EP4240905B1 - Segment for a smoking article comprising a calendered fibre web - Google Patents

Description

FIELD OF THE INVENTION

The invention relates to a segment of a smoking article, wherein the segment comprises a filter material that allows the properties of the segment, in particular draw resistance and filtration efficiency, to be easily and reliably adjusted over a wide range. The filter material of the segment comprises a calendered fiber web with special properties.

BACKGROUND AND STATE OF THE ART

Smoking articles are typically rod-shaped articles consisting of at least two consecutively arranged rod-shaped segments. One segment contains a material capable of forming an aerosol when heated, and at least one other segment contains a material designed to influence the properties of the aerosol.

The smoking article may be a filter cigarette, in which a first segment contains the aerosol-forming material, in particular tobacco, and a further segment, designed as a filter, serves to filter the aerosol. The aerosol is generated by burning the aerosol-forming material, and the filter primarily serves to filter the aerosol and provide the filter cigarette with a defined draw resistance.

The smoking article can also be a so-called tobacco heater, in which the aerosol-forming material is only heated but not burned. This reduces the number and quantity of harmful substances in the aerosol. Such a smoking article also consists of at least two, but more often of more, in particular four, segments. One segment contains the aerosol-forming material, which typically includes tobacco, reconstituted tobacco, tobacco prepared using other methods, or nicotine and glycerol or propylene glycol. Other, sometimes optional, segments in the tobacco heater serve to conduct the aerosol, cool the aerosol, or filter the aerosol.

The segments are usually wrapped in a wrapping material. Paper is often used as the wrapping material.

It is known in the art to form such segments from cellulose acetate or polylactides. Since polylactides, and especially cellulose acetate, biodegrade very slowly in the environment, the industry has an interest in manufacturing the segments of smoking articles from other materials that are more biodegradable and, above all, allow the use of cellulose acetate to be avoided. It is known in the art to manufacture segments for smoking articles, in particular filter segments, from paper. While such segments are generally readily biodegradable, they also have disadvantages. For example, filter segments made of paper generally have a high filtration efficiency and therefore result in a dry aerosol, which impairs the taste of the aerosol compared to cigarettes with the usual filter segments made of cellulose acetate. Furthermore, they often have a lower filtration efficiency for phenols than cellulose acetate. In addition, it is proving difficult to produce a paper segment that meets consumer standards in terms of its combination of draw resistance, filtration efficiency, and hardness. To reduce filtration efficiency, less paper is often used per filter volume, which results in the segment becoming soft and having too low a draw resistance.

When designing the segments of a smoking product, draw resistance and filtration efficiency play a major role. Smoking products require segments with both high and low draw resistance, as well as high and low filtration efficiency. Because draw resistance and filtration efficiency are closely related, it has proven difficult to adjust these parameters independently over a wide range.

There is therefore an interest in the industry to have a filter material available that allows the production of segments in which the draw resistance and filtration efficiency can be changed independently of each other over a wide range.

DE 197 53195 A1 discloses a filter for tobacco products, in particular cigarettes, which is made from a cellulose fleece produced by an air-laid process.

DE 199 51062 A1 discloses a cigarette filter with mechanical disintegrability based on continuous cellulose ester fibers. The special feature of this cigarette filter is that the acetate weight/draw resistance ratio, based on the filament titer, exceeds a predetermined threshold.

US$3,346,682 discloses methods for producing a material for filtering tobacco smoke, in which a crystalline synthetic polymer is spun through a nozzle to to form a strand, the strand is intercepted as it exits the die by an oscillating surface arranged at an angle to the direction of travel of the strand to spread the strand into a web and direct the web downwards to a moving collecting surface, collecting the web on the collecting surface in overlapping, multi-directionally intersecting layers to form a sheet, calendering the sheet, cutting the pressed sheet into ribbons, feeding a ribbon into a gas jet, injecting a gas stream onto the plane of the ribbon and at an angle of between about 10° and 45° thereto to increase the cross-sectional area of the ribbon by at least five times and reduce its density, and collecting the bulked ribbon.

SUMMARY OF THE INVENTION

The invention is based on the object of providing a segment of a smoking article or for a smoking article whose draw resistance and filtration efficiency can be easily and reliably adjusted largely independently of each other and which is superior to conventional segments in this respect. A further object of the invention is to provide a readily biodegradable segment for smoking articles.

This object is achieved by a segment according to claim 1, a filter rod according to claim 12 and a smoking article according to claim 13. Advantageous further developments are specified in the dependent claims.

The inventors have found that this object can be achieved by a segment of a smoking article which comprises a wrapping material and a filter material, wherein the wrapping material wraps the filter material and the filter material is formed to at least 10% and at most 100% of its mass by a calendered fibrous web, and wherein at least 50% and at most 100% of the mass of the calendered fibrous web is formed by organic polymer fibers and wherein the calendered fibrous web has a compression factor of at least 0.45 and at most 0.85, wherein the compression factor is the ratio between the density of the calendered fibrous web and the volume-weighted density of the components of the calendered fibrous web.

According to the prior art, the skilled person would like the filter material in a segment of a smoking article to have a porous structure with a low density in order to provide the aerosol flowing through the segment with a sufficient surface area so that components of the aerosol can be efficiently filtered. For each filter material, the relationship between draw resistance and filtration efficiency is examined separately, and the type and mass of filter material in the segment are determined for the desired parameters. However, in addition to draw resistance and filtration efficiency, other aspects also play a role, in particular the hardness of the segment, which is determined primarily by the mass of the filter material and partly by the wrapping material. In particular, it has proven difficult to achieve low draw resistance and low filtration efficiency with sufficient hardness. It is also difficult to set low draw resistance and high filtration efficiency for a segment, or conversely, high draw resistance and low filtration efficiency. However, there is a great demand for such segments in smoking articles, particularly in tobacco heaters.

The inventors have surprisingly found that a calendered fiber web as a component of the segment in a smoking article can solve this problem. According to the prior art, a person skilled in the art would not consider a calendered fiber web for use as a filter material in a generic segment because they would assume that calendering would compact the fiber web, smooth and seal the surface, and thus create a non-porous structure that has very little filtration efficiency and makes such a fiber web unsuitable for segments in smoking articles. However, the inventors have found that, contrary to the expectations of the person skilled in the art, calendered fiber webs are suitable as a filter material for such segments if they are calendered such that their compression factor lies within the range according to the invention. In this narrow compression factor range, the surprising effect is that the tensile strength of a segment made from it is comparatively low, but the filtration efficiency is nevertheless in the medium range. In particular, the filtration efficiency is virtually independent of the tensile strength and the mass of the calendered fiber web in the segment and constant. A calendered fiber web with the compression factor according to the invention therefore allows the tensile strength or hardness of the segment to be adjusted without changing the filtration efficiency. This is not possible to the same extent with the filter materials available in the prior art.

The compression factor is the ratio of the density of the calendered fiber web to the volume-weighted density of the components of the calendered fiber web. This ratio essentially describes how strongly the fiber web is compressed. A compression factor of 1 represents maximum compression, meaning there is no pore volume in the calendered fiber web, while lower compression factors still retain pore volume in the calendered fiber web.

und die Dichte der kalandrierten Faserbahn ρ_c ergibt sich aus der flächenbezogenen Masse der Bestandteile und der Dicke d der kalandrierten Faserbahn durch $${\rho }_c=\frac{1}{d}{\displaystyle \sum _{i=1}^N{m}_i}.$$

If the fibrous web consists of i = 1,2,3, ... ,N components with the densities ρ _i and the masses per unit area m _i , then the volume-weighted density ρ _o of the components of the calendered fibrous web is calculated by $${\mathrm{<figure-callout\; id="0"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_0=\frac{{\displaystyle {\sum }_{i=1}^N{m}_i}}{{\displaystyle {\sum }_{i=1}^N\frac{m_i}{{\rho }_i}}}$$

and the density of the calendered fibrous web ρ _c is determined from the mass per unit area of the components and the thickness d of the calendered fibrous web by $${\rho }_c=\frac{1}{d}{\displaystyle \sum _{i=1}^N{m}_i}.$$

The basis weight can be determined according to ISO 536:2019 and the thickness according to ISO 534:2011. The compression factor C is then the ratio of the density of the calendered fiber web ρ _c and the density of the components of the fiber web ρ _o , i.e. $$C=\frac{{\mathrm{<figure-callout\; id="0"\; label="\rho \; c\; \rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_c}{{\rho }_{}}=\frac{1}{d}{\displaystyle \sum _{i=1}^N\frac{m_i}{{\rho }_i}}.$$

To achieve the effect according to the invention, the compression factor C must be at least 0.45 and at most 0.85. Calculating the compression factor C does not require the totality of all components. It is sufficient if the components used for the calculation together account for at least 90% of the mass of the calendered fiber web. Exemplary calculations of the compression factor are presented below.

The inventors have not yet found a theory as to why, contrary to expectations, a calendered fiber web exhibits a filtration efficiency in the mid-range and why, in the compression factor range according to the invention, the tensile resistance is decoupled from the filtration efficiency. However, as explained further below, it can be experimentally demonstrated that the compression factor of the calendered fiber web is the essential criterion for achieving the inventive effect. It can also be assumed that the porous structure and surface of the calendered fiber web created by calendering to the compression factor according to the invention are important.

The segment according to the invention comprises a filter material, wherein at least 10% and at most 100% of the mass of the filter material is formed by a calendered fiber web. The calendered fiber web allows the tensile strength and filtration efficiency to be adjusted independently of one another. For example, the proportion of the calendered fiber web in the filter material can be increased to increase the tensile strength but leave the filtration efficiency unchanged. Therefore, at least 20% and at most 90% of the Mass of the filter material is formed by the calendered fiber web, and more preferably at least 25% and at most 75% of the mass of the filter material. In some embodiments, the proportion of the calendered fiber web in the filter material is rather high, amounting to at least 30% and at most 100% of the mass of the filter material.

The compression factor of the calendered fiber web is essential for the segment according to the invention because, according to the inventors' findings, the tensile resistance and the filtration efficiency are decoupled only for a specific compression factor interval. The compression factor of the calendered fiber web is preferably at least 0.50 and at most 0.80, and particularly preferably at least 0.55 and at most 0.75. Within the inventive interval, the inventors' investigations show that tensile resistance and filtration efficiency are decoupled from each other; however, the calendering process can be carried out particularly efficiently within the preferred compression factor intervals.

In the segment according to the invention, the fiber web, which forms at least part of the filter material, is calendered. This can mean that the fiber web has passed through at least one roll nip during its production, in which mechanical pressure is exerted on the fiber web, thereby compressing and smoothing it. For example, the mechanical pressure and the number of roll nips can be selected such that the compression factor of the calendered fiber web lies within the range according to the invention. To support the calendering process, the rollers forming the roll nip can be heated and/or the moisture content of the fiber web can be adjusted before calendering. To produce the calendered fiber web for the segment according to the invention, it is important that the moisture content of the fiber web is increased during calendering compared to the equilibrium state of a dry fiber web in order to achieve a compression factor according to the invention. Furthermore, the person skilled in the art is able to adjust further parameters of the calendering process based on the properties of the fiber web so that the desired compression factor is achieved.

This calendering process must be distinguished from other processes, such as those in a size press or a coating unit, in which substances are applied to the surface of a fiber web. Although the fiber web may also pass through a roll nip, no significant pressure is exerted on the fiber web, so the fiber web is not compressed or is only slightly compressed, and the compression factor according to the invention is not achieved.

The calendered fiber web comprises organic polymer fibers. Organic polymer fibers are fibers consisting of polymers whose main chain contains carbon atoms. Such

Polymer fibers are, in principle, suitable for forming and calendering a fiber web, so that the invention can be realized with them.

Inorganic fibers such as glass fibers, metal fibers or mineral fibers and fibers made of inorganic polymers such as polysiloxanes are not included in the invention.

The biodegradability of the calendered fiber web can be improved or even enabled by the selection of organic polymer fibers. Since smoking articles are often disposed of in the environment after use, it is important that the segments that make up the smoking article are readily biodegradable.

The organic polymer fibers are therefore preferably fibers made from biopolymers. Biopolymers are polymers that are synthesized by living organisms or are chemically identical to polymers synthesized by living organisms. Modified polymers synthesized or synthesizable by living organisms are also biopolymers within the meaning of this invention. Synthetic polymers such as polyethylene or polypropylene, for example, are not biopolymers and are therefore less preferred but are in accordance with the invention. Preferably, at least 80% by weight, particularly preferably at least 90% by weight, and ideally all of the organic polymer fibers mentioned are fibers made from biopolymers.

To further optimize biodegradability, in a particularly preferred embodiment, the organic polymer fibers are fibers made from cellulose-based biopolymers. Examples of fibers made from cellulose-based biopolymers are cellulose fibers, fibers made from regenerated cellulose, and fibers made from cellulose acetate. Less preferred, but still in accordance with the invention, are fibers made from polylactides, which are a biopolymer but not a cellulose-based biopolymer and are less biodegradable than, for example, cellulose fibers. Likewise less preferred are fibers made from cellulose acetate, which are a cellulose-based biopolymer but are even less biodegradable than fibers made from polylactides.

In order to achieve the best biodegradability of the segment according to the invention, in a particularly preferred embodiment, the said fibers made of biopolymers are pulp fibers, fibers made of regenerated cellulose or a mixture thereof.

In particular, at least 80% by weight, preferably at least 90% by weight, and in particular all of the said organic polymer fibers are cellulose fibers obtained from coniferous trees, deciduous trees, or other plants such as hemp, flax, jute, ramie, kenaf, kapok, coconut, abaca, sisal, bamboo, cotton, or esparto grass, or a mixture of cellulose fibers from two or more of these trees or plants. In other words, the cellulose fibers can be obtained from exactly one of the above-mentioned sources. It can be either a mixture of pulp fibers obtained from two or more of the above-mentioned sources. In addition to optimal biodegradability, the fibers are also available in consistent quality and large quantities.

The proportion of organic polymer fibers in the calendered fiber web can vary. According to the invention, it is at least 50% and at most 100% of the mass of the calendered fiber web in order to impart strength to the fiber web favorable for further processing. However, the proportion of organic polymer fibers in the mass of the calendered fiber web is preferably higher, amounting to at least 60% and at most 100%, and particularly preferably at least 70% and at most 95%. A higher proportion of organic polymer fibers allows the fiber web to be calendered with less pressure in order to achieve the compression factor according to the invention.

For good biodegradability, it is preferred if the calendered fibrous web contains less than 40%, more preferably less than 30%, and most preferably less than 20% cellulose acetate fibers, with the percentages referring to the mass of the calendered fibrous web. In particular, the calendered fibrous web is free of cellulose acetate fibers.

The calendered fibrous web may contain filler. Filler creates a porous structure in the fibrous web and is generally not very compressible, so calendering the fibrous web requires higher pressure to achieve the desired compression factor. The filler content is therefore preferably at least 0% and at most 50% of the mass of the calendered fibrous web, more preferably at least 0% and at most 30%, and most preferably at least 0% and at most 5%, each based on the mass of the calendered fibrous web. The filler can be useful for increasing the whiteness of the fibrous web. This can be particularly important if the segment made from it is located at one end of the smoking article and its cross-sectional area is visible. The filler can also be used because it is cheaper than organic polymer fibers. For these reasons, a filler content of at least 5% and at most 35% based on the mass of the calendered fibrous web is also preferred.

Preferably, the filler is selected from the group consisting of calcium carbonate, magnesium carbonate, titanium dioxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide, magnesium silicate, aluminum silicate, kaolin, talc, and bentonite, or formed by a mixture of two or more of these filler types.

The calendered fibrous web may contain additives to impart special properties to the calendered fibrous web. These additives can, for example, influence the strength in the dry or wet state, water absorption, and filtration efficiency overall or for individual substances. The proportion of additives in the calendered fibrous web is preferably at least 0% and at most 10% of the mass of the calendered fibrous web, more preferably at least 1% and at most 9% of the mass of the calendered fibrous web.

The additives are preferably selected from the group consisting of sizing agents, alkyl ketene dimers (AKD), alkenyl succinic anhydrides (ASA), fatty acids, starch, starch derivatives, carboxymethylcellulose, alginates, chitosan, wet strength agents, citrates, trisodium citrate, tripotassium citrate, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxylates, salicylates, α-hydroxycaprylates, phosphates, polyphosphates, chlorides, hydrogen carbonates, triacetin, propylene glycol, ethylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, triethyl citrate, catalysts, activated carbon, flavorings, encapsulated flavorings and mixtures thereof.

The basis weight of the calendered fiber web is preferably at least 15 g/m ² and at most 44 g/m ² , preferably at least 20 g/m ² and at most 40 g/m ² , and particularly preferably at least 23 g/m ² and at most 38 g/m ² , in particular at least 31 g/m ² and at most 37 g/m ² . This basis weight is advantageous for facilitating the calendering of the fiber web and the further processing of the calendered fiber web into the segment of a smoking article, and it can impart favorable strength to the calendered fiber web. The data refer to a basis weight measured according to ISO 536:2019.

The thickness of the calendered fiber web is preferably at least 15 µm and at most 55 µm, more preferably at least 20 µm and at most 50 µm, and most preferably at least 30 µm and at most 37 µm. The thickness can be measured according to ISO 534:2011 and refers to the thickness of the fiber web after calendering.

The mechanical properties of the calendered fiber web are important for processing into a segment for a smoking article. The width-related tensile strength of the calendered fiber web, measured according to ISO 1924-2:2008, is preferably at least 6 N/15 mm and at most 70 N/15 mm, particularly preferably at least 8 N/15 mm and at most 60 N/15 mm.

The elongation at break of the calendered fiber web is important because when the fiber web is processed into a segment of a smoking article, the fiber web is often crimped and A particularly high elongation at break is advantageous. The elongation at break of the calendered fiber web, measured according to ISO 1924-2:2008, is therefore preferably at least 0.8% and at most 3.0%, and particularly preferably at least 1.0% and at most 2.5%.

Tensile strength and elongation at break may depend on the direction in which the sample was taken from the filter material for measurement. However, due to calendering, this directional dependence is minimal. The aforementioned characteristics of the calendered fiber web are met if the tensile strength or elongation at break lie within the specified preferred or particularly preferred intervals in at least one direction.

The inventors have also discovered that a coating can enhance the effectiveness of calendering and achieve an even better decoupling of tensile strength and filtration efficiency, especially when the basis weight of the calendered fiber web is low. A coating also allows the surface of the fiber web to be modified, for example, to achieve selective filtration of certain aerosol substances.

The coating can be applied in the form of a composition comprising the coating material and a solvent, with the solvent being removed after application, for example, by drying. Only those components of the composition that remain on the calendered fiber web are considered to be the coating.

In a preferred embodiment of the segment, the calendered fibrous web is coated on at least one side, wherein the coating on at least one side covers at least 20% and at most 100% of the area of this side of the calendered fibrous web, and wherein the coating comprises a material selected from the group consisting of sizing agents, alkyl ketene dimers (AKD), alkenyl succinic anhydrides (ASA), fatty acids, starch, starch derivatives, carboxymethylcellulose, alginates, chitosan, wet strength agents, citrates, trisodium citrate, tripotassium citrate, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxylates, salicylates, α-hydroxycaprylates, phosphates, polyphosphates, chlorides, hydrogen carbonates, triacetin, propylene glycol, ethylene glycol, sorbitol, Glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, triethyl citrate, catalysts, activated carbon, flavorings, and encapsulated flavorings or wherein the coating comprises a mixture of two or more of these materials.

In a particularly preferred embodiment, the coating comprises a material selected from the group consisting of starch, starch derivatives, cellulose derivatives and Mixtures thereof. Most preferably, the coating comprises a material selected from the group consisting of starch, starch derivatives, cellulose derivatives, and mixtures thereof (i.e., the material is a mixture of two or more of these substances), and the proportion of this material in the coating is at least 20% and at most 100%, preferably at least 50% and at most 100%, more preferably at least 70% and at most 98%, and most preferably at least 80% and at most 95%, in each case based on the mass of the coating applied to the calendered fibrous web.

In a particularly preferred embodiment, only one side of the calendered fiber web is coated, and the coating covers at least 50% and at most 100% of the surface area of the coated side of the calendered fiber web, and very particularly preferably at least 90% and at most 100% of the surface area of the coated side of the calendered fiber web, in particular, if, for example, one wishes to refrain from coating the entire surface of the fiber web for technical reasons, at least 80% and at most 95% of the surface area of the coated side of the calendered fiber web. Such technical reasons may be that part of the calendered fiber web should remain uncoated in order to be able to determine the properties of the fiber web without the coating on the finished fiber web.

In a particularly preferred embodiment, the calendered fiber web is coated on both sides and the coating covers at least 20% and at most 100% of the area of each of the two sides of the calendered fiber web and very particularly preferably at least 50% and at most 100% of the area of each of the two sides of the calendered fiber web, in particular at least 90% and at most 100% of the area of each of the two sides of the calendered fiber web, or, if, for example, for technical reasons, one wishes to refrain from coating the fiber web over the entire area, at least 80% and at most 95% of the area of each of the two sides of the calendered fiber web.

The amount of coating material applied to one side or both sides of the calendered fiber web is particularly preferably at least 0.5 g/m ² and at most 5.0 g/m ² , most preferably at least 0.7 g/m ² and at most 4.0 g/m ² , wherein the amount in g/m ² refers only to the area to which the coating material is actually applied.

In a preferred embodiment of the segment, the calendered fibrous web is coated on at least one side, wherein the coating on at least one side covers at least 20% and at most 100% of the area of this side of the calendered fibrous web, and the basis weight of the calendered fibrous web including coating is at least 20 g/m ² and at most 35 g/m ² . In a particularly preferred embodiment of this segment, the coating comprises a material selected from the group consisting of starch, starch derivatives, cellulose derivatives, and mixtures of two or more thereof.

The calendered fibrous web is preferably a calendered paper or a calendered nonwoven. Such preferred calendered fibrous webs can be produced using methods known in the art.

The segment according to the invention comprises a filter material, wherein at least 10% of the mass of the filter material is formed by the calendered fiber web. The filter material can be formed entirely by the calendered fiber web. However, the purpose of the calendered fiber web is primarily to decouple the segment's tensile resistance from the filtration efficiency. To fulfill this purpose, at least 10% of the mass of the filter material must be formed by the calendered fiber web. However, it is advantageous to combine the calendered fiber web with additional filtration material.

In a preferred embodiment, the filter material of the segment according to the invention comprises the calendered fiber web and a further filtration material, wherein the further filtration material is preferably selected from the group consisting of filter papers, nonwovens or tows and combinations thereof.

Particularly preferably, the additional filtration material is selected from the group consisting of filter papers, cellulose-based nonwovens, wet-needled nonwovens, tows comprising cellulose acetate, tows comprising regenerated cellulose, and combinations of two or more thereof. These additional filtration materials allow for particularly effective influence on the filtration efficiency of the segment.

In a particularly preferred embodiment, the additional filtration material is a filter paper, a cellulose-based nonwoven, a wet-needled nonwoven, or a combination of two or more of these. These additional filtration materials exhibit good biodegradability and can therefore be particularly advantageously combined with the calendered fiber web. In a further development of this particularly preferred embodiment, the additional filtration material is web-shaped and laminated to the calendered fiber web.

Preferably, at least 10% and at most 90% and particularly preferably at least 20% and at most 70% of the mass of the filter material is formed by the further filtration material.

In a particularly preferred embodiment, which combines the effect of the calendered fiber web on the draw resistance and the filtration efficiency with the biodegradability of the segment in a particularly advantageous manner, the segment of a smoking article comprises a wrapping material and a filter material, wherein the wrapping material wraps the filter material and at least 70% and at most 100% of the mass of the filter material is formed by a calendered fiber web, and wherein at least 50% and at most 100% of the mass of the calendered fiber web is formed by organic polymer fibers and wherein the calendered fiber web has a compression factor of at least 0.45 and at most 0.85 and at most 30% and in particular at most 20% of the mass of the filter material is formed by cellulose acetate.

The segment according to the invention for a smoking article comprises the filter material and a wrapping material, wherein the wrapping material wraps the filter material and is preferably a paper or a film.

The wrapping material must be strictly distinguished from the calendered fiber web, which is a component of the filter material. The wrapping material of a segment for a smoking article has completely different requirements, such as processability through bonding, air permeability, color, suitability for perforation, and, in some cases, printability. Filtration properties and the effect on draw resistance are irrelevant.

The wrapping material of the segment according to the invention preferably has a basis weight of at least 20 g/m ² and at most 150 g/m ² , particularly preferably of at least 30 g/m ² and at most 130 g/m ² . A wrapping material with this preferred or particularly preferred basis weight imparts a particularly advantageous hardness to the wrapped segment according to the invention, in combination with the filter material. This prevents the smoker from accidentally compressing the segment contained in the smoking article.

In a preferred embodiment of the segment according to the invention, the segment is cylindrical with an approximately circular or oval outer boundary of the cross-sectional area with a nominal diameter of this boundary of at least 3 mm and at most 10 mm, particularly preferably of at least 4 mm and at most 9 mm and most preferably of at least 5 mm and at most 8 mm. These nominal Diameters are favorable for the use of the segments according to the invention in smoking articles. The nominal diameter can be determined according to ISO 2971:2013.

In a preferred embodiment of the segment according to the invention, the segment has a length of at least 4 mm and at most 40 mm, particularly preferably of at least 6 mm and at most 35 mm and most preferably of at least 10 mm and at most 28 mm.

The draw resistance of the segment determines, among other things, the pressure difference the smoker must apply when consuming the smoking article to generate a certain volume flow through the smoking article, and therefore significantly influences the smoker's acceptance of the smoking article. The draw resistance of the segment can be measured according to ISO 6565:2015 and is expressed in mm water column (mmWG). To a very good approximation, the draw resistance of the segment is proportional to the length of the segment, so the draw resistance can also be measured on rods that differ from the segment only in length. From this, the draw resistance of the segment can be easily calculated.

The tensile resistance of the segment per length of the segment is preferably at least 0.05 mmWG/mm and at most 12.0 mmWG/mm, more preferably at least 0.1 mmWG/mm and at most 10.0 mmWG/mm and most preferably at least 0.1 mmWG/mm and at most 4.0 mmWG/mm.

The segment typically has a substantially cylindrical shape with an approximately circular or oval outer cross-sectional area and may have one or more cavities inside it, for example to accommodate activated carbon particles or breakable capsules containing flavorings. The cavities may also be formed as one or more elongated tubes that run at least approximately parallel to the longitudinal axis of the segment and are located entirely within the segment or terminate at one or both end surfaces of the segment. Such cavities can also influence filtration efficiency and draw resistance. The direction of the longitudinal axis corresponds to the flow direction of the aerosol in the smoking article when the smoker draws on the smoking article during use.

The segment according to the invention may also contain an aerosol-forming material, in particular a tobacco material.

The production of a segment according to the invention can be carried out according to the methods known in the prior art.

The filter rod according to the invention is cylindrical with an approximately circular or oval outer boundary of the cross-sectional area, has a length of at least 40 mm and at most 200 mm and comprises at least one segment according to the invention.

The filter rod preferably comprises at least one segment according to the invention and at least one further segment comprising a filter material, wherein the segments are arranged one after the other in the longitudinal direction of the filter rod. Particularly preferably, the filter material of the further segment comprises cellulose acetate.

The filter rod preferably comprises a plurality of segments according to the invention and a plurality of further, mutually similar segments, wherein the number of segments according to the invention and the number of further, mutually similar segments in the filter rod are the same, and one segment according to the invention and one further segment are arranged alternately one after the other in the longitudinal direction of the filter rod. In a particularly preferred embodiment of this filter rod, the number of segments according to the invention and the number of further, mutually similar segments is two, three, four, five, or six, respectively.

Such a filter rod, referred to as a "dual filter", allows the advantageous properties of the segment according to the invention to be combined with another segment which, in addition to its filtration properties, also ensures a good visual appearance of the mouth end of a smoking article made from the filter rod.

Preferably, the filter rod is cylindrical with an approximately circular or oval outer boundary of the cross-sectional area and a nominal diameter of at least 3 mm and at most 10 mm, more preferably at least 4 mm and at most 9 mm, and most preferably at least 5 mm and at most 8 mm. The nominal diameter can be determined according to ISO 2971:2013.

The production of a filter rod according to the invention can be carried out by methods known in the prior art.

The smoking article according to the invention comprises at least two segments, wherein one of the segments is a segment according to one of the embodiments described above and at least one of the segments contains an aerosol-forming material.

The inventors have found that the segments according to the invention can be used particularly advantageously in smoking articles which comprise at least three segments, wherein a first segment contains an aerosol-forming material, a second segment is a segment according to one of the embodiments described above and a third segment can serve for filtration, and wherein the second segment is arranged between the first and the third segment.

By combining the second segment with the third segment, an even wider range of filtration efficiencies and draw resistances can be covered, and the filtration efficiency can be even more closely matched to that of conventional filters, such as those made of cellulose acetate. The desired filtration efficiency is achieved by combining the second and third segments, and the draw resistance can then be adjusted by the amount of calendered fiber web in the second segment without significantly changing the filtration efficiency. Such a smoking article can be manufactured, for example, from the filter rod referred to above as a "dual filter."

In a preferred embodiment, the smoking article therefore comprises at least three segments, wherein a first segment contains an aerosol-forming material, a second segment is a segment according to one of the embodiments described above, and wherein the second segment is arranged between the first and the third segment. In a particularly preferred embodiment of this smoking article, the draw resistance of the third segment is higher than that of the second segment. In a particularly preferred embodiment of this smoking article, the ratio of the length of the second segment to the length of the third segment is at least 1:2 and at most 5:1, particularly preferably at least 1:1 and at most 3:1. The length of the segments influences the draw resistance, so that the draw resistance can be adjusted even better by choosing the length.

In a particularly preferred embodiment of this smoking article, the third segment comprises a filter paper, a cellulose-based nonwoven, a wet-needled nonwoven, a tow comprising cellulose acetate or a tow comprising regenerated cellulose.

In a preferred embodiment, the smoking article is a filter cigarette and the aerosol-forming material comprises tobacco.

The segment according to the invention is particularly well suited for smoking articles in which the aerosol-forming material is only heated but not burned during intended use. Such smoking articles often consist of several, typically two to four, segments, with one segment containing the aerosol-forming material and the other segments containing the These segments can be used for transferring, cooling, or filtering the aerosol. These segments require highly varying draw resistances and filtration efficiencies, so there is a particular need for such smoking articles to be able to easily and reliably adjust the draw resistance and filtration efficiency of a segment over a wide range.

In a preferred embodiment, the smoking article is therefore a smoking article in which, during its intended use, the aerosol-forming material is only heated but not burned. The aerosol-forming material comprises a material selected from the group consisting of tobacco, reconstituted tobacco, nicotine, glycerol, propylene glycol, and flavorings, or a mixture of two or more of these materials. Particularly preferably, the aerosol-forming material is electrically heated. The aerosol-forming material can also be in gel or liquid form and can preferably be contained in a container in a segment of the smoking article.

Both the segment according to the invention and a smoking article according to the invention can be produced by methods known from the prior art.

SHORT DESCRIPTION OF THE FIGURE

Fig. 1

shows a diagram of the filtration efficiency for nicotine as a function of the draw resistance for segments according to the invention and according to the prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS AND SOME COMPARATIVE EXAMPLES

In the following, some preferred embodiments of a segment according to the invention are described and compared with examples not according to the invention.

Calculating the compression factor

An exemplary fiber web of a segment according to the invention with a basis weight of 32 g/m ² , the basis weight of which consists of m ₁ = 27.0 g/m ² cellulose fibers, with the density ρ ₁ = 1.5 g/cm ³ , of m ₂ = 3.2 g/m ² calcium carbonate particles, with the density ρ ₂ = 2.7 g/cm ³ and the remaining mass of further additives, has in the sense of this invention a volume-weighted density ρ _o of the components of $${\mathrm{<figure-callout\; id="0"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_0=\frac{m_1+m_2}{\frac{m_1}{{\rho }_1}+\frac{{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png"\; state="\{\{state\}\}">m</figure-callout>}}_2}{{\mathrm{<figure-callout\; id="2"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_2}}=\frac{27,0+3,2}{\frac{27,0}{1,5}+\frac{3,2}{2,7}}=1,574\frac{g}{{\mathit{cm}}^3}.$$

The other additives were neglected because their influence on the density is small.

If a calendered fiber web with a thickness of d = 28 µm is produced from these components, the compression factor C is $$C=\frac{{\rho }_c}{{\mathrm{<figure-callout\; id="0"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_0}=\frac{1}{d}\left(\frac{m_1}{{\rho }_1}+\frac{{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png"\; state="\{\{state\}\}">m</figure-callout>}}_2}{{\mathrm{<figure-callout\; id="2"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_2}\right)=\frac{1}{28}\left(\frac{27,0}{1,5}+\frac{3,2}{2,7}\right)=0,685.$$

Another exemplary fiber web of a segment according to the invention with a basis weight of 25 g/m ² , whose mass per unit area consists of m ₁ = 22.5 g/m ² polyethylene fibers, with the density ρ ₁ = 0.95 g/cm ³ , of m ₂ = 2.0 g/m ² titanium dioxide particles, with the density ρ ₂ = 4.2 g/cm ³ and the remaining mass of further additives, has in the sense of this invention a density ρ _o of the components of $${\mathrm{<figure-callout\; id="0"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_0=\frac{m_1+m_2}{\frac{m_1}{{\rho }_1}+\frac{{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png"\; state="\{\{state\}\}">m</figure-callout>}}_2}{{\mathrm{<figure-callout\; id="2"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_2}}=\frac{22,5+2,0}{\frac{22,5}{0,95}+\frac{2,0}{4,2}}=1,014\frac{g}{{\mathit{cm}}^3}.$$

The other additives were neglected because their influence on the density is small.

If a calendered fiber web with a thickness of d = 30 µm is produced from these components, the compression factor C is $$C=\frac{{\rho }_c}{{\mathrm{<figure-callout\; id="0"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_0}=\frac{1}{d}\left(\frac{m_1}{{\rho }_1}+\frac{{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png"\; state="\{\{state\}\}">m</figure-callout>}}_2}{{\mathrm{<figure-callout\; id="2"\; label="\rho "\; filenames="imgf0001.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_2}\right)=\frac{1}{30}\left(\frac{22,5}{0,95}+\frac{2,0}{4,2}\right)=0,805$$

The densities of the components of the calendered fiber web are generally known from the state of the art. Table 1 shows some typical values. Table 1 density g/ ^cm3 cellulose 1.5 Regenerated cellulose 1.5 Cellulose acetate 1.3 Polylactide 1.2 - 1.4 Polyethylene 0.9 - 1.0 Polypropylen 0.9 Calcium carbonate 2.7 Titanium dioxide 4.2 talc 2.6 - 2.8

Production of the calendered fiber web Calendered fiber web A

A pulp fiber mixture consisting of 80% spruce and pine pulp fibers and 20% birch pulp fibers was used to produce the calendered fiber web. The spruce and pine pulp fibers were refined to a freeness of 67 °SR, measured according to ISO 5267-1:1999. Starch was added to the fiber web so that it consisted of approximately 95% pulp fibers and 5% starch. The fiber web was produced on a conventional paper machine and calendered in a calender integrated into the paper machine at elevated moisture levels.

The density of the components, neglecting the starch, was ρ _o = 1.5 g/m ² .

The basis weight was 35 g/m ² and the thickness 33 µm, therefore the compression factor is $$C=\frac{1}{35}\left(\frac{35\cdot 0,95}{1,5}\right)=0,672.$$

The tensile strength and elongation at break of the calendered fiber web A were determined according to ISO 1924-2:2008, with a value of 51.6 N/15 mm for the tensile strength in the machine direction and 1.1% for the elongation at break in the machine direction.

The fiber web was also calendered more and less intensively, resulting in different thicknesses and compression factors, as shown below in Table 3.

Calendered fiber web B

Regenerated cellulose fibers were refined to a freeness of 73°SR, measured according to ISO 5267-1:1999. The fibers were formed into a fiber web on a paper machine using suitable processing aids, so that the fiber web consisted of approximately 99% of its mass from regenerated cellulose fibers. The fiber web was calendered in a calender integrated into the paper machine at elevated moisture levels.

The density of the components was therefore ρ _o = 1.5 g/cm ³ .

The basis weight was 42 g/m ² and the thickness 38 µm, therefore the compression factor is $$C=\frac{1}{38}\left(\frac{42\cdot 0,99}{1,5}\right)=0,729.$$

The tensile strength and elongation at break of the calendered fiber web B were determined according to ISO 1924-2:2008, with a value of 61.7 N/15 mm for the tensile strength in the machine direction and 1.0% for the elongation at break in the machine direction.

Relationship between draft resistance and filtration efficiency

Cylindrical filter rods with a length of 108 mm and a diameter of approximately 7.1 mm were manufactured from the calendered fiber webs A and B. The filter material of the filter rods was formed entirely by the calendered fiber web and wrapped in a suitable wrapping material with a basis weight of 78 g/ ^m² . The width of the fiber web used to manufacture the filter rods varied between 60 mm and 242 mm, allowing different amounts of filter material to be present in the filter rod to vary the tensile strength. The length of the calendered fiber web used to manufacture the filter rods was approximately 108 mm.

Filter cigarettes were made from the 108 mm long filter rods. The filter rods, cut into 18 mm long segments, served as filter segments in the filter cigarette. The tobacco blend of the filter cigarettes was an American Blend , and the filter cigarettes differed, within the usual production tolerances, only in the filter segment.

die Filtrationseffizienz für Nikotin berechnet. Sie kann als Prozentsatz ausgedrückt werden und beschreibt das Verhältnis der im Filter zurückgehaltenen Menge an Nikotin zu der in den Filter einströmenden Menge an Nikotin.As a characteristic parameter for the filtration efficiency, the filtration efficiency for nicotine was measured. For this purpose, the filter cigarettes were smoked according to the procedure specified in ISO 3308:2012 and both the mass of nicotine exiting the mouth end (m) and the mass of nicotine contained in the filter segment (m _Filter ) were determined and divided by $${\mathrm{m}}_{\mathrm{Filter}}/\left(\mathrm{m}+{\mathrm{m}}_{\mathrm{Filter}}\right)$$

The filtration efficiency for nicotine is calculated. It can be expressed as a percentage and describes the ratio of the amount of nicotine retained in the filter to the amount of nicotine flowing into the filter.

Table 2 shows the used fiber web width (W), the draw resistance (PD), and the filtration efficiency (FE) for nicotine for an 18 mm long segment made from the calendered fiber webs A and B.

These results were compared with filters made of paper that was very similar to calendered fiber web A in terms of composition and basis weight but not calendered, and cellulose acetate. The results are shown in Fig. 1 The diagram in Fig. 1 shows the draw resistance (PD) of an 18 mm long segment in mmWG on the horizontal axis and the filtration efficiency (FE) for nicotine in % on the vertical axis. Values are shown for segments made from calendered fiber web A (circles), calendered fiber web B (crosses), non-calendered filter paper (triangles), and cellulose acetate (square). One can see the surprising effect that for the segments made from calendered fiber webs A and B, the filtration efficiency does not change with increasing draw resistance within the measurement tolerances, whereas it increases significantly for the segments made from non-calendered filter paper and cellulose acetate. The comparison between the segments from the calendered fiber web A (circles) and from the non-calendered filter paper (triangles) shows that calendering and the resulting compression factor is an essential feature to decouple tensile resistance and filtration efficiency. Table 2 Fibrous web W PD FE [mm] [mmWG] [%] A 40 1.2 37.3 A 79 9.2 37.1 A 119 27.8 39.7 A 159 46.4 36.4 B 60 1.8 56.8 B 121 14.1 56.1 B 181 42.3 54.6 B 242 70.7 55.4

Influence of the compression factor

bestimmt.In order to determine in which range of the compression factor of the calendered fiber web the tensile resistance and the filtration efficiency are essentially decoupled, a fiber web with the composition of fiber web A was tested at different settings of the calender, resulting in different thicknesses and densities of the calendered fiber web. 108 mm long filter rods were manufactured from a 40 mm and a 159 mm wide calendered fiber web and cut into 18 mm long segments. The draw resistance of the segments, Δp ₄₀ for the 40 mm wide fiber web and Δp ₁₅₉ for the 159 mm wide fiber web, and the filtration efficiency for nicotine of the segments, F ₄₀ for the 40 mm wide fiber web and F ₁₅₉ for the 159 mm wide fiber web, were determined as described above, and from this, an average rate of change in the filtration efficiency for nicotine was calculated based on the change in draw resistance by $$\left({\mathrm{F}}_{159}-{\mathrm{<figure-callout\; id="40"\; label="F"\; filenames="imgf0001.png"\; state="\{\{state\}\}">F</figure-callout>}}_{40}\right)/\left({\mathrm{\Delta p}}_{159}-{\mathrm{<figure-callout\; id="40"\; label="\Delta p"\; filenames="imgf0001.png"\; state="\{\{state\}\}">\Delta p</figure-callout>}}_{40}\right)$$

certainly.

The results are given in Table 3, where for comparison an analogously determined mean rate of change of the filtration efficiency for nicotine for the segment from the non-calendered filter paper (Y), ρ _o = 1.5 g/cm ³ , and from cellulose acetate (Z) from the data of Fig.1 Table 3 shows the thickness (D), compression factor (C), and mean rate of change of nicotine filtration efficiency (ΔF/ΔP). Table 3 material D C ΔF/ΔP [µm] [%/mmWG] A 48 0.462 0.33 A 41 0.541 0.08 A 33 0.672 -0.02 A 27 0.821 0.03 A 25 0.887 0.15 Y 52 0.426 0.46 Z --- --- 0.45

Table 3 shows that within a compression factor range of approximately 0.45 to approximately 0.85 for the calendered fiber web, the draw resistance and filtration efficiency for nicotine are largely decoupled. Although the average rate of change in filtration efficiency (ΔF/ΔP) is still low even at a compression factor above 0.85, the pressure required for calendering is already very high, so it is advantageous to select a compression factor no higher than 0.85.

In connection with Table 2, the data for the calendered fiber web B also shows that a decoupling of tensile resistance and filtration efficiency is largely occurs regardless of the composition of the calendered fiber web. The compression factor interval according to the invention therefore applies regardless of the composition of the fiber web.

Effect of the coating Calendered fiber web C

A fiber web with a basis weight of 23 g/ ^m² was produced from a pulp fiber blend consisting of 45% spruce and pine pulp fibers and 55% eucalyptus pulp fibers. The spruce and pine pulp fibers were refined to a freeness of 94 °SR, measured according to ISO 5267-1:1999. The fiber web was produced on a conventional paper machine, then fully coated on both sides with starch in a separate coating device, and calendered in another device at elevated moisture content to obtain calendered fiber web C.

The amount of starch applied to both sides together by the coating was approximately 1.5 g/m ² , i.e. 6.12% of the mass of the calendered fiber web, resulting in a basis weight of 24.5 g/m ² .

The density of the components, neglecting the starch, was ρ _o = 1.5 g/cm ³ .

A thickness of 20 µm results in a compression factor of $$C=\frac{1}{20}\left(\frac{24,5\cdot 0,9388}{1,5}\right)=0,767.$$

The tensile strength and elongation at break of the calendered fiber web C were determined according to ISO 1924-2:2008, with a value of 29 N/15 mm for the tensile strength in the machine direction and 2.0% for the elongation at break in the machine direction.

A calendered fiber web D was produced in the same way, but without coating.

Filter rods with a length of 108 mm were produced from the calendered fiber webs, using calendered fiber web C in widths of 120 mm and 220 mm and calendered fiber web D in widths of 120 mm and 180 mm to produce four different segments. The length of the calendered fiber web was consistent in all In these cases, the filter rod length was approximately 108 mm. The filter rods were wrapped with a wrapping material with a basis weight of 78 g/ ^m² . As for fiber webs A and B, the filtration efficiency for nicotine was determined, and Table 4 shows the width (W) of the calendered fiber web, the draw resistance (PD) of an 18 mm long segment, and the filtration efficiency (FE) for nicotine. Table 4 Fibrous web W PD FE [mm] [mmWG] [%] C 120 5.9 29.3 C 220 22.5 30.8 D 120 2.9 35.9 D 180 6.7 37.4

While the filtration efficiency of the inventive segments produced from the calendered fiber web D still depends somewhat on the tensile strength and changes at a rate of change of (37.4 - 35.9)/(6.7 - 2.9) = 0.39%/mmwg, this rate of change for the inventive segments produced from the coated and calendered fiber web C is only (29.3 - 30.8)/(22.5 - 5.9) = 0.09%/mmwg. This shows that the coating allows for an even better decoupling of tensile strength and filtration efficiency.

A comparison of these change rates of segments from the calendered fiber webs A and B, with a basis weight of 35 g/m ² and 42 g/m ² respectively, with segments from the calendered fiber webs C and D, with a basis weight of 24.5 g/m ² and 23 g/m ² respectively, also shows that the positive effect of calendering is lower with a lower basis weight of the calendered fiber web and that this effect can be well compensated by a coating.

Combination with filtration material

Starting with an 18 mm long filter segment made of cellulose acetate with a draw resistance of approximately 30 mmWG and a filtration efficiency for nicotine of 22.4%, the mass of cellulose acetate was reduced and a 79 mm wide, calendered fiber web A was added to the filter material. The 18 mm long segment then had a draw resistance of approximately 15 mmWG and a filtration efficiency of 22.8%. This demonstrates that with the segment according to the invention, it is possible to reduce the draw resistance by approximately half and keep the filtration efficiency for nicotine approximately constant. If one wishes to achieve such a reduction in draw resistance without the use of the calendered fiber web A, both the filtration efficiency for nicotine would be too low and the hardness of the filter segment would be insufficient.

The results therefore show that the segment according to the invention can offer great advantages in adjusting the draw resistance and filtration efficiency taking into account the hardness of the segment and that additional improvements in biodegradability can also be achieved.

Smoking articles made up of three segments

A filter cigarette F according to the invention with a length of 83 mm and a diameter of 7.8 mm was produced, consisting of three segments. The first segment contained an American Blend tobacco blend, the second segment was a segment according to the invention made of the calendered fiber web C, and the third segment contained a filter paper. The second segment was arranged between the first and third segments, and the third segment formed the mouth end of the filter cigarette.

The second segment was 18 mm long with a tensile strength of 22 mmWG, while the third segment was 9 mm long and had a tensile strength of 46 mmWG.

The filter paper in the third segment was a paper consisting essentially of 100% cellulose fibers with a basis weight of 35 g/m ² and a thickness of 88 µm.

As a non-inventive comparative example, a filter cigarette X with a diameter of 83 mm, a diameter of 7.8 mm, an American Blend tobacco blend, and a 27 mm long filter segment made of cellulose acetate was produced. The filter segment had a draw resistance of 84 mmWG.

The filter cigarette F according to the invention and the filter cigarette X serving as a comparative example not according to the invention contained the same mass of tobacco and were ventilated by a perforation in the area of the filter, the degree of ventilation being adjusted so that both filter cigarettes had an open draw resistance of approximately 110 mmWG.

Both filter cigarettes were smoked according to the procedures standardized in ISO 3308 and ISO 4387 and the total particulate phase (TPM), nicotine and carbon monoxide (CO), as well as the number of puffs (PC) were determined.

The values shown in Table 5 were obtained. Table 5 TPM nicotine CO PC cigarette mg/cig mg/cig mg/cig F 10.7 0.68 13.6 7.8 X 10.5 0.70 13.4 7.7

These data demonstrate that by combining the segment according to the invention with another segment serving as a filtration element, the smoke output can be very well adapted to an otherwise identical filter cigarette with a cellulose acetate filter. In addition to the flexibility in adjusting the draw resistance and filtration efficiency, this also results in significant ecological advantages because the poorly biodegradable cellulose acetate can be dispensed with.

Claims (15)

1. Segment for a smoking article, which comprises a wrapper material and a filter material, wherein the wrapper material wraps the filter material and at least 10% and at most 100% of the mass of the filter material is formed by a calendered fibrous web, wherein at least 50% and at most 100% of the mass of the calendered fibrous web is formed by organic polymer fibers, characterized in that the calendered fibrous web has a compression factor C of at least 0.45 and at most 0.85,
   wherein the compression factor is calculated by $$C=\frac{1}{d}{\displaystyle \sum _{i=1}^N\frac{m_i}{{\rho }_i}}$$

   

   wherein d is the thickness of the calendered fibrous web determined in accordance with ISO 534:2011, m_i,

   with 1≤i≤N, is the mass per unit area of the i-th of N≥1 components of the calendered fibrous web,

   and ρ_i, with 1≤i≤N, is the density of the i-th of the N≥1 components,

   wherein the N components considered for the calculation of the compression factor C are selected such that the sum of the masses per unit area m_i from i=1 to i=N is at least 90% of the basis weight of the calendered fibrous web determined in accordance with ISO 536:2019.
2. Segment according to claim 1, in which at least 20% and at most 90%, preferably at least 25% and at most 75% or at least 30% and at most 100% of the mass of the filter material is formed by the calendered fibrous web, and/orin which the compression factor of the calendered fibrous web is at least 0.50 and at most 0.80, preferably at least 0.55 and at most 0.75.
3. Segment according to one of the preceding claims, in which at least 80% by weight, preferably at least 90% by weight and in particular all of the organic polymer fibers are fibers from biopolymers, wherein said fibers produced from biopolymers are preferably fibers from cellulose-based biopolymers, and in particular pulp fibers, fibers from regenerated cellulose or fibers from cellulose acetatewherein said fibers from biopolymers are formed by pulp fibers, fibers from regenerated cellulose or a mixture thereof,or in which at least 80% by weight, preferably at least 90% by weight and in particular all of said organic polymer fibers are formed by pulp fibers that are sourced from coniferous trees, deciduous trees, hemp, flax, jute, ramie, kenaf, kapok, coconut, abacá, sisal, bamboo, cotton or esparto grass, or are formed by a mixture of pulp fibers from two or more of these trees or plants.
4. Segment according to one of the preceding claims, in which the proportion of organic polymer fibers with respect to the mass of the calendered fibrous web is at least 60% and at most 100%, preferably at least 70% and at most 95%, and/or in which the calendered fibrous web contains less than 40%, preferably less than 30% and particularly preferably less than 20% fibers from cellulose acetate, each with respect to the mass of the calendered fibrous web, and in particular is free from fibers produced from cellulose acetate.
5. Segment according to one of the preceding claims, in which the calendered fibrous web contains filler material, wherein the proportion of filler material with respect to the mass of the calendered fibrous web is at least 0% and at most 50%, preferably at least 0% and at most 30% and particularly preferably at least 0% and at most 5%, or wherein the proportion of filler material with respect to the mass of calendered fibrous web is between 5% and 35%, wherein the filler material is preferably selected from the group consisting of calcium carbonate, magnesium carbonate, titanium dioxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide, magnesium silicate, aluminum silicate, kaolin, talcum, bentonite, or is formed by a mixture of two or more of these types of filler material, and/or in which preferably at least 0% and at most 10% of the mass of the calendered fibrous web, preferably at least 1% and at most 9% of the mass of the calendered fibrous web is formed by one or more additives selected from the group consisting of sizing agents, alkylketene dimers (AKD), alkenyl succinic acid anhydrides (ASA), fatty acids, starch, starch derivatives, carboxy methyl cellulose, alginates, chitosan, wet strength agents, citrates, trisodium citrate, tripotassium citrate, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxalates, salicylates, α-hydroxy caprylates, phosphates, polyphosphates, chlorides, hydrogen carbonates, triacetin, propylene glycol, ethylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, triethyl citrate, catalysts, activated carbon, flavors and encapsulated flavors.
6. Segment according to one of the preceding claims, in which the basis weight of the calendered fibrous web is at least 15 g/m² and at most 44 g/m², preferably at least 20 g/m² and at most 40 g/m², particularly preferably at least 23 g/m² and at most 38 g/m², in particular at least 31 g/m² and at most 37 g/m², and/or in which the thickness of the calendered fibrous web is at least 15 µm and at most 55 µm, preferably at least 20 µm and at most 50 µm, particularly preferably at least 30 µm and at most 37 µm, and/or in which the tensile strength with respect to width of the calendered fibrous web, measured in accordance with ISO 1924-2:2008, in at least one direction is at least 6 N/15 mm and at most 70 N/15 mm, preferably at least 8 N/15 mm and at most 60 N/15 mm, and/or in which the elongation at break of the calendered fibrous web, measured in accordance with ISO 1924-2:2008, in at least one direction is at least 0.8% and at most 3.0%, preferably at least 1.0% and at most 2.5%.
7. Segment according to one of the preceding claims, in which the calendered fibrous web is coated on at least one side, wherein the coating on at least one side covers at least 20% and at most 100% of the surface area of this side of the calendered fibrous web, and the coating material comprises a material selected from the group consisting of sizing agents, alkylketene dimers (AKD), alkenyl succinic acid anhydrides (ASA), fatty acids, starch, starch derivatives, carboxy methyl cellulose, alginates, chitosan, wet strength agents, citrates, trisodium citrate, tripotassium citrate, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxalates, salicylates, α-hydroxy caprylates, phosphates, polyphosphates, chlorides, hydrogen carbonates, triacetin, propylene glycol, ethylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, triethyl citrate, catalysts, activated carbon, flavors and encapsulated flavors or comprises a mixture of two or more of these materials, in which the coating comprises preferably a material that is selected from the group consisting of starch, starch derivatives, cellulose derivatives or a mixture of at least two of these substances, wherein the proportion of this material in the coating is preferably at least 20% and at most 100%, particularly preferably at least 50% and at most 100%, more particularly preferably at least 70% and at most 98% and in particular at least 80% and at most 95%, each with respect to the mass of the coating that is applied to the calendered fibrous web.
8. Segment according to claim 7, in which only one side of the calendered fibrous web is coated and the coating covers at least 50% and at most 100%, preferably at least 90% and at most 100% and particularly preferably at least 80% and at most 95% of the area of the coated side of the calendered fibrous web, or wherein the calendered fibrous web is coated on both sides and the coating covers at least 20% and at most 100%, preferably at least 50% and at most 100%, particularly preferably at least 90% and at most 100% or at least 80% and at most 95% of the surface area of both sides of the calendered fibrous web, wherein the amount of coating material that is applied to one or both sides of the calendered fibrous web is at least 0.5 g/m² and preferably at most 5.0 g/m², preferably at least 0.7 g/m² and at most 4.0 g/m², wherein the amount in g/m² is with respect to the surface area to which the coating material is actually applied, and/or the calendered fibrous web is preferably coated on at least one side, wherein the coating covers on at least one side at least 20% and at most 100% of the area of this side of the calendered fibrous web, and the basis weight of the calendered fibrous web including the coating is at least 20 g/m² and at most 35 g/m², wherein the coating preferably comprises a material that is selected from the group consisting of starch, starch derivatives, cellulose derivatives and mixtures of two or more thereof, and/or in which the calendered fibrous web is preferably a calendered paper or a calendered nonwoven.
9. Segment according to one of the preceding claims, in which the filter material comprises the calendered fibrous web and a further filtration material, wherein the further filtration material is preferably selected from the group consisting of filter papers, nonwovens, tows or combinations thereof, wherein the further filtration material is preferably selected from the group consisting of filter papers, cellulose-based nonwovens, hydroentangled nonwovens, tows comprising cellulose acetate, tows comprising regenerated cellulose and combinations of two or more thereof, and/or in which the further filtration material is preferably a filter paper, a cellulose-based nonwoven, a hydroentangled nonwoven or a combination of two or more thereof, wherein the further material is preferably web-shaped and is laminated to the calendered fibrous web, and/or in which preferably at least 10% and at most 90%, particularly preferably at least 20% and at most 70%, of the mass of the filter material is formed by the further filtration material.
10. Segment according to one of the preceding claims, in which at least 70% and at most 100% of the mass of the filter material is formed by the calendered fibrous web and wherein at most 30%, preferably at most 20% of the mass of the filter material is formed by cellulose acetate, and/or in which the wrapper material is a paper or a film, and/or in which the wrapper material has a basis weight of at least 20 g/m² and at most 150 g/m², preferably at least 30 g/m² and at most 130 g/m².
11. Segment according to one of the preceding claims, wherein the segment is cylindrical with an approximately circular or oval outer boundary of the cross sectional surface and has a nominal diameter of at least 3 mm and at most 10 mm, preferably at least 4 mm and at most 9 mm and particularly preferably at least 5 mm and at most 8 mm, and/or wherein the segment has a length of at least 4 mm and at most 40 mm, preferably at least 6 mm and at most 35 mm and particularly preferably at least 10 mm and at most 28 mm, and/or the draw resistance per unit length of the segment is at least 0.05 mmWG/mm and at most 12.0 mmWG/mm, preferably at least 0.1 mMWG/mm and at most 10.0 mmWG/mm and particularly preferably at least 0.1 mmWG/mm and at most 4.0 mmWG/mm, and/or which has one or more cavities in its interior, wherein activated carbon particles or breakable capsules with flavors are contained in the at least one or more cavities, or wherein the one or more cavities is or are shaped as elongated tube(s), which are at least approximately parallel to a longitudinal axis of the segment and are located entirely within the segment or terminate at one or both end surfaces of the segment. and/or wherein the segment contains an aerosol-forming material, in particular a tobacco material.
12. Filter rod, wherein the filter rod is cylindrical with an approximately circular or oval outer boundary of the cross sectional surface, has a length of at least 40 mm and at most 200 mm and comprises at least one segment according to one of claims 1 to 11, wherein the filter rod comprises preferably at least one segment according to one of claims 1 to 11 and at least one further segment with a filter material, wherein the segments are arranged one after the other in the longitudinal direction of the filter rod, and wherein the filter material of the further segment preferably comprises cellulose acetate, wherein the filter rod preferably comprises a plurality of segments according to one of claims 1 to 11 and a plurality of further segments which are identical to each other, wherein in the filter rod, the number of segments according to one of claims 1 to 11 is equal to the number of the further segments which are identical to each other in the filter rod and in the longitudinal direction of the filter rod, a segment according to one of claims 1 to 11 and a further segment are arranged in alternation one after the other, wherein the number of segments according to one of claims 1 to 11 and the number of the further segments identical to each other is respectively two, three, four, five or six, and/or wherein the filter rod is preferably cylindrical with an approximately circular or oval outer boundary of the cross sectional surface and has a nominal diameter of at least 3 mm and at most 10 mm, preferably at least 4 mm and at most 9 mm and particularly preferably at least 5 mm and at most 8 mm.
13. Smoking article which comprises at least two segments, wherein one of the segments is a segment according to one of claims 1 to 11 and at least one of the segments contains an aerosol-forming material.
14. Smoking article according to claim 13, which comprises at least three segments, wherein a first segment contains an aerosol-forming material, a second segment is a segment according to one of claims 1 to 11, and a third segment is provided, wherein the third segment in particular serves for filtration, and wherein the second segment is arranged between the first and the third segment, wherein the draw resistance of the third segment is preferably higher than that of the second segment, and/or in which the ratio of the length of the second segment to the length of the third segment is preferably at least 1:2 and at most 5:1, preferably at least 1:1 and at most 3:1, and/or in which the third segment preferably comprises a filter paper, a cellulose-based nonwoven, a hydroentangled nonwoven, a tow comprising cellulose acetate or a tow comprising regenerated cellulose.
15. Smoking article according to one of claims 13 or 14, wherein the smoking article is a filter cigarette and the aerosol-forming material is tobacco, orwherein the aerosol-forming material is only heated but not burned during the intended use of the smoking article and the aerosol-forming material comprises a material that is selected from the group consisting of tobacco, reconstituted tobacco, nicotine, glycerol, propylene glycol, and flavors or a mixture of two or more of these materials, wherein the aerosol-forming material is preferably heated electrically during the intended use and/or wherein the aerosol-forming material is present as a gel or in liquid form and is preferably contained in a container in a segment of the smoking article.

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