Curtain coating method and apparatus
AssigneeEastman Kodak Company
InventorThomas C. Reiter
Life of this patent
Estimating the term…
Abstract
Method and apparatus for applying one or a plurality of superimposed layers of a photographic coating composition by the curtain coating method onto a moving support. The spacing between the edge guides, used to maintain the width of a curtain throughout its free fall from the coating hopper to the impingement line on the support, is arranged to coat less than the width of the support so as to provide an uncoated margin on the support. The curtain fluids are extracted from the edge region of the falling curtain by connecting a suction device to the edge guides near the point of impingement of the falling curtain, thus substantially reducing the thickness of the curtain at its edge region and thereby reducing the thickness of the coated edges.
Claims25
A method of curtain coating a support, with at least one layer of a liquid coating composition, comprising the steps of:
- (a) moving the support along a path through a coating zone;
- (b) forming a plurality of flowing layers of coating liquids to form a composite layer;
- (c) forming a free falling vertical curtain from said composite layer within said coating zone which extends transversely of said path and impinges on said moving support;
- (d) laterally guiding said falling curtain by edge guides arranged to coat less than the width of said support;
- (e) maintaining said falling curtain in wetting contact with said edge guides by distributing flushing liquid from said edge guides contiguous with said falling curtain;
- and
- (f) extracting liquids from the edge of said falling curtain by a vacuum source connected to said edge guide near the point of impingement of said falling curtain.
A method according to claim 2 wherein the edge region of the coating forms a distinct layered profile of each coated layer which can be dried at the same point in the drier as the coating.
Apparatus for curtain coating a support by depositing a plurality of coating liquids onto a moving support, comprising:
- (a) conveying means including a coating roll for moving said support along a path through a coating zone;
- (b) hopper means for forming a plurality of flowing layers of coating liquids to form a composite free falling curtain which extends transversely of said path and impinges on said moving support;
- (c) edge guide means, spaced apart a distance to produce a coating less than the width of said support, for laterally guiding said falling curtain;
- (d) flushing means for issuing liquid from said edge guide to maintain wetting contact with said falling curtain;
- and
- (e) suction means for extracting liquid from the edge region of said falling curtain by a suction device connected to said edge guide near the point of impingement of said falling curtain.
Dependencies are inferred from the claim text.