CN116973367B - Method for inspecting degradation defect position of biodegradable film - Google Patents

Method for inspecting degradation defect position of biodegradable film Download PDF

Info

Publication number
CN116973367B
CN116973367B CN202310822116.2A CN202310822116A CN116973367B CN 116973367 B CN116973367 B CN 116973367B CN 202310822116 A CN202310822116 A CN 202310822116A CN 116973367 B CN116973367 B CN 116973367B
Authority
CN
China
Prior art keywords
area
stress
point
biodegradable
image
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202310822116.2A
Other languages
Chinese (zh)
Other versions
CN116973367A (en
Inventor
王洪琼
孙琪
王洪晓
林李华
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Huifa Plastic Industry Technology Co ltd
Original Assignee
Guangdong Huifa Plastic Industry Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong Huifa Plastic Industry Technology Co ltd filed Critical Guangdong Huifa Plastic Industry Technology Co ltd
Priority to CN202310822116.2A priority Critical patent/CN116973367B/en
Publication of CN116973367A publication Critical patent/CN116973367A/en
Application granted granted Critical
Publication of CN116973367B publication Critical patent/CN116973367B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/0002—Inspection of images, e.g. flaw detection
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/10—Segmentation; Edge detection
    • G06T7/12—Edge-based segmentation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/10—Segmentation; Edge detection
    • G06T7/13—Edge detection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
    • G01N2021/8854—Grading and classifying of flaws
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
    • G01N2021/8854—Grading and classifying of flaws
    • G01N2021/8867—Grading and classifying of flaws using sequentially two or more inspection runs, e.g. coarse and fine, or detecting then analysing
    • G01N2021/887—Grading and classifying of flaws using sequentially two or more inspection runs, e.g. coarse and fine, or detecting then analysing the measurements made in two or more directions, angles, positions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
    • G01N2021/8854—Grading and classifying of flaws
    • G01N2021/888—Marking defects

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Biochemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Quality & Reliability (AREA)
  • Signal Processing (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

The invention belongs to the technical field of biodegradable film detection, and provides a method for detecting the position of a degradation defect of a biodegradable film, which comprises the steps of obtaining an image of the biodegradable film as an image to be detected; graying the image to be detected to obtain a gray image; dividing a gray image into a plurality of subintervals by edge lines of the gray image obtained through edge detection; distinguishing a source stress area and a stressed area in each subarea; extracting a visualization region in the sub-region according to the source stress region and the stressed region; the corresponding positions of the respective visualization areas on the biodegradable film where stress whitening exists are marked. The invention can accurately identify and detect the linear fine linear stress crack area which is expanded along with degradation on the biodegradable mulch film, and can clearly mark all the positions which gradually lose local refractive index along with degradation in the developed area of the biodegradable mulch film after development.

Description

Method for inspecting degradation defect position of biodegradable film
Technical Field
The invention belongs to the technical field of biodegradable film detection, and particularly relates to a degradation defect position detection method of a biodegradable film.
Background
In the preparation process of the biodegradable mulching film, if polylactic acid PLA is used alone for preparation, the degradation process of the biodegradable mulching film is prolonged due to the hydrophobicity of PLA molecules, and in actual processing, PLA and other biodegradable materials are often required to be blended so as to carry out modification treatment on the hydrophobicity of the biodegradable mulching film to improve the degradation speed, and the blend can greatly improve the degradation rate of the blend due to the common blending of polylactic acid PLA and cellulose or starch.
For example, chinese patent with application number CN202211077988.2 discloses a biodegradable multi-layer structure polylactic acid barrier film and a preparation method thereof, wherein a CDA-g-PDLA graft copolymer is obtained by grafting D-lactide and cellulose diacetate, and then the multi-layer structure barrier film is prepared by taking polylactic acid PLA and CDA-g-PDLA as raw materials, which has the characteristics of excellent barrier property and high strength; however, in blending PLA with cellulose or starch, the transition is gradually made from brittle materials to tough materials (see references Zhang Kunyu, wu Hang, zhuang Yugang, etc. polylactic acid/starch-based thermoplastic elastomer blends have been studied in mechanical properties [ C ]// national institute of Polymer science 2005. 2005), a large number of micro-voids are inevitably generated in the blended materials, so that regions near the micro-voids during the later pulling process of producing a stretched film or blown film are difficult to distinguish and identify by the naked eye due to the stress areas of the stress whitening phenomenon generated in the produced biodegradable mulch by necking (phenomenon of local cross-section reduction of the material) or Bauschinger effect, etc., the local refractive indexes of these stress areas are changed, so that the local light transmittance of the biodegradable mulch is affected, and since most of the biodegradable mulch is in a transparent state, some of the stress areas are not diffusion-affected with the degradation process of the biodegradable film.
Disclosure of Invention
The invention aims to provide a degradation defect position inspection method of a biodegradable film, which solves one or more technical problems in the prior art and at least provides a beneficial selection or creation condition.
In order to achieve the above object, according to an aspect of the present invention, there is provided a degradation defect position inspection method of a biodegradable film, the method comprising the steps of:
s100, acquiring an image of a biodegradable film as an image to be detected;
s200, graying an image to be detected to obtain a gray image;
s300, dividing the gray image into a plurality of subintervals through edge lines of the gray image obtained through edge detection;
s400, distinguishing a source stress area and a stressed area in each subarea;
s500, extracting a visualization area in the subarea according to the source stress area and the stressed area;
s600, marking the corresponding positions of the visualization areas with stress whitening on the biodegradable film.
Further, in S100, the method for acquiring the image of the biodegradable film as the image to be detected includes: the lower surface of the biodegradable mulching film is irradiated by an LED lamp or a UV lamp, and the upper surface of the biodegradable mulching film is scanned by a CCD industrial camera to obtain an image of the biodegradable mulching film as an image to be detected.
Preferably, the CCD industrial camera is a MV-VD series high-speed industrial digital camera.
Preferably, the UV lamp is a Hanovia ultraviolet lamp, which ultraviolet sterilizes the biodegradable mulch while acquiring an image of the biodegradable mulch.
Preferably, the biodegradable mulching film is pulled and driven by a pulling roll while the image of the biodegradable mulching film is obtained as an image to be detected.
Further, in S300, the method of edge detection is: sobel edge detection or Canny edge detection.
The local light transmittance of the biodegradable mulching film is influenced by the stressed area generating the stress whitening phenomenon, so that gray level difference exists among all subintervals segmented on a gray level image, the difference is not obvious, especially, a fine linear crack area represented by the stress direction of the stressed area is shown as weak in the subintervals on the gray level image compared with other areas, although a part of obvious areas can be identified manually, the false detection rate and the omission rate of manual sampling detection are extremely high due to the fact that the areas are not obvious, and most of the areas with fine linear stress cracks which are linear cannot be identified manually; the crack areas gradually increase along with degradation of the biodegradable mulch film, the local light transmittance of the crack areas is greatly reduced along with the degradation of the biodegradable mulch film in middle and later periods of actual use, the actual use effect of the biodegradable mulch film in middle and later periods of degradation is seriously affected, normal non-stress whitening areas such as folds and wrinkles of the film are not areas caused by stress reasons, the areas are not expanded along with degradation in subsequent use, the refractive index of light rays is relatively stable, the actual use is not affected, and in order to identify and distinguish the linear fine linear stress crack areas which are expanded along with degradation on the biodegradable mulch film, the invention provides the following methods:
further, in S400, the method for distinguishing the source stress region from the stressed region in each sub-region includes:
the method comprises the steps of arranging all subareas from small to large according to the area of the subareas to form a set VK, taking the VK (i) as an ith subarea in the set VK, and sequentially carrying out stress direction adjustment processing on all the VK (i), wherein the stress direction adjustment processing specifically comprises the following steps:
performing corner detection on the VK (i) to obtain a corner point of the VK (i), taking a point with the smallest gray value in the VK (i) as a point SL, obtaining a point with the largest difference value between the gray value in each corner point of the VK (i) and the gray value of PL as a point SMAx1, obtaining a point with the largest difference value between the gray value in each corner point of the VK (i) and the gray value of PL as a point SMin1, obtaining a point with the smallest difference value between the gray value in each corner point of the VK (i) and the gray value of SMAx1 as a point SMAx2, and obtaining a point with the smallest difference value between the gray value in each corner point of the VK (i) and the gray value of SMin1 as a point SMin2; the circumscribed circle of the triangle formed by the three points of SMAx1, SMin1 and SMAx2 is CYC1; the circumscribed circle of the triangle formed by the three points of SMAx1, SMin1 and SMin2 is CYC2; (in a stress whitening region caused by a stress region with a high probability, the positions of damage caused by the stress and gray values have strong relevance, the larger the damage is, the smaller the gray values are, points SMax1 to SMin1 represent linear lines of which local refractive indexes are changed from large to small due to the stress, and CYC1 and CYC2 represent the maximum influence range of points SMax1 and SMin1 on the linear lines along with degradation);
the source stress region and the stressed region in CYC1 and CYC2 are distinguished, and specifically are:
if the average gray value of the pixel points in CYC1 is smaller than the average gray value of the pixel points in CYC2, the direction from the circle center of CYC1 to the circle center of CYC2 is recorded as stress direction, CYC1 is used as a source stress area, and CYC2 is used as a stressed area; otherwise, the direction from the circle center of CYC2 to the circle center of CYC1 is recorded as stress direction, CYC1 is a stressed area, and CYC2 is a source stress area;
the stress direction provided by the method is the direction of the crack change along with the stress of the site with the most remarkable gray value, namely the stress direction is the direction along with the expansion of the stressed area of the biodegradable mulching film along with the degradation, the starting position of the stress direction is the current crack position, and the stressed area of the stress direction is the position which can be slowly eroded along with the degradation process; the stressed area and the source stress area respectively represent the position of slow erosion in the degradation process of stress pointing and the initial position of crack before degradation; however, simply judging the gray value can make the selected areas of the biodegradable mulch film which are not seriously whitened by subsequent stress and are caused by film reflection, so the method is proposed to screen according to the stress direction degree to further improve the screening accuracy of the stressed areas, and avoid selecting the error areas:
preferably, the method for distinguishing the source stress region and the stressed region in the CYC1 and the CYC2 is specifically as follows:
the stress directivities of CYC1 and CYC2 are calculated respectively, and the calculation formulas of the stress directivities Str (CYC 1) and Str (CYC 2) corresponding to CYC1 and CYC2 are as follows:
wherein, cir (CYC 1) and cir (CYC 2) respectively represent the number of pixel points on the circles of CYC1 and CYC2, x and y are accumulated variables, G (x) represents the xth gray value on the circle of CYC1, G (y) represents the yth gray value on the circle of CYC2, the gray values of the stress points of the CYC1 and the CYC2 are respectively expressed, and the gray values are expressed in the meaning of the gray of the position with the highest probability of being stressed along with degradation in the range of the influence area of the stress of the CYC1 and the CYC2; gMin () is a function taking the gray value as the minimum value;
if Str (CYC 1) is more than or equal to Str (CYC 2), the direction from the circle center of the CYC1 to the circle center of the CYC2 is recorded as stress direction, the CYC1 is a source stress area, and the CYC2 is a stressed area; otherwise, if Str (CYC 1) < Str (CYC 2), the direction from the center of CYC2 to the center of CYC1 is noted as stress direction, CYC1 as stressed region, CYC2 as source stress region.
Further, in S500, the method for extracting the visualization area in the sub-area according to the source stress area and the stressed area includes:
the outer common tangent lines of CYC1 and CYC2 are L1 and L2 respectively, and the region between the CYC1, CYC2 and the outer common tangent lines L1 and L2 is taken as the region Area1 to be displayed; (the region Area1 to be displayed has a high probability of being a stressed region in the degradation process, and stress whitening gradually occurs due to the action of stress, so that the local refractive index of the stressed region can be influenced); the Area1 to be visualized is subjected to the visualization treatment as a visualization Area, and the visualization treatment specifically comprises the following steps:
taking a connecting line of CYC1 and CYC2 as LC, and the length of the LC is LCD;
the source stress Area in the Area to be displayed Area1 is CYCGet, the stress Area in the Area to be displayed Area1 is CYCREC, CYCREC (j 1) is the j1 th pixel point in the CYCREC, and j1 is the serial number of the pixel point in the CYCREC; all CYCREC (j 1) are subjected to the following visualization treatment within the value range of j 1: taking the point of the CYCREC (j 1) along the reverse direction of stress pointing and with the distance of the LCD position as PJ, taking the average gray value of all pixel points with the gray value larger than PJ as GV in the CYCGet, and replacing the gray value of the CYCREC (j 1) with the value of GV;
filling the gray values of all the pixel points except for CYCGet and CYCREC in the region Area1 to be displayed with the gray values of all the pixel points in CYCREC;
the region to be visualized Area1 is designated as a visualization region.
The beneficial effects are as follows: all positions, which are changed along with the gradual loss of local refractive index in the degradation process, of the developed areas of the biodegradable film can be clearly marked, and the positions are linear fine linear stress crack areas which are expanded along with degradation on the biodegradable film.
Further, in S600, the method of marking the corresponding positions of the respective developed areas on the biodegradable film where stress whitening exists includes: if the average gray value of the pixel points in the display area is larger than the average gray value of the pixel points in the gray image, judging that stress whitening exists in the display area, and marking the corresponding positions of the display areas with the stress whitening on the biodegradable film.
Note that: the stress whitening of the visualization area is not a traditional visible stress whitening area, but is predicted according to the stress direction and the strength change, and the stress whitening area which is predicted to be generated with high probability along with the change of the stress in the future degradation process can cause the local refractive index to change.
The beneficial effects of the invention are as follows: the invention can accurately identify and detect the linear fine linear stress crack area which can be expanded along with degradation on the biodegradable mulch film, and can clearly mark all the positions which gradually lose local refractive index along with degradation in the developed area of the biodegradable mulch film after development, thereby accurately screening the biodegradable film which is not easy to change along with the local refractive index along with degradation.
Drawings
The above and other features of the present invention will become more apparent from the detailed description of the embodiments thereof given in conjunction with the accompanying drawings, in which like reference characters designate like or similar elements, and it is apparent that the drawings in the following description are merely some examples of the present invention, and other drawings may be obtained from these drawings without inventive effort to those of ordinary skill in the art, in which:
FIG. 1 is a flow chart showing a method for inspecting the position of degradation defect of a biodegradable film.
Detailed Description
The conception, specific structure, and technical effects produced by the present invention will be clearly and completely described below with reference to the embodiments and the drawings to fully understand the objects, aspects, and effects of the present invention. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.
Firstly, preparing a film, wherein the method for preparing the film comprises the following steps:
(1) Weighing D-lactide and CDA with the mass ratio of 7/3, drying in a vacuum drying oven at 60 ℃, heating a reaction kettle to 110 ℃, placing the dried CDA and D-lactide in the reaction kettle, and stirring and dissolving under the protection of nitrogen after three gas displacement is completed.
(2) Adding 4% of Sn (Oct) in total mass fraction into the mixture obtained in the step (1) 2 And (3) continuously stirring the catalyst under the protection of nitrogen, stopping heating after the reaction time is reached, and taking out the solid reaction product after the reaction kettle is cooled to room temperature.
(3) Dissolving the solid reactant obtained in the step (2) in chloroform, and stirring and dissolving for 24 hours by using a magnetic stirrer until the dissolution is complete. Slowly pouring the obtained solution into absolute methanol for precipitation, filtering, and then placing the solid product into a vacuum drying box for vacuum drying to obtain a light yellow solid crude product.
(4) And (3) taking toluene as a solvent, placing the solid crude product in a Soxhlet extractor, refluxing for 24 hours, and drying to obtain the CDA-g-PDLA grafted copolymer.
(5) And (3) dissolving the CDA-g-PDLA obtained in the step (4) in a CHL/DMF mixed solvent with the mass ratio of 9/1 to prepare a solution with 15%wt, and dissolving the PLLA in the CHL/DMF mixed solvent with the mass ratio of 9/1 to prepare a solution with 13%wt.
(6) And (3) scraping a film on the glass plate by using the PLLA solution obtained in the step (5), and scraping the film again on the basis of the PLLA film after the PLLA film is dried and formed by using the CDA-g-PDLA solution to form a film with a double-layer structure.
(7) And (3) repeating the step (6) again on the basis of the PLLA and CDA-g-PDLA bilayer structure membrane obtained in the step (6) to obtain the polylactic acid barrier membrane with a four-layer structure as a biodegradable membrane.
Example 1:
referring to fig. 1, which is a flowchart illustrating a method for inspecting the position of a degradation defect of a biodegradable film, a method for inspecting the position of a degradation defect of a biodegradable film according to an embodiment of the present invention will be described with reference to fig. 1, and comprises the steps of:
s100, acquiring an image of a biodegradable film as an image to be detected;
s200, graying an image to be detected to obtain a gray image;
s300, dividing the gray image into a plurality of subintervals through edge lines of the gray image obtained through edge detection;
s400, distinguishing a source stress area and a stressed area in each subarea;
s500, extracting a visualization area in the subarea according to the source stress area and the stressed area;
s600, marking the corresponding positions of the visualization areas with stress whitening on the biodegradable film.
Further, in S100, the method for acquiring the image of the biodegradable film as the image to be detected includes: the lower surface of the biodegradable mulching film is irradiated by an LED lamp, and the upper surface of the biodegradable mulching film is scanned by a CCD industrial camera to obtain an image of the biodegradable mulching film as an image to be detected.
Preferably, the CCD industrial camera is a MV-VD series high-speed industrial digital camera.
Preferably, the biodegradable mulching film is pulled and driven by a pulling roll while the image of the biodegradable mulching film is obtained as an image to be detected.
In S300, the edge detection method is Sobel edge detection.
Further, in S400, the method for distinguishing the source stress region from the stressed region in each sub-region includes:
the number of the memory regions is N, the regions are arranged from small to large according to the area of the regions to form a set VK, the VK (i) is taken as the ith region in the set VK, and stress direction adjustment processing is sequentially carried out on the VK (i), specifically:
performing corner detection on the VK (i) to obtain a corner point of the VK (i), taking a point with the smallest gray value in the VK (i) as a point SL, obtaining a point with the largest difference value between the gray value in each corner point of the VK (i) and the gray value of PL as a point SMAx1, obtaining a point with the largest difference value between the gray value in each corner point of the VK (i) and the gray value of PL as a point SMin1, obtaining a point with the smallest difference value between the gray value in each corner point of the VK (i) and the gray value of SMAx1 as a point SMAx2, and obtaining a point with the smallest difference value between the gray value in each corner point of the VK (i) and the gray value of SMin1 as a point SMin2; the circumscribed circle of the triangle formed by the three points of SMAx1, SMin1 and SMAx2 is CYC1; the circumscribed circle of the triangle formed by the three points of SMAx1, SMin1 and SMin2 is CYC2;
the source stress region and the stressed region in CYC1 and CYC2 are distinguished, and specifically are:
if the average gray value of the pixel points in CYC1 is smaller than the average gray value of the pixel points in CYC2, the direction from the circle center of CYC1 to the circle center of CYC2 is recorded as stress direction, CYC1 is used as a source stress area, and CYC2 is used as a stressed area; otherwise, the direction from the circle center of CYC2 to the circle center of CYC1 is recorded as stress direction, CYC1 is a stressed area, and CYC2 is a source stress area;
further, in S500, the method for extracting the visualization area in the sub-area according to the source stress area and the stressed area includes:
the outer common tangent lines of CYC1 and CYC2 are L1 and L2 respectively, and the region between the CYC1, CYC2 and the outer common tangent lines L1 and L2 is taken as the region Area1 to be displayed; the Area1 to be visualized is subjected to the visualization treatment as a visualization Area, and the visualization treatment specifically comprises the following steps:
the connecting line of CYC1 and CYC2 is LC, and the LC length is LCD;
the source stress Area in the Area to be displayed Area1 is CYCGet, the stress Area in the Area to be displayed Area1 is CYCREC, CYCREC (j 1) is the j1 th pixel point in the CYCREC, and j1 is the serial number of the pixel point in the CYCREC; all CYCREC (j 1) are subjected to the following visualization treatment within the value range of j 1: taking the point of the CYCREC (j 1) along the reverse direction of stress pointing and with the distance of the LCD position as PJ, taking the average gray value of all pixel points with the gray value larger than PJ as GV in the CYCGet, and replacing the gray value of the CYCREC (j 1) with the value of GV;
filling the gray values of all the pixel points except for CYCGet and CYCREC in the region Area1 to be displayed with the gray values of all the pixel points in CYCREC;
the region to be visualized Area1 is designated as a visualization region.
Further, in S600, the method of marking the corresponding positions of the respective developed areas on the biodegradable film where stress whitening exists includes: if the average gray value of the pixel points in the display area is larger than the average gray value of the pixel points in the gray image, judging that stress whitening exists in the display area, and marking the corresponding positions of the display areas with the stress whitening on the biodegradable film.
Preferably, the corresponding position of each marked visualization area with stress whitening on the biodegradable film is a degradation defect position, when the ratio of the total area of the degradation defect position on the biodegradable film is larger than a preset proportion, the biodegradable film is judged to be an unqualified product, otherwise, the biodegradable film is judged to be a qualified product, and the preset proportion is set to be 5% of the total area of the biodegradable film.
Example 2:
the method of distinguishing between source and stressed regions in CYC1 and CYC2 in example 1 was replaced with:
the stress directivities of CYC1 and CYC2 are calculated respectively, and the calculation formulas of the stress directivities Str (CYC 1) and Str (CYC 2) corresponding to CYC1 and CYC2 are as follows:
wherein, cir (CYC 1) and cir (CYC 2) respectively represent the number of pixel points on the circles of CYC1 and CYC2, x and y are accumulated variables, G (x) represents the xth gray value on the circle of CYC1, G (y) represents the yth gray value on the circle of CYC2, the gray values of the stress points of the CYC1 and the CYC2 are respectively expressed, and the gray values are expressed in the meaning of the gray of the position with the highest probability of being stressed along with degradation in the range of the influence area of the stress of the CYC1 and the CYC2; gMin () is a function taking the gray value as the minimum value;
if Str (CYC 1) is more than or equal to Str (CYC 2), the direction from the circle center of the CYC1 to the circle center of the CYC2 is recorded as stress direction, the CYC1 is a source stress area, and the CYC2 is a stressed area; otherwise, if Str (CYC 1) < Str (CYC 2), the direction from the center of CYC2 to the center of CYC1 is noted as stress direction, CYC1 as stressed region, CYC2 as source stress region.
Comparative example:
and conveying the prepared film into a stretching system, lifting the film by using each traction roller in the stretching system, and carrying out heat setting and cold setting on the stretched film, so as to obtain the biodegradable film after corona treatment.
The stretching system comprises 2 traction rollers which rotate in the same direction and are arranged side by side, the rotating speed of the latter traction roller is 1.1 times that of the former traction roller, the rotating speed of the first traction roller is 5RPM, and the gap between two adjacent traction rollers is 20mm.
Screening out the prepared films, wherein the total area of stress-whitening subintervals on all the biodegradable films (checked as qualified products) screened out by the degradation defect position checking method of the biodegradable films according to the embodiment 1 and the embodiment 2 is less than 5% of the total area of the biodegradable films, 30 rolls of the biodegradable films with the length of 10 meters are respectively taken out, and 30 rolls of the biodegradable films with the width of 1.5 meters and the length of 10 meters prepared by the comparative example are taken out;
after all the biodegradable films are laid in a natural environment with the temperature range of 10 ℃ to 30 ℃ and naturally degraded for 3 months, acquiring images of the upper surface of the biodegradable films by a CCD industrial camera, irradiating the lower part of the biodegradable films by LED light when acquiring the images, graying the images of the upper surface of the biodegradable films, and dividing the gray images into a plurality of subintervals by Sobel edge lines for acquiring the gray images by Sobel edge detection; if the average gray value of the pixel points in the subinterval is larger than the average gray value of the pixel points in the gray image, marking the subinterval as stress whitening; the total area of the subintervals of stress whitening on all the biodegradable films is less than 5% of the total area of the biodegradable films when the biodegradable films are paved;
tested:
of the 30 rolls of biodegradable films in example 1, the number of the subintervals of stress whitening having a total area of more than 20% of the total area of the biodegradable film after 3 months of natural degradation was 4 rolls;
in 30 rolls of biodegradable film in example 2, the number of subintervals with a total area of stress whitening of more than 20% of the total area of the biodegradable film after 3 months of natural degradation was 2 rolls;
in 30 rolls of the biodegradable film in the comparative example, after 3 months of natural degradation, the number of subintervals in which stress is whitened is 8 rolls, the total area of which is greater than 20% of the total area of the biodegradable film.
Therefore, the qualified products screened by the method can accurately screen the biodegradable film with the partial refractive index not easy to change along with the degradation process, and the qualified products can reduce the occurrence probability of the stress whitening area in the degradation process of the biodegradable film.
Although the present invention has been described in considerable detail and with particularity with respect to several described embodiments, it is not intended to be limited to any such detail or embodiment or any particular embodiment so as to effectively cover the intended scope of the invention. Furthermore, while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Furthermore, the foregoing description of the invention has been presented in its embodiments contemplated by the inventors for the purpose of providing a useful description, and for the purposes of providing a non-essential modification of the invention that may not be presently contemplated, may represent an equivalent modification of the invention.

Claims (2)

1. A method for inspecting the position of degradation defect of a biodegradable film, comprising the steps of:
s100, acquiring an image of a biodegradable film as an image to be detected;
s200, graying an image to be detected to obtain a gray image;
s300, dividing the gray image into a plurality of subintervals through edge lines of the gray image obtained through edge detection;
s400, distinguishing a source stress area and a stressed area in each subarea;
s500, extracting a visualization area in the subarea according to the source stress area and the stressed area;
s600, marking the corresponding positions of the visualization areas with stress whitening on the biodegradable film;
specifically, in S400, the method for distinguishing the source stress region from the stressed region in each sub-region includes:
the method comprises the steps of arranging all subareas from small to large according to the area of the subareas to form a set VK, taking the VK (i) as an ith subarea in the set VK, and sequentially carrying out stress direction adjustment processing on all the VK (i), wherein the stress direction adjustment processing specifically comprises the following steps:
performing corner detection on the VK (i) to obtain a corner point of the VK (i), taking a point with the smallest gray value in the VK (i) as a point SL, obtaining a point with the largest difference value between the gray value in each corner point of the VK (i) and the gray value of PL as a point SMAx1, obtaining a point with the largest difference value between the gray value in each corner point of the VK (i) and the gray value of PL as a point SMin1, obtaining a point with the smallest difference value between the gray value in each corner point of the VK (i) and the gray value of SMAx1 as a point SMAx2, and obtaining a point with the smallest difference value between the gray value in each corner point of the VK (i) and the gray value of SMin1 as a point SMin2; the circumscribed circle of the triangle formed by the three points of SMAx1, SMin1 and SMAx2 is CYC1; the circumscribed circle of the triangle formed by the three points of SMAx1, SMin1 and SMin2 is CYC2;
the source stress region and the stressed region in CYC1 and CYC2 are distinguished, and specifically are:
if the average gray value of the pixel points in CYC1 is smaller than the average gray value of the pixel points in CYC2, the direction from the circle center of CYC1 to the circle center of CYC2 is recorded as stress direction, CYC1 is used as a source stress area, and CYC2 is used as a stressed area; otherwise, the direction from the circle center of CYC2 to the circle center of CYC1 is recorded as stress direction, CYC1 is a stressed area, and CYC2 is a source stress area;
specifically, in S500, the method for extracting the visualization area in the sub-area according to the source stress area and the stressed area includes:
the outer common tangent lines of CYC1 and CYC2 are L1 and L2 respectively, and the region between the CYC1, CYC2 and the outer common tangent lines L1 and L2 is taken as the region Area1 to be displayed; the Area1 to be visualized is subjected to the visualization treatment as a visualization Area, and the visualization treatment specifically comprises the following steps:
taking a connecting line of CYC1 and CYC2 as LC, and the length of the LC is LCD;
the source stress Area in the Area to be displayed Area1 is CYCGet, the stress Area in the Area to be displayed Area1 is CYCREC, CYCREC (j 1) is the j1 th pixel point in the CYCREC, and j1 is the serial number of the pixel point in the CYCREC; all CYCREC (j 1) are subjected to the following visualization treatment within the value range of j 1: taking the point of the CYCREC (j 1) along the reverse direction of stress pointing and with the distance of the LCD position as PJ, taking the average gray value of all pixel points with the gray value larger than PJ as GV in the CYCGet, and replacing the gray value of the CYCREC (j 1) with the value of GV;
filling the gray values of all the pixel points except for CYCGet and CYCREC in the region Area1 to be displayed with the gray values of all the pixel points in CYCREC;
marking the Area1 to be visualized as a visualization Area;
specifically, in S600, the method for marking the corresponding position of each of the visualized areas on the biodegradable film where stress whitening exists includes: if the average gray value of the pixel points in the display area is larger than the average gray value of the pixel points in the gray image, judging that stress whitening exists in the display area, and marking the corresponding positions of the display areas with the stress whitening on the biodegradable film.
2. The method for inspecting the position of degradation defect of a biodegradable film according to claim 1, wherein in S100, the method for acquiring an image of a biodegradable film as an image to be inspected comprises: the lower surface of the biodegradable mulching film is irradiated by an LED lamp or a UV lamp, and the upper surface of the biodegradable mulching film is scanned by a CCD industrial camera to obtain an image of the biodegradable mulching film as an image to be detected.
CN202310822116.2A 2023-07-05 2023-07-05 Method for inspecting degradation defect position of biodegradable film Active CN116973367B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310822116.2A CN116973367B (en) 2023-07-05 2023-07-05 Method for inspecting degradation defect position of biodegradable film

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310822116.2A CN116973367B (en) 2023-07-05 2023-07-05 Method for inspecting degradation defect position of biodegradable film

Publications (2)

Publication Number Publication Date
CN116973367A CN116973367A (en) 2023-10-31
CN116973367B true CN116973367B (en) 2024-01-30

Family

ID=88484192

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310822116.2A Active CN116973367B (en) 2023-07-05 2023-07-05 Method for inspecting degradation defect position of biodegradable film

Country Status (1)

Country Link
CN (1) CN116973367B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5383776A (en) * 1992-12-31 1995-01-24 Hoechst Celanese Corporation Apparatus for analyzing polymer defects
JP2000065751A (en) * 1998-08-25 2000-03-03 Nkk Corp Surface inspection apparatus
JP2009264915A (en) * 2008-04-24 2009-11-12 Panasonic Electric Works Co Ltd Visual inspection method and device of transparent film
CN110286126A (en) * 2019-06-17 2019-09-27 浙江大学 A kind of wafer surface defects subregion area detecting method of view-based access control model image
KR20200058912A (en) * 2018-11-20 2020-05-28 한국과학기술연구원 Method for quantitative measurement of defects within block-copolymer thin-flim having lamellar pattern
CN114494210A (en) * 2022-01-28 2022-05-13 江苏豪尚新材料科技有限公司 Plastic film production defect detection method and system based on image processing
CN115684176A (en) * 2022-10-24 2023-02-03 浙江荣图智能科技有限公司 Online visual inspection system for film surface defects

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5383776A (en) * 1992-12-31 1995-01-24 Hoechst Celanese Corporation Apparatus for analyzing polymer defects
JP2000065751A (en) * 1998-08-25 2000-03-03 Nkk Corp Surface inspection apparatus
JP2009264915A (en) * 2008-04-24 2009-11-12 Panasonic Electric Works Co Ltd Visual inspection method and device of transparent film
KR20200058912A (en) * 2018-11-20 2020-05-28 한국과학기술연구원 Method for quantitative measurement of defects within block-copolymer thin-flim having lamellar pattern
CN110286126A (en) * 2019-06-17 2019-09-27 浙江大学 A kind of wafer surface defects subregion area detecting method of view-based access control model image
CN114494210A (en) * 2022-01-28 2022-05-13 江苏豪尚新材料科技有限公司 Plastic film production defect detection method and system based on image processing
CN115684176A (en) * 2022-10-24 2023-02-03 浙江荣图智能科技有限公司 Online visual inspection system for film surface defects

Also Published As

Publication number Publication date
CN116973367A (en) 2023-10-31

Similar Documents

Publication Publication Date Title
Chen et al. Effect of acid hydrolysis on the multi-scale structure change of starch with different amylose content
Barrera et al. Evaluation of the mechanical damage on wheat starch granules by SEM, ESEM, AFM and texture image analysis
Lee et al. Automatic detection of region-mura defect in TFT-LCD
CN113989228A (en) Method for detecting defect area of color texture fabric based on self-attention
Dostál et al. Influence of the repeated extrusion on the degradation of polyethylene. Structural changes in low density polyethylene
CN116973367B (en) Method for inspecting degradation defect position of biodegradable film
Di Giuseppe et al. Reliability evaluation of automated analysis, 2D scanner, and micro-tomography methods for measuring fiber dimensions in polymer-lignocellulosic fiber composites
CN109035226B (en) Mura defect detection method based on LSTM model
CN111861996A (en) Printed fabric defect detection method
CN110189290A (en) Metal surface fine defects detection method and device based on deep learning
CN108318491A (en) A kind of fabric defect detection method based on frequency spectrum curvature analysis
EP3156783A2 (en) A method for classifying a defect in a component intended to have a monocrystalline structure
JP4516253B2 (en) Defect classification device
CN115861310B (en) Method for detecting textile defects on surface of bed sheet
Rebelo et al. Increased degradation of PLA/PBAT blends with organic acids and derivatives in outdoor weathering and marine environment
CN116985444B (en) Traction method for improving transmittance in degradation process of biodegradable film
Koga et al. Accelerated aging-induced variation of polypropylene (PP) structure studied by two-dimensional (2D) small-angle X-ray scattering (SAXS) correlation spectroscopy
CN116990993B (en) LCD display panel quality detection method
CN115256900B (en) Plastic protection film production parameter control method based on image processing
DE102010032241A1 (en) Method for detecting surface defects e.g. cracks at plastic surface of corrugated pipe, involves testing differential image between two partial region images to determine whether coherent regions are provided with grey values
CN117974644B (en) Visual detection method for quality of capsule medicine
CN115049670A (en) Tooth profile defect detection method based on gear
CN111986199A (en) Unsupervised deep learning-based wood floor surface flaw detection method
Moradi et al. A new approach for detecting and grading blistering defect of coatings using a machine vision system
TWI607212B (en) Image generation device, defect inspection device, and defect inspection method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant