Method for making filtering material for tobacco products
Abstract
Abstract Method for treating paper to render it particularly adapted to be gathered and enclosed in a wrapper to make a filter cord subdividable into efficient cigarette filters. The paper is first moistened with a volatile, impregnating agent to prevent undue tearing in a longitudinal grooving and lateral stretching treatment which loosens and exposes fibers by passage through the nip between heated meshing rollers having alternating circumferential ribs and grooves. The impregnating agent has a boiling point and heat of evaporation less than those of water to reduce drying time. Coating materials, e.g. cellulose triacetate, cellulose acrylic acetate, may be dissolved in the impregnating agent so that the fibers of the paper will be coated with the material on evaporation of the impregnating agent.
Inventors
- 👤 Paul A Muller
- 👤 Hans Muster
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
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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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |