摘要:
Cleaning compositions for ablation-type lithographic printing plates include solvent, non-solvent and lubricating components, the vapor pressures and concentrations of the various components being chosen such that the mixture never becomes too rich in solvent. In this way, the solvent's effect is directed primarily at thermal byproducts, which, because they are exposed and already partly decomposed, are more vulnerable to solvent action than the intact, anchored plate constituents in unimaged regions. The compositions are used in conjunction with mechanical rubbing of the plate surface following imaging.
摘要:
Lithographic imaging using non-ablative printing members combines the benefits of simple construction, the ability to utilize traditional metal base supports, and amenability to imaging with low-power lasers that need not impart ablation-inducing energy levels. A representative printing member has a hydrophilic metal substrate and, thereover, first and second layers. The first layer has a thickness and an exposure surface and comprises a material that absorbs imaging radiation. The second layer overlies the first layer and is oleophilic and substantially transparent to imaging radiation. Exposure to imaging radiation causes the first layer and the substrate to irreversibly detach without substantial ablation, thereby facilitating removal, by subjection to the cleaning liquid, of the first and second layers where detachment has taken place.
摘要:
Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. 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 and/or a fluid to which ink will not adhere that differs from that of unexposed areas.
摘要:
A universal cable clamp for coupling a wide variety of electrical cables to an electrical box is capable of accepting metal or non-metallic sheathed cables. The cable clamp includes upper and lower clamping plates and a front wall having at least one opening for receiving the cable. The upper and lower clamping plates are coupled together by bendable coupling arms. A fastener extends through the upper and lower clamping plates and into the electrical box to deform the bendable coupling arms while the cable is clamped between the upper and lower clamping plates. The opening in the front wall in embodiments is oval-shaped and is dimensioned to allow a non-metallic sheathed cable to pass through, while preventing the metal sheath of a metal sheathed cable from passing through. The clamp provides a grounding connection of the metal cables and conduits. The cable clamp accommodates thick or thin steel and aluminum flex metal conduits, armored cable, metal clad cable and non-metallic cable.
摘要:
Seamless, sleeve-shaped dry and wet lithographic printing members that can be recycled after use are disclosed, along with methods for their manufacture and use. The members include a strong, durable, hollow cylinder or sleeve that is attached to the plate mandrel or cylinder jacket of an offset printing press or platemaking apparatus. Surrounding the sleeve is a layer of a material, preferably polymeric in nature, which is characterized by efficient, ablative absorption of laser radiation, as well as other layers that facilitate imaging and subsequent printing. A layer disposed beneath the ablatable layer reflects unabsorbed imaging radiation back into the ablatable layer.
摘要:
Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. 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.
摘要:
Lithographic printing constructions and methods of imaging them. The constructions include a grained-metal substrate, a protective layer that can also serve as an adhesion-promoting primer, and an ablatable oleophilic surface layer. In operation, imagewise pulses from an imaging laser interact with the surface layer, causing ablation thereof and, probably, inflicting some damage to the underlying protective layer as well. The imaged plate may then be subjected to a solvent that eliminates the exposed protective layer, but which does no damage either to the surface layer or to the unexposed protective layer lying thereunder.
摘要:
Lithographic printing plates suitable for imaging by means of laser devices. Laser output ablates one or more plate layers, 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. The plates also include a secondary ablation layer that ablates only partially, and in a controlled fashion, as a result of destruction of overlying layers.
摘要:
A method of and apparatus for imaging a lithographic plate having a printing surface by exposing the printing surface to plasma jet discharges between the plate and a plasma jet nozzle spaced close to the printing surface of the plate. These plasma jet discharges are sufficient to ablate or otherwise transform one or more layers of the printing surface, thereby changing the affinity of the printing surface for ink and/or water at the points thereof exposed to the discharges so as to produce image spots on the plate.
摘要:
A method of imaging a lithographic plate having a printing surface comprises exposing the printing surface to plasma jet discharges between the plate and a plasma jet nozzle spaced close to the printing surface of the plate. These plasma jet discharges are sufficient to remove a layer or layers of the plate to thereby change the affinity of the printing surface for ink and/or water at the points thereof exposed to the discharges, thereby producing image spots on the plate.