Multi-stage composite production process of EPDM rubber sealing element

Abstract

The invention discloses a multi-stage composite production process of an EPDM (Ethylene-Propylene-Diene Monomer) rubber sealing element, and relates to the technical field of rubber sealing elements, and the multi-stage composite production process is technically characterized by comprising the following steps of: 1, extruding: putting EPDM rubber into a single-screw extruder, heating to 180-200 DEG C to be in a molten state, and conveying the EPDM rubber to a spinning machine through a metering pump; 2, spinning: forming filaments by the melt through a spinning machine consisting of a filter screen, a distribution plate and a spinning plate, drawing the filaments into a net forming area through hot air, and compounding the filaments with polyester fibers to form a semi-finished product; 3, glue spraying: coating water-soluble glue on the front and back surfaces of the semi-finished product, and compounding double-layer non-woven fabric or release paper or cotton paper; fourthly, slitting and die pressing are conducted, and after rewinding and slitting are conducted, a final product is formed through die pressing of a punching machine according to requirements; 5, inspecting and leaving factory, namely inspecting and leaving factory after packaging; the sealing element production device can achieve environment-friendly, efficient and stable sealing element production.

Description

Technical Field

[0001] This invention relates to the field of rubber seal technology, and in particular to a multi-stage composite production process for EPDM rubber seals. Background Technology

[0002] In the automotive industry, rotary seals in the powertrain and transmission systems are critical components ensuring the normal operation of vehicles. Their quality and performance are paramount, directly impacting the overall reliability and lifespan of the vehicle. With the continued rapid development of the automotive industry, the performance requirements for seals are also increasing. Today's seals not only need excellent sealing performance to prevent leakage of various liquids and gases inside the vehicle, but also need to exhibit outstanding performance in high-temperature resistance, wear resistance, and corrosion resistance to meet the operational needs of vehicles under various complex conditions.

[0003] Currently, the production of sealing components mainly employs processes using raw materials such as nitrile rubber, PVC, EPDM rubber, and polyester fiber, and utilizing equipment such as internal mixers and open mills. However, this existing production process has revealed several problems that urgently need to be addressed. In the batching stage, both primary and secondary batching rely on manual weighing and feeding. During manual weighing, powdery raw materials generate dust, which is emitted in an unorganized manner. This not only severely pollutes the production environment but also poses a threat to the health of operators. Moreover, manual operation is inefficient and makes it difficult to ensure the accuracy of batching, thus affecting the stability of the sealing component product quality.

[0004] Problems also exist in other stages such as internal mixing, open mixing, foaming, and extrusion. Internal mixing and open mixing are physical processes, but they generate significant noise, causing noise pollution to the surrounding environment. Furthermore, these processes produce mixed waste gas (non-methane hydrocarbons), which, if not effectively treated, will pollute the atmosphere. The foaming process uses a hot air circulation foaming device heated by natural gas, producing foaming waste gas containing various harmful gases, as well as natural gas combustion waste gas. Its complex composition means that direct emission will severely pollute the atmosphere and harm human health. The extrusion stage generates extrusion waste gas (non-methane hydrocarbons) and noise, affecting the environment and operators. In addition, multiple stages throughout the entire production process generate noise; prolonged exposure to high-noise environments can affect the physical and mental health of operators and the lives of nearby residents. The punching, forming, and slitting molding processes produce defective products and scraps; if not properly recycled, this will lead to resource waste and increased production costs. In summary, existing automotive sealing component manufacturing processes have many shortcomings in terms of environmental protection, production efficiency, and product quality. There is an urgent need to develop a more environmentally friendly, efficient, and stable manufacturing process to meet the growing demand for sealing components in the automotive industry. Summary of the Invention

[0005] In order to at least solve one of the above-mentioned technical problems, the purpose of this invention is to provide a multi-stage composite production process for EPDM rubber seals, so as to achieve environmentally friendly, efficient and stable production of seals.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A multi-stage composite manufacturing process for EPDM rubber seals includes the following steps:

[0008] The first step, extrusion: EPDM rubber is fed into a single screw extruder through a raw material conveying device and heated to 180-200℃ until the EPDM rubber is in a molten state. The melt from the screw extruder is sent to the spinneret by a metering pump.

[0009] The second step is spinning: the melt passes through the small holes on the spinneret, which consists of a filter screen, a distribution plate, and a spinneret plate, to form melt filaments. After being ejected, the melt filaments are drawn into the web-forming zone by the hot air blown out by the air heater. The polyester fibers and the melt filaments ejected from the spinneret are combined and formed into a semi-finished product in the web-forming zone by taking advantage of the different melting points of the two fibers.

[0010] The third step is to apply adhesive: water-soluble adhesive is applied to the front and back of the semi-finished product using a coating machine to coat double-layer non-woven fabric, release paper, or cotton paper.

[0011] The fourth step is slitting and pressing: After being rewound by the rewinding machine and slitting by the slitting machine, the final product is formed by pressing with a punching machine according to customer requirements.

[0012] Step 5, Inspection before shipment: Package the product and inspect it before shipment.

[0013] Preferably, in the second step of the spinning process, the spinneret has a 0.32mm orifice and is made of stainless steel.

[0014] Preferably, multiple temperature sensors inside the extruder monitor the temperature in real time. When the temperature is below 180°C, the heating power is automatically increased; when the temperature is above 200°C, the heating power is automatically reduced or the cooling device is turned on to lower the temperature.

[0015] Preferably, during the second step of spinning, the temperature of the hot air blown out by the air heater is controlled at 220-250℃, and the hot air velocity is maintained at 5-8m / s. The hot air temperature and velocity are precisely controlled by adjusting the heating power of the air heater and the speed of the fan. The web forming area is equipped with a temperature regulating device to maintain the temperature of the web forming area at 150-180℃.

[0016] Preferably, the raw material conveying device includes a frame, a drive device fixedly connected to the side wall of the frame, a transmission roller fixedly connected to the output end of the drive device, a conveyor belt drivingly connected to the side wall of the transmission roller, a fixed frame fixedly connected to the side wall of the frame, and an adjustment component disposed inside the fixed frame, the adjustment component including:

[0017] The motor has a rotating frame fixedly connected to its output end, a feeding cylinder fixedly connected to the inner wall of the rotating frame, and a baffle slidably connected to the side wall of the rotating frame.

[0018] An adjusting shaft, wherein a hinge rod one is hinged to the side wall of the adjusting shaft, and a hinge rod two is hinged to the end face of the hinge rod one;

[0019] A feeding hopper, wherein a guide plate is fixedly connected to the side wall of the feeding hopper, a connecting rod is fixedly connected to the side wall of the feeding hopper, and a guide plate is fixedly connected to the end face of the connecting rod;

[0020] The feeding pipe has a guide plate fixedly connected to its side wall.

[0021] Preferably, the motor is fixedly connected to the side wall of the fixed frame, and the baffle is located on the side of the feed cylinder near the outer wall of the rotating frame.

[0022] Preferably, the rotating frame includes two coaxial rings, and the feeding cylinder is located on the inner wall of the outer ring, enabling quantitative and timed feeding.

[0023] Preferably, the adjusting shaft is rotatably connected to the rotating frame, the second hinge rod is inserted into the inner ring, and a disc is fixedly connected to the end face of the second hinge rod, the disc being inserted into the feeding cylinder.

[0024] Preferably, the feeding hopper is fixedly connected to the inner wall of the fixed frame, the bottom of the feeding hopper is movably connected to the outer wall of the rotating frame, the first guide plate is movably connected to the baffle, and the second guide plate is movably connected to the baffle.

[0025] Preferably, the feeding pipe is fixedly connected to the inner wall of the fixed frame, and the guide plate three is movably connected to the baffle, the guide plate three pushing the baffle away from below the feeding cylinder.

[0026] Preferably, the side wall of the rotating frame is fixedly connected to an installation strip, the side wall of the installation strip is threadedly connected to an adjusting bolt, the end face of the adjusting bolt is fixedly connected to an insert rod, and the insert rod is inserted into the adjusting shaft.

[0027] Preferably, during the first extrusion process, the screw speed of the single-screw extruder is adjustable, with an adjustment range of 50-150 r / min.

[0028] The present invention has the following beneficial effects:

[0029] I. Reduced Dust Pollution: Traditional processes generate dust through manual weighing of powdered raw materials, resulting in fugitive emissions that pollute the production environment and endanger the health of operators. This process, however, eliminates the need for manual weighing and feeding, thus avoiding dust pollution in this stage.

[0030] II. Reducing Waste Gas Emissions: Traditional processes generate mixed waste gas (non-methane hydrocarbons) during internal mixing and open milling, foaming waste gas containing various harmful gases and natural gas combustion waste gas during foaming, and extrusion waste gas (non-methane hydrocarbons) during extrusion. Direct emissions of these gases severely pollute the atmosphere and endanger human health. This process avoids these highly polluting stages, reducing waste gas emissions at the source and lowering pollution levels.

[0031] Third, reducing noise pollution: Traditional processes generate significant noise during multiple stages such as internal mixing, open mixing, and extrusion, impacting the surrounding environment and the physical and mental health of operators. This process does not detail these high-noise stages, suggesting that it reduces noise pollution to some extent.

[0032] IV. Automated Temperature Control: Multiple temperature sensors are installed inside the extruder to monitor the temperature in real time. When the temperature is below 180℃, the heating power is automatically increased; when the temperature is above 200℃, the heating power is automatically reduced or the cooling device is activated to lower the temperature. This automated temperature control method can quickly and accurately adjust the temperature, avoiding the lag and inaccuracy of manual adjustment, and improving the stability and efficiency of the production process.

[0033] V. Precise Control of Spinning Parameters: During the spinning process, the spinneret uses a 0.32mm aperture and is made of stainless steel. The temperature of the hot air blown from the air heater is controlled at 220-250℃, and the hot air velocity is maintained at 5-8m / s. The hot air temperature and velocity are precisely controlled by adjusting the heating power of the air heater and the speed of the fan. A temperature regulation device is installed in the web forming area to maintain the temperature of the web forming area at 150-180℃. These precise parameter controls ensure the stability and consistency of the spinning process, reduce the defect rate, and improve production efficiency.

[0034] VI. Adjustable Screw Speed: During the extrusion process, the screw speed of the single-screw extruder is adjustable, with an adjustment range of 50-150 r / min. Flexible adjustment of the screw speed according to different production needs and raw material characteristics can optimize the extrusion process and improve production efficiency.

[0035] VII. Precise Batching and Molding: Through automated equipment and precise process parameter control, such as extruder temperature control and spinneret parameter control, the stability and consistency of each production stage can be guaranteed, thereby ensuring the consistent quality of the final product. This avoids the product quality fluctuations caused by inaccurate manual batching in traditional processes.

[0036] 8. Rigorous Inspection Process: The inspection process before shipment includes appearance inspection, dimensional inspection, and performance inspection. Through comprehensive and rigorous inspection, unqualified products can be identified and eliminated in a timely manner, ensuring that the quality of products leaving the factory meets the standard requirements.

[0037] IX. Advantages of Material Composites: During the spinning process, polyester fibers are combined with the molten filaments extruded from the spinneret. Utilizing the different melting points of the two fibers, they are web-formed in the web-forming zone to create a semi-finished product. This material composite method combines the advantages of EPDM rubber and polyester fibers, giving the seals both the sealing properties, high-temperature resistance, and corrosion resistance of EPDM rubber, and the strength and wear resistance of polyester fibers, thus improving the overall performance of the seals.

[0038] 10. Multi-stage Collaborative Production: This process involves the orderly combination of multiple stages, including extrusion, spinning, adhesive spraying, slitting and molding, and inspection before shipment. Each stage works in concert to form a complete production system. For example, extrusion provides the molten raw material for subsequent spinning; the semi-finished product formed by spinning is then coated with adhesive and combined with other materials before slitting and molding; finally, inspection ensures product quality. This multi-stage collaborative production method fully leverages the advantages of each stage, improving production efficiency and product quality. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a process flow diagram of an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the main structure of the raw material conveying device for the invention;

[0042] Figure 3 A schematic diagram of the adjusting component structure of the raw material conveying device for the invention;

[0043] Figure 4 A schematic cross-sectional view of the rotating frame structure of the raw material conveying device for the invention;

[0044] Figure 5 for Figure 4 Schematic diagram of the structure of region A in the middle;

[0045] Figure 6 for Figure 4 Schematic diagram of the structure of region B in the middle;

[0046] Figure 7 for Figure 4 Schematic diagram of the structure of region C. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] Extrusion stage

[0050] EPDM rubber is fed into a single-screw extruder via a raw material conveying device, with the screw speed set to 50 r / min. Temperature is monitored in real-time by a temperature sensor and heated to 180℃ to molten the EPDM rubber. The melt from the screw extruder is then sent to a spinneret via a metering pump.

[0051] Spinning stage

[0052] A stainless steel spinneret with an aperture of 0.32 mm is selected. The molten material passes through small holes in the spinneret, which consists of a filter screen, a distribution plate, and the spinneret, forming molten filaments. The hot air temperature from the air heater is set to 220℃, and the air velocity is maintained at 5 m / s, precisely controlled by adjusting the heating power of the air heater and the speed of the fan. After being ejected, the molten filaments are drawn into the web-forming zone by the hot air, where the temperature is maintained at 150℃. Polyester fibers and the molten filaments ejected from the spinneret are combined, utilizing their different melting points to form a web in the web-forming zone, creating a semi-finished product.

[0053] Glue spraying stage

[0054] On the front and back sides of the semi-finished product, a double-layer nonwoven fabric is coated with polyvinyl alcohol water-soluble adhesive using a coating machine.

[0055] Cutting and molding stage

[0056] After being rewound by a rewinding machine and slit by a slitting machine, the final product is formed by pressing with a punching die according to customer requirements.

[0057] Inspection and delivery stage

[0058] The product undergoes visual inspection, dimensional inspection, and performance inspection. Visual inspection checks the product surface for defects, bubbles, etc.; dimensional inspection uses professional measuring tools to measure the product's length, width, thickness, and other dimensions to ensure they meet standards; performance inspection includes sealing tests (detecting leaks under specific pressure), high-temperature resistance tests (placing the product in a high-temperature environment for a period of time and observing performance changes), and wear resistance tests (simulating wear conditions using a friction testing machine to measure the amount of wear on the product), etc.

[0059] like Figures 2-7 As shown, the raw material conveying device includes a frame 1. A drive device 2 is fixedly connected to the side wall of the frame 1. A transmission roller is fixedly connected to the output end of the drive device 2. A conveyor belt 3 is drivenly connected to the side wall of the transmission roller. A fixed frame 4 is fixedly connected to the side wall of the frame 1. An adjustment component 5 is provided inside the fixed frame 4. The adjustment component 5 includes a motor 501, a rotating frame 502, an adjustment shaft 503, a first hinge rod 504, a second hinge rod 505, a feeding cylinder 506, a baffle 507, a feeding hopper 508, a first guide plate 509, a connecting rod 510, a second guide plate 511, a discharge pipe 512, and a third guide plate 513.

[0060] In one embodiment of the present invention, a motor 501 is fixedly connected to the side wall of a fixed frame 4, and a rotating frame 502 is fixedly connected to the output end of the motor 501. A feeding cylinder 506 is fixedly connected to the inner wall of the rotating frame 502, and a baffle 507 is slidably connected to the side wall of the rotating frame 502. The baffle 507 is located on the side of the feeding cylinder 506 near the outer wall of the rotating frame 502. The rotating frame 502 includes two coaxial rings, and the feeding cylinder 506 is located on the inner wall of the outer ring. The feeding cylinder 506 realizes quantitative and timed feeding.

[0061] The adjusting shaft 503 is rotatably connected to the rotating frame 502. The side wall of the adjusting shaft 503 is hinged with a first hinge rod 504. The end face of the first hinge rod 504 is hinged with a second hinge rod 505. The second hinge rod 505 is inserted into the inner ring. The end face of the second hinge rod 505 is fixedly connected to a disc. The disc is inserted into the feeding cylinder 506.

[0062] The feeding hopper 508 is fixedly connected to the inner wall of the fixed frame 4. A guide plate 509 is fixedly connected to the side wall of the feeding hopper 508. A connecting rod 510 is fixedly connected to the side wall of the feeding hopper 508. A guide plate 511 is fixedly connected to the end face of the connecting rod 510. The bottom of the feeding hopper 508 is movably connected to the outer wall of the rotating frame 502. The guide plate 509 is movably connected to the baffle 507. The guide plate 511 is movably connected to the baffle 507.

[0063] The feeding pipe 512 is fixedly connected to the inner wall of the fixed frame 4. The side wall of the feeding pipe 512 is fixedly connected to the guide plate 3 513. The guide plate 3 513 is movably connected to the baffle 507. The guide plate 3 513 pushes the baffle 507 away from the bottom of the feeding cylinder 506.

[0064] Motor 501 drives rotating frame 502 to rotate, so that rotating frame 502 and feeding cylinder 506 pass under feeding hopper 508. Rubber particles inside feeding hopper 508 fall into feeding cylinder 506. Then, as rotating frame 502 rotates, rubber particles fall into discharge pipe 512 and then onto conveyor belt 3, realizing quantitative feeding. This helps to stabilize subsequent mixing, calendering or extrusion processes, ensuring more accurate raw material ratios and reducing fluctuations during the production of sealing parts.

[0065] Rotating the adjusting shaft 503 causes the hinge rod 1 504 and hinge rod 2 505 to move. The hinge rod 2 505 pushes the disc, changing the position of the disc in the feeding cylinder 506, thereby adjusting the feeding amount and making the feeding amount more precise. Through adjustment, production line requirements can be quickly switched to adapt to different formulas and processes, improving production flexibility and reducing downtime caused by changing equipment or molds.

[0066] During the rotation of the rotating frame 502, the second guide plate 511 pushes the baffle 507 to block the outlet of the feed cylinder 506 containing rubber granules. The first guide plate 509 and the third guide plate 513 push the baffle 507 to open the opening of the feed cylinder 506. When the feed cylinder 506 is at the bottom of the upper hopper 508 or the top of the lower pipe 512, the rubber granules can freely enter and exit the feed cylinder 506. When the feed cylinder 506 is in a non-discharge position during rotation, the outlet is blocked by the baffle 507, and the rubber granules will not fall off prematurely, avoiding contamination of the equipment or waste of raw materials. Only when the cylinder opening is below the upper hopper 508 or above the lower pipe 512 is the baffle 507 pushed open by the first guide plate 509 and the third guide plate 513, and the granules can freely enter and exit. This achieves opening only at designated positions, ensuring the accuracy of feeding and improving the uniformity and stability of feeding.

[0067] Compared to a fixed baffle ring, which rubs against particles for a long time, the fixed ring is prone to wear and jamming. The baffle 507, which rotates with the feed cylinder 506, only moves at the moment of opening and closing, so the friction is concentrated and controllable, making it less likely to accumulate material, reducing maintenance costs, and reducing material accumulation and wear.

[0068] In addition, a mounting strip 8 is fixedly connected to the side wall of the rotating frame 502, and an adjusting bolt 6 is threadedly connected to the side wall of the mounting strip 8. A plug rod 7 is fixedly connected to the end face of the adjusting bolt 6. The plug rod 7 is inserted into the adjusting shaft 503. The adjusting bolt 6 is threadedly connected to the mounting strip 8, which allows for precise control of the position of the plug rod 7, thereby controlling the insertion depth or angle of the adjusting shaft 503. The threaded drive has self-locking properties, preventing the plug rod 7 from loosening from the adjusting shaft 503 due to vibration or rotation, thus ensuring stability and safety during the adjustment process.

[0069] In this invention, during use, the motor 501 drives the rotating frame 502 to rotate, causing the rotating frame 502 and the feeding cylinder 506 to pass below the feeding hopper 508. Rubber particles inside the feeding hopper 508 fall into the feeding cylinder 506. Then, as the rotating frame 502 rotates, the rubber particles fall into the discharge pipe 512 and onto the conveyor belt 3. Rotating the adjusting shaft 503 causes the first hinge rod 504 and the second hinge rod 505 to move. The second hinge rod 505 pushes the disc, changing the disc's position during feeding. The position inside the cylinder 506 allows for adjustment of the feeding amount, making the discharge more precise. When the feeding cylinder 506 is in a non-discharge position during rotation, the outlet is blocked by the baffle 507, preventing rubber granules from falling prematurely and avoiding contamination of the equipment or waste of raw materials. Only when the cylinder opening is below the hopper 508 or above the discharge pipe 512 is the baffle 507 pushed open by the guide plate 1 509 and the guide plate 3 513, allowing the granules to freely enter and exit. This ensures that the opening is only at a designated position, guaranteeing the accuracy of the feeding.

[0070] Example 2

[0071] Extrusion stage

[0072] EPDM rubber is fed into a single-screw extruder, with the screw speed set to 100 r / min. It is heated to 190°C to melt the EPDM rubber, and the melt is then pumped to a spinneret via a metering pump.

[0073] Spinning stage

[0074] The same 0.32mm aperture stainless steel spinneret is used. The temperature of the hot air blown out by the air heater is controlled at 235℃, and the hot air velocity is maintained at 6.5m / s. The temperature of the web forming zone is maintained at 165℃. Polyester fibers and melt filaments are combined to form a semi-finished product.

[0075] Glue application, slitting and molding, inspection and shipment stages

[0076] The procedures for applying adhesive, cutting and molding, and inspection before shipment are the same as in Example 1.

[0077] Example 3

[0078] Extrusion stage

[0079] EPDM rubber is fed into a single-screw extruder, and the screw speed is adjusted to 150 r / min. It is heated to 200℃ to melt the rubber, and then sent to the spinneret via a metering pump.

[0080] Spinning stage

[0081] A stainless steel spinneret with a 0.32mm aperture is used. The air heater hot air temperature is set to 250℃, and the hot air velocity is maintained at 8m / s. The temperature in the web-forming zone is maintained at 180℃. Polyester fibers and melt filaments are combined to form a semi-finished product.

[0082] Glue application, slitting and molding, inspection and shipment stages

[0083] The procedures for applying adhesive, cutting and molding, and inspection before shipment are the same as in Example 1.

[0084] The experimental test results are shown in Table 1.

[0085] Table 1 Experimental Data Table

[0086] Experimental Project Example 1 Example 2 Example 3 Screw speed during extrusion (r / min) 50 100 150 Extrusion temperature (°C) 180 190 200 Hot air temperature during the spinning stage (°C) 220 235 250 Hot air velocity during the spinning stage (m / s) 5 6.5 8 Temperature in the web-forming area (°C) 150 165 180 Leakage rate (%) in sealing test 0.02 0.015 0.01 Change rate of high temperature resistance performance (%) 2 1.5 1 Wear resistance test: Wear amount (mg) 10 8 6 Production efficiency (pieces / hour) 80 90 95

[0087] Experimental data analysis

[0088] Sealing test

[0089] Technical principle: Precise control of parameters such as temperature and screw speed during the extrusion and spinning stages ensures that the EPDM rubber is fully melted and uniformly compounded with polyester fibers. Appropriate hot air temperature, air velocity, and web-forming zone temperature guarantee the fiber tension and compounding effect, resulting in a denser structure for the seal.

[0090] Technical Results: Experimental data shows that as parameters such as extrusion temperature and spinneret hot air temperature increase within a certain range, the leakage rate in the sealing test gradually decreases. Example 3 exhibits the lowest leakage rate of 0.01%, indicating that adjusting process parameters appropriately can significantly improve the sealing performance of the seals and reduce the risk of leakage.

[0091] High temperature resistance test

[0092] Technical Principle: Higher extrusion and hot air temperatures help EPDM rubber molecular chains to better stretch and cross-link. Simultaneously, when combined with polyester fibers, the high melting point of the polyester fibers enhances the stability of the seals in high-temperature environments. Proper temperature control in the web-forming zone ensures the smooth progress of the composite process, optimizing material properties.

[0093] Technical Results: Experimental data show that as the parameters increase, the rate of change in high-temperature resistance performance gradually decreases. Example 3 exhibits the lowest performance change rate, at 1%, indicating that optimizing process parameters can improve the performance stability of the seal under high-temperature conditions and reduce performance degradation caused by high temperatures.

[0094] Abrasion resistance test

[0095] Technical principle: Appropriate screw speed, extrusion temperature, and spinneret parameters enable EPDM rubber and polyester fibers to fully fuse, forming a uniform and dense structure. This structure enhances the surface hardness and wear resistance of the seal, reducing material loss during the wear process.

[0096] Technical Results: The data shows that Example 3 exhibited the lowest wear amount, at 6mg. This indicates that adjusting process parameters appropriately can effectively improve the wear resistance of the seals and extend their service life.

[0097] Production efficiency

[0098] Technical principle: Increasing the screw speed accelerates the extrusion rate of EPDM rubber, while proper temperature control ensures the stability and continuity of the extrusion process. Precise control of hot air temperature and velocity during the spinneret stage makes the fiber compounding process more efficient, reducing downtime and adjustment time during production.

[0099] Technical Results: Experiments show that production efficiency gradually increases with the increase of parameters such as screw speed. Example 3 achieved the highest production efficiency, reaching 95 pieces / hour, indicating that optimizing process parameters can significantly improve the production efficiency of seals and meet the needs of large-scale production.

[0100] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A multi-stage composite production process for EPDM rubber seals, characterized in that, Includes the following steps: The first step, extrusion: EPDM rubber is fed into a single screw extruder through a raw material conveying device and heated to 180-200℃ until the EPDM rubber is in a molten state. The melt from the screw extruder is sent to the spinneret by a metering pump. The second step is spinning: the melt passes through the small holes on the spinneret, which consists of a filter screen, a distribution plate, and a spinneret plate, to form melt filaments. After being ejected, the melt filaments are drawn into the web-forming zone by the hot air blown out by the air heater. The polyester fibers and the melt filaments ejected from the spinneret are combined and formed into a semi-finished product in the web-forming zone by taking advantage of the different melting points of the two fibers. The third step is to apply adhesive: water-soluble adhesive is applied to the front and back of the semi-finished product using a coating machine to coat double-layer non-woven fabric, release paper, or cotton paper. The fourth step is slitting and pressing: After being rewound by the rewinding machine and slitting by the slitting machine, the final product is formed by pressing with a punching machine according to customer requirements. Step 5, Inspection before shipment: Package the product and inspect it before shipment.

2. The multi-stage composite production process for EPDM rubber seals according to claim 1, characterized in that, In the second step of the spinning process, the spinneret has a 0.32mm orifice and is made of stainless steel.

3. The multi-stage composite production process for EPDM rubber seals according to claim 1, characterized in that, Multiple temperature sensors inside the extruder monitor the temperature in real time. When the temperature is below 180°C, the heating power is automatically increased; when the temperature is above 200°C, the heating power is automatically reduced or the cooling device is turned on to cool down.

4. The multi-stage composite production process for EPDM rubber seals according to claim 3, characterized in that, During the second step of spinning, the temperature of the hot air blown out by the air heater is controlled at 220-250℃, and the hot air speed is maintained at 5-8m / s. The hot air temperature and speed are precisely controlled by adjusting the heating power of the air heater and the speed of the fan. The web forming area is equipped with a temperature regulating device to maintain the temperature of the web forming area at 150-180℃.

5. The multi-stage composite production process for EPDM rubber seals according to claim 1, characterized in that, The raw material conveying device includes a frame (1), a drive device (2) is fixedly connected to the side wall of the frame (1), a transmission roller is fixedly connected to the output end of the drive device (2), and a conveyor belt (3) is drivenly connected to the side wall of the transmission roller. The device is characterized in that a fixed frame (4) is fixedly connected to the side wall of the frame (1), and an adjustment component (5) is provided inside the fixed frame (4). The adjustment component (5) includes: A motor (501) is provided, the output end of which is fixedly connected to a rotating frame (502), the inner wall of which is fixedly connected to a feeding cylinder (506), and the side wall of which is slidably connected to a baffle (507). Adjusting shaft (503), the side wall of the adjusting shaft (503) is hinged to a hinge rod one (504), and the end face of the hinge rod one (504) is hinged to a hinge rod two (505). A feeding hopper (508) is provided with a guide plate (509) fixedly connected to its side wall, a connecting rod (510) fixedly connected to its side wall, and a guide plate (511) fixedly connected to the end face of the connecting rod (510). The feeding pipe (512) has a guide plate (513) fixedly connected to its side wall.

6. The multi-stage composite production process for EPDM rubber seals according to claim 5, characterized in that: The motor (501) is fixedly connected to the side wall of the fixed frame (4), and the baffle (507) is located on the side of the feed cylinder (506) near the outer wall of the rotating frame (502).

7. The multi-stage composite production process for EPDM rubber seals according to claim 5, characterized in that: The rotating frame (502) includes two coaxial rings, and the feed cylinder (506) is located on the inner wall of the outer ring.

8. The multi-stage composite production process for EPDM rubber seals according to claim 7, characterized in that: The adjusting shaft (503) is rotatably connected to the rotating frame (502), the second hinge rod (505) is inserted into the inner ring, and a disc is fixedly connected to the end face of the second hinge rod (505), and the disc is inserted into the feeding cylinder (506).

9. The multi-stage composite production process for EPDM rubber seals according to claim 5, characterized in that: The feeding hopper (508) is fixedly connected to the inner wall of the fixed frame (4), the bottom of the feeding hopper (508) is movably connected to the outer wall of the rotating frame (502), the first guide plate (509) is movably connected to the baffle (507), and the second guide plate (511) is movably connected to the baffle (507).

10. The multi-stage composite production process for EPDM rubber seals according to claim 5, characterized in that: The feeding pipe (512) is fixedly connected to the inner wall of the fixed frame (4), and the guide plate (513) is movably connected to the baffle (507); the side wall of the rotating frame (502) is fixedly connected to the mounting strip (8), the side wall of the mounting strip (8) is threadedly connected to the adjusting bolt (6), the end face of the adjusting bolt (6) is fixedly connected to the insert rod (7), and the insert rod (7) is inserted into the adjusting shaft (503).

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