Claims
- 1. A device for non-contact support of a continuous web that is moving in a downstream direction that comprises:
(a) a body having an operative surface facing the web wherein the operative surface has an upper portion and a lower portion that is downstream from the upper portion and wherein the body defines a slot that is in fluid communication with a source of gas and that has an opening at the upper surface, and wherein the slot has a curved convex surface at the opening on its downstream side; and (b) means for directing a gas from the gas source through the slot so that a jet of gas moves through the opening and toward the lower portion whereby a low pressure field is established as the gas passes from the upper portion to the lower portion thereby maintaining a portion of the moving web at a substantially fixed distance to the operative surface.
- 2. The device of claim 1 wherein the upper portion is vertically spaced from the lower portion.
- 3. The device of claim 1 wherein the upper portion and the lower portion are parallel to each other and the surface connecting the upper portion to the lower portion defines a plane that is perpendicular to the upper portion and lower portion.
- 4. The device of claim 3 wherein the vertical distance between the upper portion to the lower portion is about 100 μm to 1000 about μm.
- 5. The device of claim 1 wherein the surface connecting the upper portion and the lower portion is a concavely curved surface.
- 6. The device of claim 1 wherein the body defines a plenum and the means for directing the gas comprises a pump that pumps gas through the plenum and into the slot.
- 7. The device of claim 1 wherein the gas discharged from the slot at a velocity of about 50 m/s to about 80 m/s.
- 8. The device of claim 1 wherein the gas in air.
- 9. The device of claim 1 wherein the slot comprises an elongated opening with a length that is transverse to the direction of the moving web.
- 10. The device of claim 9 further comprising means for adjusting the width of the opening.
- 11. The device of claim 10 wherein the opening separates the upper portion of the body into an upstream portion and a downstream portion, and wherein the upstream portion is pivotally attached to the body to permit adjustment of the width of the opening.
- 12. The device of claim 9 wherein the opening has a width of about 75 μm to 100 about μm.
- 13. The device of claim 1 wherein at least a portion of the moving web is maintained at a distance of about 400 μm to about 800 μm above the surface of the body.
- 14. The device of claim 1 wherein the web is moving at a speed of about 800 m/min to about 2700 m/min.
- 15. The device of claim 1 wherein the curved convex surface has a radius of curvature of about 1.6 mm to about 10 mm.
- 16. The device of claim 1 wherein the web comprises paper.
- 17. A method of maintaining a continuous web that is moving in a downstream direction and in a prescribed orientation relative to a reference position that comprises the steps of:
(a) positioning a web stabilizer below the moving web wherein the stabilizer comprises body having an operative surface facing the web wherein the operative surface has an upper portion and a lower portion that is downstream from the upper portion and wherein the body defines a slot that is in fluid communication with a source of gas and that has an opening at the upper surface, and wherein the slot has a curved convex surface at the opening on its downstream side; and (b) directing a gas from the gas source through the slot so that a jet of gas moves through the opening and toward the lower portion whereby a low pressure field is established as the gas passes from the upper portion to the lower portion thereby maintaining a portion of the moving web at a substantially fixed distance to the operative surface.
- 18. The method of claim 17 wherein the upper portion is vertically spaced from the lower portion.
- 19. The method of claim 17 wherein the upper portion and the lower portion are parallel to each other and the surface connecting the upper portion to the lower portion defines a plane that is perpendicular to the upper portion and lower portion.
- 20. The method of claim 19 wherein the vertical distance between the upper portion to the lower portion is about 100 μm to 1000 about μm.
- 21. The method of claim 17 wherein the surface connecting the upper portion and the lower portion is a concavely curved surface.
- 22. The method of claim 17 wherein the body defines a plenum and the means for directing the gas comprises a pump that pumps gas through the plenum and into the slot.
- 23. The method of claim 17 wherein the gas discharged from the slot at a velocity of about 50 m/s to about 80 m/s.
- 24. The method of claim 17 wherein the gas in air.
- 25. The method of claim 17 wherein the slot comprises an elongated opening with a length that is transverse to the direction of the moving web.
- 26. The method of claim 25 wherein the body further comprising means for adjusting the width of the opening.
- 27. The method of claim 26 wherein the opening separates the upper portion of the body into an upstream portion and a downstream portion, and wherein the upstream portion is pivotally attached to the body to permit adjustment of the width of the opening.
- 28. The method of claim 25 wherein the opening has a width of about 75 μm to 100 about μm.
- 29. The method of claim 17 wherein at least a portion of the moving web is maintained at a distance of about 400 μm to about 800 μm above the surface of the body.
- 30. The method of claim 17 wherein the web is moving at a speed of about 800 m/min to about 2700 m/min.
- 31. The method of claim 17 wherein the curved convex surface has a radius of curvature of about 1.6 mm to about 10 mm.
- 32. The method of claim 17 wherein the web comprises paper.
- 33. The method of claim 17 wherein the moving web is maintained as a flat profile in both a machine direction and a cross direction.
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application Serial No. 60/345,860 filed on Oct. 24, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60345860 |
Oct 2001 |
US |