Powder material packaging method, finished product, control method, control device and system

Abstract

The application relates to the technical field of powder material packaging, and provides a powder material packaging method, a finished product, a control method, a control device and a system. The powder material packaging finished product is obtained through the following powder material packaging method: powder material to be packaged is loaded into a packaging bag, the packaging bag is pre-sealed, and an opening is reserved; the packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening; wherein each replacement cycle comprises a vacuum extraction stage and a protective gas filling stage, after the vacuum extraction stage of the current replacement cycle is completed, the current actual oxygen concentration in the packaging bag is obtained, and the operation parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration; after the last protective gas filling stage is completed, the reserved opening is closed. The application can effectively reduce the residual oxygen concentration of the powder material packaging finished product.

Description

Technical Field

[0001] This application relates to the field of powder material packaging technology, and in particular to a powder material packaging method, finished product, control method, control equipment and system. Background Technology

[0002] Powder materials have wide applications in chemical, new energy, pharmaceutical, and food industries. Some powder materials are extremely sensitive to oxygen and readily undergo oxidation upon contact with air, leading to performance degradation, reduced effective components, and even safety hazards. For example, lithium iron phosphate and ternary materials, used as cathode materials in new energy batteries, are prone to oxidation when exposed to oxygen-containing environments for extended periods, affecting their subsequent electrochemical performance and cycle life in batteries. Similarly, some metal powders and pharmaceutical raw material powders also have stringent requirements regarding the residual oxygen content in the packaging environment. Therefore, after the aforementioned powder materials are produced and before entering downstream applications, they require proper anti-oxidation packaging.

[0003] Currently, the industry commonly uses a vacuum-protective gas replacement process for packaging powder materials to prevent oxidation. This involves placing the powder material in a bag, then sequentially vacuuming and filling the bag with protective gas through a pre-drained opening to gradually replace the air inside with the protective gas. Alternatively, positive pressure protection with protective gas can be used directly. However, even after packaging using these methods, the residual oxygen concentration inside the bag remains high, reaching 1000 ppm-3000 ppm, with the oxidation rate of the powder material exceeding 0.5%, leading to significant volume decay during storage. Furthermore, these methods typically use fixed parameters, resulting in energy waste or excessive residual oxygen levels under certain operating conditions.

[0004] Therefore, how to effectively reduce the residual oxygen concentration in finished powder packaging products is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This application aims to solve the technical problems existing in the related technologies. To this end, this application proposes a powder material packaging method, finished product, control method, control equipment and system, which can effectively reduce the residual oxygen concentration of the packaged powder material finished product.

[0006] In a first aspect, embodiments of this application provide a finished powder material package, which is obtained by packaging the powder material using the following powder material packaging method: The powder material to be packaged is placed into a packaging bag, and the packaging bag is pre-sealed, leaving an opening. The packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening; wherein each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration. After the final protective gas filling stage is completed, the reserved opening is sealed.

[0007] Secondly, embodiments of this application provide a method for packaging powder materials, including: The powder material to be packaged is placed into a packaging bag, and the packaging bag is pre-sealed, leaving an opening. The packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening; wherein each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration. After the final protective gas filling stage is completed, the reserved opening is sealed.

[0008] Thirdly, embodiments of this application provide a powder material packaging control device, which is configured to perform the following steps: Control the vacuum valve and the gas filling valve to perform at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged; Each replacement cycle includes a vacuuming phase and a protective gas filling phase. After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

[0009] Fourthly, embodiments of this application provide a method for controlling the packaging of powder materials, including: Control the vacuum valve and the gas filling valve to perform at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged; Each replacement cycle includes a vacuuming phase and a protective gas filling phase. After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

[0010] Fifthly, embodiments of this application provide a powder material packaging system, including a packaging cavity, a vacuum pipeline, a protective gas filling pipeline, an oxygen sensor, and a powder material packaging control device as described in the third aspect; wherein, The packaging cavity is used to accommodate a pre-sealed packaging bag containing powder material to be packaged and with an opening. The vacuuming pipeline and the protective gas filling pipeline are respectively connected to the opening of the packaging bag through a vacuum valve and a gas filling valve, and are used to perform vacuum-protective gas replacement cycle on the packaging bag; The oxygen sensor is used to obtain the current actual oxygen concentration inside the packaging bag; The powder material packaging control equipment is electrically connected to the oxygen sensor, the vacuum valve, and the inflation valve, respectively.

[0011] According to the embodiments of this application, the finished powder material packaging product is obtained by the following powder material packaging method: the powder material to be packaged is placed into a packaging bag, the packaging bag is pre-sealed, leaving an opening; the packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening; wherein, each replacement cycle includes a vacuuming stage and a protective gas filling stage, after the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration in the packaging bag is obtained, and the operating parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration; after the last protective gas filling stage is completed, the reserved opening is closed.

[0012] The above technical solution has the following advantages or beneficial effects: In the packaging process of powder materials, this application embodiment performs multiple vacuum-protective gas replacement cycles, and determines the operating parameters of subsequent replacement cycles based on the current actual oxygen concentration during each replacement cycle. By combining multiple vacuum-protective gas replacement cycles with adaptive control, the residual oxygen concentration of the packaged powder material is effectively reduced.

[0013] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application and are not considered as limitations on this application. Moreover, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is one of the flowcharts illustrating the powder material packaging method provided in the embodiments of this application.

[0016] Figure 2 This is the second schematic flowchart of the powder material packaging method provided in the embodiments of this application.

[0017] Figure 3This is a schematic diagram of the structure of the powder material packaging control equipment provided in this application.

[0018] Figure 4 This is one of the flowcharts illustrating the powder material packaging control method provided in the embodiments of this application.

[0019] Figure 5 This is the second flowchart illustrating the powder material packaging control method provided in the embodiments of this application.

[0020] Figure 6 This is the third flowchart of the powder material packaging control method provided in the embodiments of this application.

[0021] Figure 7 This is the fourth flowchart of the powder material packaging control method provided in the embodiments of this application.

[0022] Figure 8 This is the fifth flowchart illustrating the powder material packaging control method provided in the embodiments of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] The following is combined with Figures 1 to 8 This application describes the powder material packaging method, finished product, control method, control equipment, and system.

[0025] Powder materials have wide applications in chemical, new energy, pharmaceutical, and food industries. Some powder materials are extremely sensitive to oxygen and readily undergo oxidation upon contact with air, leading to performance degradation, reduced effective components, and even safety hazards. For example, powdered cathode materials used in new energy batteries are prone to oxidation when exposed to oxygen-containing environments for extended periods, affecting their subsequent electrochemical performance and cycle life within the battery. In particular, lithium iron phosphate (LiFePO4), as a cathode material for lithium-ion batteries, possesses high safety, ultra-long cycle life (up to tens of thousands of cycles), and significant cost advantages. It not only holds a dominant market share in the new energy vehicle sector but is also the preferred material for electrochemical energy storage systems, providing crucial support for the widespread adoption of renewable energy. However, lithium iron phosphate (LiFePO4) is easily oxidized in air, and the Fe... 2+ It will be converted into Fe 3+This leads to a decrease in material capacity and an increase in impedance, severely affecting battery performance.

[0026] Therefore, how to effectively suppress the oxidation and deterioration of powder materials during storage and transportation, while also taking into account energy consumption control, is a technical problem that urgently needs to be solved in this field.

[0027] This application provides a finished powder material packaging product, which is obtained by the following powder material packaging method.

[0028] Figure 1 This is one of the flowcharts illustrating the powder material packaging method provided in the embodiments of this application, such as... Figure 1 As shown, the powder material packaging method includes steps S110, S120 and S130.

[0029] Step S110: The powder material to be packaged is put into a packaging bag, and the packaging bag is pre-sealed, leaving an opening.

[0030] Pre-sealing refers to the process of sealing part of the edge of a packaging bag. The purpose is to create a sealed cavity except for the reserved opening, thus creating the preconditions for subsequent vacuum-protective gas replacement cycle.

[0031] Protective gas refers to a gas that is chemically stable to powder materials and does not undergo oxidation or other side reactions. It can be an inert gas such as nitrogen or argon, or a non-reactive gas.

[0032] The powder material to be packaged is placed into a packaging bag, and three sides of the bag are heat-sealed, leaving one side open for later use. This opening is used to connect to the vacuum pumping line and the protective gas filling line for vacuum-protective gas replacement cycle.

[0033] In one embodiment, before the powder material to be packaged is put into the packaging bag, the powder material to be packaged is pre-treated, such as by sieving, in order to improve the quality of the finished product.

[0034] In one embodiment, the powder material is a battery positive electrode material, and the packaging bag is an aluminum-plastic composite bag. Battery positive electrode materials are easily oxidized in air; by using an aluminum-plastic composite bag with good gas barrier properties, external oxygen and water vapor can be effectively prevented from penetrating into the bag.

[0035] Furthermore, in one embodiment, the positive electrode material of the battery is a ternary material, such as nickel-cobalt-manganese (NCM) or nickel-cobalt-aluminum (NCA), and the corresponding protective gas is nitrogen.

[0036] In another embodiment, the positive electrode material of the battery is lithium iron phosphate powder, and the corresponding protective gas is nitrogen.

[0037] Furthermore, in one embodiment, if the powder material to be packaged is lithium iron phosphate powder material, it is first subjected to pre-processing such as sieving and iron removal before being packed into packaging bags.

[0038] Step S120: Perform at least two vacuum-protective gas replacement cycles on the packaging bag through the opening; wherein each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, obtain the current actual oxygen concentration inside the packaging bag, and determine the operating parameters of the subsequent replacement cycle based on the current actual oxygen concentration.

[0039] Vacuum-protective gas replacement cycle refers to a cycle in which a portion of the mixed gas is first extracted by a vacuum pump to reduce the total pressure, and then a pure protective gas (such as nitrogen) is introduced to increase the total pressure, thereby significantly reducing the mole fraction of the original gas (such as oxygen) by utilizing the principle of ideal gas dilution.

[0040] By connecting the packaging bag to the vacuum line and the protective gas line through the opening, at least two vacuum-protective gas replacement cycles are performed on the packaging bag sequentially. Each replacement cycle consists of two sequential sub-stages: (1) Vacuuming stage: Open the vacuum valve, close the inflation valve, and use the vacuum pump to extract the mixed gas in the packaging bag, so that the absolute pressure in the packaging bag is reduced to the target vacuuming pressure. (2) Protective gas filling stage: Close the vacuum valve, open the filling valve, and fill the packaging bag with protective gas through the protective gas filling pipeline to raise the absolute pressure inside the packaging bag to the target filling pressure.

[0041] It should be understood that the target vacuum pressure and target inflation pressure are different for different sequences of replacement cycles, and can be preset according to actual needs. No specific limitation is made here.

[0042] After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

[0043] In one embodiment, an oxygen sensor installed on the vacuum line, adjacent to the packaging bag, acquires the current actual oxygen concentration of the gas extracted from the packaging bag during the vacuum phase of the current replacement cycle. Installing the oxygen sensor close to the packaging bag avoids dilution by ambient air, ensuring the accuracy of the current actual oxygen concentration measurement.

[0044] In one embodiment, after the vacuuming phase of the current displacement cycle is completed (i.e., the current target vacuum pressure is reached), the vacuum valve is closed; a preset stabilization time (e.g., 3 seconds) is waited for the gas in the pipeline to diffuse evenly, and then the oxygen concentration value of the oxygen sensor is read and used as the current actual oxygen concentration. By waiting for the preset stabilization time, the accuracy of the current actual oxygen concentration measurement can be further improved.

[0045] In one embodiment, the current target oxygen concentration threshold corresponding to the current displacement cycle sequence is obtained. If the current actual oxygen concentration is greater than the current target oxygen concentration threshold, the operating parameters of subsequent displacement cycles are adjusted according to the current actual oxygen concentration. If the current actual oxygen concentration is less than or equal to the current target oxygen concentration threshold, no adjustment of the operating parameters of subsequent displacement cycles is required, and the operating parameters of subsequent displacement cycles continue to be executed according to the set operating parameters. If the current actual oxygen concentration is less than or equal to the final target oxygen concentration threshold, the displacement cycle ends. The final target oxygen concentration threshold is less than the current target oxygen concentration threshold and is set based on the finished product packaging standard; for example, it can be set to 0.01%, i.e., 100 ppm. The specific execution process can be referred to in the embodiments of the powder packaging material control method described below, and will not be elaborated here.

[0046] Step S130: After the final protective gas filling stage is completed, the reserved opening is closed.

[0047] After determining that the replacement cycle is over and completing the final protective gas filling stage, close the reserved opening to complete the final sealing of the packaging bag.

[0048] In one embodiment, the reserved opening is heat-sealed by a heat-sealing mechanism.

[0049] The powder material packaging method provided in this application involves placing the powder material to be packaged into a packaging bag, pre-sealing the bag, and leaving an opening. Then, the packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening. Each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on this concentration. After the final protective gas filling stage, the reserved opening is closed. In this application embodiment, by performing multiple vacuum-protective gas replacement cycles during the powder material packaging process, and determining the operating parameters for subsequent replacement cycles based on the obtained current actual oxygen concentration during each replacement cycle, the combination of multiple vacuum-protective gas replacement cycles and adaptive control effectively improves the deoxygenation effect. It is also compatible with packaging powder materials from different batches and in different packaging scenarios, avoiding insufficient deoxygenation or energy waste due to environmental or material fluctuations.

[0050] Furthermore, the finished powder packaging product obtained by this powder packaging method effectively reduces the residual oxygen concentration of the finished powder packaging product.

[0051] Based on any of the above embodiments, the absolute pressure of the target vacuum pressure in each vacuuming stage is set to increase incrementally as the order of the displacement cycle increases.

[0052] The absolute pressure of the target vacuum pressure in each vacuuming stage during at least two vacuum-protective gas replacement cycles. (where k represents the k-th permutation cycle, (The unit is kPa) is set according to the following rules: .

[0053] That is, as the number of replacement cycles increases, the absolute pressure of the target vacuum pressure increases. Numerically, the lower the absolute pressure, the higher the vacuum level and the more thorough the evacuation. Deep evacuation is performed in the early stage of replacement (when there is more air in the bag and the powder is compacted), while moderate shallow evacuation is performed in the later stage of replacement (when there is less gas in the bag and the powder is loose).

[0054] Furthermore, to avoid dust generation, the vacuum pressure cannot be too low; generally... .

[0055] In one embodiment, during the first replacement, a lower vacuum pressure (e.g., 5 kPa) is used to quickly remove most of the air; during the second replacement, the vacuum pressure is slightly increased (e.g., 8 kPa) to avoid powder dust; during the third replacement, the vacuum pressure can be increased to 10 kPa.

[0056] The powder material packaging method provided in this application effectively reduces airflow disturbance in subsequent cycles by progressively increasing the absolute pressure of the target vacuum pressure in each vacuuming stage. Under the premise of ensuring deoxygenation, it solves the problem of powder dust extraction, protects the vacuum pump from dust wear, and reduces material loss.

[0057] Based on any of the above embodiments, step S130 includes: step S131.

[0058] Step S131: After the last protective gas filling stage is completed, control the pressure inside the packaging bag to a slightly positive pressure state that is higher than the external atmospheric pressure, and close the reserved opening under the slightly positive pressure state.

[0059] After the final protective gas filling stage is completed, the pressure inside the packaging bag is controlled to be in a slightly positive pressure state higher than the external atmospheric pressure, for example, 0.01 MPa-0.02 MPa higher than the external atmospheric pressure. Then, the heat sealing mechanism is activated to heat seal the reserved opening to complete the final sealing of the packaging bag, that is, all four sides of the packaging bag are sealed.

[0060] The powder material packaging method provided in this application embodiment controls the pressure inside the packaging bag to a slightly positive pressure state, so that when the reserved opening is closed, outside air cannot flow back in, thereby locking in a low-oxygen pure nitrogen environment inside the packaging.

[0061] Based on any of the above embodiments, the packaging bag is provided with a microporous breathable membrane.

[0062] Considering that changes in ambient temperature or atmospheric pressure cause the gas inside the bag to expand and contract, leading to bulging (making it prone to breakage) or denting (drawing in air) and causing secondary oxidation, traditional packaging bags lack pressure balance design, resulting in poor sealing reliability. Therefore, in this embodiment, a microporous breathable membrane is provided on the packaging bag. The inner side of this microporous breathable membrane communicates with the inner cavity of the packaging bag, while the outer side communicates with the external atmosphere, ensuring that the packaging bag still has a bidirectional gas balance channel after sealing.

[0063] In one embodiment, a microporous breathable membrane is embedded in the body of the packaging bag beforehand during the empty bag manufacturing stage by means of hot melt bonding or adhesive bonding process.

[0064] In one embodiment, the microporous breathable membrane is disposed at the reserved edge of the upper side or top of the packaging bag. Specifically, for vertically sealed packaging bags, the microporous breathable membrane is preferably disposed at the top of the bag, for example, in the area 5cm-10cm below the heat-sealed edge of the bag opening; for packaging bags transported horizontally, the microporous breathable membrane is preferably disposed at the upper side of the bag so that the membrane surface remains facing upward when the bag is tilted or turned over, avoiding direct coverage of powder.

[0065] It should be noted that because powder materials such as lithium iron phosphate are extremely fluid and fine, if the microporous breathable membrane is placed at the bottom or lower part of the packaging bag, the powder can easily physically bury and block the micropores under the heavy pressure of stacking during transportation, rendering the membrane unable to allow air to pass through. Placing the microporous breathable membrane at the reserved edge on the upper side or top ensures that it can work effectively under various transportation conditions.

[0066] The powder material packaging method provided in this application has a very low permeability of oxygen molecules to the microporous breathable membrane, but it has normal gas passage capacity when the internal and external pressure difference is too large. Therefore, by setting a microporous breathable membrane on the packaging bag, the problem of bag bursting / collapse caused by excessive internal and external pressure difference in extreme logistics environments can be solved without significantly damaging the low oxygen environment inside the bag, thereby improving the adaptability of powder material packaging for finished product transportation.

[0067] Based on any of the above embodiments, the microporous breathable membrane is made of polytetrafluoroethylene or polypropylene, the pore size of the microporous breathable membrane is 0.1 μm-0.5 μm, and the oxygen permeability of the microporous breathable membrane is not greater than 0.5 cm. 3 / (m 2 (24h·atm). The microporous breathable membrane is made of polytetrafluoroethylene or polypropylene, the pore size of the microporous breathable membrane is 0.1 μm-0.5 μm, and the oxygen permeability of the microporous breathable membrane is not greater than 0.5 cm. 3 / (m 2 ·24h·atm).

[0068] The microporous breathable membrane is made of polytetrafluoroethylene (PTFE) or polypropylene (PP), both of which have excellent hydrophobicity and chemical stability.

[0069] The microporous breathable membrane has a pore size of 0.1 μm-0.5 μm. This pore size range can block liquid water penetration and lithium iron phosphate powder leakage, while ensuring gas passage.

[0070] The oxygen transmission rate (OTR) of the microporous breathable membrane is no greater than 0.5 cm. 3 / (m 2 The test method is based on ASTM D3985 standard (24h·atm). Under this OTR parameter, it is extremely difficult for oxygen from the external environment to penetrate into the packaging bag, which can effectively prevent secondary oxidation of powder materials during transportation and storage.

[0071] Based on any of the above embodiments Figure 2 This is the second flowchart illustrating the powder material packaging method provided in this application, as shown below. Figure 2 As shown, the powder material packaging method further includes steps S141, S142 and S143.

[0072] Step S141: Inject a preset volume of test gas into a closed chamber, which is formed on the outside of the microporous breathable membrane by covering the microporous breathable membrane with a detection head with a sealing ring.

[0073] A detection head with a sealing ring is used to cover the microporous breathable membrane to form a closed chamber on the outside of the microporous breathable membrane.

[0074] After the microporous breathable membrane is placed on the packaging bag, a special detection head with a sealing ring is used to cover the area of ​​the microporous breathable membrane to form a closed chamber on the outside of the microporous breathable membrane.

[0075] A predetermined volume of test gas is injected into a sealed chamber using a syringe or a precision air pump.

[0076] In one embodiment, a preset volume The volume is 3mL-7mL, for example, 5mL.

[0077] In one embodiment, the test gas is air.

[0078] Step S142: Obtain the pressure rise time required for the pressure in the sealed chamber to rise from the initial pressure to the preset target pressure.

[0079] The time required for the pressure in a closed chamber to rise from the initial pressure to the preset target pressure is recorded as the pressure rise time. .

[0080] The initial pressure is usually atmospheric pressure, denoted as . P 0 Preset target pressure (denoted as...) Slightly greater than the initial pressure, it can be set to... Pa represents the pressure unit Pascal, abbreviated as Pa.

[0081] Step S143: Compare the pressurization time with a preset standard time range to obtain the integrity test result of the microporous breathable membrane.

[0082] Then, the pressurization time is compared with the preset standard time range to obtain the integrity test results of the microporous breathable membrane.

[0083] If the pressurization time is within the preset standard time range, the microporous breathable membrane is deemed qualified; if the pressurization time is greater than the upper limit of the standard time range, the microporous breathable membrane is deemed blocked; if the pressurization time is less than the lower limit of the standard time range, the microporous breathable membrane is deemed damaged or the detection head seal is deemed ineffective.

[0084] In one embodiment, the preset standard time range is determined based on a standard time. For example, the preset standard time range is ±20% of the standard time. Assuming the standard time... =2.0 s, then the preset standard time range is 1.6 s to 2.4 s.

[0085] In one embodiment, the standard time is pre-calibrated based on the membrane's permeability. Specifically, the standard time is determined based on a preset volume of test gas, the permeability of the microporous membrane, the effective permeable area of ​​the microporous membrane, and the average pressure difference during the pressurization process from the initial pressure to the preset target pressure. The specific determination process can be found in the following embodiments, and will not be elaborated upon here.

[0086] The powder material packaging method provided in this application embodiment can prevent unqualified packaging bags from flowing into the subsequent packaging process by conducting online integrity detection of the microporous breathable membrane. This avoids secondary oxidation of the powder material due to damage to the microporous breathable membrane, and also avoids the problem of bag bursting / collapse due to excessive internal and external pressure difference in extreme logistics environments caused by blockage of the microporous breathable membrane.

[0087] This application provides a powder material packaging control device, which is configured to perform the following powder material packaging control method: Control the vacuum valve and the gas filling valve to perform at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged; wherein each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration in the packaging bag is obtained, and the operating parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration.

[0088] The powder material packaging control device described in the embodiments of this application and the powder material packaging control method described below can be referred to in correspondence with each other.

[0089] Figure 3 An example is a schematic diagram of the physical structure of a powder material packaging control device, such as... Figure 3 As shown, the powder material packaging control device may include: a processor 310, a communication interface 320, a memory 330, and a communication bus 340. The processor 310, communication interface 320, and memory 330 communicate with each other via the communication bus 340. The processor 310 can call logic instructions stored in the memory 330 to execute the following powder material packaging control method.

[0090] Furthermore, the logical instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the powder material packaging control method described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0091] Figure 4 This is one of the flowcharts illustrating the powder material packaging control method provided in the embodiments of this application, such as... Figure 4 As shown, the powder material packaging control method includes step S210.

[0092] Step S210: Control the vacuum valve and the gas filling valve to perform at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged; Each replacement cycle includes a vacuuming phase and a protective gas filling phase. After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

[0093] The powder material packaging control method of this application embodiment is applied to powder material packaging control equipment.

[0094] The powder material packaging control equipment is electrically connected to the vacuum valve of the vacuum pumping line and the inflation valve of the protective gas filling line. By controlling the vacuum valve and the inflation valve, the packaging bag containing the powder material to be packaged undergoes at least two vacuum-protective gas replacement cycles. Each replacement cycle consists of two sequentially executed sub-stages: (1) Vacuuming stage: Open the vacuum valve, close the inflation valve, and use the vacuum pump to extract the mixed gas in the packaging bag, so that the absolute pressure in the packaging bag is reduced to the target vacuuming pressure. (2) Protective gas filling stage: Close the vacuum valve, open the filling valve, and fill the packaging bag with protective gas through the protective gas filling pipeline to raise the absolute pressure inside the packaging bag to the target filling pressure.

[0095] It should be understood that the target vacuum pressure and target inflation pressure are different for different sequences of replacement cycles, and can be preset according to actual needs. No specific limitation is made here.

[0096] After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

[0097] In one embodiment, the powder material packaging control equipment is electrically connected to an oxygen sensor installed on a vacuum line. The oxygen sensor obtains the current actual oxygen concentration inside the packaging bag.

[0098] Furthermore, the oxygen sensor is installed on the side adjacent to the packaging bag to avoid dilution by ambient air and ensure the accuracy of the current actual oxygen concentration measurement.

[0099] In one embodiment, after the vacuuming phase of the current displacement cycle is completed (i.e., the current target vacuum pressure is reached), the vacuum valve is closed; a preset stabilization time (e.g., 3 seconds) is waited for the gas in the pipeline to diffuse evenly, and then the oxygen concentration value of the oxygen sensor is read and used as the current actual oxygen concentration. By waiting for the preset stabilization time, the accuracy of the current actual oxygen concentration measurement can be further improved.

[0100] In one embodiment, the powder material is a battery positive electrode material, and the packaging bag is an aluminum-plastic composite bag. Battery positive electrode materials are easily oxidized in air; by using an aluminum-plastic composite bag with good gas barrier properties, external oxygen and water vapor can be effectively prevented from penetrating into the bag.

[0101] Furthermore, in one embodiment, the positive electrode material of the battery is lithium iron phosphate powder, and the corresponding protective gas is nitrogen.

[0102] The powder material packaging control method provided in this application embodiment performs at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged by controlling a vacuum valve and a gas filling valve. Each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration. In this application embodiment, by performing multiple vacuum-protective gas replacement cycles and determining the operating parameters for subsequent replacement cycles based on the obtained current actual oxygen concentration during each replacement cycle, the oxygen removal effect is effectively improved by combining multiple vacuum-protective gas replacement cycles with adaptive control. This method is also compatible with packaging powder materials of different batches and packaging scenarios, avoiding insufficient oxygen removal or energy waste caused by environmental or material fluctuations.

[0103] Based on any of the above embodiments Figure 5This is the second flowchart of the powder material packaging control method provided in this application, as shown below. Figure 5 As shown, the step "determine the operating parameters of the subsequent replacement cycle based on the current actual oxygen concentration" includes steps S211 and S212.

[0104] Step S211: Obtain the current target oxygen concentration threshold corresponding to the order of the current replacement cycle.

[0105] Based on the ideal gas dilution model and production experience, a mapping relationship between the order of the displacement cycle and the current target oxygen concentration threshold is established in advance.

[0106] For example, the current target oxygen concentration threshold corresponding to the first replacement cycle. The current target oxygen concentration threshold corresponding to the second replacement cycle. The current target oxygen concentration threshold corresponding to the third replacement cycle is set to... .

[0107] Based on the order of the current permutation cycle k Obtain the corresponding current target oxygen concentration threshold from the above mapping relationship. .

[0108] Step S212: If the current actual oxygen concentration is greater than the current target oxygen concentration threshold, then adjust the operating parameters of the subsequent replacement cycle based on the current actual oxygen concentration.

[0109] Current actual oxygen concentration Compared with the current target oxygen concentration threshold Perform a comparison, if > If the current replacement effect is not as expected, it is determined based on the current actual oxygen concentration. Adjust the operating parameters for subsequent replacement cycles; if ≤ If the current displacement is satisfactory, then there is no need to adjust the operating parameters of subsequent displacement cycles; simply continue executing the displacement cycle with the default operating parameters.

[0110] Furthermore, if ≤ It can also be further... With the final target oxygen concentration The comparison was performed to determine the final target oxygen concentration. (i.e., 100 ppm). If If so, there is no need to adjust the operating parameters of subsequent replacement cycles; if If the final oxygen removal requirement is met, the replacement cycle ends. By increasing the comparison between the current actual oxygen concentration and the final target oxygen concentration, the replacement cycle can be stopped in time when the final target oxygen concentration is reached, thereby saving energy and improving packaging efficiency.

[0111] The powder material packaging control method provided in this application, in each replacement cycle, if the current actual oxygen concentration is detected to be greater than the current target oxygen concentration threshold corresponding to the current replacement cycle sequence, it is determined that the current replacement effect has not met expectations, and the operating parameters of subsequent replacement cycles are adjusted in a timely manner to ensure the final deoxygenation effect.

[0112] Based on any of the above embodiments, the operating parameters include at least one of the total number of replacement cycles, vacuuming time, and inflation pressure.

[0113] Let the first k The oxygen mole fraction in the bag before the second replacement was: Evacuate to absolute pressure (Unit: kPa) After that, the oxygen mole fraction remained unchanged, but the total pressure decreased; then nitrogen was added until the absolute pressure was reached. The oxygen mole fraction was diluted to: .

[0114] in, Indicates the first k Mole fraction of oxygen in the bag after the first replacement (dimensionless); Indicates the first k Target absolute pressure for the next vacuum pump (unit: kPa); Indicates the first k Absolute pressure inside the bag after the first nitrogen filling (unit: kPa). =Atmospheric pressure Nitrogen purging gauge pressure.

[0115] Based on the above ideal gas dilution model, the adjustable operating parameters include, but are not limited to: total number of replacement cycles, vacuuming time, and charging pressure.

[0116] The total number of permutation cycles refers to the total number of cycles from the start of the first permutation cycle to the end of the last permutation cycle under adaptive adjustment. Its initial default value can be set to 3, but it can be dynamically increased based on feedback during execution.

[0117] Vacuuming time refers to the duration during a single vacuuming phase when the vacuum pump remains operational, extracting gas from the packaging bag. Extending the vacuuming time allows for more complete extraction of gas from the bag, further reducing the amount of residual gas inside.

[0118] Inflation pressure refers to the target inflation pressure inside the packaging bag at the end of a single protective gas inflation phase. Increasing the inflation pressure allows for the inflation of a larger volume of protective gas, thereby providing a stronger dilution effect on the residual oxygen inside the bag.

[0119] The powder material packaging control method provided in this application can be adjusted to meet different needs under different circumstances through the above-mentioned multiple dimensions of operating parameters.

[0120] Based on any of the above embodiments, the current target oxygen concentration threshold includes a current oxygen concentration safety threshold and a current oxygen concentration fine-tuning threshold, wherein the current oxygen concentration safety threshold is greater than the current oxygen concentration fine-tuning threshold. Figure 6 This is the third flowchart of the powder material packaging control method provided in this application, as shown below. Figure 6 As shown, step S212 includes: step S2121 and step S2122.

[0121] Step S2121: If the current actual oxygen concentration is greater than the current oxygen concentration safety threshold, then increase the total number of replacement cycles, and / or extend the vacuuming time, and / or increase the inflation pressure.

[0122] For each replacement cycle, two thresholds are set: a safe threshold for the current oxygen concentration and a fine-tuning threshold for the current oxygen concentration. The safe threshold for the current oxygen concentration is greater than the fine-tuning threshold for the current oxygen concentration.

[0123] Among them, the current oxygen concentration safety threshold is used as the judgment line for serious deviation. Exceeding this value indicates that the current replacement effect is seriously below expectations. The current oxygen concentration fine-tuning threshold is used as the judgment line for slight deviation. Being between this value and the current oxygen concentration safety threshold indicates that the current replacement effect is slightly insufficient but not seriously deviated.

[0124] For example, the current oxygen concentration safety threshold for the first replacement cycle is set to 5%, and the current oxygen concentration fine-tuning threshold is set to 3%; the current oxygen concentration safety threshold for the second replacement cycle is set to 2%, and the current oxygen concentration fine-tuning threshold is set to 0.5%.

[0125] If the current actual oxygen concentration is greater than the current safe oxygen concentration threshold, then increase the total number of replacement cycles and / or extend the vacuuming time and / or increase the inflation pressure.

[0126] Furthermore, the specific operating parameters to be adjusted can be determined not only based on the current actual oxygen concentration, but also by considering the current order of the replacement cycle.

[0127] In one embodiment, if the current replacement cycle is the first cycle and the current actual oxygen concentration is greater than the current safe oxygen concentration threshold, then the total number of replacement cycles is increased and the vacuuming time is extended. If the current replacement cycle is the second cycle and the current actual oxygen concentration is greater than the current safe oxygen concentration threshold, then the total number of replacement cycles is increased and the inflation pressure is increased. If the current replacement cycle is the third cycle and the current actual oxygen concentration is greater than the current safe oxygen concentration threshold, then the total number of replacement cycles is increased, and the batch is marked as requiring re-inspection.

[0128] Step S2122: If the current actual oxygen concentration is less than or equal to the current oxygen concentration safety threshold and greater than the current oxygen concentration fine-tuning threshold, then increase the inflation pressure.

[0129] If the current actual oxygen concentration is less than or equal to the current oxygen concentration safety threshold, but greater than the current oxygen concentration fine-tuning threshold, then a mild intervention will be implemented, increasing only the inflation pressure. The specific increase can be determined based on the current replacement cycle.

[0130] In one embodiment, the default operating parameters are as follows: the total number of replacement cycles is 3; the inflation pressure of each protective gas filling stage is 0.08 MPa; the absolute pressure of the target vacuuming pressure in each vacuuming stage is set to increase with the increase of the replacement cycle sequence. During the first replacement, a lower vacuuming pressure of 5 kPa is used to quickly remove most of the air; during the second replacement, the vacuuming pressure is slightly increased to 8 kPa to avoid powder dust; during the third replacement, the vacuuming pressure is increased to 10 kPa.

[0131] The rules for adjusting the operating parameters are shown in the table below.

[0132] The powder material packaging control method provided in this application sets two thresholds to judge different degrees of deviation, and then adopts different operating parameter adjustment strategies, thereby maximizing the balance between equipment energy consumption, gas consumption and packaging efficiency while ensuring the oxygenation qualification rate.

[0133] Based on any of the above embodiments, the step "obtaining the current actual oxygen concentration in the packaging bag" includes: obtaining the current actual oxygen concentration of the gas extracted from the packaging bag during the vacuuming phase of the current replacement cycle by means of an oxygen sensor installed on the vacuuming pipeline and adjacent to the side of the packaging bag.

[0134] A high-precision oxygen concentration sensor (range 0-21%, accuracy ±0.1%) is installed between the vacuum line and the packaging bag. The sensor is installed on the side close to the bag. The actual oxygen concentration of the gas extracted from the packaging bag during the vacuum phase of the current replacement cycle is obtained by installing the oxygen sensor on the vacuum line and adjacent to the packaging bag.

[0135] The powder material packaging control method provided in this application obtains the current actual oxygen concentration by installing an oxygen sensor near the packaging bag, which can avoid dilution by ambient air and ensure the accuracy of the current actual oxygen concentration measurement.

[0136] Based on any of the above embodiments, the powder material packaging control method further includes steps S221 and S222.

[0137] Step S221: If the current replacement cycle order is greater than or equal to a preset order, calculate the rate of decrease of the current actual oxygen concentration relative to the previous actual oxygen concentration obtained in the previous cycle.

[0138] Because there is a large amount of residual air in the bag after the first replacement, the oxygen concentration drops significantly and follows a dilution pattern, making it difficult to determine the anomaly based on the rate of change. Therefore, in this embodiment, the preset order is set to 2, and the sealing anomaly monitoring is only activated when the order of the current replacement cycle is greater than or equal to 2.

[0139] First, calculate the rate of decrease of the current actual oxygen concentration relative to the previous actual oxygen concentration obtained in the previous sequence, specifically: ,in, Indicates the current order The current actual oxygen concentration obtained, Indicates the previous order The previous actual oxygen concentration obtained.

[0140] Step S222: If the rate of decrease is less than a preset rate of decrease threshold, it is determined to be a sealing abnormality, triggering an alarm and interrupting subsequent packaging.

[0141] If the rate of decrease is less than the preset rate of decrease threshold, it is determined to be a sealing abnormality, triggering an alarm and interrupting subsequent packaging.

[0142] In one embodiment, the preset decline rate threshold can be set to 25%-35%, for example, 30%.

[0143] In one embodiment, the alarm methods include, but are not limited to, audible alarms and flashing indicator lights, to prompt staff to inspect the packaging bags and related equipment.

[0144] The powder material packaging control method provided in this application can detect sealing abnormalities in a timely manner by continuously monitoring oxygen concentration, thereby triggering an alarm and interrupting subsequent packaging, thus avoiding the continuous production of products with excessive residual oxygen.

[0145] Based on any of the above embodiments Figure 7 This is the fourth flowchart of the powder material packaging control method provided in this application, as shown below. Figure 7 As shown, the powder material packaging control method further includes steps S231, S232, S233 and S234.

[0146] Step S231: Obtain the actual pressure according to the preset sampling period. The actual pressure includes the actual vacuum pressure or the actual inflation pressure.

[0147] When controlling the vacuum valve and the gas filling valve to perform a vacuum-protective gas replacement cycle on the packaging bag containing the powder material to be packaged, the actual pressure is obtained according to the preset sampling cycle.

[0148] Specifically, during the vacuuming phase, the actual vacuuming pressure is obtained according to a preset sampling cycle; during the protective gas filling phase, the actual filling pressure is obtained according to a preset sampling cycle.

[0149] The preset sampling period can be set to Of course, you can also set it according to your actual needs.

[0150] Step S232: Calculate the pressure deviation between the actual pressure and the target pressure, wherein the target pressure includes the target vacuum pressure or the target inflation pressure.

[0151] Calculate the pressure deviation between the actual vacuum pressure and the target vacuum pressure, denoted as the vacuum pressure deviation; calculate the pressure deviation between the actual inflation pressure and the target inflation pressure, denoted as the inflation pressure deviation. The specific calculation method is as follows: ; in, Indicates the first k Pressure deviation of each sample, in kPa; Indicates the first k The target pressure corresponding to the next sample; Indicates the first k The actual pressure obtained from the second sampling Step S233: Based on the pressure deviation, calculate the control output increment using an incremental proportional-integral-derivative control algorithm.

[0152] Based on the pressure deviation, the control output increment is calculated using an incremental PID (Proportional-Integral-Derivative) control algorithm. Correspondingly, the control output increment includes the control output increment of the vacuum valve and the control output increment of the inflation valve. The specific calculation method is as follows: ; in, Indicates the first k The incremental control output of each sample corresponds to the change in valve opening. Indicates the first Pressure deviation in the second sampling; Indicates the first Pressure deviation in the second sampling; These represent the PID parameters, namely the proportional, integral, and derivative coefficients, which can be tuned using the Ziegler-Nichols method. Typical values ​​are... , Differential coefficients .

[0153] It should be understood that when calculating the control output increment of the vacuum valve and the control output increment of the air charging valve, the proportional coefficient, integral coefficient and derivative coefficient of the two can be tuned separately using the Ziegler-Nichols method, and the same PID parameters are not used.

[0154] Step S234: Adjust the opening of the vacuum valve or the gas filling valve based on the control output increment until the pressure deviation within a preset number of consecutive sampling periods is within a preset steady-state error range.

[0155] The current valve opening is calculated based on the control output increment. The control output increment includes the control output increment of the vacuum valve and the control output increment of the charging valve; correspondingly, the current valve opening includes the current valve opening of the vacuum valve and the current valve opening of the charging valve. The specific calculation method is as follows: ; in, Indicates the first k The valve opening corresponding to each sampling is limited to between 0% and 100%. Indicates the first The valve opening corresponding to each sample.

[0156] Then, a valve opening command is sent to the vacuum valve based on the current valve opening of the vacuum valve to adjust the vacuum valve, or a valve opening command is sent to the inflation valve based on the current valve opening of the inflation valve to adjust the opening of the inflation valve. Then, the process returns to step S231 and continues to execute steps S231-S234 until the pressure deviation within a preset number of consecutive sampling periods is within a preset steady-state error range.

[0157] In one embodiment, the preset quantity can be set to 5, and the preset steady-state error range can be set to ±0.2 kPa. That is, the pressure deviation over 5 consecutive sampling periods. If the pressure is ≤±0.2kPa, it is determined that the pressure has reached a steady state. The steady-state error can be controlled within ±0.2kPa, which is more than an order of magnitude higher than the accuracy of open-loop control (which relies on experience for timing), thereby ensuring the accuracy of dilution calculation.

[0158] Furthermore, if the pressure drop rate during the vacuuming stage is too slow (e.g., it takes more than 10 seconds to reach the target), a check for sealing is prompted. If the pressure overshoot exceeds the set value by more than 10% during the protective gas charging stage, the nitrogen charging valve is immediately closed and an alarm is triggered. Through the above safety interlock mechanism, an alarm can be triggered as soon as a problem occurs, prompting staff to resolve the issue promptly and preventing safety or economic losses such as packaging bag rupture or excessive consumption of protective gas.

[0159] The powder material packaging control method provided in this application, through PID pressure closed-loop control, can automatically adjust the valve opening to compensate for fluctuations in vacuum pump performance, protective gas source pressure, etc., and ensure that the final pressure is always stable at the target pressure value.

[0160] Based on any of the above embodiments Figure 8 This is the fifth flowchart of the powder material packaging control method provided in this application, as shown below. Figure 8 As shown, after step S210, the powder material packaging control method further includes steps S241, S242 and S243.

[0161] Step S241: Obtain the final parameters when the displacement cycle is completed; the final parameters include at least the final oxygen concentration, the final vacuum pressure, and the final inflation pressure.

[0162] Obtain the final parameters when the displacement cycle is completed; the final parameters include at least the final actual oxygen concentration, the final vacuum pressure, and the final inflation pressure.

[0163] The final actual oxygen concentration is the actual oxygen concentration measured after the vacuuming stage of the last replacement cycle has stabilized; the final vacuuming pressure is the actual vacuuming pressure measured after the vacuuming stage of the last replacement cycle has stabilized; and the final charging pressure is the actual charging pressure measured after the protective gas charging stage of the last replacement cycle has stabilized.

[0164] Step S242: Input the final parameters into the oxygen concentration prediction model to obtain the final oxygen concentration prediction value inside the packaging bag after the reserved opening is closed, as output by the oxygen concentration prediction model.

[0165] The oxygen concentration prediction model is a mathematical model derived from fitting the ideal gas dilution principle with historical sampling data. It is used to predict the final residual oxygen level inside the bag without damaging the packaging. Details are as follows: ; in, This represents the predicted final oxygen concentration. This indicates the final actual oxygen concentration; Indicates the final inflation pressure; Indicates the final vacuum pressure; This represents atmospheric pressure, which is 101.3 kPa.

[0166] For example, suppose ,but 0.008×0.154=0.00123%=12.3 ppm.

[0167] For example, suppose ,but ppm.

[0168] Step S243: Based on the predicted final oxygen concentration, classify the quality of the currently packaged product.

[0169] The final predicted oxygen concentration is compared with the preset quality threshold, and the quality of the currently packaged product is graded based on the comparison results.

[0170] In one embodiment, a first preset quality threshold and a second preset quality threshold are set, wherein the first preset quality threshold is less than the second preset quality threshold. The first preset quality threshold can be set to 100 ppm, and the second quality threshold can be set to 200 ppm. If the predicted final oxygen concentration is <100 ppm, the corresponding quality level is Grade A; if 100 ppm < predicted final oxygen concentration ≤ 200 ppm, the corresponding quality level is Grade B; if the predicted final oxygen concentration is >200 ppm, the corresponding quality level is Grade C. The quality levels are ranked as follows: Grade A > Grade B > Grade C. Different quality levels can be used for different purposes.

[0171] Furthermore, the final parameters at the completion of the displacement cycle, the actual operating parameters during the displacement cycle, the final oxygen concentration prediction value, and the quality grade can be associated and stored with the finished product number of the powder material packaging to facilitate subsequent quality traceability.

[0172] The powder material packaging control method provided in this application uses an oxygen concentration prediction model to predict the final oxygen concentration value, which avoids the damage to the packaging caused by traditional needle-punch sampling inspection with residual oxygen meters. At the same time, it achieves objective quality grading based on the final oxygen concentration prediction value for different uses, thereby improving the overall utilization rate of the product.

[0173] Based on any of the above embodiments, the packaging bag is provided with a microporous breathable membrane.

[0174] Considering that changes in ambient temperature or atmospheric pressure cause the gas inside the bag to expand and contract, leading to bulging (easily damaged) or denting (air intake) and secondary oxidation, traditional packaging bags lack pressure balancing design, resulting in poor sealing reliability. Therefore, in this embodiment, a microporous breathable membrane is provided on the pre-packaged bag. The inner side of this microporous breathable membrane communicates with the inner cavity of the packaging bag, while the outer side communicates with the external atmosphere. This allows the packaging bag to maintain a bidirectional gas balance channel even after sealing, thereby solving the problem of bag bursting / collapse caused by excessive internal and external pressure differences under extreme logistics environments without significantly disrupting the low-oxygen environment inside the bag. This improves the adaptability of powder material packaging for finished product transportation.

[0175] In one embodiment, a microporous breathable membrane is embedded in the body of the packaging bag beforehand during the empty bag manufacturing stage by means of hot melt bonding or adhesive bonding process.

[0176] In one embodiment, the microporous breathable membrane is disposed at the reserved edge of the upper side or top of the packaging bag. Specifically, for vertically sealed packaging bags, the microporous breathable membrane is preferably disposed at the top of the bag, for example, in the area 5cm-10cm below the heat-sealed edge of the bag opening; for packaging bags transported horizontally, the microporous breathable membrane is preferably disposed at the upper side of the bag so that the membrane surface remains facing upward when the bag is tilted or turned over, avoiding direct coverage of powder.

[0177] It should be noted that because powder materials such as lithium iron phosphate are extremely fluid and fine, if the microporous breathable membrane is placed at the bottom or lower part of the packaging bag, the powder can easily physically bury and block the micropores under the heavy pressure of stacking during transportation, rendering the membrane unable to allow air to pass through. Placing the microporous breathable membrane at the reserved edge on the upper side or top ensures that it can work effectively under various transportation conditions.

[0178] Based on any of the above embodiments, the microporous breathable membrane is made of polytetrafluoroethylene or polypropylene, the pore size of the microporous breathable membrane is 0.1 μm-0.5 μm, and the oxygen permeability of the microporous breathable membrane is not greater than 0.5 cm. 3 / (m 2 ·24h·atm).

[0179] The microporous breathable membrane is made of polytetrafluoroethylene (PTFE) or polypropylene (PP), both of which have excellent hydrophobicity and chemical stability.

[0180] The microporous breathable membrane has a pore size of 0.1 μm-0.5 μm. This pore size range can block liquid water penetration and lithium iron phosphate powder leakage, while ensuring gas passage.

[0181] The oxygen transmission rate (OTR) of the microporous breathable membrane is no greater than 0.5 cm. 3 / (m 2 The test method is based on ASTM D3985 standard (24h·atm). Under this OTR parameter, it is extremely difficult for oxygen from the external environment to penetrate into the packaging bag, which can effectively prevent secondary oxidation of powder materials during transportation and storage.

[0182] Based on any of the above embodiments, the powder material packaging control method further includes steps S251 and S252.

[0183] Step S251: Obtain the internal volume of the packaging bag, the safety differential pressure threshold, and the expected rate of change of external environmental pressure.

[0184] Obtain the internal volume of the packaging bag, denoted as . V .

[0185] The safe differential pressure threshold is preset and denoted as . It can be set to 1 kPa.

[0186] The expected rate of change of external environmental pressure is denoted as . This refers to the rate of change of external environmental pressure, obtained from meteorological databases or on-site measurements, based on the expected transportation environment (such as transportation mode, altitude variation range, temperature variation range, etc.). This indicator is used to characterize the severity of transportation operating conditions.

[0187] Step S252: Input the internal volume, the safe pressure difference threshold, and the expected rate of change of external environmental pressure into the system pressure difference balance dynamic model to solve for the effective air permeable area and air permeability that make the maximum pressure difference between the inside and outside of the packaging bag less than or equal to the safe pressure difference threshold.

[0188] The internal volume, the safe differential pressure threshold, and the expected rate of change of external environmental pressure are input into the dynamic model of system differential pressure balance.

[0189] In one implementation, the dynamic model of the system pressure balance is constructed based on the following ordinary differential equation: ; in, Indicates the pressure inside the packaging bag Over time t The rate of change; Indicates the pressure inside the packaging bag; Indicates external environmental pressure; This represents the system time constant, which is determined as follows: .

[0190] in, The internal volume of the packaging bag is represented by A, the effective air permeable area of ​​the microporous breathable membrane is represented by Q, and the air permeability of the microporous breathable membrane is represented by Q.

[0191] In the dynamic model of pressure balance in this system, the external environmental pressure is expressed as: ,in, Representing the initial external environmental pressure, solving the above ordinary differential equation yields the result at any time... t internal pressure of the bag and maximum pressure difference .

[0192] Based on the packaging bag volume V and the expected rate of environmental change Consult the table to select the breathable membrane model to obtain the effective breathable area. A and breathability Q By adjusting the effective air permeable area A and breathability Q Determine the maximum pressure difference Is it less than or equal to the safe differential pressure threshold? ,like ≤ The effective air permeable area of ​​the current combination A and breathability Q feasible.

[0193] For example, suppose , , , ,but Seconds. In the event of a sudden temperature change, the pressure inside the bladder will balance to near atmospheric pressure within about 1 minute, with the maximum pressure difference controllable within 0.5 kPa.

[0194] The powder material packaging control method provided in this application determines the effective air permeability area and air permeability of the microporous breathable membrane through a system pressure difference balance dynamic model, which is more scientific than the traditional experience-based selection method.

[0195] Based on any of the above embodiments, the powder material packaging control method further includes steps S261 and S262.

[0196] Step S261: Obtain the pressure rise time required for the pressure in the sealed chamber to rise from the initial pressure to the preset target pressure after a preset volume of test gas is injected; the sealed chamber is formed on the outside of the microporous breathable membrane by covering the microporous breathable membrane with a detection head with a sealing ring.

[0197] After the microporous breathable membrane is placed on the packaging bag, a special detection head with a sealing ring is used to cover the area of ​​the microporous breathable membrane to form a closed chamber on the outside of the microporous breathable membrane. Then, a preset volume of test gas is injected into the closed chamber using a syringe or a precision air pump.

[0198] In one embodiment, a preset volume The volume is 3mL-7mL, for example, 5mL.

[0199] In one embodiment, the test gas is air.

[0200] Obtain the pressure within the closed chamber from the initial pressure P 0 Rise to the preset target pressure Required boost time The initial pressure is typically atmospheric pressure; the target pressure (denoted as ) is slightly greater than the initial pressure and can be set to . Pa represents the pressure unit Pascal, abbreviated as Pa.

[0201] Step S262: Compare the pressurization time with a preset standard time range to obtain the integrity test result of the microporous breathable membrane.

[0202] Then, the pressurization time is compared with the preset standard time range to obtain the integrity test results of the microporous breathable membrane.

[0203] The powder material packaging control method provided in this application can prevent unqualified packaging bags from flowing into the subsequent packaging process by conducting online detection of the integrity of the microporous breathable membrane.

[0204] Based on any of the above embodiments, step S262 includes: step S2621, step S2622 and step S2623.

[0205] Step S2621: If the pressurization time is within the preset standard time range, the microporous breathable membrane is determined to be qualified.

[0206] In one embodiment, the preset standard time range is determined based on a standard time. For example, the preset standard time range is ±20% of the standard time. Assuming the standard time... =2.0 s, then the preset standard time range is 1.6 s to 2.4 s.

[0207] Taking a preset standard time range of 1.6 s to 2.4 s as an example, if the boost time... If the time is between 1.6 s and 2.4 s, the microporous breathable membrane is deemed qualified.

[0208] Step S2622: If the pressurization time is greater than the upper limit of the standard time range, then the microporous breathable membrane is determined to be blocked.

[0209] Taking a preset standard time range of 1.6 s to 2.4 s as an example, if the boost time... If the time is greater than 2.4 s, it indicates that the gas in the closed chamber is extremely difficult to pass through the microporous breathable membrane into the packaging bag, resulting in pressure buildup, and the microporous breathable membrane is therefore determined to be blocked.

[0210] Step S2623: If the pressurization time is less than the lower limit of the standard time range, it is determined that the microporous breathable membrane is damaged or the detection head seal is ineffective.

[0211] Taking a preset standard time range of 1.6 s to 2.4 s as an example, if the boost time... If the time is less than 1.6 s, it indicates that the gas has leaked into the bag or to the outside with almost no resistance. This indicates that the microporous breathable membrane is damaged or the detection head seal is ineffective, and triggers the corresponding alarm.

[0212] The powder material packaging control method provided in this application compares the pressurization time with a preset standard time range to determine whether the microporous breathable membrane is intact. This avoids secondary oxidation of the powder material due to damage to the microporous breathable membrane, and also avoids the problem of bag bursting / collapse caused by excessive internal and external pressure difference in extreme logistics environments due to blockage of the microporous breathable membrane.

[0213] Based on any of the above embodiments, the standard time is determined based on the preset volume of the test gas, the permeability of the microporous breathable membrane, the effective permeable area of ​​the microporous breathable membrane, and the average pressure difference during the pressurization process from the initial pressure to the preset target pressure.

[0214] In this embodiment, the standard time is pre-calibrated based on the membrane's permeability. Specifically, the standard time is determined based on the preset volume of the test gas, the permeability of the microporous membrane, the effective permeable area of ​​the microporous membrane, and the average pressure difference during the pressurization process from the initial pressure to the preset target pressure. The specific calculation method is as follows: ; in, This represents the average pressure difference during the pressurization process from the initial pressure to the preset target pressure, which is approximately 25 Pa.

[0215] In one embodiment, the standard time corresponding to different parameters can be pre-calculated and stored in a table, which can be directly looked up in the table for later use.

[0216] The powder material packaging control method provided in this application can automatically generate a new standard time by simply substituting the new parameters into the formula when changing packaging bags of different sizes or microporous breathable membranes of different areas and air permeability. This is more accurate and reliable than setting the standard time based on empirical values.

[0217] Furthermore, to illustrate the effects of the embodiments of this application, the following embodiments and comparative examples are provided.

[0218] The initial conditions for each embodiment and comparative example were as follows: 25 kg of lithium iron phosphate powder material after sieving and iron removal treatment, ambient temperature of 25°C, atmospheric pressure of 101.3 kPa, and initial oxygen concentration in the bag air of 21%.

[0219] The default operating parameters for each embodiment are: total number of permutation cycles. The process is repeated 3 times. The absolute pressure of the target vacuum pressure in each vacuum stage is set to increase with the increase of the replacement cycle. In the first replacement, a lower vacuum pressure of 5 kPa is used; in the second replacement, the vacuum pressure is slightly increased to 8 kPa; and in the third replacement, the vacuum pressure is increased to 10 kPa.

[0220] Example 1 (Standard Operating Conditions) In this embodiment, the default operating parameters are set as follows: nitrogen pressure during the protective gas filling stage is 0.08 MPa for the first replacement; nitrogen pressure during the second replacement; and nitrogen pressure during the third replacement.

[0221] (1) Packing and pre-sealing: The lithium iron phosphate powder material after screening and iron removal is packed into aluminum-plastic composite bags according to the nominal weight (25 kg), and the three sides of the bag are heat-sealed, leaving one side open for later use.

[0222] (2) Adaptive vacuum-nitrogen replacement cycle: ①The first replacement process is as follows: set up Turn on the vacuum pump and use PID control for the vacuum valve.

[0223] The pressure dropped from 101.3 kPa to 5 kPa in approximately 8 seconds, stabilized for 3 seconds, and then the oxygen concentration was read. because This triggers an increase in the total number of replacement cycles. Increase from 3 to 4, and extend the first vacuuming time by 10 seconds (the actual vacuuming time becomes 18 seconds).

[0224] The nitrogen filling valve pressure is set to 0.08 MPa (absolute pressure 181.3 kPa). The nitrogen filling valve is controlled by PID. It takes about 5 seconds for the pressure to rise from 5 kPa to 181.3 kPa and then hold the pressure for 10 seconds.

[0225] ②The second permutation process is as follows: set up The vacuuming process takes approximately 6 seconds, followed by 3 seconds of stabilization, and then the oxygen concentration is read. because This triggers an increase in the total number of replacement cycles. Increase to 5, and set the third nitrogen filling pressure to 0.12 MPa (gauge pressure).

[0226] The nitrogen filling valve pressure is set to 0.08 MPa (absolute pressure 181.3 kPa), and the nitrogen filling valve is controlled by PID.

[0227] ③The third permutation process is as follows: set up The vacuuming process takes approximately 5 seconds, followed by 3 seconds of stabilization, and then the oxygen concentration is read. because Continuing with the fourth replacement, due to Since it's already at 5, it will continue. No adjustments will be made here, and the fourth nitrogen filling pressure will still be set to a high pressure of 0.12 MPa (gauge pressure).

[0228] Set the nitrogen charging valve pressure to high pressure, with a gauge pressure of 0.12 MPa (absolute pressure 221.3 kPa), and use PID control for the nitrogen charging valve.

[0229] ④ The fourth permutation process is as follows: Evacuate to 10 kPa, stabilize for 3 seconds, and read the oxygen concentration. (1200 ppm).

[0230] Still above the target of 100 ppm, the fifth replacement was continued.

[0231] Set the nitrogen charging valve pressure to high pressure, with a gauge pressure of 0.12 MPa (absolute pressure 221.3 kPa), and use PID control for the nitrogen charging valve.

[0232] ⑤ The fifth permutation process is as follows: Evacuate to 10 kPa, stabilize for 3 seconds, and read the oxygen concentration. Still above the target of 100 ppm, the sixth replacement was carried out.

[0233] Set the nitrogen charging valve pressure to high pressure, with a gauge pressure of 0.12 MPa (absolute pressure 221.3 kPa), and use PID control for the nitrogen charging valve.

[0234] ⑤ The sixth permutation process is as follows: Evacuate to 10 kPa, stabilize for 3 seconds, and read the oxygen concentration. If the nitrogen concentration is not higher than the target of 100 ppm, set the nitrogen purging valve pressure to 0.12 MPa (absolute pressure 221.3 kPa). After completing the nitrogen purging, stop the purging process.

[0235] (3) Heat sealing. The heat sealing process is as follows: after the sixth nitrogen filling, maintain a slight positive pressure of 0.015 MPa and heat seal the opening reserved in the packaging bag.

[0236] Example 2 In this embodiment, the default operating parameters are set as follows: 0.10 MPa for the first nitrogen charge, 0.12 MPa for the second charge, and 0.12 MPa for the third charge. The main difference between this embodiment 2 and embodiment 1 is: During the first replacement process, a vacuum was drawn to 5 kPa, and the oxygen concentration was... 18%, nitrogen filling at 0.10 MPa (absolute pressure 201.3 kPa).

[0237] During the second replacement process, a vacuum was drawn to 8 kPa, and the oxygen concentration was... 1.2% (due to the high initial nitrogen pressure, resulting in good dilution), nitrogen pressure 0.12 MPa.

[0238] During the third replacement process, the vacuum was evacuated to 10 kPa, the oxygen concentration was 0.045% (450 ppm), and the nitrogen was purged at 0.12 MPa.

[0239] After three replacement cycles, the oxygen concentration was 450 ppm, which is slightly higher than 100 ppm, but can be reduced to below 0.01% by adding one more replacement cycle.

[0240] Therefore, a fourth replacement process was added: evacuation to 10 kPa, nitrogen purging at 0.12 MPa, and oxygen concentration of 0.008% (80 ppm) were achieved, meeting the standard. The final number of replacements was 4.

[0241] Then, heat sealing is performed. The heat sealing process is as follows: after the fourth nitrogen filling, maintain a slight positive pressure of 0.015 MPa and heat seal the opening reserved in the packaging bag.

[0242] The packaging bag features a microporous breathable membrane with the following parameters: material is PTFE, pore size is 0.2μm, and air permeability is 40 L / (m²). 2 (·s·kPa), effective air permeability area is 2cm² 2 .

[0243] The final actual oxygen concentration after the last replacement , The final predicted oxygen concentration value 0.008 × 0.154 = 0.00123% = 12.3 ppm. The capacity retention rate is 99.5% after 6 months of storage.

[0244] Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that Comparative Example 1 involves a single replacement without adaptive adjustment.

[0245] That is, the vacuum was first drawn to 10 kPa, and then nitrogen was filled at 0.08 MPa. The oxygen concentration inside the bag was measured to be 2800 ppm. After 6 months of storage, the capacity retention rate was 95.1%.

[0246] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that: three replacements were performed but no adaptive adjustment was made.

[0247] The fixed parameters used for the three replacements are as follows: In the first replacement, the vacuum was reduced to 5 kPa and nitrogen was filled at 0.08 MPa; in the second replacement, the vacuum was reduced to 8 kPa and nitrogen was filled at 0.08 MPa; in the third replacement, the vacuum was reduced to 10 kPa and nitrogen was filled at 0.08 MPa. The measured oxygen concentration inside the bag was 850 ppm, which is still higher than 100 ppm.

[0248] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that the packaging bag does not have a microporous breathable membrane.

[0249] After being stored at 40℃ for 2 days, the bag bulged significantly, with slight leakage at the seal, and the oxygen concentration rose to 1200ppm.

[0250] The powder material packaging system provided in the embodiments of this application is described below.

[0251] This application provides a powder material packaging system, which includes a packaging cavity, a vacuum pipeline, a protective gas filling pipeline, an oxygen sensor, and the powder material packaging control equipment as described above; wherein, The packaging cavity is used to accommodate a pre-sealed packaging bag containing powder material to be packaged and with an opening. The vacuuming pipeline and the protective gas filling pipeline are respectively connected to the opening of the packaging bag through a vacuum valve and a gas filling valve, and are used to perform vacuum-protective gas replacement cycle on the packaging bag; The oxygen sensor is used to obtain the current actual oxygen concentration inside the packaging bag; The powder material packaging control equipment is electrically connected to the oxygen sensor, the vacuum valve, and the inflation valve, respectively.

[0252] In this embodiment, the powder material packaging system includes a packaging cavity, a vacuum pipeline, a protective gas filling pipeline, an oxygen sensor, and a powder material packaging control device. The powder material packaging control device is electrically connected to the oxygen sensor, a vacuum valve, and a filling valve. By controlling the vacuum valve and the filling valve, the packaging bag containing the powder material to be packaged in the packaging cavity undergoes at least two vacuum-protective gas replacement cycles. Each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained through the oxygen sensor, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration. Through the above packaging system, intelligent packaging of powder materials can be achieved. During the packaging process, the oxygen removal effect is effectively improved by combining multiple vacuum-protective gas replacement cycles with adaptive control. At the same time, it is compatible with the packaging of powder materials in different batches and packaging scenarios, avoiding insufficient oxygen removal or energy waste caused by environmental or material fluctuations.

[0253] Furthermore, the powder material packaging system may also include a heat sealing mechanism. The powder material packaging control equipment is electrically connected to the heat sealing mechanism and sends a heat sealing command to the heat sealing mechanism to control the heat sealing mechanism to heat seal the opening reserved in the packaging bag.

[0254] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0255] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of software products. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0256] Finally, it should be noted that the above embodiments are only used to illustrate this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application and should be covered within the scope of the claims of this application.

Claims

1. A finished product packaging for powder materials, characterized in that, The finished powder material is obtained by packaging it using the following powder material packaging method: The powder material to be packaged is placed into a packaging bag, and the packaging bag is pre-sealed, leaving an opening. The packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening; wherein each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration. After the final protective gas filling stage is completed, the reserved opening is sealed.

2. The finished product of the powder material packaging according to claim 1, characterized in that, The absolute pressure of the target vacuum pressure in each vacuuming stage is set to increase progressively with the increase of the order of the displacement cycle.

3. The finished product of the powder material packaging according to claim 1, characterized in that, After the final protective gas filling stage is completed, sealing the reserved opening includes: After the final protective gas filling stage is completed, the pressure inside the packaging bag is controlled to a slightly positive pressure state higher than the external atmospheric pressure, and the reserved opening is closed under this slightly positive pressure state.

4. The finished product of powder material packaging according to any one of claims 1 to 3, characterized in that, The packaging bag is provided with a microporous breathable membrane.

5. The finished product of the powder material packaging according to claim 4, characterized in that, The microporous breathable membrane is made of polytetrafluoroethylene or polypropylene, with a pore size of 0.1 μm-0.5 μm and an oxygen permeability of no more than 0.5 cm. 3 / (m 2 ·24h·atm).

6. The finished product of the powder material packaging according to claim 4, characterized in that, The powder material packaging method further includes: A preset volume of test gas is injected into a closed chamber, which is formed on the outside of the microporous breathable membrane by covering the microporous breathable membrane with a detection head equipped with a sealing ring. The pressure rise time required for the pressure inside the sealed chamber to rise from the initial pressure to the preset target pressure is obtained; The pressurization time is compared with a preset standard time range to obtain the integrity test result of the microporous breathable membrane.

7. The finished product of powder material packaging according to any one of claims 1 to 3, characterized in that, The powder material is a battery positive electrode material, and the packaging bag is an aluminum-plastic composite bag.

8. The finished product of the powder material packaging according to claim 7, characterized in that, The positive electrode material of the battery is lithium iron phosphate powder, and the protective gas is nitrogen.

9. A method for packaging powder materials, characterized in that, include: The powder material to be packaged is placed into a packaging bag, and the packaging bag is pre-sealed, leaving an opening. The packaging bag is subjected to at least two vacuum-protective gas replacement cycles through the opening; wherein each replacement cycle includes a vacuuming stage and a protective gas filling stage. After the vacuuming stage of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters of the subsequent replacement cycle are determined based on the current actual oxygen concentration. After the final protective gas filling stage is completed, the reserved opening is sealed.

10. A powder material packaging control device, characterized in that, The powder material packaging control equipment is configured to perform the following steps: Control the vacuum valve and the gas filling valve to perform at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged; Each replacement cycle includes a vacuuming phase and a protective gas filling phase. After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

11. The powder material packaging control equipment according to claim 10, characterized in that, The process of determining the operating parameters for subsequent replacement cycles based on the current actual oxygen concentration includes: Obtain the current target oxygen concentration threshold corresponding to the order of the current replacement cycle; If the current actual oxygen concentration is greater than the current target oxygen concentration threshold, then the operating parameters of subsequent replacement cycles are adjusted based on the current actual oxygen concentration.

12. The powder material packaging control equipment according to claim 11, characterized in that, The operating parameters include at least one of the following: total number of replacement cycles, vacuuming time, and inflation pressure.

13. The powder material packaging control equipment according to claim 12, characterized in that, The current target oxygen concentration threshold includes a current oxygen concentration safety threshold and a current oxygen concentration fine-tuning threshold, wherein the current oxygen concentration safety threshold is greater than the current oxygen concentration fine-tuning threshold. If the current actual oxygen concentration is greater than the current target oxygen concentration threshold, then based on the current actual oxygen concentration, the operating parameters of subsequent replacement cycles are adjusted, including: If the current actual oxygen concentration is greater than the current oxygen concentration safety threshold, then the total number of replacement cycles is increased, and / or the vacuuming time is extended, and / or the inflation pressure is increased; If the current actual oxygen concentration is less than or equal to the current oxygen concentration safety threshold, but greater than the current oxygen concentration fine-tuning threshold, then the inflation pressure is increased.

14. The powder material packaging control equipment according to claim 10, characterized in that, The step of obtaining the current actual oxygen concentration inside the packaging bag includes: The current actual oxygen concentration of the gas extracted from the packaging bag during the vacuuming phase of the current replacement cycle is obtained by using an oxygen sensor installed on the vacuum line and adjacent to the packaging bag.

15. The powder material packaging control equipment according to claim 10, characterized in that, The powder material packaging control equipment is also configured to: If the current replacement cycle order is greater than or equal to the preset order, calculate the rate of decrease of the current actual oxygen concentration relative to the previous actual oxygen concentration obtained in the previous cycle. If the rate of decrease is less than a preset rate of decrease threshold, it is determined to be a sealing abnormality, triggering an alarm and interrupting subsequent packaging.

16. The powder material packaging control equipment according to claim 10, characterized in that, The powder material packaging control equipment is also configured to: The actual pressure is obtained according to a preset sampling period, and the actual pressure includes the actual vacuum pressure or the actual inflation pressure. Calculate the pressure deviation between the actual pressure and the target pressure, where the target pressure includes the target vacuum pressure or the target inflation pressure; Based on the pressure deviation, the incremental control output increment is calculated using an incremental proportional-integral-derivative control algorithm. The opening of the vacuum valve or the inflation valve is adjusted incrementally based on the control output until the pressure deviation within a preset number of consecutive sampling periods is within a preset steady-state error range.

17. The powder material packaging control device according to any one of claims 10 to 16, characterized in that, The powder material packaging control equipment is also configured to: Obtain the final parameters when the displacement cycle is completed; the final parameters include at least the final actual oxygen concentration, the final vacuum pressure, and the final inflation pressure. The final parameters are input into the oxygen concentration prediction model to obtain the final oxygen concentration prediction value inside the packaging bag after the reserved opening is closed, as output by the oxygen concentration prediction model. Based on the predicted final oxygen concentration, the quality of the currently packaged products is graded.

18. The powder material packaging control equipment according to any one of claims 10 to 16, characterized in that, The packaging bag is provided with a microporous breathable membrane, which is made of polytetrafluoroethylene or polypropylene, has a pore size of 0.1 μm-0.5 μm, and an oxygen permeability of no more than 0.5 cm. 3 / (m 2 ·24h·atm).

19. The powder material packaging control equipment according to claim 18, characterized in that, The powder material packaging control equipment is also configured to: The internal volume of the packaging bag, the safety differential pressure threshold, and the expected rate of change of external environmental pressure are obtained. The internal volume, the safe pressure difference threshold, and the expected rate of change of external environmental pressure are input into the system pressure difference balance dynamic model to solve for the effective air permeable area and air permeability that make the maximum pressure difference between the inside and outside of the packaging bag less than or equal to the safe pressure difference threshold.

20. The powder material packaging control equipment according to claim 19, characterized in that, The dynamic model of the system pressure balance is constructed based on the following ordinary differential equation: ； in, Indicates the pressure inside the packaging bag Over time t rate of change, This indicates the pressure inside the packaging bag. Indicates external environmental pressure. Represents the system time constant; The system time constant is determined in the following way: ； in, The internal volume of the packaging bag is represented by A, the effective air permeable area of ​​the microporous breathable membrane is represented by Q, and the air permeability of the microporous breathable membrane is represented by Q.

21. The powder material packaging control equipment according to claim 18, characterized in that, The powder material packaging control equipment is also configured to: The pressure rise time required for the pressure in the sealed chamber to rise from the initial pressure to the preset target pressure after a preset volume of test gas is injected is obtained; the sealed chamber is formed on the outside of the microporous breathable membrane by covering the microporous breathable membrane with a detection head with a sealing ring. The pressurization time is compared with a preset standard time range to obtain the integrity test result of the microporous breathable membrane.

22. The powder material packaging control equipment according to claim 21, characterized in that, The step of comparing the pressurization time with a preset standard time range to obtain the integrity test result of the microporous breathable membrane includes: If the pressurization time is within the preset standard time range, the microporous breathable membrane is deemed qualified. If the pressurization time is greater than the upper limit of the standard time range, the microporous breathable membrane is determined to be blocked. If the pressurization time is less than the lower limit of the standard time range, it is determined that the microporous breathable membrane is damaged or the detection head seal is ineffective.

23. The powder material packaging control equipment according to claim 21, characterized in that, The preset standard time range is determined based on a standard time, which is determined based on the preset volume of the test gas, the permeability of the microporous breathable membrane, the effective permeable area of ​​the microporous breathable membrane, and the average pressure difference during the pressurization process from the initial pressure to the preset target pressure.

24. A method for controlling the packaging of powder materials, characterized in that, include: Control the vacuum valve and the gas filling valve to perform at least two vacuum-protective gas replacement cycles on the packaging bag containing the powder material to be packaged; Each replacement cycle includes a vacuuming phase and a protective gas filling phase. After the vacuuming phase of the current replacement cycle is completed, the current actual oxygen concentration inside the packaging bag is obtained, and the operating parameters for subsequent replacement cycles are determined based on the current actual oxygen concentration.

25. A powder material packaging system, characterized in that, It includes a packaging cavity, a vacuum pipeline, a protective gas filling pipeline, an oxygen sensor, and a powder material packaging control device as described in any one of claims 10 to 23; wherein, The packaging cavity is used to accommodate a pre-sealed packaging bag containing powder material to be packaged and with an opening. The vacuuming pipeline and the protective gas filling pipeline are respectively connected to the opening of the packaging bag through a vacuum valve and a gas filling valve, and are used to perform vacuum-protective gas replacement cycle on the packaging bag; The oxygen sensor is used to obtain the current actual oxygen concentration inside the packaging bag; The powder material packaging control equipment is electrically connected to the oxygen sensor, the vacuum valve, and the inflation valve, respectively.

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