KR20210143311A - smoking articles - Google Patents

Abstract

A smoking article, the smoking article comprising tobacco material wrapped in a paper wrapper to form a tobacco rod, the paper wrapper having a diffusivity of between about 0.1 cm/s and 0.5 cm/s and a permeability of less than about 15 CU; Described and described are methods of making a smoking article.

Description

smoking articles

The present invention relates to smoking articles and methods of making smoking articles.

Cigarettes and other combustible smoking articles produce smoke that is inhaled by a user. The tobacco is wrapped in a paper wrapper to form a tobacco rod, and the filter may be connected to the tobacco rod. Filters may be configured to modify properties of smoke produced by a smoking article, for example, by adding a flavoring agent to the smoke produced by the smoking article.

According to embodiments of a first aspect of the present invention, there is provided a smoking article comprising tobacco material wrapped in a paper wrapper to form a tobacco rod, wherein the paper wrapper has a thickness of between about 0.1 cm/s and 0.5 cm/s. diffusivity and permeability of less than about 15 CU.

The paper wrapper may have a diffusivity of about 0.1 cm/s to 0.3 cm/s.

The paper wrapper may have a diffusivity of about 0.15 to about 0.25, about 0.15 to about 0.20, or about 0.17 to about 0.22 cm/s.

The paper wrapper may have a permeability of less than about 15 CU over at least 50% of the surface area of the paper wrapper.

The paper wrapper may have a permeability of about 4 CUs to about 12 CUs.

The paper wrapper may have a permeability of about 4 to about 12 CUs over at least 90% of the surface area of the paper wrapper.

The paper wrapper may have a permeability over at least 90% of the surface area of the paper wrapper, less than about 10 CUs, or from about 3 to about 7 CUs.

The smoking article may include a filter.

The pressure drop across the filter may be between about 40 mm WG and 180 mm WG.

The filter may include a ventilation area.

The ventilation zone may provide 40% to 90% ventilation.

The filter may include a filter material having a denier per filament of between 2.5 and 9.

The filter may include a filter material having a total denier of 10,000 to 32,000.

The paper wrapper may have a basis weight of 24 to 36 g/m ^{2 .}

The paper wrapper may have a basis weight of 27 to 32 g/m ^{2 .}

The paper wrapper may have a basis weight of about 28 g/m ^{2 .}

The paper wrapper may have a basis weight of about 32 g/m ^{2 .}

The paper wrapper may include less than 30 weight percent filler of the paper wrapper.

The paper wrapper may comprise from 15% to 25% by weight of filler.

The filler may include calcium carbonate.

The paper wrapper may have an opacity of 60% to 80%, or 68% to 80%.

The paper wrapper may comprise less than 4% by weight of the burning additive of the paper wrapper.

The paper wrapper may include about 1% by weight of the combustion additive.

The combustion additive may be sodium citrate, potassium citrate, or a mixture of sodium and potassium citrate.

According to embodiments of the second aspect of the present invention, forming a tobacco rod by wrapping tobacco material in a paper wrapper having a diffusivity of about 0.1 cm/s to 0.5 cm/s and a permeability of less than about 15 CUs. A method of making a smoking article is provided, comprising:

The method may further comprise attaching a filter to the tobacco rod.

The method may further comprise providing a ventilation zone for facilitating ventilation into the filter.

The paper wrapper may have a diffusivity of about 0.1 cm/s to 0.3 cm/s.

The paper wrapper may have a permeability of about 4 to about 12 CUs over at least 50% of the surface area of the wrapper.

The paper wrapper may have a permeability of about 4 to about 12 CUs over at least 90% of the surface area of the wrapper.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings.
1 illustrates a smoking article in accordance with one embodiment.
2 illustrates a smoking article according to a further embodiment, having a filter comprising a capsule;
3 illustrates a smoking article according to a further embodiment, having a filter comprising a tubular element;
4 illustrates a smoking article according to a further embodiment, having a filter comprising a tubular element and an adsorbent material dispersed within the filter material.

As used herein, the term “smoking article” refers to combustible smoking articles and components thereof such as cigarets, cigarillos, cigars, and roll-your- own) Cigarettes (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco substitutes or other smokeable material).

The filters described herein may be provided to users as an integral component of the smoking article or as a separate component separate from the smoking article. When provided separately, the filter units and smoking articles may be packaged separately or packaged together as a kit of parts.

Smoking articles, such as cigarets and formats thereof, are often named according to the following cigarette length: "regular" (usually within the range of 68-75 mm, e.g., about 68 mm to about 72 mm) ), "short" or "mini" (less than 68 mm), "king-size" (usually within the range of 75 - 91 mm, e.g., from about 79 mm to about 88 mm) ), "long" or "super-king" (usually within the range of 91 - 105 mm, e.g., about 94 mm to about 101 mm) and "ultra-long" (usually within the range of about 110 mm to about 121 mm).

They are also named according to the cigaret circumference: "regular" (about 23 - 25 mm), "wide" (greater than 25 mm), "slim" (about 22 - 23 mm), "demi- "demi-slim" (about 19 - 22 mm), "super-slim" (about 16 - 19 mm), and "micro-slim" (less than about 16 mm) . Thus, for example, a king-sized, super-slim format cigarette would have a length of about 83 mm and a circumference of about 17 mm. Cigarettes in the regular king-size format have a circumference of 23 to 25 mm and an overall length of 75 to 91 mm.

Each format can be created with filters of different lengths, with smaller filters generally being used with formats of smaller lengths and circumferences. Typically, the filter length will be about 15 mm associated with short regular formats to 30 mm associated with ultra-long super-slim formats. The tipping paper will have a length eg 3 to 10 mm longer than the filter so that the tipping paper covers the filter and overlaps the tobacco rod to connect the filter to the tobacco rod.

Smoking articles and filters described herein may be manufactured in any of the formats above, but are not limited to these.

The filter material forming the filters described herein may include cellulose acetate fiber tow. The filter material may also include other materials used to form the fibers such as polyvinyl alcohol (PVOH), polylactic acid (PLA), polycaprolactone (PCL), poly( 1-4 butanediol succinate) (PBS), poly(butylene adipate-co-terephthalate) (PBAT), starch-based materials, paper, cotton ( cotton), aliphatic polyester materials, and polysaccharide polymers, or combinations thereof. The filter material may be plasticized with a suitable plasticizer for the filter material, such as triacetin, where the filter material is cellulose acetate tow, or it may be non-plasticized. The tow used to produce the filter unit or other filter component may have any suitable dimensions such as a 'Y' shape or other cross-section, filament denier values of 2.5 to 15 denier per filament, such as 3.0 to 9.0 denier per filament, and 10,000 Fibers having total denier values of from 15,000 to 45,000 may be used, for example from 15,000 to 50,000.

As used herein, the terms “flavour” and “flavoring agent” refer to ingredients that can be used to create a desired taste or aroma in a product for adult consumers, where local regulations permit. These are extracts (eg, licorice, hydrangea, Japanese white bark magnolia leaf), chamomile, fenugreek, clove, menthol. , Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon ), scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia (cassia), caraway, cognac, jasmine, ylang-ylang, sage, fennel, pepper, ginger, anise anise), coriander, coffee, or mint oil from any species of the genus Mentha), flavor enhancers, bitterness receptor site blockers, sensory receptor site activation Sensorial receptor site activators or stimulants, sugars and/or sugar substitutes (eg sucralose, acesulfame potassium, aspartame, saccharine, cycla) cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other substances or additives, such as , charcoal, chlorophyll, minerals, botanicals, or breath freshening agents). These may be counterfeit, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example as an oil, liquid or powder.

In the drawings described herein, like reference numbers are used to illustrate equivalent features, articles, or components.

1 is a side cross-sectional view of a smoking article 1 . A smoking article 1 , which in this example is a cigarette, has a mouth end 1a arranged to be placed in a user's mouth when smoking and a lit end 1b arranged to light up when smoking. Tobacco material 2 is wrapped in a paper wrapper 3 to form a tobacco rod.

In some examples, the smoking article does not include a filter. In other examples, the filter 4 is connected to the tobacco rod by a tipping paper 5 . The filter 4 is wrapped in a plug wrap 6 . A ventilation area 7 may be provided to allow outside air into the filter 4 during use. The ventilation area may be provided as a series of perforations that pass through the tipping paper 5 and plug wrap 6 into the filter 4 .

The paper wrapper 3 has a diffusivity of about 0.1 cm/s to 0.5 cm/s. In some examples, the paper wrapper 3 has a diffusivity of about 0.1 cm/s to about 0.3 cm/s.

In some examples, the paper wrapper 3 has a diffusivity of less than about 0.30 cm/s. In some examples, the paper wrapper 3 has a diffusivity of less than about 0.25 cm/s. In some examples, the paper wrapper 3 has a diffusivity of 0.15 to 0.2 cm/s. Advantageously, such levels of diffusivity have been found to be particularly effective in providing smoking articles, such as cigarettes, having an increased number of puffs and more consistent delivery per puff. Such smoking articles have also been found to pass low ignition propensity tests known in the art, exhibiting acceptable rates of free air self-extinguishment. Free air self-extinguishing is the property of a smoking article to self-extinguish when held in free air (ie, rather than being placed on a substrate), which is undesirable from a consumer's point of view. In some examples, the paper wrapper has a diffusivity of 0.10 to 0.3 cm/s, 0.15 to 0.25 cm/s, 0.15 to 0.20 cm/s, or 0.17 to 0.22 cm/s.

The paper wrapper 3 has a low permeability, in this example less than about 15 Coresta Units (CU). For example, the paper wrapper may have a permeability of less than about 15 CU over at least 50% of the surface area of the paper wrapper or over at least 75% or 90% of the surface area of the paper wrapper.

In some examples, the paper wrapper 3 has a permeability of about 4 to about 12 CUs. In some examples, the paper wrapper 3 has a permeability of about 4 to about 12 CUs over at least 90% of the surface area.

In some examples, the paper wrapper 3 has less than 10 Coresta Units (CU), or in each case from about 3 to about 7 CUs over at least 50% or more preferably 75% or 90% of the surface area of the paper wrapper. have permeability.

In the use of the smoking articles described herein, the paper wrapper 3 having low diffusivity and low permeability ranges as described compared to smoking articles having paper wrappers having higher levels of diffusivity and permeability, Reduces the amount of oxygen drawn into the tobacco rod when the smoking article is smoked. Reducing the amount of oxygen drawn into the tobacco rod has the effect of causing the tobacco 2 to burn at a slower rate between puffs, thus increasing the length of time the tobacco rod is burned, demonstrating a longer smoking experience. do.

In some examples, the entire paper wrapper 3 has low diffusivity and low permeability ranges as defined herein.

In some examples, the diffusivity of the paper wrapper 3 may be uniform along the length of the tobacco rod when the paper wrapper 3 is wrapped around the tobacco rod. Additionally or alternatively, the diffusivity of the paper wrapper 3 may be uniform around the entire circumference of the tobacco rod. The paper wrapper 3 may include some areas with higher or lower diffusivity. In some examples, at least 50% of the paper wrapper is provided with a low diffusivity, for example less than 0.3 cm/s. In some examples, greater than 75%, or 80% or about 100% of the wrapper is provided with a low diffusivity, such as less than 0.3 cm/s or less than 0.25 cm/s. Alternatively or additionally, at least 50% of the paper wrapper may be provided with a low permeability, for example less than 15 CU. In some examples, greater than 80%, 90%, or about 100% of the wrapper is provided with a low permeability, eg, less than 15 CU, as described. The paper wrapper may have one or more distinct zones with low permeability and low diffusivity. In some examples, the entire paper wrapper is provided with uniform low diffusivity and low permeability within the ranges described herein. Providing an overall paper wrapper having low diffusivity and low permeability provides free of charge of the smoking article for the duration of smoking as compared to providing two or more distinct regions of the smoking article having low diffusivity and low permeability. Reduces variability in air self-extinguishing properties.

The filter 4 may have a substantially cylindrical shape. The filter 4 may have a length of 6 mm to 30 mm, for example 7 mm to 20 mm. In one example, the filter 4 is 18 mm long.

The tobacco rod may also be of a substantially cylindrical shape, having an outer diameter substantially equal to the outer diameter of the filter 4 when a filter is provided. The tobacco rod comprises a substantially cylindrical core of packed tobacco material 2 wrapped in a paper wrapper 3 . Tobacco material 2 may comprise a blend of shredded tobacco, and may also comprise reconstituted tobacco material. The paper wrapper 3 extends around the circumference of the tobacco rod and along its length to form a wrapped tobacco rod. The end faces of the tobacco rod are left open to allow gas flow to pass axially through the rod.

In some embodiments, the tobacco rod comprises tobacco having a net weight based on the size and type of smoking article. For example, the cigarette weight may be a standard weight corresponding to a conventional smoking article of the same size. In some embodiments, the cigarette weight may be reduced as compared to a conventional smoking article of the same size. The cigarette weight may be selected based on the desired properties of the smoking article. A lower cigarette weight may be associated with a reduction in staining of the paper wrapper. Also, lower cigarette weight may be associated with a decrease in CO and tar levels. However, lower cigarette weight may also be associated with a decrease in the number of puffs. Thus, depending on the properties of the smoking article to be achieved, the tobacco weight may be selected.

In some examples, the smoking article may be a smoking article having a length of 90 mm and a circumference of 21 mm. The net tobacco weight may be, for example, 510 mg. In other examples, the smoking article may have a reduced tobacco weight of 480 mg. A smoking article with a reduced tobacco weight of 480 mg may contain lower levels of CO and tar and may experience lower levels of contamination on the paper wrapper. However, the number of puffs of a smoking article having a reduced tobacco weight of 480 mg may have a lower number of puffs when smoked by a user as compared to a comparable smoking article having a net tobacco weight of 480 mg.

In other examples, a smoking article having a length of about 90 mm and a circumference of about 21 mm may comprise a tobacco weight of 490 mg. Alternatively, the smoking article may comprise a reduced tobacco weight of about 460 mg.

In other examples, a smoking article having a length of about 90 mm and a circumference of about 23 mm may comprise a tobacco weight of about 630 mg. Alternatively, the smoking article may comprise a reduced tobacco weight of about 560 mg.

This property of the resulting smoking article, for example, by selecting a lower cigarette weight to reduce contamination and CO and tar levels, or by selecting a higher cigarette weight to increase the number of puffs obtainable upon smoking. It will be apparent to those skilled in the art that the cigarette weight may be selected based on these factors.

During use in which the smoking article 1 is smoked by the user, air is drawn through the lit tobacco rod to provide smoke to the user. In embodiments that include a filter, smoke is also drawn through the filter to remove some particulate material from the smoke prior to being provided to the user. In embodiments comprising a ventilated filter, air is drawn through the ventilation area 7 of the filter 4 during use to dilute the smoke delivered to the user through the filter 4 . .

In some examples, the ventilation area 7 comprises perforations in the filter tipping paper 5 and the plug wrap 6 . In some examples, the ventilation area 7 comprises areas embossed in the filter tipping paper 5 and/or the plug wrap 6 . Alternatively, at least one of the tipping paper 5 and the plug wrap 6 may be provided as a porous material (eg, having a porosity greater than 200 Coresta Units (CU)), allowing air into the filter 4 . do. The filter 4 may be vented by vent channels formed using laser or electrostatic drilling techniques. The ventilation area 7 may be provided as any part of the filter 4 , for example at least 12 mm from the mouth end 1a of the smoking article. In examples with multiple filter sections or segments, the ventilation area may be provided, for example, with the filter section or segment adjacent the tobacco rod.

In some examples, the pressure drop across the filter 4 is between 40 mm WG and 180 mm WG. The pressure drop of the filter can be selected according to the desired properties of the product. In some examples, the pressure drop across the filter is between 70 mmWG and 180 mmWG. In some examples, the pressure drop across the filter is between 130 mmWG and 180 mmWG. In some examples, the pressure drop across the filter is between 140 mmWG and 180 mmWG. In some examples, the pressure drop across the filter is between 70 mmWG and 100 mmWG. In some examples, the pressure drop across the filter is between 85 mmWG and 100 mmWG.

In some examples, the filter is not provided with a ventilation region. In other examples, the filter is provided with a ventilation region. The ventilation region 7 of the filter 4 may provide ventilation between 40% and 90% when the smoking article is smoked during use. For example, the ventilation region may provide between 55% and 90% ventilation. In some examples, the ventilation region provides between 55% and 85% ventilation. In some examples, the ventilation region provides between 60% and 75% ventilation. In some examples, the ventilation region provides 65% to 75% ventilation.

By varying the levels of ventilation and pressure drop across the filter, the levels of CO and tar delivered to the user can be altered. A higher level of ventilation across the filter allows the levels of tar and CO to be reduced when using a cigarette paper with low diffusivity and low permeability as described herein. Higher levels of ventilation also increase the number of puffs during smoking. However, a lower ventilation level across the filter reduces the likelihood that the smoking article will free air self-extinguishing during smoking. Accordingly, the ventilation level may be selected according to these properties of the smoking article.

In some examples, the paper wrapper surrounding the tobacco rod has a basis weight of ^{24-36 g/m 2 .} The weight of the paper is one of the factors that can affect the diffusivity of the paper. The increased weight per square meter of paper increases the diffusivity of the paper. Therefore, in order to provide a low diffusivity for the wrapper, the weight of the paper is chosen to be ^{between 24 and 36 g/m 2 .} In some examples, the paper surrounding the tobacco rod has a weight of ^{27 to 32 g/m 2 .} In some examples, the paper surrounding the tobacco rod has a weight of ^{about 28 g/m 2 .} In some examples, the paper surrounding the tobacco rod has a weight of ^{about 32 g/m 2 .} The higher weight per square meter of the paper wrapper 3 may also provide increased opacity of the paper wrapper. Increasing the basis weight of the paper together with increasing the diffusivity of the paper reduces the level of contamination of the cigarette paper during smoking.

In some examples, the paper may include a filler. In some examples, the filler content of the paper wrapper 3 is less than 30% by weight of the paper. In some examples, the filler content of the paper wrapper is between 15 and 25% by weight. A lower filler content reduces the diffusion capacity of the paper wrapper and thus can also lead to increased low ignition propensity (LIP) pass rates. Also, using a lower filler content may increase the number of puffs achievable when the smoking article is smoked during use. The filler content of the paper wrapper may exceed 15%. In some examples, the filler content of the paper wrapper may be between 21 and 22 weight percent. In some examples, the filler is calcium carbonate. However, it will be appreciated that any other suitable filler may be used. It will be appreciated that the amount of filler used may be selected by one of ordinary skill in the art to achieve desired properties such as, but not limited to, diffusivity, number of puffs, opacity, smoke yield, and LIP passage rate.

The opacity of the paper can be affected by the particle size of the filler used. For example, smaller particle sizes may result in higher opacity. In some examples, the particle size can be between 0.3 μm and 2 μm. Opacity can also be affected by the structure of the filler. For example, when calcium carbonate is used as a filler, it may include, but is not limited to, calcite crystals, precipitated calcium carbonate, or ground calcium carbonate.

In some examples, the paper wrapper includes a combustion additive. In some examples, the paper wrapper includes less than 4% by weight combustion additive. The combustion additive reduces the likelihood that the smoking article will free air self-extinguishing, for example when the user is holding the smoking article between puffs. However, increasing the level of the combustion additive may decrease the LIP passage rate of the smoking article. In some examples, the paper wrapper includes 1 wt % combustion additive. In some examples, the combustion additive is tri-potassium citrate. In some examples, the combustion additive is tri-sodium citrate. In some examples, the combustion additive includes tri-sodium citrate and tri-potassium citrate. However, it will be appreciated that any suitable combustion additive may be used. The amount of combustion additive can be selected by one of ordinary skill in the art to achieve desired properties, such as, but not limited to, smoke yield, and LIP pass rate.

In some examples, the filter comprises a filter material having a denier per filament of from about 2.5 to about 9, such as from about 3 to about 8.

In some examples, the filter comprises a filter material having a total denier of from about 10,000 to about 32,000, such as from about 12,000 to about 30,000.

2 illustrates a smoking article 1 ′ according to a further embodiment, except that the smoking article 1 ′ has a filter 4 comprising a capsule 8 , the smoking article 1 of FIG. 1 . same as In this example, the filter 4 is formed of a filter material, in this case cellulose acetate tow treated with a plasticizer, in this case triacetin. The capsule 8 is spherical and has a diameter of 3.5 mm, although other shapes and sizes of the capsule may be used, such as a capsule having a diameter of about 3 mm, or 0.5 mm to 6 mm, or 2 mm to 5 mm. . The capsule 8 is embedded on all sides by the filter material of the filter 4 and is surrounded by it. The capsule 8 contains a fluid additive that modifies the properties of the mainstream smoke passing through the smoking article 11 . The capsule 8 may be manufactured and inserted into the filter 4 using existing processes and machinery. In this example, the capsule 8 contains the menthol flavoring agent, but other fluids or granular additives may be retained within the capsule 8 . The capsule may be ruptured by the consumer squeezing the filter to release the fluid additive into the filter material of the filter 4 . The filter 4 of FIG. 2 may have a length of 7 mm to 30 mm, for example, 7 mm to 20 mm. In one example, the filter 4 is 18 mm long.

3 illustrates a smoking article 1 ″ according to a further embodiment, wherein the smoking article 1 ″ has a filter section 4a similar to the filter 4 of FIG. 1 coaxially connected to a tubular element 4b. It is the same as the smoking article 1 of FIG. 1 except that it has The tubular element 4b is formed of a fibrous filter material in this example. The fibrous filter material, in this example, is a continuous cellulose acetate tow plasticized with triacetin. The channel extends longitudinally through the center of the tubular element 4b. The channel extending through the center of the filter element 4b may have a diameter of 1 mm to 6 mm, for example 2 mm to 5 mm in diameter. The tubular element 4b may be an unwrapped element or may be wrapped with a plug wrap (not shown). The filter section 4a may also be wrapped or unwrapped with a plug wrap (not shown), and the mating plug wrap 10 may be used to connect the tubular element 4b and the filter section 4a. The filter section 4a may be between 6 mm and 30 mm in length, for example between 6 mm and 20 mm. In one example, the filter section 4a is 12 mm or 18 mm in length. The hollow tubular element 4b may be between 6 mm and 15 mm in length, for example between 6 mm and 12 mm in length or in one example 7 mm.

4 illustrates a smoking article 1 ″″ according to a further embodiment, wherein the smoking article 1 ″″ is a filter comprising an adsorbent material 9 dispersed in the filter material upstream of the filter section 4a. Same as smoking article 1 ″ of FIG. 3 except with segment 4c. The mating plug wrap 10 may be used to connect the tubular element 4b, the filter section 4a, and the filter segment 4c. The adsorbent material 9, in this example, is provided in the form of activated carbon particles, but other types of adsorbent such as ion exchange resins may be used. The filter section 4c can be between 6 mm and 20 mm in length, for example between 6 mm and 18 mm in length or in one example 12 mm.

In a method of making a smoking article, such as a smoking article as described herein, in a first step, tobacco material is placed in a paper wrapper having a diffusivity of between about 0.1 cm/s and 0.5 cm/s and a permeability of less than about 15 CU. By wrapping the tobacco rod is formed. In a second step, the filter may be attached to the tobacco rod. In a third step, a ventilation region may be provided to enable ventilation into the filter.

In some examples of the method, the paper wrapper has a diffusivity of about 0.1 cm/s to about 0.3 cm/s. In some examples, the paper wrapper has a permeability of about 4 to about 12 CUs over at least 50% of the surface area of the wrapper. In some examples, the paper wrapper has a permeability of from about 4 to about 12 CUs over at least 90% of the surface area of the wrapper.

Examples of smoking articles according to embodiments are described below. Unless otherwise specified, testing of smoking articles was performed according to ISO 3308: 2000, in which 35 ml puffs of a duration of 2 seconds are taken every 60 seconds.

Example 1

An exemplary cigarette was produced having a filter arrangement as illustrated in FIG. 4 and a circumference of about 23.4 mm. The net weight of cigarettes in the tobacco rod was 560 mg/cigaret. The paper wrapper basis weight was 28 g/m ² . The burn additive level was 1%. The total filter length was 34 mm and was connected to a tobacco rod having a length of 56 mm to give a total cigarette length of 90 mm. Tip ventilation was arranged to be about 68%. The pressure drop across the filter was about 100 mmWG. The number of puffs achieved using these parameters was about 9.5, delivering about 5 mg of tar.

Example 2

An exemplary cigarette was produced having a filter arrangement as illustrated in FIG. 4 and a circumference of about 23.4 mm. The net weight of cigarettes in the tobacco rod was 630 mg/cigaret. The paper wrapper basis weight was 28 g/m ² . The burn additive level was 1%. The total filter length was 27 mm and was connected to a tobacco rod having a length of 63 mm to give a total cigarette length of 90 mm. Tip ventilation was arranged to be about 67%. The pressure drop across the filter was about 90 mmWG. The number of puffs achieved using these parameters was about 11 delivering about 7 mg of tar.

Example 3

An exemplary cigarette was produced having a filter arrangement as illustrated in FIG. 4 and a circumference of about 21 mm. The paper wrapper basis weight was 28 g/m ² . The burn additive level was 1%. The total filter length was 27 mm and was connected to a tobacco rod having a length of 63 mm to give a total cigarette length of 90 mm. Tip ventilation was arranged to be about 72%. The pressure drop across the filter was about 177 mmWG. The number of puffs achieved using these parameters was about 10.3 delivering about 6.1 mg of tar.

The various embodiments described herein are presented merely to teach and to aid in understanding the claimed features. These examples are provided only as representative samples of the examples, and are not intended to be limiting and/or exclusive. Advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are limitations to the scope of the invention as defined by the claims, or to their equivalents. It is not to be considered as limitations, and it is to be understood that other embodiments may be utilized and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the present invention may suitably include, or may include, suitable combinations of other disclosed elements, components, features, parts, steps, means, etc. than those specifically described herein. may consist of, or consist essentially of. In addition, this disclosure may cover other inventions not currently claimed but may be claimed in the future.

Claims (30)

A smoking article comprising:
a tobacco material wrapped in a paper wrapper to form a tobacco rod;
wherein the paper wrapper has a diffusivity of about 0.1 cm/s to 0.5 cm/s and a permeability of less than about 15 CU. According to claim 1,
wherein the paper wrapper has a diffusivity of about 0.1 cm/s to 0.3 cm/s. 3. The method according to claim 1 or 2,
wherein the paper wrapper has a diffusivity of from about 0.15 to about 0.25, from about 0.15 to about 0.20, or from about 0.17 to about 0.22 cm/s. 4. The method according to any one of claims 1 to 3,
wherein the paper wrapper has a permeability of less than about 15 CU over at least 50% of the surface area of the paper wrapper. 5. The method of claim 4,
wherein the paper wrapper has a permeability of from about 4 to about 12 CUs. 5. The method of claim 4,
wherein the paper wrapper has a permeability of from about 4 to about 12 CUs over at least 90% of the surface area of the paper wrapper. 5. The method according to any one of claims 1 to 4,
wherein the paper wrapper has a permeability over at least 90% of the surface area of the paper wrapper, less than about 10 CUs, or from about 3 to about 7 CUs. 8. The method according to any one of claims 1 to 7,
A smoking article, further comprising a filter. 9. The method of claim 8,
wherein the pressure drop across the filter is between about 40 mm WG and 180 mm WG. 10. The method according to claim 8 or 9,
wherein the filter comprises a ventilation area. 11. The method of claim 10,
wherein the ventilation zone provides ventilation between 40% and 90%. 12. The method according to any one of claims 8 to 11,
wherein the filter comprises a filter material having a denier per filament of between 2.5 and 9. 13. The method according to any one of claims 8 to 12,
wherein the filter comprises a filter material having a total denier of 10,000 to 32,000. 14. The method according to any one of claims 1 to 13,
wherein the paper wrapper has a basis weight of ^{24-36 g/m 2 .} 15. The method of claim 14,
wherein the paper wrapper has a basis weight of 27 to 32 g/m ^{2 .} 16. The method of claim 15,
wherein the paper wrapper has a basis weight of ^{about 28 g/m 2 .} 16. The method of claim 15,
wherein the paper wrapper has a basis weight of ^{about 32 g/m 2 .} 18. The method according to any one of claims 1 to 17,
wherein the paper wrapper comprises less than 30% filler by weight of the paper wrapper. 19. The method of claim 18,
wherein the paper wrapper comprises 15% to 25% by weight filler. 20. The method of claim 18 or 19,
wherein the filler comprises calcium carbonate. 21. The method according to any one of claims 1 to 20,
wherein the paper wrapper has an opacity of 60% to 80%, or 68% to 80%. 22. The method according to any one of claims 1 to 21,
wherein said paper wrapper comprises less than 4 weight percent combustion additive of said paper wrapper. 23. The method of claim 22,
wherein the paper wrapper comprises about 1% by weight of a combustion additive. 24. The method of claim 22 or 23,
wherein the combustion additive is sodium citrate, potassium citrate, or a mixture of sodium and potassium citrate. A method of making a smoking article, comprising:
A method of making a smoking article, comprising: forming a tobacco rod by wrapping the tobacco material in a paper wrapper having a diffusivity of about 0.1 cm/s to 0.5 cm/s and a permeability of less than about 15 CU. 26. The method of claim 25,
and a filter for the tobacco rod. 27. The method of claim 26,
and providing a ventilation zone for facilitating ventilation into the filter. 28. The method according to any one of claims 25 to 27,
wherein the paper wrapper has a diffusivity of about 0.1 cm/s to 0.3 cm/s. 29. The method according to any one of claims 25 to 28,
wherein the paper wrapper has a permeability of from about 4 to about 12 CUs over at least 50% of the surface area of the wrapper. 30. The method according to any one of claims 25 to 29,
wherein the paper wrapper has a permeability of from about 4 to about 12 CUs over at least 90% of the surface area of the wrapper.

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