Waterless offset printing process principle

Waterless offset printing plates are available in both positive and negative formats. Currently, the positive type waterless offset printing plate is used more often.

Taking a positive-type waterless offset printing plate as an example, it is composed of an aluminum plate base layer, a bottom layer, a photosensitive resin layer, a silicone layer, and a cover film. After the exposure, the silica gel layer of the light part (blank portion) on the printing plate undergoes a bridging reaction to perform photocrosslinking; and the silicone layer without the light part (image part) is removed under the action of the developer to expose The photosensitive resin layer below. Since the photosensitive resin layer is ink-receptive, and the non-graphical portion of the silicone layer repels ink, the need for fountain solution intervention eliminates the need for selective ink adsorption.