Abstract: The present disclosure relates generally to signal encoding for flexographic printing plates. One aspect is a flexographic, photopolymer printing plate having transparent layers to allow encoded signal printed or laser ablated thereon to be detectable from both sides of the printing plate. Another aspect is a flexographic, photopolymer printing plate having an encoded signal formed in a photocured layer. Still another aspect is a system for tracking such printing plates, including managing location, print impression count, location tracking, etc. Other aspects are described as well.

Abstract: The present disclosure is directed to a system and method configured for curing non-reactive photopolymer collected by an absorbent blotting material during thermal processing of flexographic printing elements. Uncured non-reacted portions of the photopolymer are removed by contacting the one or more layers of photopolymer with the web of absorbent blotting material at an elevated temperature to soften or liquefy the uncured non-reacted portions of the one or more layers of photopolymer and absorb the softened or liquefied uncured non-reacted portions into the absorbent web of absorbent blotting material. The web of absorbent blotter material containing the absorbed softened or liquefied non-reacted portions of the photopolymer is exposed to actinic radiation from the one or more UV light sources to crosslink and cure the softened or liquefied non-reacted portions of the photopolymer.

Abstract: A method of producing a photocured structure comprising a backing layer for coupling to a relief image printing plate or as an integral all-in-one structure comprising a backing layer and a relief image printing layer. The photocured structure may be formed using a continuous liquid interphase method or three-dimensional plating to selectively crosslink and cure a photocurable composition. The backing layer may comprise a lattice or series of openings of the lattice where the placement and density of the openings is controlled.

Abstract: A method of preparing a film negative including the steps of dispersing a UV ink in a desired pattern on a UV printing substrate; and curing the UV ink with a source of actinic radiation to crosslink and cure the UV ink and create the UV printed polymer layer in the desired pattern. The UV ink is at least substantially solvent-free and printing substrate does not contain an adhesive layer or an ink-receptive layer and is not been modified to be ink-receptive. The film negative may be used in a process of making a flexographic printing element.

Abstract: The present disclosure is directed to a thermal developing assembly that is configured to reduce (or eliminate) the reactivity of contaminants and/or unreacted photosensitive material associated with forming a relief image on a photosensitive printing element during thermal development. The thermal developing assembly is configured to reduce (or eliminate) the reactivity of a byproduct associated with forming a relief image on a photosensitive printing element, the byproduct including but not limited to, contaminants within vapors (e.g., fumes), contaminants within condensate, unreacted photosensitive material, and combinations thereof.

Abstract: A method of creating an image film negative capable of masking non-image areas of one or more layers of liquid photopolymer during a step of imagewise exposing the one or more layers of liquid photopolymer to actinic radiation. The method includes the steps of (a) providing an image film negative comprising a negative of an image on the image film negative, wherein the negative of the image comprises a pattern of opaque areas; and (b) inkjet printing a filtering layer on portions of the image film negative not covered by the pattern of opaque areas, wherein the portions of the image film negative comprise portions where it is desirable to modulate intensity of actinic radiation in a subsequent exposure step.

Abstract: A method of producing a relief image or mold from a liquid photopolymer resin, said method comprising the steps of: a) placing an image film onto an exposure glass; b) placing a cover film over the image film and drawing a vacuum c) placing substrate material on a bottom glass d) casting a liquid photopolymer resin layer onto the substrate material; d) laminating a flexible polyester sheet onto a backside of the liquid photopolymer resin layer as the liquid photopolymer resin layer is being cast onto the substrate material; and e) exposing the liquid photopolymer resin layer through the image film to selectively crosslink and cure the photopolymerizable resin layer and form a cured relief image, wherein said depth of the cured relief image is less than the height of the cast liquid photopolymerizable resin.

Abstract: A photocurable relief image printing blank comprising: (a) a support layer; (b) one or more photocurable layers disposed on the support layer, wherein the one or more photocurable layers comprise: i) a binder; ii) one or more monomers; iii) an alpha-aminoketone photoinitiator; and optionally, iv) an additive selected from the group consisting of phosphites, phosphines, thioether amine compounds, and combinations of one or more of the foregoing; (c) a laser ablatable masking layer disposed on the one or more photocurable layers, the laser ablatable masking layer comprising a radiation opaque material; and (d) optionally, a removable coversheet. Upon exposure and development, the resulting relief image printing element does not degrade if left under ambient lights for an extended period of time.

Abstract: A method of making a relief image printing element comprising a plurality of relief printing dots. The method includes the steps of imagewise exposing at least one photocurable layer to actinic radiation to selectively crosslink and cure portions of the at least one photocurable layer; and developing the relief image printing element to separate and remove uncrosslinked and uncured portions of the at least one photocurable layer to reveal the relief image therein. The at least one photocurable layer includes a photoinitiator exhibiting a quantum yield of initiation (Qi) of more than 0.05 at a 365 nm wavelength. The substrate has an optical density from 0.5 to 5 in the wavelength range of 365 nm to 450 nm but preferably allows transmission of from 0.1% to 10% of incident light in the wavelength range of 365 nm to 450 nm.

Abstract: A method of producing a flexographic printing plate using a continuous liquid interphase is provided herein. This method allows for significantly reduced production times and fewer preparation steps compared to standard non-continuous techniques and results in less waste than typical methods for preparing flexographic printing plates. The printing plate provided by using continuous liquid interphase production results in a printing plate with desirable elastomeric elongation, desirable hardness, plate thickness in the range of 0.030 inches to 0.250 inches, and comprises printing dots with desirable characteristics.

Abstract: An apparatus for thermally processing a relief image printing element and a method of using the same are described. The printing element comprises at least one photopolymer layer and is selectively exposed to actinic radiation to crosslink portions of the at least one photopolymer layer. The apparatus comprises: (a) means for supporting the printing element; (b) heating means for melting or softening non-crosslinked portions of the at least one photopolymer layer; (c) at least one rotatable roll that is capable of bringing a blotting material into contact with the at least one photopolymer layer to remove the melted or softened non-crosslinked portions of the at least one photopolymer layer; and (d) an element arranged adjacent to the at least one rotatable roll for removing non-crosslinked photopolymer remaining on a surface of the at least one rotatable roll after step c). The apparatus may alternatively be operated without a blotting material.

Abstract: A method of producing a flexographic printing plate using a continuous liquid interphase is provided herein. This method allows for significantly reduced production times and fewer preparation steps compared to standard non-continuous techniques and results in less waste than typical methods for preparing flexographic printing plates. The printing plate provided by using continuous liquid interphase production results in a printing plate with desirable elastomeric elongation, desirable hardness, plate thickness in the range of 0.030 inches to 0.250 inches, and comprises printing dots with desirable characteristics.

Abstract: A method of making a relief image printing element from a photosensitive printing blank is described. The photosensitive printing blank comprises a laser ablatable mask layer disposed on at least one photocurable layer and the laser ablatable mask layer is selectively laser ablated to create an in situ mask and uncover portions of the at least one photocurable layer. The method includes a) pushing the photosensitive printing blank through a nip formed by a textured roller and a backing roller, wherein the textured roller contacts the in situ mask and the uncovered portions of the at least one photocurable layer; and b) exposing the at least one photocurable layer to at least one source of actinic radiation through the in situ mask to selectively cross link and cure the portions of the at least one photocurable layer not covered by the in situ mask. A defined topographical pattern is transferred from the textured surface of the roller to the at least one photocurable layer.

Abstract: A method of selectively exposing a liquid photopolymer printing blank to actinic radiation to create a relief image printing plate and a liquid platemaking exposure system. The method includes: (1) positioning a programmable screen programmed with an image file of a desired image between the top glass and an upper source of actinic radiation; (2) exposing the layer of liquid photopolymer to actinic radiation from the upper source of actinic radiation through the programmable screen to crosslink and cure at least a portion of the liquid photopolymer adjacent to the backing sheet and create a floor layer therein; and (3) imagewise exposing the layer of liquid photopolymer to actinic radiation from a lower source of actinic radiation through a negative of the relief image to crosslink and cure selective portions of the liquid photopolymer on the floor layer and create the relief image therein.

Abstract: A photocurable relief image printing blank comprising: (a) a support layer; (b) one or more photocurable layers disposed on the support layer, wherein the one or more photocurable layers comprise: i) a binder; ii) one or more monomers; iii) a photoinitiator; iv) an additive selected from the group consisting of phosphites, phosphines, thioether amine compounds, and combinations of one or more of the foregoing; and v) an additional component comprising amine moieties; (c) a laser ablatable masking layer disposed on the one or more photocurable layers, the laser ablatable masking layer comprising a radiation opaque material; and (d) optionally, a removable coversheet. Upon exposure and development, the resulting relief image printing element does not degrade if left under ambient UV lights for an extended period of time.