JP2023505423A - Aerosol-generating article comprising hollow tubing segments containing polyhydroxyalkanoic acid - Google Patents

Abstract

An aerosol-generating article (10, 100, 310) is provided for generating an inhalable aerosol upon heating, the aerosol-generating article comprising a rod of aerosol-generating substrate (12, 114, 312) and a fibrous a hollow tube segment (14, 120, 320) comprising a filter material of and disposed in longitudinal alignment with the rod (12, 114, 312) downstream of the rod (12, 114, 312); and the fibrous filtration material comprises fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer. [Selection drawing] Fig. 3

Description

The present invention relates to hollow tube segments for use in aerosol-generating articles and aerosol-generating articles comprising hollow tube segments. The invention further relates to aerosol-generating devices and aerosol-generating systems comprising such aerosol-generating articles.

Conventional aerosol-generating articles, such as filter cigarettes, typically consist of a cylindrical rod of tobacco cut filler surrounded by a paper wrapper, in almost end-to-end abutting relationship with the rolled tobacco rod. and an axially aligned cylindrical filter. Cylindrical filters typically comprise one or more plugs of fibrous filter material, such as cellulose acetate tow, surrounded by paper plug wrap. Conventionally, the rolled tobacco rod and filter are joined by a strip of tipping wrapper, usually formed from an opaque paper material, that surrounds the entire length of the filter and adjacent portions of the rolled tobacco rod.

Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted are also well known in the art. Typically, in such articles the aerosol is generated by heat transfer from a heat source to a physically separate aerosol-generating substrate or material.

By way of example, aerosol-generating articles have been proposed in which the aerosol is generated by electrical heating of the aerosol-generating substrate. Numerous prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generating devices in which the aerosol is generated by heat transfer from one or more electrical heater elements of the aerosol generating device to the aerosol generating substrate of the heated aerosol generating article. As another example, aerosol-generating articles are also known in which the aerosol is generated by the transfer of heat from a combustible fuel element or heat source to the aerosol-generating substrate. The combustible fuel element or heat source may be in contact with the aerosol-generating substrate, located within, around the aerosol-generating substrate, or downstream of the aerosol-generating substrate.

During use of such aerosol-generating articles, volatile compounds are released from the aerosol-generating substrate by heat transfer and are entrained in the air drawn through the aerosol-generating article. As the released compound cools, it condenses to form an aerosol.

Typically, aerosol-generating articles of the type described may include a mouthpiece with filter segments formed of a porous filtration material such as cellulose acetate. In some known aerosol-generating articles, a hollow tubular segment formed of a filtering material such as cellulose acetate is provided at a location between the aerosol-generating substrate and the mouth end of the article to provide structural strength to the article. Give.

Some aerosol-generating articles have also been described that include hollow tube segments formed of fibrous filtration material. By way of example, an aerosol-generating article is disclosed that includes a rod of aerosol-generating substrate as well as a support element in the form of a hollow acetate tube. In one particular embodiment, such an aerosol-generating article comprises, in a linear continuous arrangement, a rod of aerosol-generating substrate, a hollow acetate tube located immediately downstream of the aerosol-forming substrate, and a hollow acetate tube. It comprises a downstream aerosol cooling element and an outer wrapper surrounding the rod, hollow acetate tube and aerosol cooling element.

Further, the filter comprises a hollow tube segment formed of fibrous filtration material, preferably the hollow tube segment is combined with another solid segment formed of fibrous filtration material so that the axial Conventional aerosol-generating articles have been proposed that are aligned with the . As an example, a filter cigarette in which a hollow tube segment is disposed at the mouth end of the filter cigarette such that a cavity internally defined by such hollow tube segment opens to the outside environment. disclosed. Filter cigarettes are also disclosed in which such hollow tube segments are disposed between solid segments formed of fibrous filtering material. A cavity internally defined by a hollow tube segment and bounded at its ends by two solid segments may contain an aerosol altering substance such as an absorbent material or a breakable flavor capsule.

After the aerosol-generating article is consumed and discarded, it is desirable that any component of the article, including the filtering material, degrade as quickly as possible. However, cellulose acetate and many other commonly used filter materials are not highly biodegradable. However, alternative dispersible or biodegradable materials often fail to provide acceptable filtration efficiencies and smoking experiences for consumers. In addition, many known dispersible and degradable materials are not suitable for use in existing manufacturing processes, and existing methods and equipment require excessive amounts of effort to make their use commercially viable. correction will be required.

Additionally, cellulose acetate has been found to provide relatively high levels of adsorption and entrapment of water from mainstream smoke when used in conventional smoking articles. Thus, mainstream smoke delivered to consumers has a significantly reduced moisture content and can be perceived as undesirably "dry" under certain conditions. This can adversely affect the overall smoking experience.

Thus, it would be desirable to provide new and improved aerosol-generating articles that have enhanced biodegradation properties compared to known articles comprising conventional filtration materials such as cellulose acetate. New and improved aerosols that also provide an acceptable smoking experience to the consumer, especially with the ability to reduce the effects of "dry" smoke often found in articles containing cellulose acetate as a filtering material. It would be desirable to provide a generating article.

It would be desirable to provide an aerosol-generating article such that the withdrawal resistance (RTD) of the filtration material segments can be adjusted to achieve an acceptable RTD for the article as a whole. Additionally, it would be desirable to provide such aerosol-generating articles that can be efficiently manufactured in automated and rapid manufacturing processes without requiring major modifications to existing equipment.

The present disclosure relates to aerosol-generating articles for producing an inhalable aerosol upon heating. The aerosol-generating article may comprise a rod of aerosol-generating substrate and a hollow tube segment comprising a fibrous filtering material. The hollow tube segments may be disposed in longitudinal alignment with the rod. Fibrous filtration materials may include fibers comprising polyhydroxyalkanoic acid (PHA) polymer or copolymer materials.

Additionally, the present disclosure relates to hollow tube segments for use in aerosol-generating articles. The hollow tube segments may be formed of fibrous filtration material. Fibrous filtration materials may include fibers comprising polyhydroxyalkanoic acid (PHA) polymer or copolymer materials.

Additionally, the present disclosure relates to a system comprising an aerosol-generating device and an aerosol-generating article for use with the aerosol-generating device. The aerosol-generating article may comprise a rod of aerosol-generating substrate and a hollow tube segment comprising a fibrous filtering material. In the aerosol-generating device, the hollow tube segment may be arranged in longitudinal alignment with the rod. The fibrous filtration material may comprise fibers comprising polyhydroxyalkanoic acid (PHA) polymers or copolymers.

According to the present invention there is provided an aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising a rod of aerosol-generating substrate and a fibrous filtering material, and and longitudinally aligned hollow tube segments, the fibrous filtration material includes fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer.

The term "aerosol-generating article" is used herein with respect to the present invention to describe an article in which an aerosol-generating substrate is heated to produce an aerosol for delivery to a consumer. As used herein, the term "aerosol-generating substrate" means a substrate capable of releasing a volatile compound upon heating to generate an aerosol.

A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette ignites the ends of the cigarette and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol-generating articles, the aerosol is generated by heating a flavor-generating substrate, such as, for example, a tobacco-derived substrate or a substrate containing an aerosol former and a flavorant. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which aerosol is generated by heat transfer from a combustible fuel element or heat source to a physically separate aerosol-forming material. included.

As used herein, the term "longitudinal" refers to the direction corresponding to the major longitudinal axis of the aerosol-generating article, extending between the upstream and downstream ends of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" describe the relative positions of elements (or portions of elements) of an aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use. do.

As briefly mentioned above, in contrast to existing aerosol-generating articles, the article according to the present invention comprises a hollow tube segment comprising a fibrous filtration material, the fibrous filtration material comprising a polyhydroxyalkanoic acid ( PHA) including fibers containing polymers or copolymers.

Thus, in hollow tube segments of aerosol-generating articles according to the invention, the PHA polymer or copolymer comprises at least a portion of the fibrous filtration material. This means that the remaining portion of the fibrous filtration material may contain materials other than PHA polymers or copolymers. In addition, it can be, for example, a plug wrapper surrounding a fibrous filtration material, or a non-cuttable object such as an insert, a flow restrictor, or an additive delivery material such as a frangible capsule along the hollow tube segment. It is meant that other components of the hollow tube segment that may be provided in place may comprise materials other than PHA polymers or copolymers.

Fibers containing PHA polymers or copolymers (hereinafter also referred to as PHA fibers) are hydrophilic compared to fibers of other filtration materials, such as cellulose acetate, of comparable weight in aerosol-generating articles according to the present invention. As such, hollow tube segments have been found to have a significantly lower tendency to absorb water/steam. As a result, in those embodiments, water levels in mainstream smoke are advantageously maintained at higher levels when hollow tube segments are used as components of multi-segment filters in conventional smoking articles. obtain. This directly addresses the "dry smoke" problem often encountered in conventional smoking articles and provides the consumer with an improved smoking experience.

Since PHA fibers have a much higher level of biodegradability compared to fibers of other filtration materials such as cellulose acetate, articles according to the invention are generally more biodegradable. At the same time, since PHA fibers are obtained by natural fermentation processes, the aerosol-generating articles according to the invention also provide sustainability improvements to the manufacturing process. Moreover, hollow tube segments have a larger exposed surface area compared to cylindrical plugs, which may also be more advantageous for biodegradation.

By adjusting parameters such as denier per filament, total denier, cross-sectional shape, etc., it is possible to adjust the RTD of the filter segments to the desired range for any given filter length or filter design.

The term "denier per filament" (dpf) corresponds to the weight in grams of a single fiber or filament having a length of 9000 meters. Therefore, in the present invention, the dpf value provides an indication of the thickness of each individual PHA fiber within the filter segment. Denier per filament is expressed in units of denier, where 1 denier corresponds to 1 gram per 9000 meters.

The "total denier" of a filtration material defines the total weight in grams of 9000 meters of combined fibers forming the filtration material. Thus, the total denier of a filter segment corresponds to the denier per filament multiplied by the total number of fibers in the filter segment.

Additionally, the overall weight of the hollow tube segment can be advantageously controlled, which can also contribute to biodegradation of the hollow tube segment and the aerosol-generating article as a whole.

PHA properties also lead to good filter hardness, which can be further enhanced by surrounding the hollow tube segments with hard plugwrap.

An aerosol-generating article according to the present invention comprises a rod of aerosol-generating substrate.

A rod of aerosol-generating substrate may be produced using randomly oriented pieces, strands, or strips of tobacco material. Alternatively, the rod of aerosol-generating substrate may be formed from an assembly of one or more sheets of tobacco material, for example as proposed in WO-A-2012/164009. An alternative to aerosol-generating articles formed from strands of homogenized tobacco material, which may be formed by casting, rolling, calendering, or extruding a mixture comprising tobacco particulate and at least one aerosol former. rods have also been proposed. Further, the rod of aerosol-generating substrate is a homogenized tobacco material obtained by extruding a mixture comprising particulate tobacco and at least one aerosol former to form a continuous length of homogenized tobacco material. It may be formed from strands of tobacco material.

The rods of the aerosol-generating substrate preferably have an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

The aerosol-generating substrate rod preferably has an outer diameter of at least 5 millimeters. The rod of aerosol-generating substrate may have an outer diameter of about 5 millimeters to about 12 millimeters, such as an outer diameter of about 5 millimeters to about 10 millimeters, or an outer diameter of about 6 millimeters to about 8 millimeters. In one preferred embodiment, the rod of aerosol-generating substrate has an outer diameter within 7.2 millimeters ±10 percent.

A rod of aerosol-generating substrate may have a length of about 5 millimeters to about 100 mm. The rods of aerosol-generating substrate preferably have a length of at least about 5 millimeters, and more preferably have a length of at least about 7 millimeters. Additionally or alternatively, the rods of aerosol-generating substrate preferably have a length of less than about 80 millimeters, more preferably less than about 65 millimeters, and less than about 50 millimeters. is even more preferred. In particularly preferred embodiments, the rods of aerosol-generating substrate have a length of less than about 35 millimeters, more preferably less than 25 millimeters, and even more preferably less than about 20 millimeters. preferable. In one embodiment, the rod of aerosol-generating substrate may have a length of about 10 millimeters. In one preferred embodiment, the rod of aerosol-generating substrate has a length of about 12 millimeters.

The rod of aerosol-generating substrate preferably has a substantially uniform cross-section along the length of the rod. It is particularly preferred that the rods of the aerosol-generating substrate have a substantially circular cross-section.

In preferred embodiments, the aerosol-generating substrate comprises a collection of one or more homogenized sheets of tobacco material. The one or more sheets of homogenized tobacco material are preferably textured. As used herein, the term "textured sheet" means a sheet that has been crimped, embossed, debossed, perforated, or otherwise deformed. Textured sheets of homogenized tobacco material for use in the present invention may include a plurality of spaced apart indentations, protrusions, perforations, or a combination thereof. According to a particularly preferred embodiment of the present invention, the rod of aerosol-generating substrate comprises an assembly of crimped sheets of homogenized tobacco material surrounded by a wrapper.

As used herein, the term "crimped sheet" is intended to be synonymous with the term "crinkled sheet" and means a sheet having a plurality of substantially parallel ridges or corrugations. do. The crimped sheet of homogenized tobacco material preferably has a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the rod according to the invention. This advantageously facilitates assembly of crimped sheets of homogenized tobacco material to form rods. However, it should be appreciated that the crimped sheet of homogenized tobacco material used in the present invention may alternatively or additionally comprise a plurality of barbs arranged at an acute or obtuse angle to the cylindrical axis of the rod. ridges or corrugations that are parallel to each other. In certain embodiments, the sheet of homogenized tobacco material used in the rods of the articles of the present invention may be textured substantially evenly over substantially its entire surface. For example, a crimped sheet of homogenized tobacco material for use in making rods for use in aerosol-generating articles according to the present invention may have a plurality of substantially parallel ridges or corrugations spaced substantially uniformly across the width of the sheet. may include

The sheets or webs of homogenized tobacco material used in the present invention may have a tobacco content of at least about 40 weight percent on a dry weight basis and have a tobacco content of at least about 60 weight percent on a dry weight basis. More preferably, it has a tobacco content of at least about 70 weight percent on a dry weight basis, and most preferably has a tobacco content of at least about 90 weight percent on a dry weight basis.

Sheets or webs of homogenized tobacco material for use in aerosol-generating substrates may be coated with one or more intrinsic binders (i.e., tobacco intrinsic binders) to help agglomerate the particulate tobacco. The above exogenous binders (ie, tobacco exogenous binders), or combinations thereof. Alternatively or additionally, the sheet of homogenized tobacco material for use in the aerosol-generating substrate may include tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and Other additives may be included, including but not limited to non-aqueous solvents, as well as combinations thereof.

Suitable extrinsic binders for inclusion in sheets or webs of homogenized tobacco material for use in aerosol-generating substrates are well known in the art and include gums such as guar gum, xanthan gum, gum arabic, and locust bean gum, cellulosic binders, and the like. binders (such as hydroxypropylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, and ethylcellulose), polysaccharides (such as starch, organic acids (such as alginic acid), conjugate base salts of organic acids (such as sodium alginate), agar, pectin, etc. ), and combinations thereof.

Suitable non-tobacco fibers for inclusion in sheets or webs of homogenized tobacco material for use in aerosol-generating substrates are known in the art and include cellulose fibers, softwood fibers, hardwood fibers, jute fibers, and combinations thereof. but not limited to these. Prior to inclusion in sheets of homogenized tobacco material for use in aerosol-generating substrates, the non-tobacco fibers may be treated by any suitable process known in the art, including mechanical pulping, refining, chemical pulping. , bleaching, sulfate pulping, and combinations thereof.

Substrates for heated aerosol-generating articles are typically "aerosol formers," i.e., that facilitate the formation of aerosols during use, and are preferably substantially resistant to thermal decomposition at the temperature of use of the aerosol-generating article. Including compounds or mixtures of compounds. Examples of suitable aerosol formers include polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, esters of polyhydric alcohols such as glycerol monoacetate, diacetate or triacetate, and Aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.) can be mentioned. Preferred aerosol formers are polyhydric alcohols or mixtures thereof such as propylene glycol, triethylene glycol, 1,3-butanediol, most preferably glycerin.

The aerosol-generating substrate preferably comprises at least about 10 weight percent aerosol former, more preferably at least about 12 weight percent aerosol former, more preferably at least about 15 weight percent aerosol former. Alternatively or additionally, the aerosol-generating substrate preferably comprises no more than 30 weight percent aerosol formers, more preferably no more than about 25 weight percent aerosol formers, more preferably no more than about 20 weight percent aerosol formers. including. For example, the aerosol-generating substrate comprises from about 10 weight percent to about 30 weight percent aerosol formers, or from about 12 weight percent to about 25 weight percent aerosol formers, or from about 15 weight percent to about 20 weight percent aerosol formers. may include In a particularly preferred embodiment, the aerosol-generating substrate comprises approximately 18 weight percent aerosol formers.

In aerosol-generating articles according to the invention, the filter segment is formed of a fibrous filtration material comprising fibers comprising polyhydroxyalkanoic acid (PHA) polymers or copolymers. The fibrous filtration material preferably comprises at least about 85 weight percent fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer.

PHAs are a family of polyhydroxyesters of 3-, 4-, 5-, and 6-hydroxyalkanoic acids, which are produced by various bacterial species under nutrient-limiting conditions in the presence of excess carbon and stored in bacterial cells. are found as individual cytoplasmic inclusion bodies. Due to their excellent biocompatibility, PHAs have been proposed for use in a wide range of biomedical applications, including drug delivery systems and tissue engineering scaffolds.

PHA molecules typically consist of 600-35,000 (R)-hydroxy fatty acid monomer units. Depending on the total number of carbon atoms in the PHA monomer, PHA can be classified as short chain length PHA (scl-PHA; 3-5 carbon atoms), medium chain length PHA (mcl-PHA; 6-14 carbon atoms ), or long chain length PHA (lcl-PHA; 15 or more carbon atoms).

The first and most widely recognized PHA is poly(β-hydroxybutyric acid) (PHB). The next member of the PHA family is poly(3-hydroxyvaleric acid) or PHV, which has pendant ethyl groups. Having an ethyl group (HV units) instead of the methyl group of PHB gives PHV greater flexibility and lower crystallinity than PHB.

In aerosol-generating articles according to the present invention, the hollow tube segments preferably comprise at least about 25 weight percent PHA polymer or copolymer. More preferably, the hollow tube segment comprises at least about 50 weight percent PHA polymer or copolymer. Even more preferably, the hollow tube segment comprises at least about 60 weight percent PHA polymer or copolymer. In particularly preferred embodiments, the hollow tube segment comprises at least about 70 weight percent PHA polymer or copolymer, or at least about 80 weight percent PHA polymer or copolymer. In some highly preferred embodiments, the hollow tube segment comprises at least about 85 weight percent PHA polymer or copolymer. More preferably, the PHA polymer or copolymer is one or more of polyhydroxypropionic acid, polyhydroxyvaleric acid, polyhydroxybutyric acid, polyhydroxyhexanoic acid, and polyhydroxyoctanoic acid. In a particularly preferred embodiment, the PHA compound is poly(3-hydroxybutyric acid).

Even more preferably, the hollow tube segment comprises at least about 90 weight percent PHA polymer or copolymer. While not wishing to be bound by theory, it is believed that higher PHA content in hollow tube segments is generally associated with improved biodegradability of the hollow tube segment and the aerosol-generating article as a whole. understood.

The fibrous filtration material is at least about 91 weight percent PHA polymer or copolymer, or at least about 92 weight percent PHA polymer or copolymer, or at least about 93 weight percent PHA polymer or copolymer, or More preferably, it contains at least about 94 weight percent PHA polymer or copolymer. In some particularly preferred embodiments, the fibrous filtration material comprises at least about 95 weight percent PHA polymer or copolymer.

The remainder of the fibers within the PHA filter segment may comprise any suitable material. Suitable fibrous materials are well known to those skilled in the art and include, but are not limited to, polylactic acid (PLA) and cellulose acetate.

In some examples, the fibrous filter material of the hollow tube segment may include some cellulose acetate. Without wishing to be bound by theory, it is believed that a certain amount of cellulose acetate in the hollow tube segment may not only facilitate the manufacture of the hollow tube segment, but also provide the desired filtration properties and mechanical properties for the hollow tube segment. It is understood that the

In certain embodiments, the fibrous filtration material of the hollow tube segment comprises at least about 5 weight percent cellulose acetate. As an example, the fibrous filtration material comprises at least about 6 weight percent cellulose acetate, or at least about 7 weight percent cellulose acetate, or at least about 8 weight percent cellulose acetate, or at least about 9 weight percent cellulose acetate. It's okay. In some embodiments, the fibrous filtration material comprises at least about 10 weight percent cellulose acetate.

In aerosol-generating articles according to the present invention, the fibrous filtration material preferably comprises less than about 15 weight percent cellulose acetate.

In some embodiments, the fibrous filtration material of the hollow tube segment is less than about 5 weight percent cellulose acetate, preferably less than 3 weight percent cellulose acetate, more preferably less than 1 weight percent cellulose acetate; Even more preferably it contains less than 0.1 weight percent cellulose acetate. This can further advantageously contribute to enhanced biodegradability of the hollow tube segment and the entire aerosol-generating article.

Aerosol-generating articles according to the present invention preferably contain no more than about 10 weight percent cellulose acetate measured with respect to the total weight of the aerosol-generating article. More preferably, aerosol-generating articles according to the present invention comprise no more than about 7 weight percent cellulose acetate measured with respect to the total weight of the aerosol-generating article. Even more preferably, aerosol-generating articles according to the present invention comprise no more than about 5 weight percent cellulose acetate measured with respect to the total weight of the aerosol-generating article. This is advantageous not only because the hollow tube segments have low or no cellulose acetate content, but also because any other component of the article containing the fibrous filtration material contains little or no cellulose acetate. Indicates that it does not contain at all. Embodiments of aerosol-generating articles according to the present invention having such low cellulose acetate content exhibit particularly favorable biodegradability properties.

In some preferred embodiments, aerosol-generating articles according to the present invention comprise no more than about 3 weight percent cellulose acetate measured with respect to the total weight of the aerosol-generating article. More preferably, aerosol-generating articles according to the present invention contain no more than about 2 weight percent cellulose acetate measured with respect to the total weight of the aerosol-generating article. Even more preferably, aerosol-generating articles according to the present invention comprise no more than about 1 weight percent cellulose acetate measured with respect to the total weight of the aerosol-generating article.

In some highly preferred embodiments, aerosol-generating articles according to the present invention are substantially free of cellulose acetate.

In some embodiments, the fibrous filter material is starch, polybutylene succinate (PBS), polybutyrate adipate terephthalate (PBAT), thermoplastic starch and thermoplastic starch blends (TPS), polycaprolactone (PCL) , polyglycolide (PGA), polyvinyl alcohol (PVOH/PVA), viscose, regenerated cellulose, polysaccharides, cellulose acetate with a degree of substitution (DS) less than 2.1, polyamides, protein-based biopolymers, chitosan-chitin system biopolymers, and at least one biodegradable polymer selected from the group consisting of combinations thereof.

The inventors have found that the inclusion of one or more of these components in the blend from which the fibrous material of the filter segment is formed further contributes to enhanced biodegradability of the filter segment and the aerosol-generating article as a whole. I discovered.

In addition, while it has previously been found to be technically difficult to produce PHA-containing filaments or fibers using existing techniques and equipment, the inventors have surprisingly found that PHA It has been found that when combined in a blend as described above, it is possible to produce filaments or fibers incorporating high levels of PHA as this makes it easier to form filaments by spinning techniques. .

In some embodiments, the fibrous filtration material comprises at least about 5 weight percent of such additional biodegradable polymers. In a preferred embodiment, the fibrous filtration material comprises at least about 10 weight percent of such additional biodegradable polymer. More preferably, the fibrous filtration material comprises at least about 11 weight percent, or at least 12 weight percent, or at least 13 weight percent, or at least 14 weight percent of the additional biodegradable polymer. Even more preferably, the fibrous filtration material comprises at least about 15 weight percent of such additional biodegradable polymers.

In particularly preferred embodiments, the at least one biodegradable polymer is one or more of PBAT, PCL and PBS. Without wishing to be bound by theory, the inventors believe that the use of one or more of these selected biodegradable polymers improves the mechanical properties, thermal properties, and We have found that it contributes to the improvement of morphological characteristics. In particular, the combined use of PBAT and PBS has been found to provide particularly balanced mechanical properties, particularly in terms of tensile strength and elongation.

In some embodiments, the fibrous filtration material comprises at least about 3 weight percent plasticizer selected from triacetin, triethylene glycol diacetate (TEGDA), ethylene vinyl acetate, polyvinyl alcohol, starch, or combinations thereof. include.

In some examples, the fibrous filtration material further includes a water-based adhesive. This has the effect of structurally reinforcing the structure of the hollow tube segment. By way of example, compounds such as starch glue, methylcellulose, or polyvinyl acetate may be used for this purpose.

The fibrous filtration material of the hollow tube segment preferably comprises a plurality of fibers comprising a PHA polymer or copolymer and having at least about 1 denier per filament. More preferably, the fibrous filtration material of the hollow tube segment comprises a PHA polymer or copolymer and comprises a plurality of fibers having at least about 2 denier per filament. Even more preferably, the fibrous filtration material of the hollow tube segment comprises a PHA polymer or copolymer and comprises a plurality of fibers having at least about 3.2 denier per filament.

In a preferred embodiment, the fibrous filtration material of the hollow tube segment comprises a PHA polymer or copolymer and comprises a plurality of fibers having about 10 denier per filament or less. More preferably, the fibrous filtration material of the hollow tube segment comprises a PHA polymer or copolymer and comprises a plurality of fibers having about 7.5 denier per filament or less. Even more preferably, the fibrous filtration material of the hollow tube segment comprises a PHA polymer or copolymer and comprises a plurality of fibers having about 5 denier per filament or less.

In some embodiments, the fibrous filtration material of the hollow tube segments comprises a PHA polymer or copolymer and has about 1 to about 10 or less, more preferably about 2 to about 10, even more preferably about 2 to about 10 per filament. includes a plurality of fibers having a denier from about 3.2 to about 10. In other embodiments, the fibrous filtration material of the hollow tube segments comprises a PHA polymer or copolymer and has about 1 to about 7.5 or less per filament, more preferably about 2 to about 7.5, Even more preferably, it comprises a plurality of fibers having a denier of from about 3.2 to about 7.5. In a further embodiment, the fibrous filtration material of the hollow tube segment comprises a PHA polymer or copolymer and has about 1 to about 5 or less per filament, more preferably about 2 to about 5, even more preferably about A plurality of fibers having a denier of 3.2 to about 5 is included.

While not wishing to be bound by theory, the inventors have found that when hollow tube segments are formed of PHA fibers with relatively low dpf of 1.5-3.2, the hollow tube segments It was found to exhibit a particularly low RTD, which may be desirable for certain aerosol-generating article designs. Such a low range of dpf also advantageously reduces the overall weight of the hollow tube segment, which further significantly improves the biodegradability of the aerosol-generating article.

The fibers comprising the PHA polymer or copolymer of the filter segment are preferably crimped.

The cross-sectional shape of the PHA fibers may vary, for example, to control the external surface area of the fibers within the hollow tube segment. By controlling the external surface area of the PHA fibers, the total surface area of the PHA fibers exposed to the aerosol as it passes through the hollow tube segment can also be controlled. This in turn provides some control over the filtration characteristics of the PHA fibers, for example the amount of water absorbed by the fibers of conventional combustible smoking articles.

In some embodiments, the PHA fibers have a substantially round cross-section. In such embodiments, the total external surface area of the PHA fibers within the hollow tube segments is preferably from about 0.15 square meters/gram to about 0.30 square meters/gram.

In an alternative embodiment, the PHA fibers have a Y-shaped cross-section. In such embodiments, the total external surface of the PHA fibers within the hollow tube segment is preferably from about 0.15 square meters/gram to about 0.55 square meters/gram. The total external surface of the PHA fibers within the hollow tube segment is more preferably from about 0.2 square meters/gram to about 0.5 square meters/gram, even more preferably from about 0.25 square meters/gram to about 0.45 square meters. /gram.

In some embodiments, the hollow tube segments may include one or more additives to reduce certain constituents in mainstream smoke. As an example, the filter segments preferably contain additives for the reduction of phenol and phenol derivatives. [. . . ]

The combination of PHA with additives such as PEG for the reduction of phenolic compounds from mainstream smoke has been found to be particularly effective. PHA fibers generally provide good filtration efficiency for undesirable smoke constituents, but are less effective at removing phenolic compounds. By incorporating compounds that specifically reduce the level of phenolic compounds in mainstream smoke, hollow tube segments, particularly as described above, can be used as components of multiple component filters of combustible smoking articles such as filter cigarettes. When used, it is possible to further optimize the filtering capacity of the hollow tube segment of the aerosol-generating article according to the invention. This in turn improves the sensory properties of the aerosol delivered to the consumer.

In particularly preferred embodiments, the hollow tube segment further comprises at least about 5 weight percent polyethylene glycol, based on the total weight of the filtration material. The hollow tube segments preferably contain no more than 10 weight percent polyethylene glycol, based on the total weight of the filtering material.

As noted above, PHA fibers have been found to absorb less water from mainstream smoke than equivalent amounts of cellulose acetate fibers due to the lower affinity of the PHA fibers for water. As shown in the examples below, the amount of water absorbed by a PHA filter segment is significantly lower than the amount of water absorbed by a comparative filter segment formed with a comparable weight of cellulose acetate fibers.

For example, when exposed to water in liquid form, the hollow tube segments of the aerosol-generating articles of the present invention exhibit an amount of water that would be absorbed under the same conditions by a comparable hollow tube segment formed from cellulose acetate fibers. It is preferred to absorb less than half.

The reduced absorption of water by the PHA fibers of the hollow tube segments of the present invention compared to cellulose acetate results in higher levels of water in the mainstream smoke delivered from the aerosol-generating article during use.

For example, the amount of water in mainstream smoke collected during smoking of a combustible smoking article comprising a filter according to the present invention using PHA fibers under ISO conditions is comparable to that of filter segments of cellulose acetate tow under the same conditions. at least 10 percent higher, preferably at least 15 percent higher than the amount of water in mainstream smoke collected during smoking of a comparable combustible smoking article having a

Thus, aerosol-generating articles with filters containing PHA hollow tube segments can deliver mainstream smoke with higher moisture levels, which is perceptually more pleasing to consumers. In particular, the effects of "dry smoke" that can be experienced during smoking of aerosol-generating articles using conventional cellulose acetate filters can be advantageously reduced.

Fibers containing PHA polymers or copolymers of filter segments may be manufactured by one of several techniques including melt spinning, gel spinning, and electrospinning. The fibers comprising the PHA polymer or copolymer of the filter segment of the aerosol-generating article according to the invention are preferably manufactured by melt spinning. Melt spinning is often regarded as the most economical spinning process because there is no need to recover or evaporate the solvent, as opposed to solution spinning. Furthermore, the spinning speeds with melt spinning are generally quite high, which is advantageous in terms of overall productivity and manufacturing efficiency.

In this process, a viscous melt of a polymer or polymer blend is extruded through a spinneret containing several holes into a chamber where a blast of cold air or gas is directed at the surface of filaments emanating from the spinneret. When air hits the filament, it solidifies and is collected on a take-up wheel or the like. The melt spinning process is advantageously characterized by a defined filament cross-sectional shape, giving a wide variety of finenesses and filament counts. By increasing the spinneret numerical aperture, high spinning capacities can be achieved, which are difficult to match with other spinning processes.

Preferably, in aerosol-generating articles according to the invention, the hollow tube segments do not substantially contribute to the overall RTD of the aerosol-generating article.

Thus, in aerosol-generating articles according to the present invention, a significant percentage of the overall volume of the hollow tube segments is substantially empty, so that the hollow tube segments contribute only a small amount to the overall RTD. As such, the overall RTD of the article preferably depends essentially on the RTD of the rod, and may further depend on the RTD of optional additional components such as mouthpieces or filter segments.

In practice, hollow tube segments can be adapted to generate RTDs ranging from approximately 0 millimeters H ₂ O (approximately 00 Pa) to approximately 20 millimeters H ₂ O (approximately 200 Pa). The hollow tube segment is preferably adapted to generate an RTD of approximately 0 millimeters H ₂ O (approximately 00 Pa) to approximately 10 millimeters H ₂ O (approximately 100 Pa).

Preferably, the aerosol-generating article has an overall RTD of less than about 90 millimeters _H2O (about 900 Pa). More preferably, the aerosol-generating article has an overall RTD of less than about 80 millimeters _H2O (about 800 Pa). Even more preferably, the aerosol-generating article has an overall RTD of less than about 70 millimeters _H2O (about 700 Pa).

The aerosol-generating article preferably has an overall RTD of at least about 30 millimeters _H2O (about 300 Pa). More preferably, the aerosol-generating article has an overall RTD of at least about 40 millimeters _H2O (about 400 Pa). Even more preferably, the aerosol-generating article has an overall RTD of at least about 50 millimeters _H2O (about 500 Pa).

In some embodiments, the aerosol-generating article is about 30 millimeters H ₂ O (about 300 Pa) to about 90 millimeters H ₂ O (about 900 Pa), preferably about 40 millimeters H ₂ O (about 400 Pa) to about 90 millimeters H 2 O (about 400 Pa). It has an overall RTD of H ₂ O (about 900 Pa), more preferably from about 50 millimeters H ₂ O (about 500 Pa) to about 90 millimeters H ₂ O (about 900 Pa). In other embodiments, the aerosol-generating article is about 30 millimeters H ₂ O (about 300 Pa) to about 80 millimeters H ₂ O (about 800 Pa), preferably about 40 millimeters H ₂ O (about 400 Pa) to about 80 millimeters H 2 O ₂ O (about 800 Pa), more preferably from about 50 millimeters H ₂ O (about 500 Pa) to about 80 millimeters H ₂ O (about 800 Pa). In further embodiments, the aerosol-generating article is about 30 millimeters H ₂ O (about 300 Pa) to about 70 millimeters H ₂ O (about 700 Pa), preferably about 40 millimeters H ₂ O (about 400 Pa) to about 70 millimeters H ₂ O (about 700 Pa), more preferably from about 50 millimeters H ₂ O (about 500 Pa) to about 70 millimeters H ₂ O (about 700 Pa).

The RTD of an aerosol-generating article is the shade that must be applied to the downstream end of the article to maintain a steady air volumetric flow rate of 17.5 ml/s through the article under test conditions as defined in ISO 3402. It may be evaluated as pressure. The RTD values listed above are for the aerosol-generating article by itself (i.e., without inserting the article into the aerosol-generating device) and for ventilation if the article is provided with a ventilation zone. It is intended to be measured without blocking any perforations in the zone.

In other embodiments, the aerosol-generating article is at least about 150 millimeters _H2O (about 1500 Pa), preferably at least about 200 millimeters _H2O (about 2000 Pa), more preferably at least about 250 millimeters _H2O (about 2500 Pa). ).

Hollow tube segments comprising PHA fibers according to the present invention have additionally been found to provide good stability for RTDs, meaning that high variability of RTDs can be advantageously avoided. . For example, within twenty samples of aerosol-generating articles according to the present invention, there will typically be a standard deviation from the target RTD of 2 percent to 10 percent, more preferably 2 percent to 5 percent.

The hollow tube segment preferably has a wall thickness of at least about 0.3 millimeters. More preferably, the hollow tube segment has a wall thickness of at least about 0.4 millimeters. Even more preferably, the hollow tube segment has a wall thickness of at least about 0.5 millimeters.

Preferably, the hollow tube segment has a wall thickness of about 1.9 millimeters or less. More preferably, the hollow tube segment has a wall thickness of about 1.5 millimeters or less. Even more preferably, the hollow tube segment has a wall thickness of about 1.2 millimeters or less. It is particularly preferred that the hollow tube segment has a wall thickness of about 0.9 millimeters or less.

In certain embodiments, the hollow tube segment is about 0.3 millimeters to about 1.9 millimeters, preferably about 0.4 millimeters to about 1.9 millimeters, more preferably about 0.5 millimeters to about 1.9 millimeters. It has a wall thickness of 9 millimeters. In some embodiments, the hollow tube segment is about 0.3 millimeters to about 1.5 millimeters, preferably about 0.4 millimeters to about 1.5 millimeters, more preferably about 0.5 millimeters to about 1 millimeter. It has a wall thickness of 0.5 millimeters. In other embodiments, the hollow tube segment is about 0.3 millimeters to about 1.2 millimeters, preferably about 0.4 millimeters to about 1.2 millimeters, more preferably about 0.5 millimeters to about 1.2 millimeters. It has a wall thickness of 2 millimeters. In further embodiments, the hollow tube segment is about 0.3 millimeters to about 0.9 millimeters, preferably about 0.4 millimeters to about 0.9 millimeters, more preferably about 0.5 millimeters to about 0.9 millimeters. It has a wall thickness of millimeters. In a particularly preferred exemplary embodiment, the hollow tube segment has a wall thickness of approximately 0.6 millimeters.

In some embodiments, hollow tube segments may typically have a length of at least about 4 millimeters. Preferably, the length of the hollow tube segment is at least about 5 millimeters. More preferably, the length of the hollow tube segment is at least about 7 millimeters. Even more preferably, the length of the hollow tube segment is at least about 10 millimeters.

In certain embodiments, the length of the hollow tube segment is about 35 millimeters or less. Preferably, the length of the hollow tube segment is about 25 millimeters or less. More preferably, the length of the hollow tube segment is about 20 millimeters or less. Even more preferably, the length of the hollow tube segment is about 15 millimeters or less.

In preferred embodiments, the length of the hollow tube segment is from about 4 millimeters to about 35 millimeters. Preferably, the length of the hollow tube segment is from about 5 millimeters to about 35 millimeters. More preferably, the length of the hollow tube segment is between about 7 millimeters and about 35 millimeters. Even more preferably, the length of the hollow tube segment is from about 10 millimeters to about 35 millimeters.

In certain other embodiments, the length of the hollow tube segment is from about 4 millimeters to about 25 millimeters. Preferably, the length of the hollow tube segment is from about 5 millimeters to about 25 millimeters. More preferably, the length of the hollow tube segment is between about 7 millimeters and about 25 millimeters. Even more preferably, the length of the hollow tube segment is between about 10 millimeters and about 25 millimeters.

In other embodiments, the length of the hollow tube segment is from about 4 millimeters to about 20 millimeters. Preferably, the length of the hollow tube segment is from about 5 millimeters to about 20 millimeters. More preferably, the length of the hollow tube segment is between about 7 millimeters and about 20 millimeters. Even more preferably, the length of the hollow tube segment is between about 10 millimeters and about 20 millimeters.

In further embodiments, the length of the hollow tube segment is from about 4 millimeters to about 15 millimeters. Preferably, the length of the hollow tube segment is between about 5 millimeters and about 15 millimeters. More preferably, the length of the hollow tube segment is between about 7 millimeters and about 15 millimeters. Even more preferably, the length of the hollow tube segment is between about 10 millimeters and about 15 millimeters.

In aerosol-generating articles according to the present invention, the hollow tube segments preferably have an average radial hardness of at least about 80 percent, more preferably at least about 85 percent, and even more preferably at least about 90 percent. Accordingly, the hollow tube segment can provide a desired level of hardness to the aerosol-generating article, comparable to that provided by conventional cellulose acetate hollow tube segments.

Optionally, the radial hardness of the hollow tube segment of the aerosol-generating article according to the invention is, for example, a plug wrap having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100 gsm, or at least about 110 gsm. Further increase can be achieved by surrounding the hollow tube segment with a hard plug wrap such as.

As used herein, the term "radial stiffness" refers to the resistance to compression transverse to the longitudinal axis of a hollow tube segment. The radial hardness of an aerosol-generating article about a hollow tube segment is determined by applying a load across the article in a direction transverse to the longitudinal axis of the article at the location of the hollow tube segment and the depressed diameter of the article. can be determined by measuring the average (mean value) of Radial hardness is given by:

where D _S is the original (undepressed) diameter and D _d is the depressed diameter after applying a set load for a set duration. Harder materials approach 100% hardness.

To determine the hardness of a portion of an aerosol-generating article (such as a hollow tube segment), the aerosol-generating article should be aligned in a plane and parallel, and the same portion of each aerosol-generating article to be tested should be held for a set duration. should be subjected to the set load during This test is carried out using the well-known DD60A Densimeter device (manufactured and marketed by Heinr. Borgwaldt GmbH, Germany), which is fitted with a measuring head for aerosol-generating articles such as cigarettes, and which is also equipped with an aerosol Comes with a container for generated items.

Loading is applied using two load-applying cylindrical rods that extend across the diameter of all the aerosol-generating articles at once. The standard test method for this instrument should be such that 20 contact points between the aerosol-generating article and the load-applying cylindrical rod are produced. In some cases, the hollow tube segments tested are such that only 10 aerosol-generating articles are required to form 20 contact points with each smoking article contacting both load application rods. Also, they may be long enough (because they are long enough to extend between both rods). In other cases, if the hollow tube segments are too short to accomplish this, 20 aerosol-generating articles should be used to form 20 contact points, as discussed further below. , each aerosol-generating article contacts only one of the load application rods.

Two additional fixed cylindrical rods are positioned below the aerosol-generating article to support the aerosol-generating article and to counteract the load imposed by each of the load-applying cylindrical rods.

For standard operating procedures for such devices, a total load of 2 kg is applied for 20 seconds. After 20 seconds have elapsed (and with the load still applied to the smoking article), the depression on the load-applying cylindrical rod is determined and then used to calculate the hardness from the above equation. The temperature is kept within the region of 22°C ± 2°C. The test described above is called the DD60A test. The standard method of measuring filter hardness is when the aerosol-generating article has not yet been consumed. Additional information regarding average radial hardness measurements can be found, for example, in US Published Patent Application Publication No. 2016/0128378.

Aerosol-generating articles according to the present invention may comprise one or more additional components that may be assembled with the rod of aerosol-generating substrate and with the hollow tube segment of the same wrapper.

Examples of such additional elements include mouthpiece filtering segments, cooling elements adapted to favor cooling of the aerosol before it reaches the mouthpiece, and the like.

As an example, the mouthpiece may include a filter segment, which is a plug of filtering material. The mouthpiece may, among other things, include a plug of fibrous filtering material. Suitable filtration materials are well known in the art and include fibrous filtration materials such as cellulose acetate tow, viscose fibers, polylactic acid (PLA) fibers and papers such as activated alumina, zeolites, molecular sieves and silica gels. including, but not limited to, adsorbents, as well as combinations thereof.

In some preferred embodiments, the fibrous filtration material used to form the mouthpiece is the same fibrous filtration material containing the PHA-containing polymer or copolymer described above for the hollow tube segments of the present invention. It can be material. This can be particularly advantageous because, in terms of biodegradability and absorption properties, the desirable effects associated with fibrous filtration materials comprising PHA-containing polymers or copolymers extend to mouthpiece plugs as well. As such, aerosol-generating articles can be provided that have particularly advantageous properties.

Additionally, the filter segment of the mouthpiece may further comprise one or more aerosol modifiers. Suitable aerosol modifiers are known in the art and include, but are not limited to, flavorants such as menthol.

In some embodiments, a hollow tube segment may be used at the downstream end of the aerosol-generating article, axially aligned with the mouthpiece filter segment, preferably adjacent the downstream end of the mouthpiece filter segment. good. In such embodiments, the hollow tube segment defines a mouth end recess downstream of the plug of filtration material. Thus, the hollow tube segment forms a cavity at the mouth end open to the outside environment at the downstream end of the aerosol-generating article.

In such embodiments, the filter segment of the mouthpiece may typically have a length of about 30 millimeters or less. Preferably, the length of the filter segment is about 27 millimeters or less. More preferably, the length of the filter segment is about 25 millimeters or less. Even more preferably, the length of the filter segment is about 20 millimeters or less.

In such embodiments, the length of the filter segment is preferably from about 5 millimeters to about 30 millimeters, more preferably from about 10 millimeters to about 30 millimeters, even more preferably from about 15 millimeters to about 30 millimeters, most preferably about 20 millimeters to about 30 millimeters. Alternatively, in such embodiments, the length of the filter segment is from about 4 millimeters to about 27 millimeters, preferably from about 5 millimeters to about 27 millimeters, more preferably from about 10 millimeters to about 27 millimeters, even more preferably It may be from about 15 millimeters to about 27 millimeters, most preferably from about 20 millimeters to about 27 millimeters. Still alternatively, in such embodiments, the length of the filter segment is from about 4 millimeters to about 25 millimeters, preferably from about 5 millimeters to about 25 millimeters, more preferably from about 10 millimeters to about 25 millimeters, even more preferably may be from about 15 millimeters to about 30 millimeters, most preferably from about 20 millimeters to about 25 millimeters.

The filter segment preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The filter segments preferably have an outer diameter of at least 5 millimeters. The filter segment may have an outer diameter of about 5 millimeters to about 12 millimeters, such as about 5 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters. In preferred embodiments, the filter segments have an outer diameter within the range of 7.2 millimeters to 10 percent.

In some embodiments, the mouthpiece comprises a single filter segment as described above. In other embodiments, the aerosol-generating article may comprise one or more additional filter segments. In some preferred embodiments, each of the filter segments of the mouthpiece comprises a PHA polymer or copolymer as described above.

Alternatively, a filter segment comprising a PHA polymer or copolymer may be combined with one or more axially aligned filter plugs formed of a fibrous filter material free of PHA-containing fibers. . Alternatively or additionally, filter segments comprising PHA polymers or copolymers may be combined with tubular elements formed from cardboard tubes.

The mouthpiece filter segment of an aerosol-generating article according to the invention may optionally contain a flavorant. Flavoring agents can be incorporated using a variety of different means, which will be well known to those skilled in the art. For example, flavorants may be incorporated in the form of capsules that may be provided in filter segments containing PHA polymers or copolymers.

For example, in one preferred embodiment, the aerosol-generating article comprises, in a linear continuous arrangement, a first plug of filtration material and a rod of aerosol-generating substrate positioned immediately downstream of the first plug of filtration material. a hollow tube segment as described above having a supporting function located immediately downstream of the rod; a second plug of filtering material located downstream of the hollow tube segment; the first plug, rod and support element; and an outer wrap surrounding the second plug.

The invention will now be further described with reference to the figures.

FIG. 1 shows a schematic longitudinal cross-section of an aerosol-generating article according to a first embodiment of the invention for use in an aerosol-generating device with a heater element. FIG. 2 shows a schematic longitudinal cross-sectional view of an aerosol-generating article according to a second embodiment of the invention with an integrated heat source. Figure 3 shows a schematic longitudinal cross-sectional view of an aerosol-generating article according to a third embodiment of the invention. FIG. 4 shows a schematic longitudinal cross-sectional view of an aerosol-generating system comprising an electrically-operated aerosol-generating device and the aerosol-generating article shown in FIG.

The aerosol-generating article 10 shown in FIG. 1 comprises a rod of aerosol-generating substrate 12, a support element 14 provided as a hollow tubular element, a cooling element 16, and a mouth end filter segment 18. FIG. These four elements are arranged in continuous and coaxial alignment and surrounded by substrate wrapper 20 to form aerosol-generating article 10 . Aerosol-generating article 10 has a mouth end 22 and a distal end 24 located at the opposite end of the article to mouth end 22 . The aerosol-generating article 10 shown in FIG. 1 is particularly suitable for use with an electrically operated aerosol-generating device that includes a heater for heating a rod of aerosol-generating substrate.

In use, air is drawn through the aerosol-generating article from the distal end 24 to the mouth end 22 by the user. The distal end 24 of the aerosol-generating article may also be described as the upstream end of the aerosol-generating article 10 and the mouth end 22 of the aerosol-generating article 10 may also be described as the downstream end of the aerosol-generating article 10. . Elements of the aerosol-generating article 10 located between the mouth end 22 and the distal end 24 can be described as being upstream of the mouth end 22, or alternatively downstream of the distal end 24. can be described as being in

Aerosol-generating substrate 12 is located at the farthest distal or upstream end of aerosol-generating article 10 . In the embodiment illustrated in FIG. 1, the aerosol-generating substrate 12 comprises an assembly of crimped, homogenized sheets of tobacco material surrounded by a wrapper. The crimped sheet of homogenized tobacco material contains glycerin as an aerosol former.

Support element 14 is located immediately downstream of aerosol-generating substrate 12 and abuts aerosol-generating substrate 12 . In the embodiment shown in Figure 1, the support element is a hollow tube formed of fibrous filtering material. The support element 14 positions the aerosol-generating substrate 12 at the farthest distal end 24 of the aerosol-generating article 10 so that it can be penetrated by the heating element of the aerosol-generating device. In practice, the support element 14 allows the aerosol-generating substrate 16 to be pushed downstream within the aerosol-generating article 10 toward the aerosol-cooling element 16 when the heating element of the aerosol-generating device is inserted into the aerosol-generating substrate 12 . It acts as a barrier to prevent Support element 14 also serves as a spacer to separate aerosol-cooling element 16 of aerosol-generating article 10 from aerosol-generating substrate 12 .

An aerosol cooling element 16 is located immediately downstream of the support element 14 and abuts the support element 14 . In use, volatiles emitted from the aerosol-generating substrate 12 pass along the aerosol-cooling element 16 toward the mouth end 22 of the aerosol-generating article 10 . Volatile substances may be cooled within the aerosol cooling element 16 to form an aerosol for inhalation by the user. In the embodiment shown in FIG. 1, the aerosol cooling element comprises tubular element 20 . A collection of crimped sheets of polylactic acid define a plurality of longitudinal channels extending along the length of the aerosol cooling element 40 .

A filter segment 18 is located immediately downstream of the aerosol cooling element 16 and abuts the aerosol cooling element 16 .

In the embodiment shown in FIG. 1, filter segment 18 comprises a single cylindrical plug of fibrous filtration material formed of a plurality of PHA fibers having approximately 3 denier per filament and approximately 27,000 total denier. The PHA fibers have a circular cross-sectional shape and are substantially longitudinally aligned with each other along the length of the filter segment. The exposed surface area of PHA fibers corresponds to about 0.16 square meters/gram. PHA fibers are formed by a melt spinning process and are crimped. The plug of fibrous filtration material is surrounded by a plug wrap (not shown).

Additionally, support element 14 is a hollow tube segment comprising a fibrous filtration material formed of a plurality of PHA fibers having approximately 3 denier per filament and approximately 27,000 total denier. The PHA fibers have a circular cross-sectional shape and are substantially longitudinally aligned with each other along the length of the filter segment. The exposed surface area of PHA fibers corresponds to about 0.16 square meters/gram. PHA fibers are formed by a melt spinning process and are crimped. More specifically, the fibers contain about 85 weight percent of a PHA polymer or copolymer combined with 15 weight percent of a PBAT/PBS blend having a 1:1 ratio of PBAT to PBS.

The aerosol-generating article 100 shown in FIG. 2 includes a combustible heat source 112 , a rod of aerosol-generating substrate 114 , a moving element 116 , an aerosol-cooling element 118 , a spacer element 120 and a mouthpiece filter segment 122 . These elements are arranged in continuous and coaxial alignment and surrounded by a substrate wrapper to form the aerosol-generating article 100 .

Combustible heat source 112 includes a substantially annular cylindrical body of carbonaceous material having a length of approximately ten millimeters. Combustible heat source 112 is a blind heat source. In other words, combustible heat source 112 does not have air channels extending therethrough.

A rod of aerosol-generating substrate 114 is disposed at the proximal end of combustible heat source 112 . Aerosol-forming substrate 114 comprises a substantially annular cylindrical plug 124 of tobacco material surrounded by filter plug wrap 126 .

A non-combustible, substantially impermeable first barrier 128 is disposed between the proximal end of combustible heat source 112 and the distal end of aerosol-generating substrate 114 . The first barrier 128 comprises a disk of aluminum foil. First barrier 128 also provides a thermally conductive member between combustible heat source 112 and aerosol-generating substrate 114 to conduct heat from the proximal surface of combustible heat source 112 to the distal surface of aerosol-generating substrate 114 . to form

Thermally conductive element 130 surrounds a proximal portion of combustible heat source 112 and a distal portion of aerosol-forming substrate 114 . Thermally conductive element 130 comprises a tube of aluminum foil. Thermally conductive element 130 is in direct contact with the proximal portion of combustible heat source 112 and filter plug wrap 126 of aerosol-generating substrate 114 .

Mouthpiece filter 122 comprises a single cylindrical plug 126 of fibrous filtration material formed of a plurality of PHA fibers having approximately 3 denier per filament and approximately 27,000 total denier. The PHA fibers have a circular cross-sectional shape and are substantially longitudinally aligned with each other along the length of the filter segment. The exposed surface area of PHA fibers corresponds to about 0.16 square meters/gram. PHA fibers are formed by a melt spinning process and are crimped. The plug of fibrous filtration material is surrounded by a plug wrap (not shown).

Spacer element 120 is provided as a hollow tube segment according to the present invention and comprises a fibrous filtration material formed of a plurality of PHA fibers having approximately 3 denier per filament and approximately 27,000 total denier. The PHA fibers have a circular cross-sectional shape and are substantially longitudinally aligned with each other along the length of the filter segment. The exposed surface area of PHA fibers corresponds to about 0.16 square meters/gram. PHA fibers are formed by a melt spinning process and are crimped. More specifically, the hollow tube segment has an inner diameter of about 3.30 millimeters and an outer diameter of about 7.10 millimeters, corresponding to a wall thickness of about 1.90 millimeters.

The aerosol-generating article 310 shown in FIG. 3 is a combustible smoking article that includes an aerosol-generating substrate 312 and a filter 314 disposed coaxially aligned with each other. Aerosol-generating substrate 312 comprises a tobacco rod surrounded by an outer wrapper (not shown). A tipping wrapper 316 surrounds both the filter 314 and the end portion of the aerosol-generating substrate 312 and attaches the filter 314 to the aerosol-generating substrate 312 .

Filter 314 comprises a cylindrical plug 318 of fibrous filtration material formed of PHA fibers having approximately 3 denier per filament and approximately 27,000 total denier. The PHA fibers have a circular cross-sectional shape and are substantially longitudinally aligned with each other along the length of the filter segment. The exposed surface area of PHA fibers corresponds to about 0.16 square meters/gram. PHA fibers are formed by a melt spinning process and are crimped. The plug of fibrous filtration material is surrounded by a plug wrap (not shown).

Additionally, filter 314 includes a hollow tube segment 320 disposed immediately downstream of plug 318 in axial alignment with plug 318 . Hollow tube segment 320 includes a fibrous filtration material formed of PHA fibers having approximately 3 denier per filament and approximately 27,000 total denier. The PHA fibers have a circular cross-sectional shape and are substantially longitudinally aligned with each other along the length of the filter segment. The exposed surface area of PHA fibers corresponds to about 0.16 square meters/gram. PHA fibers are formed by a melt spinning process and are crimped.

FIG. 4 shows a portion of an electrically operated aerosol-generating system 200 that utilizes a heater blade 210 for heating the rods of the aerosol-generating substrate 12 of the aerosol-generating article 10 shown in FIG. The heater blade 210 is mounted within an aerosol-generating article chamber within the housing of an electrically operated aerosol-generating device 212 . The aerosol-generating device 212 defines a plurality of air holes 214 for allowing air to flow to the aerosol-generating article 10, as illustrated by the arrows in FIG. Aerosol generator 212 includes a power supply and electronics, which are not shown in FIG.

Comparative Example [Incorporate discussion of Tests 1 and 2 from IDR? ]

PHA filter segments according to the present invention are prepared from PHA fibers with the parameters shown in Table 1 below. PHA fibers are formed using a melt spinning process, after which the fibers are crimped and formed into filter segments using standard filter manufacturing equipment. For comparison purposes, conventional cellulose acetate (CA) tow filter segments are prepared with similar values of denier per filament (dpf) and total denier.

The first test compares the water absorption of PHA filter segments according to the present invention and CA filter segments upon exposure to water. For each filter segment, the plug wrap is removed and the filter segment is attached to the probe of a mechanical tensiometer (KRUSS mechanical tensiometer, model K100). The filter segments are moved down towards the water container by the probe and automatically stop when the filter segments contact the water. The filter segment is held in contact with the water for 300 seconds to allow the filter material to absorb the water, then the filter segment is weighed to determine the amount of water absorbed during the test period. This test was repeated three times for each of the PHA and CA filter segments and the average water absorption was calculated as shown in Table 2 below.

Therefore, the amount of water absorbed by the PHA filter segments according to the invention during the test was less than 40 percent of the amount of water absorbed by the CA filter segments. This test therefore shows that the water affinity of the PHA filter segments according to the invention is significantly reduced compared to conventional CA filter segments.

A second test compares the water absorption of PHA filter segments according to the present invention and CA filter segments upon exposure to moisture. For each filter segment, the plug wrap is removed and the fibers forming the filter segment are placed in a petri dish and exposed to air at 22° C. and 50 percent relative humidity for 70 hours. This is performed on a Vapor Sorption Analyzer (ProUmid SPSx-1μ). For each filter segment, the fiber is weighed at the beginning of the test and the change in weight over time due to water vapor absorption by the fiber is determined. For each of the PHA and CA filter segments, the percentage difference in sample mass (% dm) values are calculated and the increase in sample weight is expressed as a percentage of the original weight. The %dm values for each sample at the end of the 70 hour test are shown in Table 3 below:

The results show that the amount of water vapor absorbed by the cellulose acetate fibers during the 70 hour test was over 50 times greater than the amount of water vapor absorbed by the PHA fibers. The PHA fibers absorbed very little water vapor during the test. This further demonstrates the significantly reduced affinity for water of the PHA filter segments according to the invention compared to conventional CA filter segments.

A third test compares the absorption of water from mainstream smoke by a PHA filter segment according to the invention and a conventional CA filter segment. For each of the filter segments, a conventional smoking article is prepared as described above with reference to Figure 3 using a combustible tobacco rod and a single segment of filter material to form the filter. Each of the smoking articles is then smoked in a cigarette smoking machine under ISO conditions described in ISO 3308:2000 (35 ml smoke volume, 2 second smoke duration every 60 seconds), and the resulting smoke Conduct analysis.

For each of the filter segments, measure the amount of water in the mainstream smoke collected during the smoking test, as shown in Table 4:

This is because, when smoked under comparable conditions, smoking articles incorporating PHA filter segments produce mainstream smoke with a moisture content approximately 20 percent higher than that of mainstream smoke from smoking articles containing CA filter segments. indicate that This indicates that the PHA filter segment does not absorb as much water from the mainstream smoke as the CA filter segment, thereby reducing the potential problem of dry smoke as described above.

Claims (15)

An aerosol-generating article for producing an inhalable aerosol when heated, said aerosol-generating article comprising:
a rod of aerosol-generating substrate;
a hollow tube segment comprising a fibrous filtration material disposed downstream of said rod and longitudinally aligned with said rod;
an aerosol wherein said fibrous filtration material comprises fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer and said hollow tube segments comprise at least about 25 weight percent of said PHA polymer or copolymer Generated goods. 2. The aerosol-generating article of claim 1, wherein the fibrous filtration material comprises at least about 85 weight percent fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer. 3. The aerosol-generating article of claim 1 or claim 2, wherein the fibrous filtration material comprises at least about 90 weight percent fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer. 4. The aerosol-generating article of any one of claims 1-3, wherein the fibrous filtration material comprises at least about 5% fibers comprising cellulose acetate. 5. The aerosol-generating article of claim 4, wherein the fibrous filtration material comprises at least about 10% fibers comprising cellulose acetate. The fibers comprising polyhydroxyalkanoic acid (PHA) polymers or copolymers are starch, polybutylene succinate (PBS), polybutyrate adipate terephthalate (PBAT), thermoplastic starch and thermoplastic starch blends (TPS), poly Caprolactone (PCL), polyglycolide (PGA), polyvinyl alcohol (PVOH/PVA), viscose, regenerated cellulose, polysaccharides, cellulose acetate with degree of substitution (DS) less than 2.1, polyamides, protein-based biopolymers , chitosan-chitin based biopolymers, and combinations thereof. 7. The aerosol-generating article of claim 6, wherein said at least one biodegradable polymer is one or more of PBAT, PCL and PBS. Claims 1-, wherein the fibrous filtration material comprises at least about 3 weight percent of a plasticizer selected from triacetin, triethylene glycol diacetate (TEGDA), ethylene vinyl acetate, polyvinyl alcohol, starch, or combinations thereof. 8. The aerosol-generating article according to any one of claims 7. The aerosol-generating article of any one of claims 1-8, wherein said fibers comprising a polyhydroxyalkanoic acid (PHA) polymer or copolymer have a denier per filament of 3.2 to 5. 10. The aerosol-generating article of any one of claims 1-9, wherein the fibers comprising polyhydroxyalkanoic acid (PHA) polymers or copolymers are crimped. 11. The aerosol-generating article of any one of claims 1-10, wherein the RTD of the filter segment is less than about 10 millimeters _H2O . The aerosol-generating article of any one of claims 1-11, wherein the hollow tube segment has a wall thickness of at least about 0.3 millimeters. 13. The aerosol-generating article of any one of claims 1-12, wherein the hollow tube segment has a wall thickness of about 1.5 millimeters or less. 14. The aerosol-generating article of any one of claims 1-13, wherein the hollow tube segment has a length of at least about 4 millimeters. The aerosol-generating article of any one of claims 1-14, wherein the hollow tube segment has a dry radial hardness of at least about 90 percent.

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