High pressure calendering of a paper web between heated calender rolls having non-resilient surfaces
Abstract
Abstract HIGH DENSITY PAPER WHICH HAS HIGH SURFACE SMOOTHNESS AND HIGH GLOSS AND IS ESPECIALLY WELL ADAPTED FOR USE AS A PHOTOGRAPHIC PAPER IS PREPARED BY HOT CALENDERING A PAPER WEB, WITH THE WEB BEING PASSED THROUGH AT LEAST ONE NIP DEFINED BY HEATED CALENDER ROLLS HAVING HARD SMOOTH NON-RESILIENT SURFACES AND DIRECTED ALONG A PATH WHICH PREVENTS IT FROM WRAPPING AROUND THE HEATED ROLLS. THE DESIRED COMBINATION OF PHYSICAL PROPERTIES IN THE PAPER IS OBTAINED BY EXTENDING A PRESURE ON THE WEB IN THE RANGE FROM ABOUT 10,000 TO ABOUT 50,000 POUNDS PER SQUARE INCH WHILE MAINTAINING THE HEATED CALENDER ROLLS WITH A SURFACE TEMPERATURE IN THE RANGE FROM ABOUT 250*F. TO ABOUT 500*F. AND PROVIDING AN INITAL WATER CONTENT IN THE WEB WHICH IS AT LEAST ABOUT TWO PERCENT BY WEIGHT BUT IS BELOW THE WATER CONTENT AT WHICH BLISTERING OF THE PAPER OCCURS.
Inventors
- 👤 Richard C Mack
- 👤 George Lejnieks
- 👤 Edward D Morrison
Bibliographic Details
Claims Analysis
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| 3.5 Years (Year 4) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |