Negative pressure purification method and negative pressure purification system

Abstract

The invention relates to a negative pressure purification method and a negative pressure purification system. In at least one of the heating process, the air exhaust process and the pressure relief process, the temperature in the extraction box is controlled to be changed to the extraction temperature required by the extraction process according to a temperature rise curve represented by a temperature model, the temperature model is represented as follows: a is the temperature rise slope, t0 is the duration required by heating to half of the extraction temperature, and t0 is the duration required by heating to half of the extraction temperature; t is any moment, f (t) represents the temperature rise increment proportion at the moment t, the temperature rise increment proportion represents the proportion of the current heated amount in the total temperature rise amount, the current heated amount is equal to the difference between the current temperature and the initial temperature, and the total temperature rise amount is equal to the difference between the extraction temperature and the initial temperature. Therefore, the smooth and continuous change of the temperature can realize a better process window, compared with a solvent extraction method, more extraction time is saved, and the purification effect equivalent to that of the solvent extraction method is achieved. And meanwhile, overshoot during PID adjustment can be reduced, and a rapid and stable temperature set value is achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of negative pressure purification, and in particular to a negative pressure purification method and a negative pressure purification system. Background Art

[0002] Polymer materials are widely used in coatings, adhesives, and medical applications. They are primarily obtained through monomer polymerization. Since monomer conversion during polymerization rarely reaches 100%, some unreacted monomers, typically 0.2-5%, remain in the material. This can cause unpleasant odors and reduce some biological, chemical, and physical performance indicators. Volatility of residual monomers during product use can cause environmental pollution and pose biotoxicity concerns in medical applications. Therefore, in most cases, polymer materials require the removal of residual monomers before use. Common removal methods include solvent extraction and constant temperature negative pressure extraction.

[0003] Solvent extraction involves immersing the material to be extracted in an organic solvent that is miscible with the residual monomers in the material. After a period of time, the material is dried in an oven. While this method offers the advantage of a more thorough extraction process, its disadvantages include a complex and lengthy extraction cycle, requiring the selection of a suitable solvent and consisting of two steps: extraction and drying. Furthermore, it can cause subtle damage to the material surface, potentially affecting the optical properties of the material (particularly IOLs).

[0004] In order to reduce the impact on the surface or optical properties of the material, vacuum extraction can be used for removal.

[0005] The vacuum extraction method involves spreading the material to be extracted into a vacuum drying oven and then periodically replacing the air inside to ensure that the volatilized monomers are effectively extracted from the drying oven. The advantage of vacuum extraction is that it does not directly contact the material surface, thus having no effect on the appearance or optical properties of the material (especially intraocular lenses). However, the disadvantage of vacuum extraction is that the extraction effect is dependent on the temperature inside the chamber, the frequency of extraction ventilation, and the extraction cycle.

[0006] Temperature control in existing vacuum extraction solutions typically uses a step-type temperature control setpoint, which often results in overshoot and repeated oscillations during temperature changes. The temperature control model is a high-inertia hysteresis system, making it impossible to achieve accurate temperature control using traditional PID control algorithms. Processes like vacuuming and pressure relief introduce significant temperature fluctuations, making temperature control accuracy unreliable. Furthermore, existing vacuum extraction solutions require multiple manual operations to replace air, consuming significant human resources, reducing production efficiency, and preventing process consistency.

[0007] Therefore, it is necessary to provide a new negative pressure purification solution to solve at least one of the above problems existing in the existing solution. Summary of the Invention

[0008] A technical problem to be solved by the present disclosure is how to accurately and smoothly control the temperature during the negative pressure purification process.

[0009] According to a first aspect of the present disclosure, a negative pressure purification system is provided, comprising: a plurality of extraction boxes; a heating module, a temperature sensor, a temperature transmitter, and a temperature controller associated with each of the extraction boxes, wherein the temperature sensor and the heating module are arranged in a cavity of the extraction box, the temperature sensor sends a detected temperature signal to the temperature transmitter, the temperature transmitter converts the temperature signal into a standard signal and sends the signal to the temperature controller, and during at least one of a heating process, an exhaust process, and a pressure relief process, the temperature controller controls the working state of the heating module based on the standard signal so that the temperature in the cavity changes to the extraction temperature required for the extraction process according to a temperature rise curve represented by a temperature model.

[0010] The temperature model is expressed as

[0011] Wherein, a is the temperature rise slope, t0 is the time required to heat to half the extraction temperature, t is any time, f(t) represents the incremental ratio of temperature rise at time t, and the incremental ratio of temperature rise represents the ratio of the current temperature rise to the total temperature rise. The current temperature rise is equal to the current temperature minus the initial temperature, and the total temperature rise is equal to the extraction temperature minus the initial temperature.

[0012] Optionally, the negative pressure purification system also includes a vacuum negative pressure pump, the air suction hole of the vacuum negative pressure pump is connected to each of the extraction boxes through a pipe, and a vacuum negative pressure pump air inlet valve and an extraction box air suction valve are arranged in the pipe connecting the air suction hole of the vacuum negative pressure pump and the extraction box. The vacuum negative pressure pump air inlet valve is arranged close to the vacuum negative pressure pump, and the extraction box air suction valve is arranged close to the extraction box. The exhaust hole of the vacuum negative pressure pump is connected to the ventilation system through a pipe, and a vacuum negative pressure pump outlet valve is arranged in the pipe connecting the exhaust hole of the vacuum negative pressure pump and the ventilation system.

[0013] Optionally, the extraction box is also connected to the atmosphere through a pipeline, and an air intake precision regulating valve is also provided in the pipeline connecting the extraction box and the atmosphere.

[0014] Optionally, the vacuum negative pressure pump is connected in parallel with the plurality of extraction boxes through a plurality of pipelines, and the air intake precision regulating valve and the extraction box air extraction valve belonging to the same extraction box are in a series structure.

[0015] Optionally, during the vacuuming process, the extraction box extraction valve, the vacuum negative pressure pump inlet valve, and the vacuum negative pressure pump outlet valve are all set to the open state, and the air intake precision regulating valve is set to the closed state; during the pressure relief process, the extraction box extraction valve and the air intake precision regulating valve are set to the open state, and the vacuum negative pressure pump inlet valve is set to the closed state.

[0016] Optionally, the negative pressure purification system also includes: an automatic control system, the automatic control system includes a circuit board, the circuit board is configured with a chip, input / output channels, and a power management module, the input / output channels are respectively connected to the vacuum negative pressure pump inlet valve, the vacuum negative pressure pump outlet valve, the extraction box exhaust valve, and the air intake precision regulating valve, the power management module is used to provide power management functions for the vacuum negative pressure pump, the extraction box, the vacuum negative pressure pump inlet valve, the vacuum negative pressure pump outlet valve, the extraction box exhaust valve, and the air intake precision regulating valve, and the chip is configured to perform a vacuuming process and a pressure relief process for the extraction box at predetermined intervals according to a program.

[0017] Optionally, the circuit board is further configured with at least one of a network card, a display interface, and a USB interface.

[0018] Optionally, the value of t0 is set based on the system's comprehensive resistance to the heating rate, and the value of t0 is positively correlated with the comprehensive resistance.

[0019] Optionally, the value of t0 is positively correlated with the heat capacity of the extraction box and its internal structure; and / or the value of t0 is negatively correlated with the maximum available power of the heating module; and / or the value of t0 is positively correlated with the total mass of the material that needs to be negatively pressure purified in the extraction box; and / or the value of t0 is positively correlated with the specific heat capacity of the material that needs to be negatively pressure purified in the extraction box; and / or the value of t0 is positively correlated with the effective heat loss coefficient of the system; and / or the value of t0 is positively correlated with the process's requirement for temperature rise mildness; and / or the value of t0 is positively correlated with the degree of vacuum.

[0020] Optionally, the value of a during the air extraction process and / or the pressure relief process is lower than the first value.

[0021] Optionally, the negative pressure purification system is used to perform negative pressure purification on intraocular lens materials.

[0022] According to a second aspect of the present disclosure, a negative pressure purification method is provided, comprising: controlling the temperature in an extraction box to a desired extraction temperature according to a temperature rise curve represented by a temperature model during at least one of a temperature increase process, a gas extraction process, and a pressure relief process;

[0023] The temperature model is expressed as

[0024] Wherein, a is the temperature rise slope, t0 is the time required to heat to half the extraction temperature, t is any time, f(t) represents the incremental ratio of temperature rise at time t, and the incremental ratio of temperature rise represents the ratio of the current temperature rise to the total temperature rise. The current temperature rise is equal to the current temperature minus the initial temperature, and the total temperature rise is equal to the extraction temperature minus the initial temperature.

[0025] Optionally, the method is used to perform negative pressure purification on artificial lens materials, and the extraction temperature is 40°C to 90°C; and / or the extraction time is 5 minutes to 30 minutes; and / or the extraction time is 3 days to 9 days; and / or an extraction cycle is performed every 2 hours to 8 hours; each extraction cycle includes a extraction process and a pressure relief process.

[0026] Optionally, after the extraction process is completed, the method further includes: placing the intraocular lens material in the extraction box into a dryer for natural cooling, weighing the cooled intraocular lens material, and calculating the change in the material residual rate based on the weight before extraction; and / or milling the intraocular lens material, and testing the tensile strength using a loop tensile strength testing machine; and / or testing the modulation transfer function of the intraocular lens material using an intraocular lens optical measuring instrument.

[0027] Optionally, the method further includes: setting a value of t0 based on the system's comprehensive resistance to the heating rate, and the value of t0 is positively correlated with the comprehensive resistance.

[0028] Optionally, the value of t0 is positively correlated with the heat capacity of the extraction box and its internal structure; and / or the value of t0 is negatively correlated with the maximum available power of the heating module; and / or the value of t0 is positively correlated with the total mass of the material that needs to be negatively pressure purified in the extraction box; and / or the value of t0 is positively correlated with the specific heat capacity of the material that needs to be negatively pressure purified in the extraction box; and / or the value of t0 is positively correlated with the effective heat loss coefficient of the system; and / or the value of t0 is positively correlated with the process's requirement for temperature rise mildness; and / or the value of t0 is positively correlated with the degree of vacuum.

[0029] Optionally, the value of a during the air extraction process and / or the pressure relief process is lower than the first value.

[0030] Therefore, during the heating process, vacuuming / depressurization cycles, and other processes, the present disclosure uses a continuous and smooth temperature model for temperature control, transforming the temperature setpoint into a smooth, continuous curve. This smooth, continuous temperature change enables a wider process window, saving extraction time compared to solvent extraction, while achieving comparable purification results. Furthermore, it reduces overshoot during PID adjustment, achieving a fast and stable temperature setpoint. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, wherein like reference numerals generally represent like components in the exemplary embodiments of the present disclosure.

[0032] Figure 1 A schematic diagram of the step response curve of the traditional PID control algorithm is shown.

[0033] Figures 2A to 2C A schematic diagram of the temperature rise curve is shown for different values ​​of a and t0 in the temperature model.

[0034] Figure 3 A schematic structural diagram of a negative pressure purification system of a single-channel extraction device according to an embodiment of the present disclosure is shown.

[0035] Figure 4 A schematic structural diagram of a negative pressure purification system of a multi-channel extraction device according to an embodiment of the present disclosure is shown.

[0036] Figure 5 A schematic structural diagram of a single-chip microcomputer circuit board according to an embodiment of the present disclosure is shown.

[0037] Figure 6 A schematic diagram of the startup procedure for one cycle of the extraction box is shown.

[0038] 7A to 7E Schematic diagrams of specific performance data of comparative examples and embodiments are shown. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0040] The following describes the negative pressure purification scheme of the present disclosure using the negative pressure purification of intraocular materials as an example. It should be understood that the negative pressure purification scheme of the present disclosure can also be used to perform negative pressure purification on other types of polymeric materials. Furthermore, when performing negative pressure purification on other types of polymeric materials, the process parameters employed (e.g., extraction temperature, extraction time, extraction interval, pumping time, etc.) may differ from those employed for negative pressure purification of intraocular materials.

[0041] With the continuous development of ophthalmic medical technology, the first generation of non-foldable intraocular lenses have been eliminated, and now the mainstream intraocular lenses are all foldable intraocular lenses. Foldable intraocular lenses have the advantages of small size, easy operation, and fast postoperative recovery. Stackable intraocular lenses are made by removing the natural lens and using special materials to make small foldable pieces, which are unfolded and implanted into the eye during surgery. Due to its small size, it can more easily enter the inside of the eyeball through a tiny incision, thereby reducing damage to surrounding tissues. Therefore, the intraocular material in the present disclosure may refer to a foldable intraocular lens material.

[0042] Hydrophobic or hydrophilic acrylates are currently the most commonly used materials for foldable intraocular lenses. During the production process, unreacted monomers are often present in the synthesized material, necessitating extraction to minimize residual residues. This low residual residue is a key factor in the material's high safety and stability, ensuring the material's low toxicity and long-term safety for cataract patients after implantation.

[0043] A common method is extraction using organic solvents. This not only introduces the risk of contamination of new raw materials, but can also damage the properties of the original materials, affecting optical imaging quality. Common, unreacted acrylic monomers can be extracted using organic solvents such as nitriles, alkanes, lipids, and alcohols. However, this purification process can affect the optical properties of intraocular materials to varying degrees. Therefore, negative pressure purification technology is used to prevent the intraocular material from coming into contact with organic solvents while still effectively and significantly reducing the residual rate of unreacted monomers.

[0044] The negative pressure purification process requires the use of a dedicated negative pressure extraction device. When negative pressure is established within the device's chamber, the number of gas molecules per unit volume is significantly reduced, the molecular mean free path is increased, and collisions between gas molecules and between gas particles are reduced, significantly lowering the boiling point of the monomer material. For example, the boiling point of acrylic acid monomers can be significantly lowered under negative pressure compared to standard atmospheric pressure. The combination of low negative pressure and high temperature can volatilize residual liquid monomers into a gaseous state and separate them from the material.

[0045] The temperature control commonly used in existing negative pressure purification processes is based on step-type temperature control setpoints, which often experience overshoot and repeated oscillations during temperature changes. The temperature control model is a high-inertia hysteresis system, making it impossible to achieve accurate temperature control using traditional PID control algorithms. Processes such as pumping and pressure relief introduce significant temperature fluctuations, making temperature control accuracy unreliable. Figure 1 Figure 2 shows a schematic diagram of the step response curve of the traditional PID control algorithm. Figure 1As shown, the traditional temperature control Ym will exceed the set value (for example, more than 2-5 ° C), and the adjustment time Ts is long, up to tens of minutes. This step-type temperature setting value will bring great challenges to the control of the negative pressure purification process.

[0046] To address this, the present disclosure proposes a continuous smoothing temperature model:

[0047]

[0048] Where a is the temperature rise slope, t0 is the time required to reach half the extraction temperature, t is any time, and f(t) represents the incremental temperature rise ratio at time t. The incremental temperature rise ratio represents the proportion of the current temperature rise to the total temperature rise. The current temperature rise is equal to the current temperature minus the initial temperature, and the total temperature rise is equal to the extraction temperature minus the initial temperature. The value range of f(t) is (0, 1).

[0049] f(t) can also be called the temperature rise process factor, which represents the degree of completion from the initial state (i.e., initial temperature) to the target state (i.e., extraction temperature). The above temperature model can also be expressed as,

[0050]

[0051] Where T(t) represents the cavity set temperature at time t, which is the target value that the temperature controller strives to achieve; T initial represents the initial temperature; T target Indicates the extraction temperature; ΔT total Indicates the total amount of temperature rise that needs to be completed.

[0052] In this disclosure, t0 can be considered half the heating time, and 2×t0 can be considered the heating time. That is, when t = 2×t0, the current temperature is considered to have reached the set temperature. Furthermore, a simple parameter tuning strategy can be used to set a×t0 to a fixed value (e.g., 12) to accommodate varying heating times while maintaining a consistent heating rate threshold.

[0053] The following is a further explanation of some details involved in the temperature model.

[0054] As mentioned above, t0 is numerically equivalent to half the heating time. That is, the value of t0 can represent the length of the heating time. When setting t0, you can refer to the system's comprehensive resistance to the heating rate to ensure that the set t0 value matches the system's comprehensive resistance to the heating rate. The system's comprehensive resistance to the heating rate reflects the system's comprehensive demand for the heating rate. The system's comprehensive resistance to the heating rate depends on a variety of factors (for example, see the following description). Therefore, the value of t0 can be set by comprehensively considering the resistance of various factors to the heating rate.

[0055] For example, the value of t0 can be set based on the following factors. It should be understood that the factors described below include not only factors related to the thermal inertia of the system (heat capacity, thermal conductivity, etc.), but also other factors that can characterize the system's resistance to or demand for the heating rate (such as Factor 2 and Factor 5 described below).

[0056] Factor 1: The heat capacity of the extraction chamber and its internal structure. Heat capacity has a positive effect on the heating rate. The greater the heat capacity, the slower the heating rate, and t0 needs to be increased accordingly. Factor 2: The maximum available power of the heating module. The maximum available power of the heating module has a negative effect on the heating rate. The greater the maximum available power of the heating module, the greater the potential heating capacity, and t0 can be reduced accordingly. Factor 3: The total mass and specific heat capacity of the materials (such as intraocular lens materials) to be purified under negative pressure within the extraction chamber. The total mass and specific heat capacity of the polymer material have a positive effect on the heating rate. The heat absorbed by the polymer material is positively correlated with the total mass and specific heat capacity, respectively. At a given power, the greater the total mass and specific heat capacity, the longer the heating time, and the corresponding t0 needs to be increased. Factor 4: The effective heat loss coefficient of the system. The effective heat loss coefficient of the system has a positive effect on the heating rate. In a vacuum environment, heat loss is mainly through radiation and conduction. The greater the heat loss, the lower the power available for heating, and the corresponding t0 needs to be increased. Factor 5: The process's requirements for gentle temperature rise have a positive impact on the resistance to the heating rate. The higher the process's requirements for gentle temperature rise, the slower the heating needs to be, and t0 needs to be increased accordingly. For example, for certain heat-sensitive artificial crystal materials, slow heating is required to avoid thermal stress or degradation, so t0 needs to be increased. Factor 6: The influence of vacuum degree: The vacuum degree has a positive impact on the resistance to the heating rate. At low pressure, gas convection heat transfer almost disappears, relying primarily on heat conduction and radiation. This typically reduces the overall heat transfer efficiency of the system, causing the temperature to rise more slowly than at normal pressure at the same heating power. Therefore, t0 needs to be increased to accommodate the heat transfer characteristics of a vacuum environment.

[0057] In some embodiments, the value of t0 is the result of a comprehensive consideration of factors such as equipment specifications (heat capacity, power, etc.), material properties (mass, specific heat capacity, thermal sensitivity, etc.), and vacuum environment characteristics. For example, for materials with high heat capacity or high thermal sensitivity, a larger t0, such as 600s to 1200s, can be selected; for small-batch, heat-resistant materials, a smaller t0, such as 300s to 600s, can be selected.

[0058] The temperature rise slope, a, can also be called the curve shape factor or the rise rate coefficient. a controls the steepness of the transition of f(t) from slow change to fast change and then back to slow change near t0. The larger the value of a, the steeper the transition of the curve near t0, and the faster the temperature rise process in the intermediate stage, which is closer to a step change (but still continuous without overshoot). This is suitable for scenarios where the temperature rise rate is required to be high and the material is relatively resistant to thermal shock. The smaller the value of a, the smoother the transition of the curve near t0, and the more uniform and gentle the change of the entire temperature rise process. This is extremely critical for negative pressure purification processes, especially when dealing with vacuum and pressure relief disturbances.

[0059] When vacuuming, the pressure in the cavity drops sharply, and the number of gas molecules decreases, resulting in a sharp drop in heat conduction capacity (vacuum insulation effect), which significantly reduces the effective thermal conductivity of the system. If the temperature setpoint is in a rapid rise or step state at this time, the actual temperature will drop significantly because the heat input cannot keep up with the loss (or the response is delayed). A small value of a means that even near t0, the rate of change of the temperature setpoint is relatively low and stable. This makes it easier for the temperature controller to track this slowly changing setpoint when a vacuum disturbance occurs, greatly suppressing the actual temperature drop and fluctuation time.

[0060] Similarly, during pressure relief (air filling), the cavity pressure increases and the gas's heat transfer capacity recovers. If the setpoint changes too quickly at this time, it can easily cause the actual temperature to overshoot. A gradual setpoint change can also effectively prevent temperature overshoot after pressure relief.

[0061] Therefore, during the air extraction and / or pressure relief process, the value of a can be set slightly smaller, for example, smaller than the first value. The first value can be flexibly set according to actual conditions. For example, the first value can refer to the value of a set during the temperature rise process. That is, the value of a during the air extraction and / or pressure relief process can be smaller than the value of a set during the temperature rise process.

[0062] It should be known that t0 and a are interrelated. The essence of the parameter tuning strategy mentioned above to make a×t0=fixed value (such as 12) is to keep the maximum slope of the control curve at t0 at a relatively constant level, which helps to maintain the basic characteristics of the heating process of "fast in the middle and slow at both ends" under different heating times, and avoid affecting the efficiency by making the middle section too flat due to simply increasing t0. For negative pressure purification, especially multi-channel systems or processing heat-sensitive materials, it is recommended to use a smaller a (such as 0.01-0.05) with the corresponding t0 value to maximize its advantage in suppressing pumping / depressurization disturbances. The core advantages of using the above temperature model for temperature control are:

[0063] 1) Inherent smoothness and no overshoot

[0064] The above temperature model ensures that the temperature set value and its first-order derivative are continuous and finite, fundamentally eliminating the set value step jump. This is the basis for avoiding overshoot and oscillation of the PID controller due to sudden changes in the set value.

[0065] 2) Robustness against process disturbances

[0066] As mentioned above, selecting a smaller value for a results in a smoother setpoint change rate, providing a robust buffer against the dramatic thermal fluctuations inherent in negative pressure purification, caused by periodic pumping and depressurization (vacuum level fluctuations leading to sudden changes in heat transfer coefficient). The controller can more easily track these slowly changing setpoints, significantly reducing the fluctuations in actual process temperature during pumping and depressurization (e.g., from over ±5°C in traditional step control to within ±1°C) and recovery time, thereby improving process stability and consistency. This is difficult to achieve with existing step or simple PID control schemes.

[0067] 3) Process window optimization

[0068] The smooth temperature trajectory avoids the risk of thermal stress or microstructural changes in the material caused by rapid temperature fluctuations (especially sudden drops), widening the process window for safe operation. At the same time, compared with solvent extraction, this method saves time in solvent handling and drying steps.

[0069] 4) Flexibility of parameterization

[0070] Parameters t0 and a provide intuitive "knobs," allowing process engineers to fine-tune the process based on specific equipment, materials, vacuum system characteristics, and desired heating speed / softness, achieving tailored processing. For example, when processing high-value, heat-sensitive intraocular lenses, a large t0 and a small a value can be selected; when processing high-volume, heat-resistant materials, a smaller t0 and a slightly larger a value can be selected to balance efficiency.

[0071] Figures 2A to 2C A schematic diagram of the temperature rise curve is shown for different values ​​of a and t0 in the temperature model.

[0072] Figures 2A to 2C The horizontal axis of the temperature rise curve shown represents time (in seconds), and the vertical axis represents the temperature rise increment ratio. Figure 2A It shows the temperature rise curve when t0 is equal to 6s and a is equal to 1; Figure 2B It shows the temperature rise curve when t0 is equal to 300s and a is equal to 0.02; Figure 2C It shows the temperature rise curve when t0 is equal to 600s and a is equal to 0.01.

[0073] Combine Figures 2A to 2CAs can be seen, the temperature rise curve of the present disclosure is smooth and continuous. This smooth and continuous temperature change enables a wider process window, saving extraction time compared to solvent extraction, while achieving comparable purification results. Furthermore, it reduces overshoot during PID adjustment, achieving a fast and stable temperature setpoint.

[0074] As mentioned above, the values ​​of a and t0 can be set according to actual conditions. For example, during the process of pumping and depressurization, considering the heat capacity of the extraction box, the power of the heating module, and the characteristics of reduced heat transfer efficiency in a vacuum environment, in order to balance the heating efficiency and the ability to suppress the pumping / depressurization disturbance, you can choose Figure 2B or Figure 2C The temperature model shown in the figure is used to select a smaller a value and a larger t0 value. The smaller a value is selected to ensure that the maximum set value change rate near t0 is sufficiently gentle to effectively cope with the thermal disturbances generated during the pumping (pressure drop causes the effective thermal conductivity to drop) and pressure relief (pressure recovery). Figure 2B The temperature model shown was observed. The observation results show that after adopting this parameter combination, the maximum negative deviation of the actual temperature of the cavity relative to the set value during the vacuuming process (lasting 18 minutes) was suppressed to within -0.8°C (usually >-5'C under traditional step control), and it returned to the set value within 5 minutes after the end of the vacuuming. No significant overshoot was observed during the pressure relief process. The effectiveness of the model parameter adaptation setting in suppressing vacuum process disturbances was demonstrated. Therefore, the negative pressure purification scheme disclosed in the present invention can be regarded as a smooth temperature-varying negative pressure purification process. The process of using smooth temperature-varying negative pressure purification is intended to achieve: ① Smooth temperature change and high negative pressure to achieve a higher process control method. The smooth and continuous change of temperature can achieve a better process window, save more extraction time compared to the solvent extraction method, and achieve a purification effect equivalent to the solvent extraction method; ② It does not damage the surface of the material and does not affect the optical properties and physical and chemical properties of the material.

[0075] The smooth temperature-variable negative pressure purification process requires the use of a dedicated negative pressure extraction device. The extraction time is generally 3 to 9 days, preferably 3 to 7 days, and more preferably 3 to 5 days. Air needs to be filled in every 2 to 8 hours and a high negative pressure state needs to be maintained for a certain period of time. Both the air intake and exhaust processes require manual labor. This cumbersome process consumes a large amount of human resources, reduces production efficiency, and fails to achieve process consistency. Therefore, how to improve the purification efficiency of the artificial crystal material purification process while ensuring that the physical, chemical, and optical properties of the material are not affected and reducing the interference of uncontrollable factors in the purification process is a technical problem that urgently needs to be solved in the current mass production of artificial crystal materials.

[0076] In view of this, the present disclosure also designs a multi-channel extraction device, which is equipped with pipeline solenoid valve control, circuit boards, precise temperature control programs, and cycle programs for programming the operation of the multi-channel extraction device. It aims to achieve: ① The equipment can operate automatically according to pre-programmed programs. Set the control model parameters of smooth temperature change to realize the temperature switching process and smooth and precise control. The smooth temperature change negative pressure process can be unmanned and automatically executed; ② Automatic air intake and exhaust treatment can be realized at regular times every day, reducing the complexity of process operations and achieving high consistency of the process; ③ The multi-channel extraction device uses centralized control, which is more suitable for large-scale production and achieves better process stability.

[0077] Based on the above concept, the present disclosure proposes a negative pressure purification system, which can include multiple extraction boxes. The multiple extraction boxes can be one or more. The details of the present disclosure are further described below.

[0078] Figure 3 A schematic structural diagram of a negative pressure purification system of a single-channel extraction device according to an embodiment of the present disclosure is shown.

[0079] like Figure 3 As shown, the negative pressure purification system includes: an extraction chamber; a heating module (e.g., an electric heating module), a temperature sensor, a temperature transmitter, and a temperature controller (e.g., a precision temperature controller) associated with the extraction chamber. The temperature sensor and heating module are disposed within the chamber of the extraction chamber. The chamber of the extraction chamber may also be provided with a container for holding the intraocular material to be extracted. The temperature transmitter and temperature controller may be located outside the chamber. The chamber body of the extraction chamber may be formed of stainless steel or a nickel-chromium alloy.

[0080] The temperature sensor is used to detect the temperature signal in the cavity and send the detected temperature signal to the temperature transmitter. The temperature transmitter can convert the temperature signal into a standard signal and send it to the temperature controller.

[0081] In at least one of the heating process, the exhaust process, and the pressure relief process (for example, all processes), the temperature controller can control the working state of the heating module based on the standard signal so that the temperature in the cavity changes to the extraction temperature required for the extraction process according to the temperature rise curve represented by the temperature model. The heating process may refer to the process of changing the temperature in the cavity from room temperature to the extraction temperature in the initial state. The exhaust process refers to the process of extracting gas from the cavity to form a negative pressure (i.e., low pressure, such as vacuum negative pressure) in the cavity. The pressure relief process refers to the process of injecting gas into the cavity. The exhaust process and the pressure relief process are a reciprocating cycle. Each cycle includes an exhaust process and a pressure relief process.

[0082] In some embodiments, the temperature controller may determine whether a temperature increase is required based on the standard signal. If so, the temperature controller controls the operating state of the heating module so that the temperature within the chamber changes to the extraction temperature required for the extraction process according to the temperature rise curve represented by the temperature model. For example, the temperature controller may compare the temperature represented by the standard signal with the extraction temperature or the first temperature. If the temperature represented by the standard signal is lower than the extraction temperature and the difference between the two is greater than a certain threshold, or if the temperature represented by the standard signal is lower than the first temperature, the controller may trigger a smooth and continuous temperature change to achieve a smooth and continuous temperature change to the extraction temperature according to the temperature curve represented by the temperature model.

[0083] like Figure 3 As shown, the negative pressure purification system may also include a vacuum pump, a pressure transmitter, a vacuum pump inlet valve, a vacuum pump outlet valve, a stripping tank exhaust valve, a purge pressure relief valve, and a precision inlet regulating valve. The vacuum pump may be equipped with an exhaust port, an exhaust port, and an oil level gauge. The purge pressure relief valve should remain normally closed. The vacuum pump inlet valve, vacuum pump outlet valve, stripping tank exhaust valve, and precision inlet regulating valve can be opened or closed depending on operating conditions.

[0084] The vacuum pump's exhaust port is connected to the extraction box through a pipeline, providing a negative pressure state in the pipeline and discharging the residual gaseous monomer out of the cavity. A vacuum pump inlet valve and an extraction box exhaust valve are provided in the pipeline connecting the vacuum pump and the extraction box. The vacuum pump inlet valve is located near the vacuum pump. The extraction box exhaust valve is located near the extraction box and is used to lock the vacuum pressure inside the extraction box. The vacuum pump's exhaust port is connected to a ventilation system (such as a laboratory ventilation system) through a pipeline. A vacuum pump outlet valve is provided in the pipeline (i.e., the pipeline) connecting the vacuum pump's exhaust port to the ventilation system. The extraction box can also be connected to the atmosphere through a pipeline. A precision air intake regulating valve is provided in the pipeline connecting the extraction box and the atmosphere to allow a micro-flow of atmospheric air to enter the pipeline and smoothly release the vacuum pressure in the pipeline. A pressure transmitter can be used to detect the pressure signal in the pipeline so that it can be determined whether to end the extraction process based on the pressure signal during the extraction process.

[0085] exist Figure 3 In the exemplary embodiment shown, the air intake pipe where the vacuum negative pressure pump air intake valve is located, the air extraction pipe where the extraction box air extraction valve is located, and the atmospheric pipe where the air intake precision regulating valve is located can be connected through a tee piece.

[0086] The vacuum pump inlet valve, vacuum pump outlet valve, extraction box exhaust valve, and inlet precision regulating valve are collectively referred to as the pipeline solenoid valve group. The pipeline solenoid valve group has two main operating states: negative pressure state and atmospheric state, corresponding to the extraction and pressure relief processes in the extraction process, respectively.

[0087] Under negative pressure, the pipeline between the vacuum pump and the extraction box needs to be connected so that the vacuum pump's suction creates a negative pressure within the extraction box. Therefore, under negative pressure, the vacuum pump's inlet valve, outlet valve, and extraction box extraction valve must remain open, while the precision inlet valve must remain closed. For example, the sequence of valve operations under negative pressure is: close the precision inlet valve, open the extraction box extraction valve, open the vacuum inlet valve, and then open the vacuum outlet valve.

[0088] Under atmospheric conditions, the pipeline between the extraction box and the atmosphere needs to be connected to release the vacuum pressure inside the extraction box. Therefore, under atmospheric conditions, the vacuum pump's inlet valve needs to remain closed, while the extraction box's exhaust valve and the precision air inlet regulating valve need to remain open. For example, the valve operation sequence under atmospheric conditions is: close the vacuum pump's inlet valve, open the precision air inlet regulating valve, and then open the extraction box's exhaust valve. The vacuum pump's outlet valve can also remain closed.

[0089] Single-channel negative pressure extraction devices have low production efficiency and require manual timed gas replacement and pipeline switching operations, which are complex processes and cannot guarantee accurate time control. Based on the above research, this disclosure also provides a design for a multi-channel digital extraction device.

[0090] Figure 4 A schematic structural diagram of a negative pressure purification system of a multi-channel extraction device according to an embodiment of the present disclosure is shown.

[0091] and Figure 3 The difference shown is that in Figure 4 In the illustrated embodiment, a single vacuum pump can be connected in parallel to multiple extraction tanks via multiple conduits (e.g., vacuum pipes). The pipes can be made of silicone, white latex, polyurethane, or seamless stainless steel, with white latex being preferred. Connecting multiple extraction tanks in parallel with a vacuum pump means that each tank is independent and can simultaneously evacuate multiple tanks. This ensures that if a problem occurs in one tank, the others can continue to operate.

[0092] like Figure 4 As shown, the air intake precision regulating valve and the air extraction valve of the same extraction box are connected in series. This means that only when both the air intake precision regulating valve and the air extraction valve of the extraction box are open can the extraction box be connected to the atmosphere and atmospheric air enter the extraction box.

[0093] In this embodiment, centralized control is more suitable for large-scale production and can achieve better process stability.

[0094] In some embodiments, in order to enable the negative pressure purification system to automatically perform negative pressure purification on the material to be extracted, the negative pressure purification system may further include an automated control system. The automated control system may include a circuit board. The circuit board may be configured with a chip, input / output channels (IO channels) connected to various solenoid valves (such as the vacuum negative pressure pump air inlet valve, the vacuum negative pressure pump air outlet valve, the extraction box air extraction valve, and the air intake precision regulating valve), and a power management module for providing power management functions for each solenoid valve, the extraction box, and the vacuum negative pressure pump. The chip can be configured to perform an air extraction process and a pressure relief process for each extraction box at predetermined intervals according to the program. Thus, under the action of the automated control system, automatic air intake and air extraction processing can be achieved at regular times every day, reducing the complexity of the process operation and achieving high consistency of the process.

[0095] In some exemplary embodiments, the circuit board may also be configured with at least one of a network card, a display interface, and a USB interface, so that the device can be easily monitored and remotely controlled.

[0096] Figure 5 A schematic structural diagram of a single-chip microcomputer circuit board according to an embodiment of the present disclosure is shown.

[0097] like Figure 5 As shown, a custom single-chip microcomputer circuit board can be built. It features a display port and a USB port for conveniently monitoring the device's power-on status, along with a network card for remote control. Multiple power control circuits (corresponding to the power management module described above) and multiple solenoid valves are connected to the IO channels. The power supplies for the extraction chamber (including the extraction chamber temperature sensor, temperature transmitter, and temperature controller) and the vacuum pump are connected to the circuit board. The power supply for each solenoid valve connector is also connected to the circuit board, ultimately connecting the circuit board to a 220V power supply. A program loop is programmed to automatically open and close the vacuum pump according to the program. Simultaneously, a solenoid valve group controls the connection between each extraction chamber and the atmospheric line, allowing for sequential air pressure relief and negative pressure processing for each extraction chamber, enabling gas path switching between multiple extraction chambers.

[0098] The following is an illustrative description of the preparation work for each part of the negative pressure purification system.

[0099] 1) Preparation of the extraction box: The air release and pressure relief valve of the extraction box must be kept in a normally closed state, and the exhaust valve must be switched as needed. The power cord must remain connected, the start switch must be kept in the open state, and the power supply must be connected to the microcontroller circuit board. The program can control the power on and off effects.

[0100] 2) Preparation of the vacuum negative pressure pump: Install an exhaust pipe in the exhaust hole of the vacuum oil pump (i.e., vacuum negative pressure pump) and connect it to the laboratory ventilation system. Connect the air extraction hole to the vacuum pipe. Add vacuum pump oil to the oil gauge until the liquid level is within the range. Start the switch to save the open state and connect the power supply to the microcontroller circuit board. The program can control the power on and off effect.

[0101] 3) Configuration of vacuum pipeline: The vacuum pipeline uniformly uses 8*14 size. The pipeline material can be silicone, white latex, or polyurethane. This device uses white latex tube, which has a better sealing effect, can prevent volatile gas from escaping from the tube wall, and is thicker and pressure-resistant.

[0102] 4) Pipeline solenoid valve group: such as Figure 3 、 Figure 4 As shown, each passage is connected to a short section of white latex tube, then connected to a solenoid valve in the middle, and then connected to a white latex tube at the other end.

[0103] 5) Pipeline connection: Figure 3 、 Figure 4 As shown, connect the pipes and valves as shown in the figure, and connect the valve circuit to the microcontroller circuit board.

[0104] 6) Design of MCU circuit board: Customize a MCU circuit board, the design diagram is as attached Figure 5 As shown, it is equipped with a display interface and USB interface for convenient monitoring of the device's power-on status, and a network card for remote control. It has multiple power control circuits and multiple solenoid valves connected to the IO channels. The power supply of the extraction box and vacuum pump is connected to the circuit board, and the power supply of each solenoid valve connector is connected to the circuit board. The circuit board is finally connected to a 220V power supply.

[0105] 7) Editing of startup program: The startup program of one cycle of extraction box is as follows Figure 6 The extraction box set to start will be used for smooth temperature-variable negative pressure purification process, and the extraction box will be switched to vacuum state. The specific process will be as follows Figure 6 The set values ​​can be adjusted according to the actual situation. After the last process is completed, the exhaust valve and vacuum negative pressure pump are closed to save energy. After the extraction box of the process group has been running for a total of 3 hours, the extraction box is switched to the atmospheric state according to the program to release the high-concentration residual monomer again. After the atmospheric state process is completed, this is a complete extraction process program. By using this program, the working condition of one vacuum pump controlling one extraction box can be simulated, thereby realizing one vacuum pump controlling multiple extraction boxes. This cycle program is set to cycle 3 to 5 times a day, which can be unmanned.

[0106] This disclosure also proposes a negative pressure purification method. This method includes controlling the temperature within an extraction chamber to a desired extraction temperature according to a temperature rise curve characterized by a temperature model during at least one of a heating process, a gas extraction process, and a pressure relief process. For details on the temperature model, please refer to the above description.

[0107] The disclosed negative pressure purification method can be used to purify intraocular lens materials (such as foldable intraocular lens materials) under negative pressure. First, the intraocular material to be extracted is prepared, and the exact mass of the material to be extracted is weighed and recorded. The synthesized intraocular material is then placed in a glass watch glass, spread out in sequence, and extracted and purified using an extraction device (i.e., an extraction box).

[0108] The extraction device's air extraction valve interface is connected to a vacuum generating device (i.e., a vacuum negative pressure pump), which is then connected to a vacuum pipeline. The extraction device and other valves in the pipeline are closed to create a low negative pressure state within the device cavity. Preferably, the negative pressure within the cavity is 10 Pa to 500 Pa, more preferably 100 Pa to 200 Pa. For details about the extraction device, vacuum generating device, and the process of creating the low negative pressure state, please refer to the relevant descriptions above.

[0109] The extraction process parameters used in the present disclosure can be set as follows. The extraction temperature can be 40°C to 90°C, preferably 70°C to 90°C. The extraction time is 5 minutes to 30 minutes, preferably 5 minutes to 20 minutes. The extraction time is 3 days to 9 days, preferably 3 days to 7 days, and more preferably 3 days to 5 days. An extraction cycle is performed every 2 hours to 8 hours (preferably 4 hours to 8 hours), and each extraction cycle includes a extraction process and a pressure relief process.

[0110] After the extraction process is completed, the change in the residual rate and the mechanical and optical properties of the test material can also be determined.

[0111] The process for determining the change in residual rate is as follows: Place the IOL material in the extraction box into a desiccator for natural cooling, weigh the cooled IOL material, and calculate the change in the material residual rate based on the weight before extraction. A 4-digit precision balance can be used to measure the weight difference before and after the material is weighed, and then the weight difference can be calculated. The larger the value obtained from the test of samples from the same batch, the better the extraction effect. The calculation method refers to the following formula:

[0112]

[0113] The process for testing the mechanical properties of the material is to mill the haptic using the milling process for conventional intraocular lenses and then test the tensile strength using a haptic tensile strength testing machine. Mechanical properties are expressed as tensile strength using a haptic tensile strength testing machine. The test method is based on the standard YY0290.3-2018 Ophthalmic Optics Intraocular Lenses Part 3: Mechanical Properties and Test Methods. The haptic tensile strength requirement is ≥ 0.25N, and the higher the value, the better the optical performance.

[0114] The optical performance testing process involves measuring the modulation transfer function (MTF) of the IOL material using an IOL optical measuring instrument. This measurement must be performed within the simulated eye system specified in YY0290.2-2021, with an aperture of 3mm and a spatial frequency of 100mm-1. Higher values ​​indicate better optical performance.

[0115] The present disclosure also provides examples and comparative examples to compare the performance differences between the smooth temperature-variable negative pressure purification technology and the organic solvent extraction technology.

[0116] Example

[0117] Preparation of materials: First, weigh the material to be extracted accurately and record the mass. Then, place the synthesized artificial lens material into a glass watch glass, spread it out in sequence, and use an extraction box for extraction.

[0118] Temperature control: Use continuous smooth temperature model Where t0 is equal to 300s and a is equal to 0.02.

[0119] Setting of extraction box and pipeline: In the connected negative pressure extraction box, vacuum negative pressure pump and multiple pipelines connected to the atmosphere, there are pipeline solenoid valves to enable the extraction device to switch to negative pressure state and release pressure to normal pressure state.

[0120] ①Start the vacuum pump body first

[0121] ② Switch the solenoid valve group to negative pressure state. Close the air inlet precision regulating valve, open the extraction box exhaust valve, open the vacuum negative pressure air inlet valve, and open the vacuum negative pressure air outlet valve.

[0122] ③Maintain negative pressure for a certain process time

[0123] ④ Switch the solenoid valve group to the pressure relief atmospheric state. The valve action sequence is: close the vacuum negative pressure inlet valve, open the air inlet precision regulating valve, and open the extraction box exhaust valve.

[0124] Extraction process: extraction temperature is 40-90℃, extraction time is 10min, extraction time is 3-9 days, and air intake and extraction cycle needs to be performed every 4-6 hours. Figures 7B to 7EThe specific temperature, extraction interval time, extraction time combination information, as well as the residual rate change, mechanical properties, and optical properties data before and after extraction are shown in the examples. Each set of samples uses one piece of material.

[0125] Regarding the determination of the change in the residual rate, the mechanical property test of the material, and the optical property test of the material, please refer to the description above.

[0126] Comparative Example

[0127] Material preparation: First, weigh the exact mass of the material to be extracted and record it, then place the synthesized intraocular lens material into a small glass bottle.

[0128] Preparation of solvent: Add 20 times the mass of the material into a small glass bottle for extraction. The solvent can be acetonitrile, n-hexane, acetone, saline, ethanol, methanol, and the extraction time is 3 to 7 days. Figure 7A To provide the specific solvent type and extraction time combination information of the comparative examples, as well as the residual rate changes, mechanical properties, and optical properties data before and after extraction, one piece of material was used for each set of samples.

[0129] Extraction process: After the extraction is completed, the synthesized artificial crystal material is placed in a glass watch glass, spread out in sequence, and then placed in a vacuum drying oven. The temperature is set to 70°C, and the air is pumped in and out every 8 hours for extraction for 3 days.

[0130] Regarding the determination of the change in the residual rate, the mechanical property test of the material, and the optical property test of the material, please refer to the description above.

[0131] The examples were analyzed using different solvents and different temperatures and times during smooth temperature-variable negative pressure purification. 7A to 7E Schematic diagrams of specific performance data of comparative examples and embodiments are shown.

[0132] As mentioned above, the use of organic solvent extraction may lead to significant changes in optical properties. 7A to 7E The experimental data shown show that the technique using smooth temperature-varying negative pressure purification can achieve almost the same residue rate but with better optical performance.

[0133] Compared with organic solvent extraction, smooth temperature-variable negative pressure purification technology has the following advantages: ① It reduces the impact of organic solvents on optical imaging quality after contact with intraocular materials; ② It reduces the use and pollution of organic solvents; ③ After using smooth temperature-variable negative pressure purification technology, it can more effectively reduce the monomer residual rate and ensure that the performance of other materials is not affected.

[0134] In addition, compared with single-channel technology, multi-channel has the following advantages: ① Saves labor costs and improves production efficiency: By programming automation programs and utilizing the characteristics of electronic control of pipeline solenoid valve groups, the extraction box automatically performs timed and fixed air intake and exhaust operations. It achieves an unmanned effect, saves labor costs, improves production efficiency, and achieves a high degree of process consistency. ② More energy-saving: By accurately designing the pump start time, it can avoid energy waste caused by long-term pump start-up and avoid the tediousness of manual timing and start-up. ③ Good for the environment: Vacuum pump oil has a service life and shelf life, needs to be replaced regularly, and has certain pollution, so it needs to be sent to a specialized qualified agency for treatment. Using only one vacuum pump can reduce the large-scale replacement of vacuum pump oil, which is beneficial to pump oil waste and environmental protection.

[0135] While various embodiments of the present invention have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A negative pressure purification system comprising: Several extraction boxes; heating modules, temperature sensors, temperature transmitters and temperature controllers associated with each of the extraction boxes, The temperature sensor and the heating module are arranged in the cavity of the extraction box. The temperature sensor sends the detected temperature signal to the temperature transmitter. The temperature transmitter converts the temperature signal into a standard signal and sends it to the temperature controller. During at least one of the heating process, the gas extraction process, and the pressure relief process, the temperature controller controls the working state of the heating module based on the standard signal so that the temperature in the chamber changes to the extraction temperature required by the extraction process according to the temperature rise curve represented by the temperature model. The temperature model is expressed as Wherein, a is the temperature rise slope, t0 is the time required to heat to half the extraction temperature, t is any time, f(t) represents the incremental ratio of temperature rise at time t, and the incremental ratio of temperature rise represents the ratio of the current temperature rise to the total temperature rise. The current temperature rise is equal to the current temperature minus the initial temperature, and the total temperature rise is equal to the extraction temperature minus the initial temperature.

2. The negative pressure purification system according to claim 1, further comprising: Vacuum negative pressure pump, The air extraction holes of the vacuum negative pressure pump are connected to the respective extraction boxes through pipelines. A vacuum negative pressure pump air inlet valve and an extraction box air extraction valve are provided in the pipelines connecting the air extraction holes of the vacuum negative pressure pump and the extraction boxes. The vacuum negative pressure pump air inlet valve is provided close to the vacuum negative pressure pump, and the extraction box air extraction valve is provided close to the extraction boxes. The exhaust hole of the vacuum negative pressure pump is connected to the ventilation system through a pipeline, and a vacuum negative pressure pump outlet valve is provided in the pipeline connecting the exhaust hole of the vacuum negative pressure pump and the ventilation system.

3. The negative pressure purification system according to claim 2, wherein: The extraction box is also connected to the atmosphere through a pipeline. An air intake precision regulating valve is also provided in the pipeline connecting the extraction box and the atmosphere.

4. The negative pressure purification system according to claim 3, wherein: The vacuum negative pressure pump is connected in parallel with the plurality of extraction boxes through a plurality of pipes. The air intake precision regulating valve and the air extraction valve of the extraction box belonging to the same extraction box are in a series structure.

5. The negative pressure purification system according to claim 4, wherein: During the air extraction process, the extraction valve of the extraction box, the air inlet valve of the vacuum negative pressure pump, and the air outlet valve of the vacuum negative pressure pump are all set to the open state, and the air inlet precision regulating valve is set to the closed state; During the pressure relief process, the extraction box air extraction valve and the air intake precision regulating valve are set to the open state, and the vacuum negative pressure pump air intake valve is set to the closed state.

6. The negative pressure purification system according to claim 5, further comprising: An automated control system includes a circuit board, on which are configured a chip, input / output channels, and a power management module. The input / output channels are respectively connected to the vacuum negative pressure pump inlet valve, the vacuum negative pressure pump outlet valve, the extraction box exhaust valve, and the air intake precision regulating valve. The power management module is used to provide power management functions for the vacuum negative pressure pump, the extraction box, the vacuum negative pressure pump inlet valve, the vacuum negative pressure pump outlet valve, the extraction box exhaust valve, and the air intake precision regulating valve. The chip is configured to perform an exhaust process and a pressure relief process for the extraction box at predetermined intervals according to a program.

7. The negative pressure purification system according to claim 6, wherein: The circuit board is also configured with at least one of a network card, a display interface, and a USB interface.

8. The negative pressure purification system according to claim 1, wherein: The value of t0 is set based on the system's comprehensive resistance to the heating rate, and the value of t0 is positively correlated with the comprehensive resistance.

9. The negative pressure purification system according to claim 8, wherein: The value of t0 is positively correlated with the thermal capacity of the extraction chamber and its internal structure; and / or the value of t0 is negatively correlated with the maximum available power of the heating module; and / or The value of t0 is positively correlated with the total mass of material in the extraction chamber that needs to be purified under negative pressure; and / or The value of t0 is positively correlated with the specific heat capacity of the material to be purified under negative pressure in the extraction chamber; and / or The value of t0 is positively correlated with the effective heat loss coefficient of the system; and / or The value of t0 is positively correlated with the degree of gentleness required by the process; and / or The value of t0 is positively correlated with the vacuum degree.

10. The negative pressure purification system according to claim 1, wherein: During the air extraction process and / or the pressure relief process, the value of a is lower than the first value.

11. The negative pressure purification system according to any one of claims 1 to 10, wherein: The negative pressure purification system is used for performing negative pressure purification on artificial lens materials.

12. A negative pressure purification method comprising: During at least one of the temperature rising process, the air pumping process, and the pressure relief process, the temperature in the extraction box is controlled to change to the extraction temperature required by the extraction process according to the temperature rising curve represented by the temperature model. The temperature model is expressed as Wherein, a is the temperature rise slope, t0 is the time required to heat to half the extraction temperature, t is any time, f(t) represents the incremental ratio of temperature rise at time t, and the incremental ratio of temperature rise represents the ratio of the current temperature rise to the total temperature rise. The current temperature rise is equal to the current temperature minus the initial temperature, and the total temperature rise is equal to the extraction temperature minus the initial temperature.

13. The method according to claim 12, wherein: The method is used to perform negative pressure purification on artificial lens materials. The extraction temperature is 40°C to 90°C; and / or The pumping time is 5 to 30 minutes; and / or The extraction time is 3 to 9 days; and / or A vacuum cycle is performed every 2 to 8 hours; each vacuum cycle includes a vacuum process and a pressure relief process.

14. The method according to claim 13, further comprising: Place the intraocular lens material in the extraction box into a desiccator for natural cooling, weigh the cooled intraocular lens material, and calculate the change in the material residual rate based on the weight before extraction; and / or Milling the IOL material's haptics and testing its tensile strength using a haptic tensile strength testing machine; and / or The modulation transfer function of intraocular lens materials is tested using an intraocular lens optical measuring instrument.

15. The method according to claim 12, further comprising: The value of t0 is set based on the system's comprehensive resistance to the heating rate, and the value of t0 is positively correlated with the comprehensive resistance.

16. The method according to claim 15, wherein The value of t0 is positively correlated with the thermal capacity of the extraction chamber and its internal structure; and / or the value of t0 is negatively correlated with the maximum available power of the heating module; and / or The value of t0 is positively correlated with the total mass of material in the extraction chamber that needs to be purified under negative pressure; and / or The value of t0 is positively correlated with the specific heat capacity of the material to be purified under negative pressure in the extraction chamber; and / or The value of t0 is positively correlated with the effective heat loss coefficient of the system; and / or The value of t0 is positively correlated with the degree of gentleness required by the process; and / or The value of t0 is positively correlated with the vacuum degree.

17. The method according to claim 12, wherein: During the air extraction process and / or the pressure relief process, the value of a is lower than the first value.

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