Wet film thickness difference measurement and evenness assessment method of metal sheet printing coating

Abstract

The invention discloses a wet film thickness difference measurement and evenness assessment method of metal sheet printing coating. The method includes the following steps: (1) a metal sheet to be coated is placed on a thickness measuring platform which can be move in the X direction and a scanning thickness measuring mechanism which is provided with a laser double measuring heads can move along the Y direction so that the collection of multiple cloud data in the XOY plane of the metal sheet can be realized; (2) the coated metal sheet is placed on the same position of the thickness measuring platform and scanned and measured along the original route; (3) data processing is conducted on the data before and after the same metal sheet is coated according to the principle of difference measurement so that the coating thickness of the measured point can be obtained; (4) fitting is conducted on the measured thickness data according to the principle of least squares and the cubic spline interpolation algorithm so that a three-dimensional graphics of the surface coating thickness of the metal sheet can be obtained and the evenness of the surface coating thickness of the whole metal sheet can be assessed. The wet film thickness different measurement and evenness assessment method of the metal sheet printing coating can effectively assess the evenness of the printing coating thickness of the metal sheet and provides an evidence of the coating mechanism of the metal sheet.

Description

technical field [0001] The invention relates to the technical field of wet film thickness measurement of metal sheet coatings, in particular to a wet film thickness differential measurement and uniformity evaluation method of metal sheet printing coatings. Background technique [0002] In the metal sheet printing process, coating is an essential step, and the coating thickness is one of the important factors affecting the coating quality. Too thick, too thin or uneven thickness will affect the adhesion, impact resistance and coating quality. The surface hardness of the layer is affected, so the detection of the coating thickness is particularly important. [0003] The detection method often used in the metal sheet printing industry is the weighing estimation method after drying, that is, after the coating is completed, the metal sheet is sent to the drying room, and after the coating is completely dry, the sample is cut and weighed. The average thickness of the coating is e...

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Problems solved by technology

[0003] The detection method often used in the metal sheet printing industry is the weighing estimation method after drying, that is, after the coating is completed, the metal sheet is sent to the drying room, and after the coating is completely dry, the sample is cut and weighed. The average thickness of the coating is estimated by the quality of the coating on the surface. This method is not accurate in measurement and has hysteresis, and it is difficult to remove the coating after drying. If the thickness does not meet the standard, it is easy to cause waste.

In recent years, with the rapid development of film thickness measurement technology, some other measurement methods have emerged, which can be mainly divided into two types: contact type and non-contact type. The contact type measurement methods are mainly mechanical measurement and ultrasonic measurement. The contact measurement method cannot meet the thickness measurement of the wet film of the metal sheet printing coating; the non-contact measurement includes ray type, eddy current type, capacitive type, laser type and other measurement methods, among which the laser thickness measurement method is due to its high measurement accuracy and stability. The advantages of good performance and no pollution are widely used, but at present, the method of using laser dual probes to achieve high-precision measurement of coatings is mostly single-point data acquisition, that is, only the thickness measurement is completed. For example, the patent "A Lithium Battery Thin Film Micro Displacement Thickness Measurement Method" (CN 103148790 A) discloses a measurement principle using dual laser sensors for thickness measurement and a subsequent related data processing method, which mentions denoising, filtering and other processing of measurement data, and does not involve uniformity evaluation and other technical methods; another example is the patent "Laser Measuring Device for Plate Thickness" (CN 102706286 A) which discloses a device for continuous measurement of plate thickness using upper and lower laser sensors, and does not mention the estimation of the entire plate thickness based on actual measurement results. The problem of the thickness of the surface of the plate

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