Claims
- 1. A drying section for drying a web in a papermaking machine, the drying section comprising a pre-drying section and a final drying section, wherein the pre-drying section includes a hot press comprising:a first press member and a rotatable counter roll in engagement with each other so as to form a nip therebetween through which the web passes; a heating device disposed in heat-transfer relation to a cylindrical exterior surface of the counter roll and operable to heat a region of said surface of the counter roll, the surface region then passing through the nip so as to heat the web therein; and an imprinting fabric arranged in an endless loop, the imprinting fabric defining an imprinting surface for imprinting the web and being arranged to pass through the nip of the hot press with the web against the imprinting surface such that the web is imprinted, the imprinted web continuing to be supported on the imprinting fabric downstream of the hot press at least up to the final drying section, wherein the imprinting fabric and web are arranged such that one side of the web is against the counter roll and the opposite side of the web is against the imprinting fabric as the web passes through the nip.
- 2. The drying section of claim 1, wherein the counter roll has a mantle defining a smooth surface that contacts the web.
- 3. The drying section of claim 1, wherein the counter roll has a mantle defining an imprinting surface that contacts the web and imprints the side of the web in contact therewith.
- 4. The drying section of claim 1, wherein the imprinting fabric is arranged to maintain the web against the counter roll over a sector of the counter roll subtending an angle of about 90° to 300°.
- 5. The drying section of claim 4, further comprising a ventilation hood surrounding a portion of said sector of the counter roll.
- 6. The drying section of claim 1, wherein the first press member includes a press shoe forming an extended nip with the counter roll.
- 7. The drying section of claim 1, further comprising a clothing arranged in an endless loop such that the clothing passes through the nip with the imprinting fabric sandwiched between the clothing and the web and then separates from the imprinting fabric and the web downstream of the nip, the clothing being operable to carry water away from the web.
- 8. The drying section of claim 1, further comprising at least one suction device disposed upstream of the nip for suctioning the web against the imprinting surface of the imprinting fabric such that the web is made to conform to the imprinting surface.
- 9. The drying section of claim 1, wherein the final drying section includes a heated dryer roll, and wherein the imprinting fabric loop includes a guide roll that forms a nip with the heated dryer roll through which the imprinting fabric with the web supported thereon passes, the web being transferred from the imprinting fabric onto the heated dryer roll at the nip.
- 10. The drying section of claim 1, wherein the final drying section includes a rotary through-air dryer having a drying cylinder about which the imprinting fabric is wrapped so as to carry the web about the drying cylinder.
- 11. The drying section of claim 1, wherein the final drying section includes a rotary through-air dryer having a drying cylinder and further includes a drying fabric arranged in an endless loop so as to pass over the drying cylinder, the imprinting fabric loop being arranged to transfer the web from the imprinting fabric onto the drying fabric upstream of the drying cylinder, the drying fabric carrying the web about the drying cylinder.
- 12. The drying section of claim 1, wherein the counter roll comprises a rotatable roll body and a heatable sleeve loosely encircling the roll body so as to allow free expansion and contraction of the sleeve relative to the roll body.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9902319 |
Jun 1999 |
SE |
|
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/141,683, filed Jun. 30, 1999, and Swedish Patent Application No. 9902319-4 filed Jun. 17, 1999.
US Referenced Citations (18)
Foreign Referenced Citations (6)
Number |
Date |
Country |
43 21 403 |
Jan 1994 |
DE |
196 54 345 |
Jun 1998 |
DE |
0490655 |
Jun 1992 |
EP |
WO9323613 |
Nov 1993 |
WO |
9323614 |
Nov 1993 |
WO |
WO9855691 |
Dec 1998 |
WO |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/141683 |
Jun 1999 |
US |