High-recovery elastic sealing strip material of washing machine and preparation method of high-recovery elastic sealing strip material

Abstract

The invention discloses a high-recovery elastic sealing strip material of a washing machine and a preparation method of the high-recovery elastic sealing strip material, and relates to the technical field of sealing strips of washing machines. 10 to 40 parts of semi-reinforcing carbon black; 10 to 40 parts of fast extruding furnace black; 5-30 parts of a modified organic elastic material; 0.5 to 3 parts of an organic silane coupling agent; 0.5 to 3 parts of a vulcanizing agent; 0.5 to 5 parts of a vulcanization accelerator; 1 to 10 parts of an active agent; 5-30 parts of a plasticizer; 0.5 to 3 parts of an anti-aging agent; and 0-30 parts of a filler. The sealing strip material is particularly suitable for washing machine door seals and can also be popularized to other household appliances and industrial fields needing high-elasticity and long-life sealing.

Description

Technical Field

[0001] This invention relates to the field of washing machine sealing strip technology, and in particular to a high-recovery elastic sealing strip material for washing machines and its preparation method. Background Technology

[0002] Washing machines operate in humid, hot, and highly alkaline environments, requiring their door / drum seal rubber sealing strips to possess excellent comprehensive performance to meet the demands of waterproofing, leak prevention, detergent corrosion resistance, and long-term dynamic sealing. This necessitates that the sealing strip material possess high elasticity, low compression set, good mechanical strength, aging resistance, and temperature resistance.

[0003] Currently, the industry mainly uses materials such as PVC, modified PVC, EPDM, TPV / TPE / TPR, and silicone. However, traditional sealing strips still face the following limitations when dealing with the high temperature, high pressure, and frequent opening and closing dynamic conditions of washing machines: Traditional formulations struggle to balance high elasticity, low compression set, and high strength. While high filler can reduce costs, it often sacrifices elasticity and dimensional stability, increases compression set, and affects seal life.

[0004] After the sealing strip is extruded, it is usually "rapidly cooled" using a long water tank or spray pipe. This method is prone to warping and deformation at the point of internal stress concentration, resulting in uneven product cross-sectional dimensions, poor appearance quality, and may affect the long-term elastic recovery ability due to the freezing of internal stress. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-recovery elastic sealing strip material for washing machines and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A high-resilience sealing strip material for washing machines comprises the following raw materials in parts by weight: EPDM raw rubber: 100 parts; Semi-reinforcing carbon black: 10-40 parts; Quickly press out carbon black: 10-40 parts; Modified organic elastic material: 5-30 parts; Organosilane coupling agent: 0.5-3 parts; Vulcanizing agent: 0.5-3 parts; Vulcanization accelerator: 0.5-5 parts; Surfactant: 1-10 parts; Plasticizer: 5-30 parts; Anti-aging agent: 0.5-3 parts; Filler: 0-30 parts.

[0007] As a further improvement of the present invention, the EPDM raw rubber satisfies the following: Mooney viscosity ML(1+4) ≥ 60 at 125℃; The third monomer is ethylene norbornene (ENB), with a mass percentage of ≥5%; The ethylene content is 50%-60% by mass.

[0008] As a further improvement of the present invention, the modified organic elastic material is one or more modified products selected from acrylate rubber (ACM), nitrile rubber (NBR), chloroprene rubber (CR), hydrogenated nitrile rubber (HNBR), thermoplastic elastomer (TPE) or polyurethane elastomer (TPU).

[0009] As a further improvement of the present invention, the organosilane coupling agent has the general formula R–Si(OR')3, wherein R is an organic functional group containing amino, epoxy, mercapto or vinyl groups, and R' is a C1-C4 alkyl group.

[0010] A method for preparing the sealing strip material, using a sealing strip material preparation apparatus, includes the following steps: Step 1: Weigh out each ingredient according to the recipe; Step 2: Mix the raw materials from Step 1 at 80-120℃ to obtain the compounded rubber. Step 3: Extrude the compound obtained in Step 2 at 150-220℃ and simultaneously vulcanize it to obtain the sealing strip blank; Step four: Cool and shape the sealing strip blank and output it.

[0011] As a further improvement of the present invention, the sealing strip material preparation device includes a mixer, an extrusion vulcanizing machine, and a mounting box located at the output end of the extrusion vulcanizing machine. An mounting cylinder is fixed to the upper end of the mounting box. Three mounting rings are rotatably mounted inside the mounting cylinder. Two fixing rods are fixed between the three mounting rings. A pre-cooling mechanism, a cooling mechanism, and a drying mechanism are sequentially provided on the three mounting rings. The pre-cooling mechanism is close to the extrusion vulcanizing machine, and the drying mechanism is away from the extrusion vulcanizing machine. The pre-cooling mechanism includes a first annular tube fixed to the side wall of the mounting ring. Multiple evenly distributed air jet pipes are connected to the side wall of the first annular tube. A first connecting pipe is connected to the side wall of the first annular tube, and the end of the first connecting pipe away from the first annular tube is connected to... The system includes a first fan, an intake pipe connected to the input end of the first fan, and an end of the intake pipe away from the first fan connected to the middle of the upper side wall of the mounting cylinder. The cooling mechanism includes a second annular pipe fixed to the side wall of the mounting ring, with multiple evenly distributed water spray pipes connected to the side wall of the second annular pipe. A second connecting pipe is connected to the side wall of the second annular pipe, and a water pump is connected to the end of the second connecting pipe away from the second annular pipe. The drying mechanism includes a third annular pipe fixed to the side wall of the mounting ring, with evenly distributed drying pipes connected to the side wall of the third annular pipe. A third connecting pipe is connected to the side wall of the third annular pipe, and a second fan is connected to the end of the third connecting pipe away from the third annular pipe. The mounting cylinder is equipped with a swing mechanism connected to one of the mounting rings.

[0012] As a further improvement of the present invention, the swing mechanism includes a device plate fixed to the side wall of the mounting cylinder, a rotating shaft rotatably connected to the side wall of the device plate, a swing toothed plate fixedly sleeved on the side wall of the rotating shaft, a toothed ring meshing with the swing toothed plate fixed on the side wall of the mounting ring, a sliding groove penetrating the side wall of the swing toothed plate, a motor mounted on the side wall of the device plate above the rotating shaft, a turntable fixedly connected to the output shaft of the motor, a sliding rod fixedly connected to the edge of the turntable, and the sliding rod slidably inserted into the inside of the sliding groove.

[0013] As a further improvement of the present invention, a water collection hopper communicating with the mounting cylinder is fixed to the lower side wall of the mounting cylinder, and a return water pipe is connected to the bottom of the water collection hopper, the return water pipe passing through the bottom of the mounting box.

[0014] As a further improvement of the present invention, support legs are fixed at the four corners of the bottom of the mounting box.

[0015] The beneficial effects of this invention are: By selecting specific EPDM, compounding fillers, introducing modified organic elastic materials, and adopting a semi-effective vulcanization system, a balance between high elasticity, low compression set, and excellent mechanical properties has been achieved.

[0016] By setting up a pre-cooling mechanism, a cooling mechanism, and a drying mechanism inside the mounting cylinder, a gradient treatment of the high-temperature sealing strip blank is achieved, avoiding the internal stress generated by the blank due to drastic cooling. This makes the temperature gradient of the sealing strip more gradual during the cooling process, which is conducive to maintaining dimensional stability and cross-sectional shape consistency, thereby improving the dimensional accuracy and appearance quality of the final product.

[0017] The oscillating mechanism enables the airflow and liquid flow during the pre-cooling, cooling and drying processes to form dynamic, multi-angle convection scouring relative to the sealing strip blank. This avoids the stress concentration or warping deformation problems caused by uneven local cooling of the blank under the traditional fixed spraying method, significantly improving cooling efficiency and the uniformity of cross-sectional temperature distribution, which helps to improve the mechanical properties and dimensional stability of the material. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the sealing strip material preparation device proposed in this invention; Figure 2 This is a schematic diagram of the mounting ring, fixing rod, pre-cooling mechanism, cooling mechanism, drying mechanism, and swing mechanism of the sealing strip material preparation device proposed in this invention; Figure 3 This is a schematic diagram of the device plate, rotating shaft, swing toothed plate, and slide groove of the sealing strip material preparation device proposed in this invention. Figure 4 This is a schematic diagram of the structure of the sealing strip material preparation device proposed in this invention, including the device plate, rotating shaft, motor, turntable, and slide rod.

[0019] In the diagram: 1 Internal mixer, 2 Extrusion vulcanizing machine, 3 Mounting box, 4 Support leg, 5 Mounting cylinder, 6 Mounting ring, 7 Fixing rod, 8 First annular pipe, 9 Air jet pipe, 10 First connecting pipe, 11 First fan, 12 Suction pipe, 13 Second annular pipe, 14 Water spray pipe, 15 Second connecting pipe, 16 Water pump, 17 Third annular pipe, 18 Drying pipe, 19 Third connecting pipe, 20 Second fan, 21 Gear ring, 22 Swinging gear plate, 23 Device plate, 24 Rotary shaft, 25 Slide groove, 26 Motor, 27 Turntable, 28 Slide rod, 29 Water collection hopper, 30 Return water pipe. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] A high-resilience sealing strip material for washing machines comprises the following raw materials in parts by weight: EPDM raw rubber: 100 parts; Semi-reinforcing carbon black: 10-40 parts; Quickly press out carbon black: 10-40 parts; Modified organic elastic material: 5-30 parts; Organosilane coupling agent: 0.5-3 parts; Vulcanizing agent: 0.5-3 parts; Vulcanization accelerator: 0.5-5 parts; Surfactant: 1-10 parts; Plasticizer: 5-30 parts; Anti-aging agent: 0.5-3 parts; Filler: 0-30 parts.

[0022] As a further improvement of the present invention, the EPDM raw rubber satisfies the following: Mooney viscosity ML(1+4) ≥ 60 at 125℃; The third monomer is ethylene norbornene (ENB), with a mass percentage of ≥5%; The ethylene content is 50%-60% by mass.

[0023] As a further improvement of the present invention, the modified organic elastic material is one or more modified products selected from acrylate rubber (ACM), nitrile rubber (NBR), chloroprene rubber (CR), hydrogenated nitrile rubber (HNBR), thermoplastic elastomer (TPE) or polyurethane elastomer (TPU).

[0024] As a further improvement of the present invention, the general formula of the organosilane coupling agent is R–Si(OR')3, wherein R is an organic functional group containing amino, epoxy, mercapto or vinyl groups, and R' is a C1-C4 alkyl group.

[0025] A method for preparing a sealing strip material, using a sealing strip material preparation apparatus, includes the following steps: Step 1: Weigh out each ingredient according to the recipe; Step 2: Mix the raw materials from Step 1 at 80-120℃ to obtain the compounded rubber. Step 3: Extrude the compound obtained in Step 2 at 150-220℃ and simultaneously vulcanize it to obtain the sealing strip blank; Step four: Cool and shape the sealing strip blank and output it.

[0026] See Figures 1-4The sealing strip material preparation device includes a mixer 1 and an extrusion vulcanizing machine 2. The mixer 1 is used to mix the raw materials, and the extrusion vulcanizing machine 2 is used to extrude the mixed rubber and simultaneously vulcanize it. It also includes a mounting box 3 located at the output end of the extrusion vulcanizing machine 2. Support legs 4 are fixed at the four corners of the bottom of the mounting box 3, providing support and ensuring the stability of the mounting box 3. An mounting cylinder 5 is fixed to the upper end of the mounting box 3, providing a sealed space for cooling and drying the sealing strip blank. Three mounting rings 6 are rotatably mounted inside the mounting cylinder 5, and two fixing rods 7 are fixed between the three mounting rings 6. The fixing rods 7 hold the three mounting rings 6... The components are connected as a whole to achieve synchronous rotation. Three mounting rings 6 are respectively equipped with a pre-cooling mechanism, a cooling mechanism, and a drying mechanism. The pre-cooling mechanism is closer to the extrusion vulcanizing machine 2 and is used for preliminary pre-cooling of the newly formed high-temperature sealing strip blank. The drying mechanism is further away from the extrusion vulcanizing machine 2 and is used for drying the cooled sealing strip blank. The pre-cooling mechanism includes a first annular pipe 8 fixed to the side wall of the mounting ring 6. Multiple evenly distributed air jet pipes 9 are connected to the side wall of the first annular pipe 8. The medium-temperature water vapor is uniformly sprayed onto the sealing strip blank. A first connecting pipe 10 is connected to the side wall of the first annular pipe 8. A first fan 11 is connected to the end of the first connecting pipe 10 away from the first annular pipe 8. An air suction pipe 12 is connected to the input end of the first fan 11. The end of the air suction pipe 12 away from the first fan 11 is connected to the middle of the upper side wall of the mounting cylinder 5. When the first fan 11 is started, the generated medium-temperature water vapor can be drawn out through the air suction pipe 12 and sprayed onto the sealing strip blank through the jet pipe 9 for pre-cooling. The medium-temperature water vapor is used for gentle cooling to avoid the adverse effects caused by the drastic cooling of the sealing strip blank.

[0027] The cooling mechanism includes a second annular pipe 13 fixed to the side wall of the mounting ring 6. Multiple evenly distributed water spray pipes 14 are connected to the side wall of the second annular pipe 13. The water spray pipes 14 are used to spray cooling water evenly onto the sealing strip blank to achieve rapid cooling and shaping. A second connecting pipe 15 is connected to the side wall of the second annular pipe 13. A water pump 16 is connected to the end of the second connecting pipe 15 away from the second annular pipe 13. The water pump 16 is connected to external cooling water and provides power for the delivery of cooling water. The cooling water is pumped into the second annular pipe 13 by the water pump 16 and sprayed onto the sealing strip blank through the water spray pipes 14 to cool and shape it. When the cooling water comes into contact with the sealing strip blank, medium-temperature water vapor is generated. The medium-temperature water vapor is drawn out through the suction pipe 12.

[0028] The drying mechanism includes a third annular pipe 17 fixed to the side wall of the mounting ring 6. The third annular pipe 17 is used to transport the drying airflow. The side wall of the third annular pipe 17 is connected to evenly distributed drying pipes 18. The drying pipes 18 are used to blow the airflow evenly onto the sealing strip blank to remove surface moisture. The side wall of the third annular pipe 17 is connected to a third connecting pipe 19. The end of the third connecting pipe 19 away from the third annular pipe 17 is connected to a second fan 20. The second fan 20 provides power for generating the drying airflow. When the second fan 20 is started, air can be blown onto the sealing strip blank through the drying pipes 18 to dry the sealing strip blank after it has been cooled by spraying water.

[0029] The mounting cylinder 5 is equipped with a swing mechanism connected to one of the mounting rings 6. The swing mechanism drives the three mounting rings 6 to swing back and forth, enhancing the pre-cooling, cooling, and drying effects. The swing mechanism includes a device plate 23 fixed to the upper side wall of the mounting cylinder 5. A rotating shaft 24 is rotatably connected to the side wall of the device plate 23. A swing toothed plate 22 is fixedly sleeved on the side wall of the rotating shaft 24. The rotating shaft 24 provides a fulcrum for the swing of the swing toothed plate 22. A gear ring 21 that meshes with the swing toothed plate 22 is fixed on the side wall of the mounting ring 6. The swing toothed plate 22 drives the gear ring 21 to rotate through the meshing transmission. A sliding groove 25 is provided through the side wall of the swing toothed plate 22. The sliding groove 25 cooperates with the sliding rod 28 to convert the circular motion of the turntable 27 into the swing of the toothed plate 22. The device plate 23 has a motor 26 mounted on its side wall above the rotating shaft 24. The output shaft of the motor 26 is fixedly connected to a turntable 27. A slide rod 28 is fixedly connected to the edge of the turntable 27. The slide rod 28 is slidably inserted into the slide groove 25. When the slide rod 28 slides in the slide groove 25, it pushes the swing tooth plate 22 to swing. By starting the motor 26, the turntable 27 can be driven to rotate. The rotation of the turntable 27 can drive the slide rod 28 to rotate. Since the slide rod 28 slides in the slide groove 25, it can drive the swing tooth plate 22 to swing back and forth around the rotating shaft 24. Since the swing tooth plate 22 meshes with the tooth ring 21, it can drive the tooth ring 21 to rotate back and forth. The tooth ring 21 can drive the three mounting rings 6 to rotate back and forth, which enhances convective heat transfer, significantly improves cooling efficiency and uniformity, and shortens the length of the equipment.

[0030] A water collection hopper 29 connected to the mounting cylinder 5 is fixed to the lower side wall of the mounting cylinder 5. A return water pipe 30 is connected to the bottom of the water collection hopper 29. The return water pipe 30 passes through the bottom of the mounting box 3. The water inside the mounting cylinder 5 can be collected through the water collection hopper 29 and discharged through the return water pipe 30.

[0031] The working principle of the sealing strip material preparation device of the present invention is as follows: the mixed rubber compound is extruded and simultaneously vulcanized by the extrusion vulcanization integrated machine 2 to obtain a high-temperature sealing strip blank. The blank then enters the installation box 3. The water pump 16 delivers cooling water to the second annular pipe 13 and sprays the cooling water evenly on the surface of the sealing strip blank by the water spray pipe 14 to achieve rapid cooling and shaping. The medium-temperature water vapor formed after the cooling water comes into contact with the high-temperature blank is also drawn out by the first fan 11 through the suction pipe 12. After the first fan 11 is started, the medium-temperature water vapor in the upper part of the mounting cylinder 5 is drawn in through the suction pipe 12 and sprayed out through the jet pipe 9 through the first connecting pipe 10 and the first annular pipe 8 to gently cool the sealing strip blank. The drying airflow generated by the second fan 20 is evenly blown onto the cooled sealing strip blank through the third connecting pipe 19 and the third annular pipe 17 via the drying pipe 18 to remove surface moisture. At the same time, after the motor 26 is started, the turntable 27 rotates, driving the slide rod 28 to slide in the slide groove 25, thereby pushing the swing tooth plate 22 to swing back and forth around the rotating shaft 24. Since the swing tooth plate 22 meshes with the tooth ring 21, it drives the tooth ring 21 and the mounting ring 6 fixed thereto to rotate back and forth, so that the jet pipe 9, water spray pipe 14 and drying pipe 18 in the pre-cooling mechanism, cooling mechanism and drying mechanism swing back and forth relative to the sealing strip blank, which enhances the convective heat transfer effect and improves cooling efficiency and uniformity. Meanwhile, the water collection hopper 29 fixed on the lower side wall of the mounting cylinder 5 collects the water that drips or splashes during the cooling process and discharges it to the outside of the mounting box 3 through the return water pipe 30 at its bottom, completing the entire cooling and drying process.

[0032] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-recovery elastic sealing strip material for a washing machine, characterized in that, Including the following parts by weight of raw materials: EPDM raw rubber: 100 parts; Semi-reinforcing carbon black: 10-40 parts; Quickly press out carbon black: 10-40 parts; Modified organic elastic material: 5-30 parts; Organosilane coupling agent: 0.5-3 parts; Vulcanizing agent: 0.5-3 parts; Vulcanization accelerator: 0.5-5 parts; Surfactant: 1-10 parts; Plasticizer: 5-30 parts; Anti-aging agent: 0.5-3 parts; Filler: 0-30 parts.

2. The high-recovery elastic sealing strip material for a washing machine according to claim 1, characterized in that, The EPDM raw rubber meets the following requirements: Mooney viscosity ML(1+4) ≥ 60 at 125℃; The third monomer is ethylene norbornene (ENB), with a mass percentage of ≥5%; The ethylene content is 50%-60% by mass.

3. The high-resilience sealing strip material for a washing machine according to claim 1, characterized in that, The modified organic elastic material is one or more modified products selected from acrylate rubber (ACM), nitrile rubber (NBR), chloroprene rubber (CR), hydrogenated nitrile rubber (HNBR), thermoplastic elastomer (TPE) or polyurethane elastomer (TPU).

4. The high-recovery elastic sealing strip material for a washing machine according to claim 1, characterized in that, The general formula of the organosilane coupling agent is R–Si(OR')3, wherein R is an organic functional group containing amino, epoxy, mercapto, or vinyl groups, and R' is a C1-C4 alkyl group.

5. A method for preparing the sealing strip material as described in any one of claims 1-4, characterized in that, Using a sealing strip material preparation device, the method includes the following steps: Step 1: Weigh out each ingredient according to the recipe; Step 2: Mix the raw materials from Step 1 at 80-120℃ to obtain the compounded rubber. Step 3: Extrude the compound obtained in Step 2 at 150-220℃ and simultaneously vulcanize it to obtain the sealing strip blank; Step four: Cool and shape the sealing strip blank and output it.

6. The method according to claim 5, wherein the sealing strip material preparation device comprises a mixer (1) and an integrated extrusion vulcanizing machine (2), characterized in that, It also includes a mounting box (3) located at the output end of the extrusion vulcanizing machine (2). The upper end of the mounting box (3) is fixed with a mounting cylinder (5). Three mounting rings (6) are rotatably mounted inside the mounting cylinder (5). Two fixing rods (7) are fixed between the three mounting rings (6). A pre-cooling mechanism, a cooling mechanism, and a drying mechanism are respectively provided on the three mounting rings (6). The pre-cooling mechanism is close to the extrusion vulcanizing machine (2), and the drying mechanism is away from the extrusion vulcanizing machine (2). The pre-cooling mechanism includes a first annular pipe (8) fixed on the side wall of the mounting ring (6). Multiple evenly distributed jet pipes (9) are connected to the side wall of the first annular pipe (8). A first connecting pipe (10) is connected to the side wall of the first annular pipe (8). A first fan (11) is connected to the end of the first connecting pipe (10) away from the first annular pipe (8). A suction pipe (12) is connected to the input end of the first fan (11). The air pipe (12) is connected to the middle of the upper side wall of the mounting cylinder (5) at one end away from the first fan (11). The cooling mechanism includes a second annular pipe (13) fixed on the side wall of the mounting ring (6). Multiple evenly distributed water spray pipes (14) are connected to the side wall of the second annular pipe (13). A second connecting pipe (15) is connected to the side wall of the second annular pipe (13). A water pump (16) is connected to the end of the second connecting pipe (15) away from the second annular pipe (13). The drying mechanism includes a third annular pipe (17) fixed on the side wall of the mounting ring (6). Evenly distributed drying pipes (18) are connected to the side wall of the third annular pipe (17). A third connecting pipe (19) is connected to the side wall of the third annular pipe (17). A second fan (20) is connected to the end of the third connecting pipe (19) away from the third annular pipe (17). The mounting cylinder (5) is provided with a swing mechanism connected to one of the mounting rings (6).

7. The method according to claim 6, characterized in that, The swing mechanism includes a device plate (23) fixed to the upper side wall of the mounting cylinder (5). A rotating shaft (24) is rotatably connected to the side wall of the device plate (23). A swing toothed plate (22) is fixedly sleeved on the side wall of the rotating shaft (24). A toothed ring (21) that meshes with the swing toothed plate (22) is fixed on the side wall of the mounting ring (6). A sliding groove (25) is provided through the side wall of the swing toothed plate (22). A motor (26) located above the rotating shaft (24) is installed on the side wall of the device plate (23). A turntable (27) is fixedly connected to the output shaft of the motor (26). A sliding rod (28) is fixedly connected to the edge of the turntable (27). The sliding rod (28) is slidably inserted into the inside of the sliding groove (25).

8. The method according to claim 6, characterized in that, The lower side wall of the mounting cylinder (5) is fixed with a water collection hopper (29) that communicates with the mounting cylinder (5). The bottom of the water collection hopper (29) is connected to a return water pipe (30), which passes through the bottom of the mounting box (3).

9. The method according to claim 6, characterized in that, The mounting box (3) is fixed with support legs (4) at the four corners of its bottom.

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