Heretofore, cigarettes with high levels of ventilation have usually had unacceptably low levels of resistance to draw (RTD) unless some counter measure was in place to make-up the shortfall in RTD. In the past, high density cellulose acetate filter segments were used to address the short fall. However such filtered segments tended to reduce tar delivery (FTC), with little or no effect upon gas phase components of mainstream tobacco smoke, such as carbon monoxide (CO) and nitrogen oxide (NO). This solution tended to worsen the CO to tar (FTC) ratios in lower delivery (FTC tar) cigarettes.
Ventilation has a desirable attribute in that, when operating alone, it will reduce both the particulate phase and the gas phase of mainstream smoke. Highly ventilated cigarettes however have drawbacks in RTD as previously discussed.
In accordance with one embodiment, a smoking article comprises: a tobacco rod adapted to produce mainstream smoke; a filter having an upstream end and a downstream end, the filter arranged to receive mainstream smoke at the upstream end, the filter comprising: a tubular segment open at the downstream end thereof; and a flow restrictor contained within the tubular segment; and tipping paper attaching the filter with the tobacco rod and including an air-admissible ventilating zone at a location between the upstream end and the downstream end of the filter.
In accordance with another embodiment, a smoking article comprising a tobacco rod and a filter, the filter comprises: a paper filter tube open at a downstream end thereof and attached to the tobacco rod with tipping paper; a flow restrictor contained within the filter tube, the flow restrictor dividing the filter tube into an upstream cavity and a downstream cavity; and a ventilation zone at a location along the downstream cavity, the ventilation zone comprising a plurality of perforations extending through the tipping paper and the filter tube.
In accordance with a further embodiment, a smoking article comprises: a tobacco rod adapted to produce mainstream smoke; a filter having an upstream end and a downstream end, the filter arranged to receive mainstream smoke at the upstream end, the filter comprising: a paper tubular segment open at a downstream end thereof; and a flow restrictor contained within the tubular segment, the flow restrictor comprising a paper foam rod having at least one channel, wherein the at least one channel is introduced into an outer periphery of the paper foam rod; and tipping paper attaching the filter with the tobacco rod and including an air-admissible ventilating zone at a location between the upstream end and the downstream end of the filter.
The filter 14 preferably includes a tubular segment (or filter tube) 18 having an upstream end 20, a downstream end or mouth end 22, and a flow restrictor 30 situated within the tubular segment 18. The flow restrictor 30 preferably comprises a partition 32 having at least one orifice (or flow restriction) 34 of reduced diameter. The flow restrictor 30 divides the tubular segment 18 into an upstream segment or cavity 24, and a downstream segment or cavity 26 open at the downstream end 22 thereof. The filter 14 can also include a porous paper plug (not shown) on the downstream or mouth end 22 of the filter 14 for appearance. It can be appreciated that the porous paper plug preferably does not extend to the flow restrictor 30 in order to maintain a downstream segment or cavity 26 within the filter 14.
The tubular segment 18 is preferably made of a paper product or a biodegradable plastic or other suitable material having degradability properties. The tubular segment 18 preferably has a length 19 of approximately 20.0 to 40.0 mm and more preferably about 25.0 to 35.0 mm and most preferably approximately 27.5 to 31 mm with an inner diameter 21 of approximately 7.0 to 8.0 mm and more preferably approximately 7.4 to 7.8 mm.
Different ventilation levels (10-90%) can be incorporated into the tubular segment 18, through combinations of the flow restrictor 30, a ventilating zone 40 (or ventilation zone), the permeability of the tipping paper 16, and the permeability of the paper or material used for the tubular segment 18, to provide a desired smoke delivery (FTC tar) from the same cigarette. In accordance with one embodiment, the tubular segment 18 is preferably constructed from a rigid paper that forms a self-supporting tubular segment that can be perforated by suitable laser equipment or other device to add at least one circumferential row or series of ventilation holes 42 to the tubular segment 18.
In accordance with another embodiment, an air-admissible ventilating zone 40 (or ventilating zone) can be established with a first row (and optionally a second and possibly third rows) of ventilation holes 42 extending through the tipping paper 16 and the tubular segment 18. In the preferred embodiment, the air-admissible ventilating zone 40 is located near or adjacent to the flow restrictor 30 so that air drawn through the ventilation zone 40 is allowed to mix with the mainstream smoke before arriving at the downstream end or mouth end 22 of the filter 14. In accordance with one embodiment, the ventilation holes 42 are preferably downstream of the flow restrictor 30, such that the ventilation holes 42 are between the flow restrictor 30 and the downstream or mouth end 22. The distance between the ventilating zone 40 (or ventilation holes 42) and the downstream or mouth end 22 of the filter 14 is preferably at least 5 mm and more preferably in the range of 5-20 mm, and most preferably in the range of 10-15 mm. However, it can be appreciated that in accordance with another embodiment the ventilation holes 42 can be upstream of the flow restrictor 30, such that the ventilation holes 42 are between the tobacco rod 12 and the flow restrictor 30.
In accordance with another embodiment, the flow restrictor 30 and the ventilation zone 40 preferably achieve a ventilation level of the smoking article 10 of at least 25% and more preferably at least 50% to 90%. The ventilation level of the smoking article 10 also preferably introduces a resistance to draw (RTD) to the smoker that is at an acceptable level. The resistance to draw (RTD) can also be adjusted by changing the number and the size of the orifices 34 of the flow restrictor 30, as well as the position of the ventilation zones 40 on the filter 14. In accordance with another embodiment, the wrapping paper 13 can have high permeability or alternatively perforations can be used to achieve high tobacco rod ventilation.
Furthermore, the embodiments provide the necessary amount of resistance to draw (RTD) while maintaining the desired degree of high ventilation throughout the smoke. The latter attribute is achieved by placement of the ventilating zone 40 downstream of the restrictor 30. Furthermore, placing the ventilating zone 40 in a spaced apart relation to the downstream end or mouth end 22 assures mixing of air drawn into the filter 14 through the ventilating zone 40 with mainstream smoke drawn from the tobacco rod 12.
Preferably, the partition 32 has a diameter 36 of approximately 7.0 to 8.0 mm and more preferably approximately 7.4 to 7.8 mm. The partition 32 also preferably has one or optionally, at least one orifice 34 of a diameter 38 of about 0.2 mm to about 0.9 mm. The flow restrictor 30 may be constructed of paper, a plastic or a metal and more preferably made of a paper product, a biodegradable plastic, or other suitable material having degradability properties.
In accordance with another embodiment, a screening material (not shown) can be used to prevent loose tobacco fillers blocking the orifices 34 (or channels 60). The total cigarette or smoking article's 10 resistance to draw (RTD) as well as tar delivery is balanced with combinations of ventilating zones 40, the diameter 38 of the orifices 34 (or channels 60), and the number of orifices 34 (or channels 60). It can be appreciated that with an increased level of ventilation, the air flowing into the smoking article's burning coal will be reduced, which will reduce the amount of tobacco burned, the coal temperature, and smoke component generation. In addition, enhanced diffusion out of the cigarette paper (i.e., outer wrapper 13) resulting from the slower flow rate can further reduce the gaseous smoke components such as carbon monoxide (CO) and nitrogen oxide (NO).
It is to be appreciated that in all embodiments, the filter 14 may be constructed from simple combining techniques typically used in the industry for manufacturing cigarettes at high speeds. Additionally, each embodiment can include at least one support 28 (
It can be appreciated that with a smoking article 10 as shown in
The embodiments as shown and described herein provide the benefit of a highly ventilated smoking article with desired amounts of resistance to draw and provisions for facilitating high-speed cigarette manufacturing on conventional cigarette making equipment.
It will be understood that the foregoing description is of the preferred embodiments, and is, therefore, merely representative of the article and methods of manufacturing the same. It can be appreciated that variations and modifications of the different embodiments in light of the above teachings will be readily apparent to those skilled in the art. Accordingly, the exemplary embodiments, as well as alternative embodiments, may be made without departing from the spirit and scope of the articles and methods as set forth in the attached claims.
This application claims priority to U.S. Patent Provisional Application No. 60/906,118, filed Mar. 9, 2007, which is incorporated herein by this reference in its entirety.
Number | Date | Country | |
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60906118 | Mar 2007 | US |