Air suspension nylon tube water vapor barrier test method

Abstract

The invention relates to the technical field of barrier testing, in particular to an air suspension nylon tube water vapor barrier testing method, which comprises the following steps: determining a sampling method according to the production capacity and the production sequence of the same production batch of nylon tubes to select a plurality of detection nylon tubes and then divide the nylon tubes into a plurality of sampling detection groups, performing a standard experiment on the contrast detection group to determine standard experiment data and a quality standard characterization trend, and performing an adjustment experiment on the experiment detection group to determine adjustment experiment data and a quality adjustment characterization trend, and determining the quality characterization state of the nylon tube in the corresponding batch according to the judgment result of the quality standard characterization trend and the quality adjustment characterization trend, and determining the water vapor barrier property of the nylon tube according to the standard experiment data and the adjustment experiment data. And predicting the detection time of the nylon tubes of the production batch in use according to the quality characterization state and the water vapor barrier property. The method is beneficial for planning and maintaining in advance and guaranteeing reliable operation of the air suspension system.

Description

Technical Field

[0001] The invention relates to the technical field of barrier testing, and in particular to a water vapor barrier testing method for an air suspension nylon tube. Background Art

[0002] Air suspension systems play an increasingly important role in improving vehicle comfort, handling stability, etc., and nylon tubes are key components of air suspensions, and their quality and performance are directly related to the operation effect of the entire system: on the one hand, automobile manufacturing is moving towards high precision and high quality, and the requirements for quality indicators such as the water vapor barrier performance of nylon tubes are becoming more and more stringent. The traditional simple and extensive sampling detection method can no longer meet the needs; on the other hand, in the complex and changeable actual use environment, nylon tubes may be affected by various factors such as temperature, pressure, and vibration, which may cause changes in their performance. There is an urgent need for a set of testing technologies that can simulate different working conditions, comprehensively evaluate performance, and guide subsequent maintenance.

[0003] Chinese patent publication number CN118190746A discloses a water vapor barrier performance test system and method based on the pressure difference method, which relates to the field of water vapor barrier performance test technology, including a collection module for collecting and processing the operating data of the test equipment; an analysis module for calculating and analyzing the processed operating data of the test equipment, judging the state of the test equipment during vacuum operation, and calculating the water vapor permeability of the test sample; a control module for controlling the test equipment and displaying all data to assist staff in managing the test equipment. The invention uses the pressure difference method to perform double-layer tests of dry gas and humid gas and calculate the difference to obtain the water vapor barrier performance of the sample, and maintains real-time monitoring of the state of the test equipment during the vacuum operation of the test equipment, thereby avoiding test result errors caused by improper vacuum operation and effectively improving the accuracy of the test data. It can be seen that the invention has the following problems: The difficulties in quality control caused by the diversity of production batches and working conditions and the problem of failure to evaluate the inspection time were not considered. Summary of the invention

[0004] To this end, the present invention provides a water vapor barrier test method for an air suspension nylon tube, which is used to overcome the problems in the prior art such as difficult quality control, lack of means for performance evaluation, and blind use and maintenance caused by complex production batches, diverse working conditions, and lack of maintenance basis, so as to ensure that the quality of the nylon tube is reliable, the performance meets the standards, and the maintenance time is reasonably planned.

[0005] To achieve the above object, the present invention provides a water vapor barrier test method for an air suspension nylon tube, comprising: Determine a sampling method based on the production volume and production sequence of the same production batch of nylon tubes, and select a number of nylon tubes for testing based on the sampling method; Dividing the test nylon tube into a plurality of sampling test groups, wherein the sampling test groups at least include a control test group and an experimental test group; Performing a standard experiment on each test nylon tube in the control test group to determine its standard experimental data, and determining a quality standard characterization trend according to the standard experimental data of each test nylon tube, wherein the quality standard characterization trend includes a quality consistency trend and a quality variation trend; Performing an adjustment experiment on each test nylon tube of the experimental test group to determine its adjustment experiment data, and determining a quality adjustment characterization trend according to the adjustment experiment data of each test nylon tube, wherein the quality adjustment characterization trend includes a quality consistency trend and a quality variation trend; Determining the quality characterization state of the corresponding batch of nylon tubes according to the determination results of the quality standard characterization trend and the quality adjustment characterization trend, wherein the quality characterization state includes a stable state, an explicit fluctuation state, and an implicit fluctuation state; Determining the water vapor barrier performance of the nylon tube according to the quality characterization state, the standard experimental data, and the adjusted experimental data; The detection time of the nylon tube of this production batch during use is predicted based on the quality characterization status and water vapor barrier performance.

[0006] Further, the method for determining the sampling method according to the production volume and production sequence of the same production batch of nylon tubes includes: Determine the sampling quantity of the nylon tube to be tested according to the production volume and the preset sampling ratio; Determine the number of nodes of the sampling time node according to the sampling number and the number of sampling detection groups; Determine a number of sampling time nodes according to the number of nodes and the production sequence; At each sampling time point, a number of test nylon tubes are randomly selected for sampling and testing groups.

[0007] Further, the method of subjecting each test nylon tube of the control test group to a standard test includes: The test nylon tubes of the control test group are divided into a first control group and a second control group according to a preset grouping ratio; In the first control group, a humidity sensor is installed inside each test nylon tube and filled with a standard weight of resin, and a standard initial humidity inside each nylon tube is determined; In the second control group, each test nylon tube is internally installed with a humidity sensor and filled with silica gel of a standard weight, and the standard initial humidity and the standard initial silica gel chromaticity value inside each nylon tube are determined; The test nylon tube is placed in a standard experimental environment, wherein the standard experimental environment is an ambient temperature of 40° C. and an ambient relative humidity of 90%; End the experiment of the second control group at a first preset time and determine the standard change silica gel chromaticity value of each test nylon tube in the second control group, and determine the first standard humidity of each test nylon tube in the control test group; End the experiment of the first control group at a second preset time and determine the second standard humidity and the standard ending resin weight of each test nylon tube in the first control group; Wherein, the preset grouping ratio is greater than or equal to 1:1; The standard experimental data include standard initial humidity, first standard humidity, second standard humidity, standard initial silica gel chromaticity value, standard change silica gel chromaticity value, and standard final resin weight.

[0008] Further, the method for determining the quality standard characterization trend according to the standard test data of each tested nylon tube includes: Determine the first standard humidity difference of each test nylon tube according to the standard initial humidity and the first standard humidity to determine the first standard humidity standard deviation; Determine the standard deviation of the standard chromaticity value according to the standard variation silica gel chromaticity value of each test nylon tube; Determine the standard water absorption weight according to the standard weight of each tested nylon tube and the standard end resin weight to determine the standard deviation of the standard water absorption weight of each tested nylon tube; The quality standard characterization trend is determined according to the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation, wherein: If the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation meet the standard consistency condition, then the quality standard characterization trend is determined to be a quality consistency trend; If the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation do not meet the standard consistency condition, then the quality standard characterization trend is determined to be a quality uneven trend; Among them, the standard consistency condition is that the difference rate of any two standard deviation parameters among the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation is less than a preset value.

[0009] Furthermore, the method of adjusting the nylon tubes of the experimental detection group includes: Divide the test nylon tubes of the experimental test group into a first experimental group and a second experimental group according to a preset grouping ratio; In the first experimental group, a humidity sensor is installed inside each test nylon tube and filled with a standard weight of resin, and the adjusted initial humidity inside each nylon tube is determined; In the second experimental group, each test nylon tube was equipped with a humidity sensor and filled with a standard weight of silica gel, and the adjusted initial humidity and the adjusted initial silica gel chromaticity value inside each nylon tube were determined; Placing the detection nylon tube in an adjusted experimental environment, wherein the adjusted experimental environment includes a standard experimental environment and periodic pressure changes; Finishing the experiment of the second experimental group at the first preset time and determining the adjusted silica gel chromaticity value of each test nylon tube in the second experimental group, and determining the first adjusted humidity of each test nylon tube in the second experimental group; Finish the experiment of the first experimental group at a second preset time and determine the second adjusted humidity and the adjusted end resin weight of each test nylon tube in the first experimental group; The adjustment of the experimental data includes adjusting the initial humidity, the first adjustment humidity, the second adjustment humidity, adjusting the initial silica gel chromaticity value, adjusting the changed silica gel chromaticity value, and adjusting the final resin weight.

[0010] Further, the method for determining the quality adjustment characterization trend according to the adjustment experimental data of each tested nylon tube includes: Determine the first adjusted humidity difference of each detection nylon tube according to the adjusted initial humidity and the first adjusted humidity to determine the first adjusted humidity standard deviation; Determine the standard deviation of the adjusted chromaticity value according to the adjusted changed silica gel chromaticity value of each test nylon tube; Determine the adjusted water absorption weight according to the standard weight of each tested nylon tube and the adjusted end resin weight to determine the standard deviation of the adjusted water absorption weight of each tested nylon tube; The quality adjustment characterization trend is determined according to the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation, wherein: If the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation meet the adjustment consistency condition, then determining that the quality adjustment characterization trend is a quality consistency trend; If the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation do not meet the adjustment consistency condition, then determining that the quality adjustment characterization trend is a quality uneven trend; The adjustment consistency condition is that the difference rate of any two standard deviation parameters among the first adjustment humidity standard deviation, the adjustment chromaticity value standard deviation and the adjustment water absorption weight standard deviation is less than a preset value.

[0011] Further, the quality characterization status of the corresponding batch of nylon tubes is determined according to the determination results of the quality standard characterization trend and the quality adjustment characterization trend, including: If the quality characterization trend and the quality characterization trend are both quality consistent trends, it is determined that the quality characterization state of the corresponding batch of nylon tubes is a stable state; If the quality characterization trend and the quality characterization trend are both quality uneven trends, it is determined that the quality characterization state of the corresponding batch of nylon tubes is an explicit fluctuation state; If the quality characterization trend is different from the quality characterization trend, it is determined that the quality characterization state of the corresponding batch of nylon tubes is a hidden fluctuation state.

[0012] Further, the method for determining the water vapor barrier performance of the nylon tube according to the standard experimental data and the adjusted experimental data includes: Determine the standard water absorption rate of each tested nylon tube according to the ratio of each standard water absorption weight to the standard weight; Determine the adjusted water absorption rate of each tested nylon tube according to the ratio of each adjusted water absorption weight to the standard weight; Determine the average value of the standard water absorption and the average value of the adjusted water absorption respectively according to each of the standard water absorptions and each of the adjusted water absorptions; The water vapor barrier performance of the nylon tube is determined according to the average standard water absorption rate and the average adjusted water absorption rate.

[0013] Furthermore, the water vapor barrier performance is positively correlated with the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate, wherein: If the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate is less than the reference value, it is determined that the water vapor barrier performance does not meet the standard; If the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate is greater than or equal to the reference value, it is determined that the water vapor barrier performance meets the standard.

[0014] Further, the detection time of the nylon tube of the production batch during use is predicted based on the quality characterization status and water vapor barrier performance, including If the quality characterization state is a stable state and the water vapor barrier performance meets the standard, the inspection time of the nylon tube of the production batch during use is determined to be the standard inspection time; If the quality characterization state is a hidden fluctuation state and the water vapor barrier performance meets the standard, it is determined that the detection time of the nylon tube of the production batch during use is less than the standard detection time; If the quality characterization state is an explicit fluctuation state, or the quality characterization state is an implicit fluctuation state and the water vapor barrier performance does not meet the standard, it is determined that the nylon tube of this production batch will not be used.

[0015] Compared with the prior art, the beneficial effect of the present invention lies in that the water vapor barrier test method for air suspension nylon tubes provided by the present invention determines the sampling method according to the production volume and production sequence of the same production batch of nylon tubes through a reasonable sampling process, selects representative test nylon tubes, and ensures that the test results can reflect the quality of the entire batch of products; secondly, setting up a control test group and an experimental test group can not only accurately determine the standard experimental data and the quality characterization trend, but also compare and obtain the adjusted experimental data and the corresponding trend, providing a multi-dimensional basis for comprehensive judgment of product quality; furthermore, the quality characterization state of the corresponding batch of nylon tubes can be accurately determined according to the experimental results, covering stable, explicit fluctuation and implicit fluctuation states, so that the producer can see the product quality fluctuation at a glance; finally, the water vapor barrier performance is determined in combination with the standard and adjusted experimental data, and the detection time of the nylon tube when in use is predicted based on the quality characterization state and the performance, which is helpful to plan maintenance in advance and ensure the reliable operation of the air suspension system; Furthermore, the present invention adopts a rigorous, scientific and highly targeted sampling strategy, fully considering the scale differences of production batches, the setting of the test group and the consistency of the production process, to ensure that the samples extracted can not only accurately reflect the overall quality of the entire batch of nylon tubes, but also be closely connected with the subsequent experimental links, laying a solid foundation for the accuracy and reliability of the entire test; Furthermore, the present invention constructs a set of clear and accurate quality status judgment criteria by conducting rigorous and detailed comparative analysis on the quality standard characterization trend and the quality adjustment characterization trend, which can present the quality fluctuation of nylon tube batches in three intuitive states: stable, explicit fluctuation, and implicit fluctuation, providing a core basis for producers to quickly and accurately grasp product quality; Furthermore, based on a rigorous and scientific experimental data processing process, the present invention constructs a set of evaluation systems for accurately quantifying the water vapor barrier performance of nylon tubes, from calculating the standard water absorption rate and the adjusted water absorption rate respectively, to comprehensively considering the average values ​​of the two and comparing them with reference values, which provides key support for accurately judging the quality of nylon tubes and controlling product performance. Furthermore, the present invention integrates the two key indicators of quality characterization status and water vapor barrier performance to construct a nylon tube usage detection time prediction mechanism that fits the actual application scenario. It can not only accurately guide the reasonable use and maintenance arrangements of nylon tubes under different quality conditions, but also effectively ensure the overall reliability and safety of the air suspension system, and avoid the risk of failure caused by nylon tube problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a step diagram of a water vapor barrier test method for an air suspension nylon tube according to an embodiment of the present invention; Figure 2 A diagram of steps for determining a sampling method according to an embodiment of the present invention; Figure 3A flow chart for determining the water vapor barrier properties of a nylon tube according to an embodiment of the present invention; Figure 4 The flowchart of an embodiment of the present invention is used to predict the detection time of a nylon tube when in use. DETAILED DESCRIPTION

[0017] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0019] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0020] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] See also Figure 1 As shown, it is a step diagram of a water vapor barrier test method for an air suspension nylon tube according to an embodiment of the present invention. An embodiment of the present invention provides a water vapor barrier test method for an air suspension nylon tube, comprising: Step S1, determining a sampling method according to the production volume and production sequence of the same production batch of nylon tubes, and selecting a number of test nylon tubes according to the sampling method; Step S2, dividing the test nylon tubes into a plurality of sampling test groups, wherein the sampling test groups include at least a control test group and an experimental test group; it can be understood that the number of test nylon tubes in each sampling test group is equal; Step S3, performing a standard experiment on each test nylon tube of the control test group to determine its standard experimental data, and determining a quality standard characterization trend according to the standard experimental data of each test nylon tube, wherein the quality standard characterization trend includes a quality consistency trend and a quality variation trend; Step S4, performing an adjustment experiment on each test nylon tube of the experimental test group to determine its adjustment experiment data, and determining a quality adjustment characterization trend according to the adjustment experiment data of each test nylon tube, wherein the quality adjustment characterization trend includes a quality consistency trend and a quality variation trend; Step S5, determining the quality characterization state of the corresponding batch of nylon tubes according to the determination results of the quality standard characterization trend and the quality adjustment characterization trend, wherein the quality characterization state includes a stable state, an explicit fluctuation state, and an implicit fluctuation state; Step S6, determining the water vapor barrier performance of the nylon tube according to the standard experimental data and the adjusted experimental data; Step S7, predicting the inspection time of the nylon tube of the production batch when in use according to the quality characterization status and the water vapor barrier performance.

[0022] It can be understood that the present invention selects the nylon tubes for inspection taking into account the production volume and production sequence, avoiding the randomness and one-sidedness of sampling, so that the extracted samples reflect the true quality level of the entire batch of nylon tubes to the greatest extent, making the subsequent test results more convincing; the grouping mode of the control test group and the experimental test group can, on the one hand, establish a standard experimental data benchmark, and on the other hand, intuitively compare the differences brought about by the adjustment experiment, clearly show the quality performance of the nylon tube under different experimental conditions, and facilitate the rapid discovery of potential problems; by comparing the quality standard characterization trend and the quality adjustment characterization trend, the quality status of the nylon tube is refined into stability, explicit fluctuations and implicit fluctuations, so that producers can quickly understand the product quality stability and adjust the production process in time; the water vapor barrier performance is determined by comprehensive experimental data, and the inspection time during use is predicted based on the quality characterization status, which can not only control the current quality of the product, but also provide forward-looking guidance for the subsequent use and maintenance of the product, reduce the risk of use, extend the service life of the product, and improve the overall performance and safety of the air suspension.

[0023] See also Figure 2 As shown, it is a step diagram of determining the sampling method in an embodiment of the present invention. Specifically, in step S1, the method for determining the sampling method according to the production volume and production sequence of the same production batch of nylon tubes includes: Step S11, determining the number of samples to be tested for the nylon tube according to the production volume and the preset sampling ratio; it is understandable that the preset sampling ratio is usually 1 / 100 to 1 / 1000, and the larger the production volume of a single production batch, the smaller the preset sampling ratio; in implementation, the preset sampling ratio is 1 / 100 when the production volume is ≤10000, and the preset sampling ratio is 1 / 1000 when the production volume is >10000; the preset sampling ratio is flexibly adjusted according to the production volume. This dynamic setting method can ensure that there are enough samples for testing in small-scale production and accurately capture possible quality problems; it can also avoid waste of resources caused by excessive sampling in large-scale production, while ensuring that the samples are still representative, so that the sampling cost and the detection effect are optimally balanced; In practice, sampling quantity = preset sampling ratio × production volume; Step S12, determining the number of nodes of the sampling time nodes according to the sampling number and the number of sampling test groups; in implementation, the number of nodes = the sampling number ÷ the number of sampling test groups; it can be understood that the number of sampling test groups is ≥ 2 groups, that is, at least one control test group and one experimental test group are included; it can be understood that the number of sampling test groups is determined before the water vapor barrier performance test of the nylon tube is performed, and is usually two sampling test groups; Step S13, determining a number of sampling time nodes in sequence according to the number of nodes and the production sequence; It can be understood that the time intervals between any two adjacent sampling time nodes can be equal or unequal, and it is only necessary to select any time nodes in the same batch; In practice, the time intervals between any two adjacent sampling time nodes are usually equal to ensure that the nylon tubes from the beginning to the end of the production batch are sampled and tested, so as to ensure that the nylon tubes in the whole production stage are tested, which increases the representativeness of the sampling test; The number of sampling time nodes is determined by combining the number of samples with the number of sampling inspection groups, ensuring that nylon tubes produced in different periods have the opportunity to be included in the sample, effectively avoiding the omission of quality fluctuations caused by phased factors in the production process (such as replacement of raw material batches, restart of equipment after short-term fault repair, etc.), so that the sampling can fully cover the entire production process; in the implementation process, the time interval between any two adjacent sampling time nodes is usually equal to ensure that the nylon tubes from the beginning to the end of the production batch are sampled and inspected. In this way, whether it is the initial stage of production when the process has not yet been completely stable, or the products in the middle and late stages of maturity, they can be evenly sampled, covering the nylon tubes of the entire production stage to the greatest extent, greatly enhancing the representativeness of the sampling inspection, so that the final inspection results can truly reflect the quality status of the entire batch of nylon tubes in different production periods; Step S14, at each sampling time node, respectively select a sampling test group of test nylon tubes.

[0024] It can be understood that the number of test nylon tubes for sampling and testing groups is drawn according to each sampling time node, so that the sampling steps and the subsequent grouping experiment links are seamlessly connected; the drawn samples can directly correspond to the groups to carry out control tests and experimental tests, avoid sample confusion or mismatch, reduce the coordination costs of the intermediate links, and improve the execution efficiency of the entire testing process, creating favorable conditions for the subsequent rapid and accurate acquisition of experimental data.

[0025] It can be understood that step S3 includes step S31 and step S32, step S31 is to perform standard experiments on each test nylon tube of the control test group, and step S32 is to determine the quality standard characterization trend based on the standard experimental data of each test nylon tube.

[0026] Specifically, in step S31, the method of subjecting each test nylon tube of the control test group to a standard test includes: Step S311, dividing the test nylon tubes of the control test group into a first control group and a second control group according to a preset grouping ratio; it can be understood that since the first control group needs to conduct a long-term experiment, while the second control group does not need to conduct a long-term experiment, the number of test nylon tubes in the first control group is greater than or equal to the number of test nylon tubes in the second control group, and the preset ratio is usually 1:1 to 3:1; Step S312, installing a humidity sensor inside each test nylon tube in the first control group and filling it with a standard weight of resin, and determining a standard initial humidity inside each nylon tube; Step S313, installing a humidity sensor inside each test nylon tube in the second control group and filling it with silica gel of a standard weight, and determining a standard initial humidity and a standard initial silica gel chromaticity value inside each nylon tube; Step S314, placing the test nylon tube in a standard experimental environment, wherein the standard experimental environment is an ambient temperature of 40° C. and an ambient relative humidity of 90%; Step S315, ending the experiment of the second control group at the first preset time and determining the standard change silica gel chromaticity value of each test nylon tube in the second control group, and determining the first standard humidity of each test nylon tube in the control test group; Step S316, ending the experiment of the first control group at a second preset time and determining a second standard humidity and a standard ending resin weight of each test nylon tube in the first control group; Wherein, the preset grouping ratio is greater than or equal to 1:1; The standard experimental data include standard initial humidity, first standard humidity, second standard humidity, standard initial silica gel chromaticity value, standard change silica gel chromaticity value, and standard final resin weight.

[0027] It can be understood that when determining the chromaticity value of silica gel, images of the silica gel are taken around the circle, and the chromaticity value of each pixel point in the image around the circle is determined. The standard initial silica gel chromaticity value and the standard change silica gel chromaticity value are determined based on the average value of the chromaticity value of each pixel point.

[0028] In implementation, the first preset time is less than the second preset time; usually, the first preset time is between 48h and 120h, and the second preset time is greater than 1500h; preferably, the first preset time is set to 72h, and the second preset time is set to 2000 hours.

[0029] In implementation, the chromaticity value of a single pixel is the sum of the corresponding values ​​of the red channel, green channel, and blue channel of the pixel.

[0030] Specifically, in step S32, the method for determining the quality standard characterization trend according to the standard test data of each tested nylon tube includes: Step S321, determining the first standard humidity difference of each detected nylon tube according to the standard initial humidity and the first standard humidity to determine the first standard humidity standard deviation; it can be understood that the first standard humidity difference = the first standard humidity - the corresponding standard initial humidity; and then determining the first standard humidity standard deviation according to the standard deviation of the first standard humidity difference of each nylon tube; Step S322, determining the standard deviation of the standard chromaticity value according to the standard variation silica gel chromaticity value of each test nylon tube; it can be understood that the standard deviation of the standard chromaticity value is the standard deviation of the standard variation silica gel chromaticity value of each nylon tube; Step S323, determining the standard water absorption weight according to the standard weight of each tested nylon tube and the standard end resin weight to determine the standard deviation of the standard water absorption weight of each tested nylon tube; it can be understood that the standard water absorption weight = standard end resin weight - standard weight; the standard deviation of the standard water absorption weight is the standard deviation of the standard water absorption weight of each nylon tube; Step S324, determining the quality standard characterization trend according to the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation, wherein: If the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation meet the standard consistency condition, then the quality standard characterization trend is determined to be a quality consistency trend; If the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation do not meet the standard consistency condition, then the quality standard characterization trend is determined to be a quality uneven trend; Among them, the standard consistency condition is that the difference rate of any two standard deviation parameters among the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation is less than a preset value.

[0031] It can be understood that the difference rate of any two standard deviation parameters includes: (1) the difference rate a12 between the first standard humidity standard deviation a1 and the standard color value standard deviation a2, a12=|a1-a2|÷a1×100% or a12=|a1-a2|÷a2×100%, if a1 is less than a2, then a12=|a1-a2|÷a1×100%, if a1 is greater than a2, then a12=|a1-a2|÷a2×100%; (2) the difference rate a23 between the standard color value standard deviation a2 and the standard water absorption weight standard deviation a3, a23=|a2-a3|÷a2×100% or a 23=|a2-a3|÷a3×100%, if a2 is less than a3, then a23=|a2-a3|÷a2×100%, if a2 is greater than a3, then a23=|a2-a3|÷a3×100%; (3) the difference rate a13 between the standard deviation a1 of the first standard humidity and the standard deviation a3 of the standard water absorption weight, a13=|a1-a3|÷a1×100% or a13=|a1-a3|÷a3×100%, if a1 is less than a3, then a13=|a1-a3|÷a1×100%, if a1 is greater than a3, then a13=|a1-a3|÷a3×100%; In implementation, the smaller the preset value is, the smaller the difference between any two standard deviation parameters is, which means that the quality of the batch of nylon tubes is more consistent; usually, the preset value ∈ [1%, 5%].

[0032] It can be understood that step S4 includes step S41 and step S42, step S41 is to perform adjustment experiments on each test nylon tube of the experimental detection group, and step S42 is to determine the quality adjustment characterization trend based on the adjustment experiment data of each test nylon tube.

[0033] Specifically, in step S41, the method of performing an adjustment experiment on each test nylon tube of the test group includes: Step S411, dividing the test nylon tubes of the experimental test group into a first experimental group and a second experimental group according to a preset grouping ratio; Step S412, installing a humidity sensor inside each test nylon tube in the first experimental group and filling it with a standard weight of resin, and determining an adjusted initial humidity inside each nylon tube; Step S413, installing a humidity sensor inside each test nylon tube in the second experimental group and filling it with silica gel of a standard weight, and determining an adjusted initial humidity and an adjusted initial silica gel chromaticity value inside each nylon tube; Step S414, placing the test nylon tube in an adjustment experimental environment, wherein the adjustment experimental environment includes a standard experimental environment and periodic pressure changes; it can be understood that the purpose of adding periodic pressure changes is to consider the fatigue performance of the nylon tube and the sealing performance under fatigue, so the pressure change range should include its normal working pressure and the extreme pressure that may be encountered (20% to 30% above and below the working pressure); in implementation, the periodic pressure change is usually set to: no pressure-low pressure-medium pressure-high pressure-no pressure-low pressure-medium pressure-high pressure-no pressure... Such periodic changes usually have a cycle (a process of no pressure-low pressure-medium pressure-high pressure) of 4h to 6h, of which the duration of no pressure accounts for half (i.e., 2h to 3h), and the durations of low pressure, medium pressure, and high pressure are equal (the sum of the durations of the three pressure stages is equal to the duration of no pressure); During implementation, it is necessary to obtain the design limit pressure value of the nylon tube and the normal working pressure value of its usage scenario, and determine the corresponding pressures of low pressure, medium pressure and high pressure accordingly; the pressure of low pressure is 50% to 70% of the normal working pressure, the pressure of medium pressure is 80% to 120% of the normal working pressure, and the pressure of high pressure is 90% to 110% of the design limit pressure value.

[0034] Step S415, ending the experiment of the second experimental group at the first preset time and determining the adjusted silica gel chromaticity value of each test nylon tube in the second experimental group, and determining the first adjusted humidity of each test nylon tube in the second experimental group; Step S416, ending the experiment of the first experimental group at the second preset time and determining the second adjusted humidity and the adjusted end resin weight of each test nylon tube in the first experimental group; The adjustment of the experimental data includes adjusting the initial humidity, the first adjustment humidity, the second adjustment humidity, adjusting the initial silica gel chromaticity value, adjusting the changed silica gel chromaticity value, and adjusting the final resin weight.

[0035] It can be understood that the adjustment experiment adds the effect of pressure on the nylon tube on the basis of the standard experiment to accelerate the fatigue state of the nylon tube to determine the water vapor barrier performance of the nylon tube in the fatigue state.

[0036] Specifically, in step S42, the method for determining the quality adjustment characterization trend according to the adjustment experimental data of each tested nylon tube includes: Step S421, determining a first adjusted humidity difference of each detection nylon tube according to the adjusted initial humidity and the first adjusted humidity to determine a first adjusted humidity standard deviation; Step S422, determining the standard deviation of the adjusted chromaticity value according to the adjusted changed silica gel chromaticity value of each detected nylon tube; Step S423, determining the adjusted water absorption weight according to the standard weight of each tested nylon tube and the adjusted resin weight to determine the standard deviation of the adjusted water absorption weight of each tested nylon tube; Step S424, determining the quality adjustment characterization trend according to the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation, wherein: If the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation meet the adjustment consistency condition, then determining that the quality adjustment characterization trend is a quality consistency trend; If the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation do not meet the adjustment consistency condition, then determining that the quality adjustment characterization trend is a quality uneven trend; The adjustment consistency condition is that the difference rate of any two standard deviation parameters among the first adjustment humidity standard deviation, the adjustment chromaticity value standard deviation and the adjustment water absorption weight standard deviation is less than a preset value.

[0037] It is understandable that the method for determining the quality adjustment characterization trend is the same as the method for determining the quality standard characterization trend, and the selection of the preset value is also the same.

[0038] Specifically, in step S5, the quality characterization status of the corresponding batch of nylon tubes is determined according to the determination results of the quality standard characterization trend and the quality adjustment characterization trend, including: If the quality characterization trend and the quality characterization trend are both quality consistent trends, the quality characterization state of the corresponding batch of nylon tubes is determined to be a stable state; it can be understood that the stable state means that the product quality is stable under both conventional and adjusted test conditions, the production process is reliable, and there is no need to worry too much about quality variation, which is helpful to stabilize the production process and reasonably arrange subsequent production plans; If the quality characterization trend and the quality characterization trend are both quality variation trends, the quality characterization state of the corresponding batch of nylon tubes is determined to be an explicit fluctuation state; it can be understood that if both show a quality variation trend, it is determined to be an explicit fluctuation state; this indicates that there are obvious fluctuations in product quality, and production personnel should be prompted to immediately trace the source, check whether it is a raw material problem, equipment failure or process execution deviation, etc., and take corrective measures in a timely manner to prevent the large-scale output of defective products and ensure the overall quality level of the product; If the quality characterization trend is different from the quality characterization trend, the quality characterization status of the corresponding batch of nylon tubes is judged to be a latent fluctuation state; it is understandable that the standard and quality adjustment characterization trends are different and are judged to be a latent fluctuation state at the same time. This judgment can keenly detect potential quality changes that are not easy to find directly. Even if the product as a whole seems normal, subtle differences have been monitored, reminding producers to pay attention to subtle changes in factors in the production process, prevent possible large-scale quality problems in advance, and build a solid line of defense for continuous optimization of product quality.

[0039] It can be understood that step S5 effectively integrates the quality information reflected under different experimental conditions, so that producers no longer face scattered and ambiguous data, but can fully understand the product quality dynamics based on the clear quality characterization status. From macro production planning to micro process adjustment, accurate decisions can be made to achieve strong control over the quality of nylon tubes.

[0040] See also Figure 3 As shown, it is a flow chart of determining the water vapor barrier performance of a nylon tube according to an embodiment of the present invention. Specifically, in step S6, the method for determining the water vapor barrier performance of a nylon tube according to the standard experimental data and the adjusted experimental data includes: Step S61, determining the standard water absorption rate of each tested nylon tube according to the ratio of each standard water absorption weight to the standard weight; Step S62, determining the adjusted water absorption rate of each tested nylon tube according to the ratio of each adjusted water absorption weight to the standard weight; It can be understood that through steps S61 and S62, the standard water absorption rate is determined according to the ratio of each standard water absorption weight to the standard weight, and the adjusted water absorption rate is determined according to the ratio of each adjusted water absorption weight to the standard weight, so that the water absorption of the nylon tube is accurately quantified. This meticulous data processing method enables the degree of water vapor absorption of the nylon tube under different experimental conditions to be intuitively presented, laying a solid foundation for subsequent performance evaluation; Step S63, respectively determining the average standard water absorption rate and the average adjusted water absorption rate according to each of the standard water absorption rates and each of the adjusted water absorption rates; it can be understood that step S63 further calculates the average values ​​according to each of the standard water absorption rates and the adjusted water absorption rates, so as to avoid the one-sidedness of a single data, comprehensively reflect the water absorption characteristics of the entire group of tested nylon tubes, and enable the manufacturer to grasp the moisture absorption tendency of the product under normal and adjusted conditions from a macro level, and provide data basis for comparing different batches or optimizing the production process; Step S64, determining the water vapor barrier performance of the nylon tube according to the standard water absorption average value and the adjusted water absorption average value; it can be understood that in step S64, the water vapor barrier performance is clearly determined by comparing the ratio of the standard water absorption average value to the adjusted water absorption average value with the reference value; this clear judgment rule allows producers to quickly and accurately know whether the product performance meets the standards. When the ratio is less than the reference value, the problem can be detected and improved in time; if it is greater than or equal to the reference value, it is confirmed that the product performance is reliable, ensuring that the quality of the nylon tube put into use is excellent.

[0041] Specifically, in step S64, the water vapor barrier performance is positively correlated with the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate, wherein: If the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate is less than the reference value, it is determined that the water vapor barrier performance does not meet the standard; If the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate is greater than or equal to the reference value, it is determined that the water vapor barrier performance meets the standard.

[0042] It can be understood that the average value of the standard water absorption is ≤ the average value of the adjusted water absorption. The larger the ratio of the average value of the standard water absorption to the average value of the adjusted water absorption, the closer the two values ​​are, indicating that the water vapor barrier performance of the nylon tube in the fatigue state is better, that is, the water vapor barrier performance of the nylon tube of this batch is better; In implementation, the reference value ∈ [0.7, 0.85], and a larger reference value indicates a better water vapor barrier performance.

[0043] See also Figure 4 As shown, it is a flow chart of predicting the detection time of nylon tubes when in use according to an embodiment of the present invention. Specifically, in step S7, the detection time of the nylon tubes of the production batch when in use is predicted according to the quality characterization state and the water vapor barrier performance, including If the quality characterization state is a stable state and the water vapor barrier performance meets the standard, the inspection time of the nylon tube of the production batch during use is determined to be the standard inspection time; If the quality characterization state is a hidden fluctuation state and the water vapor barrier performance meets the standard, or the quality characterization state is a stable state and the water vapor barrier performance does not meet the standard, it means that the nylon tube of this production batch may not have the good performance of the nylon tube determined in the design stage, so it is determined that the detection time of the nylon tube of this production batch when in use is less than the standard detection time; it can be understood that the detection time is usually 0.7 times the standard detection time to 0.9 times the standard detection time; It is understandable that this range (0.7 times the standard inspection time to 0.9 times the standard inspection time) can detect potential problems before obvious product failures, compared with maintenance performed completely according to the standard inspection time. It does not overly compress the inspection time, thus avoiding the waste of manpower and material resources caused by too frequent inspections. At the same time, it does not completely follow the regular intervals, but appropriately increases the frequency of attention to nylon tubes with potential hazards. If the quality characterization state is an explicit fluctuation state, or the quality characterization state is an implicit fluctuation state and the water vapor barrier performance does not meet the standard, it is determined that the nylon tube of this production batch will not be used; in implementation, it can be used in stages in places where water vapor barrier performance requirements are not high; this screening mechanism prevents inferior nylon tubes from flowing into key application scenarios from the source, ensuring the safe operation of high-requirement parts such as automobile air suspension; at the same time, it reasonably arranges the destination of products that still have certain utilization value to avoid waste of resources and maximize benefits.

[0044] It is understandable that when nylon tubes are used in automobile air suspensions, a maintenance time (i.e. standard inspection time) is usually recommended, and this maintenance time is determined during the production design stage of the nylon tubes.

[0045] It is understandable that the complete judgment process in step S7 closely links the quality information of the nylon tube with the actual use and maintenance. Users no longer blindly follow the fixed maintenance mode, but dynamically and flexibly adjust the detection strategy according to the actual quality of the product. This not only improves the performance of the nylon tube itself, but also ensures the stable and reliable operation of the air suspension and even the entire automotive system, thereby enhancing the comprehensive competitiveness of the product.

[0046] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. The water vapor barrier test method for air suspension nylon tube is characterized by: include: Determine the sampling method according to the production volume and production sequence of the same production batch of nylon tubes, and select a number of nylon tubes for testing according to the sampling method; Dividing the test nylon tube into a plurality of sampling test groups, wherein the sampling test groups at least include a control test group and an experimental test group; Performing a standard experiment on each test nylon tube in the control test group to determine its standard experimental data, and determining a quality standard characterization trend according to the standard experimental data of each test nylon tube, wherein the quality standard characterization trend includes a quality consistency trend and a quality variation trend; Performing an adjustment experiment on each test nylon tube of the experimental test group to determine its adjustment experiment data, and determining a quality adjustment characterization trend according to the adjustment experiment data of each test nylon tube, wherein the quality adjustment characterization trend includes a quality consistency trend and a quality variation trend; Determining the quality characterization state of the corresponding batch of nylon tubes according to the determination results of the quality standard characterization trend and the quality adjustment characterization trend, wherein the quality characterization state includes a stable state, an explicit fluctuation state, and an implicit fluctuation state; Determining the water vapor barrier performance of the nylon tube according to the standard experimental data and the adjusted experimental data; The detection time of the nylon tube of this production batch during use is predicted based on the quality characterization status and water vapor barrier performance.

2. The air suspension nylon tube water vapor barrier test method according to claim 1, characterized in that: The methods for determining the sampling method based on the production volume and production sequence of the same production batch of nylon tubes include: Determine the sampling quantity of the nylon tube to be tested according to the production volume and the preset sampling ratio; Determine the number of nodes of the sampling time node according to the sampling number and the number of sampling detection groups; Determine a number of sampling time nodes according to the number of nodes and the production sequence; At each sampling time point, a number of test nylon tubes are randomly selected for sampling and testing groups.

3. The air suspension nylon tube water vapor barrier test method according to claim 2, characterized in that: The method of subjecting each test nylon tube of the control test group to a standard experiment includes: The test nylon tubes of the control test group are divided into a first control group and a second control group according to a preset grouping ratio; In the first control group, a humidity sensor is installed inside each test nylon tube and filled with a standard weight of resin, and a standard initial humidity inside each nylon tube is determined; In the second control group, each test nylon tube is internally installed with a humidity sensor and filled with silica gel of a standard weight, and the standard initial humidity and the standard initial silica gel chromaticity value inside each nylon tube are determined; The test nylon tube is placed in a standard experimental environment, wherein the standard experimental environment is an ambient temperature of 40° C. and an ambient relative humidity of 90%; End the experiment of the second control group at a first preset time and determine the standard change silica gel chromaticity value of each test nylon tube in the second control group, and determine the first standard humidity of each test nylon tube in the control test group; End the experiment of the first control group at a second preset time and determine the second standard humidity and the standard ending resin weight of each test nylon tube in the first control group; Wherein, the preset grouping ratio is greater than or equal to 1:1; The standard experimental data include standard initial humidity, first standard humidity, second standard humidity, standard initial silica gel chromaticity value, standard change silica gel chromaticity value, and standard final resin weight.

4. The air suspension nylon tube water vapor barrier test method according to claim 3, characterized in that: The method for determining the quality standard characterization trend based on the standard test data of each tested nylon tube includes: Determine the first standard humidity difference of each test nylon tube according to the standard initial humidity and the first standard humidity to determine the first standard humidity standard deviation; Determine the standard deviation of the standard chromaticity value according to the standard variation silica gel chromaticity value of each test nylon tube; Determine the standard water absorption weight according to the standard weight of each tested nylon tube and the standard end resin weight to determine the standard deviation of the standard water absorption weight of each tested nylon tube; The quality standard characterization trend is determined according to the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation, wherein: If the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation meet the standard consistency condition, then the quality standard characterization trend is determined to be a quality consistency trend; If the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation do not meet the standard consistency condition, then the quality standard characterization trend is determined to be a quality uneven trend; Among them, the standard consistency condition is that the difference rate of any two standard deviation parameters among the first standard humidity standard deviation, the standard color value standard deviation and the standard water absorption weight standard deviation is less than a preset value.

5. The air suspension nylon tube water vapor barrier test method according to claim 1, characterized in that: The method of adjusting the nylon tubes of the experimental detection group includes: Divide the test nylon tubes of the experimental test group into a first experimental group and a second experimental group according to a preset grouping ratio; In the first experimental group, a humidity sensor is installed inside each test nylon tube and filled with a standard weight of resin, and the adjusted initial humidity inside each nylon tube is determined; In the second experimental group, each test nylon tube was equipped with a humidity sensor and filled with a standard weight of silica gel, and the adjusted initial humidity and the adjusted initial silica gel chromaticity value inside each nylon tube were determined; Placing the detection nylon tube in an adjusted experimental environment, wherein the adjusted experimental environment includes a standard experimental environment and periodic pressure changes; Finishing the experiment of the second experimental group at the first preset time and determining the adjusted silica gel chromaticity value of each test nylon tube in the second experimental group, and determining the first adjusted humidity of each test nylon tube in the second experimental group; Finish the experiment of the first experimental group at a second preset time and determine the second adjusted humidity and the adjusted end resin weight of each test nylon tube in the first experimental group; The adjustment of the experimental data includes adjusting the initial humidity, the first adjustment humidity, the second adjustment humidity, adjusting the initial silica gel chromaticity value, adjusting the changed silica gel chromaticity value, and adjusting the final resin weight.

6. The air suspension nylon tube water vapor barrier test method according to claim 5, characterized in that: The method for determining the quality adjustment characterization trend based on the adjustment experimental data of each tested nylon tube includes: Determine the first adjusted humidity difference of each detection nylon tube according to the adjusted initial humidity and the first adjusted humidity to determine the first adjusted humidity standard deviation; Determine the standard deviation of the adjusted chromaticity value according to the adjusted changed silica gel chromaticity value of each test nylon tube; Determine the adjusted water absorption weight according to the standard weight of each tested nylon tube and the adjusted end resin weight to determine the standard deviation of the adjusted water absorption weight of each tested nylon tube; The quality adjustment characterization trend is determined according to the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation, wherein: If the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation meet the adjustment consistency condition, then determining that the quality adjustment characterization trend is a quality consistency trend; If the first adjusted humidity standard deviation, the adjusted chromaticity value standard deviation and the adjusted water absorption weight standard deviation do not meet the adjustment consistency condition, then determining that the quality adjustment characterization trend is a quality uneven trend; The adjustment consistency condition is that the difference rate of any two standard deviation parameters among the first adjustment humidity standard deviation, the adjustment chromaticity value standard deviation and the adjustment water absorption weight standard deviation is less than a preset value.

7. The air suspension nylon tube water vapor barrier test method according to claim 1, characterized in that: Determining the quality characterization status of the corresponding batch of nylon tubes according to the determination results of the quality standard characterization trend and the quality adjustment characterization trend includes: If the quality characterization trend and the quality characterization trend are both quality consistent trends, it is determined that the quality characterization state of the corresponding batch of nylon tubes is a stable state; If the quality characterization trend and the quality characterization trend are both quality uneven trends, it is determined that the quality characterization state of the corresponding batch of nylon tubes is an explicit fluctuation state; If the quality characterization trend is different from the quality characterization trend, it is determined that the quality characterization state of the corresponding batch of nylon tubes is a hidden fluctuation state.

8. The air suspension nylon tube water vapor barrier test method according to claim 1, characterized in that: The method for determining the water vapor barrier performance of the nylon tube according to the standard experimental data and the adjusted experimental data comprises: Determine the standard water absorption rate of each tested nylon tube according to the ratio of each standard water absorption weight to the standard weight; Determine the adjusted water absorption rate of each tested nylon tube according to the ratio of each adjusted water absorption weight to the standard weight; Determine the average value of the standard water absorption and the average value of the adjusted water absorption respectively according to each of the standard water absorptions and each of the adjusted water absorptions; The water vapor barrier performance of the nylon tube is determined according to the average standard water absorption rate and the average adjusted water absorption rate.

9. The air suspension nylon tube water vapor barrier test method according to claim 8, characterized in that: The water vapor barrier performance is positively correlated with the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate, wherein: If the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate is less than the reference value, it is determined that the water vapor barrier performance does not meet the standard; If the ratio of the average value of the standard water absorption rate to the average value of the corresponding adjusted water absorption rate is greater than or equal to the reference value, it is determined that the water vapor barrier performance meets the standard.

10. The air suspension nylon tube water vapor barrier test method according to claim 8, characterized in that: Predict the inspection time of the nylon tube of this production batch in use based on the quality characterization status and water vapor barrier performance, including If the quality characterization state is a stable state and the water vapor barrier performance meets the standard, the inspection time of the nylon tube of the production batch during use is determined to be the standard inspection time; If the quality characterization state is a hidden fluctuation state and the water vapor barrier performance meets the standard, it is determined that the detection time of the nylon tube of the production batch during use is less than the standard detection time; If the quality characterization state is an explicit fluctuation state, or the quality characterization state is an implicit fluctuation state and the water vapor barrier performance does not meet the standard, it is determined that the nylon tube of this production batch will not be used.

Images