Claims
- 1. Method for transferring a moving web from a creping blade in a creping blade holder to a second location comprising:stabilizing the moving web on a creping blade foil having a top surface, a front edge, and a back edge, the creping blade foil being located beneath the moving web with the front edge touching or in close proximity to the creping blade or the creping blade holder; directing the moving web towards one or more airfoils located between the creping blade foil and the second location, at least one of the airfoils having a bottom, a top, a nose, and a tail, the bottom being essentially flat, the nose being a curved surface attached to the bottom and the top, the top being another curved surface extending from the nose to the tail meeting with the bottom at an edge; and stabilizing the moving web on the bottom of the airfoils.
- 2. The method of claim 1 wherein the moving web is directed substantially tangent to the top surface of the creping blade foil leaving the creping blade foil at the back edge.
- 3. The method of claim 1, wherein a point where the bottom surface of the airfoil joins the nose is located tangent to the top surface of the creping blade foil, the nose of the airfoil is positioned to leave a span from about 4 inches to about 12 inches between the nose of the airfoil and the back edge of the creping blade foil, and the wrap angle of the moving web on the nose of the airfoil is from about 5 to about 25 degrees.
- 4. The method of claim 1 wherein the creping blade airfoil is attached to a doctor beam and an air shower is located on the doctor beam directing the moving web away from the creping blade foil during a web break.
- 5. The method of claim 1 wherein more than one airfoil is placed between the creping blade foil and the second location above the moving web intermittently stabilizing the moving web.
- 6. The method of claim 1 wherein the airfoil is bowed in the cross-machine direction spreading the web.
- 7. A method for transferring a moving web from a creping blade in a creping blade holder to a rotating roll comprising:stabilizing the moving web on a creping blade foil having a top surface, a front edge, and a back edge, the creping blade foil being located beneath the moving web with the front edge touching or in close proximity to the creping blade or the creping blade holder; stabilizing the moving web on at least one airfoil located between the creping blade foil and a roll foil, the roll foil having an internal volume, a back surface, and a gap in the back surface in fluid communication with the internal volume connected to a source of vacuum; the placement of the roll foil defining a region bounded by the rotating roll on a first side, the back surface on a second side, and the web on a third side; and extracting from the region into the internal volume of the roll foil by vacuum through the gap at least a portion of the boundary layer air traveling with the rotating roll whereby the moving web is transferred to the rotating roll with minimal disturbance.
- 8. The method of claim 7 wherein the roll foil has a planer top surface, and the airfoil directs the moving web to run adjacent to the top surface stabilizing the moving web on the roll foil prior to transfer to the rotating roll.
- 9. The method of claim 8 wherein the roll foil has a deflector protruding partially into the moving web attached to the roll foil where the top surface meets a front surface, and the deflector reduces the amount of boundary layer between the moving web and the top surface.
- 10. The method of claim 7 wherein the region is at a pressure less than atmospheric.
- 11. The method of claim 7 wherein a boundary layer reduction member is attached to the back surface defining a fourth side of the region, and the boundary layer reduction member reduces the amount of boundary layer air traveling with the rotating roll.
- 12. The method of claim 11 wherein the boundary layer reduction member comprises a wiper either touching the rotating roll or in close proximity to the rotating roll.
- 13. The method of claim 11 wherein the boundary reduction member comprises an air shower blowing against the rotating roll in a direction opposing the rotation.
- 14. The method of claim 13 wherein the air shower is a drilled pipe.
- 15. The method of claim 13 wherein the air shower is a coanda effect nozzle.
- 16. The method of claim 1 wherein the roll foil has at least one opening located in a front surface in fluid communication with the internal volume, and at least a portion of the boundary layer of air traveling with the moving web is extracted through the opening.
- 17. The method of claim 16 wherein at least a portion of the opening is located within the thickness of the boundary layer of air traveling with the moving web.
- 18. The method of claim 16 wherein the airflow's entering the gap and the opening can be adjusted by a movable plate that changes the size of the opening.
- 19. The method of claim 1 wherein the airfoil has a bottom, a top, a nose, and a tail; the bottom being essentially flat, the nose being a curved surface attached to the bottom and top, the top being another curved surface extending from the nose to the tail meeting with the bottom at an edge.
- 20. The method of claim 1 wherein two or more airfoils are placed between the creping blade foil and the roll foil above the moving web intermittently stabilizing the moving web.
- 21. The method of claim 1 wherein the airfoil is bowed in the cross-machine direction to spread the web.
- 22. The method of claim 1 wherein the moving web is directed substantially tangent to the top surface of the creping blade foil leaving the creping blade foil at the back edge.
- 23. The method of claim 1 wherein the airfoil is located from about 4 inches to about 12 inches from the back edge of the creping blade foil.
Parent Case Info
This application is a divisional of application Ser. No. 09/615,150 now U.S. Pat No. 6,328,852 entitled METHOD AND APPARATUS FOR IMPROVING STABILITY OF MOVING WEBS and filed in the U.S. Patent and Trademark Office on Jul. 13, 2000, which claims priority from U.S. Provisional Application No. 60/150,442, filed on Aug. 24, 1999. The entirety of application Ser. No. 09/615,150 is hereby incorporated by reference.
US Referenced Citations (9)
Provisional Applications (1)
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Number |
Date |
Country |
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60/150442 |
Aug 1999 |
US |