Abstract:
Pre-treatment tunnel and method of preparing extrusions or section bars for being coated, wherein each workpiece is caused to move along a pre-treatment path and each treatment liquid is poured from above onto each workpiece so as to spread liquid onto the entire external surface of each workpiece with no solution of continuity.
Abstract:
A method of curtain coating, the curtain being formed from at least one layer of coating solution having a composite density &rgr; (kgm−3) and a total volumetric flow rate per unit curtain width Q (m2s−1), the curtain being allowed to free fall a distance h (m), at a velocity U (ms−1), onto a continuously moving substrate having a velocity S (ms−1) with an application angle of &thgr; between the horizontal and tangent to the substrate at the point of impingement, the dynamic surface tension at the rear of the falling curtain being &sgr; (mNm−1), the aforementioned variable parameters being controlled so as to prevent recirculation.
Abstract:
A method for reducing coating defects caused by strikethrough when simultaneously slide coating a first fluid layer, a second fluid layer, and a third fluid layer. The method includes preparing the first, second, and third fluids such that the first solute is incompatible with the second and third solutes and such that the first fluid minimizes strikethrough of at least one of the second and third fluids to a slide surface when the first fluid is positioned between the slide surface and the second and third fluids. The present invention is useful in preparing imaging, data storage, and other media.
Abstract:
The curtain coating apparatus of the invention comprises a sliding face on which a coating solution flows down, a coating width regulating plate which is located on each of both sides of the sliding face and regulates the width of the flow of the coating solution, and an edge guide which is connected to the width regulating plate, and keeps both side edges of free falling stream of the coating solution from the sliding face, wherein a contact angle of water with the coating width regulating plate is greater than a contact angle of water with the edge guide, and the apparatus has solved problems of streaks and uneven thickness at side end portions of a free falling film caused by contraction and teapot phenomenon (residence), by changing wett properties at a coating width regulating plate and an edge guide.
Abstract:
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.
Abstract:
A curtain coating method of coating a continuously travelling web with at least two kinds of coating solutions superposed upon one another in layers includes the steps of supplying said coating solutions to flow as a free falling curtain and impinging the coating solutions on the web, in which differences in gelatin concentration and viscosity between a coating solution for a lowest layer and a coating solution for an adjacent layer are adjusted to 0-2 weight percent and 0-20 cp respectively. Furthermore, a curtain coating apparatus for coating a web with a coating solution includes a hopper with a slide plane on which the coating solution flows and with a hopper lip from where the coating solution begins to freely fall down as a free falling curtain, and at least a pair of outlets which are each disposed in a position along the edge part of the free falling curtain and situated in a fixed distance down from the hopper lip, in which the auxiliary solutions are introduced from the width directions so as to maintain the curtain in the width direction thereof.
Abstract:
A method for reducing coating defects caused by strikethrough when simultaneously slide coating a first fluid layer, a second fluid layer, and a third fluid layer. The method includes preparing the first, second, and third fluids such that the first solute is incompatible with the second and third solutes and such that the first fluid minimizes strikethrough of at least one of the second and third fluids to a slide surface when the first fluid is positioned between the slide surface and the second and third fluids. The present invention is useful in preparing imaging, data storage, and other media.
Abstract:
A method for reducing coating defects caused by strikethrough when simultaneously slide coating a first fluid layer, a second fluid layer, and a third fluid layer. The method includes preparing the first, second, and third fluids such that the first solute is incompatible with the second and third solutes and such that the first fluid minimizes strikethrough of at least one of the second and third fluids to a slide surface when the first fluid is positioned between the slide surface and the second and third fluids. The present invention is useful in preparing imaging, data storage, and other media.
Abstract:
This invention is related to a die set and method for the production of multiple stripes with two different materials A and B adjacent to each other. The special feature of this invention is that a specially designed shim is inserted between two pieces of coating dies. When liquids A and B enter the two sides of the die set separately, B liquid will flow through the distribution passages in the shim to form multiple stripes and then contact stripes of A liquid in the same slot section. The multiple stripes of repeated coating liquids that consists of ABAB patterns will be generated once the multiple stripes are coated and dried on the substrate.
Abstract:
In the method for curtain coating a moving support with any kind of coating solution, lateral flow is supplied to the guided curtain on both sides transversely to the length of the curtain and in parallel to the front wall of the lateral guides. The supply of the liquid film on the lateral guide is effected in such a manner that its surface velocity is equal to the falling velocity of the curtain at any point along the lateral guide. The device implementing the method features a porous plate which is arranged between the liquid supply and the curtain side. This ensures a constant coating without any disturbances due to marginal influences.