subject: Color Multicolor Overprint Of The Law - Color Printing, Overprint - Printing Industry [print this page] Print Process is a very complicated processPrint Process is a very complicated process. In the process, accompanied by the transfer of ink, all kinds of problems often occur. These problems and print quality are closely related to good or bad. In multicolor printing, the colored ink overprint if not properly controlled, will cause a change in the color printing, resulting in print quality problems. Therefore, we must overprint ink analysis and study of the situation.
In the actual printing production, trapping poor printing defects caused the greatest scab in crude. According to experience, lead to multi-color printing color images of the main reasons overprinting scab in crude ink viscosity, print pressure, print speed, the surface strength of paper, printing interval of time, poor control of any of these factors will influence the final color print printing quality, can easily cause scab in crude failure. This article is from the impact of trapping of these factors, the multi-color printing on the color overlays to study and explore the law. To achieve the above purpose, this article focuses on changing the ink from the viscosity, print pressure and print speed of the factors affecting trapping trapping experiments, and analyze experimental results and trapping scab in crude relationship between the print scab in crude also analyze other factors, such as paper surface properties , trapping time interval, the printing color sequence and so the conclusion that multi-color overprint color printing in the law.
One on the trapping of ink viscosity
1. Ink viscosity On wet trapping has a great influence, ink viscosity, ink showed a greater cohesion, if after the first printing ink printing ink viscosity than the viscosity is low, after the printing ink will be dependent on the cohesion of its own, the first India ink stick away, have a "reverse trapping" caused by mixing. So, good viscosity control are critical.
2. Ink viscosity effect on the trapping experiment
Laboratory equipment: Long Sound Industrial Co., Ltd. Production of S-1000 four-color water Printing slotting machine , 4 # cup viscosity test
Experimental steps: overprint in blue on black, blue ink viscosity 11.3s, black ink viscosity of 13s, the initial printing speed of 40 turn / min, the printing pressure of 3.6mm, the substrate was used White tissue paper jam B- Corrugated paper In this print the initial scab in crude under 10%.
change the viscosity of black ink, other initial conditions remain unchanged for printing, observed scab in crude, and to record data.
experimental data through tables, mapping out the relationship between ink viscosity and trapping curve.
Second, the impact of printing pressure on the trapping
1. Printing pressure Printing process, in a sense, is to solve the contradiction between the ink and paper process. Graphic printing plate to ink transferred to the Office of the substrates, they must exert a certain force, the so-called printing pressure. It has an important role in the printing.
Printing pressure control is not easy. Printing pressure is too large or too small, will result in lower printing quality. In particular, excessive pressure caused by the shortcomings of more, it often causes graphic distortion, local accumulation of ink, paper galling, imprinting of the network expansion, and poorly printed materials and other failures. On the contrary, the printing pressure over an hour, can cause incomplete transfer of printing graphics, dot false, and many more obvious flaws exposed fault. Therefore, in the printing process, the printing pressure control in the context of more appropriate it is very crucial.
2. Printing pressure on the trapping of experiments
Laboratory equipment: Long Sound Industrial Co., Ltd. Production of S-1000 water-based four-color printing Slot Machine
Experimental steps: overprint in blue on black, blue ink viscosity 11.3s, black ink viscosity of 13s, the initial printing speed of 40 turn / min, the printing pressure of 3.6mm, the substrate was used White tissue paper jam B- Corrugated Paper, printing conditions, this initial scab in crude was 10%.
