Study On The Technologic Parameters Of Ink-Jet Printing

The digital printing has been paid more and more attention, for its traits of short cycle, individuation and long-distance printing. The purpose of this thesis is to study on the digital ink-jet printing technologic parameters, and to obtain the scheme for output parameters choice and quality control. The conclusion can be used for the criterion of ink-jet printing technology, improving production efficiency and economy benefit for the enterprises, promoting the development and popularization of digital printing technology, and providing the theory and practice basis for the digital printing standardization.The study methods: Based on digital printing and offset printing technology principle, the basic parameters having effect on the ink-jet printing output quality were analyzed. And the mathematics models between the ink quantity and the solid density, and the relation between the gamma and printing contrast (K) were established. The relation among the output dot area coverage, the original dot area coverage and the dot-gain percent was analyzed. And the mathematics models of printing characteristics curves and dot-gain curves were established. The factors influencing the dot-gain were analyzed, and then the dot-gain compensation function was acquired. All the models were verified by the method of regression analysis. And the precisions of the models were obtained by the correlation coefficient and multiple correlation coefficients. The gray balance curves were obtained by the gray balance function and regression analysis.The main works: The parameters in the mathematic models were ascertained, as well as all the regression functions. The models included the relation between the ink quantity and the solid density, the relation between the gamma and printing contrast, the printing reproduction curves, the dot-gain curves and the dot-gain compensation curves. The fitting accuracies of the regression models were checked out by the correlation coefficient or multiple correlation coefficients. The effect that the ink had on the solid density and the gamma on the printing contrast were analyzed. And the methods of choosing the ink and gamma were gained. The regular functions of gray balance, dot-gain and dot-gain compensation were also obtained for the ink-jet printing quality control.The main conclusions: The solid density of the C,M,Y,Bk were best when the ink quantity were 85,100,100,100 in the digital ink-jet printing. The gamma affected on the middle part of the printing characteristics curves, the bigger gamma, the more compression for the middle part. The relation curves between gamma and the K were fit in with Pearl curves. The END curves of the gray balance between the monochromatic density and the dot area coverage are obtained for the digital printing gray balance. The relation curves between dot-gain percent and the original dot area coverage of C,M,Y,Bk were parabolas. And the dot-gain was larger in the 50% original dot area than the others.