Color screen printing has the advantages that other printing methods do not have, which occupies a considerable proportion in the application of various types of outdoor advertising, and has the advantages of large batch reproduction and low cost.Next, let's understand the specific process of color screen printing.
(1) The key of color silk printing lies in the plate making of color continuous adjustment image.
In the plate making process, the following problems should be considered: the amplification of the image must consider the proportion relationship of the network plate.Normally, the original version is the positive image, but if it is printed in the transparent material exhibition, the original version should be the positive image.The network cable Angle of yellow, magenta, green, black soft pieces should not only avoid the occurrence of turtle lines, but also consider the influence of the longitude and longitude gate of the screen on color reproduction.
(2) Color screen printing materials selection and process should pay attention to:
four frames should be metal frame, and the specifications should be completely the same.
It should be used with high precision, anti-halo staining screen, and the number of items is determined according to the magnification of the printed pattern.
When bandaged, the four plates shall be made on the same equipment or under the same conditions.The method of "one network stretched four" should be adopted to ensure the consistent tension and accuracy of the four network frames.A stretched net, should be placed 1~2 days before use, to ensure that it is sufficient "relaxation".Using direct method to make template, the coating thickness of photoglue should be uniform.When keeping the pumping, light source, exposure time and development are controlled in the same ladder (using the accompanying ladder ruler).The template shall be kept and used under the specified conditions.Large or precision screen printing machine for printing, with the temperature control of 18℃ to 25℃ and humidity control range of 50% to 70%.The printing net distance should be as small as possible to improve the overprinting accuracy and reduce the phenomenon of turtle lines.The length of the sweet ink knife should be the same, with less pressure.The ink blade Angle is about 75 ~80, the hardness is slightly larger, namely xiao's hardness is about 70, the blade should be kept sharp.
The uniform ink shall be thin (about 20 m) and well-distributed to prevent the ink from filling the mesh.
The choice of ink must be matched with the undertaking material, and the spectral characteristics of the three primary color ink are better, higher transparency, viscosity can be slightly larger, so that the network stands up, to avoid expansion.Should use on the printing plate of slow dry, imprinted fast dry ink.Various bearing materials must be treated with the suitability of the material before printing.Printing color order generally adopts the first printing deeper non-main color, after the main color, so as to facilitate overprinting from: if the printing color order on the transparent plastic material should be reversed, and need to add the background color first, and then according to the color order.
