Abstract: A method of controlling surface roughness of the relief surface of a flexographic printing element during thermal processing is provided. An imaged and exposed relief image printing element is thermally developed to remove the portions of at least one layer of photopolymer that are not crosslinked and cured by a) heating the at least one layer of photopolymer to soften uncured portions of the at least one layer of photopolymer; b) causing contact between the at least one layer of photopolymer and a blotting material; and c) separating the blotting material from the at least one layer of photopolymer. Thereafter, a smooth material is inserted between the surface of the at least one layer of photopolymer and the blotting material. In the alternative, a polymeric film is laminated onto the relief image printing element using heat and pressure.

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 combined laminating and exposing apparatus for exposing a photosensitive printing blank to actinic radiation in a printing plate manufacturing system and a method of using the same are disclosed. The photosensitive printing blank comprises a backing layer, at least one photocurable layer disposed on the backing layer, and a laser ablatable mask layer disposed on the at least one photocurable layer, wherein the laser ablatable mask layer is laser ablated to create an in situ negative in the laser ablatable mask layer. The exposing apparatus comprises: (a) a laminating apparatus for laminating an oxygen barrier layer to a top of the laser ablated mask layer; (b) a conveyor; (c) a first exposing device for imagewise exposing the at least one photocurable layer to actinic radiation, and (d) a second exposing device for exposing the at least one photocurable layer to actinic radiation through the backing layer.

Abstract: A combined laminating and exposing apparatus for exposing a photosensitive printing blank to actinic radiation in a printing plate manufacturing system and a method of using the same are disclosed. The photosensitive printing blank comprises a backing layer, at least one photocurable layer disposed on the backing layer, and a laser ablatable mask layer disposed on the at least one photocurable layer, wherein the laser ablatable mask layer is laser ablated to create an in situ negative in the laser ablatable mask layer. The exposing apparatus comprises: (a) a laminating apparatus for laminating an oxygen barrier layer to a top of the laser ablated mask layer; (b) a conveyor; (c) a first exposing device for imagewise exposing the at least one photocurable layer to actinic radiation, and (d) a second exposing device for exposing the at least one photocurable layer to actinic radiation through the backing layer.

Abstract: A method of controlling surface roughness of a flexographic printing element during thermal processing is provided. An imaged and exposed relief image printing element is thermally developed to remove the portions of at least one layer of photopolymer that are not crosslinked and cured by a) heating the at least one layer of photopolymer to a sufficient temperature to soften uncured portions of the at least one layer of photopolymer; b) causing contact between the at least one layer of photopolymer and a blotting material, wherein when the blotting material contacts the at least one layer of photopolymer, the softened uncured photopolymer portions of the at least one layer of photopolymer are absorbed into the blotting material; and c) separating the blotting material from the at least one layer of photopolymer. Thereafter, a smooth material is inserted between the surface of the at least one layer of photopolymer and the blotting material.

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.