High-wear-resistance polytetrafluoroethylene sealing ring and preparation method thereof

Abstract

The invention discloses a high-wear-resistance polytetrafluoroethylene sealing ring and a preparation method thereof, and belongs to the technical field of sealing rings. The invention relates to a high-wear-resistance polytetrafluoroethylene sealing ring, which is prepared from the following components in parts by mass: 100 parts of polytetrafluoroethylene resin (PTFE); 3 parts of nano silicon dioxide (SiO2); 5 parts of graphite powder; 10 parts of chopped carbon fiber; 1 part of a molybdenum disulfide (MoS2) solid lubricant; and 2 parts of polyether-ether-ketone (PEEK) micro powder. The nano silicon dioxide is subjected to surface hydroxylation treatment and then is grafted with the coupling agent, so that the affinity and dispersity of the nano silicon dioxide in a PTFE matrix are improved, the agglomeration phenomenon is avoided, and uniform reinforced phase distribution is formed, thereby ensuring the consistency of the performance of the material.

Description

Technical Field

[0001] This invention relates to the field of sealing ring technology, and more specifically, to a high wear-resistant polytetrafluoroethylene sealing ring and its preparation method. Background Technology

[0002] Polytetrafluoroethylene (PTFE) is widely used in sealing rings, gaskets, and bearing components in machinery, chemical, aerospace, and automotive industries due to its excellent corrosion resistance, high temperature resistance, and self-lubricating properties. However, traditional pure PTFE materials have significant shortcomings, especially poor wear resistance and insufficient creep resistance. Under long-term friction and high pressure conditions, it is prone to deformation and failure, leading to decreased sealing performance and shortened service life.

[0003] To improve the wear resistance and mechanical properties of PTFE, existing technologies typically employ filler modification methods, such as adding inorganic fillers like glass fiber, graphite, and bronze powder, to enhance the material's strength and wear resistance. However, these modification methods have the following drawbacks: Inorganic fillers are unevenly distributed within the PTFE matrix, easily forming agglomerates and leading to significant local performance differences, thus affecting overall mechanical and sealing performance. Poor interfacial compatibility between the filler and PTFE can easily result in microcracks or detachment at the interface, weakening the reinforcing and wear-resistant effects. Traditional fillers have limited effect on reducing the friction coefficient of PTFE and cannot significantly solve wear problems under high-speed, heavy-load conditions.

[0004] Therefore, there is an urgent need for a modification scheme that can significantly improve the wear resistance and interfacial bonding of PTFE, especially by surface modification of nanofillers and fiber reinforcement materials to improve dispersibility and interfacial bonding, and by combining with optimized molding and sintering processes, so as to prepare highly wear-resistant PTFE sealing rings to meet the long-term stable use requirements under harsh working conditions. Summary of the Invention

[0005] The purpose of this invention is to provide an antibacterial water-based ink and its preparation method to solve the problems mentioned in the background art.

[0006] A high wear-resistant polytetrafluoroethylene sealing ring, comprising the following components by weight: Polytetrafluoroethylene resin (PTFE): 100 parts; Nano-silica (SiO2): 3 parts; Graphite powder: 5 parts; Short-cut carbon fiber: 10 parts; Molybdenum disulfide (MoS2) solid lubricant: 1 part; Polyetheretherketone (PEEK) micro powder: 2 parts.

[0007] Preferably, nano-Si The surface functionalization process includes the following steps: Nano-SiO2 was dispersed in an ethanol-water mixed solution (volume ratio 1:1) and stirred at 300 rpm for 30 minutes using a mechanical stirrer. Add 3% by weight of 3-aminopropyltriethoxysilane (APTES) to the dispersion and stir for 1.5 hours; Adjust the pH of the solution to 4.5 with dilute acetic acid; The precipitate was separated by centrifugation at 5000 rpm for 10 minutes and then washed three times with ethanol. Functionalized nano-SiO2 powder was obtained by drying in an oven at 70℃ for 4 hours.

[0008] Preferably, the coupling agent treatment process for chopped carbon fibers includes: Short carbon fibers are immersed in an ethanol solution, and 2% by weight of APTES coupling agent is added. Stir for 1.5 hours in an oil bath at 85°C; After the reaction, filter and wash three times with ethanol. The treated short-cut carbon fibers were obtained by drying in an oven at 70°C for 4 hours.

[0009] Preferably, the graphite powder is ball-milled before being added to the mixture for 2 hours, and the particle size distribution is controlled within 10μm±2μm.

[0010] Preferably, the PEEK micro powder is obtained by spray drying at a temperature of 140°C, with the particle size distribution controlled at 10μm±2μm.

[0011] Preferably, the fillers are added to PTFE in the following order: first functionalized nano-SiO2, then short-cut carbon fibers, followed by graphite powder, MoS2 solid lubricant and PEEK micro powder.

[0012] A method for preparing a high wear-resistant polytetrafluoroethylene sealing ring includes the following steps: S1. Mix PTFE resin with the treated nano-SiO2, carbon fiber, graphite powder, MoS2 solid lubricant and PEEK micro powder as described in claims 2–6 in a certain proportion; S2. Add the mixture to deionized water, stir with a mechanical stirrer at 400 rpm for 10 minutes, and then sonicate with an ultrasonic processor for 10 minutes to fully disperse the components, keeping the temperature at 30–35℃. S3. Spray dry the wet dispersion at an inlet temperature of 140℃ and an outlet temperature of 85℃ to obtain dry powder with a moisture content of ≤1%; S4. Dry mix the dry powder under high shear for 5 minutes to ensure uniform distribution of the filler; S5. Compress or extrude the dry mixture obtained in S4 into sealing ring blanks; S6. Segmented heating sintering is carried out under nitrogen protection. The pre-firing stage temperature is 310℃ and held for 0.5 hours. The main firing stage temperature is 370℃ and held for 3 hours. The nitrogen flow rate is controlled at 0.8L / min during the sintering process to prevent oxidation. S7. Perform microstructure surface treatment on the sintered sealing ring: Micro-blasting, pressure 0.4MPa, blasting time 2 minutes; Laser microtexturing, laser energy density 0.8 J / cm², scanning speed 5 mm / s.

[0013] Preferably, wet dispersion and ultrasonic treatment are used in combination to ensure that the nano-SiO2 powder is broken up and the short-cut carbon fibers are evenly distributed.

[0014] Preferably, the dry mixture tableting pressure is 50 MPa and the extrusion speed is 10 mm / s.

[0015] Preferably, the microstructure surface treatment uses only a combination of micro-blasting and laser micro-texturing.

[0016] Compared with the prior art, the advantages of this invention are: (1) By performing surface hydroxylation treatment on nano-silica and then grafting coupling agent, its affinity and dispersibility in the PTFE matrix are improved, agglomeration is avoided, and a uniform distribution of reinforcing phase is formed, thereby ensuring the consistency of material properties.

[0017] (2) By acidifying the short carbon fibers and further grafting coupling agents, the interfacial bonding force between the carbon fibers and the PTFE matrix is ​​effectively improved, the interfacial peeling and microcrack generation are significantly reduced, and the structural stability of the material is guaranteed under long-term friction environment.

[0018] (3) The surface-modified nano-silica and carbon fiber work together to reduce the friction coefficient of the material and enhance the load-bearing capacity, so that the sealing ring can maintain excellent wear resistance under high speed, heavy load and long-term friction conditions.

[0019] (4) After adding treated nanofillers and carbon fibers, the prepared composite material has significantly improved hardness, compressive strength and creep resistance compared with traditional filled modified PTFE, which solves the problem of easy deformation of sealing ring under high pressure.

[0020] (5) In typical friction and wear tests, the wear rate of the PTFE sealing ring prepared in the embodiments of the present invention is significantly lower than that of conventional filled modified PTFE products, and the service life is extended by more than 30%, which can better meet the long-term reliable operation requirements of mechanical equipment in extreme environments. Detailed Implementation

[0021] A method for preparing a high wear-resistant polytetrafluoroethylene sealing ring

[0022] 1. Raw material preparation

[0023] Polytetrafluoroethylene resin (PTFE): purchased from Shanghai Sanai Fu New Material Co., Ltd., model DF-3, purity ≥99.9%, average particle size 25μm; Nano silica: purchased from Nanjing Zhuoyue Nanotechnology Co., Ltd., initial particle size 30nm; 3-Aminopropyltriethoxysilane (APTES): analytical grade, purchased from Sinopharm Chemical Reagent Co., Ltd.; Short-cut carbon fiber: purchased from Toray Industries, Ltd., 200μm in length and 7μm in diameter; Graphite powder: purchased from Qingdao Marine Carbon Materials Co., Ltd., with an initial average particle size of 30μm; Molybdenum disulfide: purchased from Sinopharm Reagent, purity ≥99.5%; Polyetheretherketone (PEEK) micro powder: purchased from Victrex, UK, with a particle size ≤20μm.

[0024] Nano-SiO2 surface functionalization treatment

[0025] 5g of nano-SiO2 was dispersed in 100mL of ethanol-water mixture (volume ratio 1:1) and stirred at 300rpm for 30 minutes using a mechanical stirrer. Add 0.15g APTES (3% of the mass of SiO2) to the solution and continue stirring for 1.5 hours; Adjust the pH to 4.5 with dilute acetic acid and let it stand for 30 minutes to react; Collect the precipitate by centrifugation at 5000 rpm for 10 minutes and wash it three times with anhydrous ethanol. The surface-aminated silica powder was obtained by drying in a forced-air oven at 70°C for 4 hours.

[0026] Surface coupling agent treatment of chopped carbon fibers

[0027] Weigh 10g of short-cut carbon fibers, immerse them in 500mL of ethanol solution, and add 0.2g of APTES (2% of the fiber mass). Stir in an oil bath at 85°C for 1.5 hours; After the reaction was complete, the mixture was filtered and washed three times with ethanol. The treated carbon fibers were dried in a 70℃ oven for 4 hours to obtain surface-modified carbon fibers.

[0028] Graphite Powder Ball Mill

[0029] 5g of graphite powder was placed in an agate ball mill and ball-milled at 300rpm for 2 hours to obtain graphite powder with a particle size distribution of 10μm±2μm.

[0030] PEEK micro powder preparation

[0031] The PEEK particle solution was spray-dried at an inlet temperature of 140℃ and an outlet temperature of 85℃ to obtain PEEK micro powder with an average particle size of 10μm±2μm.

[0032] Mixed dispersion

[0033] Weigh out proportionally: PTFE 100g Functionalized nano silica 3g 10g of modified short-cut carbon fiber 5g of ball-milled graphite powder 1g of MoS2 powder 2g of PEEK micro powder Add the following ingredients in sequence: first SiO2, then carbon fiber, followed by graphite powder, MoS2, and PEEK.

[0034] Add 200 mL of deionized water and stir mechanically at 400 rpm for 10 minutes; Then use an ultrasonic processor to sonicate for 10 minutes (power 400W), keeping the temperature at 30–35℃.

[0035] Spray drying and dry mixing

[0036] The wet dispersion was spray-dried at an inlet temperature of 140℃ and an outlet temperature of 85℃, resulting in a powder with a moisture content of ≤1%. The dry powder is subjected to high-shear mixing (3000 rpm) for 5 minutes to ensure uniform dispersion of the filler.

[0037] Forming and sintering

[0038] The mixed powder is molded into a ring-shaped blank under a molding pressure of 50 MPa. Sintering was carried out under a nitrogen atmosphere. Preheating stage: 310℃, hold for 0.5 hours; Main heating stage: 370℃, keep warm for 3 hours; The nitrogen flow rate was maintained at 0.8 L / min during the sintering process.

[0039] Surface microstructure treatment

[0040] A combined surface treatment is performed on the sintered sealing ring: Micro-blasting: blasting pressure 0.4MPa, time 2 minutes; Laser microtexturing: energy density 0.8 J / cm², scanning speed 5 mm / s.

[0041] Example 2

[0042] A method for preparing a high wear-resistant polytetrafluoroethylene sealing ring

[0043] Raw material preparation

[0044] Polytetrafluoroethylene resin (PTFE): purchased from Shanghai Sanai Fu New Material Co., Ltd., model DF-3, purity ≥99.9%, average particle size 25μm; Nano-silica (SiO2): Purchased from Nanjing Zhuoyue Nanotechnology Co., Ltd., with an initial particle size of 25nm; 3-Methacryloxypropyltrimethoxysilane (KH-570): analytical grade, purchased from Aladdin Reagents; Short-cut carbon fiber: purchased from Toray Industries, Inc., 150 μm in length and 7 μm in diameter; Graphite powder: purchased from Qingdao Marine Carbon Materials Co., Ltd., with an initial average particle size of 20μm; Molybdenum disulfide (MoS2): Purchased from Sinopharm Reagent, purity ≥99.5%; Polyetheretherketone (PEEK) micro powder: purchased from Victrex, UK, with a particle size ≤15μm.

[0045] Nano-SiO2 surface functionalization treatment

[0046] Disperse 5g of nano-SiO2 in 100mL of anhydrous ethanol and sonicate for 15 minutes. Add 0.25g KH-570 (5% of the mass of SiO2) to the solution and stir at 400rpm for 2 hours on a magnetic stirrer; Adjust the pH to 5.0 with dilute hydrochloric acid and continue the reaction for 30 minutes; Centrifuge at 5000 rpm for 10 minutes, collect the precipitate, and wash three times with ethanol; The SiO2 powder with surface methacrylamide was obtained by drying in a vacuum oven at 80°C for 6 hours.

[0047] Surface coupling agent treatment of chopped carbon fibers

[0048] Weigh 10g of chopped carbon fiber, immerse it in 500mL of deionized water, and add 0.3g of KH-560 (epoxysilane coupling agent, accounting for 3% of the fiber mass). Stir for 2 hours in an oil bath at 90℃; After the reaction, the mixture was filtered and washed three times with distilled water. Carbon fibers with surface epoxidation were obtained by drying in an 80°C forced-air oven for 6 hours.

[0049] Graphite Powder Ball Mill

[0050] Place 5g of graphite powder in a planetary ball mill and ball mill at 400rpm for 3 hours, controlling the particle size distribution to 8μm±2μm.

[0051] PEEK micro powder preparation

[0052] PEEK particles were pulverized by high-speed airflow and then spray-dried at an inlet temperature of 150°C and an outlet temperature of 90°C to obtain PEEK micro powder with an average particle size of 8μm±2μm.

[0053] Mixed dispersion

[0054] Weigh out the following proportions: 100g PTFE, functionalized Si 3g, modified carbon fiber 10g, ball-milled graphite powder 5g, Mo 1g, PEEK micro powder 2g.

[0055] The following steps are taken sequentially: PTFE → SiO2 → carbon fiber → graphite powder → MoS2 → PEEK; Add 200 mL of deionized water and stir mechanically at 400 rpm for 10 minutes; The ultrasonic processor is used for 15 minutes of ultrasonic treatment (power 450W), and the temperature is maintained at 30–35℃.

[0056] Spray drying and dry mixing

[0057] Spray drying: inlet temperature 150℃, outlet temperature 90℃, dry powder moisture content ≤0.8%; High-shear dry mixing at 3000 rpm for 5 minutes.

[0058] Forming and sintering

[0059] Compression molding pressure: 55 MPa; Sintering conditions: 310℃ for 0.5 hours, 375℃ for 3 hours; Nitrogen flow rate: 1.0 L / min.

[0060] Surface microstructure treatment

[0061] Micro-blasting: blasting pressure 0.45MPa, time 3 minutes; Laser microtexturing: energy density 0.9 J / cm², scanning speed 4 mm / s.

[0062] Example 3

[0063] A method for preparing a high wear-resistant polytetrafluoroethylene sealing ring

[0064] Raw material preparation

[0065] PTFE: Shanghai Sanaifu, model DF-2, average particle size 20μm; Nano SiO2: Beijing Dingguo Nanotechnology Co., Ltd., particle size 40nm; γ-glycidoxypropyltrimethoxysilane (GPTMS, KH-560), analytical grade; Short-cut carbon fiber: Toray Industries, Inc., 300μm in length; Graphite powder: Qingdao Marine Carbon Materials Co., Ltd., initial particle size 40μm; MoS2: Guoyao Reagent, purity ≥99.8%; PEEK micro powder: Victrex, particle size ≤12μm.

[0066] Nano-SiO2 functionalization

[0067] 5g of SiO2 was dispersed in 100mL of toluene and sonicated for 20 minutes. Add 0.2g GPTMS (4% by weight), and reflux in an oil bath at 80°C for 2 hours; After cooling, the reaction solution was centrifuged and washed three times with toluene. The surface epoxidized SiO2 was obtained by drying in a vacuum oven at 70°C for 5 hours.

[0068] Short-cut carbon fiber processing

[0069] 10g of carbon fiber was pre-soaked in 60% nitric acid solution for 1 hour for surface activation, and then washed with pure water until neutral. Then add 0.2g KH-550 (aminosilane coupling agent, 2% by weight) to ethanol and stir at 80°C for 1.5 hours; Filter by suction, wash with ethanol, and dry at 80°C for 6 hours.

[0070] Graphite powder treatment

[0071] The ball milling time was 2.5 hours, and the particle size distribution was controlled within 12μm±2μm.

[0072] PEEK micro powder preparation

[0073] PEEK particles were dissolved and then spray-dried at an inlet temperature of 145℃ and an outlet temperature of 88℃, with an average particle size of 9μm±1.5μm.

[0074] Mixed dispersion

[0075] Formula: PTFE 100g, SiO2 3g, carbon fiber 10g, graphite powder 5g, MoS2 1g, PEEK 2g; Add 250mL of deionized water, mechanically stir at 500rpm for 12 minutes, and sonicate for 12 minutes (power 420W).

[0076] Drying and mixing

[0077] The spray dryer has an inlet temperature of 145°C and an outlet temperature of 88°C. High-shear mixing (2800 rpm, 6 minutes).

[0078] Forming and sintering

[0079] Compression molding pressure 60MPa; Sintering: Pre-fire at 320℃ for 0.5 hours, then main firing at 380℃ for 3 hours; Nitrogen flow rate: 0.9 L / min.

[0080] Surface treatment

[0081] Micro-blasting: 0.5MPa, 3 minutes; Laser microtexturing: 1.0 J / cm², scanning speed 6 mm / s.

[0082] Example 4

[0083] A method for preparing a high wear-resistant polytetrafluoroethylene sealing ring

[0084] Raw material preparation

[0085] PTFE: Sanaifu, model DF-4, average particle size 30μm; Nano SiO2: Nanjing Zhuoyue Nanotechnology Co., Ltd., particle size 20nm; Silane coupling agent KH-792 (aminopropyltrimethoxysilane); Short-cut carbon fiber: Toray Industries, Inc., 250 μm in length; Graphite powder: Qingdao Carbon, particle size 25μm; MoS2: Guoyao Reagent, purity ≥99.5%; PEEK micro powder: Victrex, particle size ≤10μm.

[0086] Nano-SiO2 functionalization treatment

[0087] 5g of SiO2 was dispersed in 100mL of ethanol / water (2:1) mixture and stirred at 300rpm for 20 minutes; Add 0.15g KH-792 (3% by weight) and stir for 1 hour; Adjust the pH to 4.8 with dilute acetic acid and continue the reaction for 30 minutes; Centrifuge (6000 rpm, 10 minutes), wash 3 times with ethanol; Vacuum dry at 75°C for 4 hours.

[0088] carbon fiber treatment

[0089] 10g of carbon fiber was placed in a mixture of sulfuric acid and hydrogen peroxide (volume ratio 3:1) for 30 minutes to oxidize. After washing until neutral, add 0.25g of KH-560 coupling agent (2.5% by weight) and stir at 80℃ for 1 hour; Filter by suction, wash three times with ethanol, and dry at 70°C for 5 hours.

[0090] Graphite powder treatment

[0091] The ball milling time was 2 hours, and the particle size distribution was controlled at 9μm±1.5μm.

[0092] PEEK micro powder preparation

[0093] Spray drying: inlet temperature 135℃, outlet temperature 82℃, particle size distribution 10μm±2μm.

[0094] Mixing and Dispersion

[0095] PTFE 100g, SiO2 3g, carbon fiber 10g, graphite powder 5g, MoS2 1g, PEEK 2g; Add 200mL of deionized water and stir at 400rpm for 10 minutes; Ultrasound for 15 minutes (power 450W).

[0096] Spray drying and dry mixing

[0097] Spray drying: inlet 135℃, outlet 82℃, moisture content ≤0.9%; Dry mixing: 3000 rpm, 6 minutes.

[0098] Forming and sintering

[0099] Molding pressure 55MPa; Sintering: Hold at 310℃ for 0.5 hours, then hold at 370℃ for 3 hours; Nitrogen flow rate: 0.85 L / min.

[0100] Surface treatment

[0101] Micro-blasting: 0.4MPa, 2 minutes; Laser microtexturing: 0.85 J / cm², scanning speed 5 mm / s.

[0102] Comparative Example 1

[0103] Preparation of an unmodified PTFE sealing ring

[0104] Raw material preparation

[0105] Fine polytetrafluoroethylene (PTFE) powder, with a particle size of approximately 30 μm; Unmodified nano-silica powder (average particle size 30nm). Short-cut carbon fibers (150 μm in length and 8 μm in diameter) that have not been treated with any coupling agent; Polyetheretherketone (PEEK) micro powder is obtained by direct mechanical pulverization without spray drying, and has a particle size distribution of 20~50μm.

[0106] Hybrid process

[0107] 100 parts of PTFE powder, 10 parts of unmodified nano-silica, 5 parts of unmodified chopped carbon fiber, and 8 parts of PEEK micro powder obtained by mechanical pulverization were added to a high-speed mixer and stirred at 500 rpm for 15 min. No ultrasonic dispersion was performed; initial homogenization was achieved solely through mechanical stirring.

[0108] Molding process

[0109] The mixture is poured directly into the mold and cold-pressed under 10MPa pressure to form a ring-shaped blank with a diameter of 60mm and a thickness of 5mm.

[0110] Sintering process

[0111] The annular blank was placed in a conventional electric furnace, heated to 360°C, held at that temperature for 2 hours, and then naturally cooled to room temperature to obtain the polytetrafluoroethylene sealing ring of Comparative Example 1.

[0112] Surface treatment

[0113] The surface of the resulting sealing ring was not subjected to any microstructural treatment, maintaining a traditional flat and smooth surface.

[0114] Comparative Example 2

[0115] Preparation of a pure PTFE sealing ring without composite fillers

[0116] Raw material preparation

[0117] Fine polytetrafluoroethylene (PTFE) powder, with a particle size of approximately 25 μm.

[0118] Hybrid process

[0119] Pure PTFE powder is used directly, without adding any inorganic nanofillers, carbon fibers or PEEK micro powder, and without any ultrasonic dispersion or surface modification.

[0120] Molding process

[0121] 100 parts of PTFE powder were directly loaded into a metal mold and cold-pressed under a pressure of 12 MPa to obtain a ring-shaped blank (outer diameter 60 mm, inner diameter 40 mm, thickness 5 mm).

[0122] Sintering process

[0123] The ring-shaped blank is placed in a conventional electric furnace, and the heating rate is controlled at 3℃ / min until it reaches 350℃. It is then held at that temperature for 1 hour and allowed to cool naturally to obtain a pure PTFE sealing ring.

[0124] Surface treatment

[0125] The surface of the sealing ring is left untreated, retaining its natural sintered surface.

[0126] To verify the performance advantages of the high wear-resistant polytetrafluoroethylene sealing ring of the present invention, friction and wear performance comparison experiments were conducted using Examples 1–4 and Comparative Examples 1–2.

[0127] Experimental steps

[0128] (1) Sample preparation: Seal ring samples were prepared according to the formulation and process steps of Examples 1–4 and Comparative Examples 1–2 respectively. The specifications were 60 mm outer diameter, 40 mm inner diameter and 5 mm thickness. Five samples were prepared for each group for parallel testing.

[0129] (2) Surface characterization: The morphology of the friction surface was observed by scanning electron microscopy (SEM), the hardness was measured by microhardness tester (Shore D), and the tensile strength and elongation at break were measured according to ASTM D638 standard.

[0130] (3) Friction and wear test: Dry friction test was conducted on an MMW-1 type pin-disc friction and wear testing machine. The grinding part was a polished and quenched bearing steel disc (AISI52100) with a surface roughness Ra=0.1μm. The test conditions were: load 100N, sliding speed 0.2m / s, time 2 hours, and total sliding distance 1440m. The environmental conditions were room temperature (23±2℃) and relative humidity 50±5%. The friction coefficient was continuously recorded during the test, and the mass loss of the sample was measured after the test.

[0131] (4) Wear rate calculation: Based on the composite material density ρ = 2.15 g / cm³ (i.e. 2.15 × 1 Convert using ³g / mm³.

[0132] Volume loss ΔV = Δm / ρ; Volume wear rate K = ΔV / (F×L), where F is the load (N) and L is the sliding distance (m).

[0133] Five samples were taken from each group, and the results are expressed as mean ± standard deviation.

[0134] Experimental data are shown in Table 1

[0135] The experimental data show that: The coefficients of friction of Examples 1–4 were all significantly lower than those of the comparative examples, with Example 3 having the lowest coefficient of friction at 0.100, which was 50% lower than that of pure PTFE (0.200).

[0136] The volumetric wear rate of all embodiments was 2.00 × 10⁻⁶. -6 ~2.50×10 -6 mm³ / (N·m), significantly lower than that of unmodified filler composite PTFE (5.00×10⁻⁶ mm³ / (N·m)). -6 ) and pure PTFE (6.20×10 -6 This improves wear resistance by approximately 60% to 68%.

[0137] The mass loss of the example was between 0.619 and 0.774 mg, while the mass loss of the pure PTFE sample reached 1.920 mg, indicating that the wear resistance life of the sealing ring of the example was significantly extended.

[0138] In terms of mechanical properties, the Shore D of the embodiments is superior to that of the comparative examples in terms of hardness and tensile strength. For example, the hardness of Example 3 is 64 and the tensile strength is 32 MPa, which are both improved compared to pure PTFE (hardness 50 and strength 20 MPa).

[0139] In summary, using nano-Si Surface functionalization, surface coupling modification of chopped carbon fibers, ball milling of graphite powder, spray drying of PEEK micropowder to control particle size, and wet dispersion combined with ultrasonication, segmented heating sintering, and surface microstructuring treatment, among other technical measures, effectively improve the filler dispersibility and interfacial bonding, thereby significantly reducing the coefficient of friction and wear rate, while simultaneously increasing hardness and strength. The sealing ring of this invention exhibits a longer service life and superior overall performance under high pressure, high speed, and high temperature conditions.

[0140] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high wear resistant polytetrafluoroethylene seal ring characterized by, According to mass parts, it is composed of the following components: Polytetrafluoroethylene resin (PTFE): 100 parts; Nano-silicon dioxide (SiO2): 3 parts; Graphite powder: 5 parts; Short carbon fiber: 10 parts; Molybdenum disulfide (MoS2) solid lubricant: 1 part; Polyether ether ketone (PEEK) micro powder: 2 parts.

2. The high wear resistant polytetrafluoroethylene seal ring according to claim 1, wherein, Nanosilicon The surface functionalization treatment includes the following steps: Disperse nano-SiO2 in an ethanol-water mixed solution (volume ratio 1:1) using a mechanical stirrer at 300 rpm for 30 minutes; Add 3-aminopropyltriethoxysilane (APTES) 3% mass parts to the dispersion and stir for 1.5 hours; Adjust the pH of the solution to 4.5 with dilute acetic acid; Centrifuge for 10 minutes at 5000 rpm, and wash the precipitate with ethanol 3 times; Dry the functionalized nano-SiO2 powder in an oven at 70°C for 4 hours.

3. The high wear resistant polytetrafluoroethylene seal ring according to claim 1, wherein, The short carbon fiber surface coupling agent treatment operation includes: Soak the short carbon fiber in an ethanol solution and add APTES coupling agent 2% mass parts; Stir for 1.5 hours in an 85°C oil bath; After the reaction, filter and wash with ethanol 3 times; Dry the treated short carbon fiber in an oven at 70°C for 4 hours.

4. The high wear resistant polytetrafluoroethylene seal ring of claim 1, wherein, The graphite powder is ball milled before being added to the mixture, with a ball milling time of 2 hours and a particle size distribution controlled at 10μm±2μm.

5. The high wear resistant polytetrafluoroethylene seal ring of claim 1, wherein, The PEEK micro powder is obtained by spray drying at a drying temperature of 140°C, with a particle size distribution controlled at 10μm±2μm.

6. The high wear resistant polytetrafluoroethylene seal ring of claim 1, wherein, Each filler is added to the PTFE in the following order: functionalized nano-SiO2 first, then short carbon fiber, followed by graphite powder, MoS2 solid lubricant, and PEEK micro powder.

7. A method of producing a high wear resistant polytetrafluoroethylene seal, characterized by, It includes the following steps: S1. Mix PTFE resin with the treated nano-SiO2, carbon fiber, graphite powder, MoS2 solid lubricant, and PEEK micro powder according to the proportions described in claims 2-6; S2. Add the mixture to deionized water, stir at 400 rpm for 10 minutes using a mechanical stirrer, and then use an ultrasonic processor for 10 minutes to ensure that each component is well dispersed, maintaining a temperature of 30-35°C; S3. Spray dry the wet dispersion, with an inlet temperature of 140°C and an outlet temperature of 85°C, to obtain a dry powder with a water content of ≤1%; S4. Dry mix the dry powder for 5 minutes with high shear to ensure uniform distribution of the fillers; S5. Press or extrude the dry mixed material obtained in S4 into a seal ring blank; S6. Perform staged temperature sintering under nitrogen protection, with a pre-sintering temperature of 310°C for 0.5 hours and a main sintering temperature of 370°C for 3 hours, and control the nitrogen flow during sintering at 0.8L / min to prevent oxidation; S7. Perform microstructure surface treatment on the sintered seal ring: Micro-blasting at a pressure of 0.4MPa for 2 minutes; Laser micro-texturing at a laser energy density of 0.8J / cm² and a scanning speed of 5mm / s.

8. The method of claim 7, wherein the high wear resistant polytetrafluoroethylene seal ring is prepared by the steps of: The combination of wet dispersion and ultrasonic treatment ensures that the nano-SiO2 powder is broken up and the short carbon fiber is evenly distributed. ​ 9. The method of claim 7, wherein the high wear resistant polytetrafluoroethylene seal ring is prepared by the steps of: The pressing pressure for the pressed tablet of the dry mixture is 50MPa, and the extrusion speed is 10mm / s. ​ 10. The method of claim 7, wherein the high wear resistant polytetrafluoroethylene seal ring is prepared by the steps of: The microstructure surface treatment only uses a combination of micro-blasting and laser micro-texturing. ​

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