Research On The Spreading Effect Of Ink For Ink-jet Printing

Commercial glossy, matte papers and inks (pigment and dye inks) are studied in this paper. CMYK pure ink dots are collected by digital image acquisition device and CMYK sigle ink dot is extracted by image processing software. According to the geometry of ink dots on paper, a mathematical model which called the spreading effect of ink and paper for ink-jet printing is established. It consists of two parts; one is that by the reconstruction of dots and distance space, the difference value of actual and ideal dots can be calculated; another one is that the edge spreading is expressed by the relationship between perimeter and area of ink dots. Then, a model parameter, IJS (Ink Jet Spreading), is definited, we can assess the spreading degree of ink dots, analyze the paper performances and verify by subjective evaluation.The results of spreading effect of ink on paper show that the absorbent and color reductive of glossy samples are better for pigment-based inks, and the spreading degree of ink dots are lower. The interaction between Epson sample and color inks is the best; the absorbent of Kodak sample is the worst for pigment-based inks; Diamond sample is hard to absorb dye-based inks. It is also shown that the absorbent and color expression of matte samples are better for pigment-based inks. The absorbent of Qisen sample is the best for pigment-based inks; Tianwei sample absorbs dye-based inks more uniformly; the interaction between Liangcai sample and color inks is the worst. The spreading degree of glossy samples is much lower than matte samples.The results of the relationship between paper performance and ink spreading effect shows that the spreading of pigment-based inks on glossy papers are depended by the performances of glossy samples, and their paper roughness, whiteness and gloss effect the interaction of dye-based inks and papers. The spreading of pigment-based inks on matte papers is depended by the roughness and whiteness; the paper roughness affects the absorbent of matte papers.According to the subjective evaluation, it’s shown that the IJS values which express the spreading degree are consistent with the results of paired comparison. Therefore, the accuracy of the mathematical model is better, and it can offer theoretical foundation for the improvements of inks and papers.