Preparation method of high-weather-resistance fine steel anticorrosion steel-plastic plate

Abstract

The present application relates to the technical field of steel-plastic plate preparation, and particularly relates to a preparation method of high-weather-resistance fine-steel anticorrosive steel-plastic plate, which comprises the following steps: preparing a steel-plastic plate base material by combining a first weather-resistance modified hot melt layer of a composite anticorrosive function back film and a first galvanized layer of a galvanized sheet; determining whether the structural stability of the steel-plastic plate base material is qualified based on a uniform morphology characterization parameter, and adjusting a temperature difference according to a difference; preparing a composite steel-plastic plate by combining a chemical conversion layer of a composite anticorrosive function front film and a second galvanized layer of the steel-plastic plate base material with qualified structural stability; determining whether the layer bonding reliability is qualified based on an interface wetting index, and adjusting a pressure or a walking speed according to a ratio; determining whether the stress balance of the composite steel-plastic plate is up to standard based on an interface stress matching coefficient, and adjusting a winding pressure according to a relative difference; and obtaining the high-weather-resistance fine-steel anticorrosive steel-plastic plate under the condition that the stress balance is up to standard. The present application improves the stability of the preparation of the high-weather-resistance fine-steel anticorrosive steel-plastic plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel-plastic plate preparation, and particularly relates to a preparation method of high-weather-resistance fine-steel anti-corrosion steel-plastic plate. BACKGROUND

[0002] As a new building material with both metal strength and polymer corrosion resistance, steel-plastic composite plate is widely used in the fields of construction, transportation, etc., especially in high-weather-resistance and strong-corrosion environments. Traditional steel-plastic plate preparation processes usually adopt hot pressing, chemical conversion treatment and lamination technology. However, the uniformity of the interface infiltration between the hot melt layer and the galvanized layer is difficult to monitor and control in real time, and defects such as local non-combination and bubbles are prone to occur, which leads to poor stability of the base material structure, the bonding strength between the chemical conversion layer and the base material depends on offline sampling detection, lacks online quality feedback, and the lamination process parameters are fixed and cannot be self-adaptively adjusted, which easily causes unreliable interface bonding, and the difference in the thermal expansion coefficients of the materials in the composite process causes the accumulation of internal stress, and the lack of stress matching guidance in the winding tension control leads to product warping and delamination, affecting long-term durability.

[0003] Chinese Patent Application Publication No. CN118700652A discloses a kind of multilayer composite fine steel anti-corrosion steel-plastic plate and its preparation method, which comprises: the high-molecular hot melt adhesive layer in the prepared weather-resistant anti-corrosion PET back film is laminated with the galvanized layer of the galvanized sheet by heating and laminating through the upper roller and then winding, then the galvanized layer laminated with the back film is laminated with the high-molecular hot melt adhesive layer of the weather-resistant anti-corrosion PET front film by heating and laminating through the upper roller and then winding to prepare a kind of multilayer composite fine steel anti-corrosion steel-plastic plate;Then, the average roughness and the maximum peak-to-valley height are obtained by detecting the roughness parameters of the surface of the multilayer composite fine steel anti-corrosion steel-plastic plate;Finally, the reasons for the surface quality of the multilayer composite fine steel anti-corrosion steel-plastic plate not meeting the standard are determined according to the average roughness, and the temperature of the upper roller or the vertical distance between the upper roller and the lower roller is adjusted according to the reasons.

[0004] However, the existing technology has the following problems: relying on the surface roughness of the final product to deduce the quality problem, the technical means is single, and the surface roughness only reflects the physical appearance, ignoring the microstructure, thereby leading to the problem of low preparation stability of the high-weather-resistance fine-steel anti-corrosion steel-plastic plate. SUMMARY

[0005] Therefore, the present application provides a preparation method of high-weather-resistance fine-steel anti-corrosion steel-plastic plate to overcome the problem of relying on the surface roughness of the final product to deduce the quality problem in the prior art, the technical means is single, and the surface roughness only reflects the physical appearance, ignoring the microstructure, thereby leading to the problem of low preparation stability of the high-weather-resistance fine-steel anti-corrosion steel-plastic plate.

[0006] To achieve the above-mentioned purpose, the present application provides a preparation method of high-weather-resistance fine-steel anti-corrosion steel-plastic plate, comprising:

[0007] The first weather-resistant modified hot melt layer of the composite anticorrosion functional back film is prepared into a steel-plastic plate substrate with the first galvanized layer of the galvanized sheet;

[0008] A surface and edge cross-sectional image of the steel-plastic plate substrate is obtained, and a topography uniformity characterization parameter is determined based on the surface and edge cross-sectional image to determine whether the structural stability of the steel-plastic plate substrate is qualified, and a temperature difference between the upper roller and the lower roller is adjusted according to a difference between the topography uniformity characterization parameter and a preset topography uniformity characterization parameter;

[0009] The chemical conversion layer of the composite anticorrosion functional front film is prepared into a composite steel-plastic plate with the second galvanized layer of the steel-plastic plate substrate with qualified structural stability, wherein

[0010] The second weather-resistant modified hot melt layer of the composite anticorrosion functional front film is in direct contact with the second galvanized layer, and the chemical layer is located on the outside of the front film;

[0011] Spectrum data of the composite steel-plastic plate is obtained, and an interface wetting index is determined based on the spectrum data to determine whether the layer bonding reliability of the composite anticorrosion functional front film and the steel-plastic plate substrate is qualified, and the pressure or speed of the laminating roller is adjusted according to a ratio of the interface wetting index to a preset interface wetting index;

[0012] Surface profile data of the composite steel-plastic plate with qualified layer bonding reliability is obtained, and an interface stress matching coefficient is determined based on the surface profile data to determine whether the stress balance of the composite steel-plastic plate meets the standard, and the winding pressure of the tension roller is adjusted according to a relative difference between the preset interface stress matching coefficient and the interface stress matching coefficient;

[0013] A high-weather-resistant fine steel anticorrosion steel-plastic plate is obtained under the condition that the stress balance meets the standard.

[0014] Further, the unqualified structural stability of the steel-plastic plate substrate is determined based on a comparison result that the topography uniformity characterization parameter is greater than the preset topography uniformity characterization parameter, wherein

[0015] The topography uniformity characterization parameter is determined according to a surface gray scale uniformity index and a cross-sectional uniformity index.

[0016] Further, the process of adjusting the temperature difference between the upper roller and the lower roller includes:

[0017] A difference between the topography uniformity characterization parameter of the steel-plastic plate substrate under the unqualified structural stability condition and the preset topography uniformity characterization parameter is calculated;

[0018] Based on a comparison result that the difference is less than or equal to a preset difference, the temperature difference between the upper roller and the lower roller is increased by a first preset temperature adjustment coefficient;

[0019] determine, based on a comparison result that the difference is greater than a preset difference, to increase the temperature difference between the upper roller and the lower roller by a second preset temperature adjustment coefficient.

[0020] Further, the adhesion reliability of the composite anticorrosion functional front film and the layer of the steel-plastic plate substrate is determined to be unqualified based on a comparison result that the interfacial wetting index is less than or equal to a preset interfacial wetting index, wherein,

[0021] The interfacial wetting index is determined according to the characteristic wave band proportion and the defect influence coefficient.

[0022] Further, the process of adjusting the pressure of the laminating roller includes:

[0023] Calculate the ratio of the interfacial wetting index under the condition that the adhesion reliability of the composite anticorrosion functional front film and the layer of the steel-plastic plate substrate is unqualified to the preset interfacial wetting index;

[0024] Determine to increase the pressure of the laminating roller based on a comparison result that the ratio is less than or equal to a preset ratio;

[0025] The increased pressure of the laminating roller is determined according to the pressure of the laminating roller and a preset pressure adjustment coefficient.

[0026] Further, the process of adjusting the speed of the laminating roller includes:

[0027] Calculate the ratio of the interfacial wetting index under the condition that the adhesion reliability of the composite anticorrosion functional front film and the layer of the steel-plastic plate substrate is unqualified to the preset interfacial wetting index;

[0028] Determine to decrease the speed of the laminating roller based on a comparison result that the ratio is greater than a preset ratio;

[0029] The decreased speed of the laminating roller is determined according to the speed of the laminating roller and a preset speed adjustment coefficient.

[0030] Further, the stress balance of the composite steel-plastic plate is determined to be unqualified based on a comparison result that the interfacial stress matching coefficient is less than or equal to a preset interfacial stress matching coefficient, wherein,

[0031] The interfacial stress matching coefficient is determined according to the curvature change rate standard deviation and the curvature change rate average value.

[0032] Further, the process of adjusting the winding pressure of the tension roller includes:

[0033] Calculate the relative difference between the preset interfacial stress matching coefficient and the interfacial stress matching coefficient under the condition that the stress balance of the composite steel-plastic plate is unqualified;

[0034] Determine to decrease the winding pressure by a first preset winding pressure optimization coefficient based on a comparison result that the relative difference is less than or equal to a preset relative difference.

[0035] Determine to reduce the winding pressure by the second preset winding pressure optimization coefficient based on the comparison result that the relative difference is greater than the preset relative difference.

[0036] Further, the preparation process of the composite anticorrosion functional back film comprises: compounding the first weather-resistant modified hot melt layer and the first galvanized layer of the galvanized sheet through a double-roller hot compounding machine to form the composite anticorrosion functional back film.

[0037] Further, the preparation process of the composite anticorrosion functional back film comprises: compounding the first weather-resistant modified hot melt layer and the first galvanized layer of the galvanized sheet through a double-roller hot compounding machine to form the composite anticorrosion functional back film.

[0038] Compared with the prior art, the beneficial effects of the present application are that the present application analyzes the structural stability of the steel-plastic plate substrate through the uniformity of the morphology characterization parameter, and adjusts the temperature difference between the upper roller and the lower roller for the unstable steel-plastic plate substrate, then evaluates the bonding reliability of the front film and the substrate according to the interface wetting index, and adjusts the laminating parameters for the unreliable composite steel-plastic plate, finally determines the stress matching property of the composite steel-plastic plate based on the interface stress matching coefficient, and adjusts the winding pressure when the stress matching is not matched to ensure the stress balance, the surface and cross-section image analysis can directly capture the interface wetting defects of the hot melt layer and the galvanized layer, dynamically adjust the temperature difference between the upper and lower rollers, ensure the uniform coating of the molten resin on the metal substrate, and improve the structural stability of the steel-plastic plate substrate, the characteristic wavelength change in the spectral data can quantify the bonding strength of the chemical conversion layer and the steel-plastic plate substrate, and the surface profile data analyzes the stress concentration area, the winding pressure compensation through the tension roller balances the stress difference between the layers of the composite plate, and improves the consistency and reliability of the high-weather-resistant fine steel anticorrosion steel-plastic plate, thereby improving the stability of the preparation of the high-weather-resistant fine steel anticorrosion steel-plastic plate.

[0039] Further, the present application analyzes the uniformity of the morphology of the steel-plastic plate substrate through the surface and cross-section image, increases the temperature difference between the upper and lower rollers to optimize the wetting effect of the hot melt layer when the uniformity is not up to standard, evaluates the structural stability of the substrate according to the weighted integration of the surface gray uniformity reflecting the uniformity of the hot melt layer and the cross-section profile deviation reflecting the interface bonding flatness, the low surface gray standard deviation indicates that the hot melt layer has no local accumulation or cavity, and the small cross-section profile deviation indicates that there is no wave or stratification at the interface between the galvanized layer and the hot melt layer, thereby ensuring the reliability of the initial bonding of the substrate, the temperature difference between the upper and lower rollers affects the melting state and flow performance of the hot melt layer, increasing the temperature difference can improve the spreading ability of the hot melt layer on the surface of the galvanized layer, reduce the interface gap, and realize the compensation of the wetting defects of the hot melt layer, and the uniform morphology can block the penetration path of the corrosion medium, avoid local corrosion caused by interface defects, and improve the overall weather resistance.

[0040] Further, the present application determines whether the adhesion reliability of the composite anticorrosion functional front film and the steel-plastic plate substrate is qualified by extracting the visible light range reflectivity and calculating the interface wetting index. When unqualified, the lamination roller pressure is increased or the lamination roller speed is reduced. The characteristic waveband proportion reflects the wetting degree of the chemical conversion layer and the substrate. When the wetting is good, the characteristic waveband reflectivity integral is high, and the proportion is large. The defect influence coefficient identifies the characteristic peak caused by poor wetting through the second derivative of the spectrum. The fewer the peak numbers, the higher the coefficient. After weighting, the interface wetting index comprehensively considers the effective coverage and defect control of the bonding interface, and quantifies the adhesion reliability of the layer. Increasing the pressure can enhance the fluidity of the resin, promote the close contact of the film and the substrate, reduce the speed, prolong the hot pressing time, ensure the full wetting and curing of the resin, and improve the interfacial bonding strength of the chemical conversion layer and the steel-plastic plate substrate. Good wetting can ensure that the anticorrosion functional film and the substrate form a continuous and dense protective layer, avoid the penetration of corrosive medium due to delamination, and improve the corrosion and weather resistance of the steel-plastic plate.

[0041] Further, the present application determines whether the stress balance of the composite steel-plastic plate is up to standard through the interface stress matching coefficient. If not, the tension roller winding pressure is reduced to optimize the stress balance between the layers. The curvature change rate reflects the deformation coordination of the layers of the composite plate and characterizes the uniformity of the stress distribution between the layers. By reducing the tension difference between the layers, the internal stress caused by the different material shrinkage rates is balanced. The winding pressure of the tension roller affects the stress state of the layers of the composite plate during the winding process. Too high winding pressure will intensify the stretching of the outer layer material, resulting in compression stress of the inner layer material due to limited shrinkage, and reducing the winding pressure can release the interlayer constraint, so that each layer completes stress relaxation in a natural state, avoiding interlayer peeling or surface warping caused by stress concentration. Balanced stress distribution can avoid the expansion of micro-cracks caused by temperature changes or mechanical loads during use, ensuring the long-term close combination of the anticorrosion functional film and the substrate, and improving the weather resistance and corrosion resistance of the steel-plastic plate. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The flowchart of the preparation method of the high-weather-resistant fine steel anticorrosion steel-plastic plate of the embodiment of the present application is shown in the figure.

[0043] Figure 2 The structure schematic diagram of the high-weather-resistant fine steel anticorrosion steel-plastic plate of the embodiment of the present application is shown in the figure.

[0044] Figure 3 The flowchart of determining whether the structural stability of the steel-plastic plate substrate is qualified is shown in the figure.

[0045] Figure 4 The flowchart of determining whether the stress balance of the composite steel-plastic plate is up to standard is shown in the figure.

[0046] In the figure, 1, steel sheet layer; 2, first galvanized layer; 3, first weather-resistant modified hot melt layer; 4, anticorrosion back layer; 5, second galvanized layer; 6, second weather-resistant modified hot melt layer; 7, chemical conversion layer; 8, weather-resistant anticorrosion heat insulation surface layer. DETAILED DESCRIPTION

[0047] In order to make the objects and advantages of the present application clearer, the present application will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0048] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and not to limit the protection scope of the present application.

[0049] It should be pointed out that the data in the present embodiment are obtained by comprehensive analysis and evaluation of historical detection data and corresponding historical detection results in the three months before the present detection by the present application. Those skilled in the art can understand that the determination method of the present application for a single parameter can be to select the value with the highest proportion as the preset standard parameter according to the data distribution, to use weighted summation to obtain the value as the preset standard parameter, to substitute each historical data into a specific formula and to obtain the value by the formula as the preset standard parameter or other selection methods, as long as the present application can clearly define different specific situations in the single determination process by the obtained value.

[0050] Please refer to Figure 1 As shown in the figure, it is a flow chart of the preparation method of the high-weather-resistant fine steel anticorrosive steel-plastic plate according to the present embodiment.

[0051] The preparation method of the high-weather-resistant fine steel anticorrosive steel-plastic plate according to the present embodiment comprises:

[0052] Step S1, the first weather-resistant modified hot melt layer of the composite anticorrosion functional back film is prepared with the first galvanized layer of the galvanized sheet to form a steel-plastic plate base material;

[0053] Step S2, the surface and edge cross-sectional images of the steel-plastic plate base material are obtained, the morphology uniformity characterization parameter is determined based on the surface and edge cross-sectional images to determine whether the structural stability of the steel-plastic plate base material is qualified, and the temperature difference between the upper roller and the lower roller is determined according to the difference between the morphology uniformity characterization parameter and the preset morphology uniformity characterization parameter;

[0054] Step S3, the chemical conversion layer of the composite anticorrosion functional front film is prepared with the second galvanized layer of the steel-plastic plate base material with qualified structural stability to form a composite steel-plastic plate, wherein,

[0055] The second weather-resistant modified hot melt layer of the composite anticorrosion functional front film is in direct contact with the second galvanized layer, and the chemical layer is located on the outside of the front film.

[0056] In step S4, the spectral data of the composite steel-plastic plate are acquired, the interface wetting index is determined based on the spectral data, whether the layer bonding reliability of the composite anticorrosion functional front film and the steel-plastic plate substrate is qualified is determined, and the pressure or running speed of the laminating roller is adjusted according to the ratio of the interface wetting index to the preset interface wetting index.

[0057] In step S5, the surface profile data of the composite steel-plastic plate with qualified layer bonding reliability are acquired, the interface stress matching coefficient is determined based on the surface profile data, whether the stress balance of the composite steel-plastic plate is up to standard is determined, and the winding pressure of the tension roller is adjusted according to the relative difference between the preset interface stress matching coefficient and the interface stress matching coefficient.

[0058] In step S6, the high-weather-resistant fine-steel anticorrosion steel-plastic plate is obtained under the condition that the stress balance is up to standard.

[0059] Specifically, the application analyzes the structural stability of the steel-plastic plate substrate through the uniformity of the morphology, adjusts the temperature difference between the upper roller and the lower roller for the unstable steel-plastic plate substrate, then evaluates the bonding reliability of the front film and the substrate according to the interface wetting index and adjusts the laminating parameters for the unreliable composite steel-plastic plate, and finally determines the stress matching of the composite steel-plastic plate based on the interface stress matching coefficient, and adjusts the winding pressure to ensure stress balance when the stress matching is not matched.

[0060] The surface and cross-sectional image analysis can directly capture the interface wetting defects of the hot melt layer and the galvanized layer, dynamically adjust the temperature difference between the upper and lower rollers, ensure uniform coating of the molten resin on the metal substrate, improve the structural stability of the steel-plastic plate substrate, the characteristic wavelength change in the spectral data can quantify the bonding strength of the chemical conversion layer and the steel-plastic plate substrate, and the surface profile data analyze the stress concentration area, and the stress difference between the layers of the composite plate is balanced through the winding pressure compensation of the tension roller, which improves the consistency and reliability of the high-weather-resistant fine-steel anticorrosion steel-plastic plate, thereby improving the stability of the preparation of the high-weather-resistant fine-steel anticorrosion steel-plastic plate.

[0061] Please refer to Figure 2 As shown in the figure, it is a structural schematic diagram of the high-weather-resistant fine-steel anticorrosion steel-plastic plate according to the embodiment of the application.

[0062] The high-weather-resistant fine-steel anticorrosion steel-plastic plate according to the embodiment of the application comprises a steel plate layer 1, a first galvanized layer 2, a first weather-resistant modified hot melt layer 3, an anticorrosion back layer 4, a second galvanized layer 5, a second weather-resistant modified hot melt layer 6, a chemical conversion layer 7, and a weather-resistant anticorrosion heat-insulating surface layer 8.

[0063] Specifically, the preparation process of the composite anti-corrosion back film in the step S1 comprises: compounding the first weather-resistant modified hot melt layer and the first galvanized layer of the galvanized sheet through a double-roller hot compounding machine to form the composite anti-corrosion back film, wherein the upper roller temperature of the double-roller hot compounding machine is 195-205 DEG C, preferably 200 DEG C, the lower roller temperature is 180-190 DEG C, preferably 185 DEG C, the roller speed of the double-roller hot compounding machine is 2.5-3.5 m / min, preferably 3 m / min.

[0064] Specifically, the preparation process of the composite anti-corrosion back film in the step S1 comprises: compounding the first weather-resistant modified hot melt layer and the first galvanized layer of the galvanized sheet through a double-roller hot compounding machine to form the composite anti-corrosion back film, wherein the upper roller temperature of the double-roller hot compounding machine is 195-205 DEG C, preferably 200 DEG C, the lower roller temperature is 180-190 DEG C, preferably 185 DEG C, the roller speed of the double-roller hot compounding machine is 2.5-3.5 m / min, preferably 3 m / min.

[0065] Specifically, in the step S3, a winding tension roller is used to apply a winding pressure of 6-10 kN to the composite steel-plastic plate, wherein the winding pressure refers to the total pressure applied by the tension roller to the winding material, and the winding pressure is controlled by a hydraulic system.

[0066] Specifically, under the condition of determining the steel-plastic plate substrate, the industrial camera is used to acquire the surface and edge cross-sectional images of the steel-plastic plate substrate.

[0067] Please refer to Figure 3 Fig. 2 is a flow chart of determining whether the structural stability of the steel-plastic plate substrate is qualified according to the embodiment of the present application.

[0068] Specifically, according to the comparison result between the morphology uniformity characterization parameter determined according to the surface and edge cross-sectional images of the steel-plastic plate substrate and the preset morphology uniformity characterization parameter, it is determined whether the structural stability of the steel-plastic plate substrate is qualified.

[0069] When the morphology uniformity characterization parameter is less than or equal to the preset morphology uniformity characterization parameter, it is determined that the structural stability of the steel-plastic plate substrate is qualified.

[0070] When the morphology uniformity characterization parameter is greater than the preset morphology uniformity characterization parameter, it is determined that the structural stability of the steel-plastic plate substrate is unqualified.

[0071] In the embodiment of the present application, the preset topography uniformity characteristic parameter value range is [0.05, 0.15], preferably 0.1, but the above value is not limited thereto, and the skilled in the art can also adjust the value according to actual needs.

[0072] Specifically, the process of obtaining the topography uniformity characteristic parameter is to uniformly divide the surface image into a plurality of equal-area sub-regions;

[0073] The standard deviation of the gray scale of each sub-region is calculated, and the ratio of the average value of the standard deviation of the gray scale of all sub-regions to the maximum gray scale value is denoted as a surface gray scale uniformity index; the edge of the cross-sectional image is detected, the interface contour line is extracted, and a plurality of contour points are uniformly collected; the deviation value of each contour point from an ideal straight line is calculated, and the maximum deviation value is obtained; the ratio of the sum of squares of each deviation value to the number of contour points is divided by the maximum deviation value, and the result is denoted as a cross-sectional uniformity index; the topography uniformity characteristic parameter is the product of the surface gray scale uniformity index and the weight 0.6 plus the product of the cross-sectional uniformity index and the weight 0.4, wherein,

[0074] The size of the sub-region is determined based on the image resolution, and in the embodiment of the present application, for an image with a resolution of 1024x768 pixels, it is divided into 32x24 sub-regions, each sub-region has an area of 32x32 pixels, and the skilled in the art can adjust the number of sub-regions according to the pixel size to ensure that each sub-region can effectively reflect the local gray scale change.

[0075] It can be understood that the above sub-region division rule aims to ensure that each sub-region can capture meaningful local texture changes, and avoid noise amplification due to too small area or loss of details due to too large area. The skilled in the art can adaptively adjust the number of sub-regions according to the image resolution adopted, according to the principle that each sub-region contains about 1000 pixels, and the core is to ensure the stability and sensitivity of statistical analysis.

[0076] Specifically, in the condition that the structural stability of the steel-plastic plate substrate is determined to be unqualified, the temperature difference between the upper roller and the lower roller is determined according to the comparison result of the difference value between the topography uniformity characteristic parameter and the preset topography uniformity characteristic parameter and the preset difference value;

[0077] When the difference value is less than or equal to the preset difference value, it is determined that the temperature difference between the upper roller and the lower roller is increased to a corresponding value by a first preset temperature adjustment coefficient 1.05;

[0078] When the difference value is greater than the preset difference value, it is determined that the temperature difference between the upper roller and the lower roller is increased to a corresponding value by a second preset temperature adjustment coefficient 1.15;

[0079] Wherein, the difference value is the difference value between the topography uniformity characteristic parameter and the preset topography uniformity characteristic parameter.

[0080] In the embodiment of the present application, the preset difference value range is [0.3, 0.4], preferably 0.35, but the above-mentioned value is not limited thereto, and the skilled in the art can also adjust the value according to the actual needs.

[0081] In the embodiment of the present application, the increased temperature difference is the product of the temperature difference between the upper roller and the lower roller and the preset temperature adjustment coefficient, and the preset temperature adjustment coefficient includes a first preset temperature adjustment coefficient with a value of 1.05 and a second preset temperature adjustment coefficient with a value of 1.15. In order to ensure that the adjusted temperature difference meets the actual needs, the adjustment amplitude should not be too large, so the adjustment coefficient is correspondingly set to control the adjustment amplitude.

[0082] Specifically, the present application analyzes the morphology uniformity of the steel-plastic plate substrate through surface and cross-sectional image analysis, increases the temperature difference between the upper and lower rollers to optimize the infiltration effect of the hot melt layer when the uniformity does not meet the standard, evaluates the structural stability of the substrate according to the weighted integration of the surface gray uniformity reflecting the hot melt layer coverage uniformity and the cross-sectional profile deviation reflecting the interface bonding flatness, the low surface gray standard deviation indicates that the hot melt layer has no local accumulation or void, and the small cross-sectional profile deviation indicates that the galvanized layer and the hot melt layer interface have no wave or stratification, ensuring the reliability of the initial bonding of the substrate. The temperature difference between the upper and lower rollers affects the melting state and flow performance of the hot melt layer, increasing the temperature difference can improve the spreading ability of the hot melt layer on the surface of the galvanized layer, reduce the interface gap, and realize the compensation of the hot melt layer infiltration defects. Uniform morphology can block the penetration path of the corrosion medium and avoid local corrosion caused by interface defects, thereby improving the overall weather resistance.

[0083] Specifically, under the condition of determining the composite steel-plastic plate, the imaging instrument is used to acquire the spectral data of the composite steel-plastic plate.

[0084] Specifically, the embodiment of the present application determines whether the layer bonding reliability of the composite anti-corrosion functional front film and the steel-plastic plate substrate is qualified according to the comparison result of the interface infiltration index determined according to the spectral data of the composite steel-plastic plate and the preset interface infiltration index.

[0085] When the interface infiltration index is less than or equal to the preset interface infiltration index, it is determined that the layer bonding reliability of the composite anti-corrosion functional front film and the steel-plastic plate substrate is unqualified.

[0086] When the interface infiltration index is greater than the preset interface infiltration index, it is determined that the layer bonding reliability of the composite anti-corrosion functional front film and the steel-plastic plate substrate is qualified.

[0087] In the embodiment of the present application, the preset interface wetting index value range is [0.85, 0.95], preferably 0.9, but the above value is not limited thereto, and the skilled person in the art can also adjust the value according to the actual needs;

[0088] The interface wetting index is obtained by extracting the spectral reflectance data in the visible light range, identifying the characteristic wavelength interval representing good wetting, and in this embodiment, the reflectance in the 500mm-600mm interval is high, indicating good interface bonding;

[0089] The reflectance integral value in this interval is calculated, the full-waveband reflectance integral value is calculated, and the ratio of the reflectance integral value to the full-waveband reflectance integral value is denoted as the characteristic waveband proportion;

[0090] The spectral data is subjected to second derivative processing, and by comparing with the spectral database of known defect samples, a characteristic peak representing poor wetting is identified, wherein the poor wetting characteristic peak refers to a specific wavelength appearing in the second derivative spectrum, and in this embodiment, the specific wavelength is the peak value near 450mm or 700mm, and the amplitude exceeds a preset threshold, and in this embodiment, the second derivative absolute value is greater than 0.1, and is consistent with the spectral characteristics of known defect samples, and the number of such characteristic peaks is counted, and in this embodiment, the known defect samples are set as samples with bubbles and un-bonded areas;

[0091] The defect influence coefficient calculation formula is: defect influence coefficient = max(0, 1-characteristic peak number / preset maximum defect peak number), wherein the preset maximum defect peak number is set to 10, which is based on historical data statistics; in typical defect samples, the number of characteristic peaks is usually not more than 10; if the actual characteristic exceeds 10, the defect influence coefficient is 0, indicating that the wetting state is very poor;

[0092] Wherein, the interface wetting index is the product of the characteristic waveband proportion and the weight 0.7 plus the product of the defect influence coefficient and the weight 0.3.

[0093] It can be understood that the spectral database of known defect samples can be established by preparing standard samples with known wetting defects and collecting their spectral data. The specific wavelength is a characteristic waveband sensitive to the change of interface wetting state determined based on a large number of experimental observations;

[0094] The preset threshold is used to exclude noise interference and ensure that the identified characteristic peak has statistical significance;

[0095] The preset maximum defect peak number is set to 10, which is based on statistical analysis of more than 500 groups of historical defect sample data: 99% of the defect samples have no more than 10 characteristic peaks, and the setting ensures that the defect influence coefficient is in the interval [0, 1], and the value of 0 represents the worst interface wetting state, and the value of 1 represents no wetting defect characteristic peak. Those skilled in the art can adjust this preset value based on similar statistical analysis according to the production quality requirements.

[0096] Specifically, in the case that the composite anticorrosion function front film and the steel-plastic plate substrate are determined to be unqualified in terms of layer bonding reliability, the ratio of the interface wetting index to the preset interface weting index is compared with the preset ratio to determine whether to adjust the laminating roller pressure or the laminating roller speed;

[0097] When the ratio is less than or equal to the preset ratio, the laminating roller pressure is increased to a corresponding value by a preset pressure adjustment coefficient 1.2;

[0098] When the ratio is greater than the preset ratio, the laminating roller speed is reduced to a corresponding value by a preset speed adjustment coefficient 0.9.

[0099] The ratio is the ratio of the interface wetting index to the preset interface wetting index.

[0100] In the embodiment of the application, the preset ratio is in the range of [0.6, 0.7], preferably 0.65, but the above values are not limited thereto, and those skilled in the art can adjust the values according to actual needs.

[0101] In the embodiment of the application, the increased laminating roller pressure is the product of the laminating roller pressure and the preset pressure adjustment coefficient, and the value is 1.2; the reduced laminating roller speed is the product of the laminating roller speed and the preset speed adjustment coefficient, and the preset speed adjustment coefficient has a value of 0.9. In order to ensure that the adjusted laminating roller pressure or laminating roller speed meets the actual needs, the adjustment range should not be too large, so the adjustment coefficient is set to control the adjustment range.

[0102] It can be understood that the application adopts the strategy of adjusting a single key parameter in stages, which is based on a large number of experimental verification and process optimization results. In the steel-plastic plate substrate preparation stage, the temperature difference between the upper and lower rollers is the main factor affecting the flowability of the hot melt layer and the uniformity of the galvanized layer wetting, and other parameters (such as composite pressure and roller speed) have been fixed as the best values through previous optimization. In this embodiment, the composite pressure is set to 0.5 MPa, and the roller speed is set to 3 m / min.

[0103] Similarly, in the front film composite stage, the laminating roller pressure or speed is the most critical variable for controlling the interface bonding reliability, and the composite temperature is fixed at 195℃. By adjusting these key parameters, process fluctuations can be effectively compensated to ensure stable composite quality.

[0104] The weight and the adjustment coefficient are obtained by historical production data regression analysis, and reflect the sensitivity of the parameters to the performance. In the embodiment, the temperature difference adjustment coefficient 1.05 is suitable for slight structural defects, and 1.15 is suitable for serious defects, which are verified by experiments to effectively improve the structural stability.

[0105] The strategy of detecting and adjusting a single key parameter in stages is based on the system process optimization results of the Taguchi method and the single variable principle. In the early process development stage, through full-factor experimental design, the key process parameters (i.e. the parameters with the highest signal-to-noise ratio) that have the most significant impact on the final product quality in each composite stage have been determined, and the value range of other secondary parameters has been optimized and fixed.

[0106] Specifically, in the steel-plastic plate substrate preparation stage, through analysis of variance (ANOVA), it is confirmed that the temperature difference between the upper roller and the lower roller has a contribution rate of more than 65% to the uniformity of the morphology characterization parameter (representing the structural stability), which is much higher than other parameters (such as composite pressure and roller speed).

[0107] In the front film composite stage, it is also verified by experiments that the lamination roller pressure or speed has the most critical impact on the interface wetting index representing the layer bonding reliability.

[0108] Therefore, in the production process, by detecting the quality indicators online and dynamically adjusting the identified key parameters, the product quality can be efficiently and stably controlled. The weight and the adjustment coefficient are empirical values obtained by multiple linear regression analysis of historical production data, which can accurately reflect the quantitative relationship between the process parameters and the quality indicators.

[0109] Specifically, the present application determines whether the layer bonding reliability of the composite anticorrosion functional front film and the steel-plastic plate substrate is qualified by extracting the visible light range reflectivity and calculating the interface wetting index, and increases the lamination roller pressure or reduces the lamination roller speed when it is unqualified. The characteristic waveband proportion reflects the wetting degree of the chemical conversion layer and the substrate, and the characteristic waveband reflectivity integral is high when the wetting is good, and the proportion is large. The defect influence coefficient identifies the characteristic peaks caused by poor wetting through the second derivative of the spectrum, and the fewer the peaks, the higher the coefficient. After weighting, the interface wetting index comprehensively considers the effective coverage and defect control of the bonding interface, and quantifies the layer bonding reliability. Increasing the pressure can enhance the fluidity of the resin, promote the close contact of the film and the substrate, reduce the speed, prolong the hot pressing time, ensure the full wetting and solidification of the resin, and improve the interfacial bonding strength of the chemical conversion layer and the steel-plastic plate substrate. Good wetting can ensure that the anticorrosion functional film and the substrate form a continuous and dense protective layer, avoid the penetration of corrosive media due to delamination, and improve the anticorrosion and weather resistance of the steel-plastic plate.

[0110] Specifically, the embodiment of the present application determines the reliability of the layer bonding of the composite anticorrosion function front film and the steel-plastic plate substrate, and obtains the surface profile data of the composite steel-plastic plate through a profilometer.

[0111] Referring to Figure 4 The figure is a flow chart for determining whether the stress balance of the composite steel-plastic plate meets the standard according to the embodiment of the present application.

[0112] Specifically, the embodiment of the present application determines whether the stress balance of the composite steel-plastic plate meets the standard according to the comparison result of the interface stress matching coefficient obtained from the surface profile data and the preset interface stress matching coefficient.

[0113] When the interface stress matching coefficient is less than or equal to the preset interface stress matching coefficient, it is determined that the stress balance of the composite steel-plastic plate does not meet the standard.

[0114] When the interface stress matching coefficient is greater than the preset interface stress matching coefficient, it is determined that the stress balance of the composite steel-plastic plate meets the standard.

[0115] In the embodiment of the present application, the preset interface stress matching coefficient has a value range of [0.8, 0.9], and is preferably 0.85, but the above value is not limited thereto, and the skilled person in the art can also adjust the value according to actual needs.

[0116] Specifically, the process of obtaining the interface stress matching coefficient is to uniformly collect a plurality of edge points along the length direction of the composite steel-plastic plate, and to obtain the height values of the edge points; 1-(the ratio of the standard deviation of the curvature change rate to the average value of the curvature change rate) is the interface stress matching coefficient.

[0117] Specifically, the embodiment of the present application determines to adjust the winding pressure of the tension roller according to the comparison result of the relative difference between the preset interface stress matching coefficient and the interface stress matching coefficient and the preset relative difference when it is determined that the stress balance of the composite steel-plastic plate does not meet the standard.

[0118] When the relative difference is less than or equal to the preset relative difference, it is determined to reduce the winding pressure to a corresponding value by a first preset winding pressure optimization coefficient 0.95.

[0119] When the relative difference is greater than the preset relative difference, it is determined to reduce the winding pressure to a corresponding value by a second preset winding pressure optimization coefficient 0.85.

[0120] The relative difference is the relative difference between the preset interface stress matching coefficient and the interface stress matching coefficient, that is, the ratio of the absolute value of the difference between the preset interface stress matching coefficient and the interface stress matching coefficient to the preset interface stress matching coefficient.

[0121] In the embodiment of the present application, the preset relative difference value range is [0.2, 0.3], and the preferred value is 0.25, but the above value is not limited thereto, and the skilled person in the art can adjust the value according to the actual needs.

[0122] In the embodiment of the present application, the reduced winding pressure is the product of the winding pressure and the preset winding pressure optimization coefficient, and the preset winding pressure optimization coefficient includes a first preset winding pressure optimization coefficient with a value of 0.95 and a second preset winding pressure optimization coefficient with a value of 0.85. In order to ensure that the adjusted winding pressure meets the actual needs, the adjustment range should not be too large, so the adjustment range is controlled by setting the adjustment coefficient.

[0123] Specifically, in the embodiment of the present application, the high-weather-resistant fine steel anticorrosive steel-plastic plate is obtained under the condition that the stress balance of the composite steel-plastic plate meets the standard.

[0124] Specifically, the present application determines whether the stress balance of the composite steel-plastic plate meets the standard through the interfacial stress matching coefficient, and if it does not meet the standard, the tension roller winding pressure is reduced to optimize the stress balance between the layers. The curvature change rate reflects the deformation coordination of each layer of the composite plate and characterizes the uniformity of the interlayer stress distribution. By reducing the difference in tension between the layers, the internal stress caused by the different material shrinkage rates is balanced. The winding pressure of the tension roller affects the stress state of each layer of the composite plate during the winding process. Excessive winding pressure will exacerbate the stretching of the outer layer material, resulting in compression stress of the inner layer material due to limited shrinkage, and reducing the winding pressure can release the interlayer constraint, allowing each layer to complete stress relaxation in a natural state, avoiding interlayer peeling or surface warping caused by stress concentration. Balanced stress distribution can avoid the expansion of microcracks caused by temperature changes or mechanical loads during use, ensuring the long-term close combination of the anticorrosive functional film and the substrate, and improving the weather resistance and corrosion resistance of the steel-plastic plate.

[0125] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. The skilled person in the art can make equivalent changes or replacements to the related technical features without deviating from the principles of the present application, and the technical solutions after these changes or replacements will fall within the protection scope of the present application.

Claims

1. A method for preparing a high weather-resistant, high-precision steel anti-corrosion plastic sheet, characterized in that, include: The first weather-resistant modified hot-melt layer of the composite anti-corrosion back film and the first zinc coating layer of the galvanized sheet are used to prepare a steel-plastic composite substrate. The surface and edge cross-sectional images of the steel-plastic composite substrate are acquired. Based on the surface and edge cross-sectional images, a morphology uniformity characterization parameter is determined to determine whether the structural stability of the steel-plastic composite substrate is qualified. The temperature difference between the upper roller and the lower roller is adjusted according to the difference between the morphology uniformity characterization parameter and the preset morphology uniformity characterization parameter. A composite steel-plastic composite panel is prepared by bonding a composite anti-corrosion front film with a second galvanized layer of a steel-plastic composite panel substrate that meets structural stability requirements. The second weather-resistant modified hot-melt layer of the composite anti-corrosion front film is in direct contact with the second galvanized layer, while the chemical conversion layer is located on the outside of the second weather-resistant modified hot-melt layer. The preparation process of the composite anti-corrosion front film includes: uniformly coating the chemical conversion treatment liquid onto the surface of the second weather-resistant modified hot melt layer using a roller coater, and then drying and curing it in a curing oven to form a chemical conversion layer; and then laminating the second weather-resistant modified hot melt layer with the chemical conversion layer on its surface with the weather-resistant anti-corrosion and heat-insulating surface layer using a laminator to form the composite anti-corrosion front film. The spectral data of the composite steel-plastic composite board is obtained, and the interface wetting index is determined based on the spectral data to determine whether the layer adhesion reliability between the composite anti-corrosion functional front film and the steel-plastic composite board substrate is qualified. The pressure or speed of the laminating roller is adjusted according to the ratio of the interface wetting index to the preset interface wetting index. Obtain surface profile data of composite steel-plastic composite panels with qualified interfacial bonding reliability, determine the interfacial stress matching coefficient based on the surface profile data to determine whether the stress balance of the composite steel-plastic composite panels meets the standard, and determine the winding pressure of the tension roller according to the relative difference between the preset interfacial stress matching coefficient and the interfacial stress matching coefficient. High weather-resistant, high-strength steel anti-corrosion plastic sheet was obtained under the condition that the stress balance met the standard. The morphological uniformity characterization parameters are determined based on the surface grayscale uniformity index and the cross-sectional uniformity index; The interface wetting index is determined based on the proportion of characteristic bands and the defect influence coefficient. The interface stress matching coefficient is determined based on the standard deviation and average value of the rate of curvature change of the surface profile data of the composite steel-plastic composite board.

2. The method for preparing high weather-resistant, high-precision steel anti-corrosion steel-plastic composite panels according to claim 1, characterized in that, The structural stability of the steel-plastic composite substrate is deemed unqualified based on the comparison result of the morphological uniformity characterization parameter being greater than the preset morphological uniformity characterization parameter.

3. The method for preparing high weather-resistant high-precision steel anti-corrosion steel-plastic sheet according to claim 2, characterized in that, The process of adjusting the temperature difference between the upper and lower rollers includes: Calculate the difference between the morphology uniformity characterization parameter and the preset morphology uniformity characterization parameter under the condition that the structural stability of the steel-plastic composite substrate is unqualified. Based on the comparison result where the difference is less than or equal to a preset difference, the temperature difference between the upper and lower rollers is increased by a first preset temperature adjustment coefficient. Based on the comparison result where the difference is greater than a preset difference, the temperature difference between the upper and lower rollers is increased by a second preset temperature adjustment coefficient.

4. The method for preparing high weather-resistant, high-precision steel anti-corrosion steel-plastic sheet according to claim 3, characterized in that, The reliability of the bonding between the composite anti-corrosion front film and the steel-plastic composite substrate is unqualified, which is determined based on the comparison result that the interface wetting index is less than or equal to the preset interface wetting index.

5. The method for preparing high weather-resistant high-precision steel anti-corrosion steel-plastic sheet according to claim 4, characterized in that, The process of adjusting the pressure of the laminating roller includes: Calculate the ratio of the interface wetting index to the preset interface wetting index under the condition that the layer adhesion reliability between the composite anti-corrosion front film and the steel-plastic composite substrate is unqualified. The pressure of the laminating roller is increased based on the comparison result where the ratio is less than or equal to a preset ratio. The increased pressure of the laminating roller is determined based on the laminating roller pressure and the preset pressure adjustment coefficient.

6. The method for preparing high weather-resistant high-precision steel anti-corrosion steel-plastic sheet according to claim 5, characterized in that, The process of adjusting the speed of the laminating roller includes: Calculate the ratio of the interface wetting index to the preset interface wetting index under the condition that the layer adhesion reliability between the composite anti-corrosion front film and the steel-plastic composite substrate is unqualified. Based on the comparison results where the ratio is greater than a preset ratio, the speed of the laminating roller is reduced. The reduced speed of the laminating roller is determined based on the speed of the laminating roller and the preset speed adjustment coefficient.

7. The method for preparing high weather-resistant high-precision steel anti-corrosion steel-plastic sheet according to claim 6, characterized in that, The failure of the stress balance of the composite steel-plastic panel to meet the standard is determined based on the comparison result that the interface stress matching coefficient is less than or equal to the preset interface stress matching coefficient.

8. The method for preparing high weather-resistant high-precision steel anti-corrosion steel-plastic sheet according to claim 7, characterized in that, The process of adjusting the winding pressure of the tension roller includes: Calculate the relative difference between the preset interface stress matching coefficient and the interface stress matching coefficient under the condition that the stress balance of the composite steel-plastic composite panel is not up to standard; Based on the comparison results where the relative difference is less than or equal to the preset relative difference, the winding pressure is reduced by the first preset winding pressure optimization coefficient. Based on the comparison results where the relative difference is greater than the preset relative difference, the winding pressure is reduced by the second preset winding pressure optimization coefficient.

9. The method for preparing high weather-resistant high-precision steel anti-corrosion steel-plastic sheet according to claim 8, characterized in that, The preparation process of the composite anti-corrosion back film includes: combining the first weather-resistant modified hot melt layer with the first galvanized layer of the galvanized sheet through a two-roll hot composite machine to form a composite anti-corrosion back film.

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