Method for detecting and analyzing light transmission of polyvinyl alcohol film

Abstract

The invention discloses a method for detecting and analyzing the light transmission of a polyvinyl alcohol film, and relates to the technical field of film detection. The method comprises the following steps: setting a light transmission detection standard based on a standard polyvinyl alcohol film; carrying out primary detection on the light transmission of the sample film by adopting an image processing algorithm; carrying out secondary detection on the light transmission of the sample film by adopting a UV-Vis spectrum method; carrying out third detection on the light transmission of the sample film by adopting a material characteristic detection method; and based on a light transmittance detection standard, respectively carrying out light transmittance analysis on the three detection results to obtain an influence factor of the light transmittance of the polyvinyl alcohol film, and regulating and controlling the preparation process of the polyvinyl alcohol film according to the influence factor. Through the triple detection, a plurality of influence factors influencing the light transmission of the polyvinyl alcohol film are obtained, and the accuracy and comprehensiveness of light transmission detection are guaranteed; and the production quality, the production efficiency and the product percent of pass of the thin film are improved by controlling and adjusting a plurality of links in the preparation process.

Description

Technical Field

[0001] The invention belongs to the technical field of film detection, and in particular relates to a method for detecting and analyzing the light transmittance of a polyvinyl alcohol film. Background Art

[0002] Polyvinyl alcohol (PVA) film is a commonly used polymer material with excellent physical and chemical properties. It is widely used in packaging, coatings, optoelectronic devices, drug release systems and other fields. Its main characteristics include transparency, mechanical strength, water solubility, good chemical stability and biocompatibility. Since polyvinyl alcohol film has requirements for transparency in specific applications, comprehensive testing and comprehensive evaluation of the light transmittance of polyvinyl alcohol film has become an urgent problem to be solved. Summary of the invention

[0003] The object of the present invention is to provide a method for detecting and analyzing the light transmittance of a polyvinyl alcohol film, which can be achieved by the following technical solutions: The present application provides a method for detecting and analyzing the light transmittance of a polyvinyl alcohol film, comprising the following steps: S1, light transmittance test standard is set based on standard polyvinyl alcohol film; S2, performing a first test on the light transmittance of the sample film and obtaining a first test result; S3, using UV-Vis spectroscopy to perform a second test on the light transmittance of the sample film and obtain a second test result, including the following: Equipment preparation: calibrate the spectrometer and clean the optical path; Wavelength setting: set the wavelength range of the spectrometer; Sample detection: starting the spectrometer to detect the sample film and record the transmittance data; Data processing: Analyze the relationship between transmittance data and wavelength and generate a transmittance curve showing the change of transmittance with wavelength; Data analysis: The transmittance T is calculated based on the transmittance curve, and the formula is: ×100%; in, Indicates the intensity of light transmitted through the sample film; Indicates the incident light intensity; The absorptivity A is also calculated based on the transmittance T, and the formula is: A=1-TR; R represents the reflectivity; S4, performing a third test on the light transmittance of the sample film using a material property test method and obtaining a third test result; S5, based on the light transmittance detection standard, respectively performing light transmittance analysis on the first detection result, the second detection result and the third detection result to obtain an influencing factor of the light transmittance of the polyvinyl alcohol film; S6, regulating the preparation process of the polyvinyl alcohol film based on the influencing factors.

[0004] Preferably, setting the light transmittance detection standard includes: Obtain standard polyvinyl alcohol film; Conduct optical testing on standard polyvinyl alcohol films to obtain standard film parameters; Establishing the light transmittance detection standard based on the standard film parameters; Wherein, the light transmittance detection standard includes standard reflectivity, standard transmittance and standard absorbance. Preferably, the first level of testing of the light transmittance of the sample film includes the following: Performing imaging scanning on the sample film to obtain a sample film image; Using an image processing algorithm to perform image analysis on the sample film image to obtain the sample defect area; Performing microstructural testing on the defective area of ​​the sample to obtain microstructural data; performing data analysis on the microstructure data to determine sample defect types; Marking and locating the location of the sample defect type in the sample defect area; The sample defect area, sample defect type and positioning mark are output as the first detection result.

[0005] Preferably, the image processing algorithm is used to perform image analysis on the sample film image, including the following contents: Preprocessing the sample film image, including: contrast adjustment and pixel adjustment; Applying an image processing algorithm to identify the sample film image to obtain the surface abnormal area in the image; comparing the light transmittance detection standard with the sample film image to obtain a pixel set that deviates from a normal range, wherein the pixel set represents a potential defect area; Comprehensively analyzing the surface abnormal area and potential defect area to obtain a comprehensive sample defect area; In the sample film image, setting the area outside the sample defect area as a sample non-defect area; The sample defect area is processed by using image segmentation technology, and the color, texture and shape characteristics in the sample film image are analyzed to separate the sample defect area from the sample non-defect area. Preferably, performing data analysis on the microstructure data to determine the sample defect type comprises: Classifying each identified sample defect area; Analyzing the microstructure data to obtain the size, shape, boundary characteristics of sample defects and their distribution pattern in the sample film image; Classify sample defects into different types; The sample defect types include scratches, bubbles, impurities, shadows, cracks, holes and depressions.

[0006] Preferably, a third level of testing is performed on the light transmittance of the sample film, including thickness testing, water content testing and environmental testing.

[0007] Preferably, the thickness detection includes the following contents: irradiating the sample film with a light source; Acquire an incident image of the incident light emitted by the light source by means of a camera device; Acquiring an outgoing image of the outgoing light passing through the sample film by means of a camera device; Processing the incident image and the outgoing image to obtain an incident grayscale value of each pixel in the incident image and an outgoing grayscale value of each pixel in the outgoing image; The thickness value of the sample film is calculated according to the incident grayscale value, the output grayscale value, a preset extinction coefficient and a preset correction function. Preferably, the thickness value The calculation formula is expressed as: [-log( )+C( , )]; Where a is the preset extinction coefficient; is the incident grayscale value of the pixel in the incident image; is the output grayscale value of the pixel in the output image; C is the preset correction function.

[0008] Preferably, the water content detection and the environment detection include the following contents: The water content of the sample film is detected by the Karl Fischer method or the drying method to obtain the film water content value; Detecting the environment where the sample film is located to obtain an environmental humidity value; Obtaining the water solubility parameter of the sample film and calculating the film water absorption value of the sample film in combination with the ambient humidity value; The comprehensive water content of the sample film is calculated based on the film water content value and the film water absorption value. Preferably, the factors affecting the light transmittance of the polyvinyl alcohol film include the light transmittance of the film, the absorptivity of the film, the thickness of the film and the comprehensive water content of the film.

[0009] The beneficial effects of the present invention are: (1) The present invention first sets a light transmittance detection standard based on a standard polyvinyl alcohol film; then uses an image processing algorithm to perform a first-level detection on the light transmittance of the sample film and obtains a first detection result; then uses UV-Vis spectroscopy to perform a second-level detection on the light transmittance of the sample film and obtains a second detection result; then uses a material property detection method to perform a third-level detection on the light transmittance of the sample film and obtains a third detection result; finally, based on the light transmittance detection standard, the first detection result, the second detection result, and the third detection result are respectively analyzed for light transmittance, so as to obtain the influencing factors of the light transmittance of the polyvinyl alcohol film; and in order to improve the quality of the finished product of the polyvinyl alcohol film, the preparation process of the polyvinyl alcohol film is finally regulated based on the above-mentioned influencing factors, and the production quality and production efficiency of the final polyvinyl alcohol film, as well as the product qualification rate, are improved by controlling and adjusting multiple links in the preparation process.

[0010] (2) The present invention obtains multiple influencing factors that affect the light transmittance of the polyvinyl alcohol film through the above-mentioned triple detection, and controls the light transmittance of the film by testing and controlling the above-mentioned influencing factors. The accuracy and comprehensiveness of the light transmittance detection are ensured through the triple detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For better understanding and implementation, the technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0012] Figure 1 A flowchart of a method for detecting and analyzing the light transmittance of a polyvinyl alcohol film provided in an embodiment of the present application; Figure 2 A flowchart of the steps for performing the first level of detection provided in an embodiment of the present application; Figure 3 A flowchart of the steps for performing image analysis provided in an embodiment of the present application; Figure 4 A flowchart of the steps of thickness detection in the third level of detection provided in an embodiment of the present application. DETAILED DESCRIPTION

[0013] In order to further explain the technical means and effects taken by the present invention to achieve the predetermined invention purpose, exemplary embodiments will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are only examples of methods and systems consistent with some aspects of the present application as detailed in the attached claims.

[0014] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to any or all possible combinations of one or more associated listed items.

[0015] The specific implementation methods, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0016] See also Figure 1 The present invention provides a method for detecting and analyzing the light transmittance of a polyvinyl alcohol film, comprising the following steps: S1, light transmittance test standard is set based on standard polyvinyl alcohol film; S2, performing a first test on the light transmittance of the sample film and obtaining a first test result; S3, performing a second test on the light transmittance of the sample film by UV-Vis spectroscopy and obtaining a second test result; S4, performing a third test on the light transmittance of the sample film using a material property test method and obtaining a third test result; S5, based on the light transmittance detection standard, respectively performing light transmittance analysis on the first detection result, the second detection result and the third detection result to obtain an influencing factor of the light transmittance of the polyvinyl alcohol film; S6, regulating the preparation process of the polyvinyl alcohol film based on the influencing factors.

[0017] Specifically, since the light transmittance of polyvinyl alcohol film will be affected by many factors, in order to ensure the accuracy and comprehensiveness of its light transmittance detection, the present application provides the following light transmittance detection method: first, a light transmittance detection standard is set based on a standard polyvinyl alcohol film; then, an image processing algorithm is used to perform a first detection on the light transmittance of the sample film and a first detection result is obtained; then, UV-Vis spectroscopy is used to perform a second detection on the light transmittance of the sample film and a second detection result is obtained; then, a material property detection method is used to perform a third detection on the light transmittance of the sample film and a third detection result is obtained; finally, based on the light transmittance detection standard, the first detection result, the second detection result, and the third detection result are respectively analyzed for light transmittance, so as to obtain the influencing factors of the light transmittance of the polyvinyl alcohol film; and in order to improve the quality of the finished product of the polyvinyl alcohol film, the preparation process of the polyvinyl alcohol film is finally regulated based on the above-mentioned influencing factors, and the production quality and production efficiency of the final polyvinyl alcohol film, as well as the product qualification rate, are improved by controlling and adjusting multiple links in the preparation process.

[0018] In an embodiment provided in the present application, setting the light transmittance detection standard in step S1 includes: Obtain standard polyvinyl alcohol film; Conduct optical testing on standard polyvinyl alcohol films to obtain standard film parameters; Establishing the light transmittance detection standard based on the standard film parameters; Wherein, the light transmittance detection standard includes standard reflectivity, standard transmittance and standard absorbance.

[0019] Specifically, in order to establish the light transmittance detection standard, this embodiment first obtains a polyvinyl alcohol film that meets the standard and has good production quality as a standard polyvinyl alcohol film; secondly, the standard polyvinyl alcohol film is optically tested to obtain standard film parameters, including but not limited to film thickness, film water content, film water solubility, light transmittance, reflectivity, absorptivity, optical band gap, refractive index, film uniformity, surface roughness and light scattering; finally, based on the above standard film parameters, a light transmittance detection standard including standard reflectivity, standard transmittance and standard absorptivity is established. It can be understood that the above light transmittance detection standard can reflect the various characteristic parameters of the polyvinyl alcohol film under the standard state, so as to serve as a comparison standard for subsequent sample films.

[0020] like Figure 2 As shown, in one embodiment provided in the present application, in step S2, the light transmittance of the sample film is first tested, including the following contents: Performing imaging scanning on the sample film to obtain a sample film image; Using an image processing algorithm to perform image analysis on the sample film image to obtain the sample defect area; Performing microstructural testing on the defective area of ​​the sample to obtain microstructural data; performing data analysis on the microstructure data to determine sample defect types; Marking and locating the location of the sample defect type in the sample defect area; The sample defect area, sample defect type and positioning mark are output as the first detection result.

[0021] like Figure 3 As shown, in one embodiment provided in the present application, an image processing algorithm is used to perform image analysis on the sample film image, including the following contents: Preprocessing the sample film image, including: contrast adjustment and pixel adjustment; Applying an image processing algorithm to identify the sample film image to obtain the surface abnormal area in the image; comparing the light transmittance detection standard with the sample film image to obtain a pixel set that deviates from a normal range, wherein the pixel set represents a potential defect area; Comprehensively analyzing the surface abnormal area and potential defect area to obtain a comprehensive sample defect area; In the sample film image, setting the area outside the sample defect area as a sample non-defect area; The sample defect area is processed by using image segmentation technology, and the color, texture and shape characteristics in the sample film image are analyzed to separate the sample defect area from the sample non-defect area.

[0022] In one embodiment provided in the present application, data analysis is performed on the microstructure data to determine the sample defect type, including: Classifying each identified sample defect region, and classifying the sample defects into different types according to the size, shape, boundary characteristics of the sample defects and their distribution patterns in the sample film image; The sample defect types include scratches, bubbles, impurities, shadows, cracks, holes and depressions.

[0023] In one embodiment provided in the present application, a second detection of the light transmittance of the sample film is performed in step S3, including the following contents: Equipment preparation: calibrate the spectrometer and clean the optical path; Wavelength setting: set the wavelength range of the spectrometer; Sample detection: starting the spectrometer to detect the sample film and record the transmittance data; Data processing: Analyze the relationship between transmittance data and wavelength and generate a transmittance curve showing the change of transmittance with wavelength; Data analysis: The transmittance T is calculated based on the transmittance curve, and the formula is: ×100%; in, It indicates the intensity of light transmitted through the sample; Indicates the incident light intensity; The absorptivity A is also calculated based on the transmittance T, and the formula is: A=1-TR; R represents the reflectivity.

[0024] Specifically, this embodiment uses UV-Vis spectroscopy to detect the light transmittance of the sample film. In the equipment preparation stage, a standard light source and a standard sample (such as air or transparent glass) are used to calibrate the spectrometer to ensure its accuracy; the optical path is also cleaned to ensure that the optical path and sample pool of the spectrometer are free of dust and pollutants to avoid affecting the measurement results; then a suitable wavelength range (usually 200-800 nm) is selected; then the sample film is placed in the sample pool to ensure that the light beam can pass through the film; then the spectrometer is started and the transmittance (transmittance) data is recorded, and the absorption spectrum can be obtained at different wavelengths; then a relationship diagram between transmittance and wavelength is obtained to show a curve of transmittance changing with wavelength; then the transmittance is calculated by the above formula, and finally, according to the transmittance curve, the transmittance of the film in a specific wavelength range is evaluated, and it is compared with the standard to determine the optical properties of the film. Through the above steps, the UV-Vis spectroscopy can be effectively used to detect the light transmittance of the sample film, thereby obtaining its optical characteristic data.

[0025] In an embodiment provided in the present application, in step S4, a third level of detection is performed on the light transmittance of the sample film, including thickness detection, water content detection and environment detection.

[0026] Specifically, this embodiment performs tests on three aspects, namely thickness, water content and environment, in the third level of testing to ensure the accuracy and comprehensiveness of the test.

[0027] like Figure 4 As shown, in one embodiment provided in the present application, the light transmittance of the sample film is tested for thickness, including the following contents: irradiating the sample film with a light source; Acquire an incident image of the incident light emitted by the light source by means of a camera device; Acquiring an outgoing image of the outgoing light passing through the sample film by means of a camera device; Processing the incident image and the outgoing image to obtain an incident grayscale value of each pixel in the incident image and an outgoing grayscale value of each pixel in the outgoing image; The thickness value of the sample film is calculated according to the incident grayscale value, the output grayscale value, a preset extinction coefficient and a preset correction function.

[0028] In one embodiment provided in the present application, the thickness value The calculation formula is expressed as: [-log( )+C( , )]; Where a is the preset extinction coefficient; is the incident grayscale value of the pixel in the incident image; is the output grayscale value of the pixel in the output image; C is the preset correction function.

[0029] In one embodiment provided in the present application, the water content detection and environmental detection of the light transmittance of the sample film are performed, including the following contents: The water content of the sample film is detected by the Karl Fischer method or the drying method to obtain the film water content value; Detecting the environment where the sample film is located to obtain an environmental humidity value; Obtaining the water solubility parameter of the sample film and calculating the film water absorption value of the sample film in combination with the ambient humidity value; The comprehensive water content of the sample film is calculated based on the film water content value and the film water absorption value.

[0030] Specifically, the polyvinyl alcohol film itself is water-soluble and will absorb water, thereby affecting its light transmittance. Therefore, it is necessary to detect its own water content and the humidity of the surrounding environment.

[0031] In an embodiment provided in the present application, film transmittance, film absorptivity, film thickness and film comprehensive water content are used as influencing factors of the light transmittance of the polyvinyl alcohol film.

[0032] In summary, the present application obtains multiple influencing factors that affect the light transmittance of the polyvinyl alcohol film through the above-mentioned triple detection, and regulates the light transmittance of the film by testing and regulating the above-mentioned influencing factors, and ensures the accuracy and comprehensiveness of the light transmittance detection through triple detection.

[0033] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for detecting and analyzing the light transmittance of a polyvinyl alcohol film, characterized in that: The steps include: S1, light transmittance test standard is set based on standard polyvinyl alcohol film; S2, performing a first test on the light transmittance of the sample film and obtaining a first test result; S3, using UV-Vis spectroscopy to perform a second test on the light transmittance of the sample film and obtain a second test result, including the following: Equipment preparation: calibrate the spectrometer and clean the optical path; Wavelength setting: set the wavelength range of the spectrometer; Sample detection: starting the spectrometer to detect the sample film and record the transmittance data; Data processing: Analyze the relationship between transmittance data and wavelength and generate a transmittance curve showing the change of transmittance with wavelength; Data analysis: The transmittance T is calculated based on the transmittance curve, and the formula is: ×100％； in, Indicates the intensity of light transmitted through the sample film; Indicates the incident light intensity; The absorptivity A is also calculated based on the transmittance T, and the formula is: A=1-TR; R represents the reflectivity; S4, performing a third test on the light transmittance of the sample film using a material property test method and obtaining a third test result; S5, based on the light transmittance detection standard, respectively performing light transmittance analysis on the first detection result, the second detection result and the third detection result to obtain an influencing factor of the light transmittance of the polyvinyl alcohol film; S6, regulating the preparation process of the polyvinyl alcohol film based on the influencing factors.

2. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 1, characterized in that: Setting the light transmittance detection standard includes: Obtain standard polyvinyl alcohol film; Conduct optical testing on standard polyvinyl alcohol films to obtain standard film parameters; Establishing the light transmittance detection standard based on the standard film parameters; Wherein, the light transmittance detection standard includes standard reflectivity, standard transmittance and standard absorbance.

3. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 1, characterized in that: The first test of the light transmittance of the sample film includes the following: Performing imaging scanning on the sample film to obtain a sample film image; Using an image processing algorithm to perform image analysis on the sample film image to obtain the sample defect area; Performing microstructural testing on the defective area of ​​the sample to obtain microstructural data; performing data analysis on the microstructure data to determine sample defect types; Marking and locating the location of the sample defect type in the sample defect area; The sample defect area, sample defect type and positioning mark are output as the first detection result.

4. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 3, characterized in that: The sample film image is analyzed using an image processing algorithm, including the following contents: Preprocessing the sample film image, including: contrast adjustment and pixel adjustment; Applying an image processing algorithm to identify the sample film image to obtain the surface abnormal area in the image; comparing the light transmittance detection standard with the sample film image to obtain a pixel set that deviates from a normal range, wherein the pixel set represents a potential defect area; Comprehensively analyzing the surface abnormal area and potential defect area to obtain a comprehensive sample defect area; In the sample film image, setting the area outside the sample defect area as a sample non-defect area; The sample defect area is processed by using image segmentation technology, and the color, texture and shape characteristics in the sample film image are analyzed to separate the sample defect area from the sample non-defect area.

5. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 3, characterized in that: The microstructure data is analyzed to determine the sample defect type, including: Classifying each identified sample defect area; Analyzing the microstructure data to obtain the size, shape, boundary characteristics of sample defects and their distribution pattern in the sample film image; Classify sample defects into different types; The sample defect types include scratches, bubbles, impurities, shadows, cracks, holes and depressions.

6. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 1, characterized in that: The light transmittance of the sample film is tested for the third level, including thickness testing, moisture content testing and environmental testing.

7. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 6, characterized in that: The thickness detection includes the following contents: irradiating the sample film with a light source; Acquire an incident image of the incident light emitted by the light source by means of a camera device; Acquiring an outgoing image of the outgoing light passing through the sample film by means of a camera device; Processing the incident image and the outgoing image to obtain an incident grayscale value of each pixel in the incident image and an outgoing grayscale value of each pixel in the outgoing image; The thickness value of the sample film is calculated according to the incident grayscale value, the output grayscale value, a preset extinction coefficient and a preset correction function.

8. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 7, characterized in that: Thickness value The calculation formula is expressed as: [-log( )+C( , )]; Where a is the preset extinction coefficient; is the incident grayscale value of the pixel in the incident image; is the output grayscale value of the pixel in the output image; C is the preset correction function.

9. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 8, characterized in that: The water content detection and the environmental detection include the following contents: The water content of the sample film is detected by the Karl Fischer method or the drying method to obtain the film water content value; Detecting the environment where the sample film is located to obtain an environmental humidity value; Obtaining the water solubility parameter of the sample film and calculating the film water absorption value of the sample film in combination with the ambient humidity value; The comprehensive water content of the sample film is calculated based on the film water content value and the film water absorption value.

10. The method for detecting and analyzing the light transmittance of a polyvinyl alcohol film according to claim 1, characterized in that: The factors affecting the light transmittance of polyvinyl alcohol film include film transmittance, film absorptivity, film thickness and film comprehensive water content.

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