrinkle significantly.

[0095] The hanging drying process of this invention (Day 1: Temperature 20℃, Humidity 80-85%; Day 2: Temperature 25℃, Humidity 60-65%; Day 3: Temperature 30℃, Humidity 50%) is essentially a drying process. In this invention, the drying operation has a significant impact on the quality of the finished leather. Tannin bonding is a slow process. There are a large number of unbonded tannins in the wet leather after drumming. These tannins will move towards the grain surface with the movement of water molecules, causing over-tanning of the grain surface and posing a risk of cracking. Therefore, the drying process must be slow and carefully controlled. The drying process is carried out in a closed room, with the starting temperature controlled at 20℃ and the starting humidity at 80-85%, and the ending temperature controlled at 30℃ and the humidity at 50%. The drying process usually takes 3 days.

[0096] The rolling process of this invention is carried out on a roller press. Through rolling, the resulting leather has a firm body, smooth grain, and improved abrasion resistance, tensile strength, and gloss.

[0097] Beneficial effects:

[0098] Traditional floor covering tanning is carried out in a tank, which is time-consuming, requires a large area, and is labor-intensive. This invention adopts a combination of grooving and rotating drums, which greatly shortens the tanning time, reduces the floor space, and saves labor costs. Detailed Implementation

[0099] The present invention will be further described below with reference to specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0100] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0101] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses industrial-grade pure or conventionally pure materials used in the leather preparation field.

[0102] All raw materials of this invention are conventional in the field, and each brand name and abbreviation is clear and distinct in its relevant application. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand name, abbreviation and corresponding application.

[0103] The molasses involved in this invention, also known as molasses or syrup, is mainly composed of sucrose, glucose, and fructose. It is a commonly used raw material in the field, and those skilled in the art are aware of its sources and methods of obtaining it.

[0104] All processes in this invention are referred to by abbreviations that are common abbreviations in the field. Each abbreviation is clear and specific in its relevant application area, and those skilled in the art can understand its conventional process steps based on the abbreviation.

[0105] The Baumé degree used in this invention is Baumé degree °Bé.

[0106] In this invention and its embodiments, the liquid ratios involved in each step, as well as the percentages of each chemical used, are all based on the mass of the hide being processed in the process, and are calculated as a percentage of the hide mass.

[0107] The categories, names, and manufacturers of the chemicals involved in the following examples are detailed in the table below:

[0108]

[0109]

[0110] Example 1

[0111] A tanning process for fully vegetable-tanned cowhide flooring includes the following steps:

[0112] 1. Raw hide batching

[0113] 2. Rawhide cutting: Starting from the tail, cut along the midrib for 130cm in length and 140cm in width perpendicular to the midrib. Butt is used for heavy leather tanning, and Shoulder is used for light leather products.

[0114] 3. Pre-soaking: Pre-soaking water temperature 18-22℃, liquor ratio 150%, 0.2% BORRON A (TFL), 0.2% soda ash, run for 60 minutes, drain; Main soaking: Control internal temperature 22-24℃, liquor ratio 150%, 0.1% BORRON A (TFL), 0.2% soda ash, 0.1% sodium sulfide, run for 60 minutes, drain, liquor ratio 150%, internal temperature 22-24℃, add 7% sodium chloride, adjust Baumé degree to 4-4.5, switch to automatic mode and run for 3 minutes, stop for 27 minutes, repeat 4 times, add 0.25% DIX-005 (Borska), 0.1% BORRON A (TFL), 0.2% BORRON SE (TFL), 0.15% PELLVIT MN-A (TFL), 0.5% ERHAVIT SP(TFL), after running for 90 minutes, switch to automatic mode (run for 5 minutes, stop for 25 minutes, for a total of 10 times), then run for 480 minutes, remove the meat from the drum;

[0115] 4. Lime Impregnation: At room temperature and a liquid ratio of 0%, add 0.2% BORRON SE (TFL), 0.6% lime powder, 2.2% ERHAVITHS2 (TFL), and 0.2% Erhavit DMC (TFL). Rotate for 30 minutes, stop for 15 minutes, rotate for 30 minutes, add 1.5% sodium hydrosulfide, 3% sodium sulfide, 4.5% lime, 0.3% ERHA GM3034 (TFL), 1% glucose, and 0.5% BIOSINT CG (BIOKIMICA). Rotate for 60 minutes, check for shedding, switch to automatic mode (rotate for 5 minutes, stop for 55 minutes, repeat 20 times), add 60% warm water, control the internal temperature at 26-27℃, add 0.3% ERHA GM3034 (TFL), 0.1% BORRON A (TFL), and 1% sodium sulfide, rotate for 330 minutes, and remove from the drum.

[0116] 5. Remove the flesh from the gray skin;

[0117] 6. Deashing and softening: Pre-deashing temperature 30℃, liquid ratio 150%, 0.3% ammonium sulfate, rotate for 30 minutes, then switch to automatic mode (rotate for 5 minutes, stop for 55 minutes), and drain in automatic mode for 12 hours; Main deashing and softening temperature 35℃, liquid ratio 50%, 0.7% ammonium sulfate, 1% DERMASCAL ASB (TFL), 0.5% sodium bisulfite, rotate for 30 minutes, then add 0.5% ammonium sulfate, 1% DERMASCAL ASB (TFL), 0.5% sodium bisulfite, and 0.5% glucose, rotate for 90 minutes, check the deashing status (pH: 7.0, cut fully transparent), add 0.1% BORRON SAF (TFL) and 0.5% OROPON OO (TFL), rotate for 25 minutes, check the softening status, drain, and wash twice with water;

[0118] 7. Acid Immersion: Temperature 20℃, liquid ratio 60%, add 10% sodium chloride, 0.2% EDTA, adjust Baumé degree to 8-10, add 3% SINTERAL PL6 (ALPA) and rotate for 60 minutes, add 0.2% formic acid and rotate for 30 minutes, add 0.2% sulfuric acid and rotate for 45 minutes, add 0.1% sulfuric acid and rotate for 300 minutes, switch to automatic mode (rotate for 5 minutes and stop for 55 minutes), run in automatic mode for 12 hours, pH: 3.0-3.2, bromocresol green test shows the cut is completely yellow;

[0119] 8. Pre-tanning: Add 1% TRUPOTAN OXB (TRUMPLER) and rotate for 30 minutes, add 1% TRUPOTAN OXB (TRUMPLER) and rotate for 120 minutes, add 4% LECOSIN PS (FGL) and rotate for 240 minutes, then switch to automatic mode (rotate for 5 minutes and stop for 55 minutes) and run in automatic mode for 12 hours.

[0120] 9. Tanning: Use a 15T (ton) tanning vat, add 13T (tons) of 20℃ water, 1500KG of circulating old tanning liquor, 1% sodium bisulfite, 2% LECOSIN PS (FGL), 2% sodium formate, 15% WEIBULL LIGHT (TANAC), 10% TTO (Tingjiang New Materials), and 4% sodium chloride. Adjust the Baumé degree to 4.0 and pH to 4.0. Add the hides and set the automatic mode (rotate for 30 minutes, stop for 30 minutes). Run the automatic mode for 12 hours, adjusting the temperature to 25℃. Add 12% saccharified chestnut tannin TCR (Tingjiang New Materials), 1% sodium bisulfite, 6% WEIBULL LIGHT (TANAC), 6% TTO (Tingjiang New Materials), 1% LECOSIN PS (FGL), and 1% TRUPONOL. FSF (TRUMPLER), adjust Baumé degree to 6.0, run for 360 minutes, switch to automatic mode (run for 30 minutes, stop for 30 minutes), run in automatic mode for 12 hours, add 0.5% oxalic acid, 5% BLANCOTAN BC (SILVATEAM), 10% CHESTNUT (SILVATEAM), 1% LECOSIN PS (FGL), 1% TRUPONOL FSF (TRUMPLER), adjust Baumé degree to 7.0, rotate for 180 minutes, adjust temperature to 30℃, add 12% saccharified chestnut tannin TCR (Tingjiang New Material), 12% CHESTNUT (SILVATEAM), 0.5% EDTA, 1% sodium bisulfite, adjust Baumé degree to 8.0-9.0, rotate for 360 minutes, then switch to automatic mode (rotate for 30 minutes and stop for 30 minutes), run in automatic mode for 12 hours, add 0.3% sodium bisulfite, rotate for 60 minutes, add 0.5% oxalic acid, rotate for 60 minutes, peel, collect the tanning liquor from this process as recycled old tanning liquor for tanning.

[0121] If there is no remaining recycled tanning liquor in the above process, 1.5T of water at 20℃, 15% WEIBULL LIGHT, 10% TTO tannin, and 1% soda ash can be added as substitutes.

[0122] Rotary drum tanning: temperature 30℃, 30% water, 10% CHESTNUT (SILVATEAM), 5% BLANCOTAN BC (SILVATEAM), 5% TTO (Tingjiang New Materials), 0.5% IDROSIN ME (FGL), 0.5% ERHA GM 3995. Rotate for 12 hours, then switch to automatic mode (rotate for 10 minutes, stop for 50 minutes), run in automatic mode for 12 hours, add 0.5% BK55 (Bauska), rotate for 4 hours, add 50% water and raise the temperature to 35℃, add 50% of the circulating drum old tanning liquor, 0.5% oxalic acid, 0.5% sodium bisulfite, 0.2% EDTA, rotate for 60 minutes, remove from drum and set up. Collect the tanning liquor from this process as the circulating drum old tanning liquor.

[0123] If there is no remaining recycled tanning liquor from the drum during the above process, 50% 35℃ water, 2% CHESTNUT (SILVATEAM), 1% BLANCOTAN BC (SILVATEAM), and 1% TTO (Tingjiang New Materials) can be added as substitutes.

[0124] 10. Let it stand for one week;

[0125] 11. Dewatering: Through-type dewatering;

[0126] 12. Cutting: Cut straight along the central ridge;

[0127] 13. Evenly cut: Cut to a thickness of 5.0 mm;

[0128] 14. Retanning: Temperature 35℃, liquor ratio 10%, rotating for 60 minutes, 1% magnesium sulfate, rotating for 60 minutes, 6% BASYNTANDLE (BASF), 2% BIOPLEN FFR, 2% CHESTNUT

[0129] (SILVATEAM), 3% BLANCOTAN BC (SILVATEAM), 2% BIOPLEN MB (BIOKIMICA), 60 minutes; 2% IDROSOL S (FGL), 1% honey, 60 minutes; 0.5% oxalic acid, 30 minutes; 2% SELLATANLV (TFL), 60 minutes, remove from drum;

[0130] 15. Riding a horse;

[0131] 16. Squeeze out the water;

[0132] 17. Thermal stretching;

[0133] 18. Hanging and airing: Day 1: Temperature 20℃, humidity 80-85%; Day 2: Temperature 25℃, humidity 60-65%; Day 3: Temperature 30℃, humidity 50%;

[0134] 19. Vibration softens;

[0135] 20. Roll pressing;

[0136] 21. Warehousing;

[0137] 22. Floor covering test.

[0138] The following table shows the test results of the product obtained in this embodiment:

[0139] Surface scratch resistance UNI 9428 5 = maximum 1 = minimum 4 Surface abrasion resistance TABER UNI9115 = Maximum 1 = Minimum 4 Surface resistance to cold liquids UNI EN 12720 5 - Maximum 1 = Minimum 4.43 Dimensional stability EN 1910:2001 Customer Requirements Volatile organic compounds (VOCs) UNI EN 13501 Grade A Fire protection classification of products and building components UNI EN ISO 16000-9:2006 Class B - S1, D0

[0140] Example 2

[0141] A tanning process for fully vegetable-tanned cowhide flooring includes the following steps:

[0142] 1. Raw hide assembly and batching;

[0143] 2. Rawhide cutting: Starting from the tail, cut along the midrib for 130cm in length and 140cm in width perpendicular to the midrib. Butt is used for heavy leather tanning, and Shoulder is used for light leather products.

[0144] 3. Pre-soaking: Pre-soaking water temperature 18-22℃, liquor ratio 150%, 0.2% BORRON A (TFL), 0.2% soda ash, run for 60 minutes, drain; Main soaking: Control internal temperature 22-24℃, liquor ratio 150%, 0.1% BORRON A (TFL), 0.2% soda ash, 0.1% sodium sulfide, run for 60 minutes, drain, liquor ratio 150%, internal temperature 22-24℃, add 7% sodium chloride, adjust Baumé degree to 4-4.5, switch to automatic mode and run for 3 minutes, stop for 27 minutes, repeat 4 times, add 0.25% DIX-005 (Borska), 0.1% BORRON A (TFL), 0.2% BORRON SE (TFL), 0.15% PELLVIT MN-A (TFL), 0.5% ERHAVIT SP(TFL), after running for 90 minutes, switch to automatic mode (run for 5 minutes, stop for 25 minutes, for a total of 10 times), then run for 480 minutes, remove the meat from the drum;

[0145] 4. Lime Impregnation: At room temperature and a liquid ratio of 0%, add 0.2% BORRON SE (TFL), 0.6% lime powder, 2.2% ERHAVITHS2 (TFL), and 0.2% Erhavit DMC (TFL). Rotate for 30 minutes, stop for 15 minutes, rotate for 30 minutes, add 1.5% sodium hydrosulfide, 3% sodium sulfide, 4.5% lime, 0.3% ERHA GM3034 (TFL), 1% glucose, and 0.5% BIOSINT CG (BIOKIMICA). Rotate for 60 minutes, check for shedding, switch to automatic mode (rotate for 5 minutes, stop for 55 minutes, repeat 20 times), add 60% warm water, control the internal temperature at 26-27℃, add 0.3% ERHA GM3034 (TFL), 0.1% BORRON A (TFL), and 1% sodium sulfide, rotate for 330 minutes, and remove from the drum.

[0146] 5. Remove the flesh from the gray skin;

[0147] 6. Deashing and softening: Pre-deashing temperature 30℃, liquid ratio 150%, 0.3% ammonium sulfate, rotate for 30 minutes, then switch to automatic mode (rotate for 5 minutes, stop for 55 minutes), and run in automatic mode for 12 hours; Main deashing and softening temperature 35℃, liquid ratio 50%, 0.7% ammonium sulfate, 1% DERMASCAL ASB (TFL), 0.5% sodium bisulfite, 0.2% BORRON SAF (TFL), rotate for 30 minutes, add 0.5% ammonium sulfate, 0.5% sodium bisulfite, and 0.5% glucose, rotate for 90 minutes, check the deashing status: pH: 7.0, cut fully transparent, drain and wash twice;

[0148] 7. Pickling-Pretanning: Temperature 20℃, liquor ratio 60%, add 8% sodium sulfate, 0.2% EDTA, adjust Baumé degree to 8-10, add 3% SINTERAL PL6 (ALPA) and rotate for 120 minutes, add 0.2% formic acid and rotate for 60 minutes, add 4% TANIGAN CHN (LANXESS) and rotate for 300 minutes, switch to automatic mode (rotate for 5 minutes and stop for 55 minutes), run in automatic mode for 12 hours, add 4% WEIBULL LIGHT (TANAC) and rotate for 120 minutes;

[0149] 8. Tanning: Use a 15T (ton) tanning vat, add 4T of 20℃ water, 10T of circulating old tanning liquor, 4% sodium chloride, and 1% soda ash. Adjust the Baumé degree to 4.0 and the pH to 4.5-4.8. Add the hides and set the automatic mode (30 minutes forward rotation, 30 minutes reverse rotation). Run the automatic mode for 12 hours, adjusting the temperature to 25℃. Add 1% sodium bisulfite, 25% WEIBULL LIGHT (TANAC), 10% TTO (Tingjiang New Materials), and 2% LECOSIN PS (FGL). Check the Baumé degree to 6.0-6.5 and the pH to 4.6-4.8. Set the automatic mode (30 minutes of rotation, 30 minutes of stop) and run the automatic mode for 12 hours. Add 0.5% ERHA GM3995 (TFL), 25% TCR (Tingjiang New Materials), and 10% WEIBULL... LIGHT (TANAC), 10% TTO (Tingjiang New Materials), 2% LECOSIN PS (FGL), 1% Sodium Bisulfite, 1% IDROSOL S (FGL), 0.5% BK55 (Bauska). Set to automatic mode (run for 30 minutes, stop for 30 minutes). Run in automatic mode for 12 hours. Check Baumé: 8.5-9.0, pH: 4.6-4.8. Add 5% BLANCOTAN BC (SILVATEAM), 10% TCR (Tingjiang New Materials), 1% LECOSIN PS (FGL), 1% TRUPONOL FSF (TRUMPLER), 3% BIOSINT. CG (BIOKIMICA), 1% oxalic acid, set to automatic mode (run for 30 minutes, stop for 30 minutes), run in automatic mode for 12 hours, check Baumé degree: 9.0-9.5, pH: 4.0-4.2, add 0.3% sodium bisulfite, set to automatic mode (run for 30 minutes, stop for 30 minutes), run in automatic mode for 12 hours, check Baumé degree: 9.0-9.5, pH: 4.0-4.2, peel off, collect the tanning liquor from this process as recycled old tanning liquor for tanning tanks;

[0150] If there is no remaining recycled tanning liquor in the above process, 10T of water at 20℃, 30% WEIBULL LIGHT, 20% TTO tannin, and 0.5% sodium bisulfite can be added as a substitute.

[0151] Rotary drum tanning: temperature 30℃, 30% water, 10% CHESTNUT (SILVATEAM), 5% BLANCOTAN BC (SILVATEAM), 5% TTO (Tingjiang New Materials), 0.5% IDROSIN ME (FGL), 0.5% ERHA GM 3995. Rotate for 12 hours, then switch to automatic mode (rotate for 10 minutes, stop for 50 minutes), run in automatic mode for 12 hours, add 0.5% BK55 (Bauska), rotate for 4 hours, add 50% water and raise the temperature to 35℃, add 50% of the circulating drum old tanning liquor, 0.5% oxalic acid, 0.5% sodium bisulfite, 0.2% EDTA, rotate for 60 minutes, remove from drum and set up. Collect the tanning liquor from this process as the circulating drum old tanning liquor.

[0152] If there is no remaining recycled tanning liquor from the drum during the above process, 50% 35℃ water, 2% CHESTNUT (SILVATEAM), 1% BLANCOTAN BC (SILVATEAM), and 1% TTO (Tingjiang New Materials) can be added as substitutes.

[0153] 9. Let it stand for one week;

[0154] 10. Dewatering: Through-type dewatering;

[0155] 11. Cutting: Cut straight along the central ridge;

[0156] 12. Evenly cut: Cut to a thickness of 5.0 mm;

[0157] 13. Retanning: Temperature 35℃, liquor ratio 10%, rotating for 60 minutes, 1% magnesium sulfate, rotating for 60 minutes, 6% BASYNTANDLE (BASF), 2% BIOPLEN FFR, 2% CHESTNUT

[0158] (SILVATEAM), 3% BLANCOTAN BC (SILVATEAM), 2% BIOPLEN MB (BIOKIMICA), 60 minutes; 2% IDROSOL S (FGL), 1% honey, 60 minutes; 0.5% oxalic acid, 30 minutes; 2% SELLATANLV (TFL), 60 minutes, remove from drum;

[0159] 14. To ride a horse;

[0160] 15. Squeeze out the water;

[0161] 16. Thermal stretching;

[0162] 17. Hanging and airing: Day 1: Temperature 20℃, humidity 80-85%; Day 2: Temperature 25℃, humidity 60-65%; Day 3: Temperature 30℃, humidity 50%;

[0163] 18. Vibration softens;

[0164] 19. Roll pressing;

[0165] 20. Warehousing;

[0166] 21. Floor covering test.

[0167] The following table shows the test results of the product obtained in this embodiment:

[0168] Surface scratch resistance UNI 9428 5 = maximum 1 = minimum 4 Surface abrasion resistance TABER UNI9115 = Maximum 1 = Minimum 4 Surface resistance to cold liquids UNI EN 12720 5 - Maximum 1 = Minimum 4.82 Dimensional stability EN 1910:2001 Customer Requirements Volatile organic compounds (VOCs) UNI EN 13501 Grade A+ Fire protection classification of products and building components UNI EN ISO 16000-9:2006 Class B - S1, D0

[0169] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A tanning process for all-vegetable tanned cowhide flooring, characterized in that: Includes the following steps: Raw hides are pre-treated and then subjected to pickling, tanning, intermediate treatment, retanning, and post-treatment to obtain finished leather. A first pretanning agent is added during the pickling and pretanning process; The tanning process includes the following steps: adding water and a first tanning agent to a trough and rotating; adding a second tanning agent and rotating; adding a third tanning agent and rotating; adding a fourth tanning agent and rotating; adding a fifth tanning agent and rotating; Then it is transferred to a rotating drum, where water and the sixth tanning agent are added and the drum is rotated; the seventh tanning agent is added and the drum is rotated. The retanning process includes the addition of a first retanning agent and a second retanning agent. The first pretanning material comprises 3% non-expanding acid, 2% aldehyde tanning agent, and 4% naphthalene synthetic tanning agent; Alternatively, the first pretanning material may include 3% non-expanding acid, 4% aromatic sulfonic acid synthetic tanning agent, and 4% tannin from Vitex negundo bark; The first tanning agent includes 1% sodium bisulfite, 2% naphthalene synthetic tanning agent, 2% sodium formate, 15% chamomile bark tannin, and 10% styrax tannin; The second tanning agent includes 12% saccharified chestnut tannin, 1% sodium bisulfite, 6% vitex bark tannin, 6% hardwood tannin, 1% naphthalene-based synthetic tanning agent, and 1% sulfite-treated fish oil; The third tanning agent includes 0.5% oxalic acid, 5% sulfone-based alternative synthetic tanning agent, 10% chestnut tannin, 1% naphthalene-based synthetic tanning agent, and 1% sulfite-treated fish oil; The fourth tanning agent includes 12% saccharified chestnut tannin, 12% chestnut tannin, 0.5% EDTA, and 1% sodium bisulfite; The fifth tanning agent includes 0.3% sodium bisulfite and 0.5% oxalic acid; Alternatively, the first tanning agent may include 4% sodium chloride and 1% soda ash; The second tanning agent includes 1% sodium bisulfite, 25% tannin from vitex bark, 10% tannin from hardwood, and 2% naphthalene-based synthetic tanning agent; The third tanning agent includes 0.5% anti-snagging agent, 25% saccharified chestnut tannin, 10% vitex bark tannin, 10% hardwood tannin, 2% naphthalene-based synthetic tanning agent, 1% sodium bisulfite, 1% sulfite whale oil, and 0.5% antifungal agent. The fourth tanning agent includes 5% sulfone-based alternative synthetic tanning agent, 10% saccharified chestnut tannin, 1% naphthalene-based synthetic tanning agent, 1% sulfite-treated fish oil, 3% liming aid, and 1% oxalic acid; The fifth tanning agent includes 0.3% sodium bisulfite; The sixth tanning agent includes 10% chestnut tannin, 5% sulfone-based alternative synthetic tanning agent, 5% hardwood tannin, 0.5% mineral oil, and 0.5% anti-snagging agent; The seventh tanning agent comprises 0.5% mildew inhibitor, 50% water, 0.5% oxalic acid, 0.5% sodium bisulfite, and 0.2% EDTA; The first retanning agent includes 6% phenolic tanning agent, 2% melamine resin tanning agent, 2% chestnut tannin, 3% sulfone-based alternative synthetic tanning agent, 2% filler resin, 2% sulfite whale oil, and 1% honey; The second retanning agent includes 2% highly astringent sulfone synthetic tanning agent.

2. The tanning process for a fully vegetable-tanned cowhide flooring according to claim 1, characterized in that: The pretreatment includes raw hide batching, raw hide cutting, soaking in water, soaking in ash, removing flesh from ash-soaked hides, and deashing and softening. The intermediate processing includes resting on a flat surface, squeezing out water, slicing, and evenly shaving. The post-processing includes stretching, dewatering, heat stretching, hanging drying, vibrating softening, rolling, and warehousing.

3. The tanning process for a fully vegetable-tanned cowhide flooring according to claim 2, characterized in that: The immersion process includes the following steps: Pre-soaking: Add water, wetting and dispersing agent, soda ash, rotate and drain; Main soaking: Add wetting and dispersing aids, soda ash, and sodium sulfide, rotate and drain; add salt, adjust Baumé degree to 4-4.5, rotate; add bactericide, wetting and dispersing aids, degreasing agent, soaking pH stabilizer, and soaking ash aid, rotate and remove meat from drum.

4. The tanning process for a fully vegetable-tanned cowhide flooring according to claim 2, characterized in that: The impregnation process includes the following steps: adding degreasing agent, lime powder, impregnation aid, and enzyme-containing impregnation aid, and rotating; adding sodium hydrosulfide, sodium sulfide, lime, anti-snagging agent, glucose, and impregnation aid and rotating; adding water, anti-snagging agent, wetting and dispersing aid, and sodium sulfide, and rotating before exiting the drum.

5. The tanning process for a fully vegetable-tanned cowhide flooring according to claim 2, characterized in that: The deashing and softening process includes the following steps: adding water and ammonium sulfate, rotating and then draining; adding water, ammonium sulfate, deashing agent, and sodium bisulfite, rotating; adding ammonium sulfate, deashing agent, sodium bisulfite, and glucose, rotating; adding emulsifier and softening enzyme, rotating and then draining, and washing with water.

6. The tanning process for a fully vegetable-tanned cowhide flooring according to claim 2, characterized in that: The deashing and softening process includes the following steps: adding water and ammonium sulfate, rotating and then draining; adding water, ammonium sulfate, deashing agent, sodium bisulfite, and emulsifier and rotating; adding ammonium sulfate, sodium bisulfite, and glucose, rotating and then draining, followed by washing with water.

7. The tanning process for a fully vegetable-tanned cowhide flooring according to claim 2, characterized in that: The hanging drying process includes the following steps: Day 1: Temperature 20℃, Humidity 80-85%; Day 2: Temperature 25℃, Humidity 60-65%; Day 3: Temperature 30℃, Humidity 50%.

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