Metal sign printing color difference control method

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Metal sign printing color difference control method

A printed signage product made of sheet metal, sheet, metal foil and other materials as a substrate is called metal sign printing. In the process of metal sign printing, there are often cases where the color difference of the printed matter is encountered. The following is a brief introduction to the control method for the color difference in the metal printing sign process:

In the process of metal sign printing, the color difference of the printed products mainly includes: ink solid color difference, color difference, color difference, dot color difference, color difference caused by improper printing, color difference caused by abnormal wet system, color label printing and glazing production process. The color difference that appears, etc.

I. Ink solid color difference: such as primary color or spot color ink, the main reasons for the actual color difference are: 1 color phase matching is not accurate, the type of ink used and the proportion of the ratio is unreasonable, can not meet the printing requirements; 2 ink printing properties and Printing machine, drying room performance is not suitable; 3 ink hue and ink layer thickness is not suitable or the amount of ink.

Control method: 1 collect data in the actual printing process of metal sign, clarify the relationship between the thickness of ink layer and the density of the ground, and control the amount of ink during printing; 2 the printing suitability of ink should meet the objective conditions of printing, the viscosity of ink The liquidity should be adjusted according to the nature of the substrate, the speed of the machine, the type of graphic, and so on. The speed of the machine is fast and the printing on the ground requires that the viscosity of the ink is relatively small, and the fluidity is relatively large, and vice versa. 3 When the ink is first formulated, the printing standard should be used as a standard. If necessary, the ink hue standard database should be established for later deployment. Standard basis.

2. Color difference of color mixture: including network cable and solid bottom, the main reasons for color difference are: 1 color sequence is unreasonable; 2 ink viscosity is unstable; 3 ink imbalance, ink tube, water bucket adjustment is unreasonable, operation is wrong .

Control method: 1 control the thickness of the ink layer, the viscosity of the ink; 2 arrange the metal label printing sequence reasonably: the general sub-tone first print, the main color after the print. The color with low coverage of the dot is printed first, the color with high dot coverage is printed, the textured version is printed first, and the real version is printed. The ink with high viscosity is printed first, the dark color is printed first, and the light color is printed. The first print with a small area of ​​graphic and text, the large print of the image area. The darkness of the first print, the high mark of the post. In fact, the color sequence adjustment should be carried out according to different contents and characteristics; 3 adjust the ink fountain and water bucket to control the ink and water balance.

3. Deformation color difference of the dot: The cause of the deformation of the dot is mainly caused by: 1 the increase or decrease of the mechanical dot, including the influence of printing pressure, ink, dampening solution, blanket, metal plate surface coating, etc.; 2 optical dot increase Or reduction, refers to the change in dot appearance of the metal sign printed negative film during the transfer to the PS plate.

Control method: 1 Adjust the pressure to meet the printing requirements. If the pressure is too large, the metal sign printing plate will appear image expansion, and the dot imprinting level will be unclear and cause the plate to be lost, which will affect the printing durability. The pressure is too small, the printing plate has poor ink, the print definition is poor, the dot is empty; 2 control the viscosity of the ink; 3 control the pH value and conductivity of the dampening solution; 4 the blanket installation meets the standard to prevent the blanket from stretching, The change of the dot caused by the twisting or compression deformation; 5 precisely control the exposure time to ensure the reduction of the film.

4. The color difference caused by inaccurate overprinting is mainly caused by the inaccurate positioning of the color plates during the overprinting process. Control method: 1 pressure adjustment meets the requirements of metal label printing, including various pads; 2 front gauge, side gauge, accurate positioning of the jaws; 3 installation PS version conforms to the procedure; 4 print size restores the film size; Accurate positioning; 6 metal signage production dimensional accuracy in line with national standards, in line with equipment performance.