摘要:
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 liquid on the supported web by biasing a final doctor blade against the coated web to remove excess coating from the web and to level and smooth the coating retained on the web to a final wet film thickness and smoothness.
摘要:
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 of excess coating liquid on the supported web to a final docttoring by means of a final doctor blade biased under pressure against the coated web to remove the excess coating from the web and to level and smooth the coating retained on the web to final wet film thickness and smoothness.
摘要:
A paper coating system is characterized by an upstream dip roll applicator that applies an excess layer of liquid coating material onto a surface of a paper web, and an improved downstream doctor assembly for metering and leveling the coating on the web. The doctor assembly includes a doctor blade having a tip extended against and across the web and a shear plate, upstream of the blade, having a surfaces extending across and defining a gap with the web. An elongate chamber defined between the shear plate and blade extends across the web, and excess coating removed from the web by the blade flows into the chamber. Coating is drained from and uniformly along a lower end of the chamber at a rate to maintain an eddy current pool of coating in an upper end of the chamber immediately upstream of the blade/web nip, but to prevent formation of a liquid seal in the gap. The eddy current pool of coating rewets the excess coating on the web just prior to the blade to level and smooth streaky film split patterns that occur from dip roll application, so the blade doctors the coating very uniformly and a very uniform coating is on the finished paper sheet. To further improve uniformity, the shear plate is adjusted so that the gap is sufficiently small to prevent any outflowing coating from spattering onto the incoming web, yet large enough to prevent formation of a liquid seal in the gap.
摘要:
An assembly having at least three coaters or separate doctor or blade units, all arranged at a single backing roll coating station is provided. At least two of the coater or blade units can be movably positioned for easy operation and servicing of all three units. Additionally, one or more of the coater units may have doctors or blades, and the coater units with blades or blade unit may each be angularly positioned through a range of blade angles to optimize coating operations.
摘要:
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 doctoring of excess coating liquid on the supported web by biasing a final doctor blade against the coated web to remove excess coating from the web and to level and smooth the coating retained on the web to a final wet film thickness and smoothness.
摘要:
A faucet handle connector that securely attaches a grip of a faucet handle to a valve apparatus for regulating the flow rate and/or temperature of water through a faucet spout. The faucet handle connector provides a structure for convenient attachment of the faucet handle to the valve apparatus. In addition, the faucet handle connector attaches the faucet handle to the valve apparatus in a manner that conceals the faucet handle connector from a user to improve the aesthetic characteristics of the faucet and to reduce the number of parts required for assembly. Thus, the faucet handle connector attaches the faucet handle to the valve apparatus without the use of a screw or any other observable fastener, and a separate cover or similar structure is not required to hide the connector.
摘要:
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 of excess coating liquid on the supported web to a final doctoring by means of a final doctor blade biased under pressure against the coated web to remove the excess coating from the web and to level and smooth the coating retained on the web to final wet film thickness and smoothness. The method and apparatus of the present invention produces essentially a constant paper smoothness in relation to web speed at which it was coated and subsequently supercalandered, i.e., smoothness does not decrease at higher web speeds, and produces higher gloss with less decline in gloss at higher web speeds.
摘要:
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.
摘要:
A paper coating system is characterized by an upstream dip roll applicator that applies an excess layer of liquid coating material onto a surface of a paper web, and an improved downstream doctor assembly for metering and leveling the coating on the web. The doctor assembly includes a doctor blade having a tip extended against and across the web and a shear plate, upstream of the blade, having a surface extending across and defining a gap with the web. An elongate chamber defined between the shear plate and blade extends across the web, and excess coating removed from the web by the blade flows into the chamber. Coating is drained from and uniformly along a lower end of the chamber at a rate to maintain an eddy current pool of coating in an upper end of the chamber immediately upstream of the blade/web nip, but to prevent formation of a liquid seal in the gap. The eddy current pool of coating rewets the excess coating on the web just prior to the blade to level and smooth streaky film split patterns that occur from dip roll application, so the blade doctors the coating very uniformly and a very uniform coating is on the finished paper sheet. To further improve uniformity, the shear plate is adjusted so that the gap is sufficiently small to prevent any outflowing coating from spattering onto the incoming web, yet large enough to prevent formation of a liquid seal in the gap.