Direct thickness measurement of doctor-bladed liquid film on gravure roll surface
Direct thickness measurement of doctor-bladed liquid film on gravure roll surface
复制标题
凹版辊表面刮刀液膜的直接厚度测量
DOI：
10.1007/s11998-015-9714-z
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发表时间：
2015
影响因子：
2.3
通讯作者：
M. Yamamura
中科院分区：
文献类型：
--
作者：
Hidenobu Miura;M. Yamamura
我们提供的实验证据表明，保留在刮刀凹版辊表面上的液膜显着影响液体从雕刻辊表面到移动基材的转移。在不同的辊速和刀片厚度下，直接测量三螺旋凹槽和平台（凹槽之间的无凹槽区域）上的刮刀液膜的局部自由表面轮廓。液膜在低于临界毛细管数的区域上以有限的厚度覆盖辊表面。毛细管数量的增加导致从完全填充配置到饥饿配置的转变，其中液体几乎保留在平台上并部分填充具有凹形表面轮廓的凹槽。随着凹版辊表面液体厚度的减小，液体转移率单调降低，对于不同的刮刀厚度遵循单一曲线。此外，液体厚度的减小促进了流动不稳定性从不稳定滴流过渡到具有均匀表面的稳定状态到级联。
We provide experimental evidence that the liquid film remaining on a doctor-bladed gravure roll surface significantly influences the liquid transfer from the engraved roll surface to a moving substrate. The local free surface profiles of doctor-bladed liquid films were directly measured on both tri-helical grooves and lands (the nongrooved areas between grooves) at different roll speeds and blade thicknesses. The liquid film covered the roll surface with a finite thickness on the lands below the critical capillary number. An increase in the capillary number led to a transition from a fully filled to a starved configuration, in which the liquid barely remained on the lands and partly filled the grooves with a concave surface profile. The liquid transfer ratio monotonically decreased with a decrease in the liquid thickness on the gravure roll surface, obeying a single curve for different blade thicknesses. Furthermore, the decrease in liquid thickness promoted a flow instability transition from unstable dripping though a stable state with a uniform surface to a cascade.