To structure the surface of a printing plate, for offset printing, the hydrophilic polymer layer is heated locally to melt and form hydrophobic zones without material removal

摘要

To structure the surface (4) of a printing plate (2), with a hydrophilic polymer (6), to form hydrophilic and hydrophobic zones, energy is applied as a laser beam to at least one zone (8) of the plate surface where the polymer is hydrophilic. The plate material melts and is mixed (10) through so that it is hydrophobic when set.