Title - FILTER ELEMENT FOR FILTER MOUTHPIECES, FILTER MOUTHPIECE FOR USE WITH SMOKING PRODUCTS OR HNB PRODUCTS AND CIGARETTE FILTER

Abstract

The invention relates to a filter element for filter mouthpieces for use with smoking products or HNB products, wherein the filter element has a filter body made of a fiber material, wherein the fiber material is formed from a plurality of intertwined and wavy cellulose acetate filament monofilaments, wherein the cellulose acetate filaments in particular have a multilobular or polygonal cross-sectional geometry and preferably Y-shaped. It is therefore envisaged that the cellulose acetate filaments of the fiber material have a uniform filament count, which in particular is predefined or definable, in a range of less than or equal to 10 deniers (11.1 dtex) and more than or equal to 5 deniers (5.5 dtex), and that the fiber material has a total count in a range of less than or equal to 10.000 deniers (11.1 kdtex) and more or equal to 5000 deniers (5555.5 dtex), and that the specific fiber weight of the cellulose acetate filaments of the fiber material is less than or equal to 2.5 mg per mm of filter element length and greater than or equal to 1.0 mg per mm of filter element length.

Description

FILTER ELEMENT FOR FILTER MOUTHS, FILTER MOUTH FOR USE WITH SMOKING PRODUCTS OR HNB PRODUCTS AND CIGARETTE FILTER Description The invention relates to a filter element for a filter mouthpiece for use with smoking products or HNB products, as well as to the use of such a filter element in filter mouthpieces for use with smoking products or in cigarette filters or filter mouthpieces for HNB products, respectively. Smoking products, within the meaning of the present invention, refer to traditional tobacco products, cigarettes in particular, but also to pipes and marijuana products, as well as so-called heat-not-burn (HNB) tobacco products, vaping products, and so-called hybrid products. Depending on the application, filter mouthpieces for use with smoking products have different functions. For example, filter mouthpieces can, on the one hand, function as filter devices to expel harmful components from a tobacco smoke stream, such as condensed substances, particularly tar, as well as particulate matter entrained in the smoke stream. The filtering function is particularly used with conventional tobacco applications. Thus, a filter mouthpiece can be formed as an integral part of a cigarette or cigarillo and thus "serve as a support" in the cigarette / cigarillo. An example of another type of filter mouthpiece relates to interchangeable devices, such as replaceable filter elements that can be removed after use. Such filter mouthpieces are arranged in suitable holders, e.g., a cigarette holder or a pipe holder. A filter mouthpiece formed as an integral part of a cigarette is the cigarette filter. The cigarette filter is intended to reduce a percentage of harmful substances, such as condensate and gas present in cigarette smoke. In addition, the filter makes the smoke smoother or more pleasant. 2154744 of 21, a pleasant experience for a large percentage of smokers. In a conventional filter cigarette, the filter is wrapped in filter paper and connected to the tobacco wick by means of a so-called tipping paper, which provides a filter to most industrially manufactured cigarettes. There are numerous types of filter materials already in use, particularly for reducing the substances present in tobacco smoke before they reach the smoker's respiratory system. However, in addition to removing large amounts of harmful substances, a satisfactory filter must also be effective without undesirably impeding the passage of air or smoke through the filter and, therefore, without requiring excessive puffing. When using tobacco smoke filters, the filter material must not, however, also change the taste of tobacco smoke by adding its own flavor. The present invention relates not only to filter materials for the above-mentioned conventional tobacco applications, but also in particular to filter materials and / or filter elements for filter mouthpieces used in smoking products, whereby these particular filter elements have other functions than a mere filtration function. Therefore, the materials required to form a filter mouthpiece for use with smoking products need to be adapted, and in particular adaptable, to the physical properties of the smoke (temperature, flow profile, etc.) and its chemical composition. Both conventional cigarette filters and HNB products in particular have a number of objective parameters that need to be regulated or met, respectively, by the appropriate selection and configuration of the filter mouthpiece materials. This refers in particular to the following objective parameters, which will be briefly discussed below: • suction resistance • filtration performance 2154744 of 21 • Filter hardness / Filterona hardness • Visual appearance Filter hardness is an important objective criterion for cigarette filters. This is usually indicated as the so-called Filtrona hardness. Filtrona hardness is determined by vertically pressing the flat end face of a 12 mm diameter cylindrical rod against a horizontally positioned filter with a load of 300 g. The ratio of the compressed diameter to the initial diameter previously determined during the first contact results in the Filtrona hardness percentage. It should be noted that Filtrona hardness is only measured on a filter, but not on the underlying (raw) filter material. Filtrona hardness is particularly influenced by the triacetin sprayed onto all cigarette filters. The minimum Filtrona hardness limit is approximately 88% and is geared toward market requirements. Therefore, the Filtrona hardness of the cigarette filter can preferably be set to approximately 88% to 95%, in particular approximately 90% to 93%. In conventional cigarette filters, Filtrona hardness is essentially determined by the fiber weight per unit volume for a given filter diameter. In particular, the filament count has only a minor influence on Filtrona hardness. Occasionally, higher Filtrona hardness can also be achieved by using a stronger filter wrapping paper or tipping paper. Tipping paper is a paper that is either joined together by fitting several filter elements together, or that is used to attach filter elements to the tobacco wick. However, increasing Filtrona hardness by using stronger filter wrapping paper or tipping paper has economic disadvantages, as higher costs are expected. Related to Filtrona hardness is the so-called "hot collapse," where the filter hardness decreases over time while smoking. This 2154744 of 21 can occur particularly with a traditional cigarette when the filter heats up in the presence of moisture during one of the last puffs. This undesirable effect can also occur with HNB products. In addition to a Filtrona hardness, which is as constant and high as possible throughout the use of a smoking product, the filter mouthpiece material must also have a predefined or definable filtration performance. Filtration performance regarding condensed matter (droplets, particles), also referred to as condensate or tar, is of interest with respect to conventional tobacco products as well as HNB products, since condensed matter contains a variety of substances of unhealthy importance. In conventional products, filtration performance is selected (along with other influencing factors such as tobacco blend, ventilation, etc.) to regulate cigarette "delivery" (the concentration of smoke components within the direct smoke). In many markets, the legal regime caps "delivery" at an upper limit. Below the legal limit, "delivery" can be tailored to consumer preferences. In HNB products, the aerosol contains much less condensed matter of negative health significance than in conventional products. However, since the condensate also contains more desirable materials, such as flavorings and nicotine, the goal here is to select the lowest possible filtration efficiency, but without letting it drop to zero. Regarding the objective parameter "draw resistance," it should be noted that consumers show a preference for a certain draw resistance range when using a tobacco product. In conventional cigarettes, the filter (in addition to regulating "delivery") serves to regulate the resistance to drawing the cigarette. In HNB products, however, the suction resistance provided by the mouth-side filter (nozzle with filter) should tend to be as low as possible. 2154744 of 21 possible, since the other components of the HBN device, particularly the heated tobacco section and the device, already contribute a high level of draw resistance. A low draw resistance through the filter (filter mouthpiece) results in degrees of freedom relative to the other components of the HBN device, which is desirable. Although suction resistance and filtration performance are closely linked, both can be reduced in a variety of ways, although this often negatively affects other parameters. For example, suction resistance and filtration efficiency can be reduced by reducing the filter length. However, once the filter length becomes shorter than the filter diameter, processability becomes problematic. A smaller filter also results in a shorter cooling section, which is problematic for thermal equilibrium. Alternatively or additionally, suction resistance and filtration efficiency can be reduced by reducing the fiber weight in the filter material by volumetric content and / or the total value. This, however, has the disadvantage that the Filtrona hardness decreases, and it may no longer be possible to achieve the minimum hardness. Alternatively or additionally, suction resistance and filtration performance can be reduced with increasing filament count. With a constant filter diameter and a fixed fiber weight per unit volume, filtration performance and suction resistance decrease with increasing filament count, which is desirable for HNB products compared to conventional products. Hardness is also not negatively affected, since, as stated above, Filtrona hardness is only marginally dependent on filament count. Regarding the objective parameter "visual appearance," it should be noted that consumers prefer a mouthpiece with a flat, white cross-sectional area on the mouth side. However, there are also products that take the shape of a tube on the mouth side. 2154744 of 21 While conventional cigarette filters, which are usually made of cellulose acetate filaments, ensure optimal filtration of smoke components, these filter materials can often only be used to a limited extent in other applications, especially in the case of HNB products or e-cigarettes, since in these applications, the filter materials or, respectively, the filter mouthpiece materials must perform other functions. HNB products, like conventional smoking products, generally have the disadvantage that the user inhales the inhaled aerosol at a high temperature. This is sometimes unpleasant for the user. Particularly with HNB products, the filter mouthpiece materials therefore serve the purpose of cooling the aerosol with the lowest possible filtration efficiency. But even in the case of traditional cigarettes, particularly so-called thin or ultra-thin cigarettes, i.e., cigarettes with a small diameter, e.g., 5.0 mm to 6.5 mm, the filter / filter mouthpiece materials must provide, compared to filter materials for extra-large cigarettes, a lower filtration efficiency, greater cooling, and better tactile properties (a firm but not too rigid grip). Naturally, there is less smoke / flavor during burning than with an extra-large cigarette. The low filtration efficiency is sought so as not to further reduce the flavor. If the amount of filter material is reduced only for this purpose, the filter's hardness will ultimately be unsatisfactory. With the same fiber density, fine or ultra-fine cigarette filters also have significantly higher draw resistance than extra-large filters, which is generally undesirable. For both HNB products and fine or ultra-fine cigarettes, it has been proposed to increase the filament titer while maintaining the total titer to achieve the desired reduced filtration performance in terms of 2154744 of 21 condensable components such as tar, as well as sufficient filter hardness. However, this approach has several disadvantages. Currently, 2.5-cellulose acetate is widely used in the production of filter rods for filter elements, respectively, cigarette filters. From a smoking and health perspective, it has demonstrably exceptional properties in relation to specific retention phenomena. A filter made of cellulose acetate filters harmful nitrosamines and phenols much more effectively than condensate and nicotine. Smokers also find the flavor of blended tobacco smoke combined with a cellulose acetate filter element to be the most palatable. Another advantage of a filter element made with 2.5-cellulose acetate that should not be overlooked is the visual uniformity of the filter's cut surfaces. However, despite their undeniable market dominance, 2.5 cellulose acetate filter elements have some significant disadvantages: Filter rods have a suction resistance and filtration performance explicitly defined by structural physical stipulations. The particle filtration or even condensate retention of a normal 2.5 cellulose acetate filter element is a function of the filament count (fiber fineness), filter diameter, suction resistance and filter length. Given a typical filter diameter of 7.8 mm and a filter length of 21 mm to 25 mm, this becomes problematic when a filter efficiency significantly higher than 50% is required during the production of filter elements, as is necessary when designing ultra-light cigarettes. The same can be said, figuratively, of filter elements in the case of fine or ultra-fine cigarettes. Since the smoke in a filter element flows parallel to the fiber direction, such a filter element can only be obtained by significantly reducing the filament titer, which 2154744 of 21 which would simultaneously result in a significant increase in aspiration resistance without any change in total titer. Therefore, the total titer and the filament titer must be reduced equally, resulting in a dramatic decrease in the hardness of the filter element, especially during smoking. Experts refer to this phenomenon as "hot collapse," and it is generally considered undesirable. The present invention aims to specify a filter element specifically for so-called thin or ultra-thin cigarettes; i.e., cigarettes with a small diameter, e.g., 5.0 mm to 6.5 mm, where the filter element exhibits sufficient filter hardness despite the low filtration efficiency and increased cooling. Furthermore, the filter element should be able to achieve adjustable and, in particular, reduced draw resistance compared to extra-large filters. The invention solves this task with a filter element having the features of independent claim 1, whereby further advantageous embodiments of the inventive filter element are specified in the dependent claims. Accordingly, the invention relates in particular to a filter element for filter mouthpieces for use with smoking products or HNB products, wherein the filter element has a filter body made of a fiber material. The fiber material is formed by a plurality of interlaced and crimped cellulose acetate filament monofilaments, whereby the cellulose acetate filaments in particular have a multilobular or polygonal, and preferably Y-shaped, cross-sectional geometry. The filter element according to the invention is characterized in particular by a specific filament count selected for the cellulose acetate filaments of the fiber material. The filament count is preferably in a range of less than or equal to 10 deniers and greater than or equal to 5 deniers. 2154744 of 21 Furthermore, a relatively small total titer is selected for the fiber material of the inventive filter element, preferably a total titer in a range of less than or equal to 10,000 deniers to more than or equal to 5,000 deniers. Surprisingly, it was found herein that despite the relatively low filament titer, less than or equal to 10 deniers, and the relatively low total titer, less than or equal to 10,000 deniers, the totally undesired phenomenon of hot collapse can be effectively avoided even in the case of thin or ultra-thin cigarettes when a relatively low titer, less than or equal to 2.5 mg per mm of filter element length, is selected for the fiber specific gravity of the cellulose filaments of the fiber material; i.e. for the so-called acetate specific gravity. With the characteristics of the relatively low filament titer, the relatively low total titer, and the relatively low specific gravity of the fibers in cellulose acetate filaments (acetate weight), a filter element can be produced that achieves the filter performance required in the design of thin or ultra-thin cigarettes without significantly increasing draw resistance. These parameters make it possible to significantly increase the performance and range of applications achievable with the filter element. In particular, the cellulose acetate filaments of the fiber material exhibit an at least partially trilobular shape; i.e., a star-shaped cross-section with three faces. Such a cross-sectional shape is very suitable when the cellulose acetate filaments must have the largest possible specific surface area to enable high filtration capacity, if desired, as is the case with conventional cigarettes, for example, while simultaneously utilizing economical raw materials. Alternatively, it is possible to obtain a large desired specific surface area with a bundle of extremely fine filaments of, for example, circular cross-section. However, other methods are also conceivable. 2154744 of 21 cross-sectional shapes for cellulose acetate filaments, such as, for example, a multilobular, polygonal or X-shaped cross-sectional shape. The fiber material of the inventive filter element is formed by continuous crimped cellulose acetate filaments in a stuffing box. Thus, a solution of approximately 30% cellulose acetate in acetone is pressed into spinnerets, the acetone is evaporated in a spinning chamber, a plurality of cellulose acetate filaments (5,000 to 10,000) are gathered into a strip, and then crimped in a stuffing box. After this, the product is dried, filled into storage containers, and finally pressed into bales weighing between 300 kg and 600 kg. After the filter fiber bales have been transported to the cigarette or filter manufacturer, the filter fiber is removed from the bales and processed into filter rods on a filter machine. The filter fiber is then stretched in a stretching device, given an additive that serves to bind the filaments, and, after forming a three-dimensional spinning fiber, is then introduced through an inlet funnel into the forming unit, where it is compressed transversely, wrapped in paper, and cut to the final length of the filter element. The additive applied to bond the filaments is usually a high-boiling solvent for cellulose acetate, such as glycerol triacetate (triacetin), for example, which solubilises the filament surface very quickly after application. Each time two filaments touch, a permanent bonding point is formed some time later, as the excess additive migrates to the fibre surface, whereby the previously liquid droplets of 2.5-dimethylcellulose acetate solidify in the additive. Due to the aforementioned migration of the hardener, after a storage period of less than one hour, mechanically interlocked three-dimensional filter rods are obtained. 2154744 of 21 strong, low-density packing materials which, due to their hardness, can be easily processed at high speed in modern cigarette machines. The selection of a relatively low filament titer, a relatively low total titer and an acetate weight of less than or equal to 2.5 mg per mm of length of the filter element for the fiber material of the filter element according to the invention makes it possible to realize a filter element which achieves the desired filtration performance in terms of condensable components and which, however, has sufficient filter hardness while maintaining the low total titer. According to embodiments of the inventive filter element, the cellulose acetate filaments of the monofilaments of the fiber material are at least partially formed as hollow and / or tubular cellulose acetate filaments. Particularly hollow / tubular cellulose acetate filaments are to be understood as preferably cylindrical filaments which show one or more continuous cavities when viewed in cross section. Such hollow fibers can be partially designed as multilumen hollow fibers. Compared to "solid" cellulose acetate filaments, single-lumen or multilumen tubular cellulose acetate filaments are considerably more resistant to bending, allowing the particularly high Filtrona hardness to be achieved without increasing material compression. Because the inventive filter element comprises a filter body capable of being based at least in part on cellulose acetate filaments which are at least partially formed as hollow cellulose acetate filaments, a low suction resistance and a low filtration efficiency can be obtained, since the filaments of the filter element formed at least partially as hollow cellulose acetate filaments have a small external surface area in relation to the total volume of the fiber. 2154744 of 21 In this context, it was surprisingly discovered that due to the filaments being partially formed as hollow cellulose acetate filaments, particularly high Filtrona hardnesses can be achieved with the filter element. In fact, it became evident that filter elements that are formed, at least partially, by hollow cellulose acetate filaments (hollow fibers) achieve the desired minimum Filtrona hardness with a lower fiber weight per unit volume. Since the inventive filter element is made of cellulose acetate filaments, the inventive filter element is designed to form a uniform, white, smooth mouth-side end face for a tobacco wick of, for example, a cigarette, by which a selective phenol filtration effect can also be realized. The use of a filter element based on cellulose acetate filaments allows, on the one hand, the production of filter rods specifically for cigarettes, which, from the point of view of smoking and health, have shown to have demonstrably exceptional properties in relation to specific retention phenomena. A filter made of cellulose acetate filters out harmful nitrosamines and phenols much more effectively than condensate and nicotine. Furthermore, smokers find the taste of currently common tobacco blends, such as American Blend, German Blend, and Virginia, combined with a filter made of cellulose acetate to be the most palatable. Another advantage of the cellulose acetate filter that should not be overlooked is the visual uniformity of the filter's cut surfaces. Since the inventive filter element is formed at least partially from hollow cellulose acetate filaments serving as filler material according to embodiments, there can be a wide range of varying suction resistance and filtration performance in filter rods made from the inventive material. 2154744 of 21 In particular, it has been shown that a filter material consisting at least partially of hollow cellulose acetate filaments exhibits a thermal cooling effect. It was determined that the use of hollow cellulose acetate filaments as a packing material was still capable of achieving a very low filtering effect—i.e., a retention effect—for suspended substances and gases to be removed. This effect is supposedly achieved because the hollow cellulose acetate filaments modify the surface or flow rate of the gas or air to be cleaned, resulting in only marginal retention of any potentially suspended matter in the gas / air. Another reason could be that the use of hollow cellulose acetate filaments can achieve a different, and particularly advantageous, surface structure of the filter material. The inventive filter element further has the advantage of allowing, in particular, variable cooling of a heated particle-laden gas (particularly aerosol), such that the temperature of the gas, aerosol, or vapor ingested by the consumer of a smoking product or HNB product can be selectively reduced. By varying the proportion of hollow cellulose acetate filaments in the filter and / or filler material, the desired cooling effect can be specifically tailored to the application. Furthermore, it is important to note that in the inventive filter element, the flow is essentially around and less so through the hollow cellulose acetate filaments (=hollow fibers). From geometrical considerations, it is obvious that the distances between fibers are considerably greater than the lumen (hollow section) of the hollow fiber. The viscosity of the aerosol (substantially air) then causes it to take the path of least resistance (i.e., flow between the filaments and not through each individual filament). In other words, the operational filtration surface is not maximized at all in the embodiment of the inventive filter element, since there is no continuous flow of the hollow cellulose acetate filaments in the fiber material. 2154744 of 21 In particular, the hollow cellulose acetate filaments may have bends that close the lumen of the hollow cellulose acetate filaments without affecting the performance of the inventive filter and / or the filling material with respect to the stated target parameters. In this context, it should be especially noted that hollow cellulose acetate filaments designed as hollow fibers do not necessarily have to be continuously hollow, but may also be partially closed by bends. It is also possible that they deviate from an ideal circular shape. Embodiments of the invention provide that the hollow cellulose acetate filaments of the fiber material serve, on the one hand, as a support material and, on the other, as a cooling material. Because the hollow cellulose acetate filaments simultaneously serve as a support material, particularly compact filter elements can be produced, which therefore do not require increasing the dimensions of the smoking product. The term “Filterna hardness,” as used herein, refers to the filter hardness determined according to the Filtrona principle. Under this principle, filter hardness is determined by vertically pressing the flat front end of a 12 mm diameter cylindrical rod onto a horizontally positioned filter under a 300 g load. The ratio of the compressed diameter to the initial diameter previously determined at the first contact results in the Filtrona hardness percentage. The hardness of the filter element, or filter rod, respectively, is an important objective criterion, particularly for cigarette filters. This is usually indicated as the so-called Filtrona hardness. It should be noted in this document that Filtrona hardness is only measured on a filter element, but not on the underlying (raw) filter material, i.e., the fiber material. The Filtrona hardness of a filter element is particularly influenced by the amount of triacetin that is or can be sprayed onto the filter element. 2154744 of 21 The minimum Filtrona hardness limit is approximately 88% and is geared toward market requirements. Thus, the Filtrona hardness of the filter element can preferably be set between approximately 88% and 95%, particularly approximately 90% to 93%. Preferred embodiments of the inventive filter element provide that the filter body is realized in particular as a filter and preferably with a diameter of between about 6 mm and about 4 mm and particularly a diameter of between about 5.5 mm and about 5.0 mm and preferably a diameter of about 5.35 mm, where at least part of the filter body is wrapped in a paper or a paper-like material. The Filtrona hardness of the filter element should preferably be greater than 85% in this embodiment and, in particular, greater than 90%. The Filtrona hardness is governed in particular by the weight of acetate for a given filter element diameter, whereby the cellulose acetate filament titer of the fiber material only has a minor influence on the Filtrona hardness. The inventive filter element configurations provide that the filter body has an acetate weight that achieves a maximum filter element length of 2.5 mg / mm. The Filtrona hardness of the filter element can also be achieved by using stronger filter wrapping paper or stronger tipping paper. Tipping paper is a paper that is either joined together by coupling several filter elements together, or a filter element is attached to a tobacco wick. However, increasing the Filtrona hardness of the filter element by using stronger filter wrapping paper or stronger tipping paper has economic disadvantages, as higher costs can be expected with this approach. Associated with the Filtrona hardness of the filter element is the so-called “hot collapse”, in which the hardness of the filter decreases as the element is used. 2154744 of 21 filter element; that is, the filter element used with smoky products or HNB products. This phenomenon can occur particularly with a traditional cigarette when the filter element heats up in the presence of moisture during one of the last puffs, although this undesirable effect can also occur with HNB products. In this context, it has been shown that the degree of reduction of Filtrona hardness due to the “hot collapse” phenomenon can be significantly reduced when a fiber material having the mentioned low filament titer, the mentioned low total titer and the low acetate weight is used as a base material of the inventive filter element. The fiber material of the filter body of the inventive filter element preferably has a specific surface area relative to the mass in the range between 0.3 m / g and 0.025 m / g, and in particular less than 0.15 m / g. In this way, the suction resistance and the filtration efficiency of the inventive filter element can be reduced without reducing the length of the filter element. In this way, relatively long filter elements can be realized which allow a correspondingly long cooling section, which is advantageous with respect to the thermal balance, particularly when the filter element is used with HNB products. Furthermore, the inventive specification of the specific surface area relative to the mass of the fiber material to a value particularly lower than 0.15 m2 / g makes it possible to reduce the suction resistance and the filtration efficiency of the filter element without reducing the weight of the fiber in the filter element per volume fraction and / or without reducing the total titer of the fiber material. This has the advantage that there is no decrease in the Filtrona hardness of the filter element due to a reduction in the weight of the fiber in the filter element material per volume fraction and / or due to a reduction in the total titer. The cellulose acetate filaments of the fiber material serving as the base product for producing the inventive filter element are in particular 16 2154744 of 21 filaments of 2.5 cellulose acetate, cellulose butyrate, cellulose acetate butyrate, cellulose acetate propionate and / or cellulose propionate. The cellulose acetate filaments preferably have a degree of substitution of about 1.5 to 3.0, preferably about 2.2 to 2.6. For example, the plasticizers preferably used for plasticizing the cellulose acetate fibers and applied to the fibers can be selected from the following groups: glycerol ester (particularly glycerol triacetate), ethylene and propylene carbonate, citric acid ester (particularly acetyl citrate, triethyl citrate), glycose ester or diethylene glycol dibenzoate. The person skilled in the art in this field of the technique knows the amount of water-soluble plasticizer and / or binding agent to be used.Generally, the plasticizer and / or bonding agent content is approximately 1% to 14% by weight; in special cases, however, the plasticizer content can easily exceed this range. The water-soluble binding agents, preferably present on the surface of the cellulose acetate filaments, may in particular be high-boiling solvents applied to the monofilaments of the fiber material or to the fiber material, such as polyalkylene oxides, water-soluble esters or ethers, starches, starch derivatives, p-polyvinyl alcohols, polyvinyl ethers, p-polyvinyl acetates and / or polysaccharides, water-soluble polyamides and polyacrylates. In the present case, it has been specifically recognized that the residual waviness (RS) of the fiber material of the filter body and the density (p) of the filter body also have a significant effect on the performance of the filter element. A density value related to the residual waviness A is therefore preferably at least 0.016 mg2 / mm6 with: A = p2· RS . The residual waviness (RS) of the fibre material of the filter body, in particular, must not exceed the value of 3.0 and, particularly, the value of 2.75, whereby the 2154744 of 21 residual curl (RS) of the fiber material is preferably between about 1.5 and about 2.75 and, in particular, between 1.9 and 2.5. Residual waviness refers to the ratio of the length of the crimped cellulose acetate filaments to the length of the filter element. Residual waviness is a characteristic of a given filter element. Surprisingly, it was found in this paper that a relatively low total titer of the filter body fiber material with an unchanged acetate weight requires a higher residual waviness titer to maintain the necessary filter hardness. Another aspect of the present invention relates to the specification of a fiber material for producing a filter element for filter mouthpieces used with smoking products or HNB products, wherein the fiber material is optimized so that filter elements produced from the fiber material exhibit the most consistent performance possible, in particular in terms of filtration efficiency and filter hardness. In this context, it was determined that it is also particularly important that the cellulose acetate filaments of the fiber material have a uniform filament count, which is, in particular, predefined or definable. This uniform, predefined or definable filament count falls within a range of 5 deniers to 10 deniers. In order to achieve consistent performance of the filter element made from the fiber material, particularly with respect to filtration efficiency and filter hardness, a coefficient of variation of the uniform filament titer should be at most 0.1 and preferably at most 0.05 to at most 0.01. The coefficient of variation of the uniform filament titer, which can also be called the coefficient of deviation, is a statistical parameter and characterizes, unlike the variance, a relative measure of dispersion; it is 2154744 of 21 that is, it does not depend on the unit of measurement of the statistical variable or the random variables. In other words, during the production of the fiber material, it is ensured that the individual filaments produced by the respective spinning machine dies used have a uniform filament count. Thus, this can be achieved in practice by assigning each spinneret its own spinning pump, in particular with controlled frequency, to ensure that each spinneret of the spinning machine receives the spinning fluid (approximately 30% solution of 2.5 cellulose acetate in acetone) in such a way as to achieve a uniform nozzle pressure and a uniform amount of spinning fluid supplied by each spinneret per unit of time. This easy-to-perform yet effective approach makes it possible to obtain a uniform filament titer, which in particular is predefined or definable. Alternatively or additionally, it is preferred that the monofilaments of the fiber material formed from the cellulose acetate filaments have a uniform total titer, which is in particular predefined or definable, of at least 5000 deniers and at most 10,000 deniers, where a coefficient of variation of the uniform total titer herein is preferably at most 0.1 and in particular at most 0.05 to at most 0.005. The coefficient of variation is therefore determined in particular by numerous measurements over the fiber length. This easily implemented measure can effectively prevent quality fluctuations during the manufacturing of the inventive filter element, which is unacceptable especially in the market for fine and ultra-fine filters and which would therefore lead to productivity losses during the manufacturing of the filter elements. Therefore, the advantages associated with the invention are numerous. In particular, it is possible to produce fine and ultra-fine filter elements, where the occurrence of the hot collapse phenomenon is effectively prevented even 2154744 of 21 when the fiber material of the filter body has a relatively low total value and a relatively low filament titer. 2154744 of 21 CLARKE MODET & CO. (ARGENTINA) SA - 30540437455 Digitally signed by PORTALTRAMITES - INPI Date: 2023.02.08 10:06:36 -03:00 Reason: Digitally signed by the INPI Location: Buenos Aires, Argentina 2154744

Claims

1. A filter element for filter mouthpieces for use with smoking products or HNB products, characterized in that the filter element has a filter body made of a fiber material, whereby the fiber material is formed by a plurality of intertwined and wavy cellulose acetate filament monofilaments, whereby the cellulose acetate filaments in particular have a multilobular or polygonal cross-sectional geometry and preferably Y-shaped, where: - the cellulose acetate filaments of the fiber material have a uniform filament count, which in particular is predefined or definable, in a range comprising less than or equal to 10 deniers (11.1 dtex) and more than or equal to 5 deniers (5.5 dtex); - the fiber material has a total count in a range comprising less than or equal to 10.000 deniers (11.1 kdtex) and greater than or equal to 5000 deniers (5555.5 dtex); and - the specific gravity of the cellulose acetate filaments of the fiber material is less than or equal to 2.5 mg per mm of filter element length and greater than or equal to 1.0 mg per mm of filter element length. 15 Claims follow.