Printing method, device, equipment and storage medium for realizing metallic color on general coated paper based on digital printing

Abstract

The present invention relates to a printing method, device, equipment and storage medium for realizing metallic color on universal coated paper based on digital printing. The method comprises: digitally partitioning the graphic area to be presented with metallic texture, and converting the CMYK dot ratio parameter of the graphic area into vector data to obtain a layered data file; performing UV adhesive oil spraying treatment to obtain a UV adhesive oil graphic layer; performing a first irradiation to obtain a pre-cured graphic area; performing a second irradiation to obtain a metallic graphic pattern; applying blue lacquer oil to the metallic graphic pattern to obtain a surface treatment layer; importing the CMYK digital graphic data in the layered data file into a digital printing device, and performing four-color ink dot printing on the surface treatment layer to obtain an image graphic with metallic texture. The implementation of the present invention accurately controls the curing degree of UV adhesive oil, the quality of silver foil lamination and the dyne value of blue lacquer oil, and ensures the stability of printing quality.

Description

Technical Field

[0001] The present invention relates to the technical field of digital printing, and in particular to a printing method, device, equipment and storage medium for realizing metallic color on general coated paper based on digital printing. Background Art

[0002] In the field of packaging printing, the printing effect of metallic colors is widely used in the design of product packaging to enhance the visual appeal and quality of the product. Traditional metallic color printing mainly relies on pre-modulated metallic spot color inks, which use silver ink as the main component and are mixed with other color inks to produce a single color spot color ink with a metallic texture.

[0003] However, this traditional printing method has obvious limitations. Each printing press color group can only print one metallic color. If multiple metallic colors need to be printed, multiple printing press color groups and multiple printing plates must be used, which not only increases production costs, but also fails to achieve a metallic texture pattern effect with color layers. In addition, the metallic brilliance of traditional silver ink is limited, which is far less ideal than the metallic reflective effect of silver foil. Summary of the invention

[0004] The main purpose of the present invention is to provide a printing method, device, equipment and storage medium for realizing metallic colors on universal coated paper based on digital printing. The present invention accurately controls the curing degree of UV adhesive oil, the laminating quality of silver foil and the dyne value of green lacquer oil, thereby ensuring the stability of printing quality.

[0005] To achieve the above object, the present invention provides a printing method for realizing metallic color on universal coated paper based on digital printing, comprising the following steps:

[0006] Digitally partitioning the graphic area that needs to present a metallic texture, and converting the CMYK dot ratio parameters of the graphic area into vector data to obtain a layered data file;

[0007] According to the layered data file, UV adhesive oil is sprayed on ordinary coated paper through the nozzle of the digital cold stamping equipment to obtain a UV adhesive oil graphic layer;

[0008] Inputting the UV adhesive oil pattern layer into a UV light curing device for a first irradiation, so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured pattern area;

[0009] The pre-cured graphic area is subjected to silver foil lamination by a pressure roller system and irradiated for a second time by a UV light source, so that the UV adhesive oil is completely cured and then excess silver foil is separated by a separation roller to obtain a metal graphic pattern;

[0010] Applying blue lacquer oil to the metal pattern by a coating machine, controlling the surface dain value of the metal pattern to be within a preset range, and obtaining a surface treatment layer;

[0011] The CMYK digital graphic data in the layered data file is imported into a digital printing device, and the surface treatment layer is printed with four-color ink dots to obtain an imaged graphic with a metallic texture.

[0012] The present invention also provides a printing device for realizing metallic color on general coated paper based on digital printing, comprising:

[0013] A conversion module, used for digitally partitioning the image and text area that needs to present a metallic texture, and converting the CMYK dot ratio parameters of the image and text area into vector data to obtain a layered data file;

[0014] A printing module, used for printing UV adhesive oil on ordinary coated paper through a nozzle of a digital cold stamping device according to the layered data file to obtain a UV adhesive oil graphic layer;

[0015] A first irradiation module is used to input the UV adhesive oil image layer into a UV light curing device for a first irradiation, so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured image area;

[0016] The second irradiation module is used to apply silver foil to the pre-cured graphic area through a pressure roller system and irradiate it for a second time through a UV light source, so that the UV adhesive oil is completely cured and then the excess silver foil is separated through a separation roller to obtain a metal graphic pattern;

[0017] A coating module, used for coating the metal pattern with blue lacquer oil through a coating machine, controlling the surface dain value of the metal pattern to be within a preset range, and obtaining a surface treatment layer;

[0018] The printing module is used to import the CMYK digital image data in the layered data file into a digital printing device, and perform four-color ink dot printing on the surface treatment layer to obtain an imaged image with a metallic texture.

[0019] The present invention also provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any one of the above methods when executing the computer program.

[0020] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned methods are implemented.

[0021] In summary, the present invention does not need to mix a variety of metal spot color inks, and can obtain a variety of metal color effects only by adjusting the CMYK dot ratio. At the same time, ordinary coated paper is used to replace expensive PET light silver cardboard, which significantly reduces the cost of raw materials. The platemaking link in the traditional process is eliminated, and the digital printing method is used for direct output, which reduces the machine adjustment loss and shortens the production cycle. By combining digital cold stamping technology with CMYK digital printing, the metal color level is richer, and the metal reflective effect of silver foil is better than traditional silver ink, which significantly improves the printing quality. Compared with the PET light silver cardboard printing process, the present invention only performs silver foil cold stamping in the area where the metal effect is required, and there is no need to use white ink to cover, which reduces material waste and is more environmentally friendly. Different metal color effects can be achieved by changing the CMYK dot ratio, and a combination of multiple metal colors can be printed on the same printed product. Using a digital control system, the curing degree of UV adhesive oil, the quality of silver foil lamination and the dyne value of green lacquer oil can be accurately controlled to ensure the stability of printing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the steps of a printing method for realizing metallic color on common coated paper based on digital printing in one embodiment of the present invention;

[0023] Figure 2 It is a structural block diagram of a printing device for realizing metallic color on common coated paper based on digital printing in one embodiment of the present invention;

[0024] Figure 3 It is a schematic block diagram of the structure of a computer device according to an embodiment of the present invention.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Reference Figure 1 This embodiment provides a method for printing metallic colors on general coated paper based on digital printing, comprising the following steps:

[0028] S1, digitally partitioning the image and text area that needs to present a metallic texture, and converting the CMYK dot ratio parameters of the image and text area into vector data to obtain a layered data file;

[0029] Among them, the area recognition analysis is performed on the image and text area that needs to present the metallic texture, and the boundary of the metallic texture area and the non-metallic texture area in the image and text is divided to form clear area recognition data. Data extraction is performed on the metallic texture area. By analyzing the color space of the metal area, it is converted into the CMYK color mode to obtain the CMYK color data of the area. The CMYK mode contains four color channels: cyan (C), magenta (M), yellow (Y) and black (K). The color intensity of each channel will affect the final printing effect. The dot ratio calculation is performed on the CMYK color data. By calculating the dot coverage of the four color channels, the specific coverage degree of each color is determined, and the dot ratio parameters of each channel are obtained. These parameters directly affect the ink superposition method and the final color presentation effect during the printing process. The dot ratio parameters are input into the vector conversion module, and the Bezier curve is used to fit the outline of the image and text, and the anchor point coordinates are generated. The Bezier curve is a mathematical curve used to accurately fit the outline of the image and text, generate smooth curves and edges, and provide accurate positioning basis for digital printing. By fitting the generated anchor point coordinates, the vector contour data of the image and text is obtained. Based on the vector contour data, the correlation mapping between the digital cold stamping silver foil layer and the printing layer is established to ensure that the silver foil layer and the printing layer can be accurately aligned so as to achieve the expected metal texture effect in the actual printing process. Through this mapping, the silver foil layer positioning data and the printing layer dot data are generated to form double-layer processing data, which clearly identifies the distribution mode of the silver foil and ink and their relative position relationship. The double-layer processing data is encapsulated according to the digital cold stamping process and the digital printing process to generate a layered data file containing the silver foil positioning information and the dot distribution information. The layered data file is used to control the workflow of the digital cold stamping equipment and the digital printing equipment to achieve accurate printing of metal texture images and texts.

[0030] S2, according to the layered data file, UV adhesive oil is sprayed on the ordinary coated paper through the nozzle of the digital cold stamping equipment to obtain a UV adhesive oil image layer;

[0031] Specifically, the silver foil layer positioning data in the layered data file is input into the control system of the digital cold stamping device. The device is enabled to generate a printing path data that completely matches the boundary of the graphic area according to the input positioning data. The printing path data is transformed into coordinates, and the absolute position coordinates of the nozzle are obtained by calculating the compensation parameters in consideration of the actual position and the existing errors of the ordinary coated paper, and the compensated positioning data are generated. The UV adhesive oil injection parameters of the digital cold stamping machine nozzle are adjusted according to the compensated positioning data. The injection amount and injection timing of the UV adhesive oil are controlled by the pulse control signal to ensure that each drop of UV adhesive oil can be accurately coated in the designed area. The control of the injection amount ensures that the thickness of each layer of adhesive oil is uniform, and the control of the injection timing can ensure that the timing and speed of each printing are accurate to form a uniform coating. Through these control signals, the execution unit of the digital cold stamping device can perform quantitative printing of UV adhesive oil at the specified position of the ordinary coated paper according to the set path and injection parameters, forming a UV adhesive oil coating that completely corresponds to the graphic area, and obtaining an initial UV adhesive oil layer. Check the quality and accuracy of the initial UV adhesive oil layer. Perform boundary scanning on the contour of the initial UV adhesive oil layer. By scanning the edge of the layer, the position information and thickness data of the edge of the layer are collected to obtain the layer detection data, which helps to evaluate the boundary accuracy and thickness uniformity of the coating. Evaluate the accuracy of the initial UV adhesive oil layer through the digital calibration algorithm. The digital calibration algorithm can analyze the layer detection data, identify areas with uneven coating or inaccurate contours, and correct them through re-spraying technology to ensure the uniformity and accuracy of the coating. The re-spraying process fine-tunes the spray parameters of the nozzle and performs precise re-spraying on uneven areas to ensure that the coating thickness of each part is consistent, so as to obtain the UV adhesive oil graphic layer.

[0032] S3, inputting the UV adhesive oil pattern layer into a UV light curing device for a first irradiation, so that the UV adhesive oil is cured to a preset curing degree, and a pre-cured pattern area is obtained;

[0033] It should be noted that the UV adhesive oil graphic layer that has been sprayed is transported to the UV light curing device. The feeding position of the UV adhesive oil graphic layer is accurately positioned by the sensing system to obtain the UV adhesive oil positioning data. The UV adhesive oil positioning data is analyzed, and the expected degree of curing is set between 60% and 80% in combination with the irradiation parameters of the UV light source. The setting of the curing range is adjusted according to actual needs and the characteristics of the UV adhesive oil to ensure that the layer after preliminary curing has appropriate viscosity so that the subsequent steps can continue smoothly. The UV light source irradiation scheme is input into the control unit of the UV light curing device. Through the instructions of the control unit, the UV light source irradiates the UV adhesive oil graphic layer for the first time. At this stage, the intensity, duration and other parameters of the light source irradiation are adjusted according to the preset scheme to ensure that the curing degree of the UV adhesive oil meets the target range and forms an initial cured layer. The initial cured layer is tested for curing state. The surface state parameters of the curing area, including the surface gloss and uniformity of the cured layer, are collected by the optical imaging system to help judge the actual state of the cured layer and whether the expected curing effect is achieved uniformly. The curing degree of the UV adhesive oil is calculated based on the curing status data and compared with the set curing range. If the curing degree is detected to be insufficient or uneven, the UV light intensity is compensated. The generation of compensation data is based on comparative analysis, and the areas that are not fully cured are supplemented by adjusting the irradiation intensity and irradiation time. The goal of supplementary irradiation is to cure the adhesive oil to the set range of 60%-80% to ensure that the curing effect of the adhesive oil is uniform. By correcting the compensation data, the UV light source performs additional irradiation on the areas that have not been fully cured to ensure that the entire UV adhesive oil graphic layer evenly reaches the predetermined curing target to form a pre-cured graphic area.

[0034] S4, applying silver foil to the pre-cured graphic area through a pressure roller system and irradiating it for a second time with a UV light source, so that the UV adhesive oil is completely cured and then the excess silver foil is separated by a separation roller to obtain a metal graphic pattern;

[0035] Specifically, the pre-cured image area is transported and positioned. Multiple sets of sensors are used to monitor and record the position of the pre-cured image area in real time, and data is collected with the position of the transfer silver foil to obtain position matching data to ensure the accurate docking of the transfer silver foil and the pre-cured image area. The pressure parameters of the pressure roller system are set based on the position matching data. According to the specific conditions of the image area, the appropriate pressure parameters are synchronized to the pressure roller drive device through the digital control system. Through precise pressure control, it is ensured that the silver foil can evenly cover the entire pre-cured image area during the lamination process to obtain a silver foil pre-lamination layer. The silver foil pre-lamination layer is irradiated with a UV light source for the second time. Through the UV light source control system, the UV adhesive oil is completely cured to 100%, so that the UV adhesive oil is completely cured, ensuring that the silver foil layer is completely attached to the surface of the substrate and has sufficient adhesion to prevent the silver foil from falling off or unevenness during subsequent processing. After the curing is completed, the tension of the cured lamination layer is controlled by the separation roller system, and the excess transfer silver foil film is peeled off at a fixed angle and speed to obtain an accurate silver foil image layer. The tension control of the separation roller ensures that the silver foil film can be peeled off smoothly and steadily without causing any damage to the solidified graphic area. The quality of the silver foil graphic layer is inspected. The image scanning system collects the surface data of the silver foil graphic layer in real time, analyzes and evaluates the integrity of the silver foil attachment area, detects whether the silver foil is evenly attached to the graphic area, and promptly discovers potential defects or problems to ensure that the quality of each product meets the standards. A complete metal graphic pattern is obtained.

[0036] S5, coating the metal pattern with blue lacquer oil by a coating machine, controlling the surface dain value of the metal pattern to be within a preset range, and obtaining a surface treatment layer;

[0037] Among them, the surface state of the metal pattern is scanned. The metal glossiness of the silver foil attachment area is detected by a surface analyzer to obtain surface characteristic data, and provide information such as glossiness and uniformity of the coating layer surface. According to the surface characteristic data, the coating thickness of the green lacquer oil is calculated to generate a corresponding relationship curve between the coating amount and the dyne value. The dyne value is an important indicator for measuring the adhesion of ink. Controlling the range of this value can ensure that the green lacquer oil is evenly coated on the surface of the silver foil and has appropriate adhesion and gloss. Through a precision coating machine, according to the calculated coating amount and dyne value requirements, the surface of the metal pattern is quantitatively coated to ensure the uniformity and consistency of the coating layer, and a green lacquer oil coating is obtained. The surface dyne value of the green lacquer oil coating is dynamically monitored. Through the online detection system, the dyne value data of the coating surface is collected in real time to evaluate whether the actual dyne value of the coating layer is within the preset range. The preset range is 38 to 42, which ensures that the adhesion of the coating layer is in the best state. If the monitoring results show that the dyne value of the coating does not reach the preset range, adjustments are made to ensure that the quality of the coating layer meets the standard. During the coating process, the online detection system continuously feeds back the dyne value measurement data to the control system so as to adjust the coating amount of the coater in real time to ensure that the dyne value of the coating layer is always maintained within the preset range. According to the dyne value measurement data, the coating system adjusts the coating amount in real time and ensures that the coating layer is always within the optimal adhesion range through precise control. The adjusted coating amount will be reflected in the operation of the coater to form the dyne value control data. After analysis, these data are used to evaluate the quality control of the coating process to ensure that each coating process meets the requirements. The quality control system of the coater uses control data to monitor and adjust the entire coating process to ensure that the coating on each piece of paper is uniform and stable, and finally obtain a surface treatment layer that meets the requirements.

[0038] S6, importing the CMYK digital image data in the layered data file into a digital printing device, performing four-color ink dot printing on the surface treatment layer, and obtaining an image with a metallic texture.

[0039] Specifically, the CMYK digital graphic data in the layered data file is imported into the digital printing device. The dot coverage parameters of each CMYK ink are extracted through the digital analysis system to obtain the ink layering data. The ink layering data is digitally processed. The overprinting dot size of the CMYK four-color ink required for each area is calculated through the ink supply system of the four-color printing unit. By calculating the size of the ink overprinting dots in each area, it is ensured that the combination of each color ink can form an accurate color layer on the surface treatment layer while retaining the reflective characteristics of the metal texture area. The calculated dot size and coverage ratio constitute the dot control parameters, which directly affect the printing quality and the presentation of the final effect. Through the precise control of the dots, the metal texture of the treatment layer is avoided from being completely covered by the ink, and through appropriate overprinting, the metal surface can still transmit reflections, presenting a pattern effect with a rich metal texture. The print head of the digital printing device is set according to the dot control parameters. The adjustment of the inkjet amount and dot size of the print head is a key factor to ensure that the printing effect meets expectations. The inkjet volume setting determines the amount of ink deposited in each area, while the dot size determines the distribution and effect of the ink on the paper. If the inkjet volume is too much, the ink will be over-covered, thereby covering the metal color; if the inkjet volume is too little, the metal texture cannot be effectively displayed. Through precise parameter settings, ensure that the ink overprinting and dot size are appropriate, so that the ink cannot completely cover the metal texture of the treatment layer, and ensure that the metallic luster and color layering are fully reflected. Input the printing control data into the digital printing system to guide the actual printing process. The digital printing equipment performs color separation and overprinting of the surface treatment layer with four-color ink according to the input printing control data. Through the combination of dots in different proportions, the ink presents a rich color effect on the paper, and at the same time can also transmit the reflection of the silver foil. This design method can achieve a gradient effect of metallic color through layered dot printing, presenting a picture with a metallic texture. After printing is completed, the picture quality of the metallic color layer is scanned and monitored in real time. Through the image detector, the dot size and metal reflectivity of each area are collected, and these data are used to evaluate whether the picture quality meets the set standards. The image detector detects any quality deviation caused by improper printing parameters or equipment failure, such as inconsistent dot size or uneven metal reflective effect. Based on the collected quality monitoring data, the printing system's printing parameters are compensated and adjusted to ensure that the metal effect and color effect of each area can meet the set requirements. Through continuous quality monitoring and adjustment, it can ensure that each batch of printed graphics can meet high quality standards and obtain images with a metallic texture.

[0040] In one example, the graphic area that needs to present a metallic texture is digitally partitioned, and the CMYK dot ratio parameters of the graphic area are converted into vector data to obtain a layered data file, including:

[0041] Performing regional recognition analysis on the image and text area that needs to present a metallic texture, and dividing the boundaries between the metallic texture area and the non-metallic texture area to obtain regional recognition data;

[0042] Extract data from the metal texture area according to the area recognition data, set the color space parameter of the metal texture area to CMYK mode, and obtain CMYK color data;

[0043] Calculate the dot ratio of CMYK color data, and obtain the dot ratio parameters by calculating the dot coverage of the four channels of cyan, magenta, yellow and black;

[0044] Input the dot ratio parameters into the vector conversion module, perform Bezier curve fitting on the outline of the graphic and generate anchor point coordinates to obtain vector outline data;

[0045] Based on the vector contour data, the correlation mapping between the digital cold stamping silver foil layer and the printing layer is established to generate the silver foil layer positioning data and the printing layer dot data to obtain the double-layer processing data;

[0046] The double-layer processing data is packaged according to the digital cold stamping process and the digital printing process to generate a layered data file containing silver foil positioning information and dot distribution information.

[0047] In this example, the region recognition analysis is performed on the image and text area that needs to present a metallic texture. Identify which parts of the image and text area should show a metallic texture and which parts do not. Use edge detection algorithms, color segmentation algorithms, or deep learning models to achieve accurate region recognition. Through these algorithms, the boundaries of the metallic texture area and the non-metallic texture area are clearly divided, and a region recognition data file containing the metallic texture area and the non-metallic texture area is obtained. The file records the location, shape, and attribute information of each area. Based on the region recognition data, data extraction is performed on the metallic texture area. The specific information of the metallic texture area is extracted from the region recognition data, and the color space of these areas is converted into CMYK mode. CMYK mode is a color model commonly used in the printing process, which consists of four colors: cyan (C), magenta (M), yellow (Y), and black (K). For each pixel, its CMYK value consists of the values ​​of four channels, indicating the ink coverage ratio of different color channels. For example, at a certain pixel in an image, assuming that the CMYK value is C=0.5, M=0.3, Y=0.1, K=0.0, this means that the color of the pixel is composed of 50% cyan, 30% magenta, 10% yellow, and no black ink is used. This conversion can convert the color space of the image area from RGB (red, green, blue) or other color modes to the CMYK mode suitable for printing, so that the color effect of the original pattern can be accurately reproduced during the printing process. Perform dot ratio calculation on the CMYK color data of the metallic texture area. Calculate the dot coverage of the four channels of cyan, magenta, yellow and black. The dot ratio calculation determines the coverage of each color ink in the final print. The printing press controls the depth and saturation of the printed color by adjusting the dot coverage ratio of each ink. The ratio parameter directly affects the distribution of ink and the effect of the image during the printing process. By calculating the dot ratio and adjusting the ratio of each ink channel, the required color level and brightness effect can be achieved. Input the dot ratio parameter into the vector conversion module. The vector conversion module converts the outline of the graphic from raster data (pixel data) to vector data. Vector data is used for high-precision graphics generation and processing, in which the edges of the graphics are described by mathematical formulas rather than pixelated images. The vectorization process is performed through Bezier curve fitting, which is a curve fitting method applied in computer graphics that can accurately describe the shape of the curve through control points and parameterized equations of the curve. By fitting the outline of the graphic with Bezier curves, the precise path of the graphic is generated, and the vector outline data is formed by calculating the anchor point coordinates of each path. Based on the vector outline data, the association mapping of the digital cold foil silver foil layer and the printing layer is established to ensure the precise alignment of the silver foil layer and the printing layer, so that in the actual cold foil and printing process, the silver foil can be covered in the correct position, while ensuring that the printed pattern can be accurately presented. By comparing the vector data of the silver foil layer and the printing layer, the positioning data of the silver foil layer and the dot data of the printing layer are generated to form double-layer processing data.According to the requirements of digital cold stamping process and digital printing process, the double-layer processing data is encapsulated to generate a layered data file containing silver foil positioning information and dot distribution information.

[0048] Among them, the dot ratio of CMYK color data is calculated, and the dot ratio parameter is obtained by calculating the dot coverage of the four channels of cyan, magenta, yellow and black, including: inputting the CMYK color data into the feature extraction network for channel separation, the feature extraction network contains five convolution layers, each convolution kernel size is 3×3, the step size is 1, the padding is 1, and each layer is followed by a BatchNorm layer and a ReLU activation function to obtain the initial feature map of the four channels; the initial feature map is feature enhanced by the residual enhancement network, the residual enhancement network contains 8 residual blocks, each residual block is composed of two convolution layers, and the convolution kernel size is 1×3. The size of the network is 3×3, and an SE attention module is added in the middle. The compression ratio of the attention module is 16 to obtain an enhanced feature map; a feature pyramid network is constructed based on the enhanced feature map, and top-down feature fusion is performed through feature layers of 1 / 1, 1 / 2, and 1 / 4 scales. Each scale layer is channel-adjusted through 1×1 convolution, and bilinear interpolation is used for upsampling to obtain a multi-scale feature representation; the multi-scale feature representation is input into the dot prediction network, which contains four parallel branches, each of which contains three fully connected layers with 1024, 512, and 256 nodes respectively, and a random inactivation layer with a Dropout rate of 0.5 is used to prevent Stop overfitting and get the initial dot distribution; Binarize the initial dot distribution using the OTSU adaptive threshold algorithm, remove noise through morphological opening operation, fill holes through closing operation, calculate the ratio of the total dot area of ​​each channel to the canvas area, and get the dot coverage data; Based on the dot coverage data, establish a dot compensation model through a four-layer fully connected neural network. The input layer of the model is 16 nodes, including the original coverage of the four channels of CMYK and their two-by-two combinations, the number of hidden layer nodes is 32 and 16, and the output layer is 4 nodes corresponding to the corrected coverage, and get the compensated dot data; Input the compensated dot data into U -Net optimization network, U-Net contains 4 layers of encoder and 4 layers of decoder. The encoder adopts 3×3 convolution downsampling with stride, and the decoder adopts deconvolution upsampling. Skip connections are added between corresponding layers to retain edge details to obtain the optimized dot distribution. The optimized dot distribution is integrated through the attention weighted fusion module. The module first calculates the attention weights of the four channels. The weights are obtained by 1×1 convolution plus Softmax normalization, and then the weights are multiplied and superimposed with the dot distribution of the corresponding channel. Finally, the value is normalized to the range of 0-1 through the Sigmoid function to obtain the final dot ratio parameter.

[0049] In one example, UV adhesive oil is sprayed on ordinary coated paper through the nozzle of a digital cold stamping device according to the layered data file to obtain a UV adhesive oil graphic layer, including:

[0050] Input the silver foil layer positioning data in the layered data file into the control system of the digital cold stamping equipment to generate printing path data that fully matches the boundary of the graphic area;

[0051] The coordinate transformation of the printing path data is performed, and the absolute position coordinates of the nozzle are calculated according to the position compensation parameters of ordinary coated paper to obtain the compensated positioning data;

[0052] According to the compensated positioning data, the UV adhesive oil injection parameters of the digital cold stamping machine nozzle are adjusted, and the injection amount and injection timing of the UV adhesive oil are controlled by the pulse control signal to obtain the injection control signal;

[0053] Input the jet control signal into the execution unit of the digital cold stamping equipment, perform quantitative spraying of UV adhesive oil at the designated position of the ordinary coated paper, form a UV adhesive oil coating that completely corresponds to the graphic area, and obtain an initial UV adhesive oil layer;

[0054] Perform boundary scanning on the outline of the initial UV adhesive oil layer, collect the position information and thickness data of the edge of the layer, and obtain the layer detection data;

[0055] The contour accuracy and coating uniformity of the initial UV adhesive oil layer are evaluated according to the layer detection data, and the uneven areas are corrected and re-sprayed through the digital calibration algorithm to obtain the UV adhesive oil graphic layer.

[0056] In this example, the silver foil layer positioning data in the layered data file is input into the control system of the digital cold foil equipment to generate printing path data that fully matches the boundary of the graphic area. The silver foil layer positioning data defines the specific position and shape of the silver foil coverage, while the printing path data indicates how the UV adhesive oil should be accurately printed on the coated paper. The printing path data is transformed into coordinates, and the absolute position coordinates of the nozzle are calculated through the position compensation parameters. The position compensation parameters are obtained by analyzing the feedback signal of the paper feeding system, taking into account the deviation of the paper during the transmission process. The compensated coordinates ensure that the nozzle is accurately aligned with the target position on the coated paper, thereby avoiding printing errors caused by paper position deviation. The UV adhesive oil injection parameters of the digital cold foil machine nozzle are adjusted according to the compensated positioning data. In order to ensure that the printing effect of the UV adhesive oil meets the requirements, the injection amount and injection timing of the nozzle are controlled. The injection amount determines the amount of ink ejected by each nozzle per unit time, while the injection timing controls the rhythm and time interval of the ink ejection. In the digital cold foil equipment, the injection amount and timing are realized by pulse control signals, which determine the switching frequency and injection timing of the nozzle. By adjusting these parameters, it is ensured that each nozzle sprays an appropriate amount of UV adhesive oil in the specified area and forms a uniform coating. The spray timing controls the interval time of the spray by adjusting the pulse frequency to ensure the accuracy and uniformity of the coating. The spray control signal is input into the execution unit of the digital cold stamping equipment to guide the nozzle to perform quantitative spraying of UV adhesive oil at the specified position of the ordinary coated paper according to the set parameters. During the spraying process, the UV adhesive oil will form a coating that completely matches the design on the graphic area to obtain the initial UV adhesive oil layer. The contour of the initial UV adhesive oil layer is scanned to monitor the accuracy of the coating in real time to ensure that the boundary of the coating is completely consistent with the graphic area. The position information of the coating edge is obtained through the image scanning system, and the thickness data of the coating is collected to obtain the layer detection data. The layer detection data includes the thickness value and position coordinates of each scanning point. According to the layer detection data, the contour accuracy and coating uniformity of the initial UV adhesive oil layer are evaluated. The uneven area of ​​the coating is corrected by the digital calibration algorithm. By adjusting the spray volume and spray timing, the thickness and distribution of the coating are ensured to be more uniform. The calibration algorithm uses real-time monitoring data to identify deviations in the coating and corrects these deviations by adjusting the nozzle parameters. By adjusting the amount of additional spraying, the unevenness of the coating is minimized, resulting in a smoother and more uniform UV adhesive oil graphic layer.

[0057] In one example, the UV adhesive oil pattern layer is input into a UV light curing device for a first irradiation, so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured pattern area, including:

[0058] The UV adhesive oil pattern layer is transported to the UV light curing device, and the feeding position of the UV adhesive oil pattern layer is positioned by the sensor system to obtain the UV adhesive oil positioning data;

[0059] The UV adhesive oil positioning data was analyzed, and the curing degree was set to 60%-80% according to the UV light source irradiation parameters to obtain the UV light source irradiation plan;

[0060] Inputting the UV light source irradiation scheme into the control unit of the UV light curing device, starting the UV light source to irradiate the UV adhesive oil image layer for the first time, and obtaining an initial cured layer;

[0061] Performing a curing state test on the initial curing layer, collecting surface state parameters of the curing area through an optical imaging system, and obtaining curing state data;

[0062] Calculate the curing degree of UV adhesive oil according to the curing state data, and compensate for UV light intensity by comparing the set curing range to obtain curing compensation data;

[0063] The curing compensation data is corrected, and the UV adhesive oil reaches the target state of the first curing through the supplementary irradiation of the UV light source to obtain the pre-cured graphic area.

[0064] In this example, the UV adhesive oil image layer is transported to the UV light curing device. The position of the UV adhesive oil image layer is monitored in real time by the device's sensor system to ensure accurate alignment of the image layer. The sensor system captures each position of the image layer during the feeding process through photoelectric sensors or image recognition technology to form accurate positioning data. The data is usually expressed in the form of two-dimensional coordinates, describing the exact position of each layer of ink. The UV adhesive oil positioning data is analyzed to set the degree of curing of the UV light source. The intensity and time of the UV light source are the key to ensure uniform curing of the adhesive oil. The degree of curing needs to be controlled within the range of 60%-80% to ensure that the coating has sufficient adhesion but not over-cured, resulting in a decrease in the performance of the adhesive oil or brittleness. During the analysis process, the device calculates the appropriate irradiation parameters, including irradiation time, light source power, and irradiation uniformity, based on the actual position and material properties of the image layer to ensure that the curing effect reaches the expected range. Through calculation, a UV light source irradiation plan is generated and transmitted as input data to the control unit of the UV light curing device. After receiving the irradiation scheme, the control unit starts the UV light source to irradiate the UV adhesive oil graphic layer for the first time. Through a certain irradiation intensity and time, the UV adhesive oil is initially cured to form an initial cured layer. The light source power and irradiation time during the irradiation process are determined by actual tests. These parameters determine the initial curing effect of the adhesive oil on the graphic layer. After the initial curing is completed, the curing state is detected. The curing area is scanned by an optical imaging system to collect surface state parameters such as surface gloss, uniformity and degree of curing. Each area is scanned by a high-precision camera or sensor to generate a curing state data file to record the curing status of each position. According to the curing state data, the actual curing degree of the UV adhesive oil is calculated and compared with the set curing range. Through comparison, areas with insufficient or excessive curing are found, and the required compensation data is calculated. The compensation data refers to adjusting parameters such as UV light intensity and irradiation time to ensure that the curing degree of all areas can be maintained within the ideal range of 60%-80%. Through calculation, the UV light intensity that needs to be supplemented for each area is determined, and the irradiation scheme is adjusted. After correcting the curing compensation data, the UV light source is started for supplementary irradiation. By adjusting the irradiation time and light source power, the curing degree of the adhesive oil is ensured to reach the predetermined target. After multiple scans and corrections, the gloss, adhesion and layering of the cured area are all in an ideal state. After the additional irradiation, the adhesive oil graphic layer completes the first curing, forming a pre-cured graphic area.

[0065] The curing degree of the UV adhesive oil is calculated according to the curing state data, and the UV light intensity compensation is performed by comparing the set curing range to obtain the curing compensation data, including: inputting the curing state data into the first detection module, collecting the numerical value of the surface viscosity of the UV adhesive oil, and obtaining the first viscosity value; performing range analysis on the first viscosity value, setting the threshold parameter according to the preset 60%-80% curing interval, and obtaining the first threshold data; inputting the first threshold data into the light intensity calculation unit, determining the deviation value according to the current curing degree of the UV adhesive oil, and obtaining the first correction parameter; performing light intensity conversion on the first correction parameter, generating the compensation amount through the UV energy density calculation formula, and obtaining the first compensation value; adjusting and calculating the irradiation power of the UV light source based on the first compensation value, generating a power adjustment instruction, and obtaining the second compensation value; calculating the irradiation time according to the second compensation value, converting the compensation amount into an accurate time series, and obtaining the time control data; inputting the time control data into the UV light source controller, generating the accurate power supply parameters of the UV lamp, and obtaining the power control data; integrating and processing the power control data to form a complete UV irradiation compensation scheme, and obtaining the curing compensation data.

[0066] In one example, the pre-cured graphic area is silver-foiled by a pressure roller system and irradiated for a second time by a UV light source, so that the UV adhesive oil is completely cured and then the excess silver foil is separated by a separation roller to obtain a metal graphic pattern, including:

[0067] The pre-curing image and text area is transmitted and positioned, and data of the pre-curing image and text area and the position of the transferred silver foil are collected through multiple sets of sensors to obtain position matching data;

[0068] The pressure parameters of the pressure roller system are set based on the position matching data, and the pressure distribution parameters are synchronized to the pressure roller driving device through the digital control system to obtain the pressure control data;

[0069] According to the pressure control data, the pressure roller system is driven to operate, so that the transfer silver foil is fully laminated with the pre-cured graphic area to obtain a silver foil pre-laminated layer;

[0070] The silver foil pre-lamination layer is irradiated with UV light source for the second time, and the UV adhesive oil is completely cured to 100% by the UV light source control system to obtain a cured lamination layer;

[0071] The tension of the cured bonding layer is controlled by a separation roller system, and the excess transfer silver foil film is peeled off at a fixed angle and speed to obtain a silver foil image layer. The surface of the silver foil image layer is then quality inspected, and the integrity of the silver foil attachment area is analyzed and evaluated by image scanning to obtain a metal image pattern.

[0072] In this example, the pre-cured graphic area is transferred and positioned, and data is collected through multiple sets of sensors to ensure that the alignment between the graphic area and the transferred silver foil is accurate. The sensor system generates position matching data by real-time monitoring of the displacement of the paper and the relative position of the silver foil to describe the spatial relationship between the pre-cured graphic area and the silver foil. During the data collection process, the output signal of the sensor is a continuous photoelectric signal or image information, which can provide accurate position data after conversion. The pressure parameters of the pressure roller system are set based on the position matching data. The pressure roller system is used to press the silver foil on the pre-cured graphic layer, and its pressure distribution directly affects the adhesion effect of the silver foil. In order to ensure that the silver foil can be evenly and firmly attached to the graphic area, the pressure parameters are accurately adjusted through the digital control system. The pressure distribution parameters of the pressure roller system are adjusted according to factors such as the complexity of the graphic area, the material of the silver foil, and the thickness of the pre-cured adhesive layer. By adjusting the total pressure and contact area, the pressure intensity of each area is accurately controlled to ensure the perfect fit of the silver foil and the graphic area. After the pressure control data is input into the digital control system, the pressure roller system operates according to these data to make the transfer silver foil fully bonded with the pre-cured graphic area to form a pre-bonded layer of silver foil. The core of this process is the uniform application of pressure to ensure that the silver foil completely covers the graphic area and there are no bubbles or gaps to avoid defects during the bonding process. The silver foil pre-bonded layer is subjected to a second UV irradiation, and the UV adhesive oil is completely cured to 100% through the UV light source control system. The purpose of the second irradiation is to fully cure the adhesive oil to ensure the firm adhesion of the silver foil on the graphic layer. In order to ensure the curing effect, the irradiation intensity and time of the UV light source must be precisely controlled and set according to the size of the graphic area, the thickness of the adhesive oil and the curing requirements. By calculating and controlling these parameters, the UV adhesive oil will be completely cured to ensure its stability and adhesion. The tension of the cured bonding layer is controlled by the separation roller system. The main function of the separation roller is to control the peeling process of the silver foil film so that the excess transfer silver foil film can be peeled off at a fixed angle and speed to obtain the final silver foil graphic layer. The tension control of the separation roller can ensure that the silver foil film will not tear or produce bubbles during the peeling process, ensuring the integrity of the silver foil image layer. The basic principle of tension control is to adjust the speed and pressure of the roller to keep the silver foil film at a constant tension during the peeling process to avoid uneven peeling effects. By precisely controlling the tension, the peeling process is ensured to be smooth and the silver foil image layer is obtained. The quality of the silver foil image layer is inspected. The surface image of the silver foil attachment area is collected by the image scanning system, and its integrity is analyzed to obtain the metal image pattern. Check whether the silver foil is evenly attached, whether there are areas where the peeling is incomplete, or whether there are defects such as bubbles and wrinkles. The inspection system uses a high-resolution camera to scan the image and generate quality assessment data for each area. Through quality assessment, problems in production can be discovered and corrected in a timely manner to ensure that the quality of each image layer meets the requirements.

[0073] In one example, a metal pattern is coated with blue lacquer oil by a coating machine, and the surface dyne value of the metal pattern is controlled within a preset range to obtain a surface treatment layer, including:

[0074] Scan the surface state of the metal pattern, and use a surface analyzer to detect the metal glossiness of the silver foil attachment area to obtain surface characteristic data;

[0075] The coating thickness of the green lacquer oil is calculated according to the surface characteristic data, and a corresponding relationship curve between the coating amount and the dyne value is generated. The green lacquer oil is quantitatively coated on the surface of the metal pattern through a precision coating machine to control the uniformity of the coating layer and obtain a green lacquer oil coating;

[0076] Dynamically monitor the surface Diyan value of the green lacquer oil coating, collect the Diyan value data of the coating surface through the online detection system, judge whether it is within the preset range, and obtain the Diyan value measurement data, the preset range is 38-42;

[0077] The coating amount of the coating system is adjusted in real time according to the dyne value measurement data to ensure that the dyne value of the coating layer is maintained within the preset range, and the dyne value control data is obtained. The dyne value control data is analyzed, and the surface treatment quality is evaluated through the quality control system of the coater to obtain the surface treatment layer.

[0078] In this example, the surface state of the metal pattern is scanned. The surface analyzer detects the metallic glossiness of the silver foil attachment area to obtain surface characteristic data. The surface analyzer uses optical imaging technology and combines the reflective characteristics of the metal surface to accurately measure the glossiness, reflectivity and surface uniformity of the silver foil layer in different areas. The coating thickness of the green lacquer oil is calculated based on the surface characteristic data. During the green lacquer oil coating process, there is a certain relationship between the coating amount and the Diane value. The coating thickness is calculated based on the surface characteristic data. The Diane value is used to measure the glossiness of the surface paint or coating. The higher the value, the brighter the surface. When calculating the coating amount of green lacquer oil, a corresponding relationship curve between the coating amount and the Diane value is generated. The relationship curve shows that an increase in the coating amount usually leads to an increase in glossiness until a saturation point is reached. Through this curve, the coating thickness is accurately controlled to achieve the desired gloss effect. The green lacquer oil is quantitatively coated on the surface of the metal pattern by a precision coating machine. The coating machine can accurately control the coating amount and ensure the uniformity of the coating by adjusting the spraying amount and spraying speed of the spray head. In this process, the control system of the precision coating machine will control the required coating amount and dyne value within a reasonable range according to the preset coating amount curve, ensuring that the green lacquer oil coating is evenly distributed on the surface of the metal pattern. In order to ensure that the dyne value of the coating layer is within the preset range, the surface of the coating is dynamically monitored. Through the online detection system, the dyne value data of the coating surface is collected to determine in real time whether it is within the preset range. The dyne value of the preset range of 38 to 42 indicates that the coating has appropriate gloss and adhesion. The online detection system scans the coating layer in real time through a high-resolution gloss sensor and records the dyne value of each scanning point. Through these data, the online detection system can determine in real time whether the gloss of the coating is within the preset range and transmit the data to the control system for subsequent processing. According to the dyne value measurement data, the coating system needs to adjust the coating amount in real time. If the measured Diyne value is lower than the lower limit of the preset range, the system will automatically increase the coating amount; if the Diyne value is higher than the upper limit, the coating amount will be reduced. The coating amount is adjusted by controlling the spray volume and spray speed of the spray head. Through real-time adjustment, it can ensure that the Diyne value of the coating layer is always maintained within the preset range to ensure the quality and performance of the coating. By analyzing the Diyne value control data, the coating system will evaluate the surface treatment quality. Through the quality control system of the coater, a series of quality reports are generated based on real-time Diyne value data and coating amount to evaluate the uniformity and glossiness of the coating layer. The quality evaluation results will be displayed on the control panel, providing real-time feedback to production personnel to help adjust the coating parameters in time.

[0079] In one example, CMYK digital graphic data in a layered data file is imported into a digital printing device, and four-color ink dot printing is performed on the surface treatment layer to obtain an image graphic with a metallic texture, including:

[0080] The dot distribution information in the layered data file is imported into the digital printing equipment, and the dot coverage parameters of each CMYK ink are extracted through the digital analysis system to obtain the ink layering data;

[0081] The ink layering data is digitally processed, and the CMYK four-color ink overprinting dot size of each area is calculated through the ink supply system of the four-color printing unit to obtain the dot control parameters;

[0082] The print head parameters of the digital printing equipment are set according to the dot control parameters, and the ink jetting amount and dot size are set so that the ink does not completely cover the metallic texture of the treatment layer, and the printing control data is obtained;

[0083] The printing control data is input into the digital printing system, and the surface treatment layer is overprinted with four-color inks, and the reflection of the silver foil is transmitted through the combination of dots with different proportions to obtain the metallic color layer;

[0084] The image quality of the metal color layer is scanned and monitored, and the dot size and metal reflectivity of each area are collected by an image detector to obtain quality monitoring data. Based on the quality monitoring data, the printing parameters of the printing system are compensated and adjusted to make the metal effect and color effect of each area meet the set requirements, and obtain imaging images with a metallic texture.

[0085] In this example, the dot distribution information in the layered data file is imported into the digital printing device. These layered data include the coverage of different inks (CMYK) and the dot size of each ink. Through digital analysis, this information is converted into layered data of ink. The layered data contains the ink coverage required for each image area. These data are fine-tuned according to the color requirements of different areas, and the coverage parameters of the ink dots are extracted through the digital analysis system. The dot coverage parameter is an important indicator that describes the distribution of each ink in the image area, which determines the overprint density of the ink and the final printing effect. Assume that the dot ratio of each ink is , these proportions correspond to the ratio of the coverage area of ​​cyan, magenta, yellow and black inks to the total area. These inks are digitally processed by the ink supply system of the four-color printing unit. Through this process, the printing equipment calculates the size of the four-color ink overprinting dots in each area. The size of the dots directly affects the depth of color and the accuracy of printing. In the process of four-color ink overprinting, the superposition effect of the dots needs to be adjusted according to the different characteristics of the area. By calculating the dot size, the dot control parameters are obtained, which define the amount of ink that should be used in each area and the distribution pattern of the ink. Through calculation, the optimized dot distribution is generated to ensure that the color of the metal image has both layering and does not over-cover and destroy the metallic texture of the silver foil layer. According to the dot control parameters, the digital printing equipment needs to adjust the parameters of the print head, set the inkjet volume and dot size, so as to ensure that the ink does not completely cover the metallic texture of the treatment layer. The inkjet volume determines the amount of ink sprayed each time, while the dot size affects the distribution density of the ink, which in turn affects the depth and saturation of the color. In order to achieve accurate color overprinting while ensuring the metallic texture, the inkjet parameters of the print head are adjusted according to the dot control data. Through these formulas, the inkjet volume and dot size of the print head are dynamically adjusted to ensure that the ink spraying in each area can not only ensure the color restoration, but also not cover the silver foil layer with metallic texture. The printing control data is input into the digital printing system. The printing system performs color separation overprinting of four-color inks based on these data. The overprinting of four-color inks is achieved through the combination of dots of different colors. The size and distribution between the dots determine the transparency and color effect of the color. Especially in the display of metallic colors, the superposition of dots is very important. Through the combination of dots in different proportions, the system can control the overprinting effect of the ink, making the color level richer, and showing the gloss and texture of the metallic color by transmitting the reflection of the silver foil. For example, when printing a packaging design with metallic colors, the digital printing system uses different proportions of dot combinations to make the metallic color of some areas more vivid, while other areas show a softer color transition, achieving a color level with metallic texture. During the printing process, the silver foil layer controls the coverage of the dots and the amount of ink ejected to ensure the accurate presentation of the metal reflection effect. After printing is completed, the image detector scans and monitors the image quality of the metal color layer. The image detector collects the dot size and metal reflectivity in each area to generate quality monitoring data, reflecting the superposition effect of ink in the image area and the intensity of the silver foil reflective luster. The quality monitoring data includes the accuracy of the dots, the uniformity of printing, the color restoration, and the metal reflection effect. For example, through the analysis of the image scan, it is found that the dot density in some areas is insufficient, resulting in unclear metal luster, or the color of some areas is too dark, which requires compensation adjustment. According to the quality monitoring data, the printing system makes compensation adjustments to ensure that the metal effect and color effect of each area meet the set requirements.If the color effect of some areas is found to be poor, compensation can be made by adjusting the inkjet amount or dot size. Through real-time adjustment, it is ensured that the metal color effect and color level of each area meet the design requirements. Through a series of dot control, ink adjustment and quality compensation, digital printing equipment can accurately achieve the printing effect of metal color graphics.

[0086] Reference Figure 2 This embodiment provides a printing device for realizing metallic color on general coated paper based on digital printing, including:

[0087] The conversion module 1 is used to digitally partition the image and text area that needs to present a metallic texture, and convert the CMYK dot ratio parameters of the image and text area into vector data to obtain a layered data file;

[0088] The inkjet printing module 2 is used to perform UV adhesive oil inkjet printing on ordinary coated paper through the nozzle of the digital cold stamping equipment according to the layered data file to obtain a UV adhesive oil graphic layer;

[0089] The first irradiation module 3 is used to input the UV adhesive oil image layer into the UV light curing device for the first irradiation, so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured image area;

[0090] The second irradiation module 4 is used to apply silver foil to the pre-cured graphic area through a pressure roller system and irradiate it for the second time through a UV light source, so that the UV adhesive oil is completely cured and then the excess silver foil is separated through a separation roller to obtain a metal graphic pattern;

[0091] A coating module 5 is used to coat the metal pattern with blue lacquer oil through a coating machine, and control the surface dain value of the metal pattern to be within a preset range to obtain a surface treatment layer;

[0092] The printing module 6 is used to import the CMYK digital image data in the layered data file into the digital printing device, and perform four-color ink dot printing on the surface treatment layer to obtain an image with a metallic texture.

[0093] In this embodiment, for the specific implementation of each unit in the above device embodiment, please refer to the above method embodiment, which will not be repeated here.

[0094] Reference Figure 3 In an embodiment of the present invention, a computer device is also provided. The computer device may be a server, and its internal structure may be as follows: Figure 3As shown. The computer device includes a processor, a memory, a display screen, an input device, a network interface and a database connected through a system bus. Among them, the processor designed by the computer is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the corresponding data in this embodiment. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above method is implemented.

[0095] Those skilled in the art will understand that Figure 3 The structure shown in the figure is merely a block diagram of a portion of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied.

[0096] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the above method is implemented. It can be understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.

[0097] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided by the present invention and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double-speed data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM.

[0098] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0099] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for printing metallic colors on conventional coated paper based on digital printing, characterized in that: The following steps are involved: The method comprises the following steps: performing digital partitioning on the graphic area that needs to present a metallic texture, and converting the CMYK dot ratio parameters of the graphic area into vector data to obtain a layered data file; specifically comprising: performing regional recognition analysis on the graphic area that needs to present a metallic texture, and dividing the boundaries between the metallic texture area and the non-metallic texture area to obtain regional recognition data; performing data extraction on the metallic texture area according to the regional recognition data, setting the color space parameters of the metallic texture area to the CMYK mode, and obtaining CMYK color data; performing dot ratio calculation on the CMYK color data, and performing a CMYK color space calculation on the CMYK color data; performing a CMYK color space calculation on the CMYK color data; and performing a CMYK color space calculation on the CMYK color data. The dot coverage of four channels, cyan, magenta, yellow and black, is calculated to obtain dot ratio parameters; the dot ratio parameters are input into a vector conversion module, Bezier curve fitting is performed on the outline of the image and text, and anchor point coordinates are generated to obtain vector outline data; based on the vector outline data, an association mapping between a digital cold stamping silver foil layer and a printing layer is established to generate silver foil layer positioning data and printing layer dot data to obtain double-layer processing data; the double-layer processing data is data packaged according to a digital cold stamping process and a digital printing process to generate a layered data file containing silver foil positioning information and dot distribution information; According to the layered data file, UV adhesive oil is sprayed on ordinary coated paper through the nozzle of the digital cold stamping equipment to obtain a UV adhesive oil graphic layer; Inputting the UV adhesive oil pattern layer into a UV light curing device for a first irradiation, so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured pattern area; The pre-cured graphic area is subjected to silver foil lamination by a pressure roller system and irradiated for a second time by a UV light source, so that the UV adhesive oil is completely cured and then excess silver foil is separated by a separation roller to obtain a metal graphic pattern; Applying blue lacquer oil to the metal pattern by a coating machine, controlling the surface dain value of the metal pattern to be within a preset range, and obtaining a surface treatment layer; The CMYK digital graphic data in the layered data file is imported into a digital printing device, and the surface treatment layer is printed with four-color ink dots to obtain an imaged graphic with a metallic texture.

2. The method for printing metallic colors on universal coated paper based on digital printing according to claim 1, characterized in that: The method of performing UV adhesive oil spraying on ordinary coated paper through a nozzle of a digital cold stamping device according to the layered data file to obtain a UV adhesive oil graphic layer includes: Inputting the silver foil layer positioning data in the layered data file into the control system of the digital cold stamping device to generate printing path data that completely matches the boundary of the graphic area; Performing coordinate transformation on the printing path data, calculating the absolute position coordinates of the nozzle according to the position compensation parameters of the common coated paper, and obtaining the compensated positioning data; According to the compensated positioning data, the UV adhesive oil injection parameters of the digital cold stamping machine nozzle are adjusted, and the injection amount and injection timing of the UV adhesive oil are controlled by the pulse control signal to obtain the injection control signal; The spray control signal is input into the execution unit of the digital cold stamping equipment, and the UV adhesive oil is quantitatively sprayed at the designated position of the ordinary coated paper to form a UV adhesive oil coating layer that completely corresponds to the image area, thereby obtaining an initial UV adhesive oil layer; Performing boundary scanning on the outline of the initial UV adhesive oil layer, collecting position information and thickness data of the edge of the layer, and obtaining layer detection data; The contour accuracy and coating uniformity of the initial UV adhesive oil layer are evaluated according to the layer detection data, and the uneven area is corrected and re-sprayed through a digital calibration algorithm to obtain a UV adhesive oil graphic layer.

3. The method for printing metallic colors on conventional coated paper based on digital printing according to claim 2, characterized in that: The step of inputting the UV adhesive oil pattern layer into a UV light curing device for first irradiation so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured pattern area comprises: The UV adhesive oil pattern layer is transported to a UV light curing device, and the feeding position of the UV adhesive oil pattern layer is positioned by a sensor system to obtain UV adhesive oil positioning data; The UV adhesive oil positioning data is analyzed, and the curing degree is set to a range of 60%-80% according to the UV light source irradiation parameters to obtain a UV light source irradiation plan; Inputting the UV light source irradiation scheme into the control unit of the UV light curing device, starting the UV light source to irradiate the UV adhesive oil image layer for the first time, and obtaining an initial cured layer; Performing a curing state detection on the initial cured layer, collecting surface state parameters of the cured area through an optical imaging system, and obtaining curing state data; Calculating the curing degree of the UV adhesive oil according to the curing state data, and performing UV light intensity compensation by comparing the set curing range to obtain curing compensation data; The curing compensation data is corrected, and the UV adhesive oil reaches the target state of the first curing through the supplementary irradiation of the UV light source, thereby obtaining a pre-cured graphic area.

4. The method for printing metallic colors on universal coated paper based on digital printing according to claim 3, characterized in that: The pre-cured graphic area is subjected to silver foil lamination by a pressure roller system and irradiated for a second time by a UV light source, so that the UV adhesive oil is completely cured and then excess silver foil is separated by a separation roller to obtain a metal graphic pattern, including: The pre-cured graphic area is transmitted and positioned, and data of the pre-cured graphic area and the position of the transferred silver foil are collected by multiple sets of sensors to obtain position matching data; The pressure parameters of the pressure roller system are set based on the position matching data, and the pressure distribution parameters are synchronized to the pressure roller driving device through the digital control system to obtain pressure control data; According to the pressure control data, the pressure roller system is driven to operate so that the transfer silver foil is fully laminated with the pre-cured graphic area to obtain a silver foil pre-laminated layer; The silver foil pre-lamination layer is irradiated with a UV light source for a second time, and the UV adhesive oil is completely cured to 100% by a UV light source control system to obtain a cured lamination layer; The tension of the cured bonding layer is controlled by a separation roller system, and the excess transfer silver foil film is peeled off at a fixed angle and speed to obtain a silver foil image layer. The surface of the silver foil image layer is quality inspected, and the integrity of the silver foil attachment area is analyzed and evaluated by image scanning to obtain a metal image pattern.

5. The method for printing metallic colors on conventional coated paper based on digital printing according to claim 4, characterized in that: The method of coating the metal pattern with blue lacquer oil by a coating machine and controlling the surface dyne value of the metal pattern to be within a preset range to obtain a surface treatment layer comprises: Scanning the surface state of the metal graphic pattern, detecting the metal glossiness of the silver foil attachment area by a surface analyzer, and obtaining surface characteristic data; The coating thickness of the green lacquer oil is calculated according to the surface characteristic data, a corresponding relationship curve between the coating amount and the dyne value is generated, and the green lacquer oil is quantitatively coated on the surface of the metal pattern by a precision coating machine to control the uniformity of the coating layer to obtain a green lacquer oil coating; Dynamically monitor the surface Diyan value of the green lacquer oil coating, collect Diyan value data of the coating surface through an online detection system, determine whether it is within a preset range, and obtain Diyan value measurement data, wherein the preset range is 38-42; The coating amount of the coating system is adjusted in real time according to the Dyne value measurement data to ensure that the Dyne value of the coating layer is maintained within the preset range, and the Dyne value control data is obtained. The Dyne value control data is analyzed, and the surface treatment quality is evaluated through the quality control system of the coater to obtain the surface treatment layer.

6. The method for printing metallic colors on conventional coated paper based on digital printing according to claim 5, characterized in that: The method of importing the CMYK digital graphic data in the layered data file into a digital printing device and performing four-color ink dot printing on the surface treatment layer to obtain an image with a metallic texture includes: The dot distribution information in the layered data file is imported into a digital printing device, and the dot coverage parameters of each CMYK ink are extracted through a digital analysis system to obtain ink layering data; The ink layering data is digitally processed, and the CMYK four-color ink overprinting dot size of each area is calculated through the ink supply system of the four-color printing unit to obtain the dot control parameter; Setting print head parameters of a digital printing device according to the dot control parameters, setting the inkjet amount and dot size so that the ink does not completely cover the metallic texture of the treatment layer, and obtaining printing control data; The printing control data is input into a digital printing system, four-color ink separation and overprinting is performed on the surface treatment layer, and the reflection of the silver foil is transmitted through the combination of dots with different proportions to obtain a metallic color layer; The image quality of the metallic color layer is scanned and monitored, and the dot size and metallic reflectivity of each area are collected by an image detector to obtain quality monitoring data. Based on the quality monitoring data, the printing parameters of the printing system are compensated and adjusted to make the metallic effect and color effect of each area meet the set requirements, thereby obtaining an image with a metallic texture.

7. A printing device for achieving metallic colors on conventional coated paper based on digital printing, characterized in that: For implementing the steps of the method according to any one of claims 1 to 6, the device comprises: A conversion module, used for digitally partitioning the image and text area that needs to present a metallic texture, and converting the CMYK dot ratio parameters of the image and text area into vector data to obtain a layered data file; A printing module, used for printing UV adhesive oil on ordinary coated paper through a nozzle of a digital cold stamping device according to the layered data file to obtain a UV adhesive oil graphic layer; A first irradiation module is used to input the UV adhesive oil image layer into a UV light curing device for a first irradiation, so that the UV adhesive oil is cured to a preset curing degree to obtain a pre-cured image area; The second irradiation module is used to apply silver foil to the pre-cured graphic area through a pressure roller system and irradiate it for a second time through a UV light source, so that the UV adhesive oil is completely cured and then the excess silver foil is separated through a separation roller to obtain a metal graphic pattern; A coating module, used for coating the metal pattern with blue lacquer oil through a coating machine, controlling the surface dain value of the metal pattern to be within a preset range, and obtaining a surface treatment layer; The printing module is used to import the CMYK digital image data in the layered data file into a digital printing device, and perform four-color ink dot printing on the surface treatment layer to obtain an imaged image with a metallic texture.

8. A computer device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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