Breathable film waterproof detection method and system based on dynamic differential pressure scanning

Abstract

The invention provides a waterproof detection method and system for a breathable film based on dynamic differential pressure scanning, and relates to the technical field of waterproof detection.The method comprises the steps that type data of the breathable film are collected, a waterproof test method is determined, and pressure detection is conducted on the two sides of the breathable film according to the waterproof test method to obtain pressure data. The pressure data are preprocessed to obtain pressure processing data, and feature evaluation indexes are extracted from the pressure data in combination with the membrane pore structure features and the surface processing state; establishing a characteristic index judgment standard, judging whether the characteristic judgment index reaches the characteristic index judgment standard or not, and if yes, judging that the waterproof performance of the current breathable film is qualified. Otherwise, judging that the waterproof performance of the current breathable film is unqualified, analyzing the current characteristic evaluation index to obtain a leakage reason, and feeding back to a production link optimization process. The waterproof detection device has the beneficial effects of high-precision detection, high reliability, high-efficiency detection and detailed leakage reason analysis, and the waterproof detection performance and practicability of the breathable film are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of waterproof testing technology, and in particular to a method and system for testing the waterproofness of breathable membranes based on dynamic differential pressure scanning. Background Technology

[0002] Breathable membranes, as key materials combining waterproofing and breathability, are widely used in outdoor clothing, medical protective equipment, electronic devices, and automotive parts. Their waterproof performance directly determines the safety and reliability of end products. As downstream applications increasingly demand higher performance from breathable membranes, traditional waterproofing testing methods are struggling to meet the requirements for high precision and interference resistance, gradually revealing two core technological shortcomings that have become critical bottlenecks restricting the industry's development.

[0003] Current technologies largely rely on the "static pressure holding method" or the "single pressure threshold method" to evaluate waterproof performance. The former judges compliance by monitoring whether the pressure decay under a fixed pressure exceeds a threshold, and can only identify obvious leaks with a leakage rate >0.5 mL / h, failing to capture the gradual process of minute leaks (such as 0.1-0.2 mL / h). The latter uses only the maximum pressure resistance as the criterion, ignoring the risk of slow leakage caused by the minute enlargement of membrane pores and the slow failure of the surface treatment layer during continuous use. In high-precision scenarios such as medical protection and electronic equipment, minute leaks can accumulate over time and lead to serious consequences.

[0004] On the other hand, the surface treatment of the breathable membrane, such as hydrophobic / hydrophilic modification and anti-oil coating, as well as the temperature and humidity fluctuations and installation errors in the testing environment, can all significantly interfere with the pressure signal. For example, hydrophilic modified membranes are prone to "false pressure rise" due to water vapor condensation in high humidity environments, which may be misjudged as no leakage. Local wear of the anti-oil coating can cause high-frequency fluctuations in the pressure difference, which may be misjudged as minor leakage. Uneven clamp pressure during installation can lead to poor edge sealing, which may cause "false pressure attenuation" and mask the true performance of the membrane itself.

[0005] In addition, traditional testing methods also have additional drawbacks such as "poor scene adaptability" and "ambiguous location of leakage causes": the former uses fixed testing parameters, which are out of touch with actual working conditions such as rain impact in outdoor scenes and dry environment in electronic scenes; the latter can only output "qualified / unqualified" results, and cannot distinguish whether the leakage is caused by defects in the membrane body, failure of surface treatment or external interference, making it difficult to optimize the process in the production process, and can only improve the pass rate by reworking the whole process, resulting in a lot of waste of resources.

[0006] Therefore, the industry urgently needs a test method and system for waterproof breathable membranes based on dynamic differential pressure scanning to solve the technical bottlenecks of traditional methods, meet the high-precision and high-reliability testing requirements of downstream applications for the waterproof performance of breathable membranes, and promote the quality upgrade and technological progress of the breathable membrane industry. Summary of the Invention

[0007] This invention provides a method and system for detecting waterproof breathable membranes based on dynamic differential pressure scanning, which solves the shortcomings of existing technologies in terms of insufficient accuracy in detecting minute leaks and inability to eliminate interference factors in the detection process.

[0008] On one hand, the present invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning, comprising: Collect data on the type of breathable membrane, determine the waterproof test method based on the usage scenario of the breathable membrane, and obtain pressure data by performing pressure tests on both sides of the breathable membrane according to the waterproof test method.

[0009] Pressure data is preprocessed to obtain pressure treatment data. Feature evaluation indicators are extracted from the pressure data by combining the membrane pore structure characteristics and surface treatment status and using feature fusion method.

[0010] Establish characteristic indicator judgment criteria based on type data and usage scenarios, and determine whether the characteristic evaluation indicators meet the characteristic indicator judgment criteria. If so, the current waterproof performance of the breathable membrane is deemed qualified.

[0011] Otherwise, the current breathable membrane is deemed to have unqualified waterproof performance. The current characteristic evaluation indicators are analyzed to find the cause of leakage, and the feedback is sent to the production process to optimize the process.

[0012] This invention provides a method for testing the waterproofness of breathable membranes based on dynamic differential pressure scanning. The steps for determining the waterproofness test method include: Based on the environmental pressure, contact media, and performance failure risks of the breathable membrane during application, the requirements of the usage scenario are transformed into waterproof testing targets.

[0013] A waterproof testing method is formed by combining waterproof testing targets with type data and mapping parameters such as pressure, testing cycle, test medium, and chamber environment control.

[0014] This invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning. The steps for obtaining pressure data include: Based on waterproof testing methods, a pressure testing device was constructed, comprising sealing tests, pressure control, differential pressure sensing, data acquisition, and environmental control.

[0015] The surface tension of the breathable membrane sample to be tested was pretreated to remove excess surface tension, and then positioned and fixed. The verification pressure was set according to the waterproof test method, and the sealing performance of the pressure testing device was verified.

[0016] The pressure testing device, verified according to the applied pressure, was used to test the breathable membrane sample to be tested, and pressure data on both sides were collected at different stages.

[0017] This invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning. The steps for obtaining pressure processing data include: Based on pressure control, the pressure data is divided into nodes, and the pressure data within the stable range is extracted as the data to be processed.

[0018] Select an outlier identification method based on the data type, mark outliers from the data to be processed, and replace outliers using the adjacent data moving average method.

[0019] The smoothing method is determined based on the data type, the data to be processed is smoothed, and the noise intensity of the data before and after smoothing is calculated to verify the effect.

[0020] Temperature compensation is performed based on the different test media, and humidity and layer compensation are performed in combination with type data to correct environmental factor deviations and obtain pressure processing data.

[0021] This invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning. The steps for extracting feature evaluation indicators include: The characteristic index dimensions are determined based on the membrane pore structure characteristics, surface treatment status, and application scenarios' requirements for waterproof performance, and in association with the failure modes of the waterproof membrane.

[0022] A multimodal feature fusion algorithm is used to extract feature indicators from the stress processing data based on the feature indicator dimension.

[0023] The characteristic indicators are adjusted according to the surface treatment status, and the interference of surface characteristics on the signal is removed to obtain the characteristic evaluation indicators.

[0024] This invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning. The steps for extracting characteristic indicators include: Modal features are constructed by extracting stable modes, trend modes, and abrupt modes from stress processing data.

[0025] Modal features are standardized, and weighted summation is used to aggregate the standardized features within each modality. The weights are determined according to the needs of the application scenario to obtain the aggregated features.

[0026] An attention mechanism is used to calculate the feature weights of each modality aggregated feature.

[0027] Feature indices are obtained by fusing the aggregated features and corresponding feature weights of each modality.

[0028] This invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning, wherein the steps for adjusting characteristic indicators include: The interference mechanism is derived by considering the interference of the surface treatment state of the breathable membrane under test on pressure data and characteristic indicators.

[0029] Based on the interference mechanism, the stability mode, trend mode, and abrupt mode of different types of breathable membranes are adjusted to remove surface characteristic interference.

[0030] This invention provides a method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning. The steps for establishing characteristic index judgment criteria include: Based on the failure risk, environmental pressure limit, and media contact characteristics of the breathable membrane application scenario, the scenario requirements are converted into priority characteristic indicators.

[0031] The baseline range is mapped based on the average pore size, distribution density, and morphology of the membrane pores, and the baseline range is modified in conjunction with the surface treatment state. The performance boundary is obtained by combining the rated properties of the material.

[0032] By combining the priority of feature indicators and performance boundaries, a multi-level judgment standard is established to obtain the feature indicator judgment standard.

[0033] This invention provides a method for detecting waterproofing of breathable membranes based on dynamic differential pressure scanning. The steps for analyzing the causes of leakage include: The core abnormal indicators and related abnormal indicators are determined based on the deviation between the feature evaluation indicators and the feature indicator judgment criteria, and the abnormal dimension to which different abnormal indicators belong is determined.

[0034] A mapping relationship is established between the type data and the anomaly dimension, and potential mapping causes are obtained by eliminating interference causes that do not match the membrane properties.

[0035] Environmental interference, installation interference, and equipment error were ruled out from the potential causes of leakage. Physical observation and auxiliary testing were used for verification. The causes of leakage were classified according to membrane defects, surface treatment failures, and external interference.

[0036] On the other hand, the present invention provides a breathable membrane waterproofing detection system based on dynamic differential pressure scanning, comprising: The breathable membrane testing module is used to collect data on the type of breathable membrane, determine the waterproof test method based on the usage scenario of the breathable membrane, and obtain pressure data by performing pressure tests on both sides of the breathable membrane according to the waterproof test method.

[0037] The feature extraction module is used to preprocess the pressure data to obtain pressure treatment data, and then extract feature evaluation indicators from the pressure data by combining the membrane pore structure features and surface treatment status and using feature fusion method.

[0038] The performance judgment module is used to establish characteristic index judgment standards based on type data and usage scenarios, and to determine whether the characteristic evaluation index meets the characteristic index judgment standards. If it does, the current breathable membrane is judged to be qualified for waterproof performance.

[0039] The feedback optimization module is used to determine if the current waterproof performance of the breathable membrane is unqualified, analyze the current characteristic evaluation indicators to obtain the cause of leakage, and feed it back to the production process to optimize the process.

[0040] This invention provides a method and system for detecting waterproof breathable membranes based on dynamic differential pressure scanning. It employs a multimodal feature fusion algorithm to extract stable, trend, and abrupt change modes from pressure processing data, and uses a weighted summation method and attention mechanism for feature fusion, improving the detection accuracy for minute leaks. Feature indicators are adjusted according to the surface treatment state to remove interference from surface characteristics, and environmental compensation (temperature compensation, humidity compensation, and layer compensation) is used to correct environmental biases, reducing interference caused by surface treatment state and environmental factors, and improving the reliability of detection results. Through an automated pressure detection device and data acquisition system, rapid and efficient pressure data acquisition and processing are achieved, improving detection efficiency and making it suitable for rapid detection needs in large-scale production. Furthermore, feature indicator judgment criteria are established based on breathable membrane type data and usage scenarios, and feature evaluation indicators are extracted from pressure data by combining membrane pore structure characteristics and surface treatment state. This provides accurate waterproof performance data in the early stages of research and development, supporting product optimization and improvement. Furthermore, during the detection process, anomaly analysis of characteristic indicators identifies core and related abnormal indicators, eliminates environmental interference, installation interference, and equipment errors, and categorizes the causes of leakage. This allows for accurate identification of large leaks and provides detailed analysis of the causes, facilitating timely handling and improvement. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is one of the flowcharts of the breathable membrane waterproofing detection method based on dynamic differential pressure scanning provided in the embodiments of the present invention.

[0043] Figure 2 This is the second schematic flowchart of the breathable membrane waterproofing detection method based on dynamic differential pressure scanning provided in this embodiment of the invention.

[0044] Figure 3 This is the third flowchart of the breathable membrane waterproofing detection method based on dynamic differential pressure scanning provided in this embodiment of the invention.

[0045] Figure 4This is a schematic diagram of the process of the breathable membrane waterproof testing system based on dynamic differential pressure scanning provided in an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] The following is combined Figures 1-4 This invention describes a method and system for detecting waterproofing of breathable membranes based on dynamic differential pressure scanning.

[0048] like Figure 1 As shown, the waterproof testing method for breathable membranes based on dynamic differential pressure scanning provided in this embodiment of the invention includes: Collect data on the type of breathable membrane, determine the waterproof test method based on the usage scenario of the breathable membrane, and obtain pressure data by performing pressure tests on both sides of the breathable membrane according to the waterproof test method.

[0049] The steps to determine the waterproofing test method include: Based on the environmental pressure, contact media, and performance failure risks of the breathable membrane during application, the requirements of the usage scenario are transformed into waterproof testing targets.

[0050] When the application scenario is outdoor clothing / tent membrane, the core requirements are broken down into environmental pressure and contact medium. The methods to convert these into waterproof testing targets can include: applying a test pressure of 15-25 kPa to verify that the membrane does not leak under this pressure; using deionized water as the test medium; adding "surface water film dispersion verification" (pretreatment step); and ensuring a sufficiently long testing cycle (30-40 minutes) to focus on capturing the "pressure difference change trend of slow leakage".

[0051] A waterproof testing method is formed by combining waterproof testing targets with type data and mapping parameters such as pressure, testing cycle, test medium, and chamber environment control.

[0052] The pressure mapping for testing is based on the following: the upper limit of the environmental pressure is a preset safety factor (to avoid failure caused by pressure fluctuations in actual use), while not exceeding the membrane's "rated tolerance pressure" (to prevent membrane damage).

[0053] The mapping of the detection cycle is based on: the time required for the exposure of leakage risk in the scenario (e.g., slow leakage requires a long detection period), combined with the membrane pore structure (small-pore membranes leak slowly and require a longer cycle).

[0054] The mapping of the test medium is based on: the type of medium that the membrane actually contacts in the scenario (liquid / gas, cleanliness, corrosivity), combined with the membrane surface treatment status (media adaptability of hydrophobic / hydrophilic coatings).

[0055] The mapping of chamber environment control is based on the following factors: temperature, humidity, vibration and other interference factors of the scene environment, combined with the environmental sensitivity of membrane material / surface treatment (such as the plasma treatment layer being susceptible to temperature and humidity fluctuations).

[0056] Taking "breathable membrane for medical protective clothing" as an example, the integrated waterproof testing method is as follows: Test objective: To verify that there is no micro-leakage (equivalent pore size ≤ 0.3 μm) under pressure of 3-6 kPa and that it can withstand a humid and hot environment of 35℃.

[0057] Key parameters: Pressure applied: 3-6 kPa (applied in 3 stages: 3 kPa → 4.5 kPa → 6 kPa, each stage lasting 2 minutes).

[0058] Testing cycle: 25 minutes (5 minutes of pressure rise and stabilization phase + 20 minutes of continuous testing phase).

[0059] Test medium: clean air (dust content ≤0.1mg / m³, temperature 35±2℃, humidity 80±5%RH).

[0060] Chamber control: Equipped with a constant temperature and humidity module, vibration control ≤0.1g (to avoid interference with the detection of minute pressure differences).

[0061] Sample mounting: soft silicone clamp (Shore hardness 35), fluororubber sealing ring (to avoid adhesion and contamination of the membrane surface).

[0062] Data acquisition: Sampling frequency 10Hz, recording "timestamp-pressure difference", storage format is CSV.

[0063] The steps for obtaining pressure data include: Based on waterproof testing methods, a pressure testing device was constructed, comprising sealing tests, pressure control, differential pressure sensing, data acquisition, and environmental control.

[0064] Sealing tests may include: selecting chamber materials compatible with the test medium, ensuring the effective volume of the chamber matches the effective detection area of ​​the membrane, and assembling the sealing structure according to the test method requirements.

[0065] Pressure control may include: connecting a pressure source according to the type of test medium: for liquid media, connect a high-precision constant-pressure water pump; for gaseous media, connect a gas cylinder with a pressure regulating valve and a precision pressure controller. Setting pressure control parameters according to the test method: for example, if outdoor clothing membrane testing requires "step-by-step pressure application of 18-25 kPa", then set a step program of "increasing by 3 kPa every 2 minutes" in the pressure controller software to ensure that the pressure rise rate matches the membrane's pressure tolerance characteristics (avoiding instantaneous high pressure rupture of the membrane pores).

[0066] Differential pressure sensing and data acquisition may include: selecting a differential pressure sensor with appropriate resolution, range, and testing method. For example, if medical membrane testing requires capturing a "minor pressure difference of ±0.5 Pa", a micro differential pressure sensor with a resolution of 0.01 Pa and a range of ±100 Pa is selected. If outdoor membrane testing requires withstanding a "high pressure difference of 25 kPa", a differential pressure sensor with a range of 0-50 kPa and an accuracy of ±0.2% FS is selected.

[0067] Connect the two measurement ports of the sensor to the "high-pressure side" and "low-pressure side" of the sealed chamber respectively via inert gas tubing (the low-pressure side is usually open to the atmosphere or connected to another sealed chamber, depending on the test method), ensuring the tubing is leak-free. Set the sampling frequency: for electronic device membrane testing requiring "high-frequency capture of sudden changes," set it to 10Hz. For routine outdoor membrane testing, set it to 1-5Hz, and simultaneously set the data storage format.

[0068] Environmental control may include: if the test method requires "constant temperature and humidity" (e.g., medical membrane testing requires 35±2℃ and 80±5%RH), then the constant temperature and humidity module of the chamber is activated. After the temperature and humidity in the chamber reach the set value and remain stable for 30 minutes (fluctuation ≤ ±0.5℃ and ±2%RH), the subsequent steps can be performed.

[0069] The surface tension of the breathable membrane sample to be tested was pretreated to remove excess surface tension, and then positioned and fixed. The verification pressure was set according to the waterproof test method, and the sealing performance of the pressure testing device was verified.

[0070] The positioning and fixing steps include: measuring the actual thickness of the membrane to be tested; if the test method requires "compensation for membrane thickness difference", then inserting a polyimide gasket of the corresponding thickness (thickness error ≤ ±0.01mm) between the chamber flange and the membrane to ensure that the effective testing area of ​​the membrane is flat and wrinkle-free.

[0071] Cover the chamber with the membrane over the "effective detection window" (e.g., a circular window with a diameter of 50 mm), ensuring that the center of the membrane is aligned with the center of the window and that the edge of the membrane extends ≥5 mm beyond the edge of the window.

[0072] Use a ring-shaped pressure cap to evenly press the edge of the film together, and tighten the pressure cap bolts with a torque wrench according to the torque value set in the test method to ensure a uniform seal at the edge.

[0073] The pressure testing device, verified according to the applied pressure, was used to test the breathable membrane sample to be tested, and pressure data on both sides were collected at different stages.

[0074] Pressure data is preprocessed to obtain pressure treatment data. Feature evaluation indicators are extracted from the pressure data by combining the membrane pore structure characteristics and surface treatment status and using feature fusion method.

[0075] The steps to obtain stress processing data include: Based on pressure control, the pressure data is divided into nodes, and the pressure data within the stable range is extracted as the data to be processed.

[0076] Select an outlier identification method based on the data type, mark outliers from the data to be processed, and replace outliers using the adjacent data moving average method.

[0077] Based on the data type: If the breathable membrane is "large pore membrane=": use the box plot method to calculate the first quartile (Q1), the third quartile (Q3), and the interquartile range (IQR=Q3-Q1) of the data to be preprocessed, and mark the values ​​that exceed "Q1-1.5IQR" or "Q3+1.5IQR" as outliers.

[0078] If the breathable membrane is a "hydrophilic modified membrane": the 3σ criterion + multi-window verification method is adopted. First, the mean (μ) and standard deviation (σ) of the data are calculated, and the values ​​that exceed "μ±3σ" are marked. Then, it is verified whether the two sampling points before and after the value also exceed the threshold. Only when all three consecutive points exceed the limit is it judged as an outlier.

[0079] If the breathable membrane is a "plasma-treated membrane": the sudden change amplitude threshold method is adopted, and the "sudden change amplitude threshold" is set according to the membrane pore structure (e.g., ±6Pa when the average pore diameter is ≤0.1μm). Values ​​that exceed the threshold in a single pressure difference are marked as abnormal values.

[0080] The smoothing method is determined based on the data type, the data to be processed is smoothed, and the noise intensity of the data before and after smoothing is calculated to verify the effect.

[0081] If the breathable membrane has "irregular pores": wavelet transform denoising method is used, and the specific operation steps include: By selecting the db6 wavelet basis function, the pressure difference data is decomposed into 3-5 layers of wavelet components.

[0082] The threshold for each layer is calculated using the "default threshold method" and a "high-frequency noise threshold" is set to remove high-frequency noise components.

[0083] ③ Reconstruct the remaining wavelet components to obtain the denoised pressure difference data, ensuring that the nonlinear leakage trend is not disrupted.

[0084] If the breathable membrane is a "conventional uniform membrane pore": use the moving average filtering method, set the filtering window N=5-8 (the window size is adjusted according to the sampling frequency, set N=8 for 10Hz sampling, set N=5 for 1Hz sampling), take the average value of N consecutive data as the smoothing value of the current point, and balance noise elimination and trend following.

[0085] If the noise intensity decreases by ≥30% and the trend deviation rate is ≤5%, the smoothing effect is satisfactory. Otherwise, adjust the smoothing parameters (e.g., increase the window N, change the wavelet basis function) and reprocess.

[0086] Temperature compensation is performed based on the different test media, and humidity and layer compensation are performed in combination with type data to correct environmental factor deviations and obtain pressure processing data.

[0087] The temperature compensation steps may include: If the test medium is a "gas": calculate the temperature compensation using the "ideal gas law", the formula is expressed as:

[0088] In the formula, It's temperature compensation. This is the real-time pressure value. It is the preset standard reference temperature. It measures the real-time ambient temperature.

[0089] If the test medium is a "liquid": Consult the "Water Viscosity-Temperature Reference Table" to calculate the "Viscosity Correction Factor" (e.g., 1.00 at 25℃, 0.92 at 30℃). Calculate the temperature compensation based on the viscosity correction factor; the formula is as follows:

[0090] In the formula, It's temperature compensation. It is the viscosity correction factor.

[0091] Humidity compensation: If the breathable membrane is a "low pore density membrane (membrane pore distribution density < 5 × 10⁻⁶)" 8 If the humidity has a significant impact (e.g., PTFE microporous membranes), and the humidity change during the test exceeds ±3%RH, then look up the "membrane pore resistance-humidity curve" (drawn in advance through experiments), calculate the "humidity correction coefficient" (e.g., 1.00 for 50%RH and 1.03 for 60%RH), and multiply the real-time pressure value by the humidity correction coefficient to obtain humidity compensation.

[0092] If the breathable membrane is a "hydrophobic modified membrane (sensitive to temperature, coating performance fluctuates with temperature)", in addition to the conventional temperature compensation, an additional "hydrophobic coating temperature correction coefficient" (e.g., 1.00 for 23℃ and 1.005 for 28℃) is introduced. The humidity compensation is obtained by multiplying the real-time pressure value by the hydrophobic coating temperature correction coefficient.

[0093] like Figure 2 As shown, the steps for extracting feature evaluation metrics include: The characteristic index dimensions are determined based on the membrane pore structure characteristics, surface treatment status, and application scenarios' requirements for waterproof performance, and in association with the failure modes of the waterproof membrane.

[0094] A multimodal feature fusion algorithm is used to extract feature indicators from the stress processing data based on the feature indicator dimension.

[0095] like Figure 3 As shown, the steps for extracting feature indicators include: The pressure difference fluctuation range, maximum deviation of the continuous window, and stability decay rate in the pressure processing data constitute the stability mode. The pressure difference change rate, piecewise curvature change, and trend inflection time constitute the trend mode. The mutation frequency, maximum mutation amplitude, and high-risk mutation energy constitute the mutation mode.

[0096] Modal features consist of stable modes, trend modes, and abrupt modes.

[0097] Modal features are standardized, and weighted summation is used to aggregate the standardized features within each modality. The weights are determined according to the needs of the application scenario to obtain the aggregated features.

[0098] The feature weights of each modality aggregated feature are calculated using an attention mechanism, expressed by the following formula:

[0099]

[0100]

[0101] In the formula, It is a feature of the aggregation of stable modes. It is a feature of the aggregation of trend modes. It is a feature of the aggregation of abrupt modalities. , , It is the scene relevance coefficient. It is the first The original feature vectors of each modality, It is the first The weighting coefficients of each modality These are the feature weights of the stable modes. These are the feature weights of the trend mode. These are the feature weights of the abrupt mode.

[0102] The feature index is obtained by fusing the aggregated features and corresponding feature weights of each modality, and the formula is expressed as follows:

[0103] In the formula, It is a characteristic indicator.

[0104] The characteristic indicators are adjusted according to the surface treatment status, and the interference of surface characteristics on the signal is removed to obtain the characteristic evaluation indicators.

[0105] The steps for adjusting feature indicators include: The interference mechanism is derived by considering the interference of the surface treatment state of the breathable membrane under test on pressure data and characteristic indicators.

[0106] If the surface treatment type is hydrophobic modification (such as PTFE coating), the interference mechanism is identified as "temperature fluctuations cause changes in surface tension, leading to false fluctuations in pressure difference, and local wear of the coating exacerbates the instability of pressure difference in the later stage". The interference is manifested as an abnormal increase in the range of pressure difference fluctuation in the stability index and the appearance of a false leakage trend in the trend index.

[0107] If the surface treatment type is hydrophilic modification (such as hydrophilic resin coating), the interference mechanism is identified as "water vapor condensation in a high humidity environment blocks the membrane pores, causing a temporary increase in pressure difference, and the pressure difference drops back after water vapor evaporates, forming a trend reversal". The interference manifests as a false trend reversal in the trend indicators and an abnormal increase in the standard difference of pressure difference in the stability indicators.

[0108] If the surface treatment type is an anti-oil coating (such as a fluorocarbon coating), the interference mechanism is identified as "oil adhesion aggravates airflow disturbance, causing high-frequency pressure difference fluctuations, and uneven coating thickness leads to uneven pressure difference distribution". The interference is manifested as a falsely high mutation frequency in the mutation index and an abnormally high stability decay rate in the stability index.

[0109] If the surface treatment type is plasma treatment, the interference mechanism is identified as "sudden pressure difference change caused by local peeling of the treatment layer and water absorption of the treatment layer affecting the pressure sensor signal acquisition". The interference is manifested as a falsely high frequency of high-risk mutations in the mutation index and a large range of pressure difference fluctuations in the stability index.

[0110] Based on the interference mechanism, the stability mode, trend mode, and abrupt mode of different types of breathable membranes are adjusted to remove surface characteristic interference.

[0111] For oil-resistant coating films: Adjustment of abrupt change index: The pressure difference data is decomposed into 5 levels using the db4 wavelet basis, and the high-frequency interference components with a frequency >10Hz are removed before the data is reconstructed. The adjustment is then recalculated based on the reconstructed data.

[0112] Stability index adjustment: Adjust the original stability decay rate according to the formula, which is expressed as:

[0113] In the formula, It is the average thickness of the coating. Within the detection area The thickness measurements at each point (n≥5) represent the original stability decay rate. It corrects the stability decay rate.

[0114] For plasma treatment membranes: Mutability index adjustment: Through mutation amplitude-duration correlation analysis, if the mutation amplitude is greater than twice the threshold and the duration is less than 0.5s, the high-risk modulator is adjusted to a high-risk modulator; otherwise, the high-risk modulator is retained as a high-risk modulator.

[0115] Stability index adjustment: Introduce 10 kPa standard pressure, record the sensor reading deviation, and adjust the original deviation according to the formula to correct the pressure difference fluctuation range (adjust the adjustment value during adjustment).

[0116] Establish characteristic indicator judgment criteria based on type data and usage scenarios, and determine whether the characteristic evaluation indicators meet the characteristic indicator judgment criteria. If so, the current waterproof performance of the breathable membrane is deemed qualified.

[0117] The steps for establishing characteristic indicator judgment criteria include: Based on the failure risk, environmental pressure limit, and media contact characteristics of the breathable membrane application scenario, the scenario requirements are converted into priority characteristic indicators.

[0118] The baseline range is mapped based on the average pore size, distribution density, and morphology of the membrane pores, and the baseline range is modified in conjunction with the surface treatment state. The performance boundary is obtained by combining the rated properties of the material.

[0119] By combining the priority of feature indicators and performance boundaries, a multi-level judgment standard is established to obtain the feature indicator judgment standard.

[0120] Based on the priority of feature indicators, feature evaluation indicators are divided into core indicators and auxiliary indicators, and the grading criteria meet the following requirements: Qualified level: All core indicators meet the "strict range" and auxiliary indicators meet the "general range".

[0121] Level pending re-inspection: The core indicators meet the "strict range", but one auxiliary indicator exceeds the "general range" (re-inspection is required after investigating interference).

[0122] Unqualified: Any core indicator exceeds the "strict range", or two or more auxiliary indicators exceed the "general range".

[0123] In addition, detailed rules are provided to address specific interferences caused by surface treatments or particular scenarios, thus preventing misjudgments: Hydrophilic modified membrane (medical application): If the trend indicator shows "first rise and then fall", but the humidity fluctuation is > ±3%, it is judged as "awaiting re-inspection" (re-inspection is required after drying) rather than directly failing.

[0124] Plasma treatment film (electronic device scenario): If the abrupt change index shows "amplitude > twice the threshold but duration < 0.5s" once, it is judged as "to be re-inspected" (to check for treatment layer detachment, not damage to the body), rather than unqualified.

[0125] Oil-resistant coating film (automotive scenario): If the stability index "attenuation rate" exceeds the qualified range, but the coating wear thickness is less than 3% of the total thickness, it is judged as "to be re-inspected" (re-inspected after cleaning the oil stains).

[0126] Otherwise, the current breathable membrane is deemed to have unqualified waterproof performance. The current characteristic evaluation indicators are analyzed to find the cause of leakage, and the feedback is sent to the production process to optimize the process.

[0127] The steps to analyze and determine the cause of the leakage include: The core abnormal indicators and related abnormal indicators are determined based on the deviation between the feature evaluation indicators and the feature indicator judgment criteria, and the abnormal dimension to which different abnormal indicators belong is determined.

[0128] If the core anomaly is a stability indicator (such as a pressure difference fluctuation range deviation rate of 45% or a stability decay rate deviation rate of 38%), it is classified as a "stability anomaly," initially pointing to "uneven membrane pore distribution, coating wear, or poor installation and sealing."

[0129] If the core anomaly is a trend indicator (such as a pressure difference change rate deviation rate of 52% or a trend reversal that is not affected by humidity): it is classified as a "trend anomaly", initially pointing to "micropores in the membrane body, local enlargement of membrane pores, and failure of hydrophilic coating".

[0130] If the core anomaly is a mutation indicator (such as a mutation frequency deviation rate of 60% or a high-risk mutation amplitude deviation rate of 48%), it is classified as a "mutation anomaly" and initially points to "sudden damage to the membrane body, detachment of the plasma treatment layer, or blockage / impact on the membrane pores by impurities in the test medium".

[0131] A mapping relationship is established between the type data and the anomaly dimension, and potential mapping causes are obtained by eliminating interference causes that do not match the membrane properties.

[0132] If the stability is abnormal: uneven membrane pore distribution and fluctuations concentrated in the membrane edge area indicate localized leakage due to pore imbalance. When the wear thickness of the anti-oil coating exceeds 3% of the total thickness and the subsequent fluctuation range is more than twice that of the initial range, it indicates pressure differential instability caused by coating wear. When the material's pressure resistance is lower than the test pressure but the low-pressure test is normal, it indicates overpressure deformation of the material leading to air leakage.

[0133] For trend anomalies: When the membrane pore morphology is irregular and the pressure difference curve decreases rapidly, it indicates localized pore enlargement. When the hydrophilic coating peeling area is greater than 5% and a trend reversal occurs due to non-humidity interference, it indicates sudden leakage caused by coating peeling. When the average membrane pore diameter is greater than 0.3 μm and the leakage rate is greater than 0.2 mL / h, it indicates continuous micro-leakage of a large-pore membrane.

[0134] For abrupt anomalies: When the plasma treatment layer bonding strength is <5 N / cm and the duration of a high-risk abrupt change is <0.5 s, it is mapped to the treatment layer detaching and forming a momentary leakage channel. When the membrane pore fracture strength is <2 MPa and the pressure difference stabilizes at a low level after the abrupt change, it is mapped to the propagation of latent microcracks in the membrane body. When the test medium contains impurities with a particle size >0.5 μm and the abrupt change is concentrated in the initial stage of the test, it is mapped to impurities impacting the membrane pores.

[0135] Environmental interference, installation interference, and equipment error were ruled out from the potential causes of leakage. Physical observation and auxiliary testing were used for verification. The causes of leakage were classified according to membrane defects, surface treatment failures, and external interference.

[0136] like Figure 4 As shown, on the other hand, this embodiment also provides a waterproof testing system for breathable membranes based on dynamic differential pressure scanning. The waterproof testing system includes: The breathable membrane testing module is used to collect data on the type of breathable membrane, determine the waterproof test method based on the usage scenario of the breathable membrane, and obtain pressure data by performing pressure tests on both sides of the breathable membrane according to the waterproof test method.

[0137] The feature extraction module is used to preprocess the pressure data to obtain pressure treatment data, and then extract feature evaluation indicators from the pressure data by combining the membrane pore structure features and surface treatment status and using feature fusion method.

[0138] The performance judgment module is used to establish characteristic index judgment standards based on type data and usage scenarios, and to determine whether the characteristic evaluation index meets the characteristic index judgment standards. If it does, the current breathable membrane is judged to be qualified for waterproof performance.

[0139] The feedback optimization module is used to determine if the current waterproof performance of the breathable membrane is unqualified, analyze the current characteristic evaluation indicators to obtain the cause of leakage, and feed it back to the production process to optimize the process.

[0140] This embodiment provides a method and system for detecting waterproofing of breathable membranes based on dynamic differential pressure scanning. It employs a multi-modal feature fusion algorithm to construct a three-dimensional feature system: the stability mode extracted from pressure processing data reflects the membrane's long-term sealing capability, the trend mode captures the gradual process of minor leaks, and the abrupt change mode identifies sudden damage. Single-modal features are aggregated using a weighted summation method, and cross-modal weights are calculated using an attention mechanism, improving the detection accuracy of minor leaks. To address the specific interference of surface treatment conditions, false signals are removed using methods such as temperature correction coefficients, humidity correlation filtering, and wavelet high-frequency noise reduction. An environmental compensation algorithm is used to correct environmental factor biases, reducing the relative standard deviation of the detection results and eliminating the influence of factors on detection accuracy. This solution overcomes the shortcomings of existing technologies, such as insufficient detection accuracy for minor leaks, the influence of interference factors during the detection process, low detection efficiency, inability to provide accurate data in the early stages of research and development, and inadequate handling of large leaks. It achieves beneficial effects such as high-precision detection, high reliability, high-efficiency detection, research and development support, and detailed leakage cause analysis, significantly improving the performance and practicality of waterproofing detection for breathable membranes.

[0141] 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 part that contributes to the prior art, can be embodied in the form of a software product. 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.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the waterproofness of breathable membranes based on dynamic differential pressure scanning, characterized in that, include: Collect data on the type of breathable membrane, determine the waterproof test method according to the usage scenario of the breathable membrane, and obtain pressure data by performing pressure tests on both sides of the breathable membrane according to the waterproof test method. The pressure data is preprocessed to obtain pressure treatment data. Feature evaluation indicators are extracted from the pressure data by combining the membrane pore structure characteristics and surface treatment status and using feature fusion method. Based on the type data and the usage scenario, establish a feature index judgment standard, and determine whether the feature evaluation index meets the feature index judgment standard. If it does, determine that the current breathable membrane waterproof performance is qualified. Otherwise, the current breathable membrane is deemed to have unqualified waterproof performance. The current characteristic evaluation indicators are analyzed to find the cause of leakage, and the feedback is sent to the production process to optimize the process.

2. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 1, characterized in that, The steps for determining the waterproofing test method include: Based on the environmental pressure, contact medium, and performance failure risk of the breathable membrane during application, the requirements of the usage scenario are transformed into waterproof testing targets; The waterproof testing method is formed by mapping parameters from aspects such as pressure application, testing cycle, test medium, and chamber environment control, in conjunction with the aforementioned waterproof testing target and the aforementioned type of data.

3. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 2, characterized in that, The steps for obtaining the pressure data include: A pressure detection device comprising sealing test, pressure control, differential pressure sensing, data acquisition, and environmental control is constructed according to the waterproof testing method described above. The surface tension of the breathable membrane sample to be tested is pretreated to remove tension, and then positioned and fixed. The verification pressure is set according to the waterproof test method, and the sealing performance of the pressure detection device is verified. The pressure testing device, verified according to the applied pressure, is used to test the breathable membrane sample to be tested, and pressure data from both sides are collected at different stages.

4. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 3, characterized in that, The steps for obtaining the pressure processing data include: The pressure data is divided into nodes according to the pressure control, and the pressure data within the stable range is extracted as the data to be processed. Based on the type of data, an outlier identification method is selected, outliers are marked from the data to be processed, and the outliers are replaced using the adjacent data moving average method. Based on the data type, a smoothing method is determined, the data to be processed is smoothed, and the noise intensity of the data before and after smoothing is calculated to verify the effect. Temperature compensation is performed based on the different test media, and humidity and layer compensation are performed in combination with the aforementioned data to correct environmental factor deviations and obtain the pressure processing data.

5. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 1, characterized in that, The steps for extracting the feature evaluation indicators include: The characteristic index dimensions are determined based on the membrane pore structure characteristics, the surface treatment state, and the requirements of the application scenario for waterproof performance, and are correlated with the failure modes of the waterproof membrane. A multimodal feature fusion algorithm is used to extract feature indicators from the stress processing data based on the feature indicator dimensions; The feature index is obtained by adjusting the feature index according to the surface treatment state and removing the interference of surface characteristics on the signal.

6. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 5, characterized in that, The steps for extracting the feature indicators include: The stability mode, trend mode, and abrupt mode are extracted from the stress processing data to form modal features; The modal features are standardized, and the standardized features within each modality are aggregated using a weighted summation method. The weights are determined according to the requirements of the use case to obtain the aggregated features. An attention mechanism is used to calculate the feature weights of each modality aggregated feature; The feature index is obtained by fusing the aggregated features and corresponding feature weights of each modality.

7. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 6, characterized in that, The steps for adjusting the feature indicators include: The interference mechanism is derived based on the type of surface treatment state of the breathable membrane to be tested, which affects the pressure data and the characteristic indicators. Based on the interference mechanism, the stability mode, trend mode, and abrupt change mode of different types of breathable membranes are adjusted to remove surface characteristic interference.

8. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 7, characterized in that, The steps for establishing the characteristic index judgment criteria include: Based on the failure risk, environmental pressure limit, and media contact characteristics of the breathable membrane application scenario, the scenario requirements are converted into priority characteristic indicators. The baseline range is mapped based on the average pore size, distribution density, and morphology of the membrane pores, and the baseline range is corrected in conjunction with the surface treatment state. The performance boundary is obtained by combining the rated properties of the material. The feature index judgment criteria are obtained by establishing a multi-level judgment standard by combining the feature index priority and the performance boundary.

9. The method for detecting waterproofness of breathable membranes based on dynamic differential pressure scanning according to claim 1, characterized in that, The steps for analyzing and determining the cause of the leakage include: The core abnormal indicators and related abnormal indicators are determined based on the deviation between the feature evaluation indicators and the feature indicator judgment criteria, and the abnormal dimension to which different abnormal indicators belong is determined. A mapping relationship between the type of data and the abnormal dimension is established, and potential mapping causes are obtained by eliminating interference causes that do not match the membrane characteristics. Environmental interference, installation interference, and equipment error were excluded from the potential causes of leakage. Physical observation and auxiliary detection were used for verification. The causes of leakage were classified according to membrane defects, surface treatment failures, and external interference.

10. A waterproof testing system for breathable membranes based on dynamic differential pressure scanning, comprising the waterproof testing method for breathable membranes based on dynamic differential pressure scanning as described in any one of claims 1 to 9, characterized in that, The waterproof testing system includes: The breathable membrane testing module is used to collect data on the type of breathable membrane, determine the waterproof test method according to the usage scenario of the breathable membrane, and obtain pressure data by performing pressure tests on both sides of the breathable membrane according to the waterproof test method. The feature extraction module is used to preprocess the pressure data to obtain pressure treatment data, and extract feature evaluation indicators from the pressure data by combining the membrane pore structure features and surface treatment status and using feature fusion method. The performance determination module is used to establish a feature index determination standard based on the type data and the usage scenario, and to determine whether the feature evaluation index meets the feature index determination standard. If it does, the current waterproof performance of the breathable membrane is determined to be qualified. The feedback optimization module is used to determine if the current waterproof performance of the breathable membrane is unqualified, analyze the current characteristic evaluation indicators to obtain the cause of leakage, and feed it back to the production process to optimize the process.

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