Abstract: A negative-working lithographic printing plate precursor is disclosed which comprises a grained and anodized aluminum support having a hydrophilic surface and a heat-sensitive coating provided on the hydrophilic surface, the coating comprising hydrophobic thermoplastic polymer particles which are capable of forming a hydrophobic phase in the coating by heat-induced coalescence of the polymer particles. The support is characterized by a surface roughness, expressed as arithmetical mean center-line roughness Ra, which is less than 0.45 ?m. The smooth surface enables to prepare a lithographic printing plate from the mentioned precursor, which is characterized by a high run length during printing.

Abstract: A negative-working lithographic printing plate precursor is disclosed which comprises a grained and anodized aluminum support having a hydrophilic surface and a heat-sensitive coating provided on the hydrophilic surface, the coating comprising hydrophobic thermoplastic polymer particles which are capable of forming a hydrophobic phase in the coating by heat-induced coalescence of the polymer particles. The support is characterized by a surface roughness, expressed as arithmetical mean center-line roughness Ra, which is less than 0.45 &mgr;m. The smooth surface enables to prepare a lithographic printing plate from the mentioned precursor, which is characterized by a high run length during printing.

Abstract: The invention provides an apparatus for collecting ablated material generated by exposure of an imaging layer to a source of radiation, said apparatus comprising a vacuum supply means, and a vacuum head connected to, and in close proximity with, a centrifugal separator, said vacuum head being for direct attachment to a movable mounting means having guide means. The centrifugal separator preferably comprises a reverse flow gas cyclone or a uniflow gas cyclone. The apparatus preferably also includes a filtration system capable of removing any remaining contaminants Typically, the vacuum supply means comprises a vacuum pump, the movable mounting means comprises a carriage to which the vacuum head may be attached and the guide means comprises a guide rail. A method of preparing an imaged member is also disclosed, preferably from an imaging member which comprises a lithographic printing plate precursor comprising a substrate and a metal imaging layer.

Abstract: The present invention provides a method of preparing a lithographic printing plate, said method comprising:

Abstract: The present invention provides a method of preparing a lithographic printing plate, said method comprising: providing a lithographic printing plate precursor comprising: i) a grained and anodized aluminum substrate where the anodic weight is between 6.0 and 20 g/m2, having coated thereon; ii) a metallic layer; and image-wise exposing the precursor on an external drum thermal imaging device. The method provides press ready plates showing high image quality, good press properties and high durability on press without the requirement for the use of costly intermediate film and developer chemistry, and the attendant inconvenience resulting from the use of these materials.

Abstract: A lithographic printing plate precursor comprises a grained and anodised aluminium substrate which has been treated with a solution of water-soluble salt of a Group IVa metal fluoride and over which is provided a metallic layer, preferably a silver layer. Imagewise exposure of the precursor by means of a high intensity laser beam allows for the direct provision of press ready plates showing high image quality and clean background, good press properties and high durability on press, without the requirement for the use of intermediate film and developer chemistry. The plate precursors show enhanced sensitivity on exposure, whereupon removal of the metallic layer occurs in the exposed areas.

Abstract: The invention provides an apparatus for collecting ablated material generated by exposure of an imaging layer to a source of radiation, said apparatus comprising a vacuum supply means, and a vacuum head connected to, and in close proximity with, a centrifugal separator, said vacuum head being for direct attachment to a movable mounting means having guide means. The centrifugal separator preferably comprises a reverse flow gas cyclone or a uniflow gas cyclone. The apparatus preferably also includes a filtration system capable of removing any remaining contaminants Typically, the vacuum supply means comprises a vacuum pump, the movable mounting means comprises a carriage to which the vacuum head may be attached and the guide means comprises a guide rail. A method of preparing an imaged member is also disclosed, preferably from an imaging member which comprises a lithographic printing plate precursor comprising a substrate and a metal imaging layer.

Abstract: A lithographic printing plate precursor comprises a grained and anodised aluminium substrate coated with a layer of metallic silver on top of which is applied a composition comprising an oleophilising agent and a proteolytic enzyme. Imagewise exposure of the precursor by means of a high intensity laser beam allows for the direct provision of press ready plates showing excellent start-up and clean-up properties on press and providing high image quality and high printing durability without the requirement for the use of intermediate film and developer chemistry. On exposure of the plate precursor, removal of the metallic layer occurs in the exposed areas.

Abstract: A lithographic printing plate precursor comprises a grained and anodised aluminium substrate coated with a metallic layer, preferably a silver layer, on top of which is applied a layer of an oleophilic resin. Imagewise exposure of the precursor by means of a high intensity laser beam allows for the direct provision of press ready plates showing increased cleanliness in background areas and providing excellent start-up properties on press, high image quality and improved press durability, without the requirement for the use of intermediate film and developer chemistry, or the need for any post-exposure processing. Lower levels of metal deposition on the substrate surface result in the plate precursors showing enhanced sensitivity on exposure, whereupon removal of the metallic layer occurs in the exposed areas.

Abstract: The invention provides a lithographic printing plate precursor comprising a grained and anodized aluminium substrate having coated thereon a silver halide emulsion layer, the back surface of said substrate being coated with an inert coating which does not chemically or physically interact with an adjacent silver halide layer when two plates are placed in front to back contact. Fogging of the silver halide layer is avoided and the use of the back coating eliminates the requirement for the use of tissue interleaving when wrapping and packing the lithographic printing plate precursors.

Abstract: A method of preparing a lithographic printing plate which involves providing a plate precursor comprising a grained and anodized aluminium substrate coated with a metallic silver layer, imagewise exposing the precursor by means of a high intensity laser beam, and treating the plate by chemical and mechanical means in order to remove stains on the plate surface. On exposure of the plate precursor, removal of the metallic silver layer occurs in the exposed areas. The method provides press ready plates free of background stain, which give a clean, even appearance in exposed areas and show high image resolution and excellent durability on press, while eliminating the requirement for the use of intermediate film and developer chemistry.

Abstract: Laminates of aluminum and plastic form the substrate of printing plate precursors that are suitable for imaging in conventional roll-fed imagesetters or phototypesetters.