Apparatus and method for stabilizing a moving web

Abstract

An apparatus for causing an air movement in a cross-machine direction and substantially parallel with a stabilizer surface adjacent a moving web, the apparatus positioned adjacent the stabilizer at or outside a sheet edge of the stabilizer, the apparatus directing a fluid movement in a direction moving away from the side edges of the moving web to stabilize the edges of the web.

1 . A web stabilizer comprising:
 a surface adjacent a moving web, wherein the surface includes a sheet edge region adjacent each side edge of the web, and   a fluid moving or direction device mounted to or near the sheet edge region, wherein the fluid moving device causes fluid to move adjacent the sheet edge region in a direction moving away from the side edge of the web aligned with the sheet region.   
     
     
         2 . The web stabilizer in  claim 1  wherein a gap between the fluid moving or direction device and the planar surface, and the fluid moves through the gap. 
     
     
         3 . The web stabilizer in  claim 1  wherein the fluid moving or direction device has a passage for positively or negatively pressurized air, e.g., compressed air or a vacuum, and the moving device has at least one orifice arranged along the sheet region to move the fluid. 
     
     
         4 . The web stabilizer in  claim 3  wherein the orifices are at least one of outlets, holes, slots, and nozzles. 
     
     
         5 . The web stabilizer in  claim 1  wherein the fluid moving or direction device is arranged along at least one of the sheet edge regions. 
     
     
         6 . A method to reduce curl in a side edge of a moving web comprising:
 moving the web along a surface of a stabilizer;   moving air away from a side edge of the web as the web moves along the surface of the stabilizer, and   moving the edge of the web towards the surface of the stabilizer by a force formed by the movement of the air away from the side edge.   
     
     
         7 . The method of  claim 6  wherein the movement of the air includes passing the air between a gap generally parallel to the side edge of the web. 
     
     
         8 . The method of  claim 7  wherein the air passing through the gap flows along the surface of the stabilizer or an air discharge device in accordance with a Coanda Effect. 
     
     
         9 . The method of  claim 6  wherein the air is moved through the gap by a pressure difference generated across the gap by a source of compressed air or a vacuum source. 
     
     
         10 . The method of  claim 6  wherein the air is drawn through gap by a vacuum source. 
     
     
         11 . The method of  claim 7  wherein the gap has a width in a range of 0.001 inch to four inches. 
     
     
         12 . The method of  claim 7  wherein the gap is within twelve inches of the web edge along a horizontal direction. 
     
     
         13 . The method of  claim 6  wherein the air source comprises at least one air outlets, holes, slots, or nozzles. 
     
     
         14 . The method of  claim 7  wherein the gap is continuous along a length of the stabilizer. 
     
     
         15 . The method of  claim 7  wherein the gap comprises a series of openings along a length of the stabilizer. 
     
     
         16 . The method of  claim 6  further comprising adjusting a rate or direction of the moving air based on at least one of a velocity of the web, an amount of curl in the side edge of the web and a composition of the web. 
     
     
         17 . A web stabilizer comprising:
 a surface adjacent a moving web, wherein the surface includes a sheet edge region adjacent each side edge of the web;   a gap forming device mounted to or near the sheet edge region;   a gap adjacent the side edge of the web and formed between the gap forming device and the surface, and   a source of pressurized fluid positioned to force a fluid through the gap in a direction away from the side edge of the web.   
     
     
         18 . The web stabilizer in  claim 17  wherein the source of pressurized fluid is a vacuum drawing air out of the gap. 
     
     
         19 . The web stabilizer in  claim 17  wherein the gap forming device is a bar extending along the side edge of the web. 
     
     
         20 . The web stabilizer in  claim 17  wherein gap is no greater than one inch in a vertical direction.