Abstract: A method of flood exposing a photocurable printing blank to actinic radiation from a UV LED light source, wherein a high intensity UV LED light source is modulated to a lower intensity. The method includes the steps of: (a) positioning the photocurable printing blank in an exposure unit, wherein the exposure unit comprises one or more high intensity UV LED light sources; (b) modulating intensity of the one or more high intensity UV LED light sources to a lower intensity; and (c) flood exposing the photocurable printing blank through the photographic negative or the digitally imaged mask layer to actinic radiation from the one or more modulated UV LED light sources.

Abstract: A photosensitive printing blank having is described. The photosensitive printing blank comprises at least one photocurable layer that is capable of being selectively crosslinked and cured upon exposure to actinic radiation at a desired wavelength region comprising (a) at least one elastomeric binder, (b) at least one ethylenically unsaturated monomer, (c) a photoinitiator having a favorable absorption profile in the desired wavelength region used for exposing the at least one photocurable layer to actinic radiation, and (d) a dye, wherein the dye exhibits a suitable percent transmission as measured with a UV spectrophotometer at the desired wavelength region used for exposing the at least one photocurable layer to actinic radiation, and optionally an infrared ablatable layer disposed on the at least one photocurable layer. A method of making a relief image printing element from the photosensitive printing blank is also described.

Abstract: A method of flood exposing a photocurable printing blank to actinic radiation from a UV LED light source, wherein a high intensity UV LED light source is modulated to a lower intensity. The method includes the steps of: (a) positioning the photocurable printing blank in an exposure unit, wherein the exposure unit comprises one or more high intensity UV LED light sources; (b) modulating intensity of the one or more high intensity UV LED light sources to a lower intensity; and (c) flood exposing the photocurable printing blank through the photographic negative or the digitally imaged mask layer to actinic radiation from the one or more modulated UV LED light sources.

Abstract: A method is provided for processing a flexographic printing blank to produce a relief image printing element capable of printing cleanly. The method provides a flexographic printing blank comprising: (i) a support layer; (ii) at least one photocurable layer disposed on the support layer, and (iii) a laser ablatable mask layer disposed on the at least one photocurable layer. The laser ablatable mask layer is laser ablated to create an in situ negative in the laser ablatable mask layer. Thereafter, a barrier layer is disposed on the laser ablatable mask layer. The photocurable layer is exposed to actinic radiation through the barrier layer and the laser ablatable mask layer; and the imaged and exposed flexographic printing blank is developed to reveal the relief image therein. The resulting flexographic relief image printing element is capable of printing cleanly and of resisting paper fibers, dust, and ink during a print run.

Abstract: A clean running flexographic relief image printing element and a method of making the same is described. The relief image printing element comprises (a) a backing layer; (b) a floor layer disposed on the backing layer and comprising a photopolymer containing a silicone monomer or silicone oil, wherein the cured floor layer has a surface energy of between about 18 to about 25 dynes/cm; (c) a cap layer disposed on the floor layer and comprising a photocurable composition that is capable of being imagewise exposed to actinic radiation to create a relief image therein, wherein the cap layer has a surface energy of between about 30 and about 40 dynes/cm; and (d) a removable cover sheet. The differential of surface energies between the floor layer and the cap layer increases how clean the plate will print over time.

Abstract: A photosensitive printing blank having is described. The photosensitive printing blank comprises at least one photocurable layer that is capable of being selectively crosslinked and cured upon exposure to actinic radiation at a desired wavelength region comprising (a) at least one elastomeric binder, (b) at least one ethylenically unsaturated monomer, (c) a photoinitiator having a favorable absorption profile in the desired wavelength region used for exposing the at least one photocurable layer to actinic radiation, and (d) a dye, wherein the dye exhibits a suitable percent transmission as measured with a UV spectrophotometer at the desired wavelength region used for exposing the at least one photocurable layer to actinic radiation, and optionally an infrared ablatable layer disposed on the at least one photocurable layer. A method of making a relief image printing element from the photosensitive printing blank is also described.

Abstract: A method of preparing a photosensitive printing blank, the method comprising the steps of: a) coating a slip film onto a coversheet and drying the slip film; and depositing at least one layer of photosensitive material on top of the slip film coated coversheet and laminating a substrate layer to the exposed surface of the photosensitive material. The slip film comprises: i) a polymer selected from the group consisting of polystyrene and polyvinylpyrrolidone; ii) optionally, an additive. The slip film at least substantially eliminates the formation of hot spots during an analog plate making process.

Abstract: A clean running flexographic relief image printing element and a method of making the same is described. The relief image printing element comprises (a) a backing layer; (b) a floor layer disposed on the backing layer and comprising a photopolymer containing a silicone monomer or silicone oil, wherein the cured floor layer has a surface energy of between about 18 to about 25 dynes/cm; (c) a cap layer disposed on the floor layer and comprising a photocurable composition that is capable of being imagewise exposed to actinic radiation to create a relief image therein, wherein the cap layer has a surface energy of between about 30 and about 40 dynes/cm; and (d) a removable cover sheet. The differential of surface energies between the floor layer and the cap layer increases how clean the plate will print over time.

Abstract: A method of preparing a photosensitive printing blank, the method comprising the steps of: a) coating a slip film onto a coversheet and drying the slip film; and depositing at least one layer of photosensitive material on top of the slip film coated coversheet and laminating a substrate layer to the exposed surface of the photosensitive material. The slip film comprises: i) a polymer selected from the group consisting of polystyrene and polyvinylpyrrolidone; ii) optionally, an additive. The slip film at least substantially eliminates the formation of hot spots during an analog plate making process.