Ecological plant tanning material-zeolite tanning agent combined chrome-free tanning production process

Abstract

The invention discloses an ecological plant tanning material-zeolite tanning agent combined chrome-free tanning production process. The tanning technology sequentially comprises the following working procedures of raw material leather grouping, pre-soaking, fleshing, main soaking, liming, leather splitting, deliming, softening, pH and bare leather adjusting, Tara tanning, zeolite tanning, standing, water squeezing, shaving, water washing, neutralizing, filling and retanning, filling, dyeing, fat liquoring, fixing, drying and after-finishing.

Description

Technical Field

[0001] The invention belongs to the technical field of leather making, and relates to a chrome-free tanning leather production process combining an ecological vegetable tanning material and a zeolite tanning agent. Background Art

[0002] Leather is mainly composed of collagen fibers, which are highly hydrophilic before being treated and are easily affected by moisture, deformed and rotten. The purpose of tanning is to change the properties of collagen in leather through chemical or physical methods to make it more stable and durable.

[0003] The main tanning processes include chrome tanning, organic tanning, vegetable tanning, aluminum tanning, oil tanning, etc. Among them, vegetable tanning has the longest history, chrome tanning is the dominant one, and there is also a chrome-free tanning system represented by aldehyde tanning represented by glutaraldehyde and formaldehyde. In view of the ecological unsustainability of chrome tanning and aldehyde tanning, the modern leather industry tanning system has an aldehyde-free and metal-free organic tanning system and a zeolite tanning system.

[0004] The following is a basic introduction to chrome tanning, aldehyde tanning, vegetable tanning, organic tanning and zeolite tanning, as well as a basic summary of the various tanning properties.

[0005] As for chrome tanning: chrome tanned leather has excellent moisture and heat stability and storage resistance, as well as good physical and mechanical properties and sensory properties. However, when chrome tanning agents are used for tanning and retanning, they cannot be completely absorbed by the leather collagen fibers, and 20-35% of the chromium is discharged with the wastewater, causing certain pollution to the ecological environment. Moreover, wastewater and waste containing chromium are all classified as containing heavy metals, which are difficult to treat and have high treatment costs. In addition, under certain conditions, the trivalent chromium in the chrome tanning agent may be converted into toxic and harmful hexavalent chromium, which is difficult to meet the requirements of the "Genuine Leather Mark Ecological Leather Product Specifications". Therefore, the ecological sustainability of chrome tanned leather is an unavoidable defect, and it may be gradually replaced by other eco-friendly tanning systems.

[0006] For aldehyde tanning: commonly used aldehyde tanning agents are formaldehyde and glutaraldehyde. Aldehyde can block the amino groups on the side chains of collagen polypeptide chains and form a mesityle bridge between two polypeptide chains, so that the adjacent amino groups between the polypeptide chains are "stitched" to produce tanning. Aldehyde tanned leather generally has good sweat resistance and water washing resistance. This is because the aldehyde tanning agent molecules are closely combined with the rawhide collagen molecules during the tanning process, which increases the stability of the leather and its ability to resist chemicals; aldehyde tanned leather also has a certain ability to resist acids, alkalis, oxidants and reducing agents, making it more durable in certain specific environments. Leather tanned with aldehyde alone has poor fullness, and the finished leather is flat, thin, hard and brittle, and has low mechanical strength, which may limit its application in certain fields that require higher mechanical strength; chemical substances such as formaldehyde that may be used in the aldehyde tanning process may have certain impacts on the environment and human health if not handled properly, although they are used in combination with other tanning agents during the tanning process to reduce this risk. In summary, aldehyde tanning, as an important tanning method, has its unique advantages and certain application limitations.

[0007] Regarding vegetable tanning: Vegetable tanning is a leather tanning method with a long history. It uses natural tannins in plants (such as tannins, flavonoids, etc.) to chemically combine with collagen fibers in raw hides to achieve leather tanning. Modern vegetable tanning mainly uses tannins extracted from plants (the main component is tannin) for tanning. It is a production process for manufacturing natural plant-based leather based on natural plant-based raw materials and their derived chemicals. Plant tannins are a class of compounds with polyphenol structures. They can react with amino, hydroxyl and other functional groups in proteins to form stable chemical bonds. The presence of these chemical bonds makes the leather have good water resistance, heat resistance and chemical resistance after tanning. Vegetable tanning gives genuine leather pollution-free properties (no aldehyde, no metal system), a comfortable smell, a good carbon footprint performance, and excellent sustainability prospects. Since the binding ability between vegetable tannins and leather collagen is relatively weak and the water washing resistance is poor, especially under the conditions of high temperature and mechanical force, the binding force is easily destroyed. In the subsequent fatliquoring process, at high temperature, the vegetable tannins are easy to migrate out of the leather, reducing the tanning effect and the physical properties of the tanned leather.

[0008] For organic tanning: polyhydroxy organic compounds can react chemically with the collagen fibers in the leather to form cross-linked bonds, which significantly enhances the stability of the leather. This cross-linked structure makes the leather more tear-resistant and flex-resistant, increasing its service life. Through tanning with polyhydroxy organic compounds, the shrinkage temperature of the leather is increased, the moisture and heat stability is enhanced, and the ability to resist chemicals such as acids, alkalis, and enzymes is also improved. These performance improvements allow the leather to maintain a good condition in a variety of environments. The relatively high cost is an obstacle to the promotion of organic tanning agents. The synthesis and purification process of polyhydroxy organic compounds may be relatively complicated, resulting in relatively high costs, which may increase the production cost of leather products and limit their application in certain fields. In addition, some specific properties of organic tanned leather may not be as good as chrome-tanned leather. Although leather tanned with polyhydroxy organic compounds performs well in many aspects, it may still be inferior to traditional chrome-tanned leather in certain specific properties, such as coloring properties, softness and elongation, which may limit its application in leather products that require these specific properties. For zeolite tanning: Zeolite, as a mineral, has unique physical and chemical properties, such as porosity, adsorption, ion exchange capacity, etc. During the tanning process, zeolite may interact with collagen in leather through the active sites on its surface, thereby changing the properties of leather. Zeolite tanning provides a new way of leather making, with advantages throughout the entire value chain, and its advantages are mainly reflected in safety, environmental protection and excellent leather performance. Due to its cationic properties, zeolite tanning can increase the material absorption during retanning and dyeing, thereby reducing the use of chemical materials in this process and reducing the COD (chemical oxygen demand) of wastewater. The sludge from zeolite tanning wastewater treatment and the residues after tanning operations are easy to biodegrade and compost, making the entire leather tanning process safer and more environmentally friendly. Compared with traditional chrome tanning agents, the uniqueness of zeolite is that it improves the sustainable benefits of the leather industry while providing excellent leather performance. In addition, the white wet leather tanned by zeolite will present a bright white color, which gives the zeolite-tanned leather products a unique white color and excellent leather properties, and highlights certain advantages in terms of leather grain firmness, leather physical properties, light resistance, etc. Zeolite tanning also has certain shortcomings. Compared with chrome-tanned leather, it is not as thermally stable as chrome-tanned leather, and it also lacks the softness, elasticity and fullness of chrome-tanned leather. Compared with other chrome-free tanning systems, zeolite-tanned leather is slightly lacking in fullness.

[0009] Summarize the advantages and disadvantages of the above tanning Figure 1 From the perspective of eco-friendliness and sustainable development, various existing tanning evaluations are as follows Figure 2 shown.

[0010] The sustainable development requirements of the leather industry and the performance requirements of leather applications require the consideration of a tanning system that generally meets the functional requirements of leather products, which can have both intentional sustainability and eco-friendly labels, while achieving the characteristics of chrome tanning and some special chrome-free tanning (vegetable tanning, aldehyde tanning), and meet the various properties and requirements of automotive interior leather, such as excellent thermal stability (shrinkage temperature), excellent softness and elasticity, firm and fine grain, excellent fullness, excellent various physical and chemical properties, etc.; therefore, it is necessary to design a chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent to solve the above problems. Summary of the invention

[0011] The purpose of the present invention is to solve the above problems in the prior art and to propose a chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent.

[0012] To achieve the above-mentioned purpose, the technical scheme of the present invention is: a chrome-free tanning leather production process combining ecological vegetable tanning agent and zeolite tanning agent, characterized in that it comprises the following steps in sequence: raw hide batching → pre-immersion → fleshing → main immersion → liming → splitting → deliming → softening → pH and bare hide adjustment → Tara tanning → zeolite tanning → standing → squeezing → shaving → washing → neutralization → filling retanning → filling → dyeing → greasing → fixing → drying → finishing.

[0013] In the pH and skin adjustment process, the softened skin is washed with water and treated with enzymes to a pH of 7.4-7.9.

[0014] The Tara tanning process uses Tara tannin extract, the total amount of which is 6-12% of the weight of the gray hide, the liquid ratio is 50-60%, the temperature is controlled at 30-38°C; and the end point pH is controlled at 3.5-3.9.

[0015] The zeolite tanning process uses 6-10% zeolite tanning agent, liquid ratio 50-60%, temperature controlled at 30-35°C, initial pH: 2.4-2.9, end pH: 4.7-4.9, baking soda is used for alkali extraction, and the end temperature is 42-45°C.

[0016] In the neutralization process, a neutralizing tanning agent, sodium formate combined with baking soda is used, and the end point pH is controlled at 4.8-5.5 and the temperature is controlled at 30-40°C.

[0017] In the filling and retanning process, polymer fatliquor, polymer retanning agent and acrylic retanning agent are first added, and then acrylic retanning agents with large and medium molecular weights and neutral filling materials are added, and then amino resin is supplemented for retanning and filling.

[0018] The filling and retanning process and the dyeing process adopt a same-bath process.

[0019] The fatliquor process adopts a split bath process, with a liquid ratio of 50-200%, a temperature controlled at 45-48° C., and protein fillers, acrylic resin tanning agents, polymer fatliquors, synthetic oils, silicon-containing fatliquors, and lecithin are added for fatliquor.

[0020] Furthermore, the pH and bare skin adjustment process is specifically as follows: the amount of reagent is determined by the percentage of the mass of the gray skin obtained in the peeling process, washed with water at 35°C to a bath pH of 7.4-7.9, then adjusted to 150% liquid ratio, the temperature is controlled at 30-36°C, and treated with 0.2-0.6% enzyme for 60-120 minutes.

[0021] Furthermore, the Tara tanning process is specifically as follows: the amount of reagents is determined by the percentage of the mass of the gray leather obtained in the peeling process, 50-60% of water is added to the drum, 0.1-1% of the iron remover, 0.5-3% of the dispersant, and 6-12% of the Tara tannin tanning agent are added, and the drum is rotated at a temperature of 30-38°C for 120-180 minutes; 100-150% of water is added, and the drum is rotated at a temperature of 38-42°C for 30-120 minutes; formic acid is added to adjust the pH value of the bath liquid to 3.5-3.9; draining; 150-200% water, 0.5-1% oxalic acid, 0.5-1% formic acid, washing with water for 15-30 minutes; draining.

[0022] Furthermore, the zeolite tanning process is specifically as follows: the amount of reagent used is determined by the percentage of the mass of the gray leather obtained in the peeling process, 50-60% of water is added to the drum, the temperature in the drum is adjusted to 30-35°C, the pH of the bath liquid is adjusted to 2.4-2.9, 6-10% of zeolite tanning agent is added, and the drum is rotated for 90-180 minutes; the alkali is extracted with baking soda to a final pH of 4.7-4.9, 100-150% of water is added to adjust the temperature to 42-45°C, and the drum is rotated for 60-180 minutes; the liquid is drained; the water is washed and a mildew inhibitor is added; the liquid is drained, the drum is removed, and the drum is mounted and left to stand.

[0023] Furthermore, the neutralization process is specifically as follows: the amount of reagent used is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 70-200% of water is added to the drum, the temperature in the drum is adjusted to 30-40°C, 0.5-3% of synthetic tanning agent and sodium formate with neutralizing effect are added, baking soda is added, and the pH value of the bath liquid is adjusted to 4.8-5.5.

[0024] Furthermore, the filling and retanning process is specifically as follows: the amount of reagents used is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 1-5% of a polymer tanning agent with an oiling effect and 1-5% of an acrylic polymer tanning agent are added to the neutralization bath, and rotated for 40-60 minutes; 0.5-5% of a characteristic acrylic resin tanning agent and 1-6% of anionic acrylic resin tanning agent are added, and rotated for 50-90 minutes; 1-8% of acrylic acid with different molecular weights are added, and rotated for 40-90 minutes.

[0025] Furthermore, the filling process is specifically as follows: the amount of reagents used is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 0.5-5% dicyandiamide resin tanning agent and 0.5-5% melamine resin tanning agent are added to the same bath, and rotated for 30-90 minutes.

[0026] Furthermore, the dyeing process is specifically as follows: the amount of reagent is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 0.5-5% dye is added after tanning, 0.5-5% condensation vegetable tanning agent, 0.5-6% hydrolysis vegetable tanning agent, 1-10% alternative synthetic tanning agent, 2-10% auxiliary synthetic tanning agent, 0.5-3% oil is added, and the leather is rotated for 60-120 minutes; 100-200% hot water is added, the temperature is raised to 45-48°C, formic acid is added for fixing, the pH is adjusted to 4.0-4.4, drainage is carried out, hot water washing is carried out, and drainage is carried out.

[0027] Furthermore, the greasing process is specifically as follows: the amount of reagent is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 150% of water is added, the temperature in the drum is adjusted to 45-48°C, 0.5-6% of protein filler, 0.5-6% of polyacrylic acid greasing agent is added, and the drum is rotated for 30-60 minutes, and then 2-8% of anionic synthetic oil, 0.5-5% of silicon-containing greasing agent, 0.5-5% of phospholipids, 0.5-6% of polymer greasing agent are added, and the drum is rotated for 60-90 minutes; 1-3% formic acid is added in three times, and the drum is rotated for a total of 40-60 minutes, and the pH value of the bath liquid is adjusted to 3.3-3.8; and the liquid is drained.

[0028] Furthermore, the post-finishing process specifically includes mounting and standing → squeezing and stretching → vacuum drying → hanging and drying → oscillating and softening → finishing and painting.

[0029] By adopting the above technical solution, the beneficial effects of the present invention are: 1. This process can produce eco-friendly, environmentally friendly and sustainable chrome-free tanned automotive interior leather; 2. This technical solution uses a plant tara tanning agent combined with a natural mineral source zeolite tanning agent to prepare white wet leather, and uses special retanning, dyeing and oiling to prepare leather embryos; 3. The tannin of the vegetable tannin tara tannin contains almost no color components, and can produce bright and light-resistant light-colored leather. Compared with other vegetable tannins, tara tannin can make leather particles have higher load-bearing capacity and tensile strength in the elongation at break test. In addition, due to its small molecular weight, tara tannin can also give leather good fullness and softness, and maintain a delicate and tight grain surface; compared with other vegetable tannins, leather tanned with tara tannin has higher crack resistance; 4. White wet leather made by tanning with zeolite combined with tara tannin will appear bright white. The reason is that zeolite is evenly and deeply dispersed in collagen. During the tanning process, the zeolite structure forms a network that evenly covers the collagen, which gives the product a unique white color and excellent leather properties, highlighting its advantages in leather grain firmness, leather physical properties, light resistance and heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the advantages and disadvantages of various tanning processes in the background art.

[0031] Figure 2 is a schematic diagram of various tanning evaluations in the background art.

[0032] Figure 3 It is a schematic diagram of the process steps of the present invention. DETAILED DESCRIPTION

[0033] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0034] like Figure 3 As shown, the chrome-free tanning leather production process combining ecological vegetable tanning agent and zeolite tanning agent includes the following steps in sequence: raw hide batching → pre-immersion → fleshing → main immersion → liming → splitting → deliming → softening → pH and bare hide adjustment → Tara tanning → zeolite tanning → standing → squeezing → shaving → washing → neutralization → filling and retanning → filling → dyeing → greasing → fixing → drying → finishing.

[0035] In the pH and bare skin adjustment process, the softened bare skin is washed with water and treated with enzymes to a pH of 7.4-7.9; specifically, the pH and bare skin adjustment process is as follows: the amount of reagent is determined by the percentage of the mass of the gray skin obtained in the peeling process, washed with water at 35°C to a bath pH of 7.4-7.9, then adjusted to 150% liquid ratio, the temperature is controlled at 30-36°C, and treated with 0.2-0.6% enzyme for 60-120 minutes.

[0036] The Tara tanning process uses Tara tannin, the total amount is 6-12% of the weight of the gray leather, the liquid ratio is 50-60%, the temperature is controlled at 30-38°C; the end point pH is controlled at 3.5-3.9; specifically: the Tara tanning process is specifically as follows: the amount of reagent is determined by the percentage of the mass of the gray leather obtained in the peeling process, 50-60% of water is added to the drum, 0.1-1% of iron remover, 0.5-3% of dispersant, 6-12% of Tara tannin tanning agent are added, and the drum is rotated at a temperature of 30-38°C for 120-180 minutes; 100-150% of water is added, and the drum is rotated at a temperature of 38-42°C for 30-120 minutes; formic acid is added to adjust the pH value of the bath liquid to 3.5-3.9; drain; 150-200% water, 0.5-1% oxalic acid, 0.5-1% formic acid, wash with water for 15-30 minutes; drain.

[0037] The zeolite tanning process uses 6-10% zeolite tanning agent, liquid ratio 50-60%, temperature controlled at 30-35°C, initial pH: 2.4-2.9, end pH: 4.7-4.9, baking soda is used to extract alkali, and the end temperature is 42-45°C; specifically: the zeolite tanning process is specifically as follows: the amount of reagent is determined by the percentage of the mass of the gray leather obtained in the peeling process, 50-60% water is added to the drum, the temperature in the drum is adjusted to 30-35°C, the pH of the bath liquid is adjusted to 2.4-2.9, 6-10% zeolite tanning agent is added, and the drum is rotated for 90-180 minutes; baking soda is used to extract alkali to the final pH: 4.7-4.9, 100-150% water is added to adjust the temperature to 42-45°C, and the drum is rotated for 60-180 minutes; liquid is drained; water is washed and mildew inhibitor is added; liquid is drained, the drum is removed, and the drum is mounted and left to stand.

[0038] In the neutralization process, a neutralizing tanning agent is used, sodium formate is combined with a certain amount of baking soda, the end point pH is controlled at 4.8-5.5, and the temperature is controlled at 30-40°C; specifically: the neutralization process is specifically as follows: the amount of reagent is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 70-200% of water is added to the drum, the temperature in the drum is adjusted to 30-40°C, 0.5-3% of a synthetic tanning agent and sodium formate with a neutralizing effect are added, baking soda is added, and the pH value of the bath liquid is adjusted to 4.8-5.5.

[0039] In the filling and retanning process, polymer fatliquor, polymer retanning agent and acrylic retanning agent are first added, and then large and medium molecular weight acrylic retanning agents are added. The acrylic retanning agent uses an existing product that can be purchased; neutral filling material, and then amino resin is added for retanning and filling; specifically: the filling and retanning process is specifically as follows: the amount of reagents is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 1-5% of polymer tanning agent with fatliquor effect and 1-5% of acrylic polymer tanning agent are added to the neutralization bath above, and rotated for 40-60 minutes; 0.5-5% of special acrylic resin tanning agent and 1-6% of anionic acrylic resin tanning agent are added, and rotated for 50-90 minutes; 1-8% of acrylic acid of different molecular weights are added, and rotated for 40-90 minutes.

[0040] The filling, retanning and dyeing processes adopt the same bath process.

[0041] The greasing process adopts a separate bath process, with a liquid ratio of 50-200%, a temperature controlled at 45-48°C, and protein fillers, acrylic resin tanning agents, polymer fatliquors, synthetic oils, silicon-containing fatliquors, and phospholipids are added for fatliquor. Specifically, the greasing process is as follows: the amount of reagents is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 150% of water is added, the temperature in the drum is adjusted to 45-48°C, 0.5-6% of protein fillers and 0.5-6% of polyacrylic acid fatliquors are added, and the mixture is rotated for 30-60 minutes, and then 2-8% of anionic synthetic oils, 0.5-5% of silicon-containing fatliquors, 0.5-5% of phospholipids, and 0.5-6% of polymer fatliquors are added, and the mixture is rotated for 60-90 minutes; 1-3% formic acid is added in three times, and the mixture is rotated for a total of 40-60 minutes, and the pH value of the bath liquid is adjusted to 3.3-3.8; and the liquid is drained.

[0042] The filling process is specifically as follows: the amount of reagents used is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 0.5-5% dicyandiamide resin tanning agent and 0.5-5% melamine resin tanning agent are added to the same bath, and rotated for 30-90 minutes.

[0043] The dyeing process is specifically as follows: the amount of reagents is determined by the percentage of the mass of the white wet leather obtained in the shaving process, 0.5-5% dye is added after tanning, 0.5-5% condensation vegetable tanning agent, 0.5-6% hydrolysis vegetable tanning agent, 1-10% alternative synthetic tanning agent, 2-10% auxiliary synthetic tanning agent, 0.5-3% oil is added, and the leather is rotated for 60-120 minutes; 100-200% hot water is added, the temperature is raised to 45-48°C, formic acid is added for fixing, the pH is adjusted to 4.0-4.4, drainage is carried out, hot water washing is carried out, and drainage is carried out.

[0044] The post-finishing process specifically includes mounting and standing → squeezing water and stretching → vacuum drying → hanging and drying → oscillating and softening → finishing and painting.

[0045] Tara tannin tanning agent is combined with zeolite tanning agent for tanning. The polyhydroxy structure contained in Tara tannin, the collagen fiber structure of bare skin, and the silicic acid structure of zeolite tanning agent can form cross-linking and covering effects, resulting in a vegetable-boiler synergistic tanning effect, while enhancing the fixing effect of Tara and zeolite to improve the absorption stability of the vegetable tanning agent, so that the water resistance, organic solvent resistance and shrinkage temperature of the resulting crust leather are improved, and the distribution of the vegetable tanning agent on each layer of the crust leather is relatively uniform. The resulting crust leather has a fine grain and good firmness, and at the same time has good softness, fullness and elasticity, as well as wet heat stability, which conforms to and meets the characteristics and needs of automotive interior leather products.

[0046] The main tanning system of this process uses tara tannin and zeolite tanning agent materials that are completely natural sources, and has excellent performance in terms of product carbon footprint and subsequent natural degradation and composting cycles after the product life cycle.

[0047] The eco-friendly and sustainable vegetable-boiling tanned automotive leather produced by this process has a shrinkage temperature of up to 100°C (as shown in the table below), and its physical, mechanical and sensory properties meet the requirements of automotive interior leather.

[0048]

[0049] This production technology and production process meet the requirements of clean environmental protection. The automotive interior leather produced meets the requirements of green, safe and environmentally friendly products. In particular, it fully meets the requirements and trends of the automotive industry in terms of eco-friendliness and sustainability, that is, it meets the chrome-free and formaldehyde-free chrome-free tanning production process while meeting the requirements of low carbon and recyclable concepts, and is suitable for promotion and application in leather production.

[0050] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent, characterized in that: The process includes the following steps in sequence: raw hide batching → pre-soaking → fleshing → main soaking → liming → splitting → deliming → softening → pH and bare hide adjustment → Tara tanning → zeolite tanning → standing → squeezing → shaving → washing → neutralization → filling and retanning → filling → dyeing → fatliquoring → fixing → drying → finishing.

2. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 1 is characterized in that: In the pH and skin adjustment process, the softened skin is washed with water and treated with enzymes to a pH of 7.4-7.

9.

3. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 1 is characterized in that: The Tara tanning process uses Tara tannin extract, the total amount of which is 6-12% of the weight of the gray hide, the liquid ratio is 50-60%, the temperature is controlled at 30-38°C; and the end point pH is controlled at 3.5-3.

9.

4. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 1 is characterized in that: The zeolite tanning process uses 6-10% zeolite tanning agent, liquid ratio 50-60%, temperature controlled at 30-35°C, initial pH: 2.4-2.9, end pH: 4.7-4.9, baking soda is used for alkali extraction, and the end temperature is 42-45°C.

5. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 1, characterized in that: In the neutralization process, a neutralizing tanning agent, sodium formate combined with baking soda is used, and the end point pH is controlled at 4.8-5.5 and the temperature is controlled at 30-40°C.

6. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 1, characterized in that: In the filling and retanning process, polymer fatliquor, polymer retanning agent and acrylic retanning agent are first added, and then acrylic retanning agents with large and medium molecular weights and neutral filling materials are added, and then amino resin is supplemented for retanning and filling.

7. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 1 is characterized in that: The filling and retanning process and the dyeing process adopt the same bath process; the fatliquor process adopts the separate bath process, with a liquid ratio of 50-200%, a temperature controlled at 45-48°C, and protein fillers, acrylic resin tanning agents, polymer fatliquors, synthetic oils, silicon-containing fatliquors, and lecithin are added for fatliquor.

8. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 2, characterized in that: The pH and bare skin adjustment process is specifically as follows: the amount of reagent used is determined by the percentage of the mass of the gray skin obtained in the peeling process, washing with water at 35°C until the bath pH is 7.4-7.9, then adjusting the liquid ratio to 150%, controlling the temperature at 30-36°C, and treating with 0.2-0.6% enzyme for 60-120 minutes.

9. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 3, characterized in that: The Tara tanning process is specifically as follows: the amount of reagents used is determined by the percentage of the mass of the gray leather obtained in the peeling process, 50-60% of water is added to the drum, 0.1-1% of an iron remover, 0.5-3% of a dispersant, and 6-12% of a Tara tannin tanning agent are added, and the drum is rotated at a temperature of 30-38°C for 120-180 minutes; 100-150% of water is added, and the drum is rotated at a temperature of 38-42°C for 30-120 minutes; formic acid is added to adjust the pH value of the bath liquid to 3.5-3.9; liquid is drained; 150-200% of water, 0.5-1% of oxalic acid, and 0.5-1% of formic acid are washed with water for 15-30 minutes; and liquid is drained.

10. The chrome-free tanning leather production process combining ecological vegetable tanning material and zeolite tanning agent according to claim 4, characterized in that: The zeolite tanning process is specifically as follows: the amount of reagent used is determined by the percentage of the mass of the gray leather obtained in the peeling process, 50-60% of water is added to the drum, the temperature in the drum is adjusted to 30-35°C, the pH of the bath liquid is adjusted to 2.4-2.9, 6-10% of zeolite tanning agent is added, and the drum is rotated for 90-180 minutes; the alkali is extracted with baking soda to a final pH of 4.7-4.9, 100-150% of water is added to adjust the temperature to 42-45°C, and the drum is rotated for 60-180 minutes; the liquid is drained; the water is washed and a mildew inhibitor is added; the liquid is drained, the drum is taken out, and the drum is mounted and left to stand.

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