Abstract:
Certain types of lithographic printing plates are activated by preheating while certain other types are post heated to harden the coating. A platen having a large mass compared to the mass of a printing plate is heated and maintained in the exact temperature range to which the printing plate is to be heated. A printing plate is brought into heat exchange contact with the platen for the period of time required to heat the printing plate to the temperature of the platen. The printing plate may be heated while resting in a fixed position on the platen or while the printing plate is carried over the platen by a continuous thin metal conveyor belt in intimate contact with both the platen and printing plate.
Abstract:
A substrate is coated with a first material which is soluble in a first solvent, whereupon a second material which is strongly adherent to the first material and insoluble in the first solvent is selectively applied by an ink jet printer. The substrate is then developed in the first solvent to establish the image. In a preferred embodiment the substrate is hydrophilic, the first material is a negative working photosensitive material, and the second material is a transparent adhesive, which permits curing the first material by exposure to actinic light after the development step. The adhesive is then removed. In an embodiment directed to a waterless plate the substrate includes a surface coating of silicone, and the first material is a primer which promotes adhesion of a second material in the form of an oleophilic adhesive which is selectively applied. The primer is then developed to expose the silicone on the non-image areas. The ink carrying image areas are formed by the adhesive, which in this embodiment is not removed.
Abstract:
A substrate is coated with a first material which is soluble in a first solvent, whereupon a second material which is strongly adherent to the first material and insoluble in the first solvent is selectively applied by an ink jet printer. The substrate is then developed in the first solvent to establish the image. In a preferred embodiment the substrate is hydrophilic, the first material is a negative working photosensitive material, and the second material is a transparent adhesive, which permits curing the first material by exposure to actinic light after the development step. The adhesive is then removed. In an embodiment directed to a waterless plate the substrate includes a surface coating of silicone, and the first material is a primer which promotes adhesion of a second material in the form of an oleophilic adhesive which is selectively applied. The primer is then developed to expose the silicone on the non-image areas. The ink carrying image areas are formed by the adhesive, which in this embodiment is not removed.
Abstract:
A substrate metal such as aluminum or titanium, usually in the form of a web, is anodized to form a porous unsealed oxide coating. An inexpensive core metal such as copper or chromium is then electrodeposited in the pores of the oxide coating to form metal nodules extending above the oxide coating in a bulbous, undercut configuration. A second metal, usually an expensive catalytic metal, is deposited onto the surface of the core metal nodules by electro or chemical deposition. A large surface area of catalyst is formed with the use of a minimum amount of catalyst metal. The nodules may be liberated from the substrate metal surface by dissolving the oxide layer and releasing discrete particles to form a fine catalyst powder.
Abstract:
A method and apparatus for cutting continuous material to length. Lithographic printing plates are cut from a substantially continuous lithographic aluminum web by a plurality of aligned shear units displaced from each other longitudinally along the web.
Abstract:
A process for forming printing plates using an imaging sheet which carries a layer of microcapsules containing a photohardenable composition; the imaging sheet is preferably assembled with a printing plate support, exposed and subjected to pressure to rupture the microcapsules and differentially transfer the photohardenable composition to the support; the transferred composition is hardened to provide ink-receptive images useful in printing.
Abstract:
Anodizing current is prevented from being carried downstream by an aluminum web after anodizing in a continuous anodizing process. An anode is placed in a post-treatment cell containing an electrolyte which is electrically connected to a cathode in the anodizing cell via a source of DC current which is independent of the source of anodizing current. The web polarity is switched from positive to negative and a voltage greater than the exist voltage of the web is applied to prevent anodizing current from being carried downstream in the web after anodizing.
Abstract:
Process for making a lithographic printing plate having an oleophilic amplified image prepared by(a) providing a silicated aluminum substrate with a hydrophilic, anionic, negatively charged surface and a layer on said surface of a light sensitive, cationic, positively charged, water soluble diazonium material having at least two reactive sites per molecule, each reactive site being capable of being chemically altered by actinic light or chemically reacted with an anionic material;(b) selectively and incompletely exposing the diazo layer to actinic light to alter only a portion of the reactive sites thereby adhering the diazo material to the substrate in the exposed areas;(c) coupling the diazo layer with an anionic material to reinforce diazo in the exposed areas in situ and remove diazo from the unexposed areas by contacting the substrate after exposure with an anionic material in water in a quantity and for a time sufficient to couple the anionic material with the diazo and dissolve the coupled product from the unexposed areas; and(d) rinsing with water to provide a printing plate having a reinforced, oleophilic image and a clean, hydrophilic background.
Abstract:
Anodized aluminum having a porous, unsealed anodic oxide layer is provided with a polymeric coating over the oxide layer that is substantive to a sublimatable dye. A sublimated dye forms a design or image in the oxide layer and the polymeric coating. Single and multi-color designs and images can be used for nameplates, dials and signs.
Abstract:
A method of immersion casting objects from molten metal, by crystallizing the metal outwardly from a heat-absorbing forming element such that upon removal from the molten metal bath, the solidified object has an internal surface defined by the shape of the forming element, and an outer surface that features random crystallization and a high degree of texture. The method can be facilitated by the interaction of the forming element and molten metal with molten salt provided as a layer on the molten metal. When the object is cast from a high purity metal such as aluminum or copper, the exposed crystal structure is especially random and highly reflective and can be enhanced by electro-chemical brightening.