Preparation process of ultrathin microfiber leather for vehicles

Abstract

The invention discloses a preparation method of ultrathin microfiber leather for a vehicle. The preparation method of the ultrathin microfiber leather for the vehicle comprises the following preparation steps: S1, preparing sea-island fibers; s2, preparing a superfine fiber non-woven fabric; s3, production of base cloth; s4, preparing an unsplit semi-finished product from the superfine fiber non-woven fabric through a wet-process water-based polyurethane process; s6, the split semi-finished product is dried, shaped and rolled with wind; s7, performing hot kneading on the kneaded semi-finished product through a hot kneading machine; s8, after hot rolling, leather buffing and double-sided buffing are carried out twice; and S9, veneering the semi-finished product subjected to leather buffing with solvent-free polyurethane, so as to manufacture the ultrathin microfiber leather. The invention has the following beneficial effects: 1) the thickness can reach 0.6-0.9 mm (as shown in figure 7 / 11), which is 19%-50% thinner than 1.1-1.2 mm of the normal commercially available fabric; and 2) the thin and soft hand feeling and touch feeling can be considered, and the comfort performance of the interior material is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of leather, and in particular to a preparation process of ultra-thin ultra-fiber leather for vehicles. Background Art

[0002] Automotive interior microfiber leather, full name automotive microfiber reinforced leather, is a new type of synthetic material. It is made of microfiber as the base material through a special processing technology. Microfiber leather has excellent wear resistance, cold resistance and good hand feel, and is widely used in the field of automotive interiors, such as seats, steering wheels, dashboards and other parts. Performance advantages: Compared with traditional natural leather, microfiber leather has better wear resistance, chemical corrosion resistance and longer service life. Good environmental protection: Animal leather is not used in the production process of microfiber leather, which conforms to the concept of environmental protection. Flexible design: Microfiber leather products of various colors, textures and styles can be achieved by adjusting the production process and surface treatment methods.

[0003] Defects and shortcomings of the existing technology:

[0004] 1. Market demand growth: Consumers' demand for lightweight car interiors has driven the demand for ultra-thin and ultra-light interior fabrics. The current conventional microfiber leather interior materials cannot meet the ultra-thin and ultra-light lightweight market customer requirements.

[0005] 2. Insufficient breathability: Although the breathability of microfiber leather is better than some other synthetic materials, it is still inferior to natural leather. In high temperature environments, the insufficient breathability of microfiber leather seats may cause passengers to feel stuffy and uncomfortable.

[0006] 3. Comfort needs to be improved: Some microfiber leather products still have a certain gap with natural leather in terms of feel, softness and elasticity, which affects the riding comfort of passengers.

[0007] 4. For thin microfiber leather (thickness 0.6mm-0.9mm), the existing process usually adopts the splitting process, that is, the leather base cloth is split into two pieces by a splitting machine, such as splitting a 2.0mm thick microfiber leather base into 0.5mm and 1.5mm thick microfiber leather base. The microfiber leather base that has been split has its internal joints formed by needle puncture destroyed. Therefore, the thin microfiber leather base produced by the splitting process has relatively low physical properties such as tensile strength and tear strength, and it is difficult to produce ultra-thin microfiber leather series products with a thickness of 0.60-0.90mm that meet the physical property requirements.

[0008] To sum up, in order to solve the problems of the prior art, the ultra-thin ultra-fiber leather for vehicles prepared by the present invention can not only meet the lightweight requirements of the market demand, but also indirectly improve the battery life of new energy vehicles, while also reducing costs and improving breathability and comfort. Summary of the invention

[0009] The purpose of the present invention is to provide a preparation process of ultra-thin microfiber leather for vehicles. The ultra-thin microfiber leather for vehicles prepared by the method not only has a thickness of 0.6-0.9mm (commercially available fabrics are 1.1-1.2mm, thinned by 19%-50%), but also has improved air permeability and comfort, and can also take into account the thin and soft feel and touch, effectively improving the comfort performance of interior materials.

[0010] To achieve the above purpose, the following technical solutions are used:

[0011] A method for preparing ultra-thin ultra-fine leather for vehicles, the method comprising the following preparation steps:

[0012] S1 prepares the sea-island fiber, melts and mixes the polyamide slices and the polyethylene slices, and prepares the nylon-blended sea-island fiber through a spinning process;

[0013] S2 is used to prepare ultrafine fiber nonwoven fabrics, and nylon blended sea island fibers are used to prepare ultrafine fiber nonwoven fabrics through a needle punching process;

[0014] S3 weighs, combs and shapes the ultrafine fiber non-woven fabric to achieve stable thickness and weight. The thickness is 0.5-0.8mm, and the production of the base fabric is completed.

[0015] S4: The ultrafine fiber non-woven fabric is wet impregnated with water-based polyurethane to obtain an unopened semi-finished product (the coating thickness is 0.2 mm, and the water-based polyurethane resin is rolled into the non-woven fabric by rollers, and the gap between each pair of rollers is (cloth thickness - 0.2 mm) to (cloth thickness - 0.3 mm););

[0016] S5: The semi-finished product is immersed in hot water at a temperature of 110-120°C for 90-150 minutes, and after fiber opening treatment, it is washed with water at 90-110°C for 30 minutes, and washed twice to obtain a semi-finished product after fiber opening;

[0017] S6 dries, shapes and air-kneads the semi-finished fiber products;

[0018] S7 passes the semi-finished product after kneading through a hot kneading machine for further hot kneading;

[0019] S8 is then polished after hot kneading, with both sides polished twice;

[0020] S9 uses solvent-free polyurethane veneer to laminate the semi-finished leather after grinding to produce ultra-thin microfiber leather.

[0021] As a further improvement, in S1, the weight ratio of the polyamide slices to the polyethylene slices is 35-45:65-75.

[0022] As a further improvement, in S2, in the needle punching process, the average gram weight is 400 g / m 2 - 460 g / m 2 , the number of laying webs is 25 - 40 layers, and the linear speed of the non-woven fabric production equipment is 3 - 5 m / min.

[0023] As a further improvement, in S3, the shaping process of the ultrafine fiber non-woven fabric is specifically as follows:

[0024] S31 Dry the ultrafine fiber non-woven fabric through a 4-stage oven with different temperature gradients. The temperatures are set at 90°C, 100°C, 120°C, and 145°C respectively, and the vehicle speed is 10 - 12 m / min;

[0025] S32 After heat setting, the ultrafine fiber non-woven fabric can be cooled by 6 cold fans at the end of the setting and drying line.

[0026] As a further improvement, in S4, the specific preparation steps of the fibrillated semi-finished product are as follows:

[0027] Immerse the semi-finished product in hot water at a temperature of 110 - 120°C for 90 - 150 min for fibrillating treatment, and then wash it with water at 90 - 110°C for 30 min, twice, to obtain the fibrillated semi-finished product.

[0028] As a further improvement, in S4,

[0029] The coating thickness is 0.2 mm. Roll the waterborne polyurethane resin into the non-woven fabric through a rolling mill. The gap between each pair of rolling mills is: fabric thickness - 0.2 mm to fabric thickness - 0.3 mm.

[0030] As a further improvement, in S4, in the wet impregnation process of waterborne polyurethane, the impregnation formulation is:

[0031] Mix the waterborne polyurethane - model Mill W01, leveling agent, defoaming agent, and softener in a weight ratio of 25:0.3:0.02:1.2 for 100 parts, and then add them to the formulation tank together with the pigment paste and stir evenly for 90 - 120 minutes to obtain the required impregnation formulation.

[0032] As a further improvement, the solid content of the waterborne polyurethane resin working solution is 18% - 22%, and the viscosity is 7000 cps - 8000 cps;

[0033] The leveling agent is any one of Tech-2550 and Degussa TEGO-410;

[0034] The defoaming agent is any one of PX-3841 and MSD-151A;

[0035] The softener is any one of S-301 and Dinamica.

[0036] As a further improvement, the wet impregnation process of waterborne polyurethane is carried out at a high temperature for solidification, and the temperature range is 40-45°C;

[0037] During the needling process, the needle density is 2460-3000 C / cm 2 .

[0038] As a further improvement, the density range of the shaped ultrafine fiber non-woven fabric is 0.28-0.32.

[0039] An anti-collapse automotive interior genuine leather of the present invention has the following beneficial effects:

[0040] 1) Soft and comfortable hand feeling: It has a soft texture, a delicate surface touch, giving a feeling close to natural leather, making the driver more comfortable during driving and reducing the fatigue caused by long-term driving.

[0041] 2) It meets the lightweight requirements needed by market customers. The thickness can be achieved at 0.6-0.9 mm, which is 19%-50% thinner than the 1.1-1.2 mm of normal commercially available fabrics, significantly reducing the weight and thickness without reducing the quality requirements.

[0042] 3) The air permeability and comfort are also improved. As the thickness decreases, the air permeability increases inversely. At the same time, the thin and soft hand feeling and touch also greatly enhance the comfort performance of the interior material.

[0043] 4) It is easy to operate. Compared with traditional or current manufacturing processes, it does not add harsh conditions, complex process routes or environmental requirements, and belongs to a process preparation route that is easy to operate and has a small increase in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is the front view of Comparative Example 1 in the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention;

[0045] Figure 2 It is the side view of Comparative Example 2 in the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention;

[0046] Figure 3 It is the front view of Comparative Example 3 in the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention;

[0047] Figure 4 It is the side view of Comparative Example 4 in the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention;

[0048] Figure 5In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the side measurement diagram of the thickness of the conventional ultra-fine leather in Comparative Example 1;

[0049] Figure 6 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the side measurement diagram of the thickness of the conventional ultra-fine leather in Comparative Example 2;

[0050] Figure 7 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the front view of the ultra-thin and ultra-fine leather in Example 1;

[0051] Figure 8 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the front view of the ultra-thin and ultra-fine leather in Example 2;

[0052] Figure 9 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the front view of the ultra-thin and ultra-fine leather in Example 3;

[0053] Figure 10 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the front view of the ultra-thin and ultra-fine leather in Example 4;

[0054] Figure 11 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the side measurement diagram of the thickness of the ultra-thin and ultra-fine leather in Example 1;

[0055] Figure 12 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the side measurement diagram of the thickness of the ultra-thin and ultra-fine leather in Example 2;

[0056] Figure 13 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the side measurement diagram of the thickness of the ultra-thin and ultra-fine leather in Example 3;

[0057] Figure 14 In the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention, it is the side measurement diagram of the thickness of the ultra-thin and ultra-fine leather in Example 4;

[0058] Figure 15 It is the process flow diagram of the preparation process of the ultra-thin and ultra-fine leather for vehicles of the present invention. Detailed implementation manners

[0059] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments and the accompanying drawings:

[0060] Example 1

[0061] ① Mix nylon chips and polyethylene chips with a weight ratio of the chips being 35 - 45:65 - 75, then conduct high-temperature melting and mixing (260 - 290 °C), and obtain sea-island fibers blended with polyamide through a spinning process;

[0062] ② The prepared polyamide blended sea-island fiber is made into ultra-fine fiber non-woven fabric through the needling process (the average gram weight produced by the needling process is 400 g / m 2 -460 g / m 2 , the number of laying layers is 25 - 40 layers, and the linear speed of the non-woven fabric production equipment is 3 - 5 m / min.);

[0063] ③ The thickness and gram weight of the ultra-fine fiber non-woven fabric are stabilized through weighing, carding, and shaping (the shaping thickness is controlled at 0.5 - 0.8 mm), and the production of the base fabric can be completed;

[0064] ④ The ultra-fine fiber non-woven fabric is made into an unopened semi-finished product through the wet impregnation process of waterborne polyurethane (the coating thickness is 0.2 mm, and the waterborne polyurethane resin is rolled into the non-woven fabric through a roller, and the gap between each pair of rollers is (fabric thickness - 0.2 mm) - (fabric thickness - 0.3 mm)); the impregnation formulation is specifically to mix waterborne polyurethane (controlling the solid content of the waterborne polyurethane resin working fluid to be 18% - 22%, and the viscosity to be 7000 cps - 8000 cps), supplemented with a leveling agent, an antifoaming agent, and a softening agent in a weight ratio of 25:0.3:0.02:1.2, and then add an appropriate amount of pigment paste to the formulation bucket and stir evenly for 90 - 120 minutes to obtain it.

[0065] ⑤ The semi-finished product is immersed in hot water at a temperature of 110 - 120 °C for 90 - 150 min for fiber opening treatment, and then washed with water at 90 - 110 °C for 30 min, and washed twice to obtain the fiber-opened semi-finished product;

[0066] ⑥ The fiber-opened semi-finished product is dried, shaped, and air-rubbed; (when drying, the temperatures are set at 90 °C, 100 °C, 120 °C, and 145 °C respectively, the vehicle speed is 10 - 12 m / min, and the ultra-fine fiber non-woven fabric after heat setting can be cooled by 6 cold fans at the end of the setting and drying line)

[0067] ⑦ The semi-finished product after rubbing is hot-rubbed again through a hot-rubbing machine (the hot-rubbing temperatures are set at 110 °C, 120 °C, 130 °C, and 140 °C respectively, and the vehicle speed is 10 - 12 m / min);

[0068] ⑧ After hot-rubbing, leather grinding is carried out, and it is ground twice on both sides (the sandpaper used is 280-mesh sandpaper)

[0069] ⑨ The semi-finished product after leather grinding is laminated with solvent-free polyurethane to manufacture an ultra-thin superfine leather;

[0070] More specifically, the key parameters in this embodiment are as follows:

[0071] The weight ratio of the polyamide (such as nylon) chips to the polyethylene chips is: 35 - 45:65 - 75;

[0072] The sizing of the ultrafine fiber non-woven fabric specifically involves drying the ultrafine fiber non-woven fabric in a 4-stage oven with different temperature gradients. The temperatures are set at 90°C, 100°C, 120°C, and 145°C respectively, the linear speed is 10 - 12 m / min, and the heat-set ultrafine fiber non-woven fabric can be cooled by 6 cold fans at the end of the sizing and drying line;

[0073] The specific preparation steps of the fibrillated semi-finished product are as follows: Immerse the semi-finished product in hot water at 110 - 120°C for 90 - 150 minutes for fibrillating treatment, then wash it with water at 90 - 110°C for 30 minutes, and wash it twice to obtain the fibrillated semi-finished product.

[0074] In the wet impregnation process of waterborne polyurethane, the impregnation formulation specifically involves mixing waterborne polyurethane (controlling the solid content of the waterborne polyurethane resin working solution to be 18% - 22% and the viscosity to be 7000 cps - 8000 cps;), a leveling agent, an antifoaming agent, and a softening agent in a weight ratio of 100 parts: 25: 0.3: 0.02: 1.2, and then adding an appropriate amount of pigment paste to the mixing tank and stirring evenly for 90 - 120 minutes to obtain it.

[0075] The wet impregnation process of waterborne polyurethane uses a high temperature for solidification, and the specific temperature range is 40 - 45°C.

[0076] During the needling process, the needle density is 2460 - 3000 C / cm 2 。

[0077] The density range of the sized ultrafine fiber non-woven fabric is 0.28 - 0.32.

[0078] Example 2

[0079] ① Mix nylon chips and polyethylene chips with a slice weight ratio of 35 - 45: 65 - 75, then perform high-temperature melting and mixing (260 - 290°C), and obtain polyamide blended sea-island fibers through a spinning process;

[0080] ② Produce ultrafine fiber non-woven fabric from the prepared polyamide blended sea-island fibers through a needling process (the average gram weight produced by the needling process is 400 g / m 2 -460 g / m 2 , the number of laying layers is 25 - 40 layers, and the linear speed of the non-woven fabric production equipment is 3 - 5 m / min.).

[0081] ③ Stabilize the thickness and gram weight of the ultrafine fiber non-woven fabric through weighing, carding, and sizing (the sizing thickness is controlled at 0.5 - 0.8 mm), and the production and manufacturing of the base fabric can be completed;

[0082] ④ The microfiber non-woven fabric is wet-impregnated with water-based polyurethane to obtain an unopened semi-finished product; (the coating thickness is 0.2mm, and the water-based polyurethane resin is rolled into the non-woven fabric by rollers, and the gap between each pair of rollers is (cloth thickness - 0.2mm) ~ (cloth thickness - 0.3mm);); the impregnation ingredients are specifically water-based polyurethane (the solid content of the water-based polyurethane resin working liquid is controlled to be 25%-30%, and the viscosity is 9000cps-10000cps;), supplemented with leveling agent, defoaming agent, and softener in a weight ratio of 25:0.3:0.02:1.2, and then added to the mixing barrel together with an appropriate amount of pigment paste and stirred evenly, and stirred for 90-120 minutes to obtain.

[0083] ⑤ Soak the semi-finished product in hot water at a temperature of 110-120°C for 90-150 minutes, perform fiber opening treatment, and then wash it with water at 90-110°C for 30 minutes, wash it twice, and obtain the semi-finished product after fiber opening;

[0084] ⑥Dry, shape and air-knead the semi-finished fiber products;

[0085] (During drying, the temperature is set at 90℃, 100℃, 120℃, and 145℃ respectively, and the speed is 10-12m / min. The heat-set microfiber non-woven fabric can be cooled by 6 cold fans at the end of the setting drying line)

[0086] ⑦ Pass the semi-finished product after kneading through the hot kneading machine for further hot kneading (the hot kneading temperatures are set at 110℃, 120℃, 130℃, 140℃, and the speed is 10-12m / min);

[0087] ⑧ After hot kneading, grind the leather twice on both sides, using 280-grit sandpaper;

[0088] ⑨Use solvent-free polyurethane veneer to produce ultra-thin microfiber leather;

[0089] During the implementation of Example 2, if the impregnation process is carried out according to the conventional impregnation formula, stickiness and coagulation will occur. The reason is that after the ultrafine fiber non-woven fabric is tightly woven, the high solid content and viscous density cannot be quickly rolled into the interior. After adjusting to reduce the solid content and viscosity, the results are greatly improved.

[0090] Example 3

[0091] ① Slice nylon and polyethylene at a weight ratio of 35-45:65-75, then melt mix at high temperature (260-290°C), and obtain nylon-blended sea-island fibers through a spinning process;

[0092] ② The prepared nylon blended sea island fiber is produced into a superfine fiber nonwoven fabric through a needle punching process (the average weight of the needle punching process is 400g / m2 -460g / m 2 , the number of ply layers is 25-40 and the line speed of non-woven fabric production equipment is 3-5m / min. );

[0093] ③ The ultrafine fiber non-woven fabric is weighed, combed and shaped to achieve a stable thickness and weight (the shaping thickness is controlled at 0.5-0.8mm), and the production of the base fabric can be completed;

[0094] ④ The microfiber non-woven fabric is wet-impregnated with water-based polyurethane to obtain an unopened semi-finished product (the coating thickness is 0.2mm, and the water-based polyurethane resin is rolled into the non-woven fabric by a roller, and the gap between each pair of rollers is (cloth thickness - 0.2mm) ~ (cloth thickness - 0.3mm)). The impregnation ingredients are specifically water-based polyurethane (the solid content of the water-based polyurethane resin working fluid is controlled to be 18%-22%, and the viscosity is 7000cps-8000cps;), supplemented with a leveling agent, a defoaming agent, and a softener in a weight ratio of 25:0.3:0.02:0.6, and then added to a mixing barrel together with an appropriate amount of pigment paste and stirred evenly for 90-120 minutes to obtain the product.

[0095] ⑤ Soak the semi-finished product in hot water at a temperature of 110-120°C for 90-150 minutes, perform fiber opening treatment, and then wash it with water at 90-110°C for 30 minutes, wash it twice, and obtain the semi-finished product after fiber opening;

[0096] ⑥Dry, shape and air-knead the semi-finished products; (the drying temperature is set at 90℃, 100℃, 120℃ and 145℃ respectively, and the speed is 10-12m / min. The heat-shaped ultrafine fiber non-woven fabric can be cooled by 6 cold fans at the end of the shaping and drying line)

[0097] ⑦ Pass the semi-finished product after kneading through the hot kneading machine for further hot kneading (the hot kneading temperatures are set at 110℃, 120℃, 130℃, 140℃, and the speed is 10-12m / min);

[0098] ⑧ After hot kneading, grind the leather twice on both sides (use 280 mesh sandpaper)

[0099] ⑨Use solvent-free polyurethane veneer to produce ultra-thin microfiber leather;

[0100] This embodiment 3

[0101] The main changes are as follows: The weight ratio of the leveling agent to the softening agent is adjusted from 0.3:1.2 to 0.6:0.6. It is found that during the impregnation process, the liquid cannot be fully and evenly rolled into the microfiber non-woven fabric. At this time, the leveling effect of the formula is not good, and after air kneading, compared with other embodiments, the softness and fullness also decrease. Therefore, it is necessary to improve the leveling agent and the softening agent.

[0102] Example 4

[0103] ① Nylon chips and polyethylene chips are taken, and the weight ratio of the chips is 35 - 45:65 - 75. Then, they are subjected to high-temperature melting and mixing (260 - 290 °C), and sea-island fibers of polyamide blend are obtained through a spinning process.

[0104] ② The prepared polyamide blend sea-island fibers are made into microfiber non-woven fabric through a needling process (the average gram weight produced by the needling process is 400 g / m 2 -460 g / m 2 , the number of laying layers is 25 - 40 layers, and the linear speed of the non-woven fabric production equipment is 3 - 5 m / min.).

[0105] ③ The thickness and gram weight of the microfiber non-woven fabric are stabilized through weighing, carding, and shaping (the shaping thickness is controlled at 0.5 - 0.8 mm), and thus the production and manufacturing of the base fabric can be completed.

[0106] ④ The microfiber non-woven fabric is made into an unopened semi-finished product through a wet impregnation process with waterborne polyurethane (the coating thickness is 0.2 mm, and the waterborne polyurethane resin is rolled into the non-woven fabric through a roll. The gap between each pair of rolls is (fabric thickness - 0.2 mm) to (fabric thickness - 0.3 mm)); specifically, the impregnation formulation is to mix waterborne polyurethane (the solid content of the waterborne polyurethane resin working solution is controlled at 18% - 22%, and the viscosity is 7000 cps - 8000 cps), supplemented with a leveling agent, an antifoaming agent, and a softening agent in a weight ratio of 25:0.3:0.02:1.2, and then add an appropriate amount of pigment paste to the mixing tank and stir evenly for 90 - 120 minutes to obtain it.

[0107] ⑤ The semi-finished product is immersed in hot water at a temperature of 110 - 120 °C for 90 - 150 min for fiber opening treatment, and then washed with water at 90 - 110 °C for 30 min, twice, to obtain the fiber-opened semi-finished product.

[0108] ⑥ The fiber-opened semi-finished product is dried, shaped, and air kneaded; (when drying, the temperatures are set at 90 °C, 100 °C, 120 °C, and 145 °C respectively, the vehicle speed is 10 - 12 m / min, and the microfiber non-woven fabric after heat setting can be cooled by 6 cold fans at the end of the setting and drying line)

[0109] ⑦ Pass the semi-finished product after kneading through the hot kneading machine for further hot kneading (the hot kneading temperatures are set at 110℃, 120℃, 130℃, 140℃, and the speed is 10-12m / min);

[0110] ⑧ After hot kneading, grind the leather, double-sided grinding once (use 200-grit sandpaper)

[0111] ⑨Use solvent-free polyurethane veneer to produce ultra-thin microfiber leather;

[0112] This embodiment 4 is mainly to improve the test of leather grinding after hot kneading. When the number of leather grinding and the fineness of sandpaper are reduced, it is found that there are still unevenness on the surface of the substrate, and if veneer is continued, the veneer process cannot cover up the defects, and small bubbles are easily generated, affecting the appearance and performance.

[0113] According to the comparative examples, we obtained 4 embodiments

[0114] Table 1 Comparison table of key process parameters of Examples 1 to 4

[0115]

[0116] Table 1 Comparison table of key process parameters of Examples 1 to 4

[0117]

[0118] Comparative Example 1

[0119] The conventional process is to melt-spin nylon slices and polyethylene slices at a weight ratio of 50-60:75-85, and then produce ultra-fine fiber non-woven fabrics through a needle punching process (the average weight of the needle punching process is 320g / m 2 -380g / m 2 , the number of mesh layers is 15-20 and the line speed of non-woven fabric production equipment is 8-10m / min. ), if we continue to do this, if the subsequent process remains unchanged, the tearing performance and elongation will be insufficient. The main reason is that the gram weight determines the density, and the number of mesh layers determines the four-sided extensibility of the elongation. Therefore, the difference between the microfiber non-woven fabric and the conventional non-woven fabric is that it needs to be finely needled and the gram weight density is improved.

[0120] The conventional process thickness is controlled at 0.9-1.1mm. If we continue to follow this process thickness and control the coating thickness at 0.2mm, the final product thickness will still be 1.1-1.3mm, and we cannot make a product that meets the thickness requirements. If we directly slice and thin it to 0.7mm, the performance will be directly affected and significantly reduced.

[0121] Comparative Example 2

[0122] Nylon chips and polyethylene chips are melt-spun with a chip weight ratio of 50 - 60:75 - 85, and an ultra-fine fiber non-woven fabric is produced by the needling process (the average gram weight produced by the needling process is 300 g / m 2 -350 g / m 2 , with 10 - 15 layers of web laying and a linear speed of 8 - 10 m / min for the non-woven fabric production equipment. In Comparative Example 2, by changing the ratio of chip weights and further reducing the gram weight, an attempt was made to explore the changes brought about by the adjustment of the chip ratio and the change in gram weight. Continuing in this way, with the subsequent processes remaining unchanged, a low gram weight led to insufficient fiber network density, and fewer layers of web laying affected the fiber entanglement, resulting in insufficient tear performance and elongation, and a significant decline in mechanical properties (the tear strength decreased by more than 40%), and performance failure occurred.

[0123] Comparative Example 3

[0124] Nylon chips and polyethylene chips are melt-spun with a chip weight ratio of 60 - 50:85 - 75, and an ultra-fine fiber non-woven fabric is produced by the needling process (the average gram weight produced by the needling process is 380 g / m 2 -420 g / m 2 , with 25 - 35 layers of web laying and a linear speed of 8 - 10 m / min for the non-woven fabric production equipment. By adjusting the chip weight ratio without changing other process parameters, after proceeding according to this process, based on the positive correlation between the gram weight (g / m 2 ) and the density (g / cm 3 ), where the density D = gram weight W / (thickness T × 1000). When the ratio changed, the gram weight increased from 320 g / m 2 to 380 g / m², and the density increased from 0.32 - 0.42 g / cm³ to 0.38 - 0.48 g / cm³ (T = 0.9 - 1.1 mm). The densification of the fiber network increased the tear resistance, but after the fiber network was densified, the fineness of the needling affected the entanglement of the fibers, thereby affecting the strength and elongation of the finished product, resulting in the strength being too hard and easy to break, and at the same time the elongation also decreased, and the needling linear speed was affected, reducing the production efficiency. At this time, we did not dare to increase the linear speed because too fast a linear speed might lead to insufficient needling, thus affecting the structure. In summary, this scheme has drawbacks.

[0125] Comparative Example 4

[0126] ① Nylon chips and polyethylene chips with a chip weight ratio of 35 - 45:65 - 75 are then subjected to high-temperature melt mixing (260 - 290 °C) and spun to obtain sea-island fibers of polyamide blend;

[0127] ②The prepared polyamide blended sea-island fiber is made into ultra-fine fiber non-woven fabric through the needling process (the average gram weight produced by the needling process is 400 g / m 2 -460 g / m 2 , the number of laying layers is 25 - 40 layers, and the linear speed of the non-woven fabric production equipment is 3 - 5 m / min.);

[0128] ③The thickness and gram weight of the ultra-fine fiber non-woven fabric are stabilized through weighing, carding, and shaping (the shaping thickness is controlled at 0.5 - 0.8 mm), and the production of the base fabric can be completed;

[0129] ④The ultra-fine fiber non-woven fabric is made into an unopened semi-finished product through the wet impregnation process of waterborne polyurethane (the coating thickness is 0.2 mm, and the waterborne polyurethane resin is rolled into the non-woven fabric through a roller, and the gap between each pair of rollers is (fabric thickness - 0.2 mm) - (fabric thickness - 0.3 mm));

[0130] The same operations are carried out as in Comparative Example 1, and the post-treatment process is changed to conduct a comparison of the post-treatment process

[0131] ⑤The semi-finished product is immersed in hot water at a temperature of 110 - 120 °C for 60 - 80 min for fiber opening treatment, and then washed with water at 90 - 110 °C for 30 min for 1 time to obtain the fiber-opened semi-finished product;

[0132] ⑥The fiber-opened semi-finished product is dried, shaped, and air-rubbed; (when drying, the temperatures are set at 90 °C, 100 °C, 120 °C, and 145 °C respectively, the vehicle speed is 10 - 12 m / min, and the ultra-fine fiber non-woven fabric after heat setting can be cooled by 6 cold air fans at the end of the setting and drying line)

[0133] ⑦The semi-finished product after rubbing is re-rubbed through a hot rubbing machine (the hot rubbing temperatures are set at 100 °C, 110 °C, 120 °C, and 130 °C respectively, and the vehicle speed is 10 - 12 m / min);

[0134] ⑧After hot rubbing, leather grinding is carried out, and it is ground twice on both sides (the sandpaper used is 280-mesh sandpaper)

[0135] ⑨The semi-finished product after leather grinding is laminated with solvent-free polyurethane to manufacture an ultra-thin and ultra-fine leather;

[0136] By reducing the time of hot water weight reduction in ⑤ and the number of water washing times, including the hot rubbing temperature in ⑦, explore whether there is a better way to save energy consumption. After adjusting the process parameters, it is significantly found that after the finished product is made, there is residual PET in the finished product, and the hot rubbing temperature is not enough, resulting in an obvious sense of stiffness in the hand feeling and a reduction in softness. Therefore, the exploration of the lowest parameter critical point for this scheme fails.

[0137] Table 2 Comparison table of key process parameters of Comparative Examples 1 - 4

[0138]

[0139] It can be seen from Examples 1 to 4 and Comparative Examples 1 to 4 that the product prepared in Example 1 is the required ultra-thin synthetic leather for vehicles, and has the best comprehensive performance:

[0140] 1 The thickness can achieve 0.6 - 0.9 mm (such as Figure 7 / 11), which is 19% - 50% thinner than the 1.1 - 1.2 mm of normal commercially available fabrics;

[0141] 2 It can also take into account the thin and soft hand feeling and touch, effectively improving the comfort performance of the interior materials.

[0142] The above is only the preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformation made by using the present invention is within the patent protection scope of the present invention.

Claims

1. A preparation method of an ultra-thin artificial leather for vehicles, characterized in that, The preparation method of the ultra-thin ultra-fiber leather for automobile comprises the following preparation steps: S1 prepares the sea-island fiber, melts and mixes the polyamide slices and the polyethylene slices, and prepares the nylon-blended sea-island fiber through a spinning process; S2 is used to prepare ultrafine fiber nonwoven fabrics, and nylon blended sea island fibers are used to prepare ultrafine fiber nonwoven fabrics through a needle punching process; S3 weighs, combs and shapes the ultrafine fiber non-woven fabric to achieve stable thickness and weight. The thickness is 0.5-0.8mm, and the production of the base fabric is completed. S4 uses a wet process to impregnate the microfiber nonwoven fabric with water-based polyurethane to obtain an unopened semi-finished product: The coating thickness is 0.2mm. The water-based polyurethane resin is rolled into the non-woven fabric by rollers. The gap between each pair of rollers is: fabric thickness - 0.2mm ~ fabric thickness - 0.3mm; S5: The semi-finished product is immersed in hot water at a temperature of 110-120°C for 90-150 minutes, and after fiber opening treatment, it is washed with water at 90-110°C for 30 minutes, and washed twice to obtain a semi-finished product after fiber opening; S6 dries, shapes and air-kneads the semi-finished fiber products; S7 passes the semi-finished product after kneading through a hot kneading machine for further hot kneading; S8 is then polished after hot kneading, with both sides polished twice; S9 uses solvent-free polyurethane veneer to laminate the semi-finished leather after grinding to produce ultra-thin microfiber leather.

2. The preparation method of the ultra-thin superfine leather for vehicles according to claim 1, characterized in that, In S1, the weight ratio of the polyamide slices to the polyethylene slices is 35-45:65-75.

3. The preparation method of the ultra-thin superfine leather for vehicles according to claim 1, characterized in that, In S2, the average grammage produced by the needle punching process is 400 g / m 2 -460 g / m 2 , the number of laid webs is 25 - 40 layers, and the linear speed of the non-woven fabric production equipment is 3 - 5 m / min.

4. The preparation method of the ultra-thin superfine leather for vehicles according to claim 1, characterized in that, In S3, the shaping process of the ultrafine fiber nonwoven fabric is specifically as follows: S31 dries the ultrafine fiber nonwoven fabric through a 4-stage oven with different temperature gradients, with the temperatures set at 90°C, 100°C, 120°C, and 145°C, respectively, and the speed at 10-12m / min; The S32 heat-set microfiber nonwoven fabric can be cooled by 6 cold fans at the end of the setting and drying line.

5. The preparation method of the ultra-thin ultra-fiber leather for vehicles according to claim 1, characterized in that, In S4, the specific preparation steps of the fiber-opening semi-finished product are: The semi-finished product is immersed in hot water at a temperature of 110-120°C for 90-150 minutes to be deweighted, and then the fiber is opened. Then, it is washed with water at 90-110°C for 30 minutes, and washed twice to obtain the semi-finished product after fiber opening.

6. The preparation method of the ultra-thin superfine leather for vehicles according to any one of claims 1 or 5, characterized in that, In S4, The coating thickness is 0.2 mm, and the waterborne polyurethane resin is rolled into the non-woven fabric by rollers, and the gap between each pair of rollers is: cloth thickness 0.2 mm to cloth thickness 0.3 mm.

7. The preparation method of the ultra-thin superfine leather for vehicles according to claim 1, wherein, In S4, the impregnation ingredients in the wet impregnation water-based polyurethane process are: Mix water-based polyurethane (model Mier W01), leveling agent, defoamer and softener in a weight ratio of 25:0.3:0.02:1.2 per 100 parts, add them into a mixing barrel together with the pigment paste and stir evenly for 90-120 minutes to obtain the required impregnation ingredients.

8. The method for preparing the ultra-thin ultra-fiber leather for vehicles according to claim 7, characterized in that: The solid content of the aqueous polyurethane resin working fluid is 18%-22%, and the viscosity is 7000cps-8000cps; The leveling agent is any one of Tech-2550 and TEGO-410; The defoamer is any one of PX-3841 and MSD-151A; The softener is any one of S-301 and Dinamica.

9. The preparation method of the ultra-thin superfine leather for vehicles according to claim 1, wherein, The wet impregnation process of the waterborne polyurethane is solidified at a high temperature, and the temperature range is 40-45°C; During the acupuncture process described above, the needle density is 2460 - 3000 C / cm 2 .

10. The preparation method of the ultra-thin superfine leather for vehicles according to claim 1, wherein, The density range of the shaped ultra-fine fiber non-woven fabric is 0.28-0.32.

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