Claims
- 1. A web positioning device for use with a gap drying system, the device comprising:
one or more ports positioned in or adjacent at least one platen of the gap drying system, wherein upon generation of a vacuum force through each port, movement of a web of material conveyed through the gap drying system is arrested by drawing a first face of the web of material into contact with a portion of the web positioning device immediately surrounding each port.
- 2. The web positioning device of claim 1 wherein the web of material has a second face opposite its first face, and wherein generation of the vacuum force causes only the first face of the web of material to contact the web positioning device.
- 3. The apparatus of claim 1 wherein each port is an elongate slot located in or adjacent a lower platen of the gap drying system, and each elongate slot is arranged substantially perpendicular to a longitudinal direction of travel of the web of material.
- 4. The apparatus of claim 1 wherein each port is an elongate slot located in a port structure, and each port structure is arranged substantially perpendicular to a longitudinal direction of travel of the web of material.
- 5. The apparatus of claim 1 wherein each port is deckled for accommodating variously sized webs of materials.
- 6. The apparatus of claim 1 wherein a spacing between a top platen of the gap drying system and a second face of the web of material is increased while the vacuum force is generated.
- 7. A method for controlling movement of a portion of a web of material held in tension, the method comprising:
monitoring a longitudinal tension of the web of material; and utilizing one or more gas flow ports located relative a first face of the portion of the web of material to generate a vacuum force, the vacuum force activated as a function of the tension of the web of material.
- 8. The method of claim 7 wherein the vacuum force is activated based upon a predetermined variance in longitudinal tension of the portion of the web of material.
- 9. The method of claim 7 wherein activation of the vacuum force holds the portion of the web of material in a static position.
- 10. The method of claim 7 wherein each gas flow port is in or adjacent a lower platen of a gap drying system, which has an upper condensing platen spaced therefrom, and further comprising:
increasing a distance between the upper condensing platen and the portion of the web of material while the vacuum force is activated.
- 11. The method of claim 7 wherein activation of the vacuum reduces movement of the web of material by drawing the first face of the web of material into contact with a portion of the web positioning device immediately surrounding one of more of the gas flow ports, and wherein activation of the vacuum does not cause contact with a second face of the web of material.
- 12. An improved coating machine for coating a web of material having a first face and an opposite second face, the coating machine including a gap dryer, the improvement comprising:
a web positioning device for activating a vacuum that acts only on the first face of the web of material to arrest movement of the web of material relative to the gap dryer.
- 13. The improvement of claim 12 wherein activation of the vacuum holds the web of material in a fixed position.
- 14. The improvement of claim 12 wherein the web positioning device includes a first vacuum port disposed on only one side of the web of material and relative to the first face of the web of material.
- 15. The apparatus of claim 14 wherein when the first vacuum port is deckled for accommodating variously sized webs of materials.
- 16. The improvement of claim 14, and further comprising a second vacuum port spaced longitudinally along a path of the web of material from the first vacuum port.
- 17. The improvement of claim 14 wherein the port is located in or adjacent at least one platen of the gap dryer.
- 18. The improvement of claim 17 wherein a spacing between two opposed platens of the gap drying system is increased while the vacuum is activated.
- 19. The improvement of claim 14 wherein the first vacuum port is located anywhere along a path of the web of material.
- 20. A gap drying system for drying a wet coating on one face of a web of material moving longitudinally over a web processing path, the gap drying system comprising:
a lower platen disposed in the web processing path; and an upper platen disposed along the web processing path and spaced from the lower platen by a first spacing, wherein upon the occurrence of a specified condition which affects movement of the web of material along the web processing path and between the lower and upper platens, a vacuum force draws the web of material toward the lower platen and the first spacing between the lower platen and the upper platen is increased.
- 21. The gap drying system of claim 20 wherein the specified condition is an upset of the web of material.
- 22. A web coating machine for coating a web of material having first and second faces, the web coating machine comprising:
a tension zone characterized along a web travel path; and a web positioning device for generating a vacuum that acts only on the first face of the web of material to arrest movement of the web of material, wherein activation of the web positioning device creates a tension sub-zone along the web travel path for minimizing undesired effects of a web upset.
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority from U.S. Provisional Patent Application Serial No. 60/447,820 filed Feb. 14, 2003.
Provisional Applications (1)
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Number |
Date |
Country |
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60447820 |
Feb 2003 |
US |