Filter element for mouthpieces, mouthpiece for use in smoking products or hnb products, and cigarette filter

Abstract

The invention relates to a filter element for mouthpieces for use with smoking products or HNB products, the filter element having a filter body made of a tow material, the tow material being formed by a plurality of individual threads of cross-linked and crimped cellulose acetate filaments, the cellulose acetate filaments having in particular a multilobal or polygonal and preferably Y-shaped cross-sectional geometry. According to the invention: the cellulose acetate filaments of the tow material have a uniform filament titre, which is in particular predetermined or predefinable, in a range of less than or equal to 10 denier (11.1 dtex) and greater than or equal to 5 denier (5.5 dtex); the tow material has a total titre in a range of less than or equal to 10,000 denier (11.1 kdtex) and greater than or equal to 5,000 denier (5,555.5 dtex); and the specific fibre weight of the cellulose acetate filaments of the tow 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

[0001] FILTER ELEMENT FOR MOUTHPIECES, MOUTHPIECE FOR USE WITH SMOKING MATERIALS OR HNB PRODUCTS AND CIGARETTE FILTERS

[0002] Description

[0003] The invention relates to a filter element for mouthpieces for use with smoking articles or HNB products and to the use of such a filter element in mouthpieces for smoking articles or in cigarette filters or in mouthpieces for HNB products.

[0004] Smoking products within the meaning of the present invention relate to classic tobacco products, in particular cigarettes, but also pipes and marijuana products as well as so-called Heat-Not-Burn (HNB) products, vaping products and so-called hybrid products.

[0005] Depending on the application, mouthpieces for smoking products have different functions. On the one hand, mouthpieces can serve as a filter device, for example, to extract harmful components from a stream of tobacco smoke, such as condensed substances, especially tar, as well as particulate matter entrained by the smoke stream. This filter function is particularly used in traditional tobacco applications. A corresponding mouthpiece can be designed as an integral part of a cigarette or cigarillo, thus forming a "support" on the cigarette or cigarillo. Another type of mouthpiece is replaceable devices, such as replaceable filter elements, which can be removed after use. Such mouthpieces are housed in appropriate holders, for example, in a cigarette holder or a pipe mouthpiece.

[0006] The cigarette filter is a mouthpiece that forms an integral part of a cigarette. The cigarette filter is designed to reduce the amount of harmful substances, such as condensate and gas, in the cigarette smoke. Furthermore, a large percentage of smokers perceive the smoke as milder or more pleasant thanks to the filter. In a classic filter cigarette, the filter is wrapped in a filter wrapping paper and attached to the tobacco rod with a tipping paper. Most industrially manufactured cigarettes are equipped with a filter.

[0007] Numerous types of filter materials are already in use, primarily to reduce the content of tobacco smoke constituents before they reach the smoker's respiratory system. In addition to removing large quantities of harmful components, a satisfactory filter must also be effective without unduly obstructing the passage of air or smoke through the filter, necessitating excessively strong drafts. When using tobacco smoke filters, the filter material must also not alter the taste of the tobacco smoke by imparting its own flavor.

[0008] The present invention relates not only to filter materials for the classic tobacco applications described above, but in particular also to filter materials or filter elements for mouthpieces for use in smoking articles, wherein these filter elements in particular have functions other than merely a filtering function.

[0009] The materials required to form a mouthpiece for smoking products must therefore be adapted to the physical properties of the smoke (temperature, flow profile, etc.) and its chemical composition, and especially adaptable. In particular, both conventional cigarette filters and HNB products have a number of target parameters that must be adjusted or met through a suitable selection and configuration of the mouthpiece materials. These include, in particular, the following target parameters, which are briefly discussed below:

[0010] • Tensile resistance

[0011] • Filtration performance

[0012] • Filter rod hardness / Filtrona hardness

[0013] • Optics

[0014] Filter rod hardness is an important target criterion for cigarette filters. It is usually specified as the so-called Filtrona hardness. Filtrona hardness is determined by pressing a 12 mm diameter cylindrical rod with its flat end vertically onto a horizontally positioned filter rod with a load of 300 g. The ratio of the compressed diameter to the initial diameter previously determined by the first contact yields the percentage of Filtrona hardness.

[0015] It should be emphasized that Filtrona hardness is only measured on a filter, not on the underlying filter (raw) material. In particular, the triacetin sprayed on all cigarette filters influences Filtrona hardness.

[0016] The minimum Filtrona hardness limit is approximately 88% and is based on market requirements. The Filtrona hardness of the cigarette filter can preferably be set to approximately 88% to 95%, in particular approximately 90% to 93%.

[0017] For conventional cigarette filters, the Filtrona hardness is essentially determined by the fiber weight per unit volume for a given filter diameter. In particular, the filament titer has only a minor influence on the Filtrona hardness.

[0018] Occasionally, a higher Filtrona hardness is also achieved by using a thicker filter wrapping paper or a thicker tipping paper. A tipping paper is a paper used to either couple several filter elements together or to couple filter elements to the tobacco rod. However, increasing Filtrona hardness by using a thicker filter wrapping paper or a thicker tipping paper has economic disadvantages, as this approach is expected to incur higher costs. Related to Filtrona hardness is the so-called "hot collapse," in which the filter hardness decreases during smoking. This can occur particularly when the filter of a traditional cigarette is heated in the presence of moisture during one of the last puffs. This undesirable effect can also occur with HNB products.

[0019] In addition to maintaining the highest possible Filtrona hardness throughout the use of a smoking product, the mouthpiece material should also exhibit a predetermined or definable filtration performance. Filtration performance with respect to condensed matter (droplets, particles), also known as condensate or tar, is of interest for conventional tobacco products and HNB products, as condensed matter contains a variety of substances with negative health implications.

[0020] For conventional products, filtration performance (along with other influencing factors such as tobacco blend, ventilation, etc.) is selected to adjust the cigarette's "delivery" (the content of smoke constituents in the mainstream smoke). In many markets, "delivery" is capped by law. Below the legal limit, "delivery" can be adjusted to consumer preferences.

[0021] HNB products contain much less condensed matter with negative health implications in the aerosol than conventional products. However, since more desirable substances, such as flavorings and nicotine, are also present in the condensate, the goal here is to choose the lowest possible filtration performance, but not to allow it to drop to zero.

[0022] With regard to the target parameter "draw resistance," it should be noted that consumers prefer a certain draw resistance range when consuming a tobacco product. In conventional cigarettes, the filter (in addition to the "delivery" setting) serves to adjust the draw resistance of the cigarette.

[0023] However, in HBN products, the draw resistance contribution of the mouth-side filter (mouthpiece) should generally be as low as possible, since the other components of the HBN device, especially the heated tobacco portion and the device, already contribute a high amount of draw resistance. A low draw resistance of the filter (mouthpiece) leads to degrees of freedom for the other components of the HBN device, which is desirable.

[0024] However, draw resistance and filtration performance are closely linked. Both can be reduced in several ways, but this often negatively impacts other parameters.

[0025] For example, draw resistance and filtration performance can be reduced by reducing the filter length. However, as soon as the filter length becomes smaller than the filter diameter, processability becomes problematic. A shorter filter also results in a shorter cooling path, which is problematic for heat management.

[0026] Alternatively or additionally, the draw resistance and filtration performance can be reduced by reducing the fiber weight in the filter material per volume fraction and / or the total titer. However, this has the disadvantage that the Filtrona hardness decreases, and in some cases, the minimum hardness may no longer be achieved.

[0027] Alternatively or additionally, the draw resistance and filtration performance can be reduced by increasing the filament titer. For a constant filter diameter and a given fiber weight per unit volume, increasing the filament titer reduces the filtration performance and draw resistance, which is desirable for HNB products compared to conventional products. Since, as explained above, Filtrona hardness is hardly dependent on the filament titer, the hardness is not negatively affected either.

[0028] With regard to the target parameter "appearance," it should be noted that consumers prefer a mouthpiece with a flat, white cross-sectional area at the mouth. However, there are also products that are shaped into a tube at the mouth.

[0029] Although conventional cigarette filters, usually made of cellulose acetate filaments, ensure optimal filtration of smoke constituents, these filter materials are often only of limited use in other applications, particularly with HNB products or e-cigarettes, because in these applications, the filter materials or mouthpiece materials must perform other functions. HNB products, as well as conventional smoking accessories, generally have the disadvantage that the inhaled aerosol is absorbed by the user at a high temperature. This can be unpleasant for the user. Especially with HNB products, the mouthpiece materials therefore have the task of cooling the aerosol while maintaining the lowest possible filtration performance.

[0030] But even with classic cigarettes, especially so-called slim or ultra-slim cigarettes, i.e. cigarettes with a small diameter of, for example, 5.0 mm to 6.5 mm, filter materials or mouthpiece materials must offer reduced filtration performance and increased cooling and improved haptic properties (firm, but not too hard grip) compared to filter materials for king-size cigarettes. Naturally, less smoke / flavor is produced during combustion than with a king-size cigarette. To avoid further reducing the flavor, a low filtration performance is aimed for. If only the amount of filter material is reduced for this purpose, the filter hardness will eventually become insufficient.

[0031] Filters for slim or ultra-slim cigarettes also have significantly higher draw resistance than king-size filters with the same fiber density, which is generally undesirable.

[0032] For both HNB products and slim or ultra-slim cigarettes, it has been proposed to achieve the desired reduced filtration performance with respect to condensable components, such as tar, as well as sufficient filter hardness by increasing the filament titer while maintaining the overall titer. However, this approach has several disadvantages.

[0033] Cellulose 2,5-acetate is widely used today to manufacture filter rods for filter elements and cigarette filters. In light of the debate on smoking and health, it has proven to possess outstanding properties regarding specific retention phenomena. For example, a filter made of cellulose acetate filters harmful nitrosamines and phenols far more effectively than condensate and nicotine. Furthermore, smokers consider the smoky taste of the tobacco blend to be most pleasant when combined with a cellulose acetate filter element. Another not to be underestimated advantage of a cellulose 2,5-acetate filter element is the optical homogeneity of the filter's cut surfaces.

[0034] However, despite their undeniable market dominance, filter elements made of cellulose 2,5-acetate have some serious disadvantages: tensile resistance and filtration performance are clearly defined for filter rods due to structural physical specifications.

[0035] The particle filtration or condensate retention of a conventional filter element made of cellulose 2,5-acetate is a function of filament titer (fiber fineness), filter diameter, draw resistance and filter length.

[0036] The production of filter elements becomes problematic when a filter performance of significantly more than 50% is required, as is necessary for the design of ultra-light cigarettes, with a typical filter diameter of 7.8 mm and a filter length of 21 to 25 mm.

[0037] The same applies, in a figurative sense, to filter elements for slim or ultra-slim cigarettes. Since the smoke flows parallel to the fiber direction in a filter element, such a filter element can only be achieved by significantly reducing the filament titer, which would result in a significant increase in draw resistance while maintaining the overall titer.

[0038] The total titer and filament titer must therefore be reduced equally, resulting in a drastic reduction in the hardness of the filter element, especially during the fume extraction process. This phenomenon is referred to by experts as "hot collapse" and is considered fundamentally undesirable.

[0039] The present invention is based on the object of providing a filter element, particularly for so-called slim or ultra-slim cigarettes, i.e., cigarettes with a small diameter of, for example, 5.0 mm to 6.5 mm, wherein the filter element has sufficient filter hardness despite reduced filtration performance and increased cooling. Furthermore, the filter element should be capable of achieving an adjustable draw resistance that is reduced, in particular compared to king-size filters. This object is achieved according to the invention by a filter element having the features of independent patent claim 1, wherein advantageous developments of the filter element according to the invention are specified in the dependent claims.

[0040] Accordingly, the invention particularly relates to a filter element for mouthpieces for use with tobacco products or HNB products, wherein the filter element comprises a filter body made of a tow material. The tow material is formed by a plurality of individual threads of cross-linked and crimped cellulose acetate filaments, wherein the cellulose acetate filaments in particular have a multilobal or polygonal and preferably Y-shaped cross-sectional geometry.

[0041] The filter element according to the invention is characterized in particular by the fact that a specific filament titer is selected for the cellulose acetate filaments of the tow material. The filament titer is preferably in a range of less than or equal to 10 denier and greater than or equal to 5 denier.

[0042] In addition, a relatively low total titer is selected for the tow material of the filter element according to the invention, preferably a total titer in a range of less than or equal to 10,000 denier and greater than or equal to 5,000 denier.

[0043] It was surprisingly found that, despite the comparatively low filament titer of less than or equal to 10 denier and the relatively low total titer of less than or equal to 10,000 denier, the occurrence of the completely undesirable hot collapse phenomenon can be effectively avoided even when used in slim or ultra-slim cigarettes if a comparatively low value of less than or equal to 2.5 mg per mm of filter element length is selected for the specific fiber weight of the cellulose filaments of the tow material, ie for the so-called acetate weight.

[0044] With the specifications regarding the relatively low filament titer, the relatively low total titer, and the relatively low specific fiber weight of the cellulose acetate filaments (acetate weight), a filter element can be realized that meets the filter performance required for the construction of slim or ultra-slim cigarettes without a significant increase in draw resistance. These parameters can significantly increase the achievable performance of the filter element and the range of applications.

[0045] In particular, the cellulose acetate filaments of the tow material have, at least in part, a trilobal cross-sectional shape, i.e., a three-armed star-shaped cross-section. This cross-sectional shape is suitable when the cellulose acetate filaments are to have the largest possible specific surface area, enabling high filtration capacity while simultaneously using raw materials economically—if desired, as is the case with traditional cigarettes, for example.

[0046] Alternatively, it is possible to achieve a desired large specific surface area by bundling extremely fine filaments, for example, with a circular cross-section. However, other cross-sectional shapes for the cellulose acetate filaments are also conceivable, such as multilobal, polygonal, or X-shaped cross-sections.

[0047] The tow material of the filter element according to the invention is made of endless stuffer-box-crimped cellulose acetate filaments. A solution of approximately 30% cellulose 2,5-acetate in acetone is forced through spinnerets, the acetone is evaporated in a spinneret, a large number of cellulose acetate filaments (5,000 to 10,000) are gathered into a ribbon, and this ribbon is then stuffer-box-crimped.

[0048] The product is then dried, filled into storage containers and finally pressed into bales weighing 300 to 600 kg.

[0049] After the filter tow bales are transported to the filter or cigarette manufacturer, the filter tow is removed from the bale and processed into filter rods on a filter rod machine. The filter tow is stretched in a stretching device, treated with an additive to bond the filaments, and then, after forming a three-dimensional sliver, fed into the formatting section via an inlet funnel, where it is compacted transversely axially, wrapped in paper, and cut to the final length of the filter rods. The additive used to bond the filaments is usually a high-boiling solvent for cellulose acetate, such as glycerol triacetate (triacetin), which briefly dissolves the surface of the filaments after application.Wherever two filaments accidentally touch, a solid bond develops after some time, as the excess additive migrates into the fiber surface, causing the previously liquid solution droplet of cellulose 2,5-acetate to solidify within the additive. After a storage period of less than one hour, the aforementioned migration of the curing agent results in mechanically strong, three-dimensionally cross-linked filter rods with a low packing density. Due to their hardness, these rods can be easily processed at high speeds on modern cigarette machines.

[0050] By selecting a relatively low filament titre, a relatively low total titre and an acetate weight of less than or equal to 2.5 mg per mm of filter element length for the tow material of the filter element according to the invention, a filter element can be realized which achieves a desired filtration performance with respect to condensable components but nevertheless a sufficient filter hardness while maintaining the low total titre.

[0051] According to embodiments of the filter element according to the invention, the cellulose acetate filaments of the individual threads of the tow material are formed at least in regions as hollow and / or tubular cellulose acetate filaments.

[0052] Hollow or tubular cellulose acetate filaments are to be understood as meaning, in particular, preferably cylindrical filaments which, viewed in cross-section, have one or more continuous cavities.

[0053] Such hollow fibers can be designed, at least partially, as multi-lumen hollow fibers. Compared to "solid" cellulose acetate filaments, single- or multi-lumen tubular cellulose acetate filaments are significantly more kink-resistant, allowing particularly high Filtrona hardnesses to be achieved without increased material densification.

[0054] Because the filter element according to the invention has a filter body which can be based at least partially on cellulose acetate filaments which are at least partially formed as hollow cellulose acetate filaments, a low tensile resistance and a low filtration performance can be realized, since the filaments of the filter element which are at least partially formed as hollow cellulose acetate filaments have a small outer surface relative to the total fiber volume.

[0055] In this context, it was surprisingly found that, due to the filaments being at least partially formed as hollow cellulose acetate filaments, particularly high Fi Itrona hardnesses can be achieved with the filter element.

[0056] In fact, it has been found that filter elements that are at least partially formed from hollow cellulose acetate filaments (hollow fibers) achieve the desired minimum Filtrona hardness with a lower fiber weight per unit volume.

[0057] Since the filter element according to the invention is based on cellulose acetate filaments, the filter element according to the invention is designed to form a uniform, white and flat mouth-side end face for a tobacco rod, for example a cigarette, wherein a selective filtration effect on phenols can also be realized.

[0058] By using a filter element based on cellulose acetate filaments, filter rods can be produced, particularly for cigarettes, which, with regard to the discussion on smoking and health, have proven to have outstanding properties regarding specific retention phenomena.

[0059] For example, a cellulose acetate filter filters harmful nitrosamines and phenols far more effectively than condensate and nicotine. Furthermore, smokers find the smoky taste of today's common tobacco blends, such as "American Blend," "German Blend," and "Virginia," most pleasant when combined with a cellulose acetate filter rod. Another not to be underestimated advantage of a cellulose acetate filter rod is the optical homogeneity of the filter's cut surfaces.

[0060] Since, according to embodiments, the filter element according to the invention is formed at least partially from hollow cellulose acetate filaments which serve as filling material, the tensile resistance and the filtration performance of filter rods made from the material according to the invention can be varied over a wide range.

[0061] In particular, it has been shown that a filter material consisting, at least in part, of hollow cellulose acetate filaments exhibits an improved thermal cooling effect. It was found that the use of hollow cellulose acetate filaments as filler material still allows a very low filtering efficiency, i.e., retention efficiency, for the suspended particles and gases to be removed.

[0062] It is assumed that this effect is achieved by the hollow cellulose acetate filaments altering the surface or flow rate of the gas or air to be purified in such a way that any suspended particles present in the gas or air are barely retained. Another reason could be that the use of hollow cellulose acetate filaments allows for a different, particularly advantageous surface structure of the filter material.

[0063] The filter element according to the invention further has the advantage of enabling adjustable cooling of a heated, particle-laden gas (especially an aerosol), so that the temperature of the gas, aerosol, or vapor inhaled by the user of a smoking article or HNB product can be specifically reduced. By varying the proportion of hollow cellulose acetate filaments in the filter and / or filler material, the desired cooling effect can be adapted to the specific application.

[0064] It is also important to note that the hollow cellulose acetate filaments (= hollow fibers) in the filter element according to the invention are essentially flowed around rather than through. Geometric considerations show that the fiber-to-fiber distances are significantly larger than the lumen (hollow portion) of the hollow fiber. The viscosity of the aerosol (essentially air) then ensures that the path of least resistance is chosen (i.e., it flows between the filaments rather than through each individual filament).

[0065] In other words, in the embodiment of the filter element according to the invention, the filtration-effective surface is by no means maximized, since the hollow cellulose acetate filaments in the tow material are not flowed through.

[0066] In particular, the hollow cellulose acetate filaments can thus have kinks that close the lumen of the hollow cellulose acetate filaments without this having an influence on the performance of the filter and / or filling material according to the invention with regard to the set target parameters.

[0067] It's particularly worth mentioning in this context that the hollow-fiber cellulose acetate filaments don't necessarily have to be completely hollow, but can also be partially closed by kinks. They can also deviate from an ideal circular shape.

[0068] In embodiments of the invention, the hollow cellulose acetate filaments of the tow material serve both as a carrier material and as a cooling material. By simultaneously serving as a carrier material, the hollow cellulose acetate filaments allow for particularly compact filter elements that do not require an increase in the dimensions of the smoking article.

[0069] The term "Fi Itrona hardness" used herein refers to the filter hardness determined according to the Filtrona principle. According to this principle, the filter hardness is determined by pressing a cylindrical rod of 12 mm diameter with its flat end vertically onto a horizontally positioned filter rod with a load of 300 g. The ratio of the compressed diameter to the initial diameter previously determined by the first contact yields the percentage indication of the Filtrona hardness.

[0070] The hardness of the filter element or filter rod is an important target criterion, especially for cigarette filters. It is usually specified as the so-called Filtrona hardness. It should be noted that the Filtrona hardness is only measured on a filter element, not on the underlying filter (raw) material, i.e., the tow material. The Filtrona hardness of a filter element is influenced in particular by the amount of triacetin that is / can be sprayed onto the filter element. The minimum limit for Filtrona hardness is approximately 88% and is based on market requirements. The Filtrona hardness of the filter element can preferably be set to approximately 88% to 95%, in particular approximately 90% to 93%.

[0071] According to preferred embodiments of the filter element according to the invention, it is provided that the filter body is designed in particular as a filter rod and preferably has a diameter between approximately 6 mm and approximately 4 mm and in particular a diameter between approximately 5.5 mm and approximately 5.0 mm and preferably a diameter of approximately 5.35 mm, wherein the filter body is at least partially covered with a paper material or a paper-like material.

[0072] In this design, the Filtrona hardness of the filter element should preferably be greater than 85% and in particular greater than 90%.

[0073] For a given filter element diameter, the Filtrona hardness is determined in particular by the acetate weight, whereby the filament titer of the cellulose acetate filaments of the tow material has only a minor influence on the Filtrona hardness.

[0074] In embodiments of the filter element according to the invention, it is provided that the filter body has an acetate weight which is a maximum of 2.5 mg / mm filter element length.

[0075] The Filtrona hardness of the filter element can also be achieved by using a stronger filter wrapping paper or a stronger tipping paper.

[0076] Tipping paper is a paper used to either connect multiple filter elements together or to connect a filter element to a tobacco rod. However, increasing the Filtrona hardness of the filter element by using a thicker filter wrapping paper or a thicker tipping paper has economic disadvantages, as this approach is expected to result in higher costs.

[0077] Associated with the Filtrona hardness of the filter element is the so-called "hot collapse," whereby the filter hardness decreases during use of the filter element, i.e., during use of the filter element with tobacco products or HNB products. This phenomenon can occur particularly when, in a conventional cigarette, the filter element is heated in the presence of moisture during one of the last puffs. However, this undesirable effect can also occur with HNB products.

[0078] In this context, it has been shown that the degree of decrease in Filtrona hardness due to the "hot collapse" phenomenon can be significantly reduced if a tow material with the mentioned low filament titer, the mentioned low total titer and the low acetate weight is used as the starting material of the filter element according to the invention.

[0079] The tow material of the filter body of the filter element according to the invention preferably has a mass-related specific surface area in the range between 0.3 m 2 / g and 0.025 m 2 / g and in particular less than 0.15 m 2 / g. This allows the draw resistance and filtration performance of the filter element according to the invention to be reduced without reducing the length of the filter element. Thus, relatively long filter elements can be realized, allowing a correspondingly long cooling path, which is advantageous for heat management, especially when the filter element is used with HNB products.

[0080] In addition, by setting the mass-related specific surface area of ​​the tow material according to the invention to a value of in particular less than 0.15 m 2 / g, the draw resistance and filtration performance of the filter element can be reduced without reducing the fiber weight in the filter element per volume fraction and / or without reducing the total titer of the tow material. This has the advantage that there is no decrease in the Filtrona hardness of the filter element due to a reduction in the fiber weight in the filter element material per volume fraction and / or due to a reduction in the total titer.

[0081] The cellulose acetate filaments of the tow material serving as the starting material for producing the filter element according to the invention are, in particular, cellulose 2,5-acetate, cellulose butyrate, cellulose acetobutyrate, cellulose acetopropionate, and / or cellulose propionate filaments. The cellulose acetate filaments preferably have a degree of substitution of approximately 1.5 to 3.0, preferably approximately 2.2 to 2.6. The plasticizers preferably used to plasticize the cellulose acetate fibers and applied to the fibers can be selected, for example, from the following groups: glycerol esters (especially glycerol triacetate), ethylene and propylene carbonate, citric acid esters (especially acetyl and triethyl citrate), glucose esters, or diethylene glycol dibenzoate.

[0082] The amount of plasticizing plasticizer and / or water-soluble adhesive to be used is familiar to those skilled in this technical field. Generally, the plasticizer and / or adhesive content is approximately 1 to 14 percent by weight; however, in special cases, the plasticizer content can easily exceed this range.

[0083] As water-soluble adhesives, which are preferably present on the surface of the cellulose acetate filaments, there can be used in particular high-boiling solvents, such as polyalkylene oxide, water-soluble esters or ethers, starch, starch derivatives, P-polyvinyl alcohols, polyvinyl ethers, P-polyvinyl acetates and / or polysaccharides, water-soluble polyamides and polyacrylates, which are applied to the individual threads of the tow material or to the tow material.

[0084] In particular, it was recognized that the residual crimp (RS) of the tow material of the filter body and the density ( ) of the filter body also have a decisive influence on the performance of the filter element. Preferably, a residual crimp-related density value A is at least 0.016 mg 2 / mm 6 with:

[0085] A = p 2 - RS .

[0086] In particular, the residual crimp (RS) of the tow material of the filter body should not exceed 3.0 and especially 2.75, with the residual crimp (RS) of the tow material preferably being between approximately 1.5 and approximately 2.75, and especially between 1.9 and 2.5. The residual crimp is understood as the ratio of the length of the terminal crimp (rarely cellulose acetate) filaments to the filter element length. The residual crimp is a characteristic feature of a given filter element.

[0087] It was surprisingly found that with a relatively low total titer of the tow material of the filter body and a constant acetate weight, a higher residual crimp value is required to maintain the necessary filter hardness.

[0088] According to a further aspect of the present invention, it is important to provide a tow material for producing a filter element for mouthpieces for use with smoking articles or HNB products, wherein the tow material is optimized such that the filter elements produced from the tow material have the most uniform performance possible, in particular with regard to filtration performance and filter hardness.

[0089] In this context, it was determined that it is particularly important that the cellulose acetate filaments of the tow material have a uniform filament count, which can be predetermined or specified in advance. This uniform filament count, which can be predetermined or specified in advance, is preferably in a range between 5 and 10 denier.

[0090] In order to achieve a uniform performance of the filter element made of the tow material, especially with regard to filtration performance and filter hardness, a variation coefficient of the uniform filament titre should be a maximum of 0.1 and preferably a maximum of 0.05 to a maximum of 0.01.

[0091] The coefficient of variation of the uniform filament titer, which can also be called the deviation coefficient, is a statistical parameter and describes - in contrast to the variance - a relative measure of dispersion, ie it does not depend on the unit of measurement of the statistical variable or random variable.

[0092] In other words, during the production of the tow material, care is taken to ensure that the individual filaments produced by the respective spinnerets of the spinning machine in use have a uniform filament linear density. In practice, this is achieved by assigning each spinneret its own spinning pump, particularly a frequency-controlled one, to ensure that the spinning fluid (a solution of approximately 30% cellulose 2,5-acetate in acetone) is supplied to each spinneret of the spinning machine in such a way that a uniform nozzle pressure and a uniform amount of spinning fluid delivered per unit of time by each spinneret can be achieved.

[0093] With this simple to implement but nevertheless effective method, it is possible to realize a uniform filament titer, particularly one that is predetermined or can be determined in advance.

[0094] Alternatively or additionally, it is preferred that the individual threads of the tow material formed from the cellulose acetate filaments have a predetermined or determinable and preferably uniform total titer of at least 5,000 denier and a maximum of 10,000 denier, with a variation coefficient of the uniform total titer preferably being at most 0.1 and in particular at most 0.05 to a maximum of 0.005. The variation coefficient is determined in particular by multiple measurements along the length of the tow.

[0095] With this easy-to-implement measure, fluctuating qualities can be effectively avoided during the production of the filter element according to the invention, which is unacceptable in particular on the market for slim and ultra-slim filters and would therefore entail productivity losses during the production of the filter elements.

[0096] The advantages associated with the invention are thus manifold. In particular, the realization of slim and ultra-slim filter elements is possible, effectively preventing the occurrence of the hot collapse phenomenon, even when the tow material of the filter body has a relatively low total and filament densities.

Claims

Patent claims: Filter element for mouthpieces for use with smoking products or HNB products, wherein the filter element comprises a filter body made of a tow material, wherein the tow material is formed by a plurality of individual threads of cross-linked and crimped cellulose acetate filaments, wherein the cellulose acetate filaments in particular have a multilobal or polygonal and preferably Y-shaped cross-sectional geometry, wherein: the cellulose acetate filaments of the tow material have a uniform filament titer, in particular predetermined or definable, in a range of less than or equal to 10 denier (11.1 dtex) and greater than or equal to 5 denier (5.5 dtex); the tow material has a total titer in a range of less than or equal to 10,000 denier (11.1 kdtex) and greater than or equal to 5,000 denier (5.5 dtex).555.5 dtex); and the specific fiber weight of the cellulose acetate filaments of the Tow material is less than or equal to 2.5 mg per mm filter element length and greater than or equal to 1.0 mg per mm filter element length. Filter element according to claim 1, wherein the coefficient of variation of the uniform total titer is at most 0.1 and preferably at most 0.05 to at most 0.

005. Filter element according to claim 1 or 2, wherein the coefficient of variation of the uniform filament titer is at most 0.1 and preferably at most 0.05 to at most 0.

01. Filter element according to any one of claims 1 to 3, wherein the filter body is in particular designed as a filter rod and has a diameter between about 6 mm and about 4 mm and in particular a diameter between about 5.5 mm and about 5.0 mm and preferably a diameter of about 5.35 mm, wherein the filter body is at least partially encased with a paper material or a paper-like material.Filter element according to claim 4, wherein the filter body with the covering made of paper material or paper-like material has a compression depth of less than 0.90 mm and in particular less than 0.85 mm when a cylindrical test body with a mass of 300 g and a diameter of 12 mm is placed on the end face of the filter body perpendicular to the filter body axis. Filter element according to claim 4, wherein the filter body without the covering made of paper material or paper-like material has a compression depth of less than 0.90 mm and in particular less than 0.85 mm when a cylindrical test body with a mass of 300 g and a diameter of 12 mm is placed on the end face of the filter body perpendicular to the filter body axis.Filter element according to one of claims 1 to 6, wherein at least a part of the cellulose acetate filaments of the individual threads of the tow material is formed at least partially as hollow and / or tubular cellulose acetate filaments. Filter element according to any one of claims 1 to 7, wherein the hardness of the filter body is at least 80% Filtrona hardness and preferably at least about 86% Filtrona hardness. Filter element according to any one of claims 1 to 8, wherein the filter body comprises a plasticizer with a plasticizer content between about 2% and about 15% and preferably between about 4% and about 10%, wherein the plasticizer comprises in particular triacetin, triethylene glycol diacetate and / or ethyl citrate. Filter element according to any one of claims 1 to 9, wherein the tow material of the filter body has a residual crimp (RS) and a density ( ), wherein a residual crimp-related density value A is at least 0.016 mg 2 / mm 6 is, with: A = p 2 - RS filter element according to any one of claims 1 to 10, and in particular according to claim 10, wherein the residual crimp (RS) of the tow material of the filter body does not exceed a value of 3.0, and wherein the residual crimp (RS) of the tow material of the filter body is preferably between about 1.5 and about 2.75, and in particular between 1.9 and 2.

5. Filter element according to any one of claims 1 to 11, wherein the cellulose acetate filaments of the tow material have a tensile strength of at least 2.6 N / kden. Mouthpiece for use with tobacco products or HNB products, wherein the mouthpiece comprises a filter element according to any one of claims 1 to 12. Mouthpiece according to claim 13, wherein a flavor-delivering element, in particular a capsule-shaped or capsule-like element, is embedded in the filter element. Cigarette filter or cigarette filter element which comprises a filter element according to any one of claims 1 to 12.

16. Cigarette filter or cigarette filter element according to claim 15, wherein a flavor release element, in particular a capsule-shaped or capsule-like element, is embedded in the filter element.