弹流润滑下的胶印机油墨墨层分析

Elastohydrodynamic Lubrication Analysis of Ink Layer in Offset Printing

为了了解油墨在传递过程中的特性,应用弹性流体动力润滑理论对印刷油墨在一软一硬两墨辊间接触区内的最大压力及油墨墨层厚度进行了分析.应用实验的方法确定了国产某品牌黄色印刷油墨的黏压系数,通过弹流润滑基本方程的建立及相关参数的确定,分析了载荷、速度、材料的改变对接触区内油墨压力及墨层厚度所带来的影响.分析表明:载荷增大时墨层压力随之增加,墨层厚度逐渐减小,墨层厚度随载荷增大而减小的幅度逐渐减小,并逐渐趋于一种稳定的状态;两辊对滚速度增大时油墨墨层压力几乎无变化,墨层厚度随之增大;硬辊弹性模量的变化,对接触区内油墨压力及油墨层厚度的影响不大;软辊弹性模量增大时最大墨层压力随之增大,但墨层厚度变化不明显.

To analyze the features of printing ink in the transfer process,the elastohydrodynamic lubrication theory was used to analyze the m a x i m u m pressure and the thickness of the ink in the contact area between a soft ink roller and a hard one.This paper ascertained the viscosity-pressure coefficient of a yellow printing ink by experiment and analyzed the influences of the load,speed and the materials on the pressure and the thickness of the ink in the contact area.Analysis shows that with the increase of the load,the ink pressure increases,the thickness of the ink decreases,and the thickness of the ink tends to be a stable state.W h e n the speed increases,the ink pressure almost does not change,and the ink thickness increases.The change of elastic modulus of the hard roll has slight effect on the ink pressure and the thickness of ink,and the pressure increases with the increase of the elastic modulus in soft roll;however,the change of thickness is not obvious.