Rubber sealing element vulcanization molding process and production device thereof

Abstract

The invention belongs to the technical field of rubber sealing element production, and particularly relates to a rubber sealing element vulcanization forming process and a production device thereof, and the process comprises the steps of composite rubber material preparation, plasma surface modification, mold pretreatment, dynamic vulcanization, graded pressure relief soaking and finished product arrangement. The adhesive force of a rubber material is improved through composite mixing of a rubber base material, a nanometer demolding auxiliary agent and a medium-resistant modifier in combination with plasma surface treatment, precise vulcanization is achieved through a temperature-vulcanization degree linkage dynamic pressure adjusting system, and the internal stress of a product is optimized cooperatively through graded pressure relief and medium soaking; the corresponding production device integrates mixing, plasma treatment, dynamic vulcanization, soaking and finished product arrangement units, a temperature sensor and a rubber processing analyzer are arranged in a mold cavity, and a dynamic pressure adjusting system adopts a servo hydraulic pump to realize accurate pressure regulation and control. The problem of non-uniform vulcanization of a product in a traditional vulcanization process is solved, and the mechanical property and the medium-resistant stability of the sealing element are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of rubber seal production technology, specifically relating to a rubber seal vulcanization molding process and its production apparatus. Background Technology

[0002] Rubber seals are core components in machinery, automotive, aerospace, and other fields, and their sealing performance, media resistance, and service life directly affect the operational stability of equipment. Vulcanization molding is a key process in the production of rubber seals; however, current vulcanization molding processes and related equipment still face several technical challenges. 1. The vulcanization parameters mostly adopt fixed "temperature-pressure-time" curves, which cannot adapt to the vulcanization degree fluctuations caused by batch differences of rubber compounds. This can easily lead to local under-vulcanization or over-vulcanization problems, resulting in poor product performance consistency and difficulty in controlling dimensional accuracy.

[0003] 2. The post-curing stage only releases internal stress by simply cooling and holding pressure, without pre-treating the actual working medium environment of the seal. When the product is used in media such as oil and water, it is prone to swelling and aging, and the volume change rate usually exceeds ±5%, which limits its service life.

[0004] In view of this, the present invention proposes a vulcanization molding process for rubber seals and its production apparatus. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides a vulcanization molding process and production apparatus for rubber seals, the specific contents of which are as follows: In a first aspect, a vulcanization molding process for rubber seals is characterized by comprising the following steps: S1. Mix the rubber substrate with the nano release agent and the media resistance modifier, and then put them into a mixer to knead to obtain a composite rubber compound; The composite rubber compound is subjected to plasma surface treatment and then cut into rubber blanks that match the mold cavity. The weight of the rubber blanks is 4% to 7% heavier than that of the finished product. S2. The inner wall of the mold cavity is ultrasonically cleaned, and an environmentally friendly water-based release agent is evenly applied at a coating amount of 0.02-0.05 g / cm². The mold is then preheated to 00-120°C and kept at that temperature. The inner wall of the mold cavity is laser-engraved with micron-level textures, which are honeycomb or striped. S3. Place the rubber blank into the preheated mold cavity. After mold closing, the cavity temperature and rubber blank vulcanization degree are collected in real time by the temperature sensor built into the mold and the rubber processing analyzer. The pressure is dynamically adjusted to increase the vulcanization degree based on the temperature and vulcanization degree. Specifically, this includes: Filling stage: Maintain a preheating temperature of 100-120℃ in the mold cavity, apply an initial pressure of 2-4MPa for 8-12 minutes to make the blank fully fit the inner wall of the cavity, and at the same time slowly expel the air inside the blank and the gaps in the cavity. Crosslinking stage: When the degree of vulcanization reaches 30% to 40%, the temperature is raised to 145 to 165℃. When the increase in vulcanization rate is ≥5% / min, the pressure is increased by 0.5 to 1MPa. When the increase in vulcanization rate is ≤2% / min, the pressure is kept constant. Finally, the pressure is dynamically adjusted to 6 to 12MPa and maintained for 15 to 30 minutes. The vulcanizing agent is activated by the high temperature and high pressure environment, which promotes the transformation of rubber molecules from a linear structure to a three-dimensional network structure, thereby improving product performance. Stabilization phase: When the degree of sulfidation reaches 85% to 90%, the temperature is reduced to 120 to 130°C, and the segmented pressure relief is started synchronously at a rate of 5% to 10% / min to avoid excessive pressure and temperature difference between the inside and outside of the product due to sudden change in a single parameter, which may cause cracks or deformation. This process lasts for 10 to 15 minutes. S4. Maintain a temperature of 120-130℃, reduce the pressure inside the cavity at a rate of 0.2-0.5MPa / min to perform a first-stage depressurization to 1-2MPa, and continue for 5-8 minutes; then immerse the mold along with the seals inside the cavity in a preset medium at 80-100℃, and maintain a pressure of 1-2MPa for 10-20 minutes; then remove the mold from the medium, allow it to depressurize naturally to atmospheric pressure (second-stage depressurization), and simultaneously cool it to room temperature at a rate of 3-5℃ / min; S5. Remove the seal from the mold, blow away the residual medium on the surface with a high-pressure airflow of 0.5-0.7MPa, remove the flash by laser cutting, and perform a medium resistance test. After passing the test, put it into storage.

[0006] Furthermore, the processing gas of the plasma surface treatment device in step S1 is a mixture of argon and oxygen.

[0007] The dynamic adjustment of the sulfurization rate in step S3 is divided into a filling stage, a cross-linking stage, and a stabilization stage.

[0008] Secondly, during the filling stage, it is necessary to maintain the preheating temperature inside the mold cavity and apply initial pressure to ensure that the blank fully adheres to the inner wall of the cavity, while slowly expelling the air inside the blank and the gaps in the cavity. Meanwhile, during the crosslinking stage, when the degree of vulcanization reaches 30% to 40%, the temperature is increased, and the pressure is dynamically increased according to the rate of increase in the degree of vulcanization. The vulcanizing agent is activated through the high temperature and high pressure environment, which promotes the transformation of rubber molecules from a linear structure to a three-dimensional network structure, thereby improving product performance. Preferably, when the degree of vulcanization reaches 85% to 90%, the temperature is reduced to the preheating temperature, and the segmented pressure relief is started simultaneously to avoid excessive pressure and temperature difference between the inside and outside of the product due to a sudden change in a single parameter, which could cause cracks or deformation.

[0009] Furthermore, during the first-stage pressure relief in step S4, the pressure regulation rate needs to be reduced to slowly decrease the pressure, balance the pressure difference between the inside and outside of the product, and ensure that the pressure after the first-stage pressure relief is consistent with the preset pressure of the medium immersion.

[0010] In step S5, the medium resistance test involves immersing the finished product in a preset medium and keeping it at 120°C for 24 hours, then observing the product volume change rate.

[0011] The second aspect is a rubber seal production apparatus, characterized in that it includes a mixing unit, a plasma treatment unit, a rubber blank cutting unit, a mold pretreatment unit, a dynamic vulcanization unit, a segmented pressure relief-soaking unit, a finished product finishing unit, and a testing unit; The mixing unit includes an internal mixer and a vacuum degassing device. The internal mixer is used to mix and knead the rubber substrate with nano-release agent and media-resistant modifier, and the vacuum degassing device is used to degas the composite rubber compound. Secondly, the plasma treatment unit is used to perform surface modification treatment on the composite adhesive. It is equipped with an argon and oxygen mixed gas supply system, and the processing power (30-50W) and processing time (3-8min) can be adjusted. Meanwhile, the blank cutting unit is used to cut the plasma-treated composite rubber into blanks that match the mold cavity; Furthermore, the mold pretreatment unit includes an ultrasonic cleaning device, a mold release agent coating device, and a mold preheating component. The ultrasonic cleaning device is used to clean the inner wall of the mold cavity. The mold release agent coating device can uniformly coat the mold release agent at a preset coating amount of 0.02 to 0.05 g / cm². The mold preheating component is used to heat the mold to 100 to 120°C and keep it warm. The dynamic vulcanization unit includes a mold, a temperature detection unit, a vulcanization degree detection unit, and a dynamic pressure regulation system. The inner wall of the mold cavity is textured with micron-level textures, and a temperature sensor is built into the cavity. The vulcanization degree detection unit is a rubber processing analyzer used to monitor the vulcanization degree of the rubber blank in real time. The dynamic pressure regulation system is electrically connected to the temperature sensor and the rubber processing analyzer, and can dynamically adjust the pressure inside the cavity according to the collected temperature and vulcanization degree data. Secondly, the segmented pressure relief-soaking unit includes a pressure regulating component and a constant temperature soaking tank. The pressure regulating component is used to control the rate of the first-stage pressure relief and the second-stage pressure relief. The constant temperature soaking tank is used to contain the preset medium and maintain a constant temperature of 80-100℃ and a constant pressure of 1-2MPa. Meanwhile, the finished product finishing unit includes a high-pressure airflow purging device and a laser edge-cutting device. The high-pressure airflow purging device is used to remove residual media from the surface of the seal, and the laser edge-cutting device is used to remove burrs (edge-cutting accuracy ≤ 0.03mm). The dynamic pressure regulation system includes a servo hydraulic pump and a pressure controller, with a pressure regulation accuracy of ±0.1MPa and a response time of ≤0.3s; the temperature sensor is an infrared thermometer with a temperature detection accuracy of ±0.5℃.

[0012] The mold release agent coating device includes a liquid storage tank, a high-pressure atomizing nozzle, and a displacement adjustment mechanism. The atomization particle size of the high-pressure atomizing nozzle is 5-10 μm, and the displacement adjustment mechanism can drive the nozzle to make a spiral movement along the cavity wall. The constant temperature immersion tank is equipped with a temperature control system, a pressure control system, and a media filtration and recovery component, with a filtration accuracy of ≤5 μm.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses a temperature sensor and a rubber processing analyzer to monitor in real time and dynamically adjust pressure parameters to achieve closed-loop control of "temperature-vulcanization-pressure". This effectively addresses batch differences in rubber compounds and parameter fluctuations during the molding process, avoiding under-vulcanization and over-vulcanization, and improving product performance consistency by more than 20%.

[0014] 2. This invention pre-wets the sealing components in a simulated working medium through a medium immersion step, forming a stable pre-wetting layer. When the product is used in media such as oil and water, the volume change rate is controlled within ±3%, and the resistance to media swelling and service life are significantly improved.

[0015] 3. The segmented pressure relief process of this invention avoids defects such as cracks and deformation caused by sudden pressure changes; the micron-level texture of the mold cavity improves the flowability of the filling material and the venting effect. Combined with the pretreatment method of ultrasonic cleaning, the defect rate of products such as missing glue, bubbles, and flash is reduced by more than 30%. Attached Figure Description

[0016] Figure 1 This is a flowchart of the molding process of a rubber seal vulcanization molding process and its production device according to an embodiment of the present invention; Figure 2 This is a structural block diagram of an embodiment of a rubber seal vulcanization molding process and its production apparatus according to the present invention. Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0018] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0019] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] The vulcanization molding process of the present invention includes the following steps: Preparation and pretreatment of S1 composite rubber compound: The rubber substrate is mixed with nano-release agent and media-resistant modifier, and put into a mixer. It is then mixed at 120-150℃ for 15-20 min to obtain the composite rubber compound. The composite rubber compound is degassed by a vacuum exhaust device (vacuum degree -0.08 to -0.1MPa) to remove internal air bubbles. The composite rubber compound is then sent to a plasma treatment unit, where a mixture of argon and oxygen (volume ratio 8-10:1) is used as the treatment gas. The mixture is treated at 300-500W power for 3-5 min to improve the surface activity and adhesion of the rubber compound. Finally, the treated composite rubber compound is cut into rubber blanks that match the mold cavity using a CNC cutting device with a cutting accuracy of ±0.05mm. S2 Mold Pretreatment: Use ultrasonic cleaning equipment (frequency 40-60kHz) to clean the inner wall of the mold cavity for 10-15 minutes to remove residual adhesive and impurities; apply environmentally friendly water-based release agent evenly at a coating amount of 0.01-0.03g / cm² using a quantitative spraying equipment; heat the mold to 160-180℃ using an electric heating preheater and keep it at that temperature to ensure uniform mold temperature. S3 Dynamic Vulcanization: The rubber blank is placed into the preheated mold cavity, and the dynamic vulcanization unit is started after the mold is closed. The temperature of the cavity and the degree of vulcanization of the rubber blank are collected in real time by the temperature sensor (accuracy ±0.5℃) and the rubber processing analyzer (detection frequency 1 time / 30s). The dynamic pressure regulation system adjusts the pressure in three stages according to the collected data: Filling stage: Maintain cavity temperature at 100-120℃, apply initial pressure of 2-4MPa for 8-12 minutes to ensure the preform fully adheres to the cavity wall and removes air from inside and gaps; Crosslinking stage: When the degree of vulcanization reaches 30% to 40%, the temperature is raised to 145 to 165℃. When the increase in vulcanization rate is ≥5% / min, the pressure is increased by 0.5 to 1MPa. When the increase in vulcanization rate is ≤2% / min, the pressure is kept constant. Finally, the pressure is dynamically adjusted to 6 to 12MPa and maintained for 15 to 30 minutes. The vulcanizing agent is activated by the high temperature and high pressure environment, which promotes the transformation of rubber molecules from a linear structure to a three-dimensional network structure, thereby improving product performance. Stabilization phase: When the degree of sulfidation reaches 85% to 90%, the temperature is reduced to 120 to 130°C, and the segmented pressure relief is started synchronously at a rate of 5% to 10% / min to avoid excessive pressure and temperature difference between the inside and outside of the product due to sudden changes in a single parameter, which may cause cracks or deformation. This process lasts for 10 to 15 minutes. S4 Stage Depressurization and Medium Immersion: Perform the first stage of depressurization at a rate of 0.2–0.5 MPa / min, reducing the pressure to 1–2 MPa (consistent with the immersion medium pressure); immerse the entire mold in the preset medium (hydraulic oil, brake fluid, or aviation kerosene) in a constant temperature immersion tank for 10–20 minutes at 80–100°C and 1–2 MPa to further optimize the product's resistance to the medium; then remove the mold and perform the second stage of depressurization to atmospheric pressure at a rate of 1–2 MPa / min. S5 Finished Product Finishing and Inspection: Open the mold and remove the seal. Blow away the residual medium on the surface with a high-pressure airflow of 0.5-0.7MPa. Use a laser cutting device to remove the flash with a cutting accuracy of ±0.02mm. Immerse the finished product in the preset medium and keep it at 120℃ for 24 hours. Detect the volume change rate. Qualified products (volume change rate ≤3%) are put into storage. Rubber Seal Production Equipment: The production equipment of this invention includes a mixing unit, a plasma treatment unit, a rubber blank cutting unit, a mold pretreatment unit, a dynamic vulcanization unit, an impregnation unit, and a finished product finishing unit. These units are connected sequentially to achieve automated production. The mixing unit consists of an internal mixer and a vacuum exhaust device. The internal mixer provides a stable mixing environment, while the vacuum exhaust device ensures that the rubber compound is free of air bubbles and improves the density of the rubber compound. Plasma treatment unit: Improves the surface activity of rubber compound through plasma surface modification, enhances the adhesion to the mold and the uniformity of subsequent vulcanization reaction; Rubber blank cutting unit: CNC cutting equipment ensures that the size of the rubber blank is precisely matched with the mold cavity, reducing the amount of rubber overflow during the vulcanization process; Mold pretreatment unit: Ultrasonic cleaning ensures clean cavity, quantitative application of release agent avoids residue, and mold preheating component ensures stable initial vulcanization temperature; Dynamic vulcanization unit: Micron-level texture on the inner wall of the cavity improves the adhesion of the product surface; temperature sensor and rubber processing analyzer enable real-time parameter monitoring; servo hydraulic pump and pressure controller precisely adjust the pressure to achieve dynamic vulcanization; Immersion Unit: The constant temperature immersion tank maintains stable medium temperature and pressure, and further improves the product's resistance to media through immersion in the medium; Finished product finishing unit: High-pressure airflow effectively removes residual media, and laser edge cutting equipment precisely removes burrs, ensuring product dimensional accuracy.

[0022] Example 1: Nitrile rubber O-rings, for oil-resistant working conditions S1. Rubber compound preparation and modification: Nitrile rubber was selected as the rubber base material. 2% nano boron nitride and 3% maleic anhydride-grafted butadiene polymer were added by mass fraction. The mixture was put into a mixer and mixed for 15 minutes at 85℃ and 40 r / min to ensure uniform dispersion of the components and obtain a composite rubber compound. The composite rubber compound was then sent to a vacuum degassing device and degassed for 6 minutes at a vacuum of -0.085 MPa to remove air bubbles and volatiles from the rubber compound. Subsequently, the degassed composite rubber compound was placed in a plasma treatment device, and a mixture of argon and oxygen (mixing volume ratio 9:1) was introduced. The treatment power was adjusted to 40W, the treatment distance to 8mm, and the treatment time to 5 minutes to complete the surface modification of the rubber compound. Finally, the rubber blank was cut by the blank cutting unit according to the size and volume of the O-ring mold cavity to obtain a blank weighing 5% heavier than the finished product, ensuring that there is no missing rubber after molding.

[0023] S2. Mold Pre-treatment: A precision mold compatible with the O-ring is selected. The inner wall of the mold cavity is laser-engraved with a honeycomb micron-level texture with a depth of 10μm and a spacing of 80μm. First, the inner wall of the mold cavity is cleaned for 10 minutes using an ultrasonic cleaning device to remove oil, impurities, and residual adhesive. After cleaning, the mold release agent coating device is activated, and environmentally friendly polyether modified silicone oil water-based mold release agent (viscosity 45mPa・s) is evenly coated onto the inner wall of the cavity at a coating amount of 0.03g / cm². Then, the mold is placed in the mold preheating assembly, heated to 110℃ and held at that temperature for 30 minutes to ensure a uniform and stable cavity temperature and avoid local temperature differences affecting the vulcanization effect of the adhesive.

[0024] S3. Dynamic vulcanization molding: The cut rubber blank is smoothly placed into the preheated mold cavity, and the vulcanizing machine is started and the mold is closed. After the mold is closed, the temperature sensor built into the mold collects the cavity temperature in real time, and the rubber processing analyzer monitors the vulcanization degree of the rubber blank at a frequency of 1 time / min. The dynamic pressure regulation system dynamically adjusts the pressure in the cavity to increase the vulcanization rate based on the collected temperature and vulcanization degree data, which is specifically divided into three stages: Filling stage: Maintain cavity temperature at 110℃ (consistent with mold preheating temperature), apply initial pressure of 3MPa for 10 minutes, so that the preform can flow fully in a low pressure and medium-low temperature environment, closely adhere to the inner wall of the cavity and micron-level texture, and at the same time slowly expel air from the inside of the preform and the gaps in the cavity to avoid defects such as bubbles and missing glue after molding. Crosslinking stage: When the rubber processing analyzer detects that the vulcanization degree of the rubber blank reaches 35%, the temperature of the cavity is raised to 155℃ through the temperature control system of the vulcanizing machine; the pressure is dynamically adjusted according to the vulcanization degree increase rate: when the vulcanization degree increase rate is ≥5% / min, the pressure is increased by 0.8MPa each time; when the vulcanization degree increase rate is ≤2% / min, the pressure is kept constant, and the final pressure is stabilized at 9MPa. This stage lasts for 22 minutes. The high temperature and high pressure environment activates the vulcanizing agent in the rubber compound, causing the nitrile rubber molecules to transform from a linear structure to a three-dimensional network structure, which significantly improves the elasticity, strength and media resistance of the product. Stabilization phase: When the degree of vulcanization reaches 88%, the cavity temperature is reduced to 110℃ (preheating temperature), and the segmented pressure relief is started simultaneously. The pressure is gradually reduced from 9MPa to 4MPa at a rate of 8% / min for 12 minutes to avoid excessive pressure and temperature difference between the inside and outside of the product due to a sudden change in a single parameter, which may cause cracks or deformation.

[0025] S4. Staged pressure relief and medium immersion: First-stage pressure relief: After the stabilization phase, maintain the cavity temperature at 110℃, and slowly depressurize to 1.5MPa at a rate of 0.3MPa / min through the pressure regulation system for 6 minutes to balance the pressure difference between the inside and outside of the product and prepare for subsequent medium immersion. Medium immersion: The mold in the closed state is steadily lifted into the constant temperature immersion tank. The immersion tank is pre-injected with mineral oil at 100℃. This mineral oil is the same as the actual working medium of the O-ring. The pressure control system of the immersion tank is started to maintain the pressure in the tank at 1.5MPa, which is the same as the pressure after the first stage of pressure relief. Immersion for 15 minutes allows the mineral oil to penetrate to the surface of the O-ring under pressure and form a stable pre-wetting layer. Secondary depressurization: After soaking, the mold is lifted out of the soaking tank by a hoist, the mineral oil adhering to the surface is drained, and it is placed in the cooling station to naturally depressurize to atmospheric pressure. At the same time, it is gradually cooled to room temperature at a rate of 4℃ / min to further release the residual stress inside the product.

[0026] S5. Finished Product Finishing and Inspection: After the mold cools to room temperature, open the mold and remove the O-ring; start the high-pressure airflow purging device to blow the surface of the O-ring with an airflow pressure of 0.6MPa to remove residual mineral oil; then remove the flash from the product edges using a laser edge cutting device; place the finished product into the testing equipment, immerse it in mineral oil and keep it at 120℃ for 24 hours, observe and measure the volume change rate of the product, and a volume change rate ≤±3% is considered a qualified product. After passing the test, the product is put into storage for future use.

[0027] Example 2: Fluororubber sealing gasket, resistant to high-temperature working conditions S1. Rubber compound preparation and modification: Fluororubber was selected as the rubber base material. 3% nano-silica release agent and 5% vinyltriethoxysilane media-resistant modifier were added by mass fraction. The mixture was put into a mixer and mixed for 20 minutes at 95℃ and 35 r / min to obtain a composite rubber compound. After degassing by a vacuum exhaust device, the composite rubber compound was sent to a plasma treatment device. A mixture of argon and oxygen (volume ratio 10:1) was introduced, with a treatment power of 50W and a treatment time of 8 minutes. Finally, a rubber blank weighing 7% heavier than the finished product was obtained by cutting.

[0028] S2. Mold pretreatment: Place the plastic blank into the mold, ultrasonically clean it for 12 minutes, and then apply an environmentally friendly water-based release agent at a coating amount of 0.05 g / cm²; preheat the mold to 120°C and keep it at that temperature for 40 minutes.

[0029] S3. Dynamic vulcanization molding: Filling stage: Maintain 120℃, apply an initial pressure of 2MPa, and continue for 12 minutes; Crosslinking stage: When the degree of vulcanization reaches 40%, the temperature is raised to 165℃, the pressure is dynamically adjusted to 12MPa, and the process is continued for 30 minutes. Stabilization phase: When the degree of sulfidation reaches 90%, cool down to 120℃ and depressurize to 5MPa at a rate of 10% / min for 15min.

[0030] S4. Staged pressure relief and medium immersion: First-stage pressure relief: Depressurize to 2MPa at a rate of 0.5MPa / min at 120℃ for 8 minutes; Medium immersion: Immerse the mold in silicone oil at 100℃ and maintain a pressure of 2MPa for 20 minutes; Secondary depressurization: Remove the mold and allow it to depressurize naturally to atmospheric pressure, then cool it to room temperature at a rate of 5℃ / min.

[0031] S5. Finished Product Finishing and Inspection: The surface residual silicone oil is blown away with a high-pressure airflow of 0.7MPa, and the flash is removed by laser cutting; the finished product is immersed in silicone oil and kept at 120℃ for 24 hours. The volume change is observed. The product is qualified if there is no obvious cracking or swelling abnormality and the volume change rate is ≤±3%.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rubber seal vulcanization molding process characterized by, The method comprises the following steps: S1. Mixing the rubber base material with nano-release aids and medium-resistant modifiers, and feeding into a mixer to obtain a compound; The compound is subjected to plasma surface treatment, and then cut into a rubber blank matching the mold cavity; S2. Ultrasonic cleaning the inner wall of the mold cavity, uniformly coating with an environmentally friendly water-based release agent, and then preheating; S3. Placing the rubber blank into the preheated mold cavity, closing the mold, and collecting the cavity temperature and rubber blank curing degree in real time according to the temperature sensor and rubber processing analyzer built in the mold, and dynamically adjusting the curing degree of the pressure according to the temperature and curing degree; S4. Reducing the pressure in the cavity for primary pressure relief, and then immersing the mold in a pre-set medium for a period of time; Then the mold is taken out of the medium, and secondary pressure relief is performed; S5. Taking the sealing element out of the mold, blowing the surface residual medium through a high-pressure gas flow, laser trimming to remove burrs, and detecting the medium-resistant performance.

2. The rubber sealing element vulcanization forming process according to claim 1, wherein: The treatment gas of the plasma surface treatment equipment in step S1 is a mixed gas of argon and oxygen.

3. The rubber sealing element vulcanization forming process according to claim 1, wherein: The curing degree dynamic adjustment in step S3 is divided into a filling stage, a crosslinking stage, and a stable stage.

4. The rubber sealing element vulcanization forming process according to claim 3, wherein: In the filling stage, the temperature in the mold cavity is maintained at 100-120℃, an initial pressure of 2-4MPa is applied, the rubber blank is fully attached to the inner wall of the cavity, and the air in the rubber blank and the gap of the cavity is slowly discharged; In the crosslinking stage, when the curing degree reaches 30%-40%, the temperature is raised to 145-165℃, the pressure is dynamically increased to 6-12MPa according to the curing degree, the vulcanizing agent is activated in a high-temperature and high-pressure environment, the rubber molecules are converted from a linear structure to a three-dimensional network structure, and the product performance is improved; In the stable stage, when the curing degree reaches 85%-90%, the temperature is reduced to 120-130℃, and the segmented pressure relief is started synchronously to avoid a large difference in product internal and external pressure and temperature caused by a single parameter mutation, which may cause cracks or deformation.

5. The rubber sealing element vulcanization forming process according to claim 1, wherein: In step S4, when the primary pressure relief is performed, the pressure adjustment rate needs to be reduced, the pressure is slowly reduced, the internal and external pressure difference of the product is balanced, and the pressure after the primary pressure relief is consistent with the pre-set pressure of the medium immersion.

6. The rubber sealing element vulcanization forming process according to claim 1, wherein: In step S5, the medium-resistant performance detection is to immerse the finished product in a pre-set medium at 120℃ for 24h, and observe the volume change rate of the product.

7. A rubber sealing element production device, comprising a mixing unit, a plasma treatment unit, a rubber blank cutting unit, a mold pretreatment unit, a dynamic vulcanization unit, an immersion unit, and a finished product finishing unit. ​ The mixing unit comprises a banbury mixer and a vacuum exhaust device, the banbury mixer is used for mixing and compounding the rubber base material with the nano release agent and the medium-resistant modifier, and the vacuum exhaust device is used for degassing treatment of the composite rubber material; The plasma treatment unit is used for surface modification treatment of the composite rubber material; The rubber blank cutting unit is used for cutting the composite rubber material after plasma treatment into rubber blanks matched with the mold cavity; The mold pretreatment unit comprises an ultrasonic cleaning device, a release agent coating device and a mold preheating assembly, the ultrasonic cleaning device is used for cleaning the inner wall of the mold cavity, the release agent coating device can uniformly coat the release agent according to the preset coating amount, and the mold preheating assembly is used for heating the mold to a preset temperature and maintaining the temperature; The dynamic vulcanization unit comprises a mold, a temperature detection unit, a vulcanization degree detection unit and a dynamic pressure adjusting system, the inner wall of the cavity of the mold is provided with micron-level texture, and a temperature sensor is arranged in the cavity, the vulcanization degree detection unit is a rubber processing analyzer, and is used for real-time monitoring of the vulcanization degree of the rubber blank; and the dynamic pressure adjusting system comprises a servo hydraulic pump and a pressure controller; The soaking unit comprises a constant-temperature soaking tank, which is used for accommodating a preset medium and maintaining constant temperature and pressure; The finished product finishing unit comprises a high-pressure gas flow blowing device and a laser trimming device, the high-pressure gas flow blowing device is used for removing residual medium on the surface of the sealing element, and the laser trimming device is used for removing the flash. The soaking unit comprises a constant-temperature soaking tank, which is used for accommodating a preset medium and maintaining constant temperature and pressure; The finished product finishing unit comprises a high-pressure gas flow blowing device and a laser trimming device, the high-pressure gas flow blowing device is used for removing residual medium on the surface of the sealing element, and the laser trimming device is used for removing the flash.

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