A weather strip rubber wear-resistant material and a preparation method thereof, a weather strip and a preparation method thereof, and a vehicle

Abstract

The application discloses a sealing strip rubber wear-resistant material, which comprises the following components in parts by mass: EPDM: 100 parts; polyethylene: 120-400 parts; reinforcing agent: 0-35 parts; and operating oil: 3-25 parts. The sealing strip is prepared after co-extrusion of the EPDM base material and vulcanization and setting, and the sealing strip is applied to a carrier. The material has the advantages of good wear resistance, excellent weather resistance, small odor, firm joint and the like, and is suitable for production of sliding materials in vehicle window sealing strips of various vehicle types.

Description

Technical Field

[0001] This invention relates to the field of preparation technology of rubber wear-resistant materials for sealing strips, specifically to the field of preparation technology of ultra-high hardness EPDM rubber wear-resistant materials. Background Technology

[0002] Automotive window guide channel sealing strips are crucial functional components in automobiles, serving both sealing and guiding functions for the window glass. As automotive windows are frequently moved, they directly rub against the sealing strip during raising and lowering, requiring the strip to possess excellent wear resistance and low frictional resistance. The lower the frictional resistance of the sealing strip during the window's raising and lowering motion, the smoother the glass movement and the lower the coefficient of friction. The repeated raising and lowering of the window glass causes wear on the sealing strip, making its wear resistance a prerequisite for ensuring the long-term effective operation of the window glass.

[0003] The base materials for automotive glass guide channel sealing strips include ethylene propylene diene monomer (EPDM), thermoplastic elastomers, and polyvinyl chloride (PVC). EPDM boasts excellent overall performance, exhibiting superior aging resistance, UV resistance, high and low temperature resistance, and outstanding acid and alkali resistance. It also demonstrates strong environmental adaptability, excellent elasticity, and resistance to permanent deformation, making it a commonly chosen base material for rubber automotive glass guide channel sealing strips. Currently, the glass friction layer of rubber automotive glass guide channel sealing strips is processed using three methods: electrostatic flocking, spraying, and composite with polyethylene (PE) strips.

[0004] Electrostatic flocking involves applying an adhesive layer to a pre-treated rubber surface (e.g., plasma treatment). The adhesive-coated rubber sealing strip passes through an electrostatic flocking box, where charged fibers are vertically implanted into the adhesive layer at a certain speed along the direction of the electrostatic field, forming a layer of upright fibers on the surface of the rubber sealing strip. The flocked rubber sealing strip is then heated in an oven, where the adhesive cures, keeping the fibers on the surface. The flocking process is complex, requiring specialized equipment such as plasma generators, adhesive coating devices, electrostatic flocking boxes, and hot air curing chambers on the production line. A single production line is 20-35 meters longer than a conventional one. Furthermore, the fibers can easily fly out of the electrostatic flocking box, and the volatilization of VOCs from the adhesive can severely impact the production environment. Inhalation of these VOCs can harm workers' health and affect the final odor test rating of the sealing strip. Although dedicated flocking production processes have been developed, they are typically performed through extrusion molding, requiring specialized film-tearing and hot air curing equipment, and can only be done online (i.e., the flock tape is applied while the sealing strip is being extruded). The flocking tape used in applying the sealant often suffers from defects such as insufficient adhesion and poor abrasion resistance. During the extrusion production of the sealing strip, issues like misalignment and distortion during application can easily occur, leading to a high rework rate. Disadvantages include the fact that the flocking tape can only be applied to the bottom edge, not the lip edge. Applying it to both the bottom and lip edges requires complex and multi-step processes. Furthermore, flocking tape is generally not heat-resistant (because the adhesive is heat-sensitive, the tape easily detaches from the strip at high temperatures), and its sealing performance is poor, potentially causing abnormal noises when the window is raised or lowered. Additionally, regardless of whether flocking or applying the tape is used, the direct contact between the window glass and the flock layer makes it prone to shedding of the flock layer, severely affecting the cleanliness and aesthetics of the glass, and directly impacting the noise reduction effect of the flocking.

[0005] The application of spray coating technology to prepare wear-resistant coatings for rubber sealing strips is a new technology from the early 21st century. Wear-resistant coatings are smooth and aesthetically pleasing, with a low coefficient of friction, and have been well-received by users since their introduction. There are generally two methods for spraying wear-resistant coatings on sealing strips: traditional offline manual spraying and online automatic spraying, increasingly adopted by manufacturers. Offline spraying involves more steps and is more susceptible to human error, making it difficult to guarantee product quality stability. Compared to offline manual spraying, online automatic spraying produces a more uniform film thickness, a denser film, better adhesion, a more natural and aesthetically pleasing gloss, and more stable quality. It also results in less waste of spraying materials and labor costs, lower costs, and more consistent quality. Currently, the industry's production process for rubber sealing strips with sprayed wear-resistant layers is as follows: rubber mixing → microwave vulcanization → hot air vulcanization → water cooling → plasma surface treatment → online spraying → high-temperature curing → molding to length → surface treatment of corner areas → corner molding → corner area spraying → subsequent processing → packaging and warehousing. The mature online spraying process involves treating the product surface with corona or plasma after vulcanization, followed by high-temperature curing after spraying. However, this requires surface treatment equipment and a hot air curing oven on the extrusion production line. Furthermore, EPDM rubber is a non-polar material, making it difficult to directly bond with the sprayed material. Therefore, the industry generally requires applying a primer as a coupling agent before spraying the wear-resistant layer to ensure strong adhesion between the coating and the substrate. Overall, the spraying process is complex, and the coating is highly susceptible to cracking after exposure to UV rays, high temperatures, and organic solvents (such as gasoline), affecting the appearance of the sealing strip and the vehicle's overall aesthetics. This can lead to increased friction resistance, noise during glass sliding, scratches on the glass surface, and damage to the sealing strip itself. Moreover, current primers are mostly solvent-based, which has adverse effects on the environment and operators, and also affects the final VOCs content of the sealing strip.

[0006] Due to its excellent surface wear resistance, lubricity, and environmental friendliness, polyethylene (PE) offers significant advantages over surface flocking, patching, and coating techniques for sealing strips, leading to its increasingly widespread application in glass guide channel rubber sealing strips. Currently, a rubber-plastic composite process is typically employed, attaching a layer of modified wear-resistant and high-temperature-resistant PE material to the bottom of the sliding surface of the U-shaped glass guide channel sealing strip. This layer replaces the previous patched strip as a wear-resistant layer, improving the service life and performance of the automotive glass guide channel sealing strip. The production process involves extruding EPDM through an extruder and then laminating it with the PE strip within a die (hereinafter referred to as "die"). This material has relatively good wear resistance, improving the production environment of sealing strip products. However, at present, all of these products are imported, with high unit prices, which directly affect the final selling price of the sealing strips. Furthermore, the following technical problems exist: 1. Polyethylene requires a special mold and plastic extruder for extrusion, and must be bonded to the sealing strip substrate using an adhesive device. Any problem in any process results in defective products, leading to a low tolerance for error. 2. Due to differences in heating time and temperature, polyethylene and EPDM rubber often exhibit significant color differences after extrusion. Meanwhile, due to the characteristics of polyethylene material and the numerous processes involved, the surface of the extruded polyethylene strip has many irregular bumps, indentations, or scratches, affecting the product's aesthetics. This means that sealing strips produced by this process can only be used in generally unseen areas such as inside guide channels, leaving them exposed and affecting the overall vehicle appearance. 3. Because this type of polyethylene material has wear-resistant and high-temperature resistant properties, the temperature of the extruder head needs to be adjusted to above 200℃ during production to achieve smooth extrusion. However, since the PE extruder head and the EPDM extruder head are close together, the heat conduction effect will transfer the high temperature to the EPDM extruder head (usually around 70℃), causing the EPDM extruder head to become stuck (i.e., under the influence of high temperature, the EPDM is prematurely vulcanized and shaped at the extruder head before or during extrusion) and become blocked, affecting the product's production efficiency.

[0007] This application uses EPDM material as the base material for wear-resistant materials, and combines it with polyethylene, carbon black and other auxiliary materials through high-temperature mixing and other processes to produce an ultra-high hardness sealing strip wear-resistant material, which is used to replace the traditional flocking, spraying and PE tape wear-resistant treatment technology of glass guide channel sealing strips. In particular, it overcomes the defects of traditional PE tape materials, such as high extrusion conditions, many surface indentations and bumps, and high unit price. It has the advantages of low VOC content, smooth surface, wear resistance and low cost. Summary of the Invention

[0008] The purpose of this invention is to provide an ultra-high hardness EPDM rubber wear-resistant material (hereinafter referred to as EPDM lubricant) and its preparation method, thereby solving the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A rubber wear-resistant material for sealing strips comprises the following materials in parts by weight: EPDM: 100 parts; polyethylene: 120-400 parts; reinforcing agent: 0-35 parts; processing oil: 3-25 parts.

[0011] Further, the material comprises the following parts by weight: EPDM: 100 parts; polyethylene: 200-350 parts; reinforcing agent: 5-25 parts; processing oil: 5-15 parts.

[0012] Furthermore, the polyethylene is ultra-high molecular weight polyethylene.

[0013] Furthermore, the reinforcing agent is selected from one or more of carbon black, silica, graphene, carbon fiber, carbon nanotubes, MXene, and calcium powder; the processing oil is selected from one or more of paraffin oil, liquid polybutadiene, and dioctyl sebate.

[0014] Furthermore, the material also includes 0.1-10 parts of a vulcanizing agent.

[0015] Furthermore, the vulcanizing agent is selected from one or more of sulfur, phenolic resin, EG-3, DCP, DTDC, and DCBP.

[0016] The preparation method of the rubber wear-resistant material for sealing strips includes: mixing EPDM for 0.5-2 minutes, adding processing oil and mixing for 0.5-2 minutes, then adding polyethylene and reinforcing agents and mixing to 100-130 degrees Celsius, then discharging the rubber onto a rolling mill for cooling, filtering out strips, crushing and granulating to obtain the final product.

[0017] A sealing strip, wherein the sealing strip is provided with the aforementioned sealing strip rubber wear-resistant material.

[0018] Furthermore, the method for preparing the sealing strip includes: co-extruding the sealing strip substrate with the sealing strip rubber wear-resistant material, and then vulcanizing and shaping it to obtain the final product.

[0019] A vehicle equipped with the aforementioned sealing strip.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. The formulation of the slip material in this application is simple, requiring only EPDM, PE, reinforcing agent and processing oil, without the need to add traditional compatible materials such as PP and POE. The resulting slip material has a good composite effect with the EPDM substrate, a smooth and slippery surface, and excellent wear resistance. It overcomes the bias of the existing technology and can replace the imported PER wear-resistant material currently in use. As a domestic slip material, it breaks the technological advantage of foreign countries.

[0022] 2. When PER (modified wear-resistant and high-temperature resistant polyethylene) is used as a wear-resistant material, it is generally extruded together with EPDM substrate after melting (i.e., the material used in the sealing strip body). However, PER requires a dedicated plastic extruder, and the extrusion temperature needs to be raised to over 200℃ to meet the material's flowability requirements. This places high demands on the mold's heat insulation function, often requiring a dedicated heat insulation mechanism. Even so, the PER extruder die is still very prone to causing the EPDM substrate to become stuck in the extrusion die (i.e., the EPDM is directly vulcanized and blocked at the extrusion port due to the heat conducted from the PER mold at the die head) through heat conduction or heat radiation. In contrast, when using EPDM as a wear-resistant material, the mold temperature during extrusion only needs to be around 75℃, and the extrusion temperature of the EPDM substrate is similar, far below the temperature required for EPDM vulcanization (approximately 140-180℃). Therefore, no heat insulation mechanism is needed, the mold structure is simpler, and the stuck-die phenomenon during extrusion is eliminated.

[0023] 3. Glass groove sealing strips (also known as: car door and window frame sealing strips, glass guide groove sealing strips) require injection molding by combining 3-5 sealing strip parts with different cross-sectional shapes. The sealing strip material at the crossbeam position is generally composed of an aluminum skeleton / steel skeleton / plastic skeleton + various EPDM materials + sliding material / wear-resistant layer. The crossbeam section sealing strip is referred to as the A-section of the glass groove sealing strip, and the soft strips at the A-pillar and B-pillar positions are referred to as the C-section and B-section, respectively. After being punched, sections A, B, and C are injection molded together using EPDM or TPV through a butt-jointing mold. In practical production, when using EPDM as the rubber base material, if TPV is used as the corner material, there is a certain degree of poor joint performance (based on corner bonding strength). This is mainly due to the relatively poor compatibility between TPV and EPDM materials. If EPDM material is used as the corner material, since both the corner material and the sealing strip base material are EPDM, the compatibility is better, and naturally, the joint performance is also superior.

[0024] 4. In the overall vehicle sealing system, the sealing strips installed on the door and window frames have the most complex structure. This is because the corner sections must ensure a natural transition between the guide groove sealing strips with different extrusion cross-sections on both sides, while also meeting the functional and aesthetic requirements of the sealing strip in that area, and ensuring a secure connection. In actual production, companies typically divide the sealing strip into several segments according to the shape of the door. The corner joints require injection molding rubber to connect these segments into a single unit. Traditionally, corner joints are made using thermoplastic elastomers similar to TPV (ThinPrep Vase). However, due to the inherent low heat resistance of TPV material, it is generally maintained at a relatively low temperature in the injection molding machine to form a melt before being injected into the mold (with a sealing strip inserted at each end). After maintaining this temperature for a period of time, the joint can be removed to complete the corner connection. However, this type of corner joining technology has drawbacks such as poor high-temperature resistance (prone to cracking after prolonged use) and poor adhesion to the sealing strip substrate (because the substrate is EPDM material, TPV material cannot achieve a very good corner joining effect; this parameter can be reflected by the corner bonding force data). In the technical solution of this application, ultra-high hardness EPDM rubber wear-resistant material is used to composite and extrude with EPDM rubber sealing strips. The two sections of sealing strips are inserted into the two ends of the corner joining mold, and ordinary EPDM material is used as the corner joining material. During the corner joining process, the temperature of the corner joining mold is maintained at about 180-190℃, so that the EPDM immediately vulcanizes and sets as soon as it is injected into the part to be joined (i.e., the gap between the two sections of sealing strips). This corner joining technology has the advantages of strong corner joining, not easy to break / cracking after joining (both the sealing strip substrate and the corner substrate are EPDM, with good compatibility), good corner elasticity (EPDM elasticity is better than TPV material elasticity), and high temperature resistance of EPDM corner joining material. Attached Figure Description

[0025] Figure 1 This is a composite extrusion mold for traditional PER material and rubber compound, including: 11 - mold body; 12 - pin hole: used for fixed connection between the mold and the extruder head body; 13 - screw hole: used to fix the heating plate of the outer extrusion template (the heating plate is not shown; PER needs to be heat-melted in an environment above 200℃ before extrusion); 14 - PER extrusion hole: used for extruding PER material; 15 - rubber base material extrusion hole (for illustration only, not the actual structure); A heat insulation plate is also required to insulate the PER extrusion mold and the EPDM extrusion mold to avoid dead rubber in the EPDM extrusion die, which is not shown in the figure.

[0026] Figure 2This is a composite extrusion mold (i.e., three-component molding, or four-component molding if a skeleton is included) for EPDM lubricant and substrate (A) and substrate (B) rubber compounds. The components include: 21. Mold body; 22. Pin hole: used for fixing the mold to the extruder head body; 23. EPDM lubricant flow channel: through which the EPDM lubricant flows to the attachment location; 24. EPDM lubricant extrusion hole: used for extruding the EPDM lubricant; 25. EPDM substrate (A) rubber extrusion hole (illustrated only, not the actual structure); 26. EPDM substrate (B) rubber extrusion hole: used for extruding the substrate EPDM rubber; 27. Substrate EPDM rubber flow channel: through which the substrate EPDM rubber flows to the location covering the sealing strip skeleton (including metal and non-metal skeletons). The soft EPDM rubber compound refers to EPDM rubber compound with a Shore A hardness of less than 95 after vulcanization.

[0027] Figure 3 These are photos of PER abrasion-resistant material (red box ①) and EPDM abrasion-resistant material (blue box ②) after being compounded and extruded with a rubber substrate. It can be seen that the surface of the PER abrasion-resistant material has irregular bumps, while the surface of the EPDM abrasion-resistant material is smooth and has no irregular bumps.

[0028] Figure 4 These are photographs of the slip materials under a microscope, wherein: (a) the TPV slip material manufactured in Comparative Example 8 of this application; (b) the PE slip material manufactured in Comparative Example 5 of this application; and (c) the slip material manufactured in Example 12 of this application. Detailed Implementation

[0029] To make the technical means, distinguishing features, objectives and beneficial effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0030] Unless otherwise specified, all raw materials and reagents used in the embodiments of this invention are commercially available, and all quantities are by weight.

[0031] The means of transport refers to vehicles, ships, containers, aircraft, carrier rockets, railway freight cars, passenger cars, etc., that is, the means of transport in transportation. In this application, the means of transport shall have windows, the window frames shall be provided with sealing strips, the sealing strips shall have the sliding material described in this application, and the frame of the window lifting assembly shall be directly pressed and rubbed against the aforementioned sliding material.

[0032] Before the test, the samples were placed in a standard test chamber environment [temperature: 23±2℃, humidity: 50%±5%] for 16 hours for conditioning. The appearance of the friction layer of the samples was observed to ensure that it met the requirements: the flocked surface of the flocked rubber glass guide channel sealing strip was uniformly flocked, clean, and free of adhesive residue or other stains, with no lint shedding or exposed substrate; the sprayed surface of the sprayed rubber glass guide channel sealing strip had uniform color, a smooth feel, no obvious flakes, scratches, or coating peeling; the appearance of the PE and EPDM slip materials was free of impurities, bubbles, cracks, and scratches, and the composite was tight, straight, and smooth.

[0033] Material thickness: Take 2-5mm thick slices from the same location on different finished products, ensuring parallel cutting and preventing sample distortion during the cutting process. Place the sample flat on the microscope stage, adjust the microscope lenses to obtain a suitable sample image (minimum magnification 50x), aim the camera at the image, and use imaging software to display the sample image on the computer screen. The system should be set to a full-screen magnification range of 600x to 1400x. Position the image at the desired measurement location and optimize the focus. Finally, use the software to measure the coating on the acquired image.

[0034] The friction coefficient was measured using a friction coefficient meter according to the relevant national standard GB / T4074.3-2008. The friction coefficient is proportional to the friction force, and the friction resistance of the rubber glass guide groove sealing strip is reflected by testing the friction coefficient.

[0035] Abrasion test specimen requirements: Cut a 200mm long specimen from the sealing strip.

[0036] Test method: a) Dry grinding: After placing 3 samples in an environment with standard temperature and humidity requirements for 16 hours, a wear test was conducted with a load of 1 kg and a wear resistance of 15,000 cycles.

[0037] B) Wet abrasion: After placing 3 samples in a standard temperature and humidity environment for 16 hours, immerse the samples in clean water at (23±2)℃ for 1 hour and take them out. Perform abrasion test in a wet state and keep them wet. Add about 2 mL of clean water to the sample every 2000 abrasions. The load is 1 kg and the abrasion resistance is 12000 cycles.

[0038] c) Mud-water grinding: After placing three samples in a standard temperature and humidity environment for 16 hours, mud-water is dripped onto their surfaces to ensure the sample surfaces are completely wet during the abrasion test. The samples are kept moist, with approximately 2 mL of mud-water added every 500 abrasion cycles. The load is 1 kg, and the abrasion resistance is 3000 cycles. [Mud-water standard: Sand to water ratio 1:3; coarse sand (185-200μm) to fine sand (27-31μm) ratio 1:3; sand material requirements: silicon dioxide ≥97%, ferric oxide + aluminum oxide + magnesium oxide ≤3%.]

[0039] After the above wear test is completed, observe the surface of the lubricant. If there is no obvious detachment of the lubricant, no obvious exposure of the substrate, and the wear rating of the lubricant is ≥4, the test is passed and indicated by “√”. If there is obvious detachment of the lubricant, obvious exposure of the substrate, or the wear rating of the lubricant is below 4, the test is failed and indicated by “×”.

[0040] Among them, the limit dry grinding cycle, the limit wet grinding cycle, and the limit mud and water grinding cycle refer to the number of friction cycles (in units of 100) when the material is obviously detached, the substrate is obviously exposed, or the material wear rating is below level 4 (excluding level 4) under the premise of a load of 1kg.

[0041] Corner bond strength: Cut a specimen containing a corner or joint, with the corner portion positioned in the center of the specimen. Place the specimen containing the corner or joint on a tensile testing machine, with the clamps positioned 20 mm outside the corner bond line (or 50 mm outside the joint seam). Apply tension at a speed of 200 m / min and measure the maximum force at break. Take the minimum value of all test data as the result.

[0042] Odor Test: Place the sample in a test container without adding water. Seal the container tightly and place it in a preheated electric thermostatic drying oven to a temperature of (80±2)℃ for (2h±10min). Then remove the test container from the oven and allow it to cool to (60±5)℃ before evaluation. During evaluation, bring your nose close to the edge of the open bottle, with the edge between your nose and lips. The evaluator's nose should be approximately 2-3cm from the bottle opening. The bottle cap should not be open for more than 10 seconds, and the evaluator should inhale normally. Odor Level Determination: Level 1: No odor; Level 2: Slight odor, but no interfering odor; Level 3: Obvious odor, but no interfering odor; Level 4: Interfering odor; Level 5: Strong interfering odor; Level 6: Unbearable odor. Data should be accurate to one decimal place. Five evaluators should jointly evaluate and write individual evaluation comments.

[0043] VOCs content test: Test temperature conditions: Sampling bag temperature 40±2℃, holding time 4.5h±5min. Sampling tube collection conditions—volatile organic compounds TENAX tube, sampling rate 0.2L / min, sampling time 15min, sampling volume 3L; aldehyde and ketone adsorption tube DNPH tube, sampling rate 0.8L / min, sampling time 30min, sampling volume 24L.

[0044] Low temperature resistance: Cut a 200-mm-long specimen from the non-joint part of the product, and ensure that the surface has no abnormalities such as holes, dirt, cracks, etc. Place the specimen and an inert material mandrel with a diameter of 50 mm in a low-temperature chamber at (-40±2)°C for 8 h, and then take out the specimen and the mandrel with appropriate protective equipment. Bend the specimen with its working surface facing outwards along the mandrel by 180° within 5 s, and visually inspect whether there are cracks or peeling on the surface of the specimen and the surface treatment. If there are cracks or peeling, record it as "×"; if there are no cracks or peeling, record it as "√".

[0045] Heat resistance: According to Method B in ISO188, keep it at (90±3)°C for 24 h, bend the specimen into a semi-circular arc with a radius of (25±0.5) mm, and conduct an appearance inspection.

[0046] Heating length change rate: Cut 200-mm-long specimens from the product according to different cross-sections. Accurately measure the length of the specimen with a vernier caliper (accurate to 0.1 mm), place it horizontally in a test chamber at (80±2)°C for 48 h, then take out the specimen, let it stand at room temperature for 24 h, and then accurately measure the length of the specimen again, and calculate the length change rate. Take the arithmetic mean as the test result.

[0047] Artificial weathering aging: Cut specimens with a surface width of 20 mm and a length of 200 mm from the finished product. Install the specimens on the specimen rack in a free state, place the specimens evenly. If two or more specimens are placed on the same plate, the distance between the specimens shall be not less than 40 mm, and the specimens shall be avoided from being affected by external stresses. Ensure that the exposed surface of the specimen faces the light source directly, and the working area (appearance surface) area of the specimen is completely exposed within the effective light source range, and adjust the test environment of the xenon chamber;

[0048] The test conditions for interior trim parts (such as glass wool grooves, door strips, door frame strips, side window seals, luggage compartment strips, rear door frame seals, engine compartment strips, inner water cuts, etc., which are interior seals in the vehicle compartment) are: blackboard temperature 83±2°C, relative humidity (20±10)%, no water spray, radiation intensity 550W / m 2 , and the test time is 300 h;

[0049] After the test is completed, take out the specimens and conduct an appearance inspection with a 7-fold magnifying glass. Visually inspect the exposed surface of the specimens, and compare it with the retained specimens that have not undergone the exposure test to evaluate the change in surface color and other appearance changes. There should be no defects such as cracks, powdering, cracking, softening, hardening, sticking, embrittlement, spots, delamination, deformation, stains, exudates, mildew, blooming, etc. on the surface of the specimens. The color change grade is evaluated according to the gray card evaluation standard of GB / T 250-2008, and slight color change is allowed. The judgment grade ≥4 is considered qualified. If it is unqualified, record it as "×"; if it is qualified, record it as "√".

[0050] Ozone aging resistance: Cut a sample with a length of (150±2) mm from the finished product. Fix the sample to a glass plate with enameled wire or equivalent material. The ozone concentration is (200±20)×10 -8 The test temperature is (40±2)℃. The fixed sample is placed in the ozone test chamber, and the test conditions are kept stable for 72 hours. After the test, the sample is removed and placed in an environment of (23±2)℃ for 2 hours. Then, the sample surface is inspected with a 7x magnifying glass for cracks or fractures. The sample should not be touched during the inspection. The absence of cracks or the presence of crazing are considered the test result. Crazing is marked as "×", and no cracks are marked as "√".

[0051] Sliding force of glass sealing surface: Samples of (200±20) mm in length were cut from the same position on different finished products. The samples were symmetrically assembled on the fixture, and the glass plate was mounted on the testing machine fixture. During installation, the glass plate should be aligned with the center line of the fixture with the sample. The water-cutting test should ensure that the lip and glass compression meet the drawing requirements. A suitable glass plate insertion depth and speed were set; the insertion depth should allow the glass plate to pass through the lower end of the sample but not touch the bottom of the fixture; the insertion speed was set to 100 mm / min. The testing machine was started, and the glass was brought into contact with the sample and inserted into the sample at a speed of 10 mm / min for approximately 20 mm, while ensuring no abnormal deformation of the sample occurred. After stabilization, the glass plate was inserted again at a speed of 100 mm / min for approximately 200 mm, and then pulled out of the sample in the opposite direction. Each group of samples underwent 5 cycles of rising and falling, and the maximum force value during each insertion and withdrawal process was recorded. The arithmetic mean was calculated, and a sliding force curve was plotted. The maximum value among the arithmetic mean values ​​of the three pairs of samples was taken as the test result.

[0052] Solvent resistance: The minimum friction stroke is 80 mm, the downward pressure is 4.3 N, each cycle is 1 second, and a total of 10 cycles are performed (each cycle includes back and forth motion). The sample surface coating is tested after being coated or wetted with the following reagents respectively: a) protective wax, b) automotive chemical shampoo, c) chemical paint cleaner, d) household chemical car window ammonia cleaner, e) chemical chromium-containing cleaner and polishing agent.

[0053] Chemical and abrasion resistance: The minimum friction stroke is 80 mm, each cycle lasts 1 second (one cycle includes back-and-forth motion), and the downward pressure is 9 N. The surface coating must not be worn off in any of the following tests: a) Dry fabric, ≥100 cycles; b) Wet fabric (wetted with deionized water), requiring 50 cycles of dry testing before wetting, ≥100 cycles; c) Wet fabric (wetted with clean antifreeze solution), (2-propanol):water = 1:2, requiring 50 cycles of dry testing before wetting, ≥100 cycles; d) Wet fabric (wetted with windshield cleaning solution), (methanol):water = 2:3, requiring 50 cycles of dry testing before wetting, ≥100 cycles. If there is no wear and no scratches, mark with "√"; if any part is worn or scratched, mark with "×".

[0054] Cross-cut test: a) Place the sample on a sufficiently hard plate, hold the cross-cutting tool handle, and keep the multi-blade cutter perpendicular to the sample plane; b) Cut the sample with uniform pressure, a steady and non-vibrating motion, and a cutting speed of 20-50 mm / s. The cuts should penetrate the coating. The spacing between cuts in each direction should be 1 mm. Rotate the sample 90 degrees and repeat the above operation to form a grid pattern; c) Perform the test at three different locations on the sample coating surface. Use a soft brush to gently brush the grid pattern diagonally forward and backward five times each. d) Cut a piece of adhesive tape approximately 75mm long and place it on the cut sample; d) Press the adhesive tape flat above the grid area with your fingers, ensuring the tape extends at least 20mm beyond the grid; e) Within 5 minutes of applying the tape, hold the suspended end at approximately a 60° angle and gently peel it off within 0.5–1 second; f) Carefully inspect the cut area of ​​the coating under good lighting (or observe using a 2–3x magnifying glass) and grade the coating peeling condition according to the standard. If the grading result is Grade 1, mark it as “√”; if the grading result is ≥ Grade 2, mark it as “×”.

[0055] EPDM slip base formulation: EPDM: 100 parts; ultra-high molecular weight polyethylene: 120-400 parts; reinforcing agent: 0-35 parts; processing oil: 3-25 parts.

[0056] The ultra-high molecular weight polyethylene refers to linear polyethylene with a molecular weight of over 1 million.

[0057] It should be noted that in the embodiments, if only the word "polyethylene" appears, it indicates that ordinary conventional polyethylene is used, especially linear polyethylene with a molecular weight of less than 1 million.

[0058] The reinforcing agent is selected from one or more of carbon black, silica, graphene, carbon fiber, carbon nanotubes, MXene, and calcium powder; the processing oil is selected from one or more of paraffin oil, liquid polybutadiene, and dioctyl sebate.

[0059] Depending on actual production needs, it may be necessary to add a vulcanizing agent: 0.1-10 parts, or use it in conjunction with a vulcanization accelerator. The vulcanizing agent is selected from a series of conventional vulcanizing agents such as sulfur, phenolic resin, EG-3, DCP, DTDC, and DCBP. It can be used alone or in combination, or it can be used together with a series of conventional vulcanization accelerators such as DM, CZ, and DTDM.

[0060] EPDM gliding material mixing method: First, add EPDM and mix for 0.5-2 minutes, then add processing oil and mix for another 0.5-2 minutes. Next, add polyethylene material and reinforcing agent and mix to 100-130 degrees Celsius. Then add vulcanizing agent and mix until the temperature reaches 125-145 degrees Celsius. Discharge the rubber onto a two-roll mill for cooling. After sheeting, filter the rubber into strips using a rubber filter. After crushing and granulation, EPDM gliding material is obtained.

[0061] Preparation method of EPDM substrate (A) and (B) rubber compounds: Refer to the embodiment of CN112063058A. In a Banbury mixer, add 100 parts EPDM, 2 parts stearic acid, 5 parts nano-active zinc oxide, and 2 parts polyethylene glycol, and mix for 60 seconds with the top plug pressed. Then add 80 parts carbon black and 60 parts white oil and mix to 160°C to ensure the filler is fully combined and evenly dispersed. Then discharge the rubber. Cool to 135°C in a two-roll mill, add accelerators (5 parts ZBPD, 3 parts CLD-80, 2 parts TBZTD-70, and 1 part MBT-80) and mix for 2-3 minutes until the material is fully absorbed. Sheet the material and air-cool it on a cooling line for 10 minutes, then collect and let it stand for 8 hours. After the standing period, add the above rubber compound to the Banbury mixer and mix for 1 minute, then add 0.8 parts S and mix at 80°C for 3 minutes. Discharge the rubber. Sheet the material and cool it on a cooling line for 10 minutes. Collect the material, inspect for quality, and store it in the warehouse. The rubber was left in the warehouse for 24 hours, with the rubber material hanging on the truck and the temperature at 20-25 degrees Celsius and the humidity at less than or equal to 70%. The warehouse was ventilated once every hour.

[0062] The formulations of compounds (A) and (B) can be adjusted according to actual production conditions to achieve different hardness levels. Microporous foaming agents or foaming agents can also be added to the compounds to produce low-VOCs sealing strips or sponge rubber sealing strips. Alternatively, one compound can have a foaming agent added while the other does not, achieving a soft-hard composite extrusion effect.

[0063] Sealing strip preparation method: Refer to the embodiment in CN112063058A, placing different rubber compounds into different extruders, and then through a mold (refer to...). Figure 2Three rubber extruders are needed to extrude the base material (A), base material (B) and EPDM lubricant respectively. It can be determined whether to co-extrude with metal or plastic skeleton according to actual needs. The materials are then continuously vulcanized by high temperature vulcanization, microwave vulcanization and hot air vulcanization. After vulcanization and shaping, they are cut to a fixed length. If necessary, injection molding or joint vulcanization molding can be performed.

[0064] Preferably, high-temperature vulcanization is carried out in a 3-meter-long high-temperature chamber at a temperature of 370-380℃; microwave vulcanization is carried out in a 9-meter-long microwave chamber at a temperature of 230-240℃; and hot air vulcanization is carried out in a hot air chamber, which has three sections, each 9 meters long, at a temperature of 270-280℃. The extruded rubber compound passes sequentially through the high-temperature chamber, microwave chamber, and hot air chamber at a speed of 8-10 meters per minute. This continuous vulcanization ensures thorough reaction of various accelerators and vulcanizing agents. Finally, it is cooled in an 18-meter-long air-cooling chamber, resulting in a lower VOC content in the product.

[0065] As a preferred method, the cut sealing strips are hung and baked to dissipate odors. Specifically, the cut sealing strips are hung on the vehicle frame and baked in an oven at a temperature of 70-80℃ for 3.5-4.5 hours. The oven is ventilated every hour to ensure that the odors from the rubber strips are fully dissipated.

[0066] Sealing strip corner joining method: After heating the sealing strip corner joining mold to 180-190℃, insert the two sealing strip sections prepared using the above process into the sealing strip corner joining mold respectively. Inject rubber (EPDM or TPV) into the mold using a rubber injection molding machine, and maintain pressure for a period of time (pressure and time can be determined through limited tests based on existing technology in this field). This completes the corner joining of the sealing strip. Subsequent processes such as trimming and quality inspection can be added.

[0067] Comparative Example 1: Preparation of ordinary EPDM sealing strips. First, EPDM was added and mixed for 1 minute, then processing oil was added and mixed for another minute. Next, a reinforcing agent was added and mixed to 120°C. Then, a vulcanizing agent was added and mixed until the temperature reached 135°C. The mixture was discharged onto a two-roll mill for cooling. After sheeting, it was filtered through a filter to obtain strips. After crushing and granulation, an EPDM lubricating material comparison was obtained. The above lubricating material comparison was extruded separately from the EPDM base material and then laminated in a mold. Sealing strips were then manufactured using the aforementioned sealing strip preparation method.

[0068] Comparative Example 2: Preparation of electrostatic flocked EPDM sealing strip. EPDM substrate material was extruded using an extruder, followed by plasma treatment and electrostatic flocking. The flocking adhesive was FLOCKLOK 852F type acrylic adhesive from Lord International Trading (Shanghai) Co., Ltd., and the flock material was nylon with a specification of 0.6mm × 3.3dtex. The strip was then vulcanized and set.

[0069] Comparative Example 3: Preparation of online flocked EPDM sealing strip. Swiss flocked tape, with a flocked layer on one side and a smooth surface coated with heat-sensitive adhesive on the other. EPDM base material is extruded and then vulcanized. At the vulcanization chamber outlet, a flocking device is used to attach the flocked tape to the surface of the EPDM strip. Under certain pressure conditions, the residual heat of the vulcanized strip melts the heat-sensitive adhesive layer under the flocked tape, thus adhering the flocked tape to the surface of the EPDM strip.

[0070] Comparative Example 4: Preparation of wear-resistant coated EPDM sealing strips. EPDM substrate was extruded using an extruder, and the surface was plasma-treated before being sprayed with a Stahl water-based polyurethane coating. The coating thickness was 18–22 μm. The strip was then vulcanized and set.

[0071] Comparative Example 5: Preparation of PE Composite EPDM Sealing Strip. EPDM base material was extruded using an extruder and then co-extruded with a PE strip (from another extruder) in a die. The strip was then vulcanized and shaped to obtain the final product. The PE strip used modified wear-resistant and high-temperature resistant PE material produced by Guizhou Hexin Chemical Co., Ltd., with an extrusion thickness of 0.3 mm.

[0072] Comparative Example 6: 64 parts PP, 36 parts EPDM, 40 parts ultra-high molecular weight polyethylene, 10 parts POE, 2.6 parts carbon black, 4 parts phenolic resin, 0.6 parts antioxidant (1010), and 7.9 parts silicone oil. PP, EPDM, POE, carbon black, phenolic resin, and antioxidant were fed into the first hopper of a twin-screw extruder, while polyethylene was fed into a second hopper adjacent to the first hopper, with the second hopper closer to the extrusion end of the extruder. The mixture was then melt-extruded at 120°C and granulated to obtain the final product. EPDM-based rubber compound was extruded and then co-extruded with the above materials in a die, followed by vulcanization and setting to obtain the final product.

[0073] Comparative Example 7: 64 parts PP, 36 parts EPDM, 40 parts ultra-high molecular weight polyethylene, 10 parts POE, 2.6 parts carbon black, 4 parts phenolic resin, 0.6 parts antioxidant (1010), and 30 parts silicone oil. PP, EPDM, POE, carbon black, phenolic resin, and antioxidant were fed into the first hopper of a twin-screw extruder, while polyethylene was fed into a second hopper adjacent to the first hopper, with the second hopper closer to the extrusion end of the extruder. The mixture was then melt-extruded at 120°C and granulated to obtain the final product. EPDM-based rubber compound was extruded and then co-extruded with the above materials in a die, followed by vulcanization and setting to obtain the final product.

[0074] Comparative Example 8: 64 parts PP, 36 parts EPDM, 70 parts ultra-high molecular weight polyethylene, 10 parts POE, 2.6 parts carbon black, 4 parts phenolic resin, 0.6 parts antioxidant (1010), and 30 parts silicone oil. PP, EPDM, POE, carbon black, phenolic resin, and antioxidant were fed into the first hopper of a twin-screw extruder, while polyethylene was fed into a second hopper adjacent to the first hopper, with the second hopper closer to the extrusion end of the extruder. The mixture was then melt-extruded at 120°C and granulated. EPDM-based rubber compound was extruded and then co-extruded with the above materials in a die, followed by vulcanization and setting.

[0075] Example 1: EPDM: 100 parts, polyethylene: 120 parts, carbon black: 0 parts, paraffin oil: 3 parts.

[0076] Example 2: EPDM: 100 parts, polyethylene: 120 parts, carbon black: 10 parts, paraffin oil: 3 parts.

[0077] Example 3: EPDM: 100 parts, polyethylene: 200 parts, carbon black: 10 parts, paraffin oil: 5 parts.

[0078] Example 4: EPDM: 100 parts, polyethylene: 300 parts, carbon black: 10 parts, paraffin oil: 10 parts.

[0079] Example 5: EPDM: 100 parts, polyethylene: 400 parts, carbon black: 10 parts, paraffin oil: 10 parts.

[0080] Example 6: EPDM: 100 parts, polyethylene: 350 parts, carbon black: 25 parts, paraffin oil: 15 parts.

[0081] Example 7: EPDM: 100 parts, ultra-high molecular weight polyethylene: 120 parts, carbon black: 0 parts, paraffin oil: 3 parts.

[0082] Example 8: EPDM: 100 parts, ultra-high molecular weight polyethylene: 120 parts, carbon black: 10 parts, paraffin oil: 3 parts.

[0083] Example 9: EPDM: 100 parts, ultra-high molecular weight polyethylene: 200 parts, carbon black: 10 parts, paraffin oil: 5 parts.

[0084] Example 10: EPDM: 100 parts, ultra-high molecular weight polyethylene: 300 parts, carbon black: 10 parts, paraffin oil: 10 parts.

[0085] Example 11: EPDM: 100 parts, ultra-high molecular weight polyethylene: 400 parts, carbon black: 10 parts, paraffin oil: 10 parts.

[0086] Example 12: EPDM: 100 parts, ultra-high molecular weight polyethylene: 350 parts, carbon black: 25 parts, paraffin oil: 15 parts.

[0087] Example 13: EPDM: 100 parts, polyvinyl alcohol: 35 parts, carbon black: 25 parts, paraffin oil: 15 parts.

[0088] Example 14: EPDM: 100 parts, polyethylene wax: 35 parts, carbon black: 25 parts, paraffin oil: 15 parts.

[0089] Example 15: EPDM: 100 parts, ultra-high molecular weight polyethylene: 200 parts, carbon black: 10 parts, paraffin oil: 5 parts, sulfur: 1 part.

[0090] Example 16: EPDM: 100 parts, ultra-high molecular weight polyethylene: 300 parts, carbon black: 10 parts, paraffin oil: 10 parts, sulfur: 1 part.

[0091] Example 17: EPDM: 100 parts, ultra-high molecular weight polyethylene: 400 parts, carbon black: 10 parts, paraffin oil: 10 parts, sulfur: 1 part.

[0092] Example 18: EPDM: 100 parts, ultra-high molecular weight polyethylene: 350 parts, carbon black: 25 parts, paraffin oil: 15 parts, sulfur: 1 part.

[0093] Example 19: EPDM: 100 parts, ultra-high molecular weight polyethylene: 350 parts, carbon black: 25 parts, paraffin oil: 15 parts, sulfur: 3 parts.

[0094] Example 20: EPDM: 100 parts, ultra-high molecular weight polyethylene: 350 parts, polyvinyl alcohol: 35 parts, carbon black: 25 parts, paraffin oil: 15 parts.

[0095] Example 21: EPDM: 100 parts, ultra-high molecular weight polyethylene: 350 parts, polyvinyl alcohol: 35 parts, carbon black: 25 parts, paraffin oil: 15 parts, sulfur: 1 part.

[0096] Example 22: EPDM: 100 parts, ultra-high molecular weight polyethylene: 350 parts, phenolic resin: 35 parts, carbon black: 25 parts, paraffin oil: 15 parts, sulfur: 1 part.

[0097] Example 23: Ultra-high molecular weight polyethylene: 350 parts, polyvinyl alcohol: 35 parts, carbon black: 25 parts, paraffin oil: 15 parts.

[0098] Examples 1-22 refer to the preparation method of EPDM gliding material mixing, specifically: first, add EPDM and mix for 1 minute, then add paraffin oil and mix for another minute, then add polyethylene material and carbon black and mix to 120°C, then add vulcanizing agent and mix until the temperature reaches 125°C, discharge the rubber onto an open mill for cooling, and after sheeting, put it into a filter to filter out strips, crush and granulate to obtain EPDM gliding material. Simultaneously, the gliding material and EPDM substrate are co-extruded, vulcanized and shaped, and then some parameters are tested. When testing only the gliding material, the gliding material needs to be cut off separately and completely with a knife for testing; the rubber substrate is not included in the performance test, such as the heating length change rate. Example 23 was implemented according to Comparative Example 5, but this rubber compound could not be compounded with the EPDM substrate due to poor bonding strength, and could not pass the friction test; therefore, it will not be included in the comparison later. The test results of Examples 1-22 are recorded in the table below.

[0099]

[0100]

[0101] A comprehensive analysis of the test results of the above comparative examples shows that pure EPDM material is unable to withstand the friction of glass lifting and lowering, and therefore fails the performance test. The electrostatic flocking or online flocking methods have a high coefficient of friction and cannot pass the mud-water grinding test. Based on our production experience, this is mainly because during mud-water grinding, solid particles cut the flocked fibers during reciprocating friction, leading to a rapid decrease in the material's wear resistance. Looking at comparative examples 2, 3, 4, and 5, we can see that the wear resistance of the PE strip is significantly better than that of the three traditional methods mentioned above, with a lower coefficient of friction and easier glass lifting and lowering. Looking at comparative examples 6, 7, and 8, we can see that the coefficient of friction of these three comparative examples is higher than that of comparative example 5, and the number of dry abrasion cycles is less than that of example 5. We speculate that this is because the wear-resistant material made using this method essentially forms a TPV / TPE material with PP as the continuous phase and EPDM as the island phase. Although this increases the number of abrasion cycles to some extent, it is also relatively soft, increasing the sliding resistance of the glass and thus causing an increase in the coefficient of friction.

[0102] From the embodiments of this application, the difference between Examples 2-6 and Examples 7-12 lies in the different polyethylene materials used. From the data of the examples, we can clearly see that the performance of the examples using ultra-high molecular weight polyethylene is significantly better than that of the examples using ordinary molecular weight polyethylene. We speculate that this is because ultra-high molecular weight polyethylene has fewer branches and a longer main chain, which can reduce wear and provide better hardness in the friction test. Furthermore, we conducted performance tests on the hardness (unit: Shore A, degrees) of Comparative Examples 6-8 and Examples 7-12 according to GB / T531-2008 "Test Method for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber". The hardnesses of Comparative Examples 6-8 were 84, 82, and 87, respectively, while the hardnesses of Examples 7-12 were 91, 94, 95, 96, 97, and 98, respectively.

[0103] Further examination of Examples 13 and 14 shows that polyvinyl alcohol and polyethylene wax have almost no effect on the wear resistance of the material. The conclusions of Examples 19, 20, and 21 also support this view; the addition of polyvinyl alcohol and polyethylene wax may even worsen the wear resistance of the material. This is mainly because the addition of polyvinyl alcohol and polyethylene wax reduces the hardness of the product, thus affecting the wear resistance. Examples 15-19 further added sulfur to the extrusion of Examples 8-12 to assist in the crosslinking of EPDM. From the experimental data, we can see that the addition of sulfur has a certain positive effect on the wear resistance and friction coefficient of the material, but the improvement effect is not significant.

[0104]

[0105]

[0106] A comprehensive analysis of the test results of the above embodiments shows that, in terms of odor parameters, Comparative Example 1 has a relatively low odor, while Comparative Examples 2-4 generally have a stronger odor and higher VOC content. This is related to the use of flocking adhesive, heat-sensitive adhesive, and spraying materials in the material production process. Comparative Example 5 has better odor performance than the previous examples, but its overall odor level is still relatively high. We speculate that this may be related to the modified additives in the modified wear-resistant and high-temperature resistant PE material. The odor of Comparative Examples 6-8 has improved compared to Comparative Example 5, but the overall odor level is still poor. We speculate that this may be related to the addition of phenolic resin and other minor ingredients. Comparing Examples 1-6 and Examples 7-12, the overall odor level and VOC content are not significantly different, but are more pronounced compared to Comparative Examples 2-8. This is mainly because the material formulation of this application is simple and does not use easily volatile raw materials. The odor level and VOC content of Examples 13 and 14 have deteriorated significantly. This may be related to the fact that the added polyvinyl alcohol and polyethylene wax are prone to decomposition at high temperatures, producing alcohol gases. Compared with Examples 7-12, Examples 15-19 show an overall increase in odor level and VOC content, mainly because the addition of sulfur leads to an increase in product odor.

[0107] In terms of the heating length change rate, the heat resistance of the ultra-high molecular weight polyethylene used in Examples 7-12 was significantly improved compared with that of Examples 1-6, while the heat resistance of the vulcanized slip materials in Examples 15-19 was also superior.

[0108] The sliding force of the glass sealing surface is an important parameter used to measure how easily automotive glass can be raised and lowered within the sealing strip. Generally, the smaller this parameter, the easier it is for the automotive glass to be raised and lowered. Comparing the data from Examples 7-12 and 14-19 with those from other comparative examples or embodiments, we can clearly see that the sliding force of the glass sealing surface of the sliding material prepared in Examples 7-12 and 14-19 has a significant advantage. We speculate that this is largely due to its very smooth surface reducing the resistance during glass raising and lowering, thus allowing the glass to be raised and lowered easily.

[0109] In summary, considering the five parameters—low-temperature resistance, artificial climate aging, ozone aging, chemical and abrasion resistance, and cross-cut adhesion test—we can clearly see that Examples 7-12 and 15-22 generally outperform the other comparative examples and examples. This is closely related to the EPDM material in the EPDM lubricant. EPDM has good weather resistance and low-temperature resistance, allowing the lubricant to be used for extended periods in high-temperature, low-temperature, high-low temperature alternating, and other harsh environments. In contrast, the EPDM content in Comparative Examples 6-8 is low, making it difficult to achieve good weather resistance. While the PE in Comparative Example 5 exhibits good high-temperature performance, it is very prone to embrittlement at low temperatures. Friction and impact during glass lifting can easily cause PE particles on the surface to detach and tear, ultimately resulting in abnormal noise or difficulty in glass lifting, affecting the vehicle's use in low-temperature environments.

[0110] For a comparison of the surface quality of the slip material in Comparative Example 5 and Example 12, please refer to the appendix. Figure 3 As can be clearly seen from the attached diagram, the PE layer on the surface of the PE composite EPDM sealing strip has irregular particles and is relatively rough overall, with a noticeable grainy texture. Furthermore, the color of the PE layer differs from that of the EPDM substrate, which is more pronounced under sunlight or other bright light. This is because the two materials have different reflectivities, resulting in a generally lower-quality appearance for the sealing strip. In contrast, the sliding material produced by the technical solution in Example 12 is very smooth and has almost no color difference compared to the surrounding substrate. This is mainly because both the sliding material and the substrate are made of EPDM, resulting in good bonding and improving the overall appearance of the sealing strip.

[0111] For observations of the slip material thickness in Comparative Examples 5, 8, and Example 12, please refer to the appendix. Figure 4 As can be clearly seen from the photographs, PE(b) exhibits an uneven surface, with the lowest point only 43 μm high and the highest point reaching 156 μm, a difference of nearly four times. In contrast, the slip materials manufactured in Comparative Example 8(a) and Example 12(b) are generally smoother, with minimal variation in height. The variation in height between Comparative Example 8 and Example 12 is 46 μm, while the variation is only 28 μm, almost half the difference of Comparative Example 8. Furthermore, the cross-sectional views clearly show that Comparative Example 8 contains significantly more material. This large amount of added material will become stress concentration points during tensile testing, affecting the mechanical properties of the final product.

[0112] Before the corner bonding force test, refer to the aforementioned sealing strip corner joining method to join two sealing strips to form a corner. The materials used for the corner joining are EPDM and TPV, respectively. After cooling, the corner bonding force and high temperature corner bonding force are tested (the sample is placed at 90±3℃ and heated for 24 hours, and then tested immediately after being taken out). The test results are recorded in the table below, with the unit being N.

[0113]

[0114]

[0115] As seen in Comparative Example 1 in the table above, Comparative Example 1 uses pure EPDM rubber as the corner material. Since the two materials are the same, their compatibility is excellent, resulting in a significant advantage in corner bonding performance. However, when TPV is used as the corner material, the compatibility between the two is poor, leading to a significant decrease in corner bonding performance. Furthermore, looking at the high-temperature test results of Comparative Example 1, the performance of EPDM as the corner material does not decrease significantly at high temperatures. This is related to the excellent weather resistance of EPDM, while TPV has poor heat resistance, resulting in a significant decrease in corner bonding strength at high temperatures.

[0116] Further observation of Comparative Example 8 and Example 12 reveals that at room temperature, when EPDM is used as the corner material, the corner bonding strength of Example 12 is significantly better than that of Comparative Example 8. This is because the material in Comparative Example 8 is essentially a thermoplastic elastomer (TPV) material, resulting in poor adhesion between the two. In contrast, the sliding material in Example 12 uses EPDM as its base material, exhibiting better compatibility with the corner material. While the mechanical properties of Comparative Example 8 are superior to those of Example 12 when TPV is used as the corner material, the difference is not significant. Since corner bonding strength parameters are generally required to be ≥120N in OEM technical requirements, and ≥50N for some corner positions, Comparative Examples 7 and 8 can only be used for some corner positions, while Example 12 can be used for all corner positions. Furthermore, under high-temperature conditions, when using EPDM as the corner material, the corner bonding strength of Comparative Example 8 is close to the minimum technical requirement, while Example 12 is less affected by high temperatures. When using TPV as the corner material, the performance parameters of Example 12 and Comparative Example 8 are quite similar, and their susceptibility to high temperatures is almost identical.

[0117] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0118] Furthermore, it should be understood that although this specification describes embodiments and accompanying drawings, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wear-resistant rubber material for sealing strips, characterized in that: Composed of materials in the following parts by weight: EPDM: 100 copies; Ultra-high molecular weight polyethylene: 120-400 parts; Reinforcing agent: 0-35 parts; Processing oil: 3-25 parts.

2. The wear-resistant rubber material for sealing strips according to claim 1, characterized in that: Composed of materials in the following parts by weight: EPDM: 100 copies; Ultra-high molecular weight polyethylene: 200-350 parts; Reinforcing agent: 5-25 parts; Processing oil: 5-15 parts.

3. The wear-resistant rubber material for sealing strips according to claim 1 or 2, characterized in that: The reinforcing agent is selected from one or more of carbon black, silica, graphene, carbon fiber, carbon nanotubes, MXene, and calcium powder. The operating oil is selected from one or more of paraffin oil, liquid polybutadiene, and dioctyl sebate.

4. The wear-resistant rubber material for sealing strips according to claim 1 or 2, characterized in that: The material also includes 0.1-10 parts of a vulcanizing agent.

5. The wear-resistant rubber material for sealing strips according to claim 4, characterized in that: The vulcanizing agent is selected from one or more of sulfur, phenolic resin, EG-3, DCP, DTDC, and DCBP.

6. The method for preparing the rubber wear-resistant material for sealing strips according to any one of claims 1-5, characterized in that, include: After EPDM is mixed for 0.5-2 minutes, processing oil is added and mixed for another 0.5-2 minutes. Then, ultra-high molecular weight polyethylene and reinforcing agents are added and mixed to 100-130 degrees Celsius. The mixture is then discharged onto a two-roll mill for cooling. After filtration, strips are produced, crushed, and granulated.

7. A sealing strip, characterized in that: The sealing strip is provided with the rubber wear-resistant material as described in any one of claims 1-5.

8. The method for preparing the sealing strip according to claim 7, characterized in that: The EPDM rubber substrate is co-extruded with the aforementioned sealing strip rubber wear-resistant material, and then vulcanized and shaped to obtain the final product.

9. A means of transport, characterized in that: The sealing strip as described in claim 7 is provided.

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