A method for detecting the stability of PET film

Abstract

The invention discloses a method for detecting the stability of a PET film, and relates to the technical field of PET film detection. The invention solves the problem that the original test method can only identify bad products or normal products, but cannot fully analyze the relevant stability performance of the corresponding normal products, and the test process is not comprehensive, and a better detection effect cannot be achieved. The invention detects the tension by giving priority to confirming the characteristic points and characteristic areas, and identifies the weak areas based on the length changes thereof. Subsequently, the real weak areas are determined by analyzing the thickness values ​​of the weak areas and the associated areas. The confirmed weak areas are the most accurate areas, that is, the areas with the most balanced thickness values, and also the weakest and most accurate areas. Based on the determination of this area, the final stability parameters can be identified, the accuracy of the stability parameters is guaranteed, and the relevant stability performance of the product to be tested can be fully demonstrated.

Description

Technical Field

[0001] The invention relates to the technical field of PET film detection, in particular to a method for detecting the stability of a PET film. Background Art

[0002] PET film is a high-performance thermoplastic polyester film with excellent physical and mechanical properties and chemical stability; PET film, full name polyethylene terephthalate, is a polymer made by polycondensation of terephthalic acid and ethylene glycol. This material exhibits good physical and mechanical properties in a wide temperature range, with a heat resistance of up to 120°C, and has the advantages of good electrical insulation, fatigue resistance, friction resistance, and dimensional stability.

[0003] During the relevant testing process of PET film, the relevant test conditions of the PET film are generally displayed based on the testing process of its relevant equipment. During the tensile test, the overall stability of the corresponding PET film is evaluated by identifying whether the corresponding film is torn when it is pulled under the corresponding tensile force. However, this method can only identify poor products or normal products, but cannot fully analyze the relevant stability performance of the corresponding normal products. The testing process is not comprehensive and cannot achieve better testing results. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for detecting the stability of a PET film, which solves the problem that the original testing method can only identify bad products or normal products, but cannot fully analyze the relevant stability performance of the corresponding normal products, and the testing process is not comprehensive and cannot achieve better detection effects.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: A method for detecting the stability of a PET film comprises the following steps:

[0006] S1. Select a group of test products from the PET films to be tested, and use relevant high-definition equipment to perform a preliminary scan on the test products to determine the scanned image. Then, based on the scanned image, perform a preliminary inspection on the outer surface of the test products to identify whether there are defects on the outer surface. The specific method is as follows:

[0007] S11, determining the overall area of ​​the display surface corresponding to the scanned image, and dividing the display surface into N micro-areas of micro-area, where N is a preset value;

[0008] S12, marking a micro-area at the corner of the display surface as the initial area, starting from the initial area, comparing the initial area with other micro-areas, and confirming the comparison overlap degree BH i , where i represents different micro-regions:

[0009] If BH iAll meet: BH i ≥90%, it means the alignment is correct and the correct signal is generated;

[0010] If BH i None: BH i ≥90%, then reselect a set of initial regions and compare the overlap results to meet BH i ≥90% of the micro-areas are marked as normal areas, and the coincidence comparison results do not meet the BH i ≥90% of the micro-areas are marked as abnormal areas. If the selected initial area is still in the state that does not meet the BH i ≥90%, the initial region is selected again. If all micro-regions are selected as the initial region and BH still occurs i If the error rate is ≥90%, an error signal is directly generated for display;

[0011] If BH i There exists a satisfying BH i ≥90% of the relevant micro-areas, the corresponding relevant micro-areas will be marked as normal areas, which will meet the BH i ≥90% of the relevant micro-areas were marked as abnormal areas;

[0012] S13, the external operator directly performs subsequent test analysis based on the correct signal generated and executes the analysis process of step S2, and performs on-site identification based on the error signal or abnormal area generated, assesses whether there are defects on the surface of the product to be tested, and decides whether to perform subsequent test analysis and execute the analysis process of step S2;

[0013] S2. Place the object to be tested in the tensile instrument. After clamping both sides of the object to be tested, perform relevant monitoring on the object to be tested based on high-definition equipment, determine virtual feature points on the surface of the object to be tested, perform preliminary tensile testing on the object to be tested, identify whether the tensile test meets the standard, and then determine the weak area based on the changes in the feature areas between the feature points, including:

[0014] S21, adjusting the internal distance of the stretching device so that the object to be tested is in a taut state, wherein the taut state is determined by the operator, and controlling the high-definition device to obtain a surface image of the object to be tested at the current moment;

[0015] S22, confirming the edge lines between the clamping parts on both sides of the relevant stretching equipment and the tested product, confirming the clamping image between the two groups of edge lines from the surface image, connecting the center points of the two groups of edge lines, determining a group of center lines, and dividing them into M groups of micro-line segments based on the distance length L of the center lines, wherein the distance of each group of micro-line segments is equal, and M is a preset value, marking the segmentation points of adjacent micro-line segments and the selected center points as feature points, and the longitudinal area between the feature points as the feature area;

[0016] S23, adjust the tension of the stretching instrument to a standard value, where the standard value is a preset value, so that the clamps on both sides of the stretching instrument move away synchronously at a consistent moving rate. When the clamps on both sides move to X1m, stop stretching, where X1 is a preset value. Based on the real-time monitoring results of the high-definition device, determine the length change between the feature points, and calibrate the distance between different adjacent feature points as L k , where k represents different adjacent feature points and can also represent different feature areas;

[0017] S24, several groups L k Perform variance processing to determine the variance value Fc1, and compare the variance value Fc1 with the preset value Y1: when Fc1≥Y1, it means that the tensile test of the tested product does not meet the standard, and a tensile failure signal is generated for display; when Fc1<Y1, execute step S25;

[0018] S25, compare the variance value Fc1 with the preset value Y2. When Fc1>Y2, it means there is a weak area, and the weak area needs to be determined. Then, step S26 is executed, where Y2<Y1. When Fc≤Y2, a superior signal is generated.

[0019] S26, from several groups L k Eliminate a group of maximum values, and then confirm the variance to get the variance value Fc2, and stop when the variance value Fc2 ≤ Y2. k The relevant characteristic areas are marked as weak areas;

[0020] S3. Based on the confirmed weak area, select the associated area of ​​the weak area from other surrounding characteristic areas, and use relevant equipment to determine the thickness parameters of the associated area and the weak area, and identify the real weak area based on the display of the thickness parameters. The specific method is as follows:

[0021] S31, based on the determined weak area, identifying whether there is a weak area in the adjacent characteristic areas around the weak area, if not, marking the two groups of characteristic areas adjacent to the weak area as associated areas, if yes, treating the weak area and the adjacent weak areas as a whole weak area, and determining the associated areas in the same way;

[0022] S32, using relevant equipment to confirm the thickness data of the associated areas and the weak areas in the middle one by one, starting from one side line of one group of associated areas to the other side line of another group of associated areas, arranging the confirmed thickness data one by one to generate a thickness sequence {H1, H2, ..., Hm};

[0023] S33, starting from the first set of parameters H1 of the thickness sequence, confirm the difference between H1 and H2, where the difference is greater than 0:

[0024] If the difference is less than Y3, where Y3 is a preset value, H1 and H2 are classified as the same type of values, and then the difference between H2 and H3 is determined. If the difference is less than Y3, H1, H2 and H3 are all classified as the same type of values. j With H j+1 When the difference between the two is ≥Y3, the parameter sequence {H1, ..., H j} are divided into similar values, and then from H j+1 At the beginning, the differences between the adjacent parameters are confirmed one by one, and so on, several groups of parameter sequences are confirmed;

[0025] If the difference is ≥ Y3, start from H2 and mark H1 as an outlier, determine the difference between H2 and H3, and if the difference is < Y3, classify H1, H2 and H3 as the same type. j With H j+1 When the difference between the two is ≥Y3, the parameter sequence {H1, ..., H j} are divided into similar values, and then from H j+1 At the beginning, the differences between the adjacent parameters are confirmed one by one, and so on, several groups of parameter sequences are confirmed;

[0026] S34, performing mean processing on the thickness data within each parameter sequence to determine a pending mean value Jq, where q represents different parameter sequences, and when the pending mean value Jq < Y4, calibrating the scanning area corresponding to the corresponding parameter sequence as a true weak area;

[0027] S4. Based on the specific area ratio of the real weak area, identify and display the stability parameters of the product to be tested. The specific method is as follows:

[0028] Based on the total area value MM of several real weak areas, where several includes one, the area value LM of the corresponding clamped image after being stretched is confirmed;

[0029] Use MM÷LM=ZB to confirm the specific area ratio ZB;

[0030] The stability parameter WD is determined using WD=1-ZB and displayed.

[0031] Preferably, in step S33, when the to-be-determined mean value Jq≥Y4, no calibration is performed.

[0032] The present invention provides a method for detecting the stability of a PET film. Compared with the prior art, the present invention has the following advantages:

[0033] Beneficial effects:

[0034] The present invention can fully accommodate multiple films of different models or colors for testing by using the film body itself comparison method, thereby ensuring the comprehensiveness of the testing process. The comparison coincidence determined is the ratio of the same area of ​​the two to the area of ​​the two. Since the areas of different areas are the same, the ratio of the overlapping area is the corresponding coincidence, which is very convenient for confirmation.

[0035] When testing the tensile force, priority is given to confirming the characteristic points and characteristic areas, and based on their length changes, the weak areas are identified. Subsequently, the thickness values ​​of the weak areas and related areas are analyzed to determine the real weak areas. The confirmed weak areas are the most accurate areas, that is, the areas with the most balanced thickness values, and also the weakest and most accurate areas. Based on the determination of this area, the final stability parameters can be identified to ensure the accuracy of the stability parameters, which can fully demonstrate the relevant stability performance of the product to be tested. Moreover, by confirming the real weak areas, the confirmed values ​​are more accurate, which can better demonstrate the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the process of the present invention;

[0037] Figure 2 It is a schematic diagram for determining the weak area and the associated area of ​​the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] See also Figure 1 The present application provides a method for detecting the stability of a PET film, comprising the following steps:

[0041] S1. From the PET films to be tested, a group of products to be tested is selected, and the products to be tested are initially scanned by relevant high-definition equipment to determine the scanned images, and then the outer surfaces of the products to be tested are initially inspected based on the scanned images to identify whether there are defects on the outer surfaces. The high-definition equipment used is a high-pixel shooting device that can obtain high-definition images. Subsequently, based on the acquired high-definition images, it can be identified whether there are relevant defects on the outer surfaces. The so-called products to be tested are cut from the PET films by the operator. Since the PET films in this batch are relatively long, they cannot be tested in their entirety. Only a portion can be taken for testing to identify the relevant stability of the overall PET films. The specific method for the initial inspection is as follows:

[0042] S11, determining the overall area of ​​the display surface corresponding to the scanned image, and dividing the display surface into N micro-areas, where N is a preset value, the specific value of which is determined by the operator based on experience, and N is generally 4;

[0043] S12, marking a micro-area at the corner of the display surface as the initial area, starting from the initial area, comparing the initial area with other micro-areas, and confirming the comparison overlap degree BH i , where i represents different micro-regions:

[0044] If BH i All meet: BH i ≥90%, it means the alignment is correct and the correct signal is generated;

[0045] If BH i None: BH i ≥90%, then reselect a set of initial regions and compare the overlap results to meet BH i ≥90% of the micro-areas are marked as normal areas, and the coincidence comparison results do not meet the BH i ≥90% of the micro-areas are marked as abnormal areas. If the selected initial area is still in the state that does not meet the BH i ≥90%, the initial region is selected again. If all micro-regions are selected as the initial region and BH still occurs i If the error rate is ≥90%, an error signal is directly generated for display;

[0046] If BH i There exists a satisfying BH i ≥90% of the relevant micro-areas, the corresponding relevant micro-areas will be marked as normal areas, which will meet the BH i ≥90% of the relevant micro-areas were marked as abnormal areas;

[0047] S13, the external operator directly performs subsequent test analysis based on the correct signal generated and executes the analysis process of step S2, and performs on-site identification based on the error signal or abnormal area generated, assesses whether there are defects on the surface of the product to be tested, and decides whether to perform subsequent test analysis and execute the analysis process of step S2 (specifically, the error signal and the corresponding abnormal area will be displayed on the external display screen, and the operator needs to intervene manually based on the corresponding signal or the displayed abnormal area to assess the relevant abnormal situation and take corresponding inspection measures to identify whether there are cracks or bubbles or other situations);

[0048] Here, the film itself is compared, which is fully compatible with multiple films of different models or colors for testing, ensuring the comprehensiveness of the testing process. The comparison coincidence is the ratio of the same area of ​​the two to the area of ​​the same area. Since the areas of different areas are the same, the ratio of the overlapping area is the corresponding coincidence, which is very convenient for confirmation.

[0049] S2. Place the test object in the tensile instrument, clamp both sides of the test object, monitor the test object based on high-definition equipment, determine virtual feature points on the surface of the test object, perform a preliminary tensile test on the test object, identify whether the tensile test meets the standard, and then determine the weak area based on the change of the feature area between the feature points. The specific method of identifying whether the tensile test meets the standard includes:

[0050] S21, adjusting the internal distance of the stretching device so that the object to be tested is in a taut state, wherein the taut state is determined by the operator, and controlling the high-definition device to obtain a surface image of the object to be tested at the current moment;

[0051] S22, confirm the edge lines between the clamping parts on both sides of the relevant stretching equipment and the tested product, confirm the clamping image between the two groups of edge lines from the surface image, connect the center points of the two groups of edge lines, determine a group of center lines, and divide it into M groups of micro-line segments based on the distance length L of the center lines, wherein the distance of each group of micro-line segments is equal, and M is a preset value, the specific value of which is determined by the operator based on experience, and the segmentation points of adjacent micro-line segments and the selected center points are marked as feature points, and the longitudinal area between the feature points is the feature area (when determining the longitudinal area, the edge line is translated, and when the edge line intersects with the feature point, the area between the adjacent edge lines is the corresponding longitudinal area);

[0052] S23. Adjust the tension of the stretching instrument to a standard value, where the standard value is a preset value, and its specific value is determined by the operator based on experience, so that the clamps on both sides of the stretching instrument move away from each other synchronously, and their moving speed is consistent. When the clamps on both sides move to X1m, stop stretching, where X1 is a preset value. Based on the real-time monitoring results of the high-definition device, determine the length change between the feature points, and calibrate the distance between different adjacent feature points as L. k , where k represents different adjacent feature points and can also represent different feature areas;

[0053] S24, several groups L k Perform variance processing to determine the variance value Fc1. The specific method of performing variance processing is: k After the mean processing, the undetermined mean Jz is determined, k = 1, 2, ..., n is proposed, n represents the total number of feature areas, and the following is adopted: Confirm its variance value. Its variance can show the degree of dispersion of the corresponding value. The larger the degree of dispersion of the value, the more likely it is that there are several groups of L k The greater the difference, the less the stretching condition meets the standard. The variance value Fc1 is compared with the preset value Y1. When Fc1≥Y1, it means that the stretching test of the tested product does not meet the standard, and a stretching non-standard signal is generated for display. When Fc1<Y1, step S25 is executed.

[0054] S25, compare the variance value Fc1 with the preset value Y2. When Fc1>Y2, it means that there is a weak area and the weak area needs to be determined. Then, step S26 is executed, where Y2<Y1. When Fc≤Y2, a good product signal is generated, indicating that the test result of the product to be tested is better and the tensile test effect is better.

[0055] S26, from several groups L k Eliminate a group of maximum values, and then confirm the variance to get the variance value Fc2, and stop when the variance value Fc2 ≤ Y2. kThe relevant characteristic areas are marked as weak areas (weak areas are areas with longer stretching lengths. Under the same pulling force, some areas are stretched shorter and some areas are stretched longer. Therefore, those longer areas are relatively weak when pulled by the current pulling force, so they will be pulled longer. Subsequent analysis is required to re-analyze the weak areas. Here, a group of maximum values ​​are preferentially eliminated. When the confirmed variance meets the corresponding evaluation conditions, the characteristic area corresponding to the maximum value is marked as a weak area. If it still does not meet the conditions, another group of maximum values ​​is eliminated until all conditions are met. Then, the weak areas can be confirmed one by one. In order to identify the thickness changes of the weak areas, the thickness parameters are tested to conduct one-to-one analysis to confirm the total proportion of the weak areas inside the corresponding tested product, so as to evaluate the relevant stability performance of the tested product);

[0056] S3. Based on the confirmed weak area, select the associated area of ​​the weak area from other surrounding characteristic areas, and use relevant equipment to determine the thickness parameters of the associated area and the weak area, and identify the real weak area based on the display of the thickness parameters. The relevant equipment can be a film thickness meter, a spectroscopic reflectometer, an optical profiler and other related instruments that can test the thickness of the film, and the specific selection is determined by the operator;

[0057] Among them, combined Figure 2 , the specific method of identification is:

[0058] S31, based on the determined weak area, identify whether there is a weak area in the adjacent characteristic areas around the weak area. If not, mark the two groups of characteristic areas adjacent to the weak area as associated areas. If so, treat the weak area and the adjacent weak areas as a whole weak area, and determine the associated areas in the same way (that is, if the weak areas appear continuously, the surrounding weak areas and the weak area are treated as a whole weak area, and then the surrounding related confirmation is performed, and so on);

[0059] S32, using relevant equipment to confirm the thickness data of the associated area and the weak area in the middle one by one (through scanning, the scanning is a group of scanning lines, which can cover the entire test product, and the thickness on a corresponding line can be confirmed. Because the force is uniform, the thickness data of each line is basically consistent, and the equipment can automatically output the thickness data of the corresponding line), starting from one side line of one group of associated areas to the other side line of another group of associated areas, the confirmed thickness data are arranged one by one to generate a thickness sequence {H1, H2, ..., Hm};

[0060] S33, starting from the first set of parameters H1 of the thickness sequence, confirm the difference between H1 and H2, where the difference is greater than 0:

[0061] If the difference is less than Y3, where Y3 is a preset value, and its specific value is determined by the operator based on experience, H1 and H2 are classified as the same value, and then the difference between H2 and H3 is determined. If the difference is less than Y3, H1, H2 and H3 are all classified as the same value. j With H j+1 When the difference between the two is ≥Y3, the parameter sequence {H1, ..., H j} are divided into similar values, and then from H j+1 At the beginning, the differences between the adjacent parameters are confirmed one by one, and so on, several groups of parameter sequences are confirmed;

[0062] If the difference is ≥ Y3, start from H2 and mark H1 as an outlier, determine the difference between H2 and H3, and if the difference is < Y3, classify H1, H2 and H3 as the same type. j With H j+1 When the difference between the two is ≥Y3, the parameter sequence {H1, ..., H j} are divided into similar values, and then from H j+1 At the beginning, the differences between the adjacent parameters are confirmed in turn, and so on, to confirm several groups of parameter sequences. For example: the parameter sequence is {1, 0.9, 0.8, 0.75, 0.55, 0.4, 0.35, 0.45, 0.75, 0.8, 0.9, 0.99}. Assuming that the determined Y3 is 1.1, after processing, the differences between the adjacent parameters of 1, 0.9, 0.8, and 0.75 meet the evaluation conditions, so they belong to a parameter sequence. 0.55 does not meet the conditions when pushed forward or backward, so 0.55 is an abnormal value, and the subsequent 0.4, 0.35, and 0.45 belong to a parameter sequence, and 0.75, 0.8, 0.9, and 0.99 also belong to a parameter sequence.

[0063] S34, perform mean processing on the thickness data within each parameter sequence to determine the pending mean value Jq, where q represents different parameter sequences. When the pending mean value Jq < Y4, the scanning area corresponding to the corresponding parameter sequence is calibrated as the real weak area, otherwise, no calibration is performed; specifically, the real weak area determined at this time has a relevant change in position compared with the original weak area. The area determined at this time is the most accurate area, that is, the area with the most balanced thickness value, and also the weakest and most accurate area. Based on the determination of this area, the final stability parameter can be identified to ensure the accuracy of the stability parameter;

[0064] S4. Based on the specific area ratio of the real weak area, identify and display the stability parameters of the product to be tested. The specific method is as follows:

[0065] Based on the total area value MM of several real weak areas (several here include one), the area value LM of the corresponding clamped image after being stretched is confirmed;

[0066] Use MM÷LM=ZB to confirm the specific area ratio ZB;

[0067] The stability parameter WD is determined using WD=1-ZB and displayed for external personnel to confirm. The smaller the specific area ratio ZB, the larger the generated stability parameter WD will be, which can fully demonstrate the relevant stability performance of the product to be tested. By confirming the real weak area, the confirmed value is more accurate and can better demonstrate its test accuracy.

[0068] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0069] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for detecting the stability of a PET film, characterized in that: The following steps are involved: S1. Select a group of test products from the PET films to be tested, and use relevant high-definition equipment to perform a preliminary scan on the test products to determine the scanned image, and then perform a preliminary inspection on the outer surface of the test products based on the scanned image to identify whether there are defects on the outer surface; S2. Place the object to be tested in the tensile instrument. After clamping both sides of the object to be tested, perform relevant monitoring on the object to be tested based on high-definition equipment, determine virtual feature points on the surface of the object to be tested, perform preliminary tensile testing on the object to be tested, identify whether the tensile test meets the standard, and then determine the weak area based on the changes in the feature areas between the feature points, including: S21, adjusting the internal distance of the stretching device so that the object to be tested is in a taut state, wherein the taut state is determined by the operator, and controlling the high-definition device to obtain a surface image of the object to be tested at the current moment; S22, confirming the edge lines between the clamping parts on both sides of the relevant stretching equipment and the tested product, confirming the clamping image between the two groups of edge lines from the surface image, connecting the center points of the two groups of edge lines, determining a group of center lines, and dividing them into M groups of micro-line segments based on the distance length L of the center lines, wherein the distance of each group of micro-line segments is equal, and M is a preset value, marking the segmentation points of adjacent micro-line segments and the selected center points as feature points, and the longitudinal area between the feature points as the feature area; S23, adjust the tension of the stretching instrument to a standard value, where the standard value is a preset value, so that the clamps on both sides of the stretching instrument move away synchronously at a consistent moving rate. When the clamps on both sides move to X1 m, stop stretching, where X1 is a preset value. Based on the real-time monitoring results of the high-definition device, determine the length change between the feature points, and calibrate the distance between different adjacent feature points as L k , where k represents different adjacent feature points or different feature areas; S24, several groups of L k Perform variance processing to determine the variance value Fc1, and compare the variance value Fc1 with the preset value Y1: when Fc1≥Y1, it means that the tensile test of the tested product does not meet the standard, and a tensile failure signal is generated for display; when Fc1<Y1, execute step S25; S25, compare the variance value Fc1 with the preset value Y2. When Fc1>Y2, it means there is a weak area, and the weak area needs to be determined. Then, step S26 is executed, where Y2<Y1. When Fc1≤Y2, a superior signal is generated. S26, from several groups L k Eliminate a group of maximum values, and then confirm the variance to obtain the variance value Fc2, and stop when the variance value Fc2 ≤ Y2. k The relevant characteristic areas are marked as weak areas; S3. Based on the confirmed weak area, select the associated area of ​​the weak area from other surrounding characteristic areas, and use relevant equipment to determine the thickness parameters of the associated area and the weak area, and identify the real weak area based on the display of the thickness parameters. The specific method is as follows: S31, based on the determined weak area, identifying whether there is a weak area in the adjacent characteristic areas around the weak area, if not, marking the two groups of characteristic areas adjacent to the weak area as associated areas, if yes, treating the weak area and the adjacent weak areas as a whole weak area, and determining the associated areas in the same way; S32, using relevant equipment to confirm the thickness data of the associated areas and the weak areas in the middle one by one, starting from one side line of one group of associated areas to the other side line of another group of associated areas, arranging the confirmed thickness data one by one to generate a thickness sequence {H1, H2, ..., Hm}; S33, starting from the first set of parameters H1 of the thickness sequence, confirm the difference between H1 and H2, where the difference is greater than 0: If the difference is less than Y3, where Y3 is a preset value, H1 and H2 are classified as the same type of values, and then the difference between H2 and H3 is determined. If the difference is less than Y3, H1, H2 and H3 are all classified as the same type of values. j With H j+1 When the difference between the two is ≥Y3, the parameter sequence {H1, ..., H j } are divided into similar values, and then from H j+1 At the beginning, the differences between the adjacent parameters are confirmed one by one, and so on, several groups of parameter sequences are confirmed; If the difference is ≥ Y3, start from H2 and mark H1 as an outlier, determine the difference between H2 and H3, and if the difference is < Y3, classify H1, H2 and H3 as the same type. j With H j+1 When the difference between the two is ≥Y3, the parameter sequence {H1, ..., H j } are divided into similar values, and then from H j+1 At the beginning, the differences between the adjacent parameters are confirmed one by one, and so on, several groups of parameter sequences are confirmed; S34, performing mean processing on the thickness data within each parameter sequence to determine a pending mean value Jq, where q represents different parameter sequences, and when the pending mean value Jq < Y4, calibrating the scanning area corresponding to the corresponding parameter sequence as a true weak area; S4. Based on the specific area ratio of the real weak area, identify and display the stability parameters of the product to be tested.

2. A method for detecting the stability of a PET film according to claim 1, characterized in that: In step S1, the specific method of performing the initial inspection on the outer surface of the test object is: S11, determining the overall area of ​​the display surface corresponding to the scanned image, and dividing the display surface into N micro-areas of micro-area, where N is a preset value; S12, marking a micro-area at the corner of the display surface as the initial area, starting from the initial area, comparing the initial area with other micro-areas, and confirming the comparison overlap degree BH i , where i represents different micro-regions: If BH i All meet: BH i ≥90%, it means the alignment is correct and the correct signal is generated; If BH i None: BH i ≥90%, then reselect a set of initial regions and compare the overlap results to meet BH i ≥90% of the micro-areas are marked as normal areas, and the coincidence comparison results do not meet the BH i ≥90% of the micro-areas are marked as abnormal areas. If the selected initial area is still in the state that does not meet the BH i ≥90%, the initial region is selected again. If all micro-regions are selected as the initial region and BH still occurs i If the error rate is ≥90%, an error signal is directly generated for display; If BH i There exists a satisfying BH i ≥90% of the relevant micro-areas, the corresponding relevant micro-areas will be marked as normal areas, which will meet the BH i ≥90% of the relevant micro-areas were marked as abnormal areas; S13. The external operator directly performs subsequent test analysis based on the correct signal generated and executes the analysis process of step S2. Based on the error signal or abnormal area generated, the operator performs on-site identification to assess whether there are defects on the surface of the product to be tested, and decides whether to perform subsequent test analysis and execute the analysis process of step S2.

3. A method for detecting the stability of a PET film according to claim 1, characterized in that: In the step S33, when the to-be-determined mean value Jq≥Y4, no calibration is performed.

4. The method for detecting the stability of a PET film according to claim 1, characterized in that: In step S4, the specific method of determining the stability parameter is: Based on the total area value MM of several real weak areas, where several includes one, the area value LM of the corresponding clamped image after being stretched is confirmed; Use MM÷LM=ZB to confirm the specific area ratio ZB; The stability parameter WD is determined using WD=1-ZB and displayed.

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