Claims
- 1. A smoking filter comprising:
- a first filter plug having:
- a central core of a gathered corrugated web filter material, and
- a peripheral layer of a fibrous tow filter material surrounding said central core; wherein:
- each of said central core and said peripheral layer has a resistance-to-draw, said central core having a resistance-to-draw of between about 285 mm W.G. and about 500 mm W.G. and said filter having a resistance-to-draw of between about 115 mm W.G. and about 225 mm W.G., said peripheral layer having a lower resistance-to-draw than said central core, to initially direct, when said filter is attached to a smoking article and said smoking article is smoked, a greater fraction of smoke through said peripheral layer than through said central core; said first filter plug further having:
- carbon particles distributed throughout said central core, said carbon particles having:
- a size distribution such that 94% of said particles are between about 20 mesh and about 70 mesh,
- a moisture content between about 15.5% and about 20.5% of dry weight of the carbon particles, and
- CCl.sub.4 activity between about 50% and about 60%;
- means for admitting ventilation air through said peripheral layer toward said central core, whereby smoke initially directed into said peripheral layer flows back into said central core; whereby:
- when said filter is attached to a smoking article and said smoking article is smoked, said filtered smoking article delivers smoke containing a particular level of total particulate matter, and the taste of said smoking article is a taste associated with smoke having a level of total particulate matter higher than said particular level.
- 2. The smoking filter of claim 1 wherein said fibrous tow is cellulose acetate tow.
- 3. The smoking filter of claim 2 wherein said cellulose acetate tow has a denier per filament of about 8.0 and a total denier of about 30,000.
- 4. The smoking filter of claim 1 wherein said web material is paper.
- 5. The smoking filter of claim 4 wherein said paper is creped before being corrugated and gathered into said filter.
- 6. The smoking filter of claim 1 wherein said web material is a nonwoven web.
- 7. The smoking filter of claim 6 wherein said nonwoven web is cellulose acetate sheet.
- 8. The smoking filter of claim 1 wherein said gathered corrugated web material is wrapped in a plug wrap.
- 9. The smoking filter of claim 8 wherein said plug wrap is porous.
- 10. The smoking filter of claim 8 wherein said plug wrap contains flavor components.
- 11. The smoking filter of claim 10 wherein said plug wrap comprises a tobacco-containing material.
- 12. The smoking filter of claim 11 wherein said tobacco-containing material comprises reconstituted tobacco sheet.
- 13. The smoking filter of claim 10 wherein said plug wrap comprises plug wrap paper to which flavor components have been added.
- 14. The smoking filter of claim 13 wherein said flavor components comprise soluble tobacco components.
- 15. The smoking filter of claim 1 having a filtration efficiency of about 61% measured as if unventilated.
- 16. The smoking filter of claim 1 having a ventilation rate of about 67%.
- 17. The smoking filter of claim 16 having a filtration efficiency of about 76%.
- 18. The smoking filter of claim 1 wherein said core has a cross-sectional area occupying about 60% of the total cross-sectional area of said filter.
- 19. The smoking filter of claim 1 wherein said filter has a resistance-to-draw of about 146 mm W.G., said central core having a resistance-to-draw of about 400 mm W.G.
- 20. The smoking filter of claim 1 wherein said filter has a resistance-to-draw of about 135 mm W.G., said central core having a resistance-to-draw of about 370 mm W.G.
- 21. The smoking filter of claim 1, further comprising a second filter plug of cellulose acetate tow adjacent said first filter plug.
- 22. The smoking filter of claim 21 wherein said first filter plug has a resistance-to-draw of between about 85 mm W.G. and about 175 mm W.G., said central core having a resistance-to-draw of between about 195 mm W.G. and about 450 mm W.G., and said second filter plug has a resistance-to-draw of between about 10 mm W.G. and about 45 mm W.G, such that said filter has a resistance-to-draw of between about 100 mm W.G. and about 180 mm W.G.
- 23. The smoking filter of claim 22 wherein said first filter plug has a resistance-to-draw of about 146 mm W.G., said inner core having a resistance-to-draw of about 357 mm W.G., and said second filter plug has a resistance-to-draw of about 14 mm W.G., such that said filter has a resistance-to-draw of about 160 mm W.G.
- 24. The smoking filter of claim 1 further comprising tipping wrapped therearound, said tipping extending beyond a first end of said first filter plug for attaching said filter to a cigarette and extending beyond a second end of said first filter plug opposite said first end, forming a mouth-end recess in said filter.
- 25. The smoking filter of claim 1 wherein said core and said peripheral layer are concentric.
- 26. The smoking filter of claim 1 comprising between about 5 mg and about 35 mg of said carbon particles.
- 27. The smoking filter of claim 26 comprising about 10 mg of said carbon particles.
- 28. The smoking filter of claim 1 wherein said carbon particles have a moisture content of about 18% of the dry weight of said carbon particles.
- 29. The smoking filter of claim 1 wherein said carbon particles have a CCl.sub.4 activity of about 55%.
- 30. The smoking filter of claim 1 wherein said carbon particles are substantially uniformly distributed throughout said central core.
- 31. The smoking filter of claim 1 wherein said carbon particles are held in place by an adhesive material.
- 32. The smoking filter of claim 31 wherein said adhesive material is a liquid tack solution.
- 33. The smoking filter of claim 32 wherein said liquid tack solution is a solution of hydroxy-propylcellulose.
- 34. The smoking filter of claim 33 wherein said solution comprises about 7.5% hydroxypropyl-cellulose by weight in water.
- 35. The smoking filter of claim 31 wherein said web includes about 1% of said adhesive material by dry weight of the web.
- 36. The smoking filter of claim 33 wherein said web includes about 1% of said adhesive material by dry weight of the web.
- 37. The smoking filter of claim 34 wherein said web includes about 1% of said adhesive material by dry weight of the web.
- 38. The smoking filter of claim 1 having a ventilation rate between about 50% and about 75%.
- 39. The smoking filter of claim 1 having a ventilation rate of about 68%.
- 40. The smoking filter of claim 1 wherein the moisture content is about 18% of dry weight of the carbon particle.
- 41. The smoking filter of claim 1 further comprising tipping wrapped about said peripheral layer.
- 42. The smoking filter according to claim 41 wherein ventilation holes are provided in said tipping.
- 43. The smoking filter of claim 42 having a ventilation rate between about 50% and about 75%.
- 44. The smoking filter of claim 42 having a ventilation rate of about 68%.
- 45. The smoking filter of claim 42 having a ventilation rate of about 67%.
- 46. The smoking filter of claim 21 having a ventilation rate between about 50% and about 75%.
- 47. The smoking filter of claim 21 having a ventilation rate of about 68%.
- 48. The smoking filter of claim 21 having a ventilation rate of about 67%.
- 49. The smoking filter of claim 23 having a ventilation rate of about 67%.
- 50. The smoking filter of claim 1 wherein said peripheral layer of fibrous tow filter material has a "Y" cross-sectional shape.
- 51. The smoking filter of claim 1 wherein said peripheral layer of fibrous two filter material has crosswise creping.
- 52. The smoking filter of claim 51 wherein the crosswise creping to 10%.
- 53. The smoking filter of claim 8 further comprising tipping wrapped about said plug wrap.
- 54. The smoking filter according to claim 53 wherein ventilation holes are provided in said tipping.
- 55. The smoking filter of claim 54 having a ventilation rate between about 50% and about 75%.
- 56. The smoking filter of claim 54 having a ventilation rate of about 68%.
- 57. The smoking filter of claim 54 having a ventilation rate of about 67%.
- 58. The smoking filter of claim 9 further comprising tipping wrapped about said plug wrap.
- 59. The smoking filter according to claim 58 wherein ventilation holes are provided in said tipping.
- 60. The smoking filter of claim 59 having a ventilation rate between about 50% and about 75%.
- 61. The smoking filter of claim 59 having a ventilation rate of about 68%.
- 62. The smoking filter of claim 59 having a ventilation rate of about 67%.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of copending, commonly-assigned U.S. patent application Ser. No. 07/796,631, filed Nov. 22, 1991, which is a continuation-in-part of U.S. patent application Ser. No. 07/571,878, filed Aug. 24, 1990, now abandoned.
US Referenced Citations (29)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2007022 |
Jul 1990 |
CAX |
1531543 |
Jul 1968 |
FRX |
5832587 |
Feb 1976 |
JPX |
Continuation in Parts (2)
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Number |
Date |
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Parent |
796631 |
Nov 1991 |
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Parent |
571878 |
Aug 1990 |
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