US4253329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fibre flexibility meter
Assignee: Domtar Inc
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Filing: 1979-11-09
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Granted: 1981-03-03
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Expires: 1999-11-09
Abstract
Abstract A method and apparatus are disclosed for obtaining an indication of fibre flexibility by spraying a pulp sample of preselected average fibre length against the bottom of a horizontal screen having a negative pressure thereabove whereby a selected pressure drop is applied across the screen and the pulp sample is divided into a retained and a passed fraction. The flexibility index is obtained by a ratio indicative of the fibre mass in the passed fraction or retained fraction to the fibre mass in the feed.
Inventors
- 👤 Alkibiadis Karnis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:50
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/34; G01N33/343
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
180 words
A method for measuring the fibre flexibility of fibres comprising; screening slurry of said fibres to obtain a feed fraction having a preselected average fibre length, adjusting the consistency of the feed fraction to a selected consistency in the range of 0.05 to 0.3%, spraying said feed fraction against the bottom of a substantially horizontal screen having openings the minimum dimensions of which are substantially equivalent to a b/L ratio of 0.3 to 0.7 for a square opening screen, wherein b equals the dimension of one side of the square opening and L equals the average fibre length of the feed fraction, maintaining a negative pressure in above said horizontal screen sufficient so as to obtain a flow of slurry through said screen but without the formation of a mat beneath said screen and to divide said feed fraction into a retained and a pass fraction, obtaining a ratio indicative of a mass of fibres in the pass or retained fraction to the mass of fibres in said feed, thereby to obtain an indication of the flexibility of the fibres.
Claim 2
Independent Claim
180 words
A method for measuring the fibre flexibility of fibres comprising; screening slurry of said fibres to obtain a feed fraction having a preselected average fibre length, adjusting the consistency of the feed fraction to a selected consistency in the range of 0.05 to 0.3%, spraying said feed fraction against the bottom of a substantially horizontal screen having openings the minimum dimensions of which are substantially equivalent to a b/L ratio of 0.3 to 0.7 for a square opening screen, wherein b equals the dimension of one side of the square opening and L equals the average fibre length of the feed fraction, maintaining a negative pressure in above said horizontal screen sufficient so as to obtain a flow of slurry through said screen but without the formation of a mat beneath said screen and to divide said feed fraction into a retained and a pass fraction, obtaining a ratio indicative of a mass of fibres in the pass or retained fraction to the mass of fibres in said feed, thereby to obtain an indication of the flexibility of the fibres.
Claim 3
Dependent Claim
13 words
A method as defined in claim 1 wherein said consistency is about 0.15%.
Claim 4
Dependent Claim
16 words
A method as defined in claim 1 wherein said b/L ratio is between 0.5 and 0.6.
Claim 5
Independent Claim
19 words
A method as defined in claims 1, 2 or 3 wherein said negative is in the "stabilized" flow region.
Claim 6
Independent Claim
28 words
A method as defined in claims 1, 2 or 3 wherein a pressure drop across said screen of 20 to 25 mm of H 2 O is maintained.
Claim 7
Independent Claim
36 words
A method as defined in claims 1, 2 or 3 wherein said spraying comprise spraying said feed fraction in a manner so that the orientation of the fibres striking the bottom of said screen is random.
Claim 8
Independent Claim
125 words
An apparatus for measuring the fibre flexibility comprising, a substantially horizontal screen an upper housing communicating with the top of said screen, means for spraying a feed slurry of fibres to be tested with said fibres in random orientation onto the bottom of said horizontal screen, means for maintaining a negative pressure in said upper housing to obtain flow of a passed slurry through said screen without the formation of a mat on the bottom of said screen and divide said feed slurry into a passed and a retained fraction, means for removing said passed fraction from said upper housing whereby a radio indicative of the fibres in said passed or retained fraction to the mass of fibres in said feed slurry may be obtained.
Claim 9
Independent Claim
125 words
An apparatus for measuring the fibre flexibility comprising, a substantially horizontal screen an upper housing communicating with the top of said screen, means for spraying a feed slurry of fibres to be tested with said fibres in random orientation onto the bottom of said horizontal screen, means for maintaining a negative pressure in said upper housing to obtain flow of a passed slurry through said screen without the formation of a mat on the bottom of said screen and divide said feed slurry into a passed and a retained fraction, means for removing said passed fraction from said upper housing whereby a radio indicative of the fibres in said passed or retained fraction to the mass of fibres in said feed slurry may be obtained.
Claim 10
Dependent Claim
139 words
An apparatus as defined in claim 7 further comprising a first container and a second container and first and second screening means, said first screening means having openings larger than said second screening means, means for pumping a slurry from said first chamber to first screening means thereby to separate said sample into a retained fraction and a pass fraction, collecting said pass fraction in said second chamber, means for pumping said pass fraction from said second chamber to said second screening means to form a second pass and a second retained fraction, means for conducting said second retained fraction to said second chamber, and means for connecting said first or said second chamber to said nozzle means to direct a pulp fraction accumulated in said first or said second chamber selectively against the bottom of said horizontal screen.
References Cited (Backward Citations)
US3873416A
Cited
US3893334A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |