阅读说明：本技术 一种全粒面牛皮自然摔纹沙发革及其制作方法 (Full-grain-surface cow leather natural grain-broken sofa leather and manufacturing method thereof ) 是由 杨义清 牛泽 位博宇 王春茂 孙传基 于 2021-10-22 设计创作，主要内容包括：本发明公开了一种全粒面牛皮自然摔纹沙发革及其制作方法,依次包括如下工艺步骤:牛蓝湿革组批、挤水、削匀、称重→整理1→回水→软化中和→填充加脂→整理2→泡水→染色加脂→整理3→喷底浆→喷面浆→喷光亮层→整理4→喷手感层→品检入库；本申请采用了四步整理的方法,并对湿态染整、涂饰工艺进行合理搭配,制得了粒面花纹自然柔和饱满、整身均匀一致有肉感、身骨柔软丰满有弹性的全粒面牛皮自然摔纹沙发革,解决了当前摔纹沙发革的生产加工过程中存在的花纹不一致、分布不均匀、手感扁薄、身骨硬挺等问题,且该方法整体流程简单易实现,操作方便简捷,生产成本低,所得全粒面牛皮自然摔纹沙发革得革率大、产品档次高,经济效益好。(The invention discloses full-grain cow leather natural pattern-falling sofa leather and a manufacturing method thereof, which sequentially comprises the following process steps of cow wet leather batching, water squeezing, even shaving, weighing → arrangement 1 → backwater → softening neutralization → filling and greasing → arrangement 2 → bubble water → dyeing and greasing → arrangement 3 → bottom pulp spraying → face pulp spraying → bright layer spraying → arrangement 4 → hand feeling layer spraying → product inspection and warehousing; the method adopts a four-step finishing method, and reasonably matches wet dyeing and finishing and coating processes to prepare the full-grain cowhide natural falling grain sofa leather with natural, soft and full grain patterns, uniform and consistent whole body, meat feeling, soft and plump body bones and elasticity, solves the problems of inconsistent patterns, uneven distribution, flat and thin hand feeling, stiff and stiff body bones and the like existing in the production and processing process of the current falling grain sofa leather, and has the advantages of simple and easy realization of the whole process, convenient and simple operation, low production cost, high leather yield of the obtained full-grain cowhide natural falling grain sofa leather, high product grade and good economic benefit.)

1. A manufacturing method of full-grain-surface cowhide natural pattern-cut sofa leather is characterized by sequentially comprising the following process steps of batching, water squeezing, shaving, weighing → arrangement 1 → backwater → softening neutralization → filling and greasing → arrangement 2 → bubble water → dyeing and greasing → arrangement 3 → bottom pulp spraying → face pulp spraying → bright layer spraying → arrangement 4 → hand feeling layer spraying → product inspection and warehousing.

2. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 1,

the finishing 1 procedure sequentially comprises a stretching plate → a pressing plate → vibration softening;

the finishing 2 process sequentially comprises stretching → a toggling → softening → vibrating → softening;

the finishing 3 process sequentially comprises stretching → vibrating;

the finishing 4 process sequentially comprises ironing → softening → stretching plate → vibrating softening.

3. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 2,

the temperature of the toggling plate in the finishing step 1 is 35-45 ℃, the toggling distance is 2-8cm, and the water content is controlled at 20-25%;

the temperature of the pressing plate in the finishing step 1 is 80-100 ℃, the pressure is 30-60kg, and the time is 1-3 s.

4. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 2,

the temperature of the toggling plate in the finishing step 2 is 40-50 ℃, the toggling distance is 6-14cm, and the water content is controlled at 6-10%;

the rewetting in the finishing step 2 is to spray water on the front side and the back side, and to stand for 8-12h, wherein the water content is controlled at 15-20%;

the milling time in the finishing 2 procedure is 10-30h, and the moisture content is controlled at 15-20%.

5. The method for manufacturing the full-grain-size cowhide natural grain-falling sofa leather according to claim 2, wherein the temperature of the toggling plate in the finishing step 3 is 40-50 ℃, the toggling distance is 6-14cm, and the moisture content is controlled to be 10-15%.

6. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 2,

the ironing temperature in the finishing 4 process is 100-130 ℃, and the pressure is 20-40 kg;

the time for softening in the finishing step 4 is 3-10h, and the water content is controlled to be 15-20%;

in the finishing step 4, the temperature of the toggling plate is 45-55 ℃, the toggling distance is 2-8cm, and the moisture content is controlled to be 10-15%.

7. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 1,

the water return process comprises the following specific steps: adding water 200-400% at 40-50 ℃, oxalic acid 1-3%, pickling oil 0.2-1%, rewetting agent 0.5-1.5% and degreasing agent 0.1-0.5% into the rotary drum, adjusting the pH value of the bath liquid to 2.5-3.0, and discharging liquid;

the softening and neutralizing steps are as follows: adding water of 200 percent and baking soda of 0.5 to 1.5 percent at the temperature of between 25 and 35 ℃ into the rotary drum according to the weight percentage of the wet blue leather obtained by shaving, and rotating for 20 to 60 minutes; adding 1-4% of acid softening enzyme preparation, and rotating; adding 1-4% of aldehyde tanning agent and 0.5-1.5% of phospholipid mixed fatting agent, and rotating; adding 1-4% of neutralizing and retanning agent and 1-4% of sodium formate, and rotating; adding 1-3% ammonium bicarbonate and 0.5-1.5% synthetic fat liquor, rotating, adjusting pH of the bath liquid to 6.5-7.5, and discharging liquid;

the filling and greasing method comprises the following specific steps: adding 30-100% of water with the temperature of 25-35 ℃, 1-3% of synthetic oil fatliquor, 1-2% of phospholipid mixed fatliquor and 1-2% of sulfited fatliquor into a rotary drum according to the weight percentage of the evenly shaved wet blue leather, and rotating; adding 3-6% of amino resin, 2-5% of plant tannin extract and 1-3% of dispersed tannin, and rotating; adding hot water of 100-; adding formic acid 2-4% for 3 times, each time at an interval of 20-30min, adjusting bath liquid pH to 3.4-3.6, and discharging liquid.

8. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 1,

the water soaking method comprises the following specific steps: adding water 300-600% at 45-55 ℃ and a rewetting agent 0.2-1.0% in the rotary drum according to the weight percentage of the evenly shaved wet blue leather, and rotating;

the dyeing and fat liquoring method comprises the following specific steps: adding water at 25-35 ℃ and 200% and baking soda at 0.5-1.5% into a rotary drum according to the weight percentage of the evenly-shaved wet blue leather, adjusting the pH value of the bath liquid to 4.2-4.5, and rotating; adding a dye and rotating; adding phospholipid mixed fatting agent 1-3%, synthetic oil fatting agent 1-3%, and lecithin fatting agent 1-3%, and rotating; adding formic acid 0.5-1.5% at intervals of 20-30min every time, adjusting bath liquid pH to 3.4-3.6, and discharging liquid.

9. The method for manufacturing full grain cow leather natural falling grain sofa leather according to claim 1,

the formula of the coating agent used by the bottom slurry is as follows: 100-200 parts of water, 100-200 parts of synthetic resin, 30-60 parts of water-based soft polyurethane resin, 20-40 parts of anion thermal foaming resin and 10-30 parts of pigment;

the finishing agent formula used by the flour paste is as follows: 100-200 parts of water, 20-40 parts of water-based soft polyurethane resin, 50-100 parts of anion masking primer, 50-100 parts of water-soluble comprehensive resin, 20-40 parts of permeable adhesive acrylic resin, 20-40 parts of particle acrylic resin, 20-40 parts of nonionic plate wax, 20-40 parts of matting filler, 20-40 parts of softening assistant and 10-30 parts of pigment;

the formula of the coating agent used for the bright layer is as follows: 100-200 parts of water, 100-200 parts of waterborne polyurethane bright resin, 2-10 parts of silicon-containing hand feeling agent and 2-5 parts of cross-linking agent;

the finishing agent formula used by the hand feeling layer is as follows: 100 portions of water and 200 portions of silicon-containing hand feeling agent, 5 portions to 15 portions of silicon-containing hand feeling agent and 10 portions to 50 portions of hand feeling wax.

10. A full grain cow leather natural grain sofa leather, characterized in that, it is made by the method of any claim 1-9.

Technical Field

The invention relates to the technical field of leather-making chemistry and engineering, in particular to full-grain-surface cowhide natural grain-broken sofa leather and a manufacturing method thereof.

Background

The cow leather natural grain-falling sofa leather is high-quality decorative furniture leather, has uniform, natural and attractive patterns, mellow hand feeling and high elasticity, and is particularly well pursued by the market for the cow leather natural grain-falling sofa leather with light coating on the whole grain surface. However, in recent years, due to the increasing demand of beef at home and abroad, the beef cattle has short and short growth cycle (basically less than 1.5 years), so that the fiber weaving in the beef cattle is loose, and the difference of the fiber structures among the hip, the back, the side abdomen and the head and neck becomes more obvious, so that the problems of unnatural patterns and uneven whole body are easy to occur in the processing process.

At present in the sofa leather course of working of falling soft, for the even uniformity that promotes the decorative pattern, often can adopt the method of scribbling of heavily pressing recoating, though can improve the homogeneity of grain face decorative pattern, but can lead to feeling flat thin, body bone is stiff, and ventilative nature and nature, soft sense reduce, reduce product grade. In recent years, the selling price of the grain-broken sofa leather produced by the heavy-load recoating method is reduced all the way to 8-10 yuan per square foot, the sofa leather is sold at the cost price, and the profit is basically zero. Therefore, the full-grain cattle hide natural falling grain sofa leather with the grain surface having the advantages of natural, soft and full grain patterns, soft and full body bones and elasticity is developed, the full-grain cattle hide natural falling grain sofa leather accords with the current fashion trend, and the full-grain cattle hide natural falling grain sofa leather has a wide market prospect.

Disclosure of Invention

The embodiment of the application solves the problems of inconsistent patterns, uneven distribution, flat and thin hand feeling, stiff and stiff body and bone and the like in the production and processing process of the conventional textured cow leather by providing the full-grain cow leather natural textured sofa leather and the manufacturing method thereof; the full grain face cowhide natural falling grain sofa leather has the advantages of high leather yield, high utilization rate, high product grade and good economic benefit.

The embodiment of the application provides a manufacturing method of full-grain face cow leather natural pattern-cut sofa leather, which sequentially comprises the following process steps of cow blue wet leather batching, water squeezing, even shaving, weighing → arrangement 1 → backwater → softening neutralization → filling and greasing → arrangement 2 → water soaking → dyeing and greasing → arrangement 3 → bottom pulp spraying → face pulp spraying → bright layer spraying → arrangement 4 → hand feeling layer spraying → quality inspection and warehousing.

Further, the finishing 1 procedure sequentially comprises a stretching plate → a pressing plate → vibration softening;

the finishing 2 process sequentially comprises stretching → a toggling → softening → vibrating → softening;

the finishing 3 process sequentially comprises stretching → vibrating;

the finishing 4 process sequentially comprises ironing → softening → stretching plate → vibrating softening.

Furthermore, the temperature of the toggling plate in the finishing step 1 is 35-45 ℃, the toggling distance is 2-8cm, and the water content is controlled to be 20-25%;

the temperature of the pressing plate in the finishing step 1 is 80-100 ℃, the pressure is 30-60kg, and the time is 1-3 s.

Furthermore, the temperature of the stretching plate in the finishing step 2 is 40-50 ℃, the stretching distance is 6-14cm, and the moisture content is controlled at 6-10%;

the rewetting in the finishing step 2 is to spray water on the front side and the back side, and to stand for 8-12h, wherein the water content is controlled at 15-20%;

the milling time in the finishing 2 procedure is 10-30h, and the moisture content is controlled at 15-20%.

Furthermore, the temperature of the stretching plate in the finishing step 3 is 40-50 ℃, the stretching distance is 6-14cm, and the moisture content is controlled at 10-15%.

Further, the ironing temperature in the finishing 4 process is 100-;

the time for softening in the finishing step 4 is 3-10h, and the water content is controlled to be 15-20%;

in the finishing step 4, the temperature of the toggling plate is 45-55 ℃, the toggling distance is 2-8cm, and the moisture content is controlled to be 10-15%.

Further, the water return process comprises the following specific steps: adding water 200-400% at 40-50 ℃, oxalic acid 1-3%, pickling oil 0.2-1%, rewetting agent 0.5-1.5% and degreasing agent 0.1-0.5% into the rotary drum, adjusting the pH value of the bath liquid to 2.5-3.0, and discharging liquid;

the softening and neutralizing steps are as follows: adding water of 200 percent and baking soda of 0.5 to 1.5 percent at the temperature of between 25 and 35 ℃ into the rotary drum according to the weight percentage of the wet blue leather obtained by shaving, and rotating for 20 to 60 minutes; adding 1-4% of acid softening enzyme preparation, and rotating; adding 1-4% of aldehyde tanning agent and 0.5-1.5% of phospholipid mixed fatting agent, and rotating; adding 1-4% of neutralizing and retanning agent and 1-4% of sodium formate, and rotating; adding 1-3% ammonium bicarbonate and 0.5-1.5% synthetic fat liquor, rotating, adjusting pH of the bath liquid to 6.5-7.5, and discharging liquid;

the filling and greasing method comprises the following specific steps: adding 30-100% of water with the temperature of 25-35 ℃, 1-3% of synthetic oil fatliquor, 1-2% of phospholipid mixed fatliquor and 1-2% of sulfited fatliquor into a rotary drum according to the weight percentage of the evenly shaved wet blue leather, and rotating; adding 3-6% of amino resin, 2-5% of plant tannin extract and 1-3% of dispersed tannin, and rotating; adding hot water of 100-; adding formic acid 2-4% for 3 times, each time at an interval of 20-30min, adjusting bath liquid pH to 3.4-3.6, and discharging liquid.

Further, the water soaking comprises the following specific steps: adding water 300-600% at 45-55 ℃ and a rewetting agent 0.2-1.0% in the rotary drum according to the weight percentage of the evenly shaved wet blue leather, and rotating;

the dyeing and fat liquoring method comprises the following specific steps: adding water at 25-35 ℃ and 200% and baking soda at 0.5-1.5% into a rotary drum according to the weight percentage of the evenly-shaved wet blue leather, adjusting the pH value of the bath liquid to 4.2-4.5, and rotating; adding a dye and rotating; adding phospholipid mixed fatting agent 1-3%, synthetic oil fatting agent 1-3%, and lecithin fatting agent 1-3%, and rotating; adding formic acid 0.5-1.5% at intervals of 20-30min every time, adjusting bath liquid pH to 3.4-3.6, and discharging liquid.

Further, the coating agent formula used by the primer slurry is as follows: 100-200 parts of water, 100-200 parts of synthetic resin, 30-60 parts of water-based soft polyurethane resin, 20-40 parts of anion thermal foaming resin and 10-30 parts of pigment;

the finishing agent formula used by the flour paste is as follows: 100-200 parts of water, 20-40 parts of water-based soft polyurethane resin, 50-100 parts of anion masking primer, 50-100 parts of water-soluble comprehensive resin, 20-40 parts of permeable adhesive acrylic resin, 20-40 parts of particle acrylic resin, 20-40 parts of nonionic plate wax, 20-40 parts of matting filler, 20-40 parts of softening assistant and 10-30 parts of pigment;

the formula of the coating agent used for the bright layer is as follows: 100-200 parts of water, 100-200 parts of waterborne polyurethane bright resin, 2-10 parts of silicon-containing hand feeling agent and 2-5 parts of cross-linking agent;

the finishing agent formula used by the hand feeling layer is as follows: 100 portions of water and 200 portions of silicon-containing hand feeling agent, 5 portions to 15 portions of silicon-containing hand feeling agent and 10 portions to 50 portions of hand feeling wax.

A full-grain-surface cowhide natural grain-broken sofa leather is prepared by the method disclosed by the application.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

1. this application has adopted 4 times arrangement process, and its effect is different respectively, specifically as follows:

firstly, a first finishing procedure (finishing 1) is carried out after the wet cow blue leather is shaved evenly and before water returns, collagen fibers inside and outside the leather are loosened by utilizing a toggling plate, a subsequent material permeation channel is opened, the leather yield is improved, the body of the cow blue leather is flat and uniform by utilizing the toggling plate, clear and flat fine guide lines can be obtained on the grain surface of the cow blue leather by matching with a pressing plate, natural and uniform grain surface patterns can be thrown out during subsequent finishing, the depth and the setting degree of the grain surface guide lines at different parts of the cow blue wet leather can be adjusted by adjusting the temperature, the pressure and the time of the pressing plate, and the position difference can be effectively reduced;

secondly, in the finishing step (finishing step 2), fibers in the leather and on the surface of the leather are opened by using a deep stretching plate (stretching distance is 6-14cm), so that the effects of increasing the leather yield and improving the uniformity of the grain pattern of the whole body are achieved, and the softness and fullness of the leather body and the natural plumpness of grain pattern are further improved by matching with high-strength breaking (10-30 h);

and thirdly, utilizing a deep stretching plate (stretching distance is 6-14cm) to further open fibers on the inner surface and the surface of the leather in the third finishing process (finishing 3), so that the effects of increasing the leather yield and improving the uniformity of the whole grain forming are achieved, the leather body is smooth and uniform, and the subsequent finishing is facilitated.

And fourthly, finishing 4 operation after finishing spraying the flour slurry in the coating process, depositing the coating slurry on the grain surface of the leather to form a film, which can affect the softness of the leather, the body and the hand feeling of the cotton bubbles, reduce the extension and the fullness of grain surface lines, and through the operations of breaking, toggling, vibrating, softening and the like in the fourth finishing process (finishing 4), the adverse effect can be effectively prevented, the leather yield can be further increased, the uniformity, the extension and the fullness of grain surface patterns can be improved, and the body and the natural and soft hand feeling of the soft cotton bubbles of the leather can be enhanced.

2. After finishing 1, the method adopts oxalic acid, pickling oil, a moisture returning agent and a degreasing agent to carry out water returning in a matched mode, can achieve multiple functions of degreasing, softening, lubricating, fiber dispersing and the like, and can wash away chromium ions which are not firmly combined in leather and are excessively combined on grain surfaces, so that the water returning effect which is uniform and consistent in whole body is achieved; then softening with acid softening enzyme to disperse collagen fiber in leather and release the binding site of subsequent material, and is matched with a plurality of neutralization materials such as ammonium bicarbonate, neutralization retanning agents and the like for neutralization, the ammonium bicarbonate has strong neutralization performance and foamability, can further fully loosen and separate collagen fibers while neutralizing, endow the cotton with meat bones, and the neutralizing and retanning agent has soft and uniform neutralizing performance and deep penetration, can ensure that the inside and the outside of the leather have uniform neutralizing effect, and the aldehyde tanning agent and the phospholipid are added before the neutralization material is added for mixing and fatting, so that on one hand, the penetration and uniform distribution of the neutralization material in the leather can be promoted, the uniform uniformity of the neutralization inside and outside the leather is further improved, on the other hand, the collagen fiber can be lubricated and protected, and the damage to the fiber in the leather possibly caused by the strong foamability of the ammonium bicarbonate can be prevented in advance, so that the uniform softening and neutralizing effects can be obtained.

3. In the filling and greasing process, amino resin with selective filling performance is adopted to match with plant tannin extract with excellent filling performance as main filler, so that the fullness, compactness, plumpness and elasticity of the leather are improved, the leather is endowed with uniform and consistent body bones and handfeel, the potential difference is reduced, and the plant tannin extract can increase the grain surface plasticity of the leather, thereby being beneficial to obtaining uniform and clear grain surface texture effect in the follow-up process; filling and greasing are carried out in one bath, the greasing agent is added twice before and after the filling, so that the body bone of the leather is softer and fleshy, and various greasing agents are adopted to cooperate with the greasing to lubricate the fibers in the leather from inside to outside in an all-round way, so that the leather is endowed with soft and oily hand feeling and excellent physical and mechanical properties.

4. After filling and greasing are completed, the leather body leather property is also preliminarily shaped, fibers in the leather are fully lubricated and loosened, the leather is finished 2, then bubble water is returned and greasing dyeing is performed, and the fibers in the leather and the leather surface are further lubricated and loosened through a moisture returning agent and a greasing agent, so that the leather has better and more smooth grain surface, better hand feeling, fullness and softness, and better body and bone, and the cotton bubbles have meat feeling; finishing 3, wherein the water-based light finishing is adopted for finishing, so that the VOC pollution is less, the air permeability of the leather is good, the utilization rate is high, and the hand feeling of the leather is soft and moist; and finishing 4 after finishing spraying the surface paste in the coating process.

5. The method adopts a four-step finishing method, and reasonably matches wet dyeing and finishing and coating processes to prepare the full-grain cowhide natural grain sofa leather with natural, soft and full grain patterns, uniform and consistent whole body, meat feeling, soft and plump body bones and elasticity, solves the problems of inconsistent patterns, uneven distribution, flat and thin hand feeling, stiff and stiff body bones and the like existing in the production and processing process of the current grain sofa leather, and has the advantages of simple and easy realization of the whole process, convenient and simple operation, strong practicability, less used chemical materials, low production cost, high leather yield of the obtained full-grain cowhide natural grain sofa leather, high product grade and good economic benefit.

Detailed Description

In order to better understand the technical solutions, the technical solutions will be described in detail with reference to the description and the specific embodiments.

A method for manufacturing full-grain-surface cowhide natural grain-broken sofa leather comprises the following process steps:

step 1, batching, wringing, shaving and weighing the cattle blue wet leather: classifying the wet blue leather according to the principle that the leather source is consistent in producing area, size, thickness and grade to form a production batch, and sequentially carrying out water squeezing, leather splitting, shaving and weighing; the dosage of the reagent used in the subsequent procedures is calculated according to the weight percentage of the shaved wet blue leather obtained by weighing (namely the mass of the shaved wet blue leather is 100 percent, and when the mass of the shaved wet blue leather is 100kg, 2 percent of oxalic acid is 2 kg);

step 2, finishing 1: sequentially carrying out toggling, pressing and vibration softening on the uniformly weighed cattle blue wet leather, wherein the temperature of a toggling plate is 40 ℃, the toggling distance is 4cm, the moisture content is controlled to be 20-22%, the temperature of a pressing plate is 90 ℃, the pressure is 45kg, and the time is 2 s;

step 3, water returning: adding water 300% at 45 deg.C, oxalic acid 2% (conventional industrial oxalic acid), pickling oil 0.8% (B1 of Toeplier chemical company), humectant 1% (FP of Simma chemical company) and degreasing agent 0.3% (SAF of Delaii chemical company) into the rotary drum, rotating for 180min, and discharging liquid when the pH of the bath liquid is 2.7;

step 4, softening and neutralizing, namely adding 150% of water with the temperature of 30 ℃ and 1% of baking soda (conventional industrial baking soda) into a rotary drum, and rotating for 40 min; adding 3% acid softening enzyme preparation (TN of Deshel chemical company), and rotating for 180 min; adding 2% aldehyde tanning agent (PF of Sima chemical company) and 1% phospholipid mixed fatting agent (OSL of Toeplier chemical company), and rotating for 60 min; adding 3% of neutralizing and retanning agent (NG of Derui chemical company) and 3% of sodium formate (conventional industrial sodium formate), and rotating for 45 min; adding 2% ammonium bicarbonate and 1% synthetic fat liquor (SLG of Derui chemical company), rotating for 120-180min, adjusting the pH value of the bath liquid to 6.5-7.5, and discharging the liquid;

step 5, filling and greasing: adding 30 deg.C water 60%, 2% synthetic oil fatting agent (94S of Sima chemical company), 1% phospholipid mixed fatting agent, and 1% sulfited fatting agent (MIR-90 of Italy chemical company) into the rotary drum, and rotating for 40 min; adding 5% amino resin (DLF of BASF chemical), 4% vegetable tannin extract (ATO of Uygur chemical), and 2% dispersed tannin (T-M of BASF chemical), and rotating for 90 min; adding 60 deg.C hot water 200%, phospholipid mixed fat liquor 4%, synthetic oil fat liquor 4%, lecithin fat liquor 3% (BA of Sima chemical company), and sulfited fat liquor 2%, and rotating for 90 min; adding 3% of formic acid for 3 times, wherein the interval of each time is 30min, the pH value of the end-point bath liquid is 3.6, and discharging the liquid;

step 6, finishing 2: sequentially stretching, toggling, rewetting, vibrating and softening the filled and fatliquored crust leather, wherein the temperature of the toggling is 45 ℃, the toggling distance is 12cm, the moisture content is controlled to be 8-10%, the rewetting is that water is sprayed on the front surface and the back surface, standing is carried out for 10h, the moisture content is controlled to be 15-17%, the time for softening is 25h, and the moisture content is controlled to be 17-19%;

step 7, soaking in water: adding water 500% at 50 deg.C and 0.5% of moisture regaining agent into the rotary drum, and rotating for 240 min;

step 8, dyeing and fat liquoring: adding 30 deg.C water 200% and 1% sodium bicarbonate into the rotary drum, adjusting bath liquid pH to 4.3, and rotating for 40 min; adding dye, and rotating for 60 min; adding phospholipid mixed fat liquor 1%, synthetic oil fat liquor 1%, and lecithin fat liquor 2%, and rotating for 60 min; adding 1% of formic acid by 2, separating for 20min each time, controlling the pH of the final bath liquid to be 3.5, and discharging the liquid;

step 9, finishing 3: sequentially stretching, toggling and vibrating for softening the dyed and fatliquored crust leather, wherein the temperature of the toggling is 45 ℃, the toggling distance is 10cm, and the moisture content is controlled to be 13-15%;

step 10, spraying bottom slurry: carrying out bottom pulp spraying operation on the crust leather finished with the finishing 3 on a pulp spraying machine for 2 times, wherein the formula of the bottom pulp coating agent comprises 150 parts of water, 150 parts of synthetic resin (800 of the Bakman chemical company), 50 parts of water-based soft polyurethane resin (817 of the Bakman chemical company), 30 parts of anion thermal foaming resin (FH 20 of the CBS chemical company) and 20 parts of pigment;

step 11, spraying surface paste: the crust leather which finishes bottom spraying is sprayed for 2 times on a pulp spraying machine, and the formula of the used face-sizing coating agent is 180 parts of water, 30 parts of water-based soft polyurethane resin, 90 parts of anion shading bottom sealing agent (NC of Steyr chemical company), 90 parts of water-soluble comprehensive resin (2349 of Steyr chemical company), 30 parts of permeable adhesive acrylic resin (776 of Steyr chemical company), 30 parts of particle acrylic resin (807 of Buckman chemical company), 30 parts of nonionic veneer wax (Fi-50 of Steyr chemical company), 30 parts of matting filler (FD of Potentilla chemical company), 30 parts of soft auxiliary agent (S-C of Langsheng chemical company) and 20 parts of pigment;

step 12, spraying a bright layer: spraying a bright layer on the crust leather subjected to surface paste spraying on a pulp spraying machine for 1 time, wherein the formula of the bright layer coating agent comprises 100 parts of water, 100 parts of waterborne polyurethane bright resin (2003 of Toddar chemical company), 5 parts of silicon-containing hand feeling agent (SW 68 of Toddar chemical company) and 2 parts of cross-linking agent (AKU of Steyr chemical company);

step 13, finishing 4: sequentially ironing, breaking, toggling and vibrating the crust leather which is finished with the bright layer, wherein the ironing temperature is 110 ℃, the pressure is 30kg, the breaking time is 6h, the moisture content is controlled at 16-18%, the toggling temperature is 50 ℃, the toggling distance is 5cm, and the moisture content is controlled at 12-14%;

step 14, spraying a hand feeling layer: spraying the hand feeling layer on the crust leather which is finished with the finishing 4 on a spraying machine for 1 time, wherein the formula of the coating agent used by the hand feeling layer comprises 100 parts of water, 10 parts of silicon-containing hand feeling agent and 30 parts of hand feeling wax (1916 of Todda chemical company);

and step 15, quality inspection and warehousing, namely after the hand feeling layer spraying is finished, obtaining full-grain-surface cowhide natural grain-falling sofa leather, performing quality inspection, and warehousing and delivering goods.

The leather obtained by the manufacturing method of the full grain cow leather natural grain-throwing sofa leather has the advantages of natural, soft and full grain patterns, uniform and consistent whole body, meat feeling, soft, plump and elastic body bones, good air permeability and water vapor permeability, high product grade, high leather yield and high utilization rate.

The above description is only an embodiment utilizing the technical content of the present disclosure, and any modification and variation made by those skilled in the art can be covered by the claims of the present disclosure, and not limited to the embodiments disclosed.