Abstract
To understand main ink transfer mechanisms in mimeographing, the theoryof poroelasticity is applied to analyze the ink flow through screens and a printingmaster which are modeled by a fluid-filled poroelastic single layer. Thelayer is assumed to be pressed by a press roller from below and to be subjectedfrom above to the hydrodynamic lubrication pressure induced between a printingdrum and an ink roller. The deformation of the layer and the accompanyingink flow are shown to be governed by four nondimensional parametersnewly defined here. The numerical results show some important results; e.g., squeezing-out of the ink from the layer by the layer compaction by the pressroller plays an important role among various possible ink transfer mechanisms, especially for the case where the compression duration is small in comparisonwith the characteristic time of the layer.
