摘要:
A method for reducing the tendency toward the formation of ripple imperfections in the coating of a plurality of layers of liquid photographic compositions or moving webs is disclosed. Conditions for coating the compositions are determined according to a given formula to keep the ripple value below 35. The coating compositions are formed into a laminar flow of a plurality of distinct layers including the photographic compositions as upper, middle, and lower layers. The flowing plurality of layers is then received as a layered mass on a moving web. A method for predicting the tendency toward the formation of ripple imperfections in the coating of a multilayer photographic element is also disclosed.
摘要:
A method of reducing the tendency toward formation of ripple imperfections in the coating of multilayer photographic elements is disclosed. Coating compositions are prepared for upper, middle, and lower gelatin-containing layers of a layered mass. The middle layer has a gelatin concentration within three weight percent of each of the upper and lower layers and the upper, middle, and lower layers each have a viscosity that differs from a norm by no more than 15%. A laminar flow of a layered mass including the coating compositions is formed and then received as a layered coating on a moving support. A multilayer photographic element is also disclosed.
摘要:
In a curtain coating apparatus for the coating of photographic film and paper webs and the like, the line of impingement of the curtain on the moving web is controlled by providing a pressure controlled zone on one side of the flowing curtain. Small changes in the static air pressure in the zone cause the position of the curtain to move without disturbing the quality of the curtain. Wetted side walls of the pressure controlled zone can serve as edge guides for the curtain.
摘要:
A versatile, multiple-slot, dual cavity, slide/extrusion hopper for assembling and coating a composite layer comprising a plurality of highly uniform, superposed compositions, and a method for determining the dimensions of the hopper are disclosed. The hopper is suitable for photographic applications and other applications requiring highly uniform layers. The hopper is versatile in that it can accommodate coating compositions that range from Newtonian to substantially shear thinning and in that fewer than the total number of elements may be supplied; the slide offsets between elements are suitable for both merging layers and for the top layer alone. The height of the secondary slot is preferably greater than the height of the primary slot. The method provides optimal cross-sectional shapes for the cavities. Versatility is achieved without greatly increasing the height or thickness of the elements. A formula is provided which gives a straightforward and useful way to determine and scale versatile designs and thereby eliminate much experimentation and reduce the number of coating hoppers required.
摘要:
An inkjet recording element comprising an absorbent support, a porous base layer nearest the support and comprising precipitated calcium carbonate, a porous ink-receiving intermediate layer above the base layer and comprising hydrated alumina, and a porous ink-receiving upper layer above the intermediate layer and comprising a mixture of hydrated and fumed alumina. Also disclosed is an advantageous method of making such inkjet recording materials.
摘要:
A movable trough is taught for establishing a uniform wetting line on the rear face of a curtain coating hopper lip. The trough can be pivoted or moved linearly into a position such that the hopper lip resides in or proximate to the movable trough. The curtain coating apparatus is then started and the coating solution leaving the hopper lip is intercepted by the trough. The coating solution flowing over the lip fills and floods the movable trough. The flooding of the trough forces the coating solution to substantially wet (to a height on the back side of the lip significantly higher than that of natural product flow) the back side of the hopper lip. The movable trough is then retracted from its position immediately beneath the hopper lip and intercepting the coating solution exiting the hopper lip to thereby allow the free-falling curtain to form and begin impingement on the moving support web to be coated. As the curtain forms, the wetting line on the back of the hopper lip naturally retracts toward the tip of the hopper lip thereby forming a uniform wetting line and a uniform curtain.
摘要:
The present invention is a method and apparatus for curtain coating a support with one or more layers of a liquid coating composition. Stripes of a liquid coating composition are formed at the edges of the free falling curtain. These stripes are guided by edge guides which are positioned so that there is an uncoated margin of support at each edge of the support. Liquid is removed from the edges of the free falling curtain near the point of impingement on the support. Drag that emanates from the edge guide is contained within the stripe which is removed thereby producing a more uniform coating. In addition free falling curtains having an extremely low flow rate can be coated that previously were not possible.
摘要:
The present invention is an apparatus for guiding the edge of a free-falling curtain. The apparatus includes first and second slides positioned at the top of the curtain which merge. An edge guide is positioned at the point where the slides merge. A lubricating liquid is provided to each slide surface which flows down each slide and the edge guide to guide the edge of the free-falling curtain. The present invention allows time for surfactant in the lubricating liquid time to diffuse to the surface and promotes dampening of disturbances in the lubricating liquid.
摘要:
An inkjet printing system, comprises an inkjet printer, an ink composition, and an inkjet recording media comprising a support, and coated on the support in order from the support, a porous base layer and a porous uppermost layer, each with particular limitations The inkjet recording media and printer system is manufacturable using low-cost materials in an efficient process requiring only a single coating and drying step and that gives images with excellent gloss, color density, and image quality.
摘要:
A method and apparatus for preventing vortical air flow behind a free-falling curtain in a curtain coating apparatus. There is a critical region within the coating apparatus defined in part by a coating hopper, the free-falling curtain delivered from the coating hopper, a portion of the moving substrate supported on a roller to which the free-falling curtain is delivered, and an air shield located between the roller and the coating hopper. A first intake slot proximate to the moving substrate shield is used to remove boundary-layer air entrained on the moving substrate. A second intake slot positioned within the critical region is used to remove boundary-layer air entrained on the free-falling curtain. Each of the two intake slots is connected to vacuum source. One or two vacuum sources may be used.