Abstract

A layered printing plate that attains a high degree of clarity and improved clean out. The printing plate may include an oleophilic substrate, a laser absorbing imaging layer and an oleophobic silicon layer. One embodiment utilizes an amine resin rather than a traditional polymer as the basic organic matter of the imaging layer, adds of colloidal silica into the imaging layer to improve the cleanout properties, and utilizes a substrate that absorbs IR radiation rather than reflects it.

IPC Classes  ?

• B41N 1/00 - Printing plates or foilsMaterials therefor
• B41C 1/10 - Forme preparation for lithographic printingMaster sheets for transferring a lithographic image to the forme

Abstract

Wet lithographic printing members for imaging by an inkjet printer using pigment-based aqueous ink and method for calibrating the amount of the inkjet ink to be injected in solid areas of an image are disclosed. An exemplary printing member can comprises a base substrate and a top hydrophilic coating layer having a thickness in the range of 2 to 10 microns above the base substrate. A volume of less than 10 nl/mm2 of inkjet ink is used in order to image areas in which the image is solid. Areas of the top hydrophilic coating layer, which are imagewise covered by aqueous pigmented inkjet ink, become hydrophobic. In some embodiments after imaging, the surface of the imaged printing member can be treated with acidic colloidal silica solution. Exemplary treatment can comprise wiping the surface of the imaged printing member with the acidic colloidal silica solution.

IPC Classes  ?

• B41F 1/18 - Platen presses, i.e. presses in which printing is effected by at least one essentially-flat pressure-applying member co-operating with a flat type-bed for lithography