Abstract: There is provided a method for producing a stencil for use in screen printing which method comprises coating a screen mesh with liquid photopolymerizable composition, imagewise exposing the coated mesh to radiation to polymerize liquid composition on the mesh in the exposed areas, and removing unexposed liquid composition from the mesh to develop the stencil. Suitably the liquid composition is applied with the screen mesh in contact with a protective film and, after imagewise exposure, the stencil is developed by stripping of the film such that unexposed liquid remains on the film. This provides a simple method of producing a stencil which does not require highly skilled personnel.

Abstract: A photo-curable composite material used for preparing various stencils for screen printing, textile printing or the like, which comprises a flat, flexible and photo-transmitting thin film (A); a flat and flexible film (B); a liquid photo-curable resin and a flat screen material, said films (A) and (B) being air-tightly bonded to each other at the peripheral portion thereof to form a flat inner space therein, said liquid resin being filled in said inner space to form a layer and said screen material also being placed in the inner space substantially in parallel with the inner walls of the films (A) and (B).

Abstract: A method for producing rotary or flat screens having large amounts of open space per unit area comprises plating a master roll or plate having a pattern of conductive metal and non-conductive areas on its surface with a plurality of separate coats of metal coating on the conductive areas to build up a plurality of spaced projecting metal parts having a required thickness, applying a non-electrically-conductive resin onto the entire surface of the metal coating between each plating step, and removing in each step only the portions of the applied resin on the top of each projecting metal part. This is accomplished while the resin is in an undried state with a non-metallic roll or flat plate having a receptivity to the resin to expose the surface of the metal coating formed by plating.

Abstract: Screen printing stencils are prepared by affixing to a printing screen substrate an indicia-defining, ultraviolet-sensitive film and cross-linking the film by exposure to ultraviolet radiation. The coating compositions used to form the film comprise copolyacrylate/polyurethane block copolymers, in which the copolyacrylate blocks are copolymers of at least one hydroxy-containing acrylate and at least one acrylate or methacrylate which may be partially substituted with bromine, ultraviolet initiators and cross-linking monomers. Screen printing stencils are provided which are compatible with both water-based and oil-based inks. The disclosed screen printing stencils are used in improved screen-printing methods.

Abstract: A novel screen stencil comprising a screening material coated with a photo-swellable material, as well as a method of preparing and process of using same, are disclosed.

Abstract: In a method of making decorative panels, a liquid masking material is applied to a surface of a panel, and is cured to form a substantially solid masking layer on the surface. A pattern comprising at least one unmasked area and at least one masked area is formed in the masking layer either simultaneously with the application of the liquid masking material or subsequent to the curing step. The surface of the panel is then treated to render the unmasked areas of the surface of the panel visually distinguishable from the masked areas. In one embodiment of the invention the masking layer is elastomeric and the surface of the panel is treated by sandblasting, after which the masking layer is removed. The entire process may then be repeated to provide a dual density effect. In another embodiment of the invention an asphaltum masking layer is applied to a mirror forming layer on a panel, after which the portions of the mirror forming layer corresponding to the unmasked areas are chemically removed.

Abstract: A method for preparation of the final film used for engraving a flat screen, belt screen or rotary screen for a printing machine. The final film is prepared from a photograph of the image to be reproduced and engraved by known techniques on a screen so as to provide a continuous repetitive pattern on the face of a pile fabric dyed in a continuous print dyeing process.Select areas of photographic images are montaged and put into a repeat pattern within a predetermined outline to establish the basic repeat. Four continuous tone color separations are made of the selected pattern to provide yellow, blue, red and black continuous tone negatives which represent the four colors of the original image. Each color separation is posterized and half toned to provide eight positive films. The films are selectively combined, blown up to the desired repeat size to provide a negative or positive which is used to prepare a flat bed screen or rotary screen for an otherwise conventional printing process.

Abstract: A duplicating stencil comprising a perforated or porous ink-permeable sheet composed of a synthetic resinous film or a metal sheet or film of aluminum or copper. The perforated or porous ink-permeable sheet is coated with a binding agent coating which coating may contain softeners or fillers. On the binder coating there can be applied a coating of hot-seal adhesive which in turn is overcoated with an infra-red light permeable coating. Alternatively, the hot-seal adhesive coating can be applied to a separate sheet of paper, synthetic resinous film or metallic sheet, over-coated with an infra-red permeable coating and placed together with the sheet coated with the binding agent prior to subjection to infra-red rays.

Abstract: A method of making a relatively thick dry film stencil for uses such as depositing solder paste through a screen chase. A stencil consisting of four mil thick dry film photoresist is formed by passing the photoresist layers through a roller and laminating them onto a support screen. The outer protective film coatings are removed and the film photoresist developed. It is then placed in a chase with the developed film face on the bottom. The solder paste is then squeegeed through the screen and deposited on a desired part. An alternate method of making the stencil uses two layers of dry film photoresist laminated together with the protective film coating removed. The stencil is cut to the size needed and exposed. Using a hydraulic press, the stencil is then connected to a screen in a chase by applying a pressure of 250 psi at 300.degree. F. for 10 seconds.

Abstract: An improved cylindrical printing screen having aperatures located such that their geometric centers define an array of equilateral triangles each having one side which defines a 15 degree angle with respect to the circumferential direction, another side which defines a 15 degree angle with respect to the longitudinal direction and a third side which defines a 45 degrees angle with respect to both the circumferential and longitudinal directions of the cylinder is disclosed.