Direct inkjet imaging lithographic plates, methods for imaging and pre-press treatment

摘要

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.

主权项

1. A method of printing, the method comprising the steps of:
providing a printing member comprising a base and a hydrophilic polymer coating thereover, the hydrophilic coating including inorganic particles therein; imagewise applying an aqueous inkjet ink to the surface of the member with an areawise application level less than 10 nl/mm2; and printing with the printing member in a wet offset process by repeatedly (a) dampening the printing member, (b) applying ink to the dampened printing member, (c) imagewise transferring the ink to a blanket to form an image thereon, and (d) transferring the image to a recording medium to form a printed image.