Abstract: The present invention is an apparatus for curtain coating a composite layer formed from a plurality of coating compositions onto a moving receiving surface. Edge guides comprising two thin, parallel and closely spaced wires maintain the horizontal extent of the free falling curtain. A flushing and lubricating liquid is supplied to the edge guide. The present invention comprises a distribution body for delivering the flushing and lubricating liquid in laminar flow without initiating stationary waves in the curtain that lead to objectionable coating nonuniformities. The distribution body allows for replacement of the wires without its removal or disassembly. A horizontal conduit near the top of the curtain has an outlet face in contact with the wires that tapers in the upward and downward directions to horizontal edges. The wires pass across the outlet opening within its horizontal diameter. The upper edge of the outlet face positions and supports the wires.

Abstract: The present invention is an edge blade attached to an edge guide for removing an edge of a falling curtain. The edge of the falling curtain is intercepted by the edge blade and is vacuumed away by a vacuum tube disposed near the edge blade wherein the air flow is blocked to said suction means from the outboard direction and directing said suction means to draw air from the inboard direction towards the curtain; and flushing liquid is distributed to encompass the intercepted liquids of the free falling curtain.

Abstract: The present invention is an edge blade attached to an edge guide for removing an edge of a falling curtain. The edge of the falling curtain is intercepted by the edge blade and is vacuumed away by a vacuum tube disposed near the edge blade wherein the blade is extending from the edge guide into the falling curtain to intercept a part of the free falling curtain and positioning the blade above the impingement of the falling curtain on the support wherein the blade is angled into the free falling curtain so that the blade is closest to the support where the part of the free falling curtain is intercepted and farthest from the support at the edge guide. Air to the vacuum tube is blocked from the outboard direction, and the tube is directed to draw air from the inboard direction towards the curtain.

Abstract: 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.

Abstract: 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.

Abstract: The present invention is an apparatus for preparation of a coating hopper. A preparation pan is positioned beneath the hopper lip during hopper preparation wherein flow within the hopper is chaotic and the curtain is not stable. The preparation pan includes edge walls spaced apart from the edge guides to stabilize the unsteady curtain within the preparation pan. The invention minimizes splashing and splattering of the coating liquids thereby minimizing contamination of the coating equipment.

Abstract: In the hopper coating of liquid compositions on moving webs, as in the coating of photographic layers on film supports, the trapping of solid particles or bubbles in the hopper slots causes line defects or streaks in the coated layers. These defects are avoided or reduced by determining the conditions under which the composition can be flowed through one or through a plurality of adjacent slots of the coating hopper at slot Reynolds numbers less than about 10 and flowing the composition through such slot or slots under said conditions.