US3840429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-rewet membrane for an extended press nip system
Assignee: Beloit Corp
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Filing: 1972-08-07
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Granted: 1974-10-08
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Expires: 1992-08-07
Abstract
Abstract A press mechanism and method for removing liquid from a traveling fibrous web of the type such as formed in a paper making machine and received from the fourdrinier section with the press providing an extended nip formed between a pair of traveling belts or between a belt and a roll with pressure applied to the web through the belts by hydraulic chambers or by the tension of a belt against the roll. A felt receives the liquid from the web, and a thin porous sheet of a predetermined porosity is placed between the web and felt to inhibit the flow of water between. The compressing time exceeds the release time so that a greater amount of water will flow from the web to the felt than will return to the web.
Inventors
- 👤 L Busker
- 👤 R Daane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:49
CPC Classifications
B; B30; B30B; B30B9/00; B30B9/02; B30B9/24; D; D21; D21F; D21F3/00; D21F3/02; D21F3/0209; D21F3/029; Y; Y10; Y10S; Y10S162/00; Y10S162/90
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
94 words
THE METHOD OF PRESSING LIQUID FROM A TRAVELLING FIBROUS WEB WHILE THE WEB PASSES THROUGH AN EXTENDED PRESS NIP WHICH COMPRISES, APPLYING PRESSURE TO THE TRAVELLING WEB OVER A COMPRESSION TIME FOR SQUEEZING LIQUID THEREFROM AND THEREAFTER RELEASING THE PRESSURE WITH THE COMPRESSION TIME SUBSTANTIALLY EXCEEDINGLY THE RELEASE TIME, COLLECTING THE LIQUID SQUEEZED FROM THE WEB IN A LIQUID RECEIVING MEANS TRAVELLING ADJACENT THE WEB SURFACE, AND THEREAFTER INHIBITING THE REWETTING OF THE WEB BY A RETURN FLOW OF LIQUID BETWEEN THE LIQUID RECEIVING MEANS AND THE WEB BY PLACING A POROUS SHEET THEREBETWEEN.
Claim 2
Independent Claim
94 words
THE METHOD OF PRESSING LIQUID FROM A TRAVELLING FIBROUS WEB WHILE THE WEB PASSES THROUGH AN EXTENDED PRESS NIP WHICH COMPRISES, APPLYING PRESSURE TO THE TRAVELLING WEB OVER A COMPRESSION TIME FOR SQUEEZING LIQUID THEREFROM AND THEREAFTER RELEASING THE PRESSURE WITH THE COMPRESSION TIME SUBSTANTIALLY EXCEEDINGLY THE RELEASE TIME, COLLECTING THE LIQUID SQUEEZED FROM THE WEB IN A LIQUID RECEIVING MEANS TRAVELLING ADJACENT THE WEB SURFACE, AND THEREAFTER INHIBITING THE REWETTING OF THE WEB BY A RETURN FLOW OF LIQUID BETWEEN THE LIQUID RECEIVING MEANS AND THE WEB BY PLACING A POROUS SHEET THEREBETWEEN.
Claim 3
Dependent Claim
168 words
A press mechanism for removing liquid from a traveling fibrous web which comprises, an extended press nip having opposed pressing surfaces for receiving a traveling web and applying pressing force to the web uniformly thereacross with the web being released on the offrunning side of the nip, the period of time of application of the pressure being larger than the release time, a traveling felt means passing through the nip with the web for receiving moisture pressed from the web, and a thin porous sheet passing through the nip between the felt and the web having distributed openings to reduce the rate of flow of liquid from the felt back to the web on the offrunning side, said sheet having a permeability in the range of 5 X 10 10 to 0.1 X 10 10 whereby the flow of liquid from the web to the felt means during the period of time of application of the pressure is substantially greater than the return flow during the time. time
Claim 4
Dependent Claim
168 words
A press mechanism for removing liquid from a traveling fibrous web which comprises, an extended press nip having opposed pressing surfaces for receiving a traveling web and applying pressing force to the web uniformly thereacross with the web being released on the offrunning side of the nip, the period of time of application of the pressure being larger than the release time, a traveling felt means passing through the nip with the web for receiving moisture pressed from the web, and a thin porous sheet passing through the nip between the felt and the web having distributed openings to reduce the rate of flow of liquid from the felt back to the web on the offrunning side, said sheet having a permeability in the range of 5 X 10 10 to 0.1 X 10 10 whereby the flow of liquid from the web to the felt means during the period of time of application of the pressure is substantially greater than the return flow during the time. time
Claim 5
Dependent Claim
31 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said felt means is hydrophilic and said porous sheet has a hydrophobic characteristic.
Claim 6
Dependent Claim
28 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said felt means has been treated with a wetting agent.
Claim 7
Dependent Claim
25 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said porous sheet is constructed of polytetrafluoroethylene.
Claim 8
Dependent Claim
27 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said porous sheet is coated with a hydrophobic material.
Claim 9
Dependent Claim
42 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said porous sheet is integral with the felt and forms a layer between the web and the more absorbent outer portion of the felt.
Claim 10
Dependent Claim
46 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said pressing surfaces are formed by a pair of traveling belts each having a fluid backing pressure chamber for transmitting fluid pressure to the web through the belts.
Claim 11
Dependent Claim
48 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said pressing surfaces are formed by a supporting rotating roll on one side of the web and a tensioned belt wrapping an arc of the roll on the other side.
Claim 12
Dependent Claim
66 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said felt means and said sheet are integral and form one of the surfaces for applying a pressing force to the web and the other surface is formed by a rotating roll with the felt wrapping an arc of the roll, and including means for tensioning the felt.
Claim 13
Dependent Claim
26 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said sheet is formed of a stainless steel.
Claim 14
Dependent Claim
26 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein said sheet is formed of a plastic material.
Claim 15
Dependent Claim
31 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein the porous sheet has permeability on the order of .5 X 10 10.
Claim 16
Dependent Claim
40 words
A press mechanism for removing liquid from a traveling fibrous web constructed in accordance with claim 2 wherein the ratio of period of time of application of pressure to the release time is on the order of 20 to one.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |