Eastman-kodak Company

James E Conroy

Kenneth J Ruschak

Steven J Weinstein

Nayyir F Irani

A process is provided for preparing improved aqueous gelatin compositions for improved coatings, particularly light sensitive photographic coatings, wherein a viscosity increasing amount of a copolymer of an alkali metal or ammonium salt of a sulfonic acid containing polymer with an unsaturated monomer, particularly a copolymer of acrylamide and sodium-2-acrylamido-2-methylpropanesulfonate, is added to an aqueous gelatin composition at a point immediately before any point which requires a high viscosity after and a low viscosity before the addition.

Fast-acting viscosity enhancers for gelatin solutions

The present invention is an edge blade (20) attached to an edge guide (12) for removing an edge of a falling curtain (10). The edge of the falling curtain is intercepted by the edge blade (20) and is vacuumed away by a vacuum tube (21) disposed near the edge blade. The present invention provides a uniform coated edge with maximum coating speeds at the edge being equal to maximum speed possible for the coating system far from the edge.

Edge removal apparatus for curtain coating

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.

Edge guide lubricating fluid delivery apparatus

The present invention is a method determining where to add hardener in a multilayer coating pack on a web fed through a coating station. The process includes determining the frequency and amplitude of the process noise associated with the coating station, determining the growth factor as a function of frequency on the incline surface and repeating these two steps for each of the layers in the coating pack. The plurality of growth factors obtained as a function of frequency is converted into a plurality of wave amplification versus frequency. After the plurality of wave amplitudes versus frequency is determined, one then selects from this plurality the one which is below a predetermined value in order to reduce coating cross streaks.

Minimization of slide instabilities by variations in layer placement,

The present invention is a method and apparatus for use on a curtain coating apparatus. In a curtain coater, edge guides (12) guide the free falling curtain from the hopper lip to the substrate to be coated. Lubricating liquid (15) is introduced near the hopper lip from the top of the edge guide (12). The present invention is a method and apparatus for introducing lubricating liquid (15) as close to the hopper lip as possible while avoiding any turbulence in the flow of the lubricating liquid (15).

Curtain coating method and apparatus

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.

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Rochester, NY, United States of America

James E Conroy