Presstek, Inc.

Kenneth R Cassidy

Thomas E Lewis

Michael T Nowak

Kenneth T Robichaud

Richard J D'Amato

Eugene L Langlais

A primer layer that includes a surface-tension modifier dispersed within a polymer binder is disposed between the imaging layer and the substrate of a lithographic printing member to inhibit the production of thermal degradation products that disrupt the oleophilicity of the exposed imaged areas, thereby improving print-making performance and efficiency. In addition, embodiments of the primer layer inhibit static charge buildup during production and during the print-making process.

Lithographic printing with printing members having primer layers

Solubility transitions rather than ablation mechanisms facilitate selective removal of the imaging layer of a lithographic plate, which allows for imaging with low-power lasers that need not impart ablation-inducing energy levels.

Printing members having solubility-transition layers and related methods

Imaging of lithographic printing plates with reduced fluence requirements is accomplished using printing members that have a solid substrate, gas-producing and radiation-absorptive layers over the substrate, and a topmost layer that contrasts with the substrate in terms of lithographic affinity. Exposure of the radiation-absorptive layer to laser light causes this layer to become intensely hot. This, in turn, activates the gas-producing layer, causing rapid evolution and expansion of gaseous decomposition products. The gases stretch the overlying topmost layer to create a bubble over the exposure region, where the imaging layers have been destroyed. If this process is sufficiently explosive, the neck of the bubble expands beyond the diameter of the incident laser beam, tearing the topmost layer and the underlying imaging layers away from the substrate outside the exposed region. The entire affected area is easily removed during a post-imaging cleaning process, resulting in an image spot larger than the incident beam diameter.

Lithographic imaging with reduced power requirements

Apparatus and methods for rapid, efficient production of durable lithographic printing plates by a thermal-transfer process that does not involve ablation. In response to an imaging pulse, a transfer material reduces in viscosity to a flowable state. The material exhibits a higher melt adhesion for a plate substrate than for the carrier sheet to which it is initially bound, so that in a flowable state it transfers completely to the substrate. Following transfer, the carrier sheet, along with untransferred material, is removed from the substrate.

Method and apparatus for laser imaging of lithographic printing members

Laser-imageable printing members and methods for wet lithographic

Lithographic printing plates suitable for imaging by means of laser devices that emit in the near-infrared region. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

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Goffstown, NH, United States of America

Kenneth R Cassidy