Abstract
Five types of test blankets were prepared to study the effects of surface roughness and compressibility on ink transfer. Three types of these blankets had different surface roughness, while two types had different compressibility on the identical surface compound and surface roughness. There are many white micro spots in solid area printed by smoother surfaced blanket, as the ink layer, which contain micro drops of fountain solution transfer from PS plate to blanket without deforming. The rougher surfaced blanket tend to be a little white micro spots in solid area, since the ink layer is forced to move to all holizontal direction along micro concave of the blanket at the printing nip. The fine pattern image, printed by a blanket with smoother surface deforms the ink layer move than that with rougher surface. It is thought that the rough surfaced blanket has more micro convex and concave, which disturb the spread of ink layer at the printing nip. Concerning the compressibility of blankets, high modulus blanket has less white micro spots than low modulus blanket, probably of the printing pressure moving the ink layer to holizontal direction.
