Eastman-kodak Company

Douglas S Finnicum

Steven J Weinstein

Kenneth J Ruschak

Joseph W Hoff

Robert R Quiel

Edward R Schickler

David A Wakefield

Richard Dean Young

Robert J Deprez

Alain E Gros

H Galen Parker

Daniel J Suter

Solomon T Korokeyi

Felipe M Joos

William J Soules

Robert A Wahlers

Jack Duane Peters

Lawrence J Finucane

Son Minh Le

Christophe Georges Levarlet

Thomas E Story

Kurt S Hardenbrook

Jack A Pegoni

A method of bead coating a liquid composition onto the surface of a moving web is taught which provides uniform coatings over a wider range of operating parameters including new coating windows. In addition, the bead coating method typically demonstrates a reduction in coating sensitivity to vacuum pressure noise below the coating bead. The method comprises the steps of forming a bottom layer on a slide surface of a slide bead coating apparatus with a pseudoplastic liquid composition having a viscosity between 8 and 200 centipoises at a shear rate of 100 sec and a viscosity below 10 centipoises at a shear rate of 100,000 sec ; forming at least one other liquid coating layer above the bottom layer on the slide surface of the slide bead coating apparatus; establishing a coating bead between a lip of the slide bead coating apparatus and the moving web supported on a back-up roller, generating an electrostatic field in an air gap between the coating bead and the moving web just prior to a dynamic wetting line by creating a potential difference across the air gap of between about 300 and about 2000 volts.

Slide bead coating method

A hopper bar having a longitudinal channel formed in the portion of the bar which normally would support a coating lip wherein a wall of the channel is a precision cylindrical locating pin, and has a replaceable hopper lip element, formed to fit within the channel, is provided with a precision round bushing for receiving the locating pin such that upon assembly of the element to the hopper there is no offset significant to the coating process between the slide surface of the hopper bar and the slide surface of the lip element. The lip element may be attached to the hopper wall along the remainder of their mutual length by either bolts or magnets to permit independent longitudinal thermal expansion of the hopper bar and lip element.

Coating hopper having a replaceable hopper lip element

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.

Method and apparatus for curtain coating

The present invention is an improved flywheel for damping vibrations in a coating roll. The improved flywheel has an inner plate and an outer plate and sandwiched between the two plates are alternating rings of a solid body material such as aluminum or steel and conventional vibration damping material. Typically, the flywheel is attached to the coating roll outside of the bearing mounting block. The flywheel is designed such that movement of the inner and outer plates relative to each other works to compress the damping material sandwiched between the two plates. The plates are fastened together so that torsional motion between the plates, alternating rings, and coating roll is prevented. This compression of the damping material results in the absorption and dissipation of vibrational energy of the radial bending of the coating roll.

Flywheel for coating rolls

A method of coating moveable supports at high speeds comprises moving a support along a path through a coating zone; forming two or more layers including a topmost layer of coating liquids to form a liquid coating composition; and applying the liquid coating composition to the moving support wherein the topmost layer of the liquid coating composition is shear thinning.

High speed coating starts using a shear thinning top layer

A method of coating moveable supports at high speeds comprises moving the support along a path through a coating zone, forming two or more layers of coating liquids including an actual top coat layer to form a liquid composition (with a slide hopper coating a plurality of outlets for coating liquids) and applying a starting top most layer of coating liquid, which layer has a lower viscosity than that of the actual top coat layer, to the liquid coating composition either through the first outlet of the hopper or through an x-hopper located between the first outlet and coating zone, applying the coating composition and starting top most layer, and terminating the application of the starting top most layer when the coating operation is at steady state. Apparatus for carrying out this method is also described.

High speed coating starts for multiple layer coatings using a temporary

The invention aims to optimize a given parameter of a process of coating a support with a liquid composition. The device comprises: a) means (9, 10) for varying the parameter according to a predetermined profile; b) first detection means (11) for producing a first density profile for the support (6) across the width of the support, as the parameter varies; c) second detection means (13) for producing a second density profile for the support (6) parallel to the longitudinal axis, as the parameter varies; and d) means (15, 10) for determining a range of values for the said parameter for which the first and second profiles are satisfactory.

Device and method for optimizing a given parameter in a process of

An image processor based system and method are provided for recognizing predefined-types of coating density imperfections in a web. Specific imperfection-types to be analyzed include continuous-type, as well as point-type, anomalies. Continuous-type imperfections are recognized in a moving continuous web through the accumulation and integration of density data on the web passing through a system imaging area. Depending upon the type of imperfection to be imaged, the light source provides either constant illumination or strobed illumination of the moving coated web. For most types of imperfections, transmissive illumination of the web is used, however, for point-type anomalies reflective illumination is possible, particularly if the web is static. A machine vision image processor contains predefined lookup tables which allow adaptive control of web illumination within the imaging area. An integrating sphere is used to provide for uniform web illumination. Corresponding machine vision based imperfection recognition processing routines are also described.

Coating density analyzer and method using image processing

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.

Method and apparatus for adjusting the curtain impingement line in a

A method and apparatus for coating a surface of a continuously moving substrate with a continuously flowing curtain of coating composition comprises transmitting a sound or light wave toward the curtain and detecting the sound or light wave after the transmitting of the sound or light wave. The presence of the curtain is confirmed by either a positive receiving of a reflected sound or light on the smae side of the curtain as the transmitting of the sound or light wave, or a negative receiving of the transmitted sound or light wave on the other side of the curtain. The position of a continuously flowing curtain of coating composition is determined by measuring a time lapse between the time a sound or light wave is transmitted and the time a sound or light wave after reflection from the curtain is received. If the time lapse is outside a predetermined range of a control time period, a signal is generated to indicate that the curtain is defective.

Ultrasonic monitoring of a freely flowing curtain of coating material

Disclosed are apparatus and method for bead coating a web with liquid composition with a pressure differential applied across the bead of composition between the lip of the slide hopper and the web. An enclosure is disposed under and open to the bead. Vacuum is applied to the enclosure by a turbine driven by an AC induction motor. Servo means are provided for regulating the speed of the motor and thereby the pressure differential across the bead. The AC motor and the servo means allow the desired pressure to be maintained without surges and allows the differential pressure to be rapidly changed, as for the passage of a splice in the web through the bead.

Method and apparatus for use in bead coating a web with liquid

Apparatus for curtain coating a web or article includes a coating hopper, a support roller, guide rollers for leading the web to and from the support roller and an enclosure. Air which has been conditioned in respect of temperature, humidity and cleanliness is introduced into an upper region of the enclosure. Air flow controlling means are provided below the region into which the conditioned air is introduced. The flow controlling means serve to control the flow of air downwards so that it is uniform across a horizontal plane within the enclosure and has a speed of about 10 feed per minute in the region of the coating liquids in the curtain, that being a speed which will not cause disturbing effects on the liquids in the curtain. The enclosure prevents random air currents of uncontrolled velocity, temperature and cleanliness impinging on the liquids in the curtain and on the slide, which might otherwise adversely affect the product coating. The change of air and the humidity selected for the incoming air keep the humidity within the enclosure at acceptable levels, the humidity tending to increase by virtue of evaporation of the solvent or vehicle in the coating liquid. The air passes out of the enclosure well below the curtain, in the lowest region of the enclosure. The air in the enclosure is at a temperature approximating to that of the coating liquids. In this way condensation of evaporated solvent or vehicle on equipment above and around the liquid curtain, is avoided.

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Webster, NY, United States of America

Douglas S Finnicum