Patent US4687438A successfully refreshed from Google Patents.
Patent US3658642A successfully refreshed from Google Patents.
US3658642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing curl in making a continuous web of paper
Assignee: Beloit Corp
•
Filing: 1970-08-27
•
Granted: 1972-04-25
•
Expires: 1990-08-27
Abstract
Abstract The method involves the use of upper and lower drying sections, each comprising a plurality of steam-heated drying rolls, which are employed in the drying of the paper web as it passes therebetween. A first control loop is associated with the upper section and a second control loop is associated with the lower section. These dryer loops determine the respective amounts of steam delivered to the two sections. A moisture control loop outputs a set point to the first dryer loop and a second set point is provided for the second dryer loop, and the second set point being modified so that the rate of steam flow to the second dryer section is maintained in a preferred relationship to the rate supplied by the first dryer section so that the curl of the web is minimized.
Inventors
- 👤 Marion A Keyes
- 👤 John A Gudaz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:42
CPC Classifications
D; D21; D21G; D21G9/00; D21G9/0009; D21G9/0036; Y; Y10; Y10S; Y10S162/00; Y10S162/06; Y10S162/09; Y10S162/10; Y10S162/11
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
86 words
The method of claim 1 in which one of said sides faces upwardly and the other of said sides faces downwardly, the heat applied to said upper side being varied in accordance with the amount of moisture contained in said web to maintain the moisture content of said web at said desired level and the amount of heat applied to said lower side being varied in said preferred relationship to that of said upper side whereby a reduction in the curl of said web is maintained.
Claim 2
Dependent Claim
62 words
The method of claim 1 in which the heat applied to said one side is varied in accordance with a ratio of the difference between the desire moisture for said web and the actual moisture in said web with respect to a desired ratio to provide said predetermined relationship with respect to the heat applied to said other side of said web.
Claim 3
Independent Claim
180 words
The method of reducing curl in the making of a continuous web of paper comprising the steps of directing heat against one side of said web in accordance with the moisture contained in said web after at least some drying thereof has been accomplished to maintain a preferred level of moisture in said web, directing heat against the other side of said web in relationship with the heat directed to said one side to initially reduce the curl of said web, adjusting the relationship of the amount of heat directed to said other side of the web with respect to the amount of heat being directed to said one side of the web until a desired reduction in the degree of curl of said web has been effected, and thereafter maintaining said relationship of the amount of heat directed to the other side of said web with respect to the amount of heat directed to said one side of the web while substantially maintaining the desired moisture content of said web at said preferred level of moisture in said web.
Claim 4
Dependent Claim
80 words
The method of claim 4 in which said relationship of the heat directed against said other side with respect to the heat directed against said one side is varied until said relationship effecting said desired reduction in curl is achieved, said relationship constituting a preferred relationship of the heat directed to said other side with respect to the heat directed to said one side and said preferred relationship is thereafter maintained while maintaining said moisture content at said desired level.
Claim 5
Dependent Claim
57 words
The method of claim 5 in which the heat directed against said other side is varied in accordance with a ratio of the difference between the desired moisture for said web and the actual moisture in said web with respect to a desired ratio to provide said predetermined relationship to the heat directed to said one side.
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |