US20080047571A1 - Smoking article with plate impactor - Google Patents

Abstract

A smoking article includes a filter system having an upstream plug of filtering material, an impaction filter, and a downstream plug of filtering material. The impaction filter includes at least one plate having at least one orifice.

Description

CROSS REFERENCE TO RELATED APPLICATION
• This application claims priority under 35 U.S.C. §119(e) to U.S. provisional Application No. 60/830,104, filed on Jul. 12, 2006, the entire content of which is incorporated herein by reference.
BACKGROUND
• Cigarettes are typically categorized according to their delivery of tar (nicotine free, dry particulate matter) under standard test procedures such as the one established in 1967 by the Federal Trade Commission (FTC). The FTC method includes machine drawn puffs at 35 cm³volume for 2-second duration each, at 60-second intervals. The International Organization for Standardization (ISO) has a similar smoking protocol.
• In the 1990s, additional smoking protocols were proposed, including that of the Massachusetts Department of Public Health (MDPH), one of the so-called intense smoking regimes. The MDPH method includes machine drawn puffs at 45 cm³volume for 2-second duration each, at 30-second intervals, with 50% of the cigarette filter ventilation holes blocked.
• It has been found that commercial lit-end cigarettes tend to produce higher tar than FTC deliveries when puff draw volume, frequency of draw and/or puff duration are increased and/or ventilation holes are occluded in whole or in part. This tendency is reflected, for example, in differences in measurement of tar (FTC) and tar (MDPH) (i.e., Tar (mg/cigt)_MDPH/Tar (mg/cigt)_FTC), with tar (MDPH) being representative of a more intense drawing condition over that of the former.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of a smoking article in the form of a cigarette.
• FIG. 2 is a cross sectional view of the smoking article ofFIG. 1 with at least one impaction plate.
• FIG. 3 is a cross sectional view of another embodiment of the smoking article ofFIG. 1 with at least one impaction plate and a plug of filtering material having an activated carbon material.
• FIG. 4 is a view along the line4-4 ofFIGS. 2 and 3.
• FIG. 5 is a side view of the at least one impaction plate of the smoking article ofFIGS. 2 and 3.
• FIG. 6 is a cross sectional view according to a further embodiment of a smoking article having at least one impaction plate.
• FIG. 7 is a view along the line7-7 ofFIG. 6.
• FIG. 8 is a view along the line8-8 ofFIG. 6.
• FIG. 9 is a cross sectional view of another embodiment of a smoking article having at least one impaction plate.
• FIG. 10 is a cross sectional view of a further embodiment of a smoking article having at least one impaction plate.
• FIG. 11 is a cross sectional view of another embodiment of a smoking article having at least one impaction plate.
• FIG. 12 is a cross sectional view of a further embodiment of a smoking article having at least one impaction plate.
• FIG. 13 is a view along the line13-13 ofFIG. 12.
• FIG. 14 is a view along the line14-14 ofFIG. 12.
• FIG. 15 is a cross sectional view of another embodiment of a smoking article having at least one impaction plate.
• FIG. 16 is a cross sectional view of a further embodiment of a smoking article having at least one impaction plate.
• FIG. 17 is a view along the line17-17 ofFIG. 16.
• FIG. 18 is a view along the line18-18 ofFIG. 16.
DETAILED DESCRIPTION
• FIG. 1 shows asmoking article10 in the form of a cigarette according to one embodiment, wherein thesmoking article10 reduces the ratio of total particulate matter (TPM) and tar yield by incorporating afilter system40 into the cigarette or smokingarticle10 that becomes more efficient at removing tar at larger puff volumes. The ratio of total particulate matter (“TPM”) and tar yield between MDPH and FTC/ISO methods for a given test cigarette is referenced herein as the “delivery elasticity”.
• Referring toFIGS. 1 and 2, smokingarticles10 in the form of cigarettes typically include atobacco rod20 ofsmoking material21, contained in a circumscribingouter wrapper30. Theouter wrapper30 is typically a porous wrapping material or paper wrapper. The smokingmaterial21 is preferably a shredded tobacco or tobacco cut filler. However, anysuitable smoking material21 can be used.
• Thesmoking article10 also includes afilter system40 adjacent to themouth end14 of thetobacco rod20 such that thefilter system40 andtobacco rod20 are axially aligned in an end-to-end relationship, preferably abutting one another. Thefilter system40 has a generally cylindrical shape, and the diameter thereof is essentially equal to the diameter of thetobacco rod20. The ends (i.e., upstream end16 (FIG. 2) and downstream end18) of thefilter system40 are open to permit the passage of air and smoke therethrough. Thefilter system40 includes a plurality ofplugs42,46 (FIG. 2) of filtering material and an impaction filter44 (FIG. 2) circumscribed by aplug wrap48. Theplug wrap48 is typically a paper, which optionally incorporates a carbonaceous material. Theplug wrap48 circumscribes the total length of thefilter system40.
• Thefilter system40 attaches to thetobacco rod20 by a tippingmaterial50, which circumscribes both the entire length of thefilter system40 and an adjacent region of thetobacco rod20. The tippingmaterial50 is typically a paper like product; however, any suitable material can be used. The inner surface of the tippingmaterial50 is fixedly secured to the outer surface of theplug wrap48 and the outer surface of the wrappingmaterial30 of thetobacco rod20, using a suitable adhesive. A ventilated or air dilutedsmoking article10 can be provided with an air dilution means, such as a series of ventilation holes orperforations60, each of which extends through the tippingmaterial50 and optionally theplug wrap48. As shown inFIG. 1, ventilation of mainstream smoke can be achieved with a circumferential row (FIG. 1) or rows of ventilation holes orperforations60 about a location along thefilter system40.
• Upon lighting of the smokingarticle10, the mainstream smoke is generated by and drawn from thetobacco rod20 and through thefilter system40. Herein, the “upstream” and “downstream” relative positions between thefilter system40 and other features are described in relation to the direction of mainstream smoke as it is drawn from thetobacco rod20 and through thefilter system40.
• FIG. 2 shows a cross sectional view of the cigarette ofFIG. 1 according to one embodiment of a smokingarticle10 with theimpaction filter44 having at least oneimpaction plate70. As shown inFIG. 2, thefilter system40 is comprised of a first orupstream plug42 of filtering material, animpaction filter44 and a second ordownstream plug46 of filtering material. Theimpaction filter44 comprises a first orupstream impaction plate70 having at least one orifice72 (FIG. 4) and more preferably at least twoorifices72.
• As shown inFIG. 2, theupstream plug42 of filtering material and thedownstream plug46 of filtering material have a generally cylindrical shape, and anouter diameter52 thereof that is essentially equal to the diameter of thetobacco rod20. The filtering material is preferably cellulose acetate. However, it can be appreciated that the filtering material can be comprised of cellulose acetate with an activated carbon mixed throughout (often referred to as carbon-on-tow) or any other suitable filtering material and/or additives such as flavorants. Thefilter system40 typically has anoverall length56 of about 15 to 40 mm for asmoking article10 having anoverall length58 of about 80 to 160 mm. Thefilter system40 also can include a plurality of ventilation holes orperforations60 on either the downstream and/or upstream side of theimpaction filter44. In use, thefilter system40 incorporating the at least oneimpaction plate70 into the cigarette or smokingarticle10, minimizes the ratio of total particulate matter (TPM) and tar yield by increasing the filtration efficiency for particulates (tar) with the increase of flow rate or puff volume. Specifically, the range of TPM or tar that the smoker is exposed to, by increasing puff volume, is reduced due to the reduction in smoking elasticity, i.e. reduction in Tar (mg/cigt)_MDPH/Tar (mg/cigt)_FTC.
• FIG. 3 shows a cross sectional view of another embodiment of the smokingarticle10 with at least oneimpaction plate70 and anupstream plug42 of carbon-on-tow45. As shown inFIG. 3, thefilter system40 is comprised of anupstream plug42 of filtering material with a cellulose acetate element mixed with an activated carbon material throughout in the form of a carbon-on-tow45 plug of filtering material. It can also be appreciated that theplugs42,46 of filtering material can contain activated carbon in a cavity provided within or adjacent the upstream anddownstream plugs42,46 of cellulose acetate material. Alternatively, the upstream anddownstream plugs42,46 of filtering material can contain activated carbon or other gas-vapor phase sorbents.
• FIG. 4 shows a cross sectional view of the at least oneimpaction plate70 of the smokingarticle10 ofFIGS. 2 and 3 along the line4-4. As shown inFIG. 4, theimpaction filter44 comprises animpaction plate70 having a plurality oforifices72. Theimpaction plate70 preferably has adiameter110 of about 7.0 to 8.0 mm and more preferably about 7.4 to 7.8 mm. Theimpaction plate70 preferably has at least twoorifices72 each having adiameter112 of about 0.2 to about 0.8 mm and more preferably about 0.3 to 0.6, and most preferably about 0.4 mm. Theimpaction plate70 can be made of paper, plastic, or metal, and more preferably made of a paper product or other suitable material having degradability properties. Theimpaction plate70 preferably is made of foamed cellulose or foamed cellulose acetate or any other type of cellulosic material or cellulose acetate that can be formed into the desired shape of theimpaction plate70. The cellulosic material may be derived from tobacco, such as a cellulosic material derived from tobacco stems.
• FIG. 5 shows a side view of the at least oneimpaction plate70 of thesmoking article10 ofFIGS. 2 and 3. As shown inFIG. 5, theimpaction plate70 preferably has alength114 of about 2.0 to 6.0 mm and more preferably about 3.0 to 5.0 mm, and aninner length115 of about 1.0 to 3.0 mm and more preferably about 1.5 to 2.25 mm. The spacing116 (i.e., the difference between theouter length114 and theinner length115 divided by 2) is preferably about 1.5 to about 2.25 mm. The spacing116 created by the difference in theouter length114 and theinner length115 forms anupstream cavity118 and adownstream cavity119. Theupstream cavity118 is positioned between theupstream plug42 of filtering material and theimpaction filter44, with thedownstream cavity119 positioned between theimpaction filter44 and thedownstream plug46 of filtering material.
• FIG. 6 shows a cross sectional view of asmoking article10 according to a further embodiment having afilter system40 with animpaction filter44, which comprises a first orupstream impaction plate80 and a second ordownstream impaction plate90. As shown inFIG. 6, thefilter system40 is comprised of a first orupstream plug42 of filtering material, animpaction filter44 and a second ordownstream plug46 of filtering material. Theimpaction filter44 comprises a first orupstream plate80 having a plurality oforifices72. The plurality oforifices72 as shown inFIG. 7, are equally spaced around an outer perimeter of thefirst plate80. However, it can be appreciated that the plurality oforifices72 can be spaced in any suitable arrangement. A second ordownstream plate90 having acentral orifice92 as shown inFIG. 8 is positioned downstream of the first orupstream plate80.
• Theupstream plug42 of filtering material and thedownstream plug46 of filtering material each has a generally cylindrical shape, and anouter diameter52 thereof that is essentially equal to the outer diameter of thetobacco rod20. The filtering material is preferably a cellulose acetate material. However, the filtering material can be carbon-on-tow or any other suitable filtering material. Thefilter system40 typically has anoverall length56 of about 15 to 40 mm in length for asmoking article10 having anoverall length58 of about 80 to 160 mm. Eachplug42,46 of filtering material can have anequal length54, or the upstream anddownstream plugs42,46 can havedifferent lengths54. It can also be appreciated that thelength54 of the upstream anddownstream plugs42,46 of filtering material can vary depending on additional materials within the filtering material including activated carbons or other gas-vapor phase sorbent or additive materials.
• As shown inFIG. 6, theimpaction filter44 comprises an upstream plate80 (FIG. 7) having a plurality oforifices72 and a downstream plate90 (FIG. 8) having acentral orifice92 located an equal distance from an outer perimeter of thedownstream plate90. In one embodiment, the upstream and thedownstream plates80,90 preferably have a thickness96 (FIG. 9) of about 0.5 mm to about 1.5 mm and more preferably a thickness of about 1.0 mm. The upstream anddownstream plates80,90 preferably have the sameouter diameter110 as the upstream anddownstream plugs42,46 of filtering material. Theimpaction filter44 preferably has alength47 of about 3.0 to about 10.0 mm and more preferably about 4.0 to 7.0 mm. Theupstream plate80 and thedownstream plate90 are preferably separated by adistance49 of about 0.5 to 2.5 mm and more preferably about 0.75 to about 1.5 mm and most preferably about 1.0 mm.
• In one embodiment, as shown inFIG. 6, theupstream plug42 of filtering material anddownstream plug46 of filtering material have anouter diameter52 of about 6.5 to about 8.5 mm for animpaction filter44 having an outer diameter of about 7.4 mm to about 7.8 mm. In addition, the upstream anddownstream plugs42,46 of filtering material preferably have a length of about 2.5 mm to about 20 mm, and more preferably about 5 to 10 mm and most preferably about 7 mm for a smoking article having a length of about 80 to 160 mm. Furthermore, the upstream and thedownstream plates80,90 can have anouter diameter110 of about 6.5 to about 8.5 mm for an impaction filter having an outer diameter of about 7.5 mm. In use, theimpaction filter44 preferably has a resistance to draw (RTD) of less than 60 mm H₂O.
• The upstream anddownstream plates80,90 can be made of paper, plastic or metal of any desired thickness. However, the upstream anddownstream plates80,90 are preferably made of a paper product for degradability. The upstream anddownstream plates80,90 are placed between the upstream anddownstream plugs42,46 of filtering material, which is preferably cellulose acetate. In addition, the upstream anddownstream plates80,90 are preferably not visible to the smoker.
• FIG. 7 shows a view of theimpaction filter44 ofFIG. 6 along the line7-7. As shown inFIG. 7, theupstream plate80 has a plurality oforifice72, which are preferably equally spaced along the perimeter of the plate. Preferably, theupstream plate80 is comprised of4 to12orifices72 and more preferably about8. However, it can be appreciated that any number oforifices72 can be used. The number oforifices72 as well as their size and position in theupstream plate80 depend on the desired resistance-to-draw (RTD) or pressure drop, and efficiency for theimpaction filter44. It can be appreciated that one ormore impaction plates70 having a plurality oforifices72 can also be used. In addition, spacing between the one ormore impaction plates70 can be determined by the desired efficiency. Theorifices72 preferably have adiameter112 of about 0.2 mm to about 0.8 mm, and more preferably about 0.4 mm.
• FIG. 8 shows a cross sectional view of theimpaction filter44 ofFIG. 6 along the line8-8. As shown inFIG. 8, thedownstream plate90 has a centrally locatedorifice92. Theorifice92 has adiameter94 of about 1.0 mm to about 3.0 mm and more preferably about 2.0 mm.
• FIG. 9 shows a cross sectional view of another embodiment of asmoking article10 having afilter system40, wherein thesmoking article10 minimizes the ratio of total particulate matter (TPM) and tar yield by incorporating into thefilter system40 at least oneimpaction plate70. As shown inFIG. 9, thesmoking article10 comprises atobacco rod20 ofsmoking material21 and afilter system40 with a series of ventilation holes60. Ventilation holes60 dilute the smoke drawn through thesmoking article10. Alternatively, if the smoking article does not haveventilation holes60 or theholes60 are covered, the concentration of smoke constituents drawn through thefilter system40 is higher. The ventilation holes60 as shown inFIG. 9 are positioned upstream of theimpaction filter44. However, it can be appreciated that the ventilation holes60 can in an alternative embodiment be positioned downstream of theimpaction filter44.
• Theimpaction filter44 as shown inFIG. 9 comprises anupstream plate80 having a plurality oforifices72 and adownstream plate90 having a single centrally positionedorifice92. The ventilation holes orperforations60 on the upstream side of theimpaction filter44 minimize the ratio of total particulate matter (“TPM”) and tar yield by minimizing the flow change through the coal of thetobacco rod20 and by balancing thetobacco rod20 flow and filter40 ventilation flow as a function of the flow rate out of thedownstream end18 of thefilter system40. As a result of an increased level of ventilation from the ventilation holes orperforations60 within thefilter system40, the gaseous smoke constituents of the mainstream smoke such as carbon monoxide (CO) and nitrogen oxides (NO) can also be reduced.
• FIG. 10 shows another embodiment of asmoking article10 similar toFIG. 3 comprising afilter system40 having anupstream plug42 of filtering material in the form of a carbon-on-tow material, animpaction filter44 as shown inFIG. 9 and adownstream plug46 of cellulose acetate. As shown inFIG. 10, the series of ventilation holes orperforations60 are positioned upstream from theimpaction filter44, which is comprised of the upstream and thedownstream plates80,90. Theupstream plug42 of carbon-on-tow as shown in this embodiment is preferably about 15.0 to 30.0 mm in length, and more preferably about 20 to 25 mm in length.
• FIG. 11 shows a cross sectional view of another embodiment of asmoking article10 having afilter system40 with animpaction filter44 having upstream anddownstream plates80,90. As shown inFIG. 11, theimpaction filter44 is placed upstream from the ventilation holes or perforations60 (i.e., between thetobacco rod20 and the ventilation holes60). Using thisimpaction filter44, the ventilation levels within thesmoking article10 increase with the increase of puff volume as well, and therefore, minimizes the airflow through the coal of the burningtobacco rod20. Theupstream plate80 reduces the total particulate matter and thedownstream plate90 increases the ventilation as the puff volume increases.
• FIG. 12 shows a further embodiment of asmoking article10 as shown inFIG. 11, wherein the ventilation holes60 are positioned downstream of the upstream anddownstream plates80,90. As shown inFIG. 12, thefilter system40 is comprised of anupstream plug42 of carbon-on-tow45, animpaction filter44, and adownstream plug46 of cellulose acetate. Theimpaction filter44 is comprised of theupstream plate80 having a plurality oforifices72 and adownstream plate90 having asingle orifice92. The plurality oforifices72 for theupstream plate80 are preferably 2 to 12 in number and more preferably 4 to 8, and most preferably 4. The plurality oforifices72 preferably have adiameter112 of about 0.2 to 0.6 mm and more preferably about 0.4 mm. Thesingle orifice92 is preferably concentrically or centrally positioned within thedownstream plate90 and has adiameter94 of about 0.5 to 4 mm, and more preferably about 1.0 to 2.0 mm. Theupstream plug42 of carbon-on-tow has a length of about 10 to 20 mm and more preferably about 14 to 16 mm, theimpaction filter44 having a total length of about 5.0 mm with a 1.0 mm separation between theupstream plate80 and thedownstream plate90. Thedownstream plug46 of filtering material in the form of cellulose acetate has a length of about 10 to 20 mm and more preferably about 15 mm.
• FIG. 13 shows theupstream plate80 of thesmoking article10 as shown inFIG. 12. As shown inFIG. 13, theupstream plate80 has a plurality oforifices72, which are preferably equally spaced within the perimeter of theupstream plate80. Preferably, theupstream plate80 is comprised of 2 to 12orifices72 and more preferably 4. However, it can be appreciated that any number oforifices72 can be used. The number oforifices72 as well as their size and position in theupstream plate80 depend on the desired resistance-to-draw (RTD) or pressure drop, and efficiency for theimpaction filter44. It can be appreciated that one or moreupstream plates80 having a plurality oforifices72 can be used. In addition, spacing between the one or moreupstream plates80 anddownstream plate90 can be determined by the desired efficiency. Theorifices72 preferably have a diameter74 of about 0.2 mm to about 0.8 mm, and more preferably about 0.4 mm.
• FIG. 14 shows thedownstream plate90 of thesmoking article10 as shown inFIG. 12. As shown inFIG. 14, thedownstream plate90 has a centrally locatedorifice92. Theorifice92 has adiameter94 of about 1.0 mm to about 3.0 mm and more preferably about 2.0 mm.
• As shown inFIGS. 13 and 14, the upstream anddownstream plates80,90 preferably have the same outer diameter as thecigarette filter system40 and can be made of plastic, metal, foamed cellulose or a paper material of desired thickness. The number oforifices72,92 as well as their size and position in the upstream anddownstream plates80,90 can be any suitable number to provide a desired resistance to draw (RTD), pressure drop, ventilation levels, and particulate efficiency for theimpaction filter44. If more than one upstream anddownstream plate80,90 is used, the spacing between theplates80,90 can vary depending on the desired efficiency.
• FIG. 15 shows another embodiment of asmoking article10 having afilter system40 comprising anupstream plug42 of filtering material, animpaction filter44, a hollowacetate tube filter100 and adownstream plug46 of filtering material. As shown inFIG. 15, theimpaction filter44 is comprised of theupstream plate80 having a plurality of orifices and adownstream plate90 having asinge orifice92. The hollowacetate tube filter100 is positioned between theimpaction filter44 and thedownstream plug46 of filtering material, (i.e. downstream side of the impaction filter44). The hollowacetate tube filter100 is preferably comprised of acellulose acetate filter104 with a central orconcentric opening102. Thefiltering material104 can be optionally surrounded by aporous wrap106. Thefiltering material104 can also include carbon or other suitable materials.
• As shown inFIG. 15, thefilter system40 is preferably comprised of a anupstream plug42 of cellulose acetate tow of about 7.0 mm in length, an impaction filter of about 5.0 mm in length, a hollowacetate tube filter100 of about 15 mm in length with afiltering material104 of cellulose acetate mixed with carbon, and adownstream plug46 of cellulose acetate tow of about 6.0 to 8.0 mm in length and more preferably about 7.0 mm in length.
• FIG. 16 shows another embodiment of thesmoking article10 having animpaction filter44 having upstream anddownstream plates80,90. As shown inFIG. 17, thedownstream plate90 is coated withmicroencapsulated flavorants130. In use, upon impact of the high velocity smoke against thedownstream plate90, themicroencapsulated flavorants130 are released into the smoke stream. Themicroencapsulated flavorants130 are released as a result of the kinetic and other related forces from the high velocity smoke impacting thedownstream plate90.
• As shown inFIG. 16, thefilter system40 is comprised of anupstream plug42 of carbon-on-tow, animpaction filter44 and adownstream plug46 of cellulose acetate. Theimpaction filter44 is comprised of the upstream plate80 (FIG. 18) having a plurality oforifices72 and a downstream plate90 (FIG. 17) having asingle orifice92 withmicroencapsulated flavorants130. The plurality oforifices72 for theupstream plate80 preferably are about 2 to 12 in number and more preferably 4 to 8, and most preferably 4 and having a diameter of about 0.2 to 0.6 mm and more preferably about 0.4 mm. Thesingle orifice92 is preferably concentrically or centrally positioned within thedownstream plate90 and has a diameter of about 0.5 to 4 mm, more preferably about 1.0 to 2.0. Theupstream plug42 of carbon-on-tow has a length of about 10 to 20 mm and more preferably about 14 to 16 mm. Theimpaction filter44 preferably has a total length of about 5.0 mm with a separation of about 0.5 to 2.0 mm and more preferably about 1.0 mm between theupstream plate80 and thedownstream plate90. Thedownstream plug46 of filtering material in the form of cellulose acetate has a length of about 10 to 20 mm and more preferably about 15 mm.
• Themicroencapsulated flavorants130 can include any suitable material that generates flavor upon impaction from the mainstream smoke. Alternatively, heat from the mainstream smoke can also release theflavorants130 as a result of expansion, evaporation, distillation, decomposition or other suitable reactions to the mainstream smoke. Theflavorants130 can be a single component or a multi-flavored component that is suitable for use in cigarette manufacturing such as menthol and vanillin. Alternatively, theflavorants130 can be an aroma of choice, such as peppermint, coconut, roasted, and/or toasted aromas. However, almost any flavor oil or composition can be used. In addition, the concentration offlavorants130, on thedownstream plate90 can be adjusted or modified to provide the desired amount offlavorants130. Thus, the concentration of theflavorants130, on thedownstream plate90 can vary depending on the desired aroma and/or organoleptic qualities of the tobacco smoker. Alternatively, theflavorants130 can be encapsulated as a coating or film or within an outer shell wall in the form of a capsule having a suitable shell material such as cyclo-dextrine or other suitable shell material, wherein the capsule is located in the upstream ordownstream plugs42,46.
• 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.

Claims (20)

1. A filter system for a smoking article comprising:

an upstream plug of filtering material;

an impaction filter, the impaction filter comprising at least one plate having at least one orifice; and

a downstream plug of filtering material.

2. The filter system ofclaim 1, further comprising an upstream cavity and a downstream cavity, the upstream cavity provided between the upstream plug of filtering material and the impaction filter, and wherein the downstream cavity is provided between the impaction filter and the downstream plug of filtering material.

3. The filter system ofclaim 1, wherein the upstream plug of filtering material is a cellulose acetate material.

4. The filter system ofclaim 1, wherein the upstream plug of filtering material is a cellulose acetate material with activated carbon throughout.

5. The filter system ofclaim 1, wherein each orifice of the at least one plate has a diameter of about0.4 mm.

6. The filter system ofclaim 1., wherein the impaction filter comprises an upstream plate having a plurality of orifices, the plurality of orifices being equally spaced around an outer perimeter of the first plate, and a downstream plate having a central orifice.

7. The filter system ofclaim 6, wherein the upstream plug of filtering material comprises carbon-on-tow and the downstream plug of filtering material comprises cellulose acetate.

8. The filter system ofclaim 1, further comprising a plug wrap, wherein the plug wrap circumscribes the upstream and downstream plugs of filtering material and the impaction filter.

9. The filter system ofclaim 8, further comprising a plurality of ventilation holes in the plug wrap, wherein the ventilation holes are positioned upstream of the impaction filter.

10. The filter system ofclaim 8, further comprising a plurality of ventilation holes in the plug wrap, wherein the ventilation holes are positioned downstream of the impaction filter.

11. The filter system ofclaim 6, wherein the downstream plate is coated with microencapsulated flavorants.

12. A smoking article comprising:

a tobacco rod; and

a filter system attached to the tobacco rod, the filtering system comprising:

an upstream plug of filtering material;

an impaction filter, the impaction filter comprising at least one plate having at least one orifice; and

a downstream plug of filtering material.

13. The smoking article ofclaim 12, further comprising an upstream cavity and a downstream cavity, the upstream cavity provided between the upstream plug of filtering material and the impaction filter, and wherein the downstream cavity is provided between the impaction filter and the downstream plug of filtering material.

14. The smoking article ofclaim 12, wherein the upstream plug of filtering material comprises cellulose acetate.

15. The smoking article ofclaim 12, wherein the upstream plug of filtering material has cellulose acetate elements with activated carbon throughout.

16. A smoking article comprising:

a tobacco rod; and

a filter system attached to the tobacco rod, the filtering system comprising:

an upstream plug of filtering material;

an impaction filter comprising an upstream plate having a plurality of orifices and a downstream plate having a central orifice; and

a downstream plug of filtering material.

17. The smoking article ofclaim 16, wherein the upstream plug of filtering material comprises carbon-on-tow and the downstream plug of filtering material comprises cellulose acetate.

18. The smoking article ofclaim 16, further comprising tipping paper attaching the tobacco rod to the filter system and a plug wrap, wherein the plug wrap circumscribes the upstream and downstream plugs of filtering material and the impaction filter.

19. The smoking article ofclaim 18, further comprising a plurality of ventilation holes in the plug wrap and/or tipping paper, wherein the ventilation holes are positioned upstream of the impaction filter.

20. The smoking article ofclaim 18, further comprising a plurality of ventilation holes in the plug wrap and/or tipping paper, wherein the ventilation holes are positioned downstream of the impaction filter.

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