Tobacco – Smoke separator or treater
Patent
1996-12-20
1998-11-24
Yu, Mickey
Tobacco
Smoke separator or treater
131334, A24B 1500
Patent
active
058394486
DESCRIPTION:
BRIEF SUMMARY
This invention relates to absorbent articles, particularly for use as body elements of cigarette filters, and to methods for their manufacture.
Fibre-containing filters for cigarettes are well known. In one known form of construction, the filter body consists of a tow of continuous filaments, commonly cellulose acetate (acetate) filaments, arranged parallel to the long axis of the cigarette. In another known form of construction, the filter body consists of pleated or fluted paper compressed into a cylinder. Such forms of construction contain a single filter element and may be called `mono` filters. Another known form of construction is the so-called `dual` filter which contains two filter elements, for example a paper filter towards the interior and a tow filter towards the exterior of the cigarette. A further known form of construction is the so-called `triple` filter, which resembles a dual filter except that a quantity of activated carbon is interposed between the two filter elements hereinbefore mentioned.
Paper filters are known to be generally more efficient than tow filters at removing tar from tobacco smoke. High tar removal efficiency is particularly desirable in view of the trend towards low-tar cigarettes. Paper filters absorb moisture from the tobacco smoke as the cigarette is smoked, with the result that they become soggy and easy to compress, and offer increased resistance to the passage of smoke through the filter. The external end of a cigarette filter generally becomes stained as the cigarette is smoked. It is known that acetate filters generally exhibit a light tan, uniform staining, whereas paper filters generally exhibit a darker, mottled staining, the latter effect being visually undesirable. Mono paper filters are generally less expensive to manufacture than acetate tow filters even though the manufacturing process is more complex, because paper is a cheaper material than acetate. Dual filters are generally more expensive to manufacture than either mono paper or tow filters because the manufacturing process is more complex, and triple filters more expensive still. It is an object of the present invention to provide a cigarette filter with high tar removal efficiency which overcomes at least some of the disadvantages associated with those conventional paper filters which comprise paper in the filter body.
The present invention provides a cigarette filter characterised in that the body of the filter comprises entangled continuous filaments of lyocell. The present invention further provides a cigarette containing such a filter.
Lyocell filaments and fibres are known materials, and their manufacture is described for example in U.S. Pat. No. 4,246,221. They are readily biodegradable. They are available commercially from Courtaulds plc. They are made by dissolving cellulose in a solvent and extruding the solution so formed through a spinnerette into a coagulating bath which serves to precipitate the cellulose and wash the solvent from the fibre. This process may be called solvent-spinning, and lyocell fibres may also be called solvent-spun cellulose fibres. The cellulose is usually woodpulp. The solvent may be a tertiary amine N-oxide, preferably N-methylmorpholine N-oxide, and in general contains a small proportion of water. If the solvent is a tertiary amine N-oxide, the coagulating bath is preferably an aqueous bath. Fabrics which consist essentially of lyocell filaments and/or fibres may be called lyocell fabrics. The solvent-spinning process is to be distinguished from other known processes for the manufacture of cellulose fibres which rely on the formation and decomposition of a chemical derivative of cellulose, for example the viscose process.
In one embodiment of the invention, the body of the filter of the invention comprises a hydroentangled web which comprises one or more layers of lyocell filaments in the form of spread tow. If desired, the web may in addition comprise one or more layers of parallelised staple fibres, preferably lyocell staple fibres. Hydroentangling is a proce
REFERENCES:
patent: 3485706 (1969-12-01), Evans
patent: 4416698 (1983-11-01), McCorsley, III
patent: 5562739 (1996-10-01), Urben
patent: 5582843 (1996-12-01), Sellars et al.
"All You Need To Know About Tencel", Stan Davies, Textile Horizons, Feb. 1989.
Anderson Charles W.
Courtaulds Fibres (Holdings) Limited
Yu Mickey
LandOfFree
Absorbent articles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Absorbent articles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Absorbent articles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1693940