Mouthpiece filter elements, mouthpieces for use in smoking products or HNB products, and cigarette filters

Abstract

To identify filter elements that exhibit sufficient filter hardness despite reduced filtering performance and increased cooling, especially for so-called slim or ultra-slim cigarettes. [Solution] A filter element for a mouthpiece for use in a smoking product or HNB product, the filter element having a filter body made of a tow material, the tow material being formed by a plurality of monofilaments of crosslinked and crimped cellulose acetate filaments, the cellulose acetate filaments exhibiting a cross-sectional shape, in particular a multilobal or polygonal, preferably Y-shaped, shape, in which: - the cellulose acetate filaments of the tow material exhibit a uniform filament titer, in particular a predefined or predefinable value, in the range of 10 denier (11.1 dtex) or less and 5 denier (5.5 dtex) or more; - the tow material has a total titer in the range of 10,000 denier (11.1 kdtex) or less and t5,000 denier (5555.5 dtex) or more; and - the specific fiber weight of the cellulose acetate filaments of the tow material is 2.5 mg or less per mm of filter element length and 1.0 mg or more per mm of filter element length.

Description

[Technical field]

[0001] The present invention relates to a tipping filter element for use with a smoking product or an HNB product, and to the use of such a filter element in a tipping for a smoking product or a cigarette filter or a tipping for an HNB product. [Background technology]

[0002] Smoking products within the meaning of the present invention relate to traditional tobacco products, in particular cigarettes, but also pipe products and marijuana products, as well as so-called heat-not-burn (HNB) products, vaping products and so-called hybrid products.

[0003] Depending on the application, the mouthpiece for using a smoking product has different functions. For example, the mouthpiece can function on the one hand as a filter device that extracts harmful components from the tobacco smoke stream, such as condensed matter, especially tar, as well as particulate matter entrained in the smoke stream. This filtering function is used in particular in conventional tobacco applications. The corresponding mouthpiece can thereby be formed as an integral part of the cigarette or cigarillo and thus form a "support" on the cigarette / cigarillo.

[0004] Another type of tipping example relates to replaceable devices, such as replaceable filter elements that can be removed after use. Such tips are housed in a suitable holder, for example a cigarette holder or a pipe tipping.

[0005] One tip formed as an integral part of the cigarette is the cigarette filter. The cigarette filter is intended to reduce the proportion of harmful substances such as condensate and gases in the cigarette smoke. In addition, the filter makes the smoke smoother or more palatable for the majority of smokers. In conventional filter cigarettes, the filter is surrounded by a filter wrap and connected to the tobacco rod via a so-called tipping paper, and most industrially manufactured cigarettes are equipped with a filter.

[0006] There are many types of filter materials already in use, especially to reduce substances in tobacco smoke before they reach the smoker's respiratory system. However, in addition to removing a large amount of harmful substances, a satisfactory filter must also be effective without undesirably impeding the passage of air or smoke through the filter, and thus without requiring excessive suction against the filter. However, when using tobacco smoke filters, the filter material must not change the taste of the tobacco smoke by adding its own flavor.

[0007] The present invention does not only relate to filter materials for traditional tobacco applications as described above, but also in particular to filter materials and / or filter elements for mouthpieces used in smoking products, these filter elements in particular having other functions than just a filtering function.

[0008] Therefore, the materials required to form the tipping for a smoking product must be adapted, and in particular must be adaptable, to the physical properties (temperature, flow profile, etc.) and chemical composition of smoke. Both conventional cigarette filters and HNB products in particular have several target parameters that must be adjusted or met, respectively, by the appropriate selection and configuration of the tipping material. This relates in particular to the following target parameters, which are briefly discussed below: ·Suction resistance Filtering performance Filter Rod Hardness / Filtrona Hardness Visual appearance

[0009] Filter rod hardness is an important target criterion for cigarette filters. It is usually indicated as the so-called Filtrona hardness. The Fitrona hardness is determined by pressing the flattened front end of a cylindrical rod with a diameter of 12 mm vertically against a horizontally placed filter rod with a load of 300 g. The ratio of the compressed diameter to the initial diameter previously determined at the first contact gives the Filtrona hardness percentage.

[0010] It should be emphasized that Filtrona hardness is measured only on the filter, and not on the parent (raw) filter material. Filtrona hardness is particularly affected by triacetin sprayed onto all cigarette filters.

[0011] The minimum limit of the Filtrona hardness is about 88%, which is set according to market requirements. Therefore, the Filtrona hardness of the cigarette filter can be preferably set to about 88% to 95%, particularly about 90% to 93%.

[0012] In conventional cigarette filters, Filtrona firmness is essentially determined by the fiber weight per unit volume for a given filter diameter. In particular, filament titer has only a small effect on Filtrona firmness.

[0013] Sometimes, a higher Filtrona hardness can be achieved by using stronger filter wrap paper or stronger tipping paper. Tipping paper is the paper that bonds multiple filter elements together or that bonds a filter element to a tobacco rod. However, increasing Filtrona hardness by using stronger filter wrap paper or stronger tipping paper has economic disadvantages, since higher costs can be expected with this approach.

[0014] Filtrona hardness is accompanied by a so-called "hot collapse" in which the filter hardness decreases during smoking. This can occur especially in conventional cigarettes when the filter is heated in the presence of moisture during one of the last puffs. This undesirable effect can also occur with HNB products.

[0015] In addition to a Filtrona hardness that is as constant and high as possible during use of the smoking product, the tipping material must also exhibit a given or definable filtering performance. The filtering performance with respect to condensed matter (droplets, particles), also called condensate or tar, is interesting for conventional tobacco products and HNB products, because condensed matter contains several substances that have unhealthy effects.

[0016] In conventional products, filtration performance (along with other influencing factors such as tobacco blend, breathability, etc.) is selected to adjust the "delivery" of the cigarette (the level of smoke constituents in the mainstream smoke). In many markets, legal regulations dictate an upper limit for "delivery". Below the legal limit, "delivery" can be tailored to consumer preferences.

[0017] In HNB products, the aerosol contains much less condensate with negative health effects than in conventional products, however, more desirable materials such as flavors and nicotine are also present in the condensate, so the objective here is to select the lowest possible filtering performance without reducing it to zero.

[0018] With respect to the target parameter of "resistance to draw", it is noteworthy that consumers prefer a certain range of resistance to draw when using a tobacco product. In a conventional cigarette, the filter (in addition to adjusting the "delivery") serves to adjust the resistance to draw of the cigarette.

[0019] However, in HNB products, the resistance to draw provided by the mouth filter (tip) should tend to be as low as possible, since other components of the HBN device, particularly the heated portion of the tobacco and the device, already provide a high contribution to the resistance to draw. A low filter (tip) resistance to draw allows some latitude with respect to other components of the HBN device, which is desirable.

[0020] However, resistance to draw and filtering performance are closely related: both can be reduced in several ways, often with a negative impact on other parameters.

[0021] For example, the resistance to draw and filtering performance can be reduced by shortening the length of the filter. However, when the filter length is smaller than the filter diameter, processability becomes an issue. A shorter filter also results in a shorter cooling section, which is an issue with respect to heat balance. Alternatively or additionally, the resistance to draw and filtering performance can be reduced by reducing the fiber weight in the filter material per volume content and / or total titer. However, this has the drawback of reducing the filtrona hardness, and the minimum hardness may no longer be achieved.

[0022] Alternatively or additionally, the resistance to suction and filtering performance can be reduced by increasing the filament titer. At a constant filter diameter and a fixed fiber weight per volume unit, the filtering performance and resistance to suction decrease with increasing filament titer, which is desirable for HNB products compared to conventional products. As mentioned above, Filtrona hardness is only slightly dependent on filament titer, so hardness is also not adversely affected.

[0023] Regarding the "visual appearance" target parameter, it is noteworthy that consumers prefer mouthpieces that have a flat, white cross-sectional area at the mouth end. However, some products are formed into a tube at the mouth end.

[0024] Although conventional cigarette filters, usually composed of cellulose acetate filaments, ensure optimal filtering of constituents in the smoke, these filter materials can often only be used to a limited extent in other applications, especially in the case of HNB products or electronic cigarettes, because in these applications the filter material or the respective tipping material must assume other functions.

[0025] HNB products and conventional smoking products generally have the disadvantage that the user ingests inhaled aerosol at a high temperature, which can be uncomfortable for the user. In particular, in HNB products, the mouthpiece material has the task of cooling the aerosol with the lowest possible filtering performance.

[0026] However, even for conventional cigarettes, especially so-called slim or ultra slim cigarettes, i.e. small diameter cigarettes, for example 5.0 mm to 6.5 mm, the filter / tip material needs to provide reduced filtering performance, increased cooling properties and improved tactile properties (hard but not too hard when gripped) compared to filter materials for king size cigarettes. Naturally, the smoke / flavor during burning is less than for king size cigarettes. A lower filtering performance is required so as not to further reduce the flavor. If only the amount of filter material is reduced to its limit, the filter hardness will eventually become unsatisfactory.

[0027] At the same fiber density, filters for slim or ultra-slim cigarettes also have a significantly higher resistance to draw than king size filters, which is generally undesirable.

[0028] For both HNB products and slim or ultra slim cigarettes, in order to achieve the desired reduced filtering performance with respect to condensable components such as tar as well as sufficient filter hardness, it has been proposed to increase the filament titer while maintaining the total titer, however, this approach has various drawbacks.

[0029] Cellulose-2,5-acetate is widely used today to manufacture filter elements, filter rods for cigarette filters, respectively. From the point of view of smoking and health, it has clearly superior properties with regard to certain retention phenomena. Filters made from cellulose acetate filter harmful nitrosamines and phenols much more efficiently than aggregates and nicotine. Moreover, smokers rate the taste of tobacco blend smoke combined with cellulose acetate filter elements as the most palatable. A further advantage of filter elements made from cellulose-2,5-acetate that is not underestimated can be found in the visual uniformity of the cut surface of the filters.

[0030] However, despite their significant market dominance, cellulose-2,5-acetate filter elements have some significant drawbacks: the filter rods have well-defined suction resistance and filtering performance due to structural and physical constraints.

[0031] The particle filtration or even condensate retention of a typical cellulose-2,5-acetate filter element is a function of filament titer (fineness of the fibers), filter diameter, resistance to suction and filter length.

[0032] 7. Assuming a normal filter diameter of 8 mm and a filter length of 21-25 mm, this becomes problematic when a filter performance significantly greater than 50% is required during the manufacture of the filter element, as is required when designing ultra-light cigarettes.

[0033] The same applies analogously to filter elements for slim or ultra slim cigarettes: since the smoke in the filter element flows parallel to the fibre direction, such filter elements can only be obtained by significantly reducing the filament titer, which at the same time results in a significant increase in the resistance to draw, while the total titer remains unchanged.

[0034] Therefore, the total titer and the filament titer must be correspondingly reduced, resulting in a dramatic decrease in the stiffness of the filter element, especially during smoking, a phenomenon known by those skilled in the art as "hot collapse" and generally considered undesirable. Summary of the Invention [Problem to be solved by the invention]

[0035] The present invention is based on the problem of specifying a filter element, in particular for so-called slim or ultra slim cigarettes, i.e. cigarettes with a small diameter, for example between 5.0 mm and 6.5 mm, which exhibits a sufficient filter hardness despite a reduced filtering performance and increased cooling. The filter element should furthermore be adjustable and capable of realizing a reduced resistance to draw, in particular compared to king size filters. [Means for solving the problem]

[0036] The present invention solves this problem by means of a filter element having the features of the independent claim 1, advantageous further developments of the inventive filter element being specified in the dependent claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The present invention therefore particularly relates to a filter element for a mouthpiece for use with a smoking product or HNB product, the filter element having a filter body made of a tow material formed by a plurality of monofilaments of cross-linked and crimped cellulose acetate filaments, the cellulose acetate filaments in particular presenting a multilobal or polygonal, preferably Y-shaped, cross-sectional shape.

[0038] The filter element according to the invention is characterized in particular by a particular filament strength selected for the cellulose acetate filaments of the tow material, the filament strength preferably being in the range of less than or equal to 10 denier and more than or equal to 5 denier.

[0039] Additionally, a relatively low total strength is selected for the tow material of the filter element of the present invention, preferably in the range of less than 10,000 denier and more than 5,000 denier.

[0040] Surprisingly, it has now been found that, despite a relatively low filament titer of 10 denier or less and a relatively low total titer of 10,000 denier or less, the totally undesirable hot collapse phenomenon can be effectively prevented even in the case of cigarettes of slim or ultra slim type, when a relatively low value for the specific fiber weight of the cellulose filaments of the tow material, i.e. the so-called specific acetate weight, of 2.5 mg or less per mm of filter element length is selected.

[0041] By using specifications for a relatively low filament titer, a relatively low total titer, and a relatively low specific fiber weight (acetate weight) of the cellulose acetate filaments, it is possible to realize a filter element that achieves the filter performance required in the engineering of slim or ultra-slim type cigarettes without significantly increasing the resistance to draw. These parameters make it possible to significantly increase the range of performance and applications achievable with the filter element.

[0042] In particular, the cellulose acetate filaments of the tow material are at least partially trilobal, i.e. star-shaped with three arms, in cross-section, which is well suited for allowing high filtration capacity by having the cellulose acetate filaments with the largest possible specific surface area, which may be desirable together with economical use of raw materials, as is the case, for example, in conventional cigarettes.

[0043] Alternatively, very fine filament bundles, for example of circular cross section, can be used to obtain the desired large specific surface area, however, other cross-sectional shapes for the cellulose acetate filaments are also contemplated, for example multilobal, polygonal or X-shaped cross-sections.

[0044] The tow material of the filter element of the present invention is formed from continuous stuffer box crimped cellulose acetate filaments by passing an approximately 30% solution of cellulose-2,5-acetate in acetone through a spinneret, evaporating the acetone in the spinneret, and collecting a plurality of cellulose acetate filaments (5000-10,000) into a strip and crimping it in a stuffer box.

[0045] The product is then dried, packed into storage containers and finally compressed into bales weighing between 300 and 600 kg.

[0046] After the bales of filter tow 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, whereby the filter tow is drawn in a drawing device with additives that serve to bond the filaments to form a three-dimensional roving, which is then introduced through an inlet funnel into a forming unit where it is cross-axially compressed, wound into paper, and cut into final lengths for the filter elements.

[0047] The additive applied to bond the filaments is usually a high boiling point solvent for cellulose acetate, such as glycerol triacetate (triacetin), which solubilizes the surface of the filament for a short time after application. When the two filaments come into contact, the excess additive migrates to the fiber surface and after some time, a permanent bond point is created, and the cellulose-2,5-acetate, which was a droplet, solidifies in the additive. The migration of the hardener described above results in a mechanically strong, three-dimensionally crosslinked filter rod with a low packing density after a storage period of less than one hour, which, due to its hardness, can be processed at high speeds without difficulty on modern cigarette machines.

[0048] For the tow material of the filter element according to the invention, choosing a relatively low filament titer, a relatively low total titer, and an acetate weight of 2.5 mg or less per mm of filter element length makes it possible to achieve a filter element that achieves the desired filtering performance with respect to condensable components, but still has sufficient filter hardness while maintaining a low total titer.

[0049] According to an embodiment of the filter element of the present invention, the monofilament cellulose acetate filaments of the tow material are at least partially formed as hollow and / or tubular cellulose acetate filaments.

[0050] What is particularly understood by hollow / tubular cellulose acetate filaments are preferably cylindrical filaments which, when viewed in cross section, exhibit one or more continuous cavities.

[0051] Such hollow fibers may be designed at least in part as multi-lumen hollow fibers. Compared to "solid" cellulose acetate filaments, single-lumen or multi-lumen tubular cellulose acetate filaments are relatively much more resistant to kinking, which allows particularly high Filtrona stiffness to be achieved without increased material compaction.

[0052] Because the filter element of the present invention comprises a filter body that may be based at least in part on cellulose acetate filaments that are at least partially formed as hollow cellulose acetate filaments, low resistance to draw and low filtering performance can be achieved because the filaments of the filter element that are at least partially formed as hollow cellulose acetate filaments have a low external surface area relative to the total fiber volume.

[0053] In this connection, it has surprisingly been found that a particularly high Filtrona hardness can be achieved with the present filter element due to the filaments being formed as partially hollow cellulose acetate filaments.

[0054] Indeed, it has been found that filter elements formed at least in part from hollow cellulose acetate filaments (hollow fibers) achieve the desired minimum Filtrona stiffness at a relatively low fiber weight per unit volume.

[0055] Because the filter element of the present invention is based on cellulose acetate filaments, the filter element of the present invention can be designed to form a uniform, white, smooth mouth-side front end, for example with respect to the tobacco rod of a cigarette, and can further achieve a selective phenol filtration effect.

[0056] On the one hand, the use of filter elements based on cellulose acetate filaments makes it possible to produce filter rods, in particular for cigarettes, which exhibit clearly superior properties with regard to certain retention phenomena from the smoking and health point of view.

[0057] Filters made from cellulose acetate filter harmful nitrosamines and phenols much more efficiently than aggregates and nicotine. Moreover, smokers rate the taste of today's conventional tobacco blends, such as "American Blend", "German Blend" and "Virginia", combined with filter rods made from cellulose acetate, as the most delicious. A further advantage of cellulose acetate filter rods that is not underestimated can be found in the visual uniformity of the cut surface of the filter.

[0058] With the filter elements of the present invention formed at least in part from hollow cellulose acetate filaments which function as a filler material according to embodiments, filter rods made from the materials of the present invention can have a wide range of different suction resistance and filtering capabilities.

[0059] In particular, it has been shown that filter materials consisting at least in part of hollow cellulose acetate filaments exhibit an improved thermal cooling effect. It has been determined that the use of hollow cellulose acetate filaments as a filler material still allows the achievement of a very low filtering effect, i.e. a retention effect on suspended solids and gases to be removed.

[0060] It is speculated that this effect is achieved by the hollow cellulose acetate filaments changing the surface area or flow rate of the gas or air being cleaned in such a way that only a small amount of potentially suspended matter is retained in the gas / air. Another reason may be that the use of hollow cellulose acetate filaments can achieve a different, particularly advantageous, filter material surface structure.

[0061] The filter element of the invention further has the advantage of allowing for particularly variable cooling of the heated particle-containing gas (particularly aerosol), so that the temperature of the gas, aerosol or water vapor taken in by the user of the smoking 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 adapted to the application.

[0062] It is further important to note that in the filter element of the present invention, the flow is essentially around the hollow cellulose acetate filaments (hollow fibers) and not through them. From geometrical considerations, it is clear that the interfiber distance is significantly greater than the lumen (hollow portion) of the hollow fibers. In this case, the viscosity of the aerosol (essentially air) results in the path of least resistance to be obtained (i.e., flow between the filaments and not through each individual filament).

[0063] In other words, in embodiments of the filter element of the present invention, the effective filtration surface is never maximized because there is no flow through the hollow cellulose acetate filaments in the tow material.

[0064] Thus, in particular, hollow cellulose acetate filaments can have kinks that close the lumen of the hollow cellulose acetate filaments without affecting the performance of the filter and / or filler material of the present invention with respect to set target parameters.

[0065] Of particular note in this context is that hollow cellulose acetate filaments realized as hollow fibers need not be continuously hollow, but rather may be partially closed by kinks. They may deviate from an ideal circular shape.

[0066] An embodiment of the invention provides that the hollow cellulose acetate filaments of the tow material act on the one hand as a support material and on the other hand as a cooling material, whereby a particularly compact filter element can be realized, whereby there is no need to increase the dimensions of the smoking article.

[0067] As used herein, the term "filtrona hardness" refers to the filter hardness determined according to the Filtrona principle. Under this principle, filter hardness is determined by pressing the flattened front end of a cylindrical rod with a diameter of 12 mm vertically onto a horizontally placed filter rod with a load of 300 g. The ratio of the compressed diameter to the initial diameter previously determined at the first contact gives the Filtrona hardness percentage.

[0068] The hardness of the filter element, or filter rod, respectively, is an important target criterion, especially for cigarette filters. It is typically indicated as the so-called Filtrona hardness. It should be emphasized that the Filtrona hardness is measured only on the filter element, but not on the original (raw) filter material, and thus on the tow material. The Filtrona hardness of the filter element is especially influenced by the amount of triacetin that can be or is sprayed on the filter element.

[0069] The minimum limit of Filtrona hardness is about 88%, which is set according to market requirements. Therefore, the Filtrona hardness of the filter element can be preferably set to about 88%-95%, particularly about 90%-93%.

[0070] A preferred embodiment of the filter element of the present invention provides a filter body, in particular as a filter rod, preferably having a diameter of about 6 mm to about 4 mm, in particular a diameter of about 5.5 mm to about 5.0 mm, preferably a diameter of about 5.35 mm, at least a portion of the filter body being wrapped in paper or a paper-like material.

[0071] The Filtrona hardness of the filter element is preferably greater than 85%, especially greater than 90%, in this embodiment.

[0072] Filtrona firmness is determined specifically by the acetate weight for a given filter element diameter, and the filament strength of the cellulose acetate filaments of the tow material has only a small effect on Filtrona firmness.

[0073] In the construction of the filter element of the present invention, a filter body is provided having an acetate weight of up to 2.5 mg per mm of filter element length.

[0074] The Filtrona hardness of the filter element can also be achieved with stronger filter wrap paper or stronger tipping paper.

[0075] Tipping paper is the paper by which multiple filter elements are bonded together or by which a filter element is bonded to a tobacco rod. However, increasing the Filtrona stiffness of a filter element by using stronger filter wrap paper or stronger tipping paper has economic drawbacks, as higher costs can be expected with this approach.

[0076] The Filtrona hardness of the filter element is subject to the so-called "hot collapse", which means that the filter hardness decreases as the filter element is used, i.e., as the filter element is smoked or used with an HNB product. This phenomenon can occur especially in traditional cigarettes when the filter element is heated in the presence of moisture during one of the final puffs, but this undesirable effect can also occur with HNB products.

[0077] In this context, it is shown that the degree to which Filtrona hardness decreases due to the "hot collapse" phenomenon can be significantly reduced when tow materials having the described low filament titer, the described low total titer and the low acetate weight are used as the substrate for the filter element of the present invention.

[0078] The tow material of the filter body of the filter element of the present invention is preferably 0.3 mm 2 / g~0.025m 2 / g range, especially 0.15m 2 / g. Thus, the resistance to draw and filtering performance of the filter element of the present invention can be reduced without a reduction in the length of the filter element. Thus, relatively long filter elements can be realized that allow for correspondingly long cooling sections, which is advantageous in terms of heat balance, especially when the filter element is used with HNB products.

[0079] In addition, especially 0.15m 2 The inventive specification of the mass specific surface area of ​​the tow material at a value less than 1 / g allows the resistance to suction and filtering performance of the filter element to 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, which has the advantage that there is no reduction in the Filtrona hardness of the filter element due to the reduction in the fiber weight in the filter element material per volume fraction and / or due to the reduction in the total titer.

[0080] The cellulose acetate filaments of the tow material serving as the base product for producing the filter element of the invention are in particular cellulose-2,5-acetate, cellulose butyrate, cellulose acetate butyrate, cellulose acetate propionate and / or cellulose propionate filaments. The cellulose acetate filaments preferably have a degree of substitution of about 1.5 to 3.0, preferably about 2.2 to 2.6.

[0081] For example, plasticizers preferably used for plasticizing cellulose acetate fibers and applied to the fibers can be selected from the following group: glycerol esters (especially glycerol triacetate), ethylene and propylene carbonates, citrate esters (especially acetyl citrate, triethyl citrate), glycose esters or diethylene glycol dibenzoate.

[0082] Those skilled in the art are familiar with the amount of plasticizer and / or water-soluble binder used. Generally, there is a plasticizer and / or binder content of about 1-14% by weight, although in special cases the plasticizer content can easily exceed this range.

[0083] The water-soluble binders preferably present on the surface of the cellulose acetate filaments may in particular be high-boiling solvents applied to the monofilaments or tow material of the tow material, such as polyalkylene oxides, water-soluble esters or ethers, starch, starch derivatives, p-polyvinyl alcohol, polyvinyl ethers, p-polyvinyl acetate and / or polysaccharides, water-soluble polyamides and polyacrylates.

[0084] In this case, it was particularly recognized that the residual curl (RS) of the tow material of the filter body and the density (ρ) of the filter body also have a significant influence on the performance of the filter element. Thus, the density value A related to the residual curl is preferably at least 0.016 mg / m2, with respect to 2 / mm 6 Is:

number

[0085] The residual crimp (RS) of the tow material of the filter body should in particular not exceed a value of 3.0, in particular not exceed a value of 2.75, and the residual crimp (RS) of the tow material is preferably from about 1.5 to about 2.75, in particular from 1.9 to 2.5.

[0086] Residual curl is understood as the ratio of the length of the final crimped cellulose acetate filament to the length of the filter element. Residual curl is a characteristic that characterizes a given filter element.

[0087] Surprisingly, it has been found that, under the same acetate weight, a relatively low total strength of the filter body tow material requires a higher residual crimp value to maintain the required filter firmness.

[0088] A further aspect of the invention relates to identifying a tow material for manufacturing a filter element for a mouthpiece to be used with a smoking product or HNB product, the tow material being optimized for the effectiveness of the filter element manufactured therefrom, and exhibiting the most consistent performance possible, particularly with regard to filtering performance and filter hardness.

[0089] In this context, it has also been determined that it is particularly important that the cellulose acetate filaments of the tow material exhibit a uniform, in particular predefined (predetermined) or definable, filament titre, this uniform, predefined or definable, filament titre being in particular within the range of 5 to 10 denier.

[0090] To achieve consistent performance of filter elements made from the tow material, especially with respect to filtering performance and filter hardness, the coefficient of variation of the uniform filament titer should be a maximum of 0.1, preferably a maximum of 0.05 to a maximum of 0.01.

[0091] The coefficient of variation of the uniform filament titer, also called the coefficient of deviation, is a statistical parameter that, in contrast to the variance, characterizes the relative measure of the distribution, i.e., it is independent of the units of measurement of the statistical or random variable.

[0092] In other words, what is guaranteed during the production of the tow material is that the individual filaments produced by each used spinneret of the spinning machine exhibit a uniform filament titer.

[0093] This can be achieved in practice by assigning each spinneret to its own, in particular frequency-controlled, spinning pump, thereby ensuring that each spinneret of the spinneret is supplied with spinning fluid (a solution of about 30% cellulose-2,5-acetate in acetone) in such a manner that a uniform nozzle pressure and a uniform amount of spinning fluid can be delivered from each spinneret per unit time.

[0094] This approach, which is easily realizable but nevertheless effective, makes it possible to achieve a uniform filament titer, in particular one that is predefined or definable.

[0095] Alternatively or additionally, it is preferred that the monofilaments of the tow material formed from the cellulose acetate filaments exhibit a uniform total titer, in particular a predefined or definable titer of at least 5000 denier and at most 10,000 denier, the coefficient of variation of the uniform total titer being preferably at most 0.1, in particular at most 0.05 to at most 0.005, the coefficient of variation being in particular determined by multiple measurements over the length of the tow.

[0096] This measure, which is easily implemented, can effectively prevent quality variations during the production of the filter element of the present invention, which are unacceptable especially in the slim and ultra slim type filter market and therefore entail productivity losses during the production of the filter element.

[0097] The advantages associated with the present invention are therefore many: in particular, it is possible to realize slim and ultra-slim type filter elements in which the occurrence of the high temperature collapse phenomenon is effectively prevented, even when the tow material of the filter body has a relatively low total titer and a relatively low filament titer.

Claims

1. 1. A filter element for a mouthpiece for use in a smoking product or HNB product, comprising: The filter element has a filter body made of a tow material, the tow material being formed by a plurality of monofilaments of crosslinked and crimped cellulose acetate filaments, the cellulose acetate filaments in particular exhibiting a multilobal or polygonal, preferably Y-shaped, cross-sectional shape: the cellulose acetate filaments of the tow material exhibit a uniform filament titre, which is in particular predefined or definable and ranges from less than or equal to 10 denier (11.1 dtex) to more than or equal to 5 denier (5.5 dtex); - said tow material has a total titer in the range of less than or equal to 10,000 denier (11.1 kdtex) and more than or equal to 5,000 denier (5555.5 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 of filter element length and is greater than or equal to 1.0 mg per mm of filter element length; Filter element.

2. 2. The filter element according to claim 1, wherein the coefficient of variation of said uniform total titer is at most 0.1, preferably at most 0.05 to at most 0.

005.

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

01.

4. The filter body is in particular embodied as a filter rod and preferably has a diameter of about 6 mm to about 4 mm, in particular a diameter of about 5.5 mm to about 5.0 mm, preferably a diameter of about 5.35 mm, At least a portion of the filter body is wrapped in paper or a paper-like material. A filter element according to any one of claims 1 to 3.

5. 5. A filter element according to claim 4, wherein the filter body with the paper or paper-like wrapping has a compression depth of less than 0.90 mm, in particular less than 0.85 mm, when a face end of a cylindrical test piece having a mass of 300 g and a diameter of 12 mm is placed on the filter body perpendicular to the filter body axis.

6. 5. A filter element according to claim 4, wherein the filter body without the paper or paper-like wrapping has a compression depth of less than 0.90 mm, in particular less than 0.85 mm, when a face end of a cylindrical test piece having a mass of 300 g and a diameter of 12 mm is placed on the filter body perpendicular to the filter body axis.

7. 7. The filter element of claim 1, wherein at least some of the cellulose acetate filaments of the monofilaments of the tow material are at least partially formed as hollow and / or tubular cellulose acetate filaments.

8. The filter element according to any one of claims 1 to 7, wherein the hardness of the filter body reaches at least 80% of Filtrona hardness, preferably at least about 86% of Filtrona hardness.

9. The filter body contains a plasticizer and has a plasticizer content of about 2% to about 15%, preferably about 4% to about 10%, the plasticizer including, inter alia, triacetin, triethylene glycol diacetate and / or citric acid ethyl ester; A filter element according to any one of the preceding claims.

10. The tow material of the filter body exhibits a residual curl (RS) and a density (ρ), and a relationship value A between the residual curl and the density is as follows: [0010] At least 0.016 mg ２ / mm ６ The filter element according to any one of claims 1 to 9,

11. A filter element according to any one of claims 1 to 10, in particular claim 10, comprising A filter element, wherein the residual curl (RS) of the tow material of the filter body does not exceed a value of 3.0, and the residual curl (RS) of the tow material of the filter body is preferably between about 1.5 and about 2.75, in particular between 1.9 and 2.

5.

12. The filter element of 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.

13. A tipping tip for use with a smoking product or HNB product, comprising a filter element according to any one of claims 1 to 12.

14. The tip of claim 13, A tipping member, in particular a capsule-shaped or capsule-like flavour-releasing element, furthermore integrated into said filter element.

15. A cigarette filter or cigarette filter element comprising a filter element according to any one of claims 1 to 12.

16. 16. A cigarette filter or cigarette filter element according to claim 15, wherein a flavour releasing element, in particular a capsule-shaped or capsule-like flavour releasing element, is further integrated into said filter element.

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