Abstract: A fountain applicator for applying coating liquid onto a web of paper carried past the applicator, has a coating liquid flow path that includes a curved surface along which a sheet of the coating liquid is flowed to subject the sheet to centrifugal force to cause air entrained in the coating liquid to move away from one side of the sheet that is toward the curved surface, so that the one side is relatively free of entrained air. After being flowed along the curved surface, the sheet of coating liquid is directed toward the web in a free standing jet curtain of coating liquid, to contact the web surface primarily with the one relatively air-free side of the coating liquid sheet to decrease the occurrence of skip coating on the web surface, especially when the web is traveling past the applicator at high speeds. The coating is applied in excess onto the web surface and is metered and leveled to a desired coat weight by a downstream doctor.

Abstract: A method and apparatus for applying coating liquid to a web of paper traveling over a web supporting surface at speeds of 3,000 or more feet per minute to produce a coated web free of streaking and other imperfections includes the steps and structural elements for distributing coating liquid onto the supported web through a limited application zone within a short dwell time of the liquid on the web, the web moving through the application zone at a speed that is sufficiently high to create turbulence in the coating liquid being applied to the web, doctoring the coating liquid on the web by biasing a primary doctor against the coated web at the rear edge of the application zone so as to form a layer of coating liquid on the web as the web leaves the application zone, the turbulence in the coating liquid causing machine direction streaks in the layer of the coating liquid as the web leaves the application zone; and, at a location downstream and isolated from the application zone, performing a successive doctorin

Abstract: A method of and apparatus for applying coating liquid to a web of paper traveling over a web supporting surface at speeds of 3,000, 4,000 and more feet per minute to produce a coated web free of streaking and other imperfections comprises apparatus for and the sequential steps of distributing coating liquid in a turbulent state over the supported web through a limited application zone within a very short dwell time of the turbulent liquid on the web; subjecting the coating liquid on the supported web to an initial doctoring by means of a primary doctor blade biased under pressure against the coated web at the rear edge of the application zone to form on the web downstream from the zone a relatively quiescent layer of coating liquid having a wet film thickness sufficiently in excess of the final wet film thickness to accommodate a subsequent final wet film doctoring of the coating liquid on the web; and, at a location downstream and isolated from the application zone, subjecting the relatively quiescent layer

Abstract: Apparatus for applying coating liquid to a web of paper traveling over a web supporting surface at speeds of 3,000 or more feet per minute to produce a coated web free of streaking and other imperfections includes the structural elements for distributing coating liquid onto the supported web through a limited application zone within a short dwell time of the liquid on the web, the web moving through the application zone at a speed that is sufficiently high to create turbulence in the coating liquid being applied to the web, doctoring the coating liquid on the web by biasing a primary doctor against the coated web at the rear edge of the application zone so as to form a layer of coating liquid on the web as the web leaves the application zone, the turbulence in the coating liquid causing machine direction streaks in the layer of the coating liquid as the web leaves the application zone; and, at a location downstream and isolated from the application zone, performing a successive doctoring of excess coating liq

Abstract: A method for coating a web with a coating material by applying a metered coating material onto the web and smoothing the applied coating material evenly onto the web with a flexible predoctoring blade. The coating material is applied to the web by the predoctoring blade in the form of a high velocity laminar flow in advance of the predoctoring blade. The coating mix is fed to a stem part of the flexible blade via an exit channel having a narrow opening. The loading of the flexible blade, acting as a smoothing device, is controlled in a cross direction of the web in order to control the cross directional profile of the applied coating web. The feed velocity of the laminar flow is at least one small m/sec.

Abstract: A fountain applicator for applying coating liquid onto a web of paper carried past the applicator, has a coating liquid flow path that includes a curved surface along which a sheet of the coating liquid is flowed to subject the sheet to centrifugal force to cause air entrained in the coating liquid to move away from one side of the sheet that is toward the curved surface, so that the one side is relatively free of entrained air. After being flowed along the curved surface, the sheet of coating liquid is directed toward the web in a free standing jet curtain of coating liquid, to contact the web surface primarily with the one relatively air-free side of the coating liquid sheet to decrease the occurrence of skip coating on the web surface, especially when the web is traveling past the applicator at high speeds. The coating is applied in excess onto the web surface and is metered and leveled to a desired coat weight by a downstream doctor.

Abstract: A gas/air or bubble separator is disclosed, particularly for use with supplying air/gas or bubble free coating liquid to a paper coater. The separator includes three cast elements containing three formed chambers, a distribution chamber at the top of the device which supplies incoming liquid to a plurality of separators which operate on the vortex principle, a liquid collection chamber for collecting the essentially or substantially air/gas or bubble free liquid at the bottom of the device, and an air/gas bubble collection chamber above the vortex separators for collecting the gas/air or bubble containing liquid. These chambers are of cast construction and made of stainless steel so that no weld need be used. The device has essentially inline flow for the bulk of the liquid from inlet to outlet and clean streamline design with no dead spaces to prevent accumulations, build ups and problems associated with the same.

Abstract: A fountain applicator for applying coating liquid onto a web of paper carried past the applicator, has a coating liquid flow path that includes a curved surface along which a sheet of the coating liquid is flowed to subject the sheet to centrifugal force to cause air entrained in the coating liquid to move away from one side of the sheet that is toward the curved surface, so that the one side is relatively free of entrained air. After being flowed along the curved surface, the sheet of coating liquid is directed toward the web in a free standing jet curtain of coating liquid, to contact the web surface primarily with the one relatively air-free side of the coating liquid sheet to decrease the occurrence of skip coating on the web surface, especially when the web is traveling past the applicator at high speeds. The coating is applied in excess onto the web surface and is metered and leveled to a desired coat weight by a downstream doctor.

Abstract: A method of and apparatus for applying coating liquid to a web of paper traveling over a web supporting surface at speeds of 3,000, 4,000 and more feet per minute to produce a coated web free of streaking and other imperfections comprises apparatus for and the sequential steps of distributing coating liquid in a turbulent state over the supported web through a limited application zone within a very short dwell time of the turbulent liquid on the web; subjecting the coating liquid on the supported web to an initial doctoring by means of a primary doctor blade biased under pressure against the coated web at the rear edge of the application zone to form on the web downstream from the zone a relatively quiescent layer of coating liquid having a wet film thickness sufficiently in excess of the final wet film thickness to accommodate a subsequent final wet film doctoring of the coating liquid on the web; and, a a location downstream and isolated from the application zone, subjecting the relatively quiescent layer o

Abstract: A filled supercalender roll is characterized by a plurality of resin impregnated discs that are carried side-by-side on a shaft and form a homogeneous roll body. To make the supercalender roll, a web of woven or nonwoven fibrous material is immersed in and carried through a vat of thermosetting resin to saturate the web with the resin. The resin saturated web is then transported through an oven to partially cure the resin to the B stage, after which the web is cut into a plurality of the discs. The discs are placed side-by-side on the shaft and a collapsible oven is assembled around the discs. The discs are then axially compressed while being heated within the oven to fully cure the resin to the C stage, during which time the collapsible oven decreases in length in accordance with a decrease in the axial length of the axially compressed discs on the shaft as the resin cures.

Abstract: A coater for applying liquid coating material onto a paper web carried across an upstream dip roll applicator that applies an excess layer of coating onto the surface of the web, is cahracterized by an improved downstream doctor assembly for metering and leveling the coating of the web. The doctor assembly includes a doctor blade having a top extended agianst and across the web, and a shear plate just upstream of the blade. The shear plate has a surface facing toward but spaced from the web and a ramp on the surface extending toward the web. As the coating layer on the web contacts the doctor blade, excess coating removed from the web by the blade bounces back off of the blade, flows across the shear plate surface and is deflected by the ramp against the web to rewet the excess coating layer on the web before it reaches the blade.

Abstract: An improved doctor blade, for use at a downstream end of a pressurized coating material application zone of a paper coater, has a tip portion of a limited length and first thickness and a major body portion of a second and increased thickness. The increased thickness of the major body portion enables the doctor blade to resist flexure caused by variations in pressure of the coating material in the zone, so that the blade tip more uniformly meters and levels coating on a paper web. Also contemplated is an arrangement for clamping the blade at the downstream end of the application zone, in a manner to minimize flexure of the blade in response to variations in pressure of the coating material in the zone.

Abstract: An improved paper coating applicator has a body portion defined by forward and rearward relatively movable walls defining a chamber therebetween with an elongate opening thereto positionable generally below, adjacent to and transversely of a paper web, the chamber receiving coating liquid and directing the same generally upwardly through the opening and onto the web. According to one aspect of the improvement, the chamber and a distribution header for introducing coating material therein are of a design enhancing a very uniform application of coating material onto the web. In another aspect, a unique seal structure provides a secure, fluid tight connection between the front and rear walls.

Abstract: A method and apparatus for applying a film of liquid pigmented coating material to a moving web of paper at, and between, a low limit of two pounds per ream and a high limit of fifteen pounds per ream. The method and apparatus utilize a reservoir of liquid coating material established between a forward liquid coating material seal and a rearward pneumatically loaded and clamped doctor blade spaced a small distance of a few inches or less from the liquid seal. The reservoir is pressurized in the range of 7 to 150 inches of water so that the coating material is applied under pressure to the moving web and then almost instantaneously wiped by the doctor blade. The reservoir is formed by two relatively movable, sealed members which may be opened for easy cleaning, and may have one or more internal coating material distribution headers at its end opposite the web to uniformly distribute the coating material.

Abstract: An improved edge seal assembly for an applicator for applying a coating liquid to a moving web of paper, wherein the applicator is of the type having a chamber for receiving the coating liquid and an elongate opening thereto for directing the liquid onto the web, the opening being formed between a front wall of the chamber and a doctor blade extending from the rear side of the opening to against the web, is characterized by a seal element sealed with the front wall and doctor blade in an end space therebetween, and a deckle beneath the seal element for closing off a selected portion of the side end of the opening. The seal element and the deckle are slidingly interconnected and can be independently adjusted laterally with respect to the opening.

Abstract: A gauge for measuring the size of a nip between a pair of rolls is characterized by a cylindrical carrier within which a platform is mounted for pivotal movement about the carrier axis. A transducer is carried on the platform, and a quasi U-shaped rod or probe is pivotally connected at one end with the platform, extends along a medial portion thereof outwardly of the carrier and presses against the transducer at an opposite end. The probe is pivotally urged in a direction outwardly of the carrier, and in use of the gauge the medial portion of the probe is moved into the nip between the rolls and against the rolls and the carrier into contact with the rolls, whereby the transducer provides a readout in accordance with the radii of the rolls at the point of contact by the probe.

Abstract: To measure the opacity of sheet material, such as paper, a beam of light is directed against the material and the intensity of any light passing through the material is sensed and converted to a visual readout. A plurality of opacity measurements are made at different areas on the sheet material and, when a selected number of measurements have been made, a readout of the average value of the measurements is generated. The particular technique enables a large number of opacity measurements to be quickly and conveniently made and averaged, and is considerably less complicated and time consuming than opacity measurements which are conventionally made as a function of contrast ratios.

Abstract: An applicator for applying a film of coating material on a web of moving paper carried through an application zone and having a coater blade for doctoring the material on the web as it exits the zone, includes an internal leveling blade within the application zone. The leveling blade divides the application zone into leading and lagging coating material application chambers, and levels the material applied on the web in the leading chamber as the web moves into the lagging chamber. The leveling blade produces a pressure and shear point of coating material to paper so as to cause coating penetration and filling of voids and valleys in the paper, and the coater blade then levels and meters the film of fresh coating applied on the web in the lagging chamber to complete the process.

Abstract: An improved edge or end dam assembly for an applicator for applying a coating liquid to a web of moving paper carried on a backing roll, the applicator being of the type having a chamber for receiving the coating liquid and an opening therein for directing the liquid onto the web, the opening being formed between a front wall of the chamber and a doctor blade extending from the rear of the opening to against the web, is characterized by a seal element sealed with the front wall and doctor blade in an end space therebetween and extending toward and closely adjacent but spaced from the web. The face of the seal element adjacent the paper web has a plurality of grooves extending generally parallel to the direction of movement of the web, so that coating material which seeps past the seal element and beyond the edge dam assembly enters the grooves and is moved by the web toward the doctor blade for deposit on the web.

Abstract: A method and apparatus are disclosed for use with a paper coater located on a backing roll of, for example, a papermaking machine. In the method, apparatus in the form of a hinged bridge is used to collect excess coating liquid from a remote doctor blade or a first coater having such blade and supply the same to a second coater. The bridge may be mounted to the doctor blade or the first coater so that it can be placed in a bridging position accommodating various angles of the doctor blade, or in a second stored position wherein it will not interfere with the operation of either coater or the doctor blade.