Printing press with mechanical development of imaged plate

Abstract

On-press development of an imaged printing plate on a plate cylinder, in which ink is applied by an ink form roll, a blanket roll is in contact with the plate, a rubber roll is opposed to the blanket roll, and printable media passes between the blanket roll and the rubber roll. The plate comprises a substrate carrying an imaged coating, in which nonimage areas have cohesion C1, adhesion to the substrate A1, and adhesion to the applied ink A3 and image areas have cohesion C2, adhesion to the substrate A2, and adhesion to the applied ink A4. The ink has cohesion C3 and adhesion A5 to the blanket roll. The nonimage areas have adhesion A6 to the printable medium and the ink has adhesion A7 to the medium. The adhesions and cohesions are such that the blanket roll pulls the ink from the plate and the ink pulls the nonimage areas from the substrate as undissolved particles that are transferred by the blanket with the ink to the printable media.

Description

RELATED APPLICATIONS[0001]This is a divisional of U.S. application Ser. No. 12 / 799,568 filed Apr. 27, 2010 for “Processless Development of Printing Plate”, which is a continuation-in-part of U.S. application Ser. No. 12 / 586,764 filed Sep. 28, 2009 for “Non-Chemical Development of Printing Plates”, which is a continuation-in-part of U.S. application Ser. No. 11 / 493,183 filed Jul. 26, 2006 for “Imagable Printing Plate for On-Press Development”, which claims priority under 35 U.S.C. §119(e) from U.S. Provisional Application No. 60 / 704,140 filed Jul. 29, 2005, for “Imagable Printing Plate for On-Press Development”, and benefit under 35 U.S.C. §120 is also claimed from U.S. application Ser. No. 11 / 821,721 filed Jun. 25, 2007 for “Water Spray Development of Planographic Plates” and U.S. application Ser. No. 12 / 215,124 filed Jun. 25, 2008 for “Heated Water Spray Processor”. The complete disclosures of these applications are hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]...

AI Technical Summary

Benefits of technology

"The invention is about a process for making a lithographic plate by using a special coating that is applied to a hydrophilic substrate and then exposed to polymerizing radiation. The coating is made up of active components that are insoluble in water and has a negative working mechanism. The unimaged areas of the coating are then removed by mechanical force, leaving behind a patterned surface that can be used for printing. The process does not require any separate developing equipment and is efficient and cost-effective."

Problems solved by technology

Not only is a high level of energy required for imaging such plates, but the rate of imaging is slow and the resolution is low.

Images