平版胶印中墨层厚度与复频谱饱和度的关系

Relationship between Ink Thickness and Complex Frequency Spectrum Saturation in Offset Printing

在平版胶印过程中,墨斗的供墨量直接影响墨层厚度,进而影响印张颜色效果。由于人眼难以判断墨层的厚度,本研究通过检测印张颜色的饱和度来调控墨层的厚度:应用复频谱光谱仪测出油墨墨层厚度与颜色饱和度的相关数据,绘出复频谱饱和度与CIE饱和度曲线图。由于两者饱和度定义不同,致使其对墨层厚度变化响应的灵敏度不同。两组数据表明,复频谱饱和度反差△S_1比CIE饱和度反差△S_2大;中黄、洋红、天蓝三种油墨颜色性能虽然不同,但在墨层厚度与饱和度的关系方面有一致性,表现为三种油墨在墨层厚度为4μm左右时存在一个拐点,拐点以后,即使墨层厚度继续增加,饱和度将不再发生明显变化。

In the offset printing process,the amount of ink supplying of fountain directly affects ink thickness,thereby affecting the color quality on the printing sheet.Ink layer thickness is difficult to judge by human eyes,but the ink thickness can be regulated by detecting the color saturation.In this paper,measured data ink layer thickness and color saturation was described using complex spectrum spectrometer and two graphs of complex spectrum saturation and CIE saturation were made.Due to the different definitions of saturation,the sensitivities of layer thickness changes response are different.Two sets of data showed that the complex spectrum saturation contrast AS,significantly was higher than CIE saturation contrast △S_2.The ink color performance in terms of the relationship between layer thickness and saturation had an inflection point when the ink film thickness is about 4 μm,After reaching inflection point,even if the ink layer thickness continues to increase,there would be no significant changes in the saturation.