A SHORT DWELL COATER APPARATUS

• Main Author: BUSKER, LEROY H
• Format: Patent
• Language: English; French
• Published: 16.01.2001
• Edition: 6
• Subjects: APPARATUS FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; IMPREGNATING OR COATING OF PAPER; PAPER NOT OTHERWISE PROVIDED FOR; PAPER-MAKING; PERFORMING OPERATIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; PRODUCTION OF CELLULOSE; PULP COMPOSITIONS; SPRAYING OR ATOMISING IN GENERAL; TEXTILES; TRANSPORTING; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G

A short dwell coater apparatus (10) is disclosed for applying coating material to a web (W) supported by a backing member (12). The apparatus (10) includes a housing (14) which defines an application zone (16) having an upstream and a downstream end (18, 20). The zone (16) extends in a cross-machine direction (CD) across the web (W) and is connected to a source of the coating material (22) such that the coating material is applied to the web (W) during movement of the web past the application zone (16). An elongate pipe (24) is disposed within the application zone (16) and extends in a cross-machine direction (CD) across the application zone (16). The pipe (24) defines at least one orifice (26) for the passage therethrough of the coating material. The pipe (24) is connected to the source of coating material (22) such that the coating material flows through the pipe (24) and through the orifice (26) for supplying coating material to the application zone (16). A vane (30) is rigidly secured to the pipe (24) and extends in a machine direction (MD) away from the pipe (24) towards the web (W) such that coating material supplied through the orifice (26) generates a hydrodynamic wedge (32) between the vane (30) and the web (W) for reducing entrained air vortices within the application zone (16). A metering blade (34) is disposed adjacent to the downstream end (20) of the application zone (16) for metering exccess coating from the web (W).