DAMPING WATER-FEED ROLLER FOR OFFSET PRINTER

摘要

PROBLEM TO BE SOLVED: To eliminate the necessity of addition of alcohol or the like for the purpose of lowering the surface tension of damping water and improve the resistance to corrosion and resistance to wear by forming an oxide glass film on the outer peripheral face of a metal roller support and specifying the surface roughness of the film. SOLUTION: A continuous water supply device of an offset printer is provided with a water fountain roller 4 rotated by immersing its lower section in the water in a water tank 5, a damping water roller 3 rotated being in contact with the water fountain roller 4 and a water immersion roller 2 rotated being in contact with the damping water roller 3, and water adhered to the surface of the water immersion roller 2 is fed to a non-immersion section of a plate cylinder 1. In that case, the damping water roller 3 is provided with a metal roller support constituted of cast iron or the like and an oxide clay film formed on the outer peripheral face of the metal roller support and the surface roughness of the oxide glass film is set as 1.0μm or less. As the oxide glass film, it is suitable to use a glass tube or an enameled glass.