US2928765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filter paper and method of making same
Assignee: C H Dexter & Sons Inc
•
Filing: 1957-02-11
•
Granted: 1960-03-15
•
Expires: 1977-02-11
Abstract
No abstract record available.
Inventors
- 👤 Homer L Kurjan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:21
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/18; D; D21; D21F; D21F11/00; D21F11/02; D21F11/04; D21F11/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
A METHOD OF FORMING A WATER-LAID HIGHLY PERMEABLE MULTIPHASE PAPER SHEET SUITABLE FOR USE AS AN AIR FILTERING MEDIUM COMPRISING THE STEPS OF FLOWING A DILUTE SLURRY OF UNBEATEN REDWOOD BARK FIBERS ONTO A TRAVELLING WIRE SCREEN TO FORM A BASE LAYER OF SUCH FIBERS, IMMEDIATELY THEREAFTER FLOWING A DILUTE SLURRY OF ORDINARY PAPER MAKING FIBERS OVER THE REDWOOD BARK FIBERS TO FORM A COHESIVE TOP LAYER OF THE PAPER MAKING FIBERS, AND DRYING THE RESULTING WEB WHILE MAINTAINING THE WEB IN UNCOMPACTED FORM TO PRODUCE A FLEXIBLE SELF-SUSTAINING SHEET HAVING RELATIVELY LOOSE REDWOOD BARK FIBERS ON ONE SIDE AND A PAPER BONDING LAYER ON THE OTHER.
Claim 2
Independent Claim
107 words
A METHOD OF FORMING A WATER-LAID HIGHLY PERMEABLE MULTIPHASE PAPER SHEET SUITABLE FOR USE AS AN AIR FILTERING MEDIUM COMPRISING THE STEPS OF FLOWING A DILUTE SLURRY OF UNBEATEN REDWOOD BARK FIBERS ONTO A TRAVELLING WIRE SCREEN TO FORM A BASE LAYER OF SUCH FIBERS, IMMEDIATELY THEREAFTER FLOWING A DILUTE SLURRY OF ORDINARY PAPER MAKING FIBERS OVER THE REDWOOD BARK FIBERS TO FORM A COHESIVE TOP LAYER OF THE PAPER MAKING FIBERS, AND DRYING THE RESULTING WEB WHILE MAINTAINING THE WEB IN UNCOMPACTED FORM TO PRODUCE A FLEXIBLE SELF-SUSTAINING SHEET HAVING RELATIVELY LOOSE REDWOOD BARK FIBERS ON ONE SIDE AND A PAPER BONDING LAYER ON THE OTHER.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-03-15 | 1963-09-14 | 1964-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-03-15 | 1967-09-14 | 1968-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-03-15 | 1971-09-14 | 1972-03-15 | $7700.00 | Window Closed / Lapsed |