Abstract: A coater head for contacting a liquid coating material with a traveling web of paper or fabric. The coater head includes at least two chambers and an extended outflow bubble to increase the zone of contact between coating liquid and the traveling web. Improved, coating quality also results from controlled flow characteristics through the coater head having a feed zone length-to-depth ratio of four or more.

Abstract: A method and apparatus for applying a uniform coating to a moving paper web by utilizing a coating applicator with regional cross-machine zones from which coating quality or excess coating can be monitored and analyzed. As the coating conditions vary between regional zones, upstream liquid coating flow parameters can be varied for a particular region to render uniform coating profiles across the entire machine-direction of the web.

Abstract: A soft nip calender employing a compliant roll constructed of circumferentially superpositioned layers of compliant material which are progressively less compliant as the layers approach an underlying steel roll.

Abstract: A short dwell coater and film applicator coating has an application chamber between an inlet overflow baffle plate and a final metering element. An adjustable wedge is spaced in the machine direction from a fixed wedge to define a gap which serves as a coating extraction port. A cylindrical rod is positioned in the extraction port which is about 3/8th to about two inches in diameter and is driven to rotate at a rate of between one and one-hundred rpm. The rod serves to extract air and coating from the application chamber. Alternatively, an adjustable plate may be positioned to obstruct an opening leading to the extraction port.

Abstract: A method and apparatus for coating a traveling paper web includes a coating applicator disposed in movably-controlled spaced adjacency with the paper web, which is supported on a rotating backing roll. The coating applicator permits a controlled introduction of a fresh portion of an aqueous slurry of coating material which is mixed with a recirculated portion of coating material in a controlled manner to prevent the formation of large vortices within the coating applicator. The coating material flows successively through mixing, convergent, and recirculation channels, all of which are defined on one side thereof by a distinct surface of a flow stabilizer which is positioned centrally in a cavity in the coating apparatus.

Abstract: An applicator head is positioned beneath a backing roll and has a housing divided into three sections. A first coating pond is defined between an overflow barrier and a first wall. A converging plate extends between the first wall and a second wall, and converges toward the substrate, and a second pond is defined between the plate and an end wall. Coating is introduced to both ponds. A low pressure cavity is defined beneath the converging plate and between the first wall and the second wall. The cavity opens to the second pond, and draws air and excess coating from the second pond. The substrate is prewetted as it passes through the first pond, and coating deprived of entrained air is applied to the substrate in the second pond. Coat weight uniformity and increased machine speeds are thus achievable.

Abstract: An applicator head is positioned beneath a backing roll over which a substrate can be drawn. The applicator head has a housing which contains a pond of coating material between an up machine overflow lip and a down machine extraction plate or premetering plate. Coating material at a relatively low velocity flows into the pond adjacent to the overflow lip. The premetering plate extends radially from the coating inlet to a position proximate to and converging with the backing roll, where it premeters the amount of coating applied to the substrate. The premetering plate preferably has a plurality of holes through which coating and air are drawn. A metering element is spaced downstream of the premetering plate, and a low pressure area is constructed therebetween. Air and coating are drawn from the low pressure area through a valve, and the pressure thereby controlled.

Abstract: Air entrained within the pond of a coating applicator is influenced toward a designated region for removal. The region is formed by a recessed air collector which sets up a high-recirculation, low-pressure zone within the pond. Entrained air bubbles migrate to the collector. The collected air and excess coating is drawn out of the collector cavity by a plurality of perforations which discharge to a collection cavity at a lower pressure or partial vacuum. The collector structure may be employed in various coater/size press configurations.

Abstract: A uniform film of coating is delivered onto a substrate at high speed by a film applicator, such as a coater apparatus for a papermaking machine, which has a static converging wedge, an adjustable converging wedge, and an extraction channel located between the two wedges. As a unit, the film applicator minimizes the hydrodynamic flow instabilities, as well as reduces flow variations associated with a nonuniform feed and a dynamic contact line. The film applicator also removes entrained air and excess coating from the application zone in order to improve the flow stability and machine runnability.