Suede microfiber leather with differentiated appearance and preparation method thereof

Abstract

The present invention relates to a suede microfiber leather with a differentiated appearance and a preparation method thereof, wherein the suede of the suede microfiber leather is composed of fibers in an upright form and fibers in a prostrate form, and the suede of the suede microfiber leather has a visually differentiated appearance; the visually differentiated appearance refers to the surface presenting a color brightness difference of different shades distinguishable by the naked eye; the preparation method is: (1) preparation of non-woven fabric: using a needle-punched non-woven fabric process, respectively using a spiral needle with a twisted working part and an upright conical needle; (2) impregnation of non-woven fabric; (3) curing and fiber opening; (4) peeling; (5) grinding. The suede microfiber leather with a differentiated appearance prepared by the present invention has a constant differentiated appearance effect, and after contact, the external force applied from the outside will not change the differentiated appearance effect; the fibers of most of the upright hair parts on the surface form entanglements at the bottom and prostrate, and under the polyurethane coating, the suede leather has excellent mechanical strength and less hair loss.

Description

Technical Field

[0001] The invention belongs to the technical field of suede microfiber leather, and relates to suede microfiber leather with differentiated appearance and a preparation method thereof. Background Art

[0002] Synthetic leather is a material that imitates natural leather and is artificially synthesized. As a surface material, synthetic leather also plays a role in daily decoration, such as being used in clothing, bags, household items, and car accessories. In order to achieve the differentiation of the appearance of synthetic leather, the existing technology usually conducts research on the design of textures, such as achieving different texture designs through veneer technology. The mechanism is to use release paper with a certain texture to prepare a leather texture layer to give the leather a rich appearance.

[0003] However, suede leather usually lacks the natural feel of natural suede in terms of surface nap (noodle feel). The prior art has developed a sandpapering technique to differentiate the appearance of suede leather, but it is still difficult to achieve the difference in the distribution of the nap standing up (standing hair) and lying down of natural suede, as well as the difference in the color of the suede surface.

[0004] Usually, when the length of the fluff is increased, under the action of external force, such as touching with the hand, the fluff will fall in one direction, which can form a light and dark change, but this light and dark change will change with the action of the external force, making the appearance effect here not fixed. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a suede microfiber leather with a differentiated appearance and a preparation method thereof.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A suede microfiber leather with a differentiated appearance, wherein the suede surface of the suede microfiber leather is composed of fibers in an upright state and fibers in a prostrated state, and the suede surface of the suede microfiber leather has a visually differentiated appearance;

[0008] The visually differentiated appearance refers to the surface showing different shades of color brightness that can be distinguished by the naked eye;

[0009] The area where the fibers are upright is recorded as the hair-standing portion; the upright fibers run through the thickness direction of the suede microfiber leather and have a structure of spirally interwoven fiber bundles, so that the hair-standing portion does not produce irreversible lodging deformation after being touched by external force;

[0010] The area where the fibers are in a prostrate state is recorded as a prostrate portion; the fibers in the prostrate state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and prostrate, so that the prostrate portion does not produce irreversible upright deformation after being touched by external force;

[0011] The suede thickness of the suede microfiber leather is 0.01-0.5 mm.

[0012] As the preferred technical solution:

[0013] In the suede microfiber leather with a differentiated appearance as described above, the upright hair portion and the prostrated portion are interlaced with each other in a regular or irregular distribution.

[0014] As described above, in the suede microfiber leather with a differentiated appearance, the upright hair part is relatively light in color, the prostrated part is relatively dark in color, and the color difference between light and dark is △L≥1.5.

[0015] In the above-mentioned suede microfiber leather with a differentiated appearance, the standing hair part is formed by 3 to 10 groups of microfiber bundles woven and entangled into a bundle, so that the standing hair part obtained is more upright and firm, and under the subsequent stress (such as touching the suede with hands), the deformation generated can be instantly restored after the stress is removed, so that the stability of the differentiated appearance is higher. Usually, 200 islands of sea-island fibers can be obtained after fiber opening. If a 5-hook spiral needle is selected, 5 groups of microfiber bundles together constitute a bundle of upright fibers woven and entangled by 1,000 microfibers.

[0016] As described above, the suede microfiber leather with a differentiated appearance, the microfiber can be commonly used PA6 or PET, etc.; the fineness of the microfiber is 0.01-0.55dtx, the thicker the fiber, the easier it is to stand up, and the thinner the fiber, the easier it is to fall down. At the same time, it should also be considered that the fiber cannot be too thick, so that the material loses the flexibility of the microfiber.

[0017] As described above, a suede microfiber leather with a differentiated appearance, the microfiber is a polymer with a glossiness of 100 to 180 (gloss tested at 20° using the ASTM D 2457 method). The differentiated appearance is caused by different reflections caused by light irradiating the fiber surfaces of different shapes, resulting in differences in brightness. Glossiness also has an important influence on the color brightness of the fiber. On the surface of a high-gloss fiber, the light reflected by the mirror is stronger than the diffuse reflection, and the color will look brighter; the surface of a low-gloss fiber appears darker. The inventor studied the influence of fibers of different glossiness on the brightness differences of fiber surfaces of different shapes, and found that polymer slices with a glossiness of 100 to 180 (preferably 135 to 180) can present more significant differences in brightness.

[0018] The suede microfiber leather with a differentiated appearance as described above, wherein the tensile load of the suede microfiber leather is ≥80N / 10mm, and the hair loss is ≤2mg / 100cm 2 .

[0019] The present invention also provides a method for preparing the suede microfiber leather with a differentiated appearance as described above, comprising the following steps:

[0020] (1) Preparation of nonwoven fabrics;

[0021] The needle-punched nonwoven fabric process uses a twisted needle and a vertical conical needle. The spiral needle with a twisted working part forms a spiral upright fiber bundle when it pierces the fiber, and these upright fiber bundles can form a piece of upright microfibers after impregnation, reduction and peeling; the upright conical needle forms a tangled fiber bundle when it pierces the fiber, and these tangled fiber bundles form prostrate microfibers after impregnation, reduction and peeling;

[0022] (2) Impregnation of nonwoven fabrics;

[0023] The viscosity of the impregnated water-based polyurethane is 500-2000 cP; the impregnation process is the process of the water-based polyurethane continuously filling the internal gaps. 500-2000 cP is selected to control the fluidity of the water-based polyurethane so that it is not too high to easily fill the internal tissue, nor too low to make it difficult for the water-based polyurethane to impregnate;

[0024] (3) Solidification and fiber opening;

[0025] The process is a conventional process, using water-soluble polyester as the sea phase, and after the waterborne polyurethane is cured, water is used to open the sea island fiber base cloth to obtain the ultrafine fiber base cloth;

[0026] (4) peeling;

[0027] The process is a conventional process, and the thickness error is controlled within the range of ±0.005mm. It is found in the experiment that the new surface obtained by peeling is smoother than the original surface of the microfiber base cloth before peeling, and clear upright parts and lying parts can be obtained. On the other hand, since the impregnation process of the non-woven fabric is insufficient, the water-based polyurethane resin content inside the non-woven fabric is small, while the resin content on the surface of the non-woven fabric is high. The resin content of the new surface obtained after peeling to the original non-woven surface increases from small to large. Due to the low resin content, the new surface can usually be raised after fewer grinding times, and the upright fibers are not easy to lie down.

[0028] (5) Microdermabrasion;

[0029] The new surface obtained by peeling is subjected to dermabrasion twice;

[0030] The first grinding process is: the mesh of the grinding sandpaper is 240-400 mesh, and the speed of the sandpaper is 600-1200 rpm; the second grinding process is: the mesh of the grinding sandpaper is 400-600 mesh, and the speed of the sandpaper is 1000-1600 rpm. The purpose of the first grinding is to make the suede surface have more independent fibers (this process is to remove a small amount of polyurethane attached to the fiber); the purpose of the second grinding is to get a smooth suede surface.

[0031] As the preferred technical solution:

[0032] In the method for preparing a suede microfiber leather with a differentiated appearance as described above, the thickness of the non-woven fabric in step (1) is 1 to 3 mm; in a continuous non-woven fabric preparation process, four needle looms are used, and more than four needle looms may be used depending on the actual situation;

[0033] The first needle loom had spiral needles with twisted working parts inserted into all the needle holes of the needle plate. The needle density was 1500-2400 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0034] The second acupuncture machine uses the same needle plate as the first one. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The same starting working position as the first acupuncture machine is selected, and the same acupuncture frequency and output speed are set. The acupuncture density is 250-400 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0035] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 30-40% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines is 2500-4000 needles / cm 2 within the range.

[0036] The first acupuncture machine has spiral needles with twisted working parts inserted into all the needle holes of the needle plate. The acupuncture density is determined by the needle plate, acupuncture frequency and output speed. Acupuncture density = needle density × acupuncture frequency ÷ output speed. The acupuncture density is controlled to be 1500-2400 needles / cm 2 , according to the different needle density of the needle plate, the needle frequency and output speed are set to achieve the needle density; the needle depth is to penetrate the entire fiber web;

[0037] The second acupuncture machine uses the same needle plate as the first one, that is, the position of the needle holes remains unchanged. According to the target arrangement, some of the needle holes are inserted into upright conical needles, and the remaining needle holes are not inserted. The same starting working position as the first acupuncture machine is selected, and the same acupuncture frequency and output speed are set. By controlling the needle density, 250-400 needles / cm are obtained. 2 The target needling density is 100%, and the needling depth is through the entire fiber web;

[0038] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is controlled not to penetrate the entire fiber web, and the depth is 30-40% of the thickness of the entire fiber web. Different needle plate models, needling frequencies and output speeds can be selected to control the total needling density on the fiber web surface. Taking four needling machines as an example, the sum of the needling densities of the first, second and third machines and the sum of the needling densities of the first, second and fourth machines are all 2500-4000 needles / cm 2 .

[0039] Alternatively, preferably, the same needle plate model, needling frequency and output speed as the second machine are selected, that is, the needle hole position remains unchanged, and the needle insertion position is selected to fully or partially insert the upright conical needle into the needle hole of the second machine where the needle is not inserted.

[0040] When the spiral needle with a twisted working part pierces the fibers, the fibers are distributed throughout the cross-section of the non-woven fabric. After reduction, the ultrafine fiber bundles obtained on the surface of the sheet are still upright and appear as standing hair parts. When the fibers are distributed parallel or nearly parallel to the surface, after reduction, the fibers appear to be lying down on the surface of the sheet. Since the fiber lodging is achieved by using a needle punch with a specific needle type to make the fibers internally entangled in the direction of the non-woven fabric to obtain the strength of the non-woven fabric, and the internal entanglement in the direction of the non-woven fabric is bound to be a lodging state, when only the first and second needling punches are performed, although the desired upright and lodging can be ensured, the non-woven fabric has basically no mechanical strength due to insufficient fiber entanglement. Therefore, it is necessary to perform shallow puncture on both sides to reinforce the strength of the fiber web. The depth of the shallow puncture is controlled to be 30-40% of the thickness of the entire fiber web. Under the needling of the third and fourth upright conical needles, the upright fibers on the upper and lower surfaces will be irregularly punctured and lodged, while the middle part will remain as it is. Therefore, it is necessary to obtain a fiber morphology distribution with a target upright part and a lodged part by cutting the obtained non-woven fabric from the middle piece.

[0041] During the impregnation of the non-woven fabric in step (2), the pressure roller force is 80-150 kPa and the impregnation amount is 20-50%. Generally, when obtaining the same impregnation amount, the greater the viscosity, the greater the pressure roller force required. At this stage, the control of the viscosity and the pressure roller force should be adjusted to obtain a wet fabric with an impregnation amount of 20-50%. When the impregnation amount is 20-50%, the water-based polyurethane does not fully enter the fiber structure of the non-woven fabric, and more is mainly distributed in the direction close to the surface of the non-woven fabric.

[0042] Beneficial effects:

[0043] (1) The suede microfiber leather with a differentiated appearance of the present invention has a constant differentiated appearance effect, and after contact, external force applied from the outside will not change the differentiated appearance effect;

[0044] (2) The present invention provides a method for preparing a suede microfiber leather with a differentiated appearance. By changing the needle shape and controlling the needle punching process, as well as coordinating with resin impregnation, a standing hair portion on the surface and a lying hair portion on the surface are finally obtained. The fibers of most of the standing hair portions on the surface are entangled and lie down at the bottom, and are coated with polyurethane, so that the suede leather has excellent mechanical strength and less hair loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Present different light and dark effects for different fiber forms;

[0046] Figure 2 A spiral needle with a twisted working part;

[0047] Figure 3 It is the distribution state of the polyurethane impregnation liquid in the non-woven fabric before peeling;

[0048] Figure 4 It shows the distribution state of polyurethane impregnation liquid in nonwoven fabric after peeling. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the present invention.

[0050] The term "needle penetration depth" in the present invention means the depth of the hook needle penetrating into the fiber web.

[0051] The present invention adopts the following testing method:

[0052] (1) Gloss: tested using ASTM D 2457 method at 20°;

[0053] (2) Tensile load: The tensile load of the base fabric was tested using the test method of GB / T 1040.3-2006; the tensile speed was 100 mm / min, the width × thickness of the sample was 10 mm × 1 mm; the equipment used was a universal tensile testing machine;

[0054] (3) Hair loss: GB / T 25880-2010 is used to test the hair loss of the base fabric;

[0055] (4) Visual observation of fiber distribution morphology: Method 1: observation by electron microscope; Method 2: observation of the morphology of suede leather by placing the suede leather horizontally at an angle of 5 to 10 degrees to the suede leather with the naked eye under a D65 light source;

[0056] (5) Color difference between dark and light colors △L: Use a colorimeter to measure the L values ​​of 5 random dark areas in the sample, and calculate the average value recorded as L1, and the L values ​​of 5 random light areas, and calculate the average value recorded as L2, and calculate to obtain △L=L2-L1.

[0057] Example 1

[0058] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.1mm; the area where the fibers are upright is recorded as the standing hair part, and the standing hair part is made of 5 groups of PA6 microfiber bundles hooked and entangled into a bundle, the fineness of the microfiber is 0.2dtx, and the glossiness of the microfiber material is 100; the upright fibers run through the thickness direction of the suede microfiber leather, and have a spirally interwoven fiber bundle structure, so that the standing hair part is not affected by the outside The area where the fibers are in a prostrate state is recorded as the prostrate part; the prostrate fibers are entangled with the internal fiber network in the plane direction of the suede microfiber leather and prostrate, so that the prostrate part does not produce irreversible upright deformation after being touched by external force; the erect hair part and the prostrate part are staggered with each other in an irregular distribution, the erect hair part is relatively light-colored, and the prostrate part is relatively dark-colored, the light-dark color difference △L is 3.1, and the overall surface presents different light-dark color brightness differences that can be distinguished by the naked eye, such as Figure 1 shown.

[0059] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 81N / 10mm and the hair loss is 2mg / 100cm 2 .

[0060] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0061] (1) Preparation of nonwoven fabrics;

[0062] The thickness of the nonwoven fabric is 2mm. The needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0063] Among them, the first acupuncture machine has all the needle holes of the needle plate inserted with spiral needles with twisted working parts (such as Figure 2 As shown in the figure) (select a spiral needle with 5 hooks), randomly select the needle insertion position, and the needle insertion density is 1800 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0064] The second acupuncture machine uses the same needle plate as the first acupuncture machine. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are randomly selected, and the same starting working position as the first acupuncture machine is selected. The same acupuncture frequency and output speed are set, and the acupuncture density is 300 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0065] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 35% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 3000 needles / cm 2 ;

[0066] (2) Impregnation of nonwoven fabrics;

[0067] The viscosity of the impregnated water-based polyurethane is 500 cP, the roller force is 120 kPa, and the impregnation amount is 30%;

[0068] (3) Solidification and fiber opening;

[0069] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0070] (4) peeling;

[0071] The thickness error is controlled within the range of ±0.005mm;

[0072] (5) Microdermabrasion;

[0073] The new surface obtained by peeling is subjected to dermabrasion twice;

[0074] The first grinding process is: the mesh number of grinding sandpaper: 300 mesh, the rotation speed of sandpaper: 1000 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 500 mesh, the rotation speed of sandpaper: 1000 revolutions per minute.

[0075] Through electron microscopy observation, Figure 3It is the distribution state of the polyurethane impregnation liquid in the non-woven fabric before peeling. The black dots represent the distribution state of the resin. Since the liquid carrying rate is low during impregnation, it is basically concentrated on the upper and lower surfaces of the base fabric, and peeling is done at the dotted line position; Figure 4 It is the distribution state of the polyurethane impregnation liquid in the non-woven fabric after peeling. When the surface obtained from the peeling is the surface of suede leather, less polyurethane is distributed on the surface of the peeling, which is beneficial to maintain the shape of upright fibers after grinding.

[0076] During the preparation process, the third needling machine and the fourth needling machine can select different needling depths and needling densities within the range. Since the needling depths of the third needling machine and the fourth needling machine are only 30-40% of the fiber web thickness, they will not affect the fiber lodging and upright state of the new surface obtained by the split leather. However, different needling depths and needling densities will affect the fiber entanglement at the bottom, and then affect the strength and shedding property of the suede leather. Therefore, when different needling depths and needling densities are selected, two suede leather products with different strengths and shedding properties can be obtained after splitting, that is, the preparation of two suede leather products of different specifications can be achieved in the same production process.

[0077] Comparative Example 1

[0078] A suede microfiber leather is basically the same as Example 1, except that the suede surface of the suede microfiber leather is only composed of fibers in a prostrated state, and the depth of the overall surface presents no differentiated effect.

[0079] The method for preparing the suede microfiber leather is basically the same as that in Example 1, except that in step (1), the four needle looms all use upright conical needles.

[0080] Example 2

[0081] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.1mm; the area where the fibers are upright is recorded as the standing hair part, and the standing hair part is woven and entangled into a bundle by 5 groups of PA6 microfiber bundles, the fineness of the microfiber is 0.2dtx, and the glossiness of the microfiber material is 80; the upright fibers run through the thickness direction of the suede microfiber leather, and have a spiral interwoven fiber bundle structure, so that the standing hair part is not affected by the outside The area where the fibers are in a fallen state is recorded as the fallen part; the fibers in a fallen state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and fall down, so that the fallen part does not produce irreversible upright deformation after being touched by external force; the erect hair part and the fallen part are staggered with each other in an irregular distribution, the erect hair part is relatively light-colored, and the fallen part is relatively dark-colored, the color difference △L is 1.5, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0082] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 76N / 10mm and the hair loss is 2.1mg / 100cm 2 .

[0083] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0084] (1) Preparation of nonwoven fabrics;

[0085] The thickness of the nonwoven fabric is 2mm. The needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0086] Among them, the first needle loom has all the spiral needles with twisted working parts (select spiral needles with 5 hooks) inserted into the needle holes of the needle plate, and the needle insertion positions are randomly selected. The needle density is 1800 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0087] The second acupuncture machine uses the same needle plate as the first acupuncture machine. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are randomly selected, and the same starting working position as the first acupuncture machine is selected. The same acupuncture frequency and output speed are set, and the acupuncture density is 300 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0088] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 35% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 3000 needles / cm 2 ;

[0089] (2) Impregnation of nonwoven fabrics;

[0090] The viscosity of the impregnated water-based polyurethane is 500 cP, the roller force is 120 kPa, and the impregnation amount is 30%;

[0091] (3) Solidification and fiber opening;

[0092] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0093] (4) peeling;

[0094] The thickness error is controlled within the range of ±0.005mm;

[0095] (5) Microdermabrasion;

[0096] The new surface obtained by peeling is subjected to dermabrasion twice;

[0097] The first grinding process is: the mesh number of grinding sandpaper: 300 mesh, the rotation speed of sandpaper: 1000 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 500 mesh, the rotation speed of sandpaper: 1000 revolutions per minute.

[0098] Example 3

[0099] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.1mm; the area where the fibers are upright is recorded as the standing hair part, and the standing hair part is woven and entangled into a bundle by 5 groups of PA6 microfiber bundles, the fineness of the microfiber is 0.2dtx, and the glossiness of the microfiber material is 100; the upright fibers run through the thickness direction of the suede microfiber leather, and have a structure of spirally interwoven fiber bundles, so that the standing hair part is not affected by the outside The area where the fibers are in a fallen state is recorded as the fallen part; the fibers in a fallen state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and fall down, so that the fallen part does not produce irreversible upright deformation after being touched by external force; the erect hair part and the fallen part are staggered with each other in an irregular distribution, the erect hair part is relatively light-colored, and the fallen part is relatively dark-colored, the color difference △L is 3.3, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0100] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 47N / 10mm and the hair loss is 5mg / 100cm 2 .

[0101] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0102] (1) Preparation of nonwoven fabrics;

[0103] The thickness of the nonwoven fabric is 2mm. The needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0104] Among them, the first needle loom has all the spiral needles with twisted working parts (select spiral needles with 5 hooks) inserted into the needle holes of the needle plate, and the needle insertion positions are randomly selected. The needle density is 1800 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0105] The second acupuncture machine uses the same needle plate as the first acupuncture machine. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are randomly selected, and the same starting working position as the first acupuncture machine is selected. The same acupuncture frequency and output speed are set, and the acupuncture density is 300 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0106] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 35% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 3000 needles / cm 2 ;

[0107] (2) Impregnation of nonwoven fabrics;

[0108] The viscosity of the impregnated water-based polyurethane is 500 cP, the roller force is 55 kPa, and the impregnation amount is 15%;

[0109] (3) Solidification and fiber opening;

[0110] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0111] (4) peeling;

[0112] The thickness error is controlled within the range of ±0.005mm;

[0113] (5) Microdermabrasion;

[0114] The new surface obtained by peeling is subjected to dermabrasion twice;

[0115] The first grinding process is: the mesh number of grinding sandpaper: 300 mesh, the rotation speed of sandpaper: 1000 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 500 mesh, the rotation speed of sandpaper: 1000 revolutions per minute.

[0116] Example 4

[0117] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.1mm; the area where the fibers are upright is recorded as the standing hair part, and the standing hair part is woven and entangled into a bundle by 5 groups of PA6 microfiber bundles, the fineness of the microfiber is 0.2dtx, and the glossiness of the microfiber material is 100; the upright fibers run through the thickness direction of the suede microfiber leather, and have a structure of spirally interwoven fiber bundles, so that the standing hair part is not affected by the outside The area where the fibers are in a fallen state is recorded as the fallen part; the fibers in a fallen state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and fall down, so that the fallen part does not produce irreversible upright deformation after being touched by external force; the erect hair part and the fallen part are staggered with each other in an irregular distribution, the erect hair part is relatively light-colored, and the fallen part is relatively dark-colored, the color difference △L is 3.2, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0118] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 30N / 10mm and the hair loss is 2.5mg / 100cm 2 .

[0119] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0120] (1) Preparation of nonwoven fabrics;

[0121] The thickness of the nonwoven fabric is 2mm; the needle-punched nonwoven fabric process is adopted, using two needle-punching machines, respectively using spiral needles with twisted working parts and upright conical needles;

[0122] Among them, the first needle loom has all the spiral needles with twisted working parts (select spiral needles with 5 hooks) inserted into the needle holes of the needle plate, and the needle insertion positions are randomly selected. The needle density is 1800 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0123] The second acupuncture machine uses the same needle plate as the first acupuncture machine. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are randomly selected, and the same starting working position as the first acupuncture machine is selected. The same acupuncture frequency and output speed are set, and the acupuncture density is 300 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0124] (2) Impregnation of nonwoven fabrics;

[0125] The viscosity of the impregnated water-based polyurethane is 500 cP, the roller force is 120 kPa, and the impregnation amount is 30%;

[0126] (3) Solidification and fiber opening;

[0127] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0128] (4) peeling;

[0129] The thickness error is controlled within the range of ±0.005mm;

[0130] (5) Microdermabrasion;

[0131] The new surface obtained by peeling is subjected to dermabrasion twice;

[0132] The first grinding process is: the mesh number of grinding sandpaper: 300 mesh, the rotation speed of sandpaper: 1000 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 500 mesh, the rotation speed of sandpaper: 1000 revolutions per minute.

[0133] Example 5

[0134] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.5 mm; the area where the fibers are upright is recorded as the standing hair part, and the standing hair part is woven and entangled into a bundle by 3 groups of PA6 microfiber bundles, the fineness of the microfiber is 0.4dtx, and the glossiness of the microfiber material is 120; the upright fibers run through the thickness direction of the suede microfiber leather, and have a spiral interwoven fiber bundle structure, so that the standing hair part is not affected by the outside The area where the fibers are in a fallen state is recorded as the fallen part; the fibers in a fallen state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and fall down, so that the fallen part does not produce irreversible upright deformation after being touched by external force; the erect hair part and the fallen part are staggered in an irregular distribution, the erect hair part is relatively light-colored, and the fallen part is relatively dark-colored, the color difference △L is 5.8, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0135] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 109N / 10mm and the hair loss is 3mg / 100cm 2 .

[0136] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0137] (1) Preparation of nonwoven fabrics;

[0138] The thickness of the nonwoven fabric is 3mm. The needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0139] Among them, the first needle loom has all the spiral needles with twisted working parts (select spiral needles with 3 hooks) inserted into the needle holes of the needle plate, and the needle insertion positions are randomly selected. The needle density is 1500 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0140] The second acupuncture machine uses the same needle plate as the first acupuncture machine. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are randomly selected, and the same starting working position as the first acupuncture machine is selected. The same acupuncture frequency and output speed are set, and the acupuncture density is 400 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0141] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 30% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 2500 needles / cm 2 ;

[0142] (2) Impregnation of nonwoven fabrics;

[0143] The viscosity of the impregnated water-based polyurethane is 1000 cP, the roller force is 150 kPa, and the impregnation amount is 20%;

[0144] (3) Solidification and fiber opening;

[0145] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0146] (4) peeling;

[0147] The thickness error is controlled within the range of ±0.005mm;

[0148] (5) Microdermabrasion;

[0149] The new surface obtained by peeling is subjected to dermabrasion twice;

[0150] The first grinding process is: the mesh number of grinding sandpaper: 240 mesh, the rotation speed of sandpaper: 800 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 600 mesh, the rotation speed of sandpaper: 1200 revolutions per minute.

[0151] Example 6

[0152] A suede microfiber leather with a differentiated appearance, wherein the suede surface of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede surface is 0.2 mm; the area in which the fibers are upright is recorded as the standing hair part, and the standing hair part is formed by 10 groups of PET microfiber bundles hooked and entangled into a bundle, the fineness of the microfiber is 0.08dtx, and the glossiness of the microfiber material is 180; the upright fibers run through the thickness direction of the suede microfiber leather, and have a structure of spirally interwoven fiber bundles, so that the standing hair part is not affected by After being touched by external force, irreversible lying deformation occurs; the area where the fibers are in a lying state is recorded as the lying part; the fibers in a lying state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and lie down, so that the lying part does not produce irreversible upright deformation after being touched by external force; the standing hair part and the lying part are staggered in an irregular distribution, the standing hair part is relatively light-colored, and the lying part is relatively dark-colored, and the color difference value △L is 4.5, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0153] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 99N / 10mm and the hair loss is 1.6mg / 100cm 2 .

[0154] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0155] (1) Preparation of nonwoven fabrics;

[0156] The thickness of the nonwoven fabric is 1mm; the needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0157] Among them, all the needle holes of the needle plate of the first acupuncture machine were inserted with spiral needles with twisted working parts (select spiral needles with 6 hooks), and the needle insertion positions were randomly selected. The acupuncture density was 2000 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0158] The second acupuncture machine uses the same needle plate as the first acupuncture machine. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are randomly selected, and the same starting working position as the first acupuncture machine is selected. The same acupuncture frequency and output speed are set, and the acupuncture density is 250 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0159] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 40% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 2800 needles / cm2 within the range.

[0160] (2) Impregnation of nonwoven fabrics;

[0161] The viscosity of the impregnated waterborne polyurethane is 2000cP, the roller force is 100kPa, and the impregnation amount is 35%;

[0162] (3) Solidification and fiber opening;

[0163] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0164] (4) peeling;

[0165] The thickness error is controlled within the range of ±0.005mm;

[0166] (5) Microdermabrasion;

[0167] The new surface obtained by peeling is subjected to dermabrasion twice;

[0168] The first grinding process is: the mesh number of grinding sandpaper: 350 mesh, the rotation speed of sandpaper: 1200 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 450 mesh, the rotation speed of sandpaper: 1600 revolutions per minute.

[0169] Example 7

[0170] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.05mm; the area where the fibers are upright is recorded as the upright part, and the upright part is composed of 8 groups of PET microfiber bundles hooked and entangled into a bundle, the fineness of the microfiber is 0.01dtx, and the glossiness of the microfiber material is 120; the upright fibers run through the thickness direction of the suede microfiber leather, and have a spirally interwoven fiber bundle structure, so that the upright part does not After being touched by external force, it will produce irreversible lying deformation; the area where the fibers are lying is recorded as the lying part; the fibers in the lying state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and lie down, so that the lying part does not produce irreversible upright deformation after being touched by external force; the standing hair part and the lying part are staggered in a regular distribution, the standing hair part is relatively light-colored, and the lying part is relatively dark-colored, the color difference value △L is 6.6, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0171] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 121N / 10mm and the hair loss is 0.9mg / 100cm 2 .

[0172] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0173] (1) Preparation of nonwoven fabrics;

[0174] The thickness of the nonwoven fabric is 2mm. The needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0175] Among them, the first needle loom has all the spiral needles with twisted working parts (select 8-hook spiral needles) inserted into the needle holes of the needle plate, and the needle insertion position is in a horizontal strip shape, and the needle density is 2400 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0176] The second acupuncture machine uses the same needle plate as the first one. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are in a horizontal strip shape. The same starting working position as the first acupuncture machine is selected, and the same acupuncture frequency and output speed are set. The acupuncture density is 320 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0177] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 32% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 3200 needles / cm 2 ;

[0178] (2) Impregnation of nonwoven fabrics;

[0179] The viscosity of the impregnated water-based polyurethane is 1200 cP, the roller force is 110 kPa, and the impregnation amount is 40%;

[0180] (3) Solidification and fiber opening;

[0181] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0182] (4) peeling;

[0183] The thickness error is controlled within the range of ±0.005mm;

[0184] (5) Microdermabrasion;

[0185] The new surface obtained by peeling is subjected to dermabrasion twice;

[0186] The first grinding process is: the mesh number of grinding sandpaper: 300 mesh, the rotation speed of sandpaper: 700 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 480 mesh, the rotation speed of sandpaper: 1300 revolutions per minute.

[0187] Example 8

[0188] A suede microfiber leather with a differentiated appearance, the suede of the suede microfiber leather is composed of upright fibers and prostrated fibers, and the thickness of the suede is 0.01 mm; the area where the fibers are upright is recorded as the standing hair part, and the standing hair part is composed of 6 groups of PET microfiber bundles hooked and entangled into a bundle, the fineness of the microfiber is 0.55dtx, and the glossiness of the microfiber material is 100; the upright fibers run through the thickness direction of the suede microfiber leather, and have a structure of spirally interwoven fiber bundles, so that the standing hair part does not After being touched by external force, it will produce irreversible lying deformation; the area where the fibers are lying is recorded as the lying part; the fibers in the lying state are entangled with the internal fiber web in the plane direction of the suede microfiber leather and lie down, so that the lying part does not produce irreversible upright deformation after being touched by external force; the standing hair part and the lying part are staggered in a regular distribution, the standing hair part is relatively light-colored, and the lying part is relatively dark-colored, the color difference value △L is 6.1, and the overall surface presents different shades of color brightness that can be distinguished by the naked eye.

[0189] The tensile load of the obtained suede microfiber leather with a differentiated appearance is 130N / 10mm and the hair loss is 0.5mg / 100cm 2 .

[0190] The preparation method of the above-mentioned suede microfiber leather with differentiated appearance comprises the following specific steps:

[0191] (1) Preparation of nonwoven fabrics;

[0192] The thickness of the nonwoven fabric is 3mm. The needle-punched nonwoven fabric process is adopted, and four needle-punching machines are used, respectively using spiral needles with twisted working parts and upright conical needles;

[0193] Among them, the first needle loom has all the spiral needles with twisted working parts (select 9-hook spiral needles) inserted into the needle holes of the needle plate, and the needle insertion position is horizontally strip-shaped, and the needle density is 2000 needles / cm 2 , the needle penetration depth is through the entire fiber web;

[0194] The second acupuncture machine uses the same needle plate as the first one. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The needle insertion positions are in a horizontal strip shape. The same starting working position as the first acupuncture machine is selected, and the same acupuncture frequency and output speed are set. The acupuncture density is 280 needles / cm 2, the needle penetration depth is through the entire fiber web;

[0195] The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 36% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines are all 4000 needles / cm 2 within the scope of

[0196] (2) Impregnation of nonwoven fabrics;

[0197] The viscosity of the impregnated water-based polyurethane is 1500cP, the roller force is 80kPa, and the impregnation amount is 50%;

[0198] (3) Solidification and fiber opening;

[0199] Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric;

[0200] (4) peeling;

[0201] The thickness error is controlled within the range of ±0.005mm;

[0202] (5) Microdermabrasion;

[0203] The new surface obtained by peeling is subjected to dermabrasion twice;

[0204] The first grinding process is: the mesh number of grinding sandpaper: 400 mesh, the rotation speed of sandpaper: 600 revolutions per minute; the second grinding process is: the mesh number of grinding sandpaper: 500 mesh, the rotation speed of sandpaper: 1400 revolutions per minute.

Claims

1. A suede microfiber leather with a differentiated appearance, characterized in that: The suede surface of the suede microfiber leather is composed of fibers in an upright state and fibers in a prostrated state, and the suede surface of the suede microfiber leather has a visually differentiated appearance; The visually differentiated appearance refers to the surface showing different shades of color brightness that can be distinguished by the naked eye; The area where the fibers are upright is recorded as the hair-standing portion; the upright fibers run through the thickness direction of the suede microfiber leather and have a structure of spirally interwoven fiber bundles, so that the hair-standing portion does not produce irreversible lodging deformation after being touched by external force; The area where the fibers are in a prostrated state is recorded as a prostrated portion; the prostrated fibers are entangled with the internal fiber web in the plane direction of the suede microfiber leather and prostrated, so that the prostrated portion does not produce irreversible upright deformation after being touched by external force; The structure of the erected part is formed by a spiral needle with a twisted working part, followed by impregnation, reduction and peeling; the structure of the prostrated part is formed by a vertical conical needle, followed by impregnation, reduction and peeling; The erected hair part is relatively light in color, and the prostrated part is relatively dark in color, and the color difference between light and dark is △L≥1.5; The hair-standing part is composed of 3 to 10 groups of ultrafine fiber bundles woven and entangled into a bundle; the raw material of the ultrafine fiber is a polymer with a glossiness of 100 to 180; The suede thickness of the suede microfiber leather is 0.01-0.5 mm.

2. The suede microfiber leather with a differentiated appearance according to claim 1, characterized in that: The erected hair parts and the prostrated hair parts are interlaced with each other in a regular or irregular distribution.

3. The suede microfiber leather with a differentiated appearance according to claim 1, characterized in that: The fineness of the ultrafine fiber is 0.01-0.55 dtx.

4. The suede microfiber leather with a differentiated appearance according to claim 1, characterized in that: The tensile load of the suede microfiber leather is ≥80N / 10mm, and the hair loss is ≤2mg / 100cm 2 .

5. A method for preparing a suede microfiber leather with a differentiated appearance as claimed in any one of claims 1 to 4, characterized in that The steps include: (1) Preparation of non-woven fabrics; The needle punched nonwoven fabric process uses spiral needles with twisted working parts and upright conical needles respectively; (2) Impregnation of non-woven fabrics; The viscosity of the water-based polyurethane is 500~2000cP; (3) Curing and fiber opening; Using water-soluble polyester as the sea phase, after the waterborne polyurethane is cured, water is used to open the sea island fiber base fabric to obtain the ultrafine fiber base fabric; (4) peeling; The thickness error is controlled within the range of ±0.005mm; (5) Dermabrasion; The new surface obtained by peeling is subjected to dermabrasion twice; The first grinding process is: the mesh number of grinding sandpaper: 240~400 mesh, the speed of sandpaper: 600~1200 revolutions per minute; The second grinding process is: grinding sandpaper mesh number: 400~600 mesh, sandpaper speed: 1000~1600 revolutions per minute.

6. The method for preparing suede microfiber leather with differentiated appearance according to claim 5, characterized in that: The thickness of the non-woven fabric in step (1) is 1-3 mm; The first needle loom had spiral needles with twisted working parts inserted into all the needle holes of the needle plate. The needle density was 1500~2400 needles / cm 2 , the needle penetration depth is through the entire fiber web; The second acupuncture machine uses the same needle plate as the first one. Some of the needle holes of the needle plate of the second acupuncture machine are inserted with upright conical needles, and the remaining needle holes are not inserted with needles. The same starting working position as the first acupuncture machine is selected, and the same acupuncture frequency and output speed are set. The acupuncture density is 250~400 needles / cm 2 , the needle penetration depth is through the entire fiber web; The third and fourth needling machines perform shallow needling on the upper and lower surfaces of the fiber web respectively, and the needling depth is 30-40% of the thickness of the entire fiber web. The sum of the needling density of the first, second and third needling machines and the sum of the needling density of the first, second and fourth needling machines is 2500-4000 needles / cm 2 within the range.

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