Anisotropic non-woven fabric polishing pad and preparation process thereof

Abstract

The invention relates to the technical field of polishing materials, and particularly discloses an anisotropic non-woven fabric polishing pad and a preparation process thereof, and the preparation process comprises the following steps: uniformly spraying a polyurethane solvent on a mold to form a fiber layer; linear fibers and spiral fibers are laid in a staggered mode through the needling technology, and a fiber network with the anisotropic springback characteristic is formed; and the mold with the fiber network is put into a drying oven to be heated and cured, after curing is completed, the mold is cut into the proper size, and the finished polishing pad is obtained. The prepared polishing pad has good polishing efficiency and polishing effect, and also has the advantages of low cost and convenience in large-scale production.

Description

Technical Field

[0001] This invention relates to the field of polishing materials technology, and in particular to an anisotropic nonwoven polishing pad and its preparation process. Background Technology

[0002] In today's precision surface treatment industry, such as the polishing of optical glass, semiconductors, and metal products, the performance of polishing materials plays a decisive role in the quality of the final product. Currently, most common polishing materials on the market are homogeneous, such as traditional non-woven fabrics or sponges. These materials have a relatively simple fiber structure, and when faced with the demands of high-precision, high-efficiency surface polishing, they are gradually revealing many shortcomings.

[0003] Traditional polishing pads present an inherent contradiction when dealing with complex surfaces. On the one hand, pursuing high polishing efficiency often requires increasing the contact pressure between the polishing pad and the surface being polished, as well as the relative speed of movement. However, this approach struggles to guarantee fine polishing quality, especially when dealing with microscopically uneven surfaces, easily leaving scratches, pits, and other defects that fail to meet the stringent surface roughness and precision requirements of high-end products. On the other hand, prioritizing fine polishing quality and reducing contact pressure and movement speed leads to a significant drop in polishing efficiency, making it difficult to meet the time and cost constraints of large-scale production.

[0004] To improve polishing performance, many researchers have actively explored various approaches. Some have attempted to enhance the performance of polishing pads by adding special fillers, such as microparticles with high hardness or unique physicochemical properties, hoping to improve the pad's cutting ability and surface smoothness. Other studies focus on modifying the substrate, developing novel polymer or composite materials as the base material for polishing pads. However, these approaches generally suffer from high costs. The preparation and addition of special fillers are complex, and the development and production of novel substrates require significant financial and technological resources. Furthermore, these methods often require specialized equipment and processes in practice, making large-scale industrial applications difficult.

[0005] In view of the above-mentioned technologies, the inventors believe that it is necessary to develop a new type of polishing pad and its preparation process. Summary of the Invention

[0006] To address the technical deficiencies of existing technologies, this application provides an anisotropic nonwoven polishing pad and its preparation method.

[0007] In a first aspect, this application provides a method for preparing an anisotropic nonwoven polishing pad, employing the following technical solution: A method for preparing an anisotropic nonwoven polishing pad includes the following steps: S1: The polyurethane solvent is evenly sprayed onto the mold to form a fiber layer; S2: Straight and spiral fibers are laid out alternately using a needle punching process to form a fiber network with anisotropic resilience; S3: The mold with the fiber network is placed in an oven for heating and curing. After curing, it is cut to the appropriate size to obtain the finished polishing pad.

[0008] By adopting the above scheme, a fiber network with anisotropic resilience is constructed. The linear fibers ensure efficient transmission of grinding force, while the spiral fibers achieve elastic adhesion to the workpiece surface. This solves the defects of traditional polishing pads, which are either "insufficient grinding force or poor adhesion", and lays the structural foundation for balancing polishing efficiency and low damage.

[0009] Preferably, the viscosity of the polyurethane solvent in step S1 is 150-200 mPa·s.

[0010] By adopting the above scheme, it is ensured that the solvent is easily atomized during the spraying process and forms a continuous and dense fiber layer, avoiding the fiber layer from being loose due to too low viscosity or the fiber from being brittle due to too high viscosity. At the same time, it is compatible with the subsequent high-pressure spraying process, reduces fiber agglomeration, and ensures the uniformity of the fiber layer.

[0011] Preferably, the polyurethane solvent in step S1 further includes 1%-3% nanoparticles.

[0012] By adopting the above scheme, nanoparticles can uniformly fill the gaps between fibers and form a "particle-matrix" composite structure with polyurethane molecular chains: on the one hand, it enhances the rigidity of the fiber network and improves the hardness and wear resistance of the polishing pad; on the other hand, it inhibits the thermal motion of polyurethane molecular chains, optimizes the stability of polishing rate under high temperature conditions, and does not change the target rebound rate, thus achieving "performance upgrade without affecting core elasticity".

[0013] Preferably, the nanoparticles are one or more of nano-silica or nano-alumina.

[0014] By adopting the above scheme, the advantages of both types of particles can be flexibly utilized: nano-silica alone can reduce scratches and improve temperature stability, while nano-alumina alone can enhance wear resistance and extend life. The combination of these two types of particles can balance low scratches and high wear resistance, making it suitable for polishing various workpieces and solving the problem of limited reinforcement effect of single particles.

[0015] Preferably, the spraying in step S1 is high-pressure spraying, with a spraying pressure of 1.5-2 MPa.

[0016] By adopting the above solution, polyurethane solvent can be fully atomized into fibers with uniform diameter, avoiding fiber layer thickness fluctuations and local defects caused by ordinary spraying, ensuring the spatial continuity and consistency of the fiber network, thereby reducing pressure concentration during grinding, reducing the risk of scratches, and improving the uniformity of grinding rate.

[0017] Preferably, the ratio of straight to spiral fibers in step S2 is (6.5-8):(2-3.5).

[0018] By adopting the above scheme, the rigidity and elasticity balance of the fiber network can be precisely controlled: the straight fibers within the proportional range ensure efficient transmission of abrasive force, while the spiral fibers provide appropriate elasticity, avoiding deviations in the rebound rate caused by a single fiber, and providing structural support for subsequently locking in a 40%-60% rebound rate.

[0019] Preferably, the heating and curing conditions for step S3 are constant temperature curing at 80-100℃ for 90-120 minutes.

[0020] By adopting the above scheme, polyurethane can be fully crosslinked but not excessively: the crosslinking reaction within the temperature and time range can form a three-dimensional crosslinked network with appropriate density, which avoids insufficient crosslinking caused by low temperature and short time, and prevents excessive crosslinking caused by high temperature and long time, ensuring the stability of the elastic recovery ability of the fiber network and helping the rebound rate to accurately fall within the target range.

[0021] Secondly, this application provides an anisotropic nonwoven polishing pad, employing the following technical solution: An anisotropic nonwoven polishing pad is prepared by the above-mentioned method for preparing anisotropic nonwoven polishing pads.

[0022] By adopting the above solution, a fiber network with "rigid-elastic balance" can efficiently transmit grinding force while achieving flexible adhesion to the workpiece surface. It also has excellent wear resistance and high temperature stability, solving the technical defect of traditional polishing pads that "efficiency and damage are difficult to balance".

[0023] Preferably, the resilience of the anisotropic nonwoven polishing pad is 40%-60%.

[0024] By adopting the above solution, this rebound rate range can perfectly match the core requirements of the polishing scenario: avoiding both excessively low and excessively high rebound rates, ensuring "sufficient grinding force and good fit" during the polishing process, balancing efficient polishing with low damage, and ensuring the uniformity and stability of the polishing rate.

[0025] In summary, this application has the following beneficial effects: 1. Based on the principles of fiber structure and elasticity, this application constructs a fiber network of "rigid support + elastic fit" by optimizing the ratio of straight to spiral fibers (6.5-8):(2-3.5). Combined with a target rebound rate of 40%-60%, the polishing pad can efficiently transmit grinding force through straight fibers to ensure polishing efficiency, and can also adapt to the micro-uneven surface of the workpiece and reduce local pressure concentration by utilizing the elasticity of spiral fibers. This significantly improves the adaptability to complex surfaces and solves the problem of "difficulty in balancing grinding force and fit" in traditional polishing pads.

[0026] 2. Based on the principles of process adaptation and cost optimization, this application adopts a specific preparation process of "1.5-2MPa high-pressure spraying + 80-100℃ constant temperature curing for 90-120 minutes". On the one hand, high-pressure spraying ensures that the polyurethane solvent is uniformly atomized into a continuous fiber layer, reducing raw material waste and subsequent rework costs. On the other hand, precise curing parameters avoid performance defects caused by excessive or insufficient cross-linking. Stable production can be achieved without complex equipment, taking into account both high performance and the economy of large-scale industrial production, breaking the limitation that "high performance must be high cost".

[0027] 3. This application relies on the composite reinforcement principle of nanoparticles and introduces nano-silica and / or nano-alumina. Nano-silica can fill the fiber gaps, refine the grinding interface to reduce scratches and inhibit the thermal motion of molecular chains, while nano-alumina can enhance the hardness and wear resistance of the fiber network. The two, used alone or in combination, can improve the wear resistance and high-temperature stability of the polishing pad from the microstructure level, so that it can maintain stable performance under extreme polishing conditions of high temperature and high friction, expand the application scenarios, and solve the problem that traditional polishing pads are prone to failure under extreme working conditions. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the embodiments.

[0029] The raw materials used in the embodiments and comparative examples of this invention are all conventional commercially available products.

[0030] Example 1 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Using a spraying device, a polyurethane solvent with a viscosity of 175 mpa·s is uniformly sprayed onto the mold under a pressure of 1.8 MPa to form a fiber layer; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 7:3. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing. Heat and cure at 80°C for 100 minutes, then let it cool naturally to room temperature. Cut to the appropriate size to obtain the finished polishing pad.

[0031] The actual measured resilience of the nonwoven polishing pad in this embodiment is 50%.

[0032] Resilience rate = [(T3-T2) / (T1-T2)]×100%; where T1 is the thickness of the nonwoven polishing pad after 60s of no load and 30kpa pressure, T2 is the thickness of the nonwoven polishing pad after 60s of 180kpa pressure from state T1, and T3 is the thickness of the nonwoven polishing pad after 60s of 30kpa pressure from state T2 back to no load.

[0033] Example 2 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Using a spraying device, a polyurethane solvent with a viscosity of 175 mpa·s is uniformly sprayed onto the mold under a pressure of 1.8 MPa to form a fiber layer; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 8:2. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing at 100°C for 90 minutes, then let it cool naturally to room temperature, cut it to the appropriate size, and obtain the finished polishing pad.

[0034] The actual measured resilience of the nonwoven polishing pad in this embodiment was 40%.

[0035] Example 3 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Using high-pressure spraying equipment, a polyurethane solvent solution with a viscosity of 190 mpa·s is uniformly sprayed onto the mold under a pressure of 1.5 MPa to form a fiber layer; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 6.5:3.5. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing at 85°C for 120 minutes, then let it cool naturally to room temperature, cut it to the appropriate size, and obtain the finished polishing pad.

[0036] The actual resilience of the nonwoven polishing pad in this embodiment was measured to be 60%.

[0037] Example 4 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Using a high-pressure spraying device, a polyurethane solvent solution with a viscosity of 190 mpa·s is uniformly sprayed onto the mold under a pressure of 2 MPa to form a fiber layer; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 6.5:3.5. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing. Curing is carried out at 90°C for 110 minutes. Then, it is allowed to cool naturally to room temperature and cut to the appropriate size to obtain the finished polishing pad.

[0038] The actual resilience of the nonwoven polishing pad in this embodiment was measured to be 60%.

[0039] Example 5 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Add 1% by mass of nano-silica to a polyurethane solvent with a viscosity of 175 mpa·s, and use a spraying device to uniformly spray the polyurethane solvent onto the mold under a pressure of 1.8 MPa to form a fiber layer. The particle size of nano-silica is 50 nm; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 7:3. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing. Curing at a constant temperature of 100℃ for 100 minutes, then allowing it to cool naturally to room temperature, and cut it to the appropriate size to obtain the finished polishing pad.

[0040] The actual measured resilience of the nonwoven polishing pad in this embodiment is 50%.

[0041] Example 6 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Add 3% by weight of nano-silica to a polyurethane solvent with a viscosity of 175 mpa·s and disperse it evenly with an ultrasonic disperser. Then, use a spraying device to uniformly spray the polyurethane solvent onto the mold under a pressure of 1.8 MPa to form a fiber layer. The particle size of nano-silica is 100 nm; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 7:3. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing. Curing is carried out at a constant temperature of 85℃ for 100 minutes. Then, it is allowed to cool naturally to room temperature and cut to the appropriate size to obtain the finished polishing pad.

[0042] The actual measured resilience of the nonwoven polishing pad in this embodiment is 50%.

[0043] Example 7 An anisotropic nonwoven polishing pad is prepared according to the following method: S1: Add 2% by weight of nano-silica and 1% by weight of nano-alumina to a polyurethane solvent with a viscosity of 175 mpa·s, and disperse them evenly with an ultrasonic disperser. Then, use a spraying device to uniformly spray the polyurethane solvent onto the mold under a pressure of 1.8 MPa to form a fiber layer. The particle size of nano-silica is 100 nm; S2: A fiber network with anisotropic resilience is formed by interlacing straight and spiral fibers using a needle-punching process. The ratio of straight to spiral fibers is 7:3. S3: Place the mold with the fiber network into a hot air circulating oven for heating and curing. Curing is carried out at a constant temperature of 85℃ for 100 minutes. Then, it is allowed to cool naturally to room temperature and cut to the appropriate size to obtain the finished polishing pad.

[0044] The actual measured resilience of the nonwoven polishing pad in this embodiment is 50%.

[0045] Comparative Example 1 A nonwoven polishing pad, which differs from Example 1 in that the needle punching process in step S2 only lays straight fibers.

[0046] The actual measured resilience of this comparative nonwoven polishing pad was 35%.

[0047] Comparative Example 2 A nonwoven polishing pad, which differs from Example 1 in that the needle punching process in step S2 only lays spiral fibers.

[0048] The actual measured resilience of this comparative nonwoven polishing pad was 70%.

[0049] Comparative Example 3 A nonwoven polishing pad, which differs from Example 1 in that the polyurethane solvent used in step S1 has a viscosity of 300 mPa·s.

[0050] The actual measured resilience of the nonwoven polishing pad in this comparative example was 50%.

[0051] Comparative Example 4 A nonwoven polishing pad, which differs from Example 1 in that the polyurethane solvent used in step S1 is applied by ordinary spraying.

[0052] The actual measured resilience of the nonwoven polishing pad in this comparative example was 45%.

[0053] The following tests were conducted on the performance of the nonwoven polishing pads of Examples 1-7 and Comparative Examples 1-4: 1. Hardness test The hardness of the non-woven abrasive pad was tested using a Shore A hardness tester, and the test results were recorded. 2. Grinding effect test Use grinding equipment and control the grinding equipment parameters: the upper grinding disc speed is 40 r / min, the lower grinding disc speed is 40 r / min, and the grinding pressure is 0.5 MPa; use commercially available grinding fluid. The objects to be ground are: optical glass and metal products (copper alloy products); The polishing rate (unit: nm / min) is calculated as follows: Polishing rate = (thickness before polishing - thickness after polishing) / polishing time; the scratch rating is as follows: no scratches, grade 0; 1-3 scratches, grade 1; 4-6 scratches, grade 2; 6-10 scratches, grade 3; 11-15 scratches, grade 4; more than 16 scratches, grade 5.

[0054] 3. Wear rate test Wear rate (μm / min) = average wear amount.

[0055] 4. High temperature resistance test The polishing rate under high temperature conditions was tested and the rate of change of polishing rate compared to that under normal conditions was calculated.

[0056] 5. Non-uniformity: First, select 49 locations on the surface of the polished object for measurement, and record the thickness at the selected points before and after the polishing test. The non-uniformity of the polishing rate can be calculated by the maximum (Max) and minimum (Min) difference in thickness at 25 locations measured before and after the test, and the average thickness. The calculation formula is: Polishing rate non-uniformity = 100 * (Max - Min) / average value.

[0057] The results are detailed in Table 1.

[0058] Table 1 Performance Test Results As shown in Table 1, the polishing rate, scratch score, and non-uniformity of the nonwoven polishing pads in Examples 1-7 are all superior to those in Comparative Examples 1-4. This indicates that the present invention, through technical features such as high-pressure spraying, limiting the viscosity of the polyurethane solvent, a specific ratio of linear to helical fibers, and precise control of the resilience rate to 40%-50%, enables the nonwoven polishing pads of the present invention to possess both good polishing rate and polishing effect. Simultaneously, the wear rate of the nonwoven polishing pads in Examples 1-7 is also lower than that of the nonwoven polishing pads in Comparative Examples 1-4, which also demonstrates that the nonwoven polishing pads of the present invention have good wear resistance and a long service life.

[0059] Comparing Examples 1-2 and Comparative Examples 1-2, it can be seen that the polishing rates of optical glass and metal products in Examples 1-2 are significantly higher than those in Comparative Examples 1-2, and the scratch scores are also significantly better. Furthermore, the rebound rate of Examples 1-2 is within a reasonable range of "rigidity-elasticity balance," while Comparative Example 1, using only straight fibers, has a lower rebound rate, and Comparative Example 2, using only spiral fibers, has an excessively high rebound rate. In principle, straight fibers possess high rigidity, enabling efficient transmission of grinding pressure during the polishing process and ensuring cutting efficiency on the workpiece surface; spiral fibers, on the other hand, possess excellent elasticity, allowing them to conform to the microscopically uneven surface of the workpiece and reduce localized pressure concentration during grinding. When the two are combined in a specific ratio, a complementary structure of "rigid support + elastic conformation" is formed. This avoids the problems of poor conformation and increased scratches caused by insufficient elasticity when using straight fibers alone, and also solves the defects of weak grinding force transmission and low polishing rate caused by the lack of rigidity when using spiral fibers alone. This fully highlights the key role of fiber synergy in improving the dual performance of the polishing pad in terms of both "efficiency" and "precision."

[0060] Compared to Example 1, Examples 3-4 show improved polishing rates for both optical glass and metal products, further optimized scratch scores from a "good" level, and reduced grinding rate inhomogeneity. The core reason is that Examples 3-4 optimized key process parameters: adjusting the viscosity of the polyurethane solvent while maintaining the high-pressure spraying pressure within a reasonable range. From a theoretical perspective, a viscosity suitable for high-pressure atomization can form a fiber layer with uniform diameter and regular distribution; coupled with appropriate high-pressure atomization pressure, fiber agglomeration can be further reduced, ensuring the spatial continuity and consistency of the fiber network. This uniform and dense fiber network allows the grinding force to be transmitted more smoothly to the workpiece surface, avoiding localized under- or over-grinding. This improves the polishing rate while reducing the risk of scratches and rate fluctuations, demonstrating the significant importance of solvent characteristics and spraying parameter optimization for grinding stability.

[0061] Compared to Example 1, Examples 5-7 show a significant improvement in hardness, a marked reduction in wear rate, and a substantial optimization in high-temperature performance change rate. Furthermore, Examples 6-7 achieve a scratch-free effect. This performance improvement stems from the addition of specific proportions of nano-silica and nano-alumina in Examples 5-7. From a microscopic perspective, nanoparticles can uniformly fill the tiny gaps between polyurethane fibers, forming a "particle-matrix" composite structure with the polyurethane molecular chains. This enhances the overall rigidity of the fiber network to increase hardness and resists frictional wear during polishing, reducing the wear rate. Simultaneously, the high thermal stability of the nanoparticles inhibits the thermal motion of the polyurethane molecular chains at high temperatures, reducing fiber structure softening and deformation, thereby optimizing rate stability under high-temperature conditions. In addition, nanoparticles refine the grinding contact interface, preventing scratches caused by sudden increases in local pressure. When multiple nanoparticles are added synergistically, they integrate the reinforcing advantages of different particles, further enhancing the overall performance of the polishing pad and demonstrating the synergistic effect between nanoparticles.

[0062] Compared to Example 1, Comparative Example 3 showed a significant decrease in polishing rates for both optical glass and metal products, a worse scratch score, and increased grinding rate inhomogeneity. The core issue lies in the fact that the viscosity of the polyurethane solvent in Comparative Example 3 far exceeded the optimized range. From a process principle perspective, excessively high viscosity makes it difficult for the solvent to be fully torn into uniform fibers during high-pressure atomization spraying, easily leading to fiber agglomeration. Agglomerated fibers result in uneven fiber network distribution, causing localized pressure concentration and insufficient grinding force during grinding. This reduces the overall polishing rate, increases the probability of scratches, and also leads to greater differences in grinding rates between different areas, clearly demonstrating the need to strictly control the viscosity of the polyurethane solvent within the optimized range.

[0063] Compared to Example 1, Comparative Example 4 showed a significant decrease in polishing rates for both optical glass and metal products, along with worse scratch scores and uneven grinding rates. The key reason is that Comparative Example 4 used a conventional spraying method instead of high-pressure atomization spraying. From a process principle perspective, the pressure and atomization effect of conventional spraying cannot meet the requirements, making it difficult to uniformly disperse the polyurethane solvent into continuous fibers. This easily leads to thickness fluctuations and localized defects in the fiber layer. During the grinding process, this defective fiber layer cannot stably transmit grinding force, easily resulting in localized over- or under-grinding, thus reducing the polishing rate, increasing the risk of scratches, and exacerbating grinding rate fluctuations. This highlights the necessity of high-pressure atomization spraying for ensuring the performance of the polishing pad.

[0064] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method of producing an anisotropic nonwoven polishing pad, characterized by, The method comprises the following steps: S1: uniformly spraying polyurethane solvent on the mold to form a fiber layer; S2: using needle punching process to stagger the linear and spiral fibers to form a fiber network with anisotropic resilience characteristics; S3: placing the mold with the fiber network into an oven for heating and curing, and cutting to a suitable size after curing to obtain a finished polishing pad.

2. The method of claim 1 wherein the anisotropic nonwoven polishing pad is prepared by the steps of: The viscosity of the polyurethane solvent in the S1 step is 150-200 mpa・s.

3. The method for preparing an anisotropic nonwoven polishing pad according to claim 1, characterized in that: The polyurethane solvent in the S1 step further comprises 1%-3% of nanoparticles.

4. The method of claim 3, wherein the nonwoven pad is anisotropic. The nanoparticles are one or more of nanosilica or nanoalumina.

5. The method for preparing an anisotropic nonwoven polishing pad according to claim 1, characterized in that: The spraying in the S1 step is high-pressure spraying, and the spraying pressure is 1.5-2 MPa.

6. The method of claim 1 wherein the anisotropic nonwoven polishing pad is prepared by the steps of: The ratio of the linear and spiral fibers in the S2 step is (6.5-8):(2-3.5).

7. The method for preparing an anisotropic nonwoven polishing pad according to claim 1, characterized in that: The heating and curing conditions in the S3 step are constant temperature curing at 80-100℃ for 90-120 minutes.

8. An anisotropic nonwoven polishing pad, characterized by: The anisotropic non-woven polishing pad is prepared by the method of any one of claims 1-7.

9. The anisotropic nonwoven polishing pad of claim 8, wherein: The resilience rate of the anisotropic non-woven polishing pad is 40%-60%.

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