基于实验数据和过滤方程的胶印油墨固着速度改进预测

在印刷工艺中,涂布纸对油墨油的吸收是非常重要的,其决定了油墨的固着速度,从而影响印刷质量及生产能力。在过去的15年里,许多科研人员研究了涂层的孔状结构对油墨固着的影响,但并没有关于油墨组分及乳化对油墨吸收及固着影响的报道。研究人员曾提出过几种不同的假设来描述油墨油的吸收过程。Donigian提出了多相理论来描述油墨油的吸收,假设涂层结构对树脂相及油墨油相的吸收速率不同;Gane等人提出,油墨的逐渐固化表明涂层吸收油墨油的过程是在没有任何明显组分分层下逐渐固化的;Xiang和Bousfield提出的滤饼理论表明,颜料粒子与累积在墨层与涂料之间的的硬树脂也具有滤饼特征。在印刷过程中加入润版液会改变油墨的黏度。Ercan指出在高和低剪切率下,黏度与印刷中油墨拉丝有一定的相关性。尤其是与稀释剂（如矿物油）的纯黏性行为相比,油墨（包括相互溶解的软树脂）的弹性增加时会导致更小的拉丝。Xiang在更早的时候已提出这种假设。Xiang后期的工作表明纯油墨与油墨乳化后形成的墨膜初始状态存在差异。Xiang和Fr（o｜¨）berg研究了乳化油墨的黏性,他们发现油墨附着过程中黏性上升的初始速率似乎不受外加因素的影响。本文主要研究油墨油组分和油墨乳化现象对固着速度的影响,并将基于滤饼理论的预测与实验结果进行比较,以过滤实验和流变测试的结果拟合描述油墨固着过程方程,并探讨在不同纸张上,3种油墨（热固型油墨、乳化热固型油墨、单张纸胶印墨）固着速度的差异。

Improved Prediction of Offset Ink Setting Rates Based on Experimental Data and Filtration Equations

The setting rates of inks on paper influence the printing operation and the quality of the final product.Although much work has been reported on the effect of the coating structure on setting rates,much less work has been done understanding the ink parameters,especially the influence of emulsification.A series of four papers were tested with three inks. The inks were characterized in terms of printing properties,rheology,and their filtration behavior.The filtration rate is used to obtain a permeability value of the ink filtercake.The value of the maximum tack was determined to be more dependent on the smoothness of the paper tested than on the type of ink.The dynamics and magnitude of the tack test were dependent on the ink viscosity,but viscosity alone does not explain the results.The measured ink filtercake permeabilities are different between the ink types by a factor of 2.The setting rate is found to be primarily a function of the viscosity of the oil used in the ink,rather than a function of the pigment and resin system.