Abstract: A method for making a lithographic printing plate includes the steps of providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, and a coating provided on the hydrophilic surface or the hydrophilic layer, wherein the coating includes an image recording layer including hydrophobic thermoplastic polymer particles and wherein the image recording layer or an optional other layer of the coating further includes an infrared light absorbing agent; image-wise exposing the precursor to infrared light having an energy density of 190 mJ/cm2 or less; developing the exposed precursor by removing unexposed areas in a processing liquid; baking the plate thus obtained by keeping the plate at a temperature above the glass transition temperature of the thermoplastic particles during a period between 5 seconds and 2 minutes.

Abstract: A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer particle comprising aluminum hydroxide or aluminum oxide and having an average particle size larger than 0.3 ?m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.

Abstract: A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) applying on the hydrophilic surface of the web a coating comprising a phenolic resin; (iii) drying the coating by supplying heat to the coated web; (iv) a cooling step wherein the web temperature is reduced at an average cooling rate which is higher than if the web would be kept under ambient conditions but not higher than 30° C./s; and (v) winding the precursor on a core or cutting the precursor into sheets. The cooling step provides a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.

Abstract: A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) applying on the hydrophilic surface of the web a coating comprising a phenolic resin; (iii) drying the coating; (iv) a heating step wherein the web temperature is maintained above the glass transition temperature of the phenolic resin Tg during a period of between 0.1 and 60 seconds; (v) a cooling step wherein the web temperature is reduced at an average cooling rate which is higher than if the web would be kept under ambient conditions but not higher than 30° C./s; and (vi) winding the precursor on a core or cutting the precursor into sheets. The heating step and the cooling step provide a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.

Abstract: A method of printing is disclosed which comprises the steps of (i) providing a lithographic printing plate precursor comprising a support and a heat- or light-sensitive coating; (ii) image-wise exposure of the coating to heat or light; (iii) prior to step (ii) or (iv), mounting the lithographic printing plate precursor in a printing unit of a printing press, said printing unit comprising a dampening system and an inking system; (iv) development by supplying a processing liquid to the coating by means of the dampening system, thereby obtaining a lithographic printing plate; (v) printing by supplying single-fluid ink or driographic ink to the lithographic printing plate by means of the inking system. This method allows on-press processing of printing plate materials that require wet processing.

Abstract: A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) coating a layer comprising a phenolic resin on the hydrophilic surface of the web; (iii) drying the layer; (iv) a heating step wherein the web temperature is maintained above 150° C. during a period of between 0.1 and 60 seconds; (v) winding the coated web on a core or cutting the coated web into sheets. The short on-line heating step provides a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.

Abstract: A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) applying on the hydrophilic surface of the web a coating comprising a phenolic resin; (iii) drying the coating by supplying heat to the coated web; (iv) a cooling step wherein the web temperature is reduced at an average cooling rate which is higher than if the web would be kept under ambient conditions but not higher than 30° C./s; and (v) winding the precursor on a core or cutting the precursor into sheets. The cooling step provides a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.

Abstract: A method for treating a micro-emulsion that can be used for removing the ink-accepting areas of a lithographic printing master is disclosed, which enables to recycle the water from the used micro-emulsion. The method comprises the heating of the micro-emulsion to a temperature above 50° C. thereby obtaining an aqueous phase and an organic phase and separating the aqueous phase from the organic phase.

Abstract: A method for making a lithographic printing plate is disclosed wherein the method comprises the steps of: (i) providing a lithographic printing plate precursor comprising a photosensitive coating on a substrate having a hydrophilic surface, (ii) image-wise exposing said photosensitive coating, (iii) developing said exposed coating to form an image on said substrate and optionally gumming the plate and (iv) baking the image on the plate, wherein said baking step is carried out within a dwell-time of less than 1 minute and wherein the chemical resistance of the coating against printing liquids and press chemicals is improved. This baking step is preferably carried out by exposing the printing plate to an infrared radiation source, preferably in a dynamic configuration.

Abstract: A method is disclosed for removing ink-accepting areas from a printing master by laser ablation, characterized in that the printing master comprises a substrate which comprises a support and a base layer, wherein the base layer contains a crosslinked hydrophilic binder and a metal oxide. The base layer prevents deterioration of the quality of the substrate due to the laser ablation. In a preferred embodiment, the same substrate is used in a number of consecutive printing cycles of on-press coating, on-press exposure, printing and cleaning.

Abstract: A method for removing ink-accepting areas of a lithographic printing master is disclosed which enables to recycle the lithographic substrate of the printing master. The method comprises after a cleaning step a treatment of the recycled substrate with an aqueous solution having a pH<7.

Abstract: A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer, which is a cross-linked polysiloxane particle, having a particle size larger than 0.6 &mgr;m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.

Abstract: A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer particle comprising aluminum hydroxide or aluminum oxide and having an average particle size larger than 0.3 &mgr;m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.

Abstract: A method of lithographic printing is disclosed which comprises the steps of unwinding a web of a flexible lithographic base from a supply spool, the lithographic base having a hydrophilic surface, wrapping the lithographic base around a cylinder of a printing press, applying on the lithographic base an image-recording layer which is removable in a single-fluid ink or can be rendered removable in a single-fluid ink by exposure to heat or light, image-wise exposing the image-recording layer to heat or light, processing the image-recording layer by supplying single-fluid ink, thereby obtaining a printing master, printing by supplying single-fluid ink to the printing master which is mounted on a plate cylinder of the printing press; and removing the printing master from the plate cylinder, preferably by winding up on an uptake spool.

Abstract: An off-press plate-making apparatus is provided which comprises an apparatus for removing the lithographic image from the substrate of a used printing master and an apparatus for recoating the recycled substrate with a new image-recording layer. The off-press cleaning and recoating of the substrate provides a short press down-time. The recoated substrate forms an imaging material which can be exposed either on-press in a digital press comprising an integrated exposure apparatus or off-press in an exposure apparatus, which can be integrated in the plate-making apparatus or mechanically coupled thereto.

Abstract: A method for removing ink-accepting areas of a lithographic printing master is disclosed which enables to recycle the lithographic substrate of the printing master. The method comprises the following step which is preferably carried out on-press: applying a cleaning liquid to the printing master, the cleaning liquid being an emulsion of an organic compound in water, further comprising a compound according to formula (I): wherein X=OH, O−, a polymer backbone.

Abstract: A direct-to-plate method for obtaining a high quality lithographic printing plate is disclosed. The method comprises the application of a continuous layer of a radiation sensitive solution onto a lithographic substrate by means of an ink-jet printhead. Hereby waste of coating solution and contamination of the environment are avoided.

Abstract: A direct-to-plate method of lithographic printing is disclosed wherein a printing press is used that is coupled to a coating apparatus and to a cleaning apparatus; wherein the coating apparatus applies an image-recording layer on a substrate so as to obtain a printing plate, which is mechanically transferred to the printing press; and wherein, after the print job, the printing plate is mechanically transferred to the cleaning apparatus wherein the substrate is recycled, so that the recycled substrated can be reused in a next cycle of coating, printing and cleaning. The off-press coating and the off-press cleaning step provide a fully automated printing method wherein the press down-time is minimized. The method comprises also an off-press or an on-press exposure step.

Abstract: A printing method is disclosed wherein a grained and anodized aluminum support is coated with an image recording layer comprising hydrophobic thermoplastic polymer particles. The heat-sensitive imaging material thus obtained is then image-wise exposed and processed, thereby obtaining a material having a lithographic image which consists of hydrophobic printing areas on a hydrophilic support and which is used as a printing master in a printing press. After the press run, the lithographic support is recycled by removing the hydrophobic printing areas from the hydrophilic surface of the aluminum support. The recycled support is then reused in a next cycle of coating, exposing, processing and printing. By using a grained and anodized aluminum support having a hydrophilic surface with a surface roughness, expressed as arithmetical mean center-line roughness Ra, which is less than 0.45 &mgr;m, the run length of the printing master is improved.

Abstract: A method of making a lithographic image is disclosed, which comprises the steps of providing a lithographic imaging material comprising a support and a heat- or light-sensitive coating; image-wise exposure of the coating to heat or light, thereby obtaining a latent image in said coating, the latent image consisting of a set of exposed areas in the coating and a set of non-exposed areas in the coating; development of the latent image by supplying a processing liquid to the coating and evacuating, by means of a suction device, the processing liquid together with (i) substances removed from the exposed areas without removing such substances from the non-exposed areas or together with (ii) substances removed from the non-exposed areas without removing such substances from the exposed areas.