MXPA00006697A - Cigarette having reduced sidestream smoke - Google Patents

Abstract

A cigarette (30) includes an ignition element (36) in contact with tobacco (40, 42), surrounded by a composite outer wrapper (38). The outer wrapper (38) is impervious to oxygen causing the tobacco (40, 42) to extinguish between puffs. The ignition element (36), however, has a longer static burn time than the tobacco (40, 42) and remains smoldering between puffs. Upon a subsequent puff, the smoldering ignition element (36) reignites the tobacco (40, 42). One or more initially occluded perforations (34) in the outer layer (38) maintain the uniformity in combustion of the tobacco (40, 42) and the ignition element (36).

Description

CIGARETTE THAT HAS SMOKE REDUCED LATERAL CURRENT BACKGROUND OF THE INVENTION The present invention relates generally to a reduced combustion cigarette of the smoking material during the passive periods between smoking. The invention also relates to a cigarette with regulated combustion of the smoking material between and during each puff. A typical cigarette contains 750 mg to 800 mg of tobacco.

Approximately 20 mg of this tobacco is burned during a puff, while approximately 50 mg is consumed between smokes. The smoke generated by tobacco burned during a smoke is called "mainstream smoke", while the smoke generated between the smokes is called "sidestream smoke". Because a large portion of tobacco is wasted during the passive periods between smoking, practitioners have tried to reduce the combustion of tobacco between these passive periods. U.S. Pat. No. 5,159,940, assigned jointly to Hay ard, et.al., presents a technique to reduce sidestream smoke in a cigarette. As shown in Figure 1, the cigarette 2 disclosed in this patent consists of a tubular member 4 comprising plural sections. A first section is comprised of a heat source 10 composed essentially of carbon. The heat source 10 may also contain catalysts or burn additives to promote combustion. The heat source 10 is secured to a tubular member 4 by a retaining member 16, like metal clips. A second section of the cigarette 2 has a substrate 14, which comprises a load of tobacco mixed with an aerosol precursor, such as glycerin or propylene glycol. A third section of the cigarette 2 comprises an expansion chamber 8. A fourth section comprises a nozzle filter 6, such as a cellulose acetate filter. The above described cigarette works in the following manner. The user turns on the source 10 of heat, whereby the carbonaceous material begins to burn and generate heat. The heat generated by the heat source 10 evaporates the aerosol precursor in the substrate 14 and the gases are generated with a tasty content extracted from the tobacco in the substrate 14. The gases are entrained within the expansion chamber 8, where they expand and cool to form an aerosol 12. The aerosol 1 2 is drawn out through the filter 6 to supply it to the user. This cigarette operates in this way by generating a tasty spray better than burning the tobacco product in a conventional manner. In this way, this cigarette generates little or no sidestream smoke while being consumed. Another cigarette with side stream smoke network is disclosed in U.S. Pat. U U Do not . 5, 105, 835 issued to Drewett et.al. The cigarette exposed inside it also uses a heat source composed of carbonaceous material. The heat source in this device is inserted into a tobacco plug and is in contact with the tobacco. A low permeability wrap surrounds the tobacco plug to restrict the amount of oxygen passing through the wrapper to the downstream tobacco and heat source, thus preventing the tobacco from smoldering freely. The aforementioned cigarette works in the following manner. The consumer turns on the heat source and the smoking material. During a puff, both the heat source and the smoking material are burned to supply the taste to the consumer. However, when the user stops smoking, not enough oxygen reaches the tobacco material to maintain its combustion. Therefore, tobacco stops burning during these passive periods. On the other hand, the coal heat source has enough thermal energy to keep burning. When the user takes another puff of the cigarette, an increased oxygen is fed to the heat source, which increases its speed of combustion and the amount of heat generated by it. This increased heat reignites the tobacco. In this way, this device reduces the sidestream smoke between smokes and also delivers the flavor in a conventional manner by burning the tobacco. The use of low permeability and / or relatively thick outer shells or liners in both of the cigarettes described above generally reduces the oxygen influx into the interior of the cigarettes! Thus, in the exemplary case of Drewett, despite the use of small perforations in the outer envelope, this cigarette can not burn the tobacco uniformly from puff to puff, depending on the strength of the puff and other variables. Accordingly, an exemplary objective of the present invention is to provide a cigarette with reduced sidestream smoke having more uniform and controllable combustion characteristics.

BRIEF DESCRIPTION OF THE INVENTION This and other exemplary objectives are achieved in accordance with the present invention by means of a cigarette that includes an ignition element located within a tobacco plug, which, in turn, is disposed within one or more layers. of cigarette paper. Then, a perforated wrapper is wrapped around the layer (s) of cigarette paper, so that the internal cigarette paper initially blocks the perforations of the outer wrapper and thus oxygen is prevented from reaching the inside of the cigarette. Other materials, such as waxes or films, can be used to block the perforations in addition to the paper layer (s). In a preferred embodiment, the perforated outer shell has a permeability selected to provide sufficient oxygen to the ignition element for maintain its combustion in the passive periods between smokes and also to provide little oxygen to maintain the combustion of the tobacco between smokes. In this way, the tobacco is extinguished (or is subjected to a reduced combustion rate) between smokes, which eliminates or greatly reduces the amount of sidestream smoke generated by the cigarette. When the user takes a cigarette smoke after a passive period, the oxygen is fed to the ignition element which increases its combustion rate and temperature. This, in turn, relights the tobacco. To function in this way, an ignition element is selected that has different thermal characteristics in a low oxygen environment compared to tobacco. In general, the selected ignition element is extinguished less quickly in a low oxygen environment compared to tobacco. In an exemplary embodiment, the ignition element comprises a carbon element inserted in the tobacco plug. D uring the use of the cigarette, the heat generated by the ignition element and the tobacco that undergoes the combustion burns the paper blocking the perforations, so the perforations are exposed and passages are created that allow the oxygen to reach the interior of the cigarette through the outer wrapper. The perforations are "opened" in a successive manner as the embers of the ignition element advance inwardly from the cigarette end of the cigarette. That is, the perforations located at the distal end of the cigarette open first, followed by perforations located successively further in from the distal end. In this way, oxygen is available for the ignition element, even when the burned portion of the ignition element is recessed within the outer envelope. However, initially the perforations located inward of the distal end are closed, so that the air will not be drawn inconveniently through the base of the cigarette. Accordingly, the cigarette of the present invention reduces sidestream smoke while providing uniform and controllable combustion characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages of the present invention will be better understood by reading the following detailed description taken in conjunction with the drawings, in which: Figure 1 shows a device for generating an aerosol flavored according to the prior art; Figure 2 (a) shows a first embodiment of a cigarette according to the present invention; Figure 2 (b) shows a cross section of the cigarette of Figure 2 (a); Figure 3 (a) shows a second embodiment of the cigarette according to the present invention; Figure 3 (b) shows a cross section of the cigarette of Figure 3 (a); Figure 4 shows an exemplary construction of a composite outer wrapper for use in the cigarettes of the present invention; Figure 5 (a) shows an exemplary scheme of the perforations in the outer shell composed in accordance with a first embodiment; Figure 5 (b) shows an exemplary scheme of the perforations in the outer shell composed in accordance with a second embodiment; and Figure 5 (c) shows an exemplary scheme of the perforations in the outer shell composed in accordance with a third embodiment.

DETAILED DESCRIPTION In the following description, for purposes of explanation and without limitation, the specific details are mentioned below to provide a complete understanding of the invention. However, it will be apparent to those skilled in the art that the present invention can be practiced in other embodiments that depart from these specific details. In other cases, detailed descriptions of well-known methods and devices are omitted so as not to confuse the description of the present invention with unnecessary details. In the figures, the equal numbers indicate the equal parts. Figure 2 (a) shows a perspective view of a cigarette 30 in accordance with a first embodiment of the present invention and Figure 2 (b) shows a cross-sectional view of this cigarette 30. In accordance with the exemplary embodiments, the cigarette 30 is approximately 83 mm long and contains four main sections. A first section 41 includes the tobacco 40 (or a tobacco-based material) and an ignition element 36 in contact with the tobacco 40. This section is attached to a second section 42, which only contains tobacco. The next section 44 comprises a hollow tube, such as a tube of cellulose acetate fiber. Finally, section 44 is attached to a filter section 46, which may comprise a conventional filter section (eg, comprising a cellulose acetate filter). According to the exemplary embodiments, the first section 41 is approximately 21 mm in length, the second section 42 is approximately 10 mm in length, the third section 44 is approximately 22 mm in length and the last section 46 is approximately 30 mm long. Carbon or carbon-based compounds are generally the appropriate materials to be used to form the ignition element 36. Salts such as carbonates and / or potassium and / or sodium acetates can be used to modify the initial combustion temperatures of the coal-based ignition element 36. More generally, any material or compound can be used to form the ignition element 36, since this element is less rapidly extinguished in a low oxygen environment compared to the tobacco 40. This can be matched with the ignition element 36 having a "static burn time" longer compared to tobacco 40 in a low oxygen environment. In another embodiment, for example, the ignition element 36 may comprise a tobacco plug with a longer static burn time than the tobacco material 40 surrounding it. This can be achieved by treating the tobacco materials with some combustion retardants and / or promoters to achieve the desired burn rate between the internal and external tobacco sections. With reference to both Figures, 2 (a) and 2 (b), the ignition element 36 in accordance with the exemplary embodiment comprises a cylindrical rod that extends or is essentially axially coextensive with the length of the first section. (for example, approximately 21 mm). The ignition element 36 is approximately 50 mg by weight and has a diameter of approximately 3 mm. The axis of the ignition element 36 coincides with the axis of the cigarette 30. However, experienced persons will appreciate that the ignition element 36 can be formed with different silhouettes. For example, the ignition element 36 may comprise a plurality of smaller rods located within the first section 41 or may comprise one or more strips of material located within the first section 41.

One or more layers of cigarette paper (generally designated as paper 32) cover the different sections containing the tobacco 40. The cigarette paper 32 may comprise any conventional cigarette paper or may comprise reduced sidestream cigarette paper. as a high-density weight paper containing calcium carbonate (for example, at approximately 53 g / m2). As will be appreciated by those skilled in the art, other layers of paper or combinations may be used to cover the different sections 41, 42, 44 and 46. Then, a composite outer wrap 38 is wrapped around the inner paper 32 for cigarette . As shown in Figures 2 (a) and 2 (b), the outer composite envelope 38 preferably covers the tobacco in sections 41 and 42. More specifically, the outer envelope 38 composed in this embodiment goes from the exposed distal tip of section 41 up to one millimeter beyond the end of section 42. However, in the cigarette 31 shown in Figs. 3 (a) and 3 (b), the composite external envelope 38 begins approximately 1 mm to 5 mm from the exposed tip of section 41. Leaving a section of the tip exposed allows oxygen to penetrate faster into the cigarette pin. This allows an initial ignition of the cigarette easier. It should be noted that Figures 2 (a) and 3 (a) show the outer envelope 38 partially removed from the cigarette (30, 31) to better illustrate the composite outer envelope 38. However, during use, the composite outer wrap 38 is completely wrapped around the cigarette (30, 31) As shown in Figure 4, in the preferred embodiment, the composite outer envelope 38 comprises a three-layer material formed of a metal foil layer 52 interposed between two layers (50, 54) of low sidestream paper ( as a paper containing a load of calcium carbonate at approximately 53 gm / m2) or another type of paper. In accordance with preferred embodiments, the metal sheet is formed of an aluminum foil sheet with a thickness of about 0.00025 to 0.002 inches, although thinner or thicker sheets may be used. The three layers can be laminated together with a suitable adhesive, such as polyvinyl acetate adhesive. Sheet 52 of metal works for three main purposes.

First, the sheet 52 is essentially impermeable to oxygen. In this way, the sheet 52 creates a low oxygen environment within the cigarette between the puffs by blocking the flow of oxygen within the cigarette through the side walls of the cigarette. Second, the sheet removes and dissipates the heat of the ignition element 36 and of the tobacco 40. This promotes the rapid reduction of the rate of combustion of the tobacco 40 after smoking. Third, the sheet 52 protects the outer paper layer 50 of the ignition element 36 and helps reduce the carbonization of the outer paper layer 50 caused by the heat generated by the ignition element 36. The reduction in carbonization is proportional to the thickness of the sheet 52. The relatively thick sheets 52 will produce minimal carbonization of the paper layer 50. This results in a minimization of discoloration of the paper layer 50. Thinner layers will produce some discoloration (ie, tanning or blackening) of the paper layer 50. The degree of carbonization is also directly proportional to the number of perforations in the envelope (it will be described in more detail below). In other embodiments, instead of a three-layer envelope, an outer laminated envelope comprising a single layer of paper and a single sheet layer or simply a single layer of sheet or other material may be used. In addition, other materials can be used to form the outer shell in addition to the metal sheet, as ceramic-based layers or other essentially non-combustible materials. Referring again to Figures 2 (a) and 3 (a), the composite outer envelope 38 preferably includes a number of perforations 34. In the exemplary embodiments shown in these figures, the perforations 34 comprise a plurality of small openings These perforations 34 provide passageways within the interior of the cigarette to allow a limited amount of oxygen to reach the tobacco 40 lying at the bottom and the ignition source 46 through the sides of the cigarette. However, the cigarette paper 32 lies between the wrapper 38 and the tobacco 40 and therefore, initially blocks the passages. After a series of puffs, the heat generated by the ignition element 36 and the tobacco 40 burns the cigarette paper 32 below the perforations 34, so that the passages are opened. More specifically, the perforations 34 are "opened" in succession as the embers of the ignition element and the portion of the tobacco bed undergoing combustion advances from the distal end of the cigarette towards the end of the nozzle of the cigarette. That is, the perforations located at the distal end of the cigarette open first, followed successively by the perforations located further in from the distal end. In this way, oxygen is available for the ignition element even when the combustion portion of the ignition element is recessed within the outer shell. However, initially, the perforations located inward from the distal end of the cigarette close, so that the air will not undesirably creep through the base of the cigarette. In accordance with this, the cigarette of the present invention reduces side stream smoke while providing uniform combustion characteristics. The size and position of the perforations 34 can be selected to achieve different burn rates. Generally, the oxygen influx can be evenly distributed to provide a uniform burn rate by using many relatively small perforations or by using a plurality of rows of small perforations with different dimensions. For example, a plurality of uniformly dispersed square perforations with dimensions of approximately 0.5 mm by 0.5 mm can be used. In an exemplary embodiment, the perforations begin approximately 1 mm from the edge located further to the left of the envelope 38 (with reference to the graphic illustrations of Figures 2 (a) and 3 (a)) and end at approximately 7 mm 15 mm from the edge located to the left of the envelope 38. Preferably, the ignition element 36 extends at least a short distance beyond the end of the perforations 34. The perforations 34 are shown with a shape essentially square, but other shapes can be used. The perforations 34 may have a circular or oval shape, a slot-like shape or other shapes, or different shapes may be used in the same envelope in different regions. In addition, the perforations 34 are illustrated in orderly rows, but the perforations can be dispersed on the surface of the external envelope 38 composed of other patterns or randomly dispersed on the surface. Figure 5 (a) illustrates the envelope 38 of Figures 2 (a), 2 (b), 3 (a) and 3 (b), which include a plurality of perforations 34. In an exemplary embodiment, the perforations begin at approximately 1 mm from the distal or "upper" end of the sheath 38 and end approximately 7 mm at 15 mm from the top of the envelope 38. These perforations can have any desired dimension as mentioned above. For example, square perforations having dimensions of 0.5 mm by 0.5 mm can be used, where each perforation is separated from a neighboring perforation by a distance of 0.5 mm. However, these dimensions are exemplary and those skilled in the art will appreciate that other dimensions are also appropriate. Figure 5 (b) shows other modalities, which include different rows of small perforations with different dimensions. As shown therein, the perforations 71 comprise a first section of perforations with smaller openings ("s") than the perforations 73 comprising a second section of perforations. For example, perforations 71 may comprise square openings with dimensions of 0.5 mm by 0.5 mm, while perforations 73 may comprise square openings with dimensions of 1.0 mm by 1.0 mm. These larger perforations 73 supply more oxygen to those portions of section 41 that are located away from the exposed tip of the cigarette. These larger perforations 73 may be convenient for improving the oxygen supply to more recessed portions of the ignition element 36. Portions of section 41 located closer to the exposed tip of the cigarette receive more oxygen from the exposed tip and therefore, smaller perforations 71 will be sufficient in these portions. Only two perforation graduations are shown (71, 73). However, persons skilled in the art will appreciate that three or more different s of perforations can be used. Figure 5 (c) shows another embodiment of the outer envelope 38 composed of a different array of perforations formed therein. More specifically, the composite external envelope 38 includes the same array of perforations 34 shown in Figure 5 (a). Additionally, the composite outer wrap 38 also includes a series of larger perforations 64 behind the tip of the cigarette. These larger perforations 64 are located approximately 15 mm from the tip of the cigarette. With reference to Figure 2 (a), these larger perforations 64 are located approximately in a position 43 designated "x". A complementary film or wax (or other material) can cover these perforations 64. As mentioned above, when the outer wrap 38 is wrapped around the internal paper of the cigarette, the perforations of the outer wrap are obstructed by the inner paper. This prevents, first of all, that the oxygen reaches the interior of the cigarette through the perforations. During use, the ignition element and the tobacco material around it, get enough thermal energy to burn the paper from below the perforations. Typically, the perforations located closer to the burned end of the ignition element and the surrounding tobacco (i.e., the portion of the cigarette with the highest thermal energy) will open first. In this way, the perforations located closer to the distal end of the envelope will typically open first, followed successively by the perforations further in as the charred carbon from the ignition element advances towards the inside of the envelope. However, it should be noted that the perforations do not need to be opened in the sequence described above. Namely, the perforations that are displaced axially from the embers can be opened. For example, if the ignition element and the surrounding tobacco acquire sufficient thermal energy, the larger perforations 64 shown in Figure 5 (c) can be opened, although the embers are located towards the distal end of the cigarette. By opening these larger perforations 64, air is drawn into the cigarette from the base of the cigarette. During entrainment, therefore, a certain amount of air will flow through the cigarette behind the partially burnt tobacco plug. This will decrease the oxygen flow that passes axially through the cigarette and the ignited ignition element. This results in the final extinction of the cigarette. Alternatively, smaller perforations 64 can be used, which will serve to reduce the burning rate of the cigarette, rather than completely extinguish the cigarette. The sealing paper paper 32 has been described above as blocking the perforations from the bottom of the outer layer 38. However, the paper 32 of the cigarette blocking the perforations can be located on top of the outer envelope 38. Alternatively, the perforations in the outer layer 38 can be blocked both from the inner surface and from the outer surface of the outer layer 38. Finally, instead of the paper 32 of the cigarette or complementary to the paper 32 of the cigarette, the blockages can be formed by blocking the perforations in the outer wrapping layer when filling the perforations with some material that burns or melts when exposed to the cigarette. the thermal energy of the ignition element. For example, a cellulose or wax type material can be formed in the perforations. Having described the structural components of the cigarette, the operating characteristics of the device will now be described in greater detail. During use, a consumer turns on (30, 31) with a cigarette lighter or other appropriate device and simultaneously smokes the cigarette. At this point, the portions of the paper 32 of the cigarette below the perforations 34 are intact and therefore, the entrained air inside the cigarette originates first from the exposed open end of the cigarette. This facilitates turning on the ignition source 46 and the tobacco 40. After the consumer's initial smoking, the tobacco can continue to burn without help for a short time due to the close proximity of the open end of the cigarette and the availability of oxygen from the end. open. In this aspect, the cigarette 31 shown in Figures 3 (a) and 3 (b) will burn longer without assistance than the cigarette 30 shown in Figures 2 (a) and 2 (b) due to the length of the paper 32. of the cigarette exposed near the tip. The oxygen availability decreases, however, as the carbon from the ignition element advances down the cigarette below the outer composite envelope 38, which is essentially impermeable to oxygen and other gases. This lack of oxygen will reduce and eventually extinguish combustion in the tobacco 40. This is accelerated by the use of the aluminum sheet 52 (of Figure 4), which draws thermal energy rapidly away from the tobacco 40. However, the composition with The carbon base of the ignition element 36 allows the ignition element 36 to keep burning during the passive periods between puffs. Alternatively, the carbon-based material may not actually be burning during the passive periods, but simply retain enough thermal energy to relight the tobacco 40 when the consumer takes another puff of the cigarette. This can be achieved by selecting the composition, mass and dimensions of the ignition element 36 so that its temperature does not fall below its re-ignition temperature, (ie, approximately 200 ° -300 ° C in an exemplary embodiment). As a frame of reference, the ignition element 36 can raise its temperatures above about 700 ° C -900 ° C during a smoking in an exemplary embodiment.

When the user returns to smoking the cigarette, the air flows axially through the cigarette, supplying oxygen to the ignition element 36 and to the tobacco 40. This oxygen influx increases the combustion rate of the ignition element 36, which in turn , relight the tobacco 40. When the user finishes smoking, the tobacco 40 is extinguished again. During the first initial puffs, the ignition element 36 generates sufficient heat to burn the paper 32 of the cigarette lying beneath at least the most distant section of the perforations 34 in the composite outer envelope 38. These open passages provide additional oxygen to the ignition element 36 between puffs and during puffs, and therefore allow the ignition element 36 to remain on as the carbon advances further into the interior of the cigarette. If the ignition element acquires sufficient thermal energy, the perforations located axially displaced from the embers can be opened. For example, if the ignition element acquires sufficient thermal energy, the larger perforations 64 shown in Figure 5 (c) can be opened, even when the embers of the ignition element are located near the distal end of the cigarette. With the opening of these larger perforations 64, air is drawn into the cigarette from the base portion of the section 41 of the cigarette. Therefore, during entrainment, a certain amount of air will flow through the cigarette behind the plug of the partially burned tobacco. This will decrease the flow of oxygen passing axially through the cigarette and the ignition element 36 burned. This results in the final extinction of the cigarette for the relatively larger perforations 64. The larger perforations 64 can also be opened when the embers of the ignition element 36 advance sufficiently close to the larger perforations 64 to burn the paper 32 located below the perforations. Because tobacco 40 is extinguished between each puff, very little tobacco is wasted 40. In one embodiment, 250 mg of tobacco can be used to provide eight or nine puffs, whereas a conventional cigarette requires 700 to 800 mg of tobacco to provide the same number of smokes. In addition, the use of an array of perforations in the composite outer sheath 38 provides a uniform combustion of the underlying ignition element 36 and tobacco 40. The larger perforations 64 near the rear of section 41 open when the ignition element acquires sufficient thermal energy to provide greater control of the flow rate. The exemplary embodiments described above are intended to be illustrative in all respects, rather than restrictive with respect to the present invention. In this way, the present invention is capable of undergoing many variations in the detailed structuring that can be derived from the description contained therein by a person skilled in the art. All of these variations and modifications are considered within the scope and spirit of the present invention as defined by the following claims. For example, although the above description has been delimited within the context of cigarettes, the invention extends to any article for smoking. In addition, section 41 of the smoking material is not limited to tobacco, but may comprise any substrate containing flavor released by combustion.

Claims (31)

1. CLAIMS 1. A smoking article that has a longitudinal axis, with reduced sidestream smoke between each puff; which comprises: a plug of smoking material; an ignition element that is coextensive axially with the plug of the smoking material and is in contact with the smoking material, the smoking material is extinguished more rapidly in a low oxygen environment compared to the ignition element; a first layer of material formed around the smoking material and the ignition element; and a second layer of material formed adjacent the first layer, wherein the second layer reduces the combustion of the smoking material between each puff, wherein the first layer is more combustible than the second layer when exposed to the thermal energy generated by the second layer. the ignition element and the smoking material.
2. 2. The smoking article according to claim 1, wherein the smoking material includes a tobacco-based material.
3. 3. The smoking article according to any of the preceding claims, wherein the ignition element comprises a carbon-based material.
4. 4. The smoking material according to claim 1, wherein the ignition element has an essentially cylindrical shape and is aligned concentrically with the longitudinal axis of the smoking article.
5. 5. The article for smoking with any of the preceding claims, wherein the ignition element is inserted into the stopper of the smoking material.
6. 6. The smoking article of any of the preceding claims, wherein the ignition element extends axially along the length of the smoking material.
7. The smoking article according to any of the preceding claims, wherein the ignition element makes direct contact with the smoking material at multiple points axially displaced on the surface of the ignition element.
8. 8. The smoking article according to any of the preceding claims, wherein the second layer comprises a composite layer containing multiple layers.
9. The smoking article according to claim 8, wherein the composite layer includes a sheet metal layer.
10. 10. The smoking article according to claim 9, wherein the composite layer includes a layer of paper laminated with the sheet metal layer.
11. The smoking article according to claim 9, wherein the layer includes two layers of paper laminated on both sides of the sheet metal layer.
12. 12. The smoking article according to any of the preceding claims, wherein the second layer extends towards an end of the article in which the smoking material is exposed.
13. 13. The smoking article according to any of claims 1 to 11, wherein the second layer extends inwardly at a non-zero distance L from the end of the article in which the smoking material is exposed.
14. 14. The smoking article according to claim 13, wherein the second layer extends inwardly at about 1 mm to 5 mm from the end.
15. 15. The smoking article according to any of the preceding claims, which further includes at least one perforation in the second layer.
16. 16. The smoking article according to claim 15, wherein at least one perforation comprises at least one perforation of a first size and at least one perforation of a second size that is larger than the first size.
17. The smoking article according to claim 16, wherein at least one perforation of a first size is located closer to an open end of the smoking article than at least one perforation of a second size.
18. 18. The article for smoking according to any of claims 15 to 17, wherein at least one perforation is blocked by the first layer of material before using the article.
19. The smoking article according to claim 18, wherein at least the portions of the first layer of material located below at least one perforation are sufficiently combustible when exposed to the heat generated by the ignition element and the material to smoke, so that the portions burn during the use of the article, leaving the second layer intact.
20. 20. The smoking article according to the claims 15 to 19, wherein at least one perforation in the second layer comprises a plurality of perforations arranged in a pattern.
21. 21. A smoking article having a longitudinal axis with reduced sidestream smoke between each puff, which comprises: a plug of smoking material; an ignition element that is coaxially extended with the plug of smoking material and is in contact with the smoking material, the smoking material is extinguished more rapidly in a low oxygen environment compared to the ignition element; a wrap formed around the smoking material and the ignition element, wherein the wrap reduces the combustion of the smoking material between each puff, wherein the wrap includes at least one bore having an opening blocked by an obstruction.
22. 22. The. smoking article according to claim 21, wherein the ignition element is inserted into the plug of smoking material.
23. 23. The smoking article according to claim 21 or claim 22, wherein the obstruction comprises a first layer of material disposed under or on top of the envelope.
24. 24. The smoking article according to any of claims 21 to 23, wherein the obstruction comprises a fuel-filled material that blocks the opening.
25. 25. The smoking article according to any of claims 21 to 24, wherein at least one perforation comprises a plurality of perforations.
26. 26. The smoking article according to claim 25, wherein the plurality of perforations comprises a first plurality of perforations with openings having a first dimension and a second plurality of perforations with openings having a second dimension, wherein the openings with the first dimension they are smaller than the openings with the second dimension.
27. 27. The smoking article according to claim 26, wherein the first plurality of perforations is located closer to an open end of the cigarette compared to the second plurality of perforations.
28. 28. The smoking article according to claims 21 to 27, wherein the smoking material is located in a smoking material section of the smoking article having a base end and an open end, and at least one piercing It is located near the base end.
29. 29. The smoking article according to claim 28, wherein the smoking article is structured in such a way that it will be extinguished when the obstruction is removed from at least one perforation, even if the unburned smoking material remains in between. at least one piercing and the open end.
30. 30. The smoking article according to claim 28 or claim 29, further comprising additional perforations located closer to the open end compared to at least one perforation located near the base end, wherein the additional perforations have sizes smaller compared to the at least one perforation located closer to the base end.
31. 31. A smoking article comprising: smoking material; an ignition element to supply thermal energy for the smoking material, the smoking material extinguishes more rapidly in a low oxygen environment compared to the ignition element; a sheet wrap formed around the smoking material and the ignition element, wherein the wrap reduces combustion of the smoking material between each puff, wherein the jacket includes perforations along the ignition element having openings that are blocked by the obstructions