A polishing pad based on a fiber skeleton and a processing technology

Abstract

This invention relates to the field of polishing tool technology, specifically disclosing a polishing pad based on a fiber skeleton and its processing technology. The polishing pad comprises a three-dimensional fiber skeleton composed of surface-modified nylon fibers, an adhesive layer chemically bonded to the surface of the modified nylon fibers, abrasive particles uniformly distributed in the adhesive layer, and directional dust removal channels distributed within the three-dimensional fiber skeleton. These directional dust removal channels are formed by dissolving and removing soluble sacrificial fibers in a solvent after molding. The abrasive particles exhibit a gradient distribution from fine to coarse on the three-dimensional fiber skeleton. This invention simultaneously achieves precise gradient distribution of abrasive particles and directional, active dust removal, effectively eliminating the grinding performance degradation caused by dust clogging in traditional polishing pads, and improving production efficiency through a non-flipping integrated pressing plate process.

Description

Technical Field

[0001] This invention relates to the field of polishing tool technology, and more specifically to a polishing disc based on a fiber skeleton and its processing technology. Background Technology

[0002] Polishing pads (or abrasive fabric pads) are essential consumables in machining and surface treatment, widely used in processes such as surface grinding, deburring, and mirror polishing of metallic and non-metallic materials. Existing technologies mainly include the following categories: (1) Non-woven fabric-based polishing pads: The abrasive is embedded between the fibers by resin impregnation and overall curing. The main defects of this type of product are: the gluing and sanding processes are carried out simultaneously, the abrasive distribution is uneven, and the grinding stability is poor; after the resin is cured, semi-closed pores are formed, the dust discharge path is blocked, and the grinding performance decays rapidly after continuous use.

[0003] (2) Foam / sponge-based polishing pads: Closed-cell or semi-open-cell polyurethane foam is used as the carrier. The closed-cell structure causes chips to be unable to be discharged in time, resulting in prominent clogging problems. In addition, the product has a large amount of compression deformation, making it unsuitable for precision surface grinding.

[0004] (3) Three-dimensional fiber grinding wheel: The three-dimensional open skeleton is constructed with nylon fiber, which has a certain dust removal capacity. However, the abrasive and adhesive are applied as a whole by impregnation method, which cannot be independently and accurately measured. The pores in the skeleton are randomly distributed, and the dust discharge depends on the pore connectivity, which cannot achieve directional active discharge. At the same time, the traditional molding process requires cotton turning operation, which is complicated and the interlayer bonding is unstable.

[0005] In summary, existing technologies have significant shortcomings in terms of precise abrasive application, proactive dust removal, and process simplification. There is an urgent need to develop a new type of polishing disc and its processing technology that can solve the above problems simultaneously. Summary of the Invention

[0006] The purpose of this invention is to provide a polishing disc based on a fiber skeleton and a processing technology to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, in one aspect, the present invention provides a polishing sheet based on a fiber skeleton, comprising: A three-dimensional fiber skeleton composed of surface-modified nylon fibers; An adhesive layer chemically bonded to the surface of the modified nylon fiber; Abrasive particles evenly distributed in the adhesive layer; And directional dust removal channels distributed within the three-dimensional fiber skeleton; The directional dust removal channel is formed by dissolving and removing soluble sacrificial fibers with a solvent after molding; The abrasive is distributed in a gradient from fine to coarse on the three-dimensional fiber skeleton.

[0008] After modification, active groups (amino and hydroxyl groups) are introduced into the surface of nylon fibers. These groups form chemical bonds with the adhesive, which firmly anchors the adhesive layer to the fiber surface through chemical bonds. The abrasive is firmly held in the reinforced adhesive layer, which significantly improves the retention rate compared to simple physical embedding. The gradient abrasive distribution allows a single polishing disc to complete both rough and fine grinding processes. The directional dust removal channel actively removes dust by utilizing airflow and friction during the grinding process, fundamentally eliminating the risk of blockage.

[0009] Preferably, the modified nylon fiber is treated with a silane coupling agent or plasma treatment. The silanol groups treated with the silane coupling agent form Si-OC covalent bonds with the hydroxyl groups on the surface of the nylon cotton, while the aminopropyl groups react chemically with the epoxy groups of the subsequent adhesive to form a chemical bond chain of fiber-coupling agent-adhesive, which significantly improves the retention force of the abrasive on the three-dimensional fiber skeleton.

[0010] Preferably, the soluble sacrificial fiber is polyvinyl alcohol fiber, with a dissolution temperature of 40-90℃. The mass fraction of the polyvinyl alcohol fiber is 5-15% of the total mass of the three-dimensional fiber skeleton, and the angle between the extension direction of the dust removal channel and the grinding direction of the polishing disc is 15-45°. During the molding and curing process, the polyvinyl alcohol (PVA) fiber acts as a skeletal structure occupier. After dissolution and removal, it leaves regularly shaped channels. The geometry of the channels (diameter, direction, density) is controlled by the specifications and laying process of the PVA fiber, overcoming the inherent defects of random pore distribution and uncontrollable geometric parameters in traditional open skeletons. This achieves a structured design of the dust removal channel from a technological perspective. Specifically, the pore diameter of the directional dust removal channel is 0.1-0.5 mm, and the channel density is 20-60 channels / cm². 2 .

[0011] Preferably, the abrasive is at least one of silicon carbide or aluminum oxide. Silicon carbide is suitable for grinding non-ferrous metals and non-metallic materials, while aluminum oxide is suitable for ferrous materials.

[0012] Preferably, the abrasive has a bottom layer particle size of F100-F120 and a surface layer particle size of F60-F80. The gradient distribution of the coarse-grained layer (F60-F80) on top and the fine-grained layer (F100-F120) below allows the polishing disc to be dominated by coarse abrasive in the initial contact stage for rapid removal of excess material, and gradually transitions to fine abrasive to finish the surface as the use progresses, achieving progressive grinding of "coarse first, then fine", and the surface quality gradually improves within the service life of a single disc.

[0013] Preferably, the adhesive is a modified epoxy acrylate adhesive with a viscosity of 3000-8000 mPa·s, which ensures the wettability of the adhesive to the skeleton and the uniformity of the adhesive layer thickness.

[0014] On the other hand, the present invention also discloses the processing technology of the above-mentioned polishing sheet based on fiber skeleton, including the following steps: (1) Skeleton preparation: Surface-modified nylon fibers are mixed with soluble sacrificial fibers and laid in an orientation to form an open three-dimensional fiber skeleton preform; (2) Quantitative application of adhesive: Apply adhesive to the three-dimensional fiber skeleton preform; (3) Stepwise abrasive implantation: Abrasives are implanted into the surface of the three-dimensional fiber skeleton preform with adhesive applied in a gradient from fine to coarse; (4) Press plate forming: The skeleton after applying adhesive and sand is pressed for 10-30 min at a temperature of 120-160℃ and a pressure of 1.5-4.0 MPa to form an integral piece and obtain a rough polished sheet; (5) Channel formation: Immerse the coarse polishing sheet in a solvent for 20-60 min to dissolve and remove soluble sacrificial fibers, forming a directional dust removal channel; (6) Post-processing: Remove the rough polished sheet, dry it, and cool it to room temperature.

[0015] Preferably, in step (1), the surface modification is as follows: nylon fibers are immersed in an ethanol aqueous solution of 1-3% silane coupling agent for 30-60 min, and then cured in an oven at 80-100℃ for 1-2 h and cooled for later use; or low-temperature plasma treatment is used with a power of 100-300W and a time of 50-150s, and the working gas is air, nitrogen or argon with a gas flow rate of 20-80mL / min.

[0016] Preferably, in step (2), applying the adhesive to the three-dimensional fiber skeleton preform includes: Adhesive is applied to the three-dimensional fiber skeleton preform using precision rollers with a roller spacing of 0.3-1.0 mm and an adhesive application rate of 30-80 g / m². 2 .

[0017] Preferably, in step (3), the implantation of abrasives in a coarse-to-fine gradient on the surface of the three-dimensional fiber skeleton preform to which the adhesive is applied includes: Fine-grained abrasive with a surface density of 100-250 g / m² is first implanted onto the surface of the three-dimensional fiber skeleton preform with adhesive applied using a precision sandblasting machine. 2 Then, coarse-grained abrasive is implanted onto the surface of the fine-grained abrasive, with a surface density of 200-400 g / m². 2 .

[0018] The beneficial effects of this invention are as follows: (1) Nylon fiber modification enables the adhesive to be fixed to the fiber skeleton through chemical bonding. The abrasive is firmly held in the chemically bonded adhesive layer, resulting in a low abrasive shedding rate and reducing the attenuation rate of material removal per unit area after 60 minutes of continuous use.

[0019] (2) The combination of coarse and fine layers enables the polishing disc to integrate coarse and fine grinding, which can reduce the disc changing process and improve processing efficiency.

[0020] (3) By setting up a directional dust removal channel, the dust is actively discharged from the processing area, which prolongs the clogging time of the polishing disc under continuous processing conditions. Detailed Implementation

[0021] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0022] It should be noted that all reagents and raw materials used in this invention are commercially available, and the reagents are of analytical grade.

[0023] The nylon fiber is sourced from Yueyang Linlian Chemical Fiber Co., Ltd., product name Nylon 6, grade D1HA. The PVA fiber is sourced from Sinopec Sichuan Chemical Co., Ltd., model SS-7. The modified epoxy acrylate is sourced from Jiangsu Sanmu Group Co., Ltd., model 6100-D.

[0024] Example 1 This embodiment prepares a polishing disc with a gradient fiber skeleton using silicon carbide as the abrasive. The abrasive particle size combination is F80 (coarse-grained layer) / F100 (fine-grained layer). The preparation method is as follows: 1. Skeleton preparation and fiber modification Weigh 100g of nylon 6 (60D, fiber length 65mm), measure 2g of KH-550 and dissolve it in 200mL of 95% (v / v) ethanol aqueous solution. After stirring evenly, immerse the nylon 6 in the solution for 45 min at an immersion temperature of 25℃. Remove the nylon cotton, drain off the excess solution, and place it in a 90℃ forced-air oven to cure for 1.5 h. Cool to room temperature to obtain modified nylon fiber. Modified nylon fibers and PVA fibers were mixed at a mass ratio of 90:10 and laid on a web-laying machine to form a 350 mm × 350 mm × 6 mm precast skeleton. The PVA fibers were laid at a 25° angle to the plane of the skeleton, and the skeleton surface density was approximately 300 g / m². 2 .

[0025] 2. Apply adhesive in measured quantities The aforementioned precast skeleton was glued using a precision roller glue applicator. The roller spacing was set to 0.6 mm, the glue application rate was 0.8 m / min, and the adhesive used was modified epoxy acrylate (65% solids content, 5000 mPa·s viscosity). After application, the adhesive was weighed, and the glue application rate per unit area was 52 g / m². 2 .

[0026] 3. Step-by-step sand planting First layer (fine-grained layer): With the sizing surface of the skeleton facing upwards, apply F100 silicon carbide abrasive using a precision sander. The sander's vibration frequency is 50Hz, the conveyor belt speed is 0.5m / min, and the density of the fine-grained layer is controlled to 160g / m³. 2 This forms a bottom layer of fine sand. Second layer (coarse-grained layer): On the same sizing surface, continue applying F80 silicon carbide abrasive at a frequency of 50Hz and a speed of 0.5m / min. The density of the coarse-grained layer is controlled at 280g / m³. 2 This forms a coarse sand layer on the surface.

[0027] 4. Press plate forming After applying adhesive and sand, the skeleton is placed in a flat hot press. The platen temperature is set to 140℃, the pressure to 2.5 MPa, and the holding time to 20 min. The skeleton is pressed directly without turning over the cotton. After pressing, it is naturally cooled to 60℃ and demolded to obtain the polished sheet.

[0028] 5. PVA channel dissolution and post-treatment The molded polished sheet is immersed in 75℃ warm water for 40 minutes to fully dissolve the PVA fibers. After rinsing with clean water three times, it is placed in a 70℃ oven to dry for 3 hours. After cooling to room temperature, it is cut to the target size (150mm×100mm).

[0029] Example 2 This embodiment prepares a fiber skeleton polishing disc with alumina as the abrasive and a gradient distribution. The abrasive particle size combination is F60 (coarse-grained layer) / F100 (fine-grained layer). The preparation method is as follows: 1. Skeleton preparation and fiber modification Weigh 100g of nylon 6 (60D, fiber length 65mm), measure 1.5g of KH-550 and dissolve it in 150mL of 95% (v / v) ethanol aqueous solution. After stirring evenly, immerse the nylon 6 in the solution for 40min at an immersion temperature of 25℃. Remove the nylon cotton, drain off the excess solution, and place it in a 90℃ forced-air oven to cure for 1.5h. Cool to room temperature to obtain modified nylon fiber. Modified nylon fibers and PVA fibers were mixed at a mass ratio of 85:15 and laid on a web-laying machine to form a 350 mm × 350 mm × 6 mm precast skeleton. The PVA fibers were laid at a 30° angle to the plane of the skeleton, and the skeleton surface density was approximately 320 g / m². 2 .

[0030] 2. Apply adhesive in measured quantities The aforementioned precast skeleton was glued using a precision roller glue applicator. The roller spacing was set to 0.4 mm, the glue application rate was 0.8 m / min, and the adhesive used was modified epoxy acrylate. After glue application, the adhesive was weighed, and the glue application rate per unit area was 75 g / m². 2 .

[0031] 3. Step-by-step sand planting First layer (fine-grained layer): With the sizing surface of the skeleton facing upwards, apply F100 alumina abrasive using a precision sander. The sander's vibration frequency is 50Hz, the conveyor belt speed is 0.5m / min, and the density of the fine-grained layer is controlled to 220g / m³. 2 This forms a bottom layer of fine sand. Second layer (coarse-grained layer): On the same adhesive application surface, continue to apply F60 alumina abrasive at a frequency of 50Hz and a speed of 0.5m / min. The density of the coarse-grained layer is controlled at 370g / m³. 2 This forms a coarse sand layer on the surface.

[0032] 4. Press plate forming After applying adhesive and sand, the skeleton is placed in a flat hot press. The platen temperature is set to 150℃, the pressure to 3.0 MPa, and the holding time to 15 min. The skeleton is pressed directly without turning over the cotton. After pressing, it is naturally cooled to 55℃ and then demolded to obtain the polished sheet.

[0033] 5. PVA channel dissolution and post-treatment The molded polished sheet is immersed in 78℃ warm water for 35 minutes to fully dissolve the PVA fibers. After rinsing with clean water three times, it is placed in a 75℃ oven to dry for 2.5 hours. After cooling to room temperature, it is cut to the target size (150mm×100mm).

[0034] Example 3 This embodiment prepares a polishing disc with a gradient fiber skeleton using silicon carbide as the abrasive. The abrasive grain size combination is F80 (coarse-grained layer) / F120 (fine-grained layer). The preparation method is as follows: 1. Skeleton preparation and fiber modification Weigh 100g of Nylon 6 (80D, fiber length 65 mm), measure 0.9g of KH-550 and dissolve it in 150mL of 95% (v / v) ethanol aqueous solution. After stirring evenly, immerse Nylon 6 in the solution for 35min at an immersion temperature of 25℃. Remove the nylon cotton, drain off excess solution, and place it in an 80℃ forced-air oven for 2h to cure. Cool to room temperature to obtain modified nylon fiber. Modified nylon fibers and PVA fibers were mixed at a mass ratio of 95:5 and laid on a web-laying machine to form a 350 mm × 350 mm × 6 mm precast skeleton. The PVA fibers were laid at a 20° angle to the plane of the skeleton, and the skeleton surface density was approximately 280 g / m². 2 .

[0035] 2. Apply adhesive in measured quantities The aforementioned precast skeleton was glued using a precision roller glue applicator. The roller spacing was set to 0.9 mm, the glue application rate was 0.8 m / min, and the adhesive used was modified epoxy acrylate. After glue application, the adhesive was weighed, and the glue application rate per unit area was 35 g / m². 2 .

[0036] 3. Step-by-step sand planting First layer (fine-grained layer): With the sizing surface of the skeleton facing upwards, apply F120 silicon carbide abrasive using a precision sander. The sander's vibration frequency is 50Hz, the conveyor belt speed is 0.5m / min, and the density of the fine-grained layer is controlled to 110g / m³. 2 This forms a bottom layer of fine sand. Second layer (coarse-grained layer): On the same sizing surface, continue applying F80 silicon carbide abrasive at a frequency of 50Hz and a speed of 0.5m / min. The density of the coarse-grained layer is controlled at 210g / m³. 2 This forms a coarse sand layer on the surface.

[0037] 4. Press plate forming After applying adhesive and sand, the skeleton is placed in a flat hot press. The platen temperature is set to 125℃, the pressure to 1.8 MPa, and the holding time to 28 min. The skeleton is pressed directly without turning over the cotton. After pressing, it is naturally cooled to 50℃ and then demolded to obtain the polished sheet.

[0038] 5. PVA channel dissolution and post-treatment The molded polished sheet is immersed in 70℃ warm water for 55 minutes to fully dissolve the PVA fibers. After rinsing with clean water three times, it is placed in a 65℃ oven to dry for 3.5 hours. After cooling to room temperature, it is cut to the target size (150mm×100mm).

[0039] Example 4 This embodiment prepares a fiber skeleton polishing disc with a gradient distribution of a silicon carbide and alumina (mass ratio 1:1) mixture as abrasive. The abrasive particle size combination is F60 (coarse-grained layer) / F120 (fine-grained layer). The preparation method is as follows: 1. Skeleton preparation and fiber modification 100g of nylon 6 (60D, fiber length 65 mm) was weighed and placed in a low-temperature plasma device. It was treated for 90s under a nitrogen atmosphere (flow rate 60 mL / min) and a power of 200 W. Polar functional groups were introduced on the fiber surface by high-energy particle bombardment and micro-etching was formed, which improved the chemical bonding ability with the adhesive and obtained modified nylon fiber. Modified nylon fibers and PVA fibers were mixed at a mass ratio of 88:12 and laid on a web-laying machine to form a 350 mm × 350 mm × 6 mm precast skeleton. The PVA fibers were laid at a 40° angle to the plane of the skeleton, and the skeleton surface density was approximately 310 g / m³. 2 .

[0040] 2. Apply adhesive in measured quantities The aforementioned precast skeleton was glued using a precision roller glue applicator. The roller spacing was set to 0.7 mm, the glue application rate was 0.8 m / min, and the adhesive used was modified epoxy acrylate. After application, the glue was weighed, and the glue application rate per unit area was 60 g / m². 2 .

[0041] 3. Step-by-step sand planting First layer (fine-grained layer): With the sizing surface of the skeleton facing upwards, apply sand using an F120 mixed abrasive through a precision sander. The sander's vibration frequency is 50Hz, the conveyor belt speed is 0.5m / min, and the density of the fine-grained layer is controlled to 190g / m³. 2 This forms a bottom layer of fine sand. Second layer (coarse-grained layer): Continue applying F60 mixed abrasive to the same adhesive surface at a frequency of 50Hz and a speed of 0.5m / min. The density of the coarse-grained layer is controlled at 340g / m³. 2 This forms a coarse sand layer on the surface.

[0042] 4. Press plate forming After applying adhesive and sand, the skeleton is placed in a flat hot press. The platen temperature is set to 145℃, the pressure to 2.8 MPa, and the holding time to 22 min. The skeleton is pressed directly without turning over the cotton. After pressing, it is naturally cooled to 56℃ and then demolded to obtain the polished sheet.

[0043] 5. PVA channel dissolution and post-treatment The molded polished sheet is immersed in 75℃ warm water for 30 minutes to fully dissolve the PVA fibers. After rinsing with clean water three times, it is placed in a 72℃ oven to dry for 3 hours. After cooling to room temperature, it is cut to the target size (150mm×100mm).

[0044] Comparative Example 1 Compared with Example 1, the difference is that step 1 does not include the fiber modification step, that is, step 1 directly mixes and lays the nylon fiber and PVA fiber together.

[0045] Comparative Example 2 Compared with Example 1, the difference is that PVA fibers are not introduced in step 1, and modified nylon fibers are directly laid into a web to form a skeleton prepolymer.

[0046] Comparative Example 3 Compared with Example 1, the difference is that: the integral impregnation method is used for sand planting, and steps 2 and 3 are combined into one step, that is, the skeleton preform (without PVA fiber) is immersed in F80 silicon carbide (150g / m²). 2 ) and F100 silicon carbide (90g / m 2 Immerse the entire mixture in the adhesive solution of the mixed abrasive for 30 minutes, then remove and drain off the excess solution.

[0047] Comparative Example 4 Compared with Example 1, the difference is that step 4 adopts cotton-turning and layering pressing: after the two skeletons with glue and sand are stacked together, the cotton is turned over (the inner sides face each other), and pressed at 140℃ and 2.5MPa for 20 minutes.

[0048] Comparative Example 5 The difference compared to Example 1 is that the abrasive in step 3 is not gradient-distributed, i.e., F80 silicon carbide (area density 280 g / m²) is used. 2 ) and F100 silicon carbide (area density 160g / m³) 2 After mixing, the abrasive is uniformly implanted into the skeleton in a single pass using a precision abrasive applicator, with a total abrasive surface density of 440 g / m³. 2 A layered structure without coarse / fine granular layers.

[0049] The polished wafer samples prepared in Examples 1-4 and Comparative Examples 1-5 were subjected to relevant performance tests. The test indicators and methods are as follows: (1) Thickness deviation and coefficient of variation (CV) of abrasive surface density: Thickness deviation: Determined according to GB / T 24218.2-2009 "Textiles - Test Methods - Part 2: Determination of Thickness". After the polished sheet is conditioned to humidity equilibrium under standard atmospheric conditions, five test points are evenly selected on the sample surface, and a thickness tester (presser foot area ≥ 20 cm²) is used. 2 The thickness was measured at each point under a pressure of 2 kPa. The thickness deviation was defined as the maximum difference between the measured thickness and the nominal thickness at each measuring point.

[0050] CV: According to GB / T 24218.1-2009 "Textiles - Test Methods - Part 1: Determination of Mass per Unit Area", cut a 100cm section. 2 Ten samples were tested, and the areal density (g / m³) of each sample was measured using an electronic balance. 2 The coefficient of variation (CV) for 10 samples is calculated as: CV = standard deviation / mean × 100%. The smaller the CV value, the better the uniformity of sand planting.

[0051] (2) Interlayer peel strength: The interlayer bonding strength was determined by T-type peel test according to GB / T 2791-1995 "Test method for T-peel strength of adhesives, flexible materials to flexible materials". The sample was 25mm×200mm, the tensile rate was 100mm / min, and the average value of 5 measurements was taken. The unit is N / cm.

[0052] (3) Porosity: The porosity of the skeleton was determined in accordance with GB / T 21650.1-2008 "Determination of Pore Size Distribution and Porosity of Solid Materials by Mercury Intrusion Porosimetry and Gas Adsorption Method". The average value of 3 measurements was taken.

[0053] (4) Material removal rate (MRR) and attenuation rate: The test was conducted in accordance with the principle of JB / T 10155-2012 "Test Method for Grinding Performance of Coated Abrasives, Abrasive Cloth and Abrasive Paper": The grinding linear speed of the test machine was 22 m / s, the workpiece was 45# steel (hardness HRC 40~45), the normal pressure was 5 N, and the grinding was carried out continuously for 60 min. The weight loss of the workpiece was measured every 10 min. The average MRR of the initial 10 min was used as the reference value, and the average MRR of the last 10 min (50~60 min) was used as the final value. The attenuation rate = (reference value - final value) / reference value × 100%.

[0054] (5) Blocking time: Refer to ISO 3002-4:1984 "Basic parameters of cutting and grinding - Part 4: force, energy and power", under the grinding conditions of test index (4), continuously monitor the normal grinding force; the grinding time corresponding to the grinding force increasing by 10% from the initial value is defined as the blocking time (min).

[0055] (6) Initial grinding efficiency (g / min): The average material removal rate during the first 5 min of grinding time was measured according to the grinding conditions of the test index (4), in mg / min.

[0056] (7) Abrasive shedding rate: The polishing disc was ultrasonically vibrated (40 kHz, 5 min) without external force, and the mass difference before and after was weighed. The ratio of the mass of abrasive shedding to the initial mass of abrasive was calculated (%).

[0057] The performance test results are shown in Table 1.

[0058] Table 1 Performance Test Results

[0059] As shown in Table 1, Examples 1-4 of the present invention outperform the comparative examples in key indicators such as open area ratio, interlayer peel strength, thickness consistency, grinding efficiency retention rate, clogging time, and abrasive shedding rate, as detailed below: (1) Effect of KH-550 modification: The abrasive shedding rate of Comparative Example 1 was 11.3%, which was significantly higher than that of Example 1 (3.7%), indicating that the chemical bonding interface formed by KH-550 modification effectively improved the abrasive's fixation strength. In addition, the MRR decay rate of Comparative Example 1 reached 29.6%, while that of Example 1 was only 12.3%, further illustrating that the improvement in abrasive retention rate directly translates into improved grinding stability.

[0060] (2) Function of directional dust removal channel: Comparative Example 2 had no PVA channel, and its skeleton opening rate was 53%, lower than 68% in Example 1, indicating that the skeleton was further compacted during the pressing process when there was no sacrificial fiber occupation. The clogging time of Comparative Example 2 was only 24 min, while that of Example 1 was 68 min, an extension of more than 2 times, verifying the significant contribution of directional dust removal channel to dust removal efficiency. The initial MRR of the two were similar (187 vs 185 mg / min), but the MRR decay rate was significantly different (12.3% vs 33.7%), indicating that the improvement of dust removal by directional dust removal channel directly affects the performance maintenance of long-term grinding, rather than affecting the initial grinding efficiency.

[0061] (3) Effect of stepwise abrasive coating: The abrasive CV value of Comparative Example 3 was 22.6%, which was much higher than that of Example 1 (6.2%), directly reflecting the extremely uneven distribution of abrasive in the overall impregnation method; the initial MRR (149 mg / min) and clogging time (19 min) were both the lowest, indicating that uneven distribution led to a reduction in the effective grinding contact area and accelerated clogging due to local overload. The stepwise quantitative abrasive coating process of this invention has a significant advantage in abrasive distribution uniformity.

[0062] (4) Effect of non-returning process: The interlayer peel strength of the cotton-returning process in Comparative Example 4 was only 6.3 N / cm, lower than 9.5 N / cm in Example 1, indicating that the cotton-returning operation caused some disturbance to the interlayer bonding surface; the more significant difference was reflected in the thickness deviation: 0.16 mm in Comparative Example 4 and 0.07 mm in Example 1, with obvious differences in thickness consistency, affecting the grinding uniformity of batch products. The difference in grinding performance (MRR attenuation rate 13.1% vs 12.3%) was small, indicating that the main impact of the cotton-returning process was on the consistency of product structure.

[0063] (5) Effect of gradient distribution: The initial MRR of Comparative Example 5 was 192 mg / min, which was close to that of Example 1 (187 mg / min), indicating that gradient stratification had little effect on the initial grinding rate. However, the MRR decay rate of Comparative Example 5 was as high as 28.4%, which was much higher than that of Example 1 (12.3% decay rate), the clogging time was only 36 min (68 min in Example 1, a reduction of 47%), and the abrasive CV value was 6.8% (6.2% for the fine-grained layer in Example 1). The fundamental reason for the above differences lies in the following: Under non-gradient distribution conditions, coarse and fine abrasives are randomly mixed on the same plane. In the early stages of grinding, coarse abrasives are fully exposed, and the initial MRR is acceptable. However, as the grinding process progresses, fine abrasives cannot effectively replace coarse abrasives for finishing grinding. The continuous dominance of coarse abrasives in cutting leads to larger chip sizes, higher dust generation rates, and wider particle size distribution, making the dust removal channel prone to bridging blockage. At the same time, the wear rates of coarse and fine particles in the mixed abrasives are asynchronous. After the fine particles fail prematurely, local under-grinding zones are formed, exacerbating uneven grinding force and attenuation. The gradient structure realizes a progressive functional partitioning from coarse to fine grinding. The abrasive particle size of each stage matches the cutting task, fundamentally extending the effective grinding cycle. The clogging time (68 min) of Example 1 is 89% lower than that of Comparative Example 5, and the MRR attenuation rate is reduced by 56.5%, fully verifying the effect of gradient abrasive distribution on the sustainability of grinding performance.

[0064] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0065] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A polishing disc based on a fiber skeleton, characterized in that, include: A three-dimensional fiber skeleton composed of surface-modified nylon fibers; An adhesive layer chemically bonded to the surface of the modified nylon fiber; Abrasive particles evenly distributed in the adhesive layer; And directional dust removal channels distributed within the three-dimensional fiber skeleton; The directional dust removal channel is formed by dissolving and removing soluble sacrificial fibers with a solvent after molding; The abrasive is distributed in a gradient from fine to coarse on the three-dimensional fiber skeleton.

2. The polishing disc based on a fiber skeleton according to claim 1, characterized in that, The modified nylon fibers are treated with silane coupling agents or plasma treatment.

3. The polishing disc based on a fiber skeleton according to claim 1, characterized in that, The soluble sacrificial fiber is polyvinyl alcohol fiber with a dissolution temperature of 40-90℃. The mass fraction of the polyvinyl alcohol fiber is 5-15% of the total mass of the three-dimensional fiber skeleton. The angle between the extension direction of the dust discharge channel and the grinding direction of the polishing disc is 15-45°.

4. The polishing disc based on a fiber skeleton according to claim 1, characterized in that, The abrasive is at least one of silicon carbide or aluminum oxide.

5. The polishing disc based on a fiber skeleton according to claim 1, characterized in that, The abrasive has a bottom layer particle size of F100-F120 and a surface layer particle size of F60-F80.

6. The polishing disc based on a fiber skeleton according to claim 1, characterized in that, The adhesive is a modified epoxy acrylate adhesive with a viscosity of 3000-8000 mPa·s.

7. A processing method for a polishing disc based on a fiber skeleton according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Skeleton preparation: Surface-modified nylon fibers are mixed with soluble sacrificial fibers and laid in an orientation to form an open three-dimensional fiber skeleton preform; (2) Quantitative application of adhesive: Apply adhesive to the three-dimensional fiber skeleton preform; (3) Stepwise abrasive implantation: Abrasives are implanted into the surface of the three-dimensional fiber skeleton preform with adhesive applied in a gradient from fine to coarse; (4) Press plate forming: The skeleton after applying adhesive and sand is pressed for 10-30 min at a temperature of 120-160℃ and a pressure of 1.5-4.0 MPa to form an integral piece and obtain a rough polished sheet; (5) Channel formation: Immerse the coarse polishing sheet in a solvent for 20-60 min to dissolve and remove soluble sacrificial fibers, forming a directional dust removal channel; (6) Post-processing: Remove the rough polished sheet, dry it, and cool it to room temperature.

8. The processing technology of the polishing disc based on the fiber skeleton according to claim 7, characterized in that, In step (1), the surface modification is as follows: nylon fibers are immersed in an ethanol aqueous solution of 1-3% silane coupling agent for 30-60 min, and then cured in an oven at 80-100℃ for 1-2 h and cooled for later use; or low-temperature plasma treatment is used with a power of 100-300W and a time of 50-150s, and the working gas is air, nitrogen or argon with a gas flow rate of 20-80mL / min.

9. The processing technology of the polishing disc based on the fiber skeleton according to claim 7, characterized in that, In step (2), applying the adhesive to the three-dimensional fiber skeleton preform includes: Adhesive is applied to the three-dimensional fiber skeleton preform using precision rollers with a roller spacing of 0.3-1.0 mm and an adhesive application rate of 30-80 g / m². 2 .

10. The processing technology of the polishing disc based on the fiber skeleton according to claim 7, characterized in that, In step (3), the implantation of abrasives in a coarse-to-fine gradient on the surface of the three-dimensional fiber skeleton preform with applied adhesive includes: Fine-grained abrasive with a surface density of 100-250 g / m² is first implanted onto the surface of the three-dimensional fiber skeleton preform with adhesive applied using a precision sandblasting machine. 2 Then, coarse-grained abrasive is implanted onto the surface of the fine-grained abrasive, with a surface density of 200-400 g / m². 2 .

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