Claims
- 1. An apparatus for making a sheet material web comprising:a forming section comprising at least one forming fabric adapted to support said sheet material web as said sheet material web is formed thereon; a drying section adapted to dry said sheet material web as said sheet material web is carried through said drying section; a winding section; and a calender section comprising first and second calender rolls forming a nip and at least one carrier fabric disposed between said first and second calender rolls, wherein said at least one carrier fabric is substantially air impermeable, wherein said at least one carrier fabric enters and exits said nip along a path substantially tangential to said first and second calender rolls at said nip and wherein said at least one carrier fabric does not otherwise touch said first and second calender rolls except at said nip, said carrier fabric adapted to carry said sheet material web as said sheet material web is transferred from said drying section to said winding section and to support said sheet material web as it passes through said nip between said first and second calender rolls.
- 2. The invention of claim 1 wherein said at least one carrier fabric comprises a first carrier fabric and a second carrier fabric, said first and second carrier fabrics adapted to carry said sheet material web therebetween as said sheet material web passes through said nip between said first and second calender rolls.
- 3. The invention of claim 2 wherein said first carrier fabric is substantially air permeable and wherein said second carrier fabric is substantially air impermeable.
- 4. The invention of claim 3 wherein said air permeability of said first carrier fabric is about 100 cubic feet per minute per square foot or greater and said air permeability of said second carrier fabric is less than or equal to about 20 cubic feet per minute.
- 5. The invention of claim 1 wherein said at least one carrier fabric comprises a reinforcing structure at least partially encapsulated in a polymer.
- 6. The invention of claim 5 wherein said polymer is a polyurethane polymer.
- 7. The invention of claim 1 wherein at least one of said first and second calender rolls is steel.
- 8. The invention of claim 1 wherein at least one of said first and second calender rolls comprises a resilient material contacting said at least one carrier fabric.
- 9. The invention of claim 8 wherein said other of said first and second calender rolls is steel.
- 10. The invention of claim 1 wherein said winding section comprises a reel adapted to wind said sheet material web into a roll as said sheet material web is transferred from said calender section to said reel.
- 11. The invention of claim 1 wherein said drying section comprises a drying fabric adapted to carry said sheet material web through said drying section as said sheet material web is transferred from said at least one forming fabric.
- 12. The invention of claim 11 further comprising at least one transfer fabric adapted to transfer said sheet material web from said at least one forming fabric to said at least one drying fabric.
- 13. The invention of claim 1 wherein said first and second calender rolls apply a load therebetween in the range of between about 50 pounds per lineal inch and about 400 pounds per lineal inch.
- 14. The invention of claim 1 wherein said at least one carrier fabric comprises a compressible surface layer contacting said dried sheet material web.
- 15. The invention of claim 14 wherein said surface layer defines a substantially monoplanar and continuous web contacting surface.
- 16. The invention of claim 1 wherein said second carrier fabric comprises a compressible surface layer adapted to contact the sheet material web.
- 17. The invention of claim 16 wherein said surface layer defines a substantially monoplanar and continuous web contacting surface.
- 18. An apparatus for making a sheet material web comprising:a forming section comprising at least one forming fabric adapted to support said sheet material web as said sheet material web is formed thereon; a drying section comprising at least one drying fabric adapted to carry said sheet material web through said drying section as said sheet material web is transferred from said at least one forming fabric; and a calender section comprising first and second calender rolls forming a nip and first and second carrier fabrics disposed between said first and second calender rolls, wherein said first and second carrier fabrics exit said nip in a parallel relationship along a path substantially tangential to said first and second calender rolls at said nip, wherein said first and second carrier fabrics do not otherwise touch said first and second calender rolls as said first and second carrier fabrics exit said nip except at said nip, and wherein said first carrier fabric is substantially air permeable and wherein said second carrier fabric is substantially air impermeable, said first and second carrier fabrics adapted to carry said sheet material web therebetween as said sheet material web is transferred from said drying section and to support said sheet material web as it passes through said nip between said first and second calender rolls.
- 19. The invention of claim 18 further comprising a winding section, wherein said first and second carrier fabrics are adapted to carry said sheet material web as said sheet material web is transferred between said drying section to said winding section.
- 20. The invention of claim 19 wherein said winding section comprises a reel adapted to wind said sheet material web into a roll as said sheet material web is transferred from said calender section to said reel.
- 21. The invention of claim 18 wherein said air permeability of said first carrier fabric is about 100 cubic feet per minute per square foot or greater and said air permeability of said second carrier fabric is less than or equal to about 20 cubic feet per minute.
- 22. The invention of claim 18 wherein said at second carrier fabric comprises a reinforcing structure at least partially encapsulated in a polymer.
- 23. The invention of claim 22 wherein said polymer is a polyurethane polymer.
- 24. The invention of claim 18 wherein at least one of said first and second calender rolls is steel.
- 25. The invention of claim 18 wherein at least one of said first and second calender rolls comprises a resilient material contacting said at least one carrier fabric.
- 26. The invention of claim 25 wherein said other of said first and second calender rolls is steel.
- 27. The invention of claim 18 further comprising at least one transfer fabric adapted to transfer said sheet material web from said at least one forming fabric to said at least one drying fabric.
- 28. The invention of claim 18 wherein said first and second calender rolls apply a load therebetween in the range of between about 50 pounds per lineal inch and about 400 pounds per lineal inch.
- 29. An apparatus for making a sheet material web comprising:a forming section comprising at least one forming fabric supporting a wet sheet material web as said wet sheet material web is formed thereon; a drying section comprising at least one drying fabric carrying said wet sheet material web through said drying section as said wet sheet material web is transferred from said at least one forming fabric; and a calender section comprising first and second,calender rolls forming a nip and at least one carrier fabric disposed between said first and second calender rolls, wherein said at least one carrier fabric is substantially air impermeable and wherein said at least one carrier fabric carries a dried sheet material web from said drying section and supports said dried sheet material web as it passes through said nip between said first and second calender rolls, wherein said dried sheet material web has a first thickness as it leaves said drying section and a second thickness after it passes through said calender nip, wherein said second thickness is less than said first thickness, and wherein said second thickness is from about 50% to about 80% of said first thickness.
- 30. The invention of claim 29 wherein said first thickness is between about 0.020 inches and about 0.050 inches, and wherein said second thickness of said sheet material web is between about 0.008 inches and about 0.020 inches.
- 31. The invention of claim 29, wherein said at least one carrier fabric comprises a first carrier fabric and a second carrier fabric; said first and second carrier fabrics carrying said dried sheet material web therebetween as said sheet material web passes through said nip between said first and second calender rolls.
- 32. The invention of claim 31 wherein said first carrier fabric is substantially air permeable and wherein said second carrier fabric is substantially air impermeable.
- 33. The invention of claim 32 wherein said air permeability of said first carrier fabric is about 100 cubic feet per minute per square foot or greater.
- 34. The invention of claim 32 wherein said air permeability of said second carrier fabric is about 20 cubic feet per minute per square foot or less.
- 35. The invention of claim 29 wherein said at least one carrier fabric comprises a reinforcing structure at least partially encapsulated in a polymer.
- 36. The invention of claim 35 wherein said polymer is a polyurethane polymer.
- 37. The invention of claim 19 wherein at least one of said first and second calender rolls is steel.
- 38. The invention of claim 19 wherein at least one of said first and second calender rolls comprises a resilient material contacting said at least one carrier fabric.
- 39. The invention of claim 19 further comprising a winding section, wherein said first and second carrier fabrics carry said dried sheet material web from said drying section to said winding section.
- 40. The invention of claim 29 wherein said winding section comprises a reel, wherein said dried sheet material web is wound into a roll on said reel as said dried sheet material web is transferred from said calender section to said reel.
- 41. The invention of claim 29 further comprising at least one transfer fabric transferring said wet sheet material web from said at least one forming fabric to said drying fabric.
- 42. The invention of claim 29 wherein said first and second calender rolls apply a load therebetween in the range of between about 50 pounds per lineal inch and about 400 pounds per lineal inch.
- 43. The invention of claim 29 wherein said at least one carrier fabric and said sheet material web exit said nip in a parallel relationship along a path substantially tangential to said first and second calender rolls at said nip.
- 44. The invention of claim 29 wherein said at least one carrier fabric comprise, a compressible surface layer contacting said dried sheet material web.
- 45. The invention of claim 44 wherein said surface layer defines a substantially monoplanar and continuous web-contacting surface.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. application Ser. No. 09/243,774, filed Feb. 3, 1999, which application is hereby incorporated by reference herein.
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