Title - FILTER ELEMENT FOR MOUTHPIECES FOR USE WITH SMOKING PRODUCTS OR HNB PRODUCTS

Abstract

The invention relates to a filter element for mouthpieces for use with smoking products or HNB products, wherein the filter element has a filter body made of a tow material, wherein the tow material is formed from a plurality of individual filaments of crosslinked and curled cellulose acetate filaments, wherein the cellulose acetate filaments in particular exhibit a polygonal and preferably Y-shaped cross-sectional geometry, and wherein the tow material has a specific surface area related to mass of less than 0.15 m² / g, in particular less than 0.3 m² / g, and greater than 0.025 m² / g.

Description

FILTER ELEMENT FOR MOUTHPIECES FOR USE WITH SMOKING PRODUCTS OR HNB PRODUCTS Description The invention relates to a filter element for mouthpieces for use with smoking products or HNB products, as well as the use of said filter element in mouthpieces for smoking products or in cigarette filters or mouthpieces for HNB products, respectively. Smoking products within the meaning of the present invention refer to traditional tobacco products, cigarettes in particular, but also pipes and marijuana products, as well as so-called heat-not-burn (HNB) products, vaping products and so-called hybrid products. Depending on the application, mouthpieces for smoking products have different functions. For example, mouthpieces can act as filter devices to remove harmful components from a stream of tobacco smoke, such as condensed substances, particularly tar, as well as particles carried by the smoke stream. This filtering function is particularly useful with conventional tobacco products. A mouthpiece can be formed as an integral part of a cigarette or cigar, creating a "tip" on the cigarette / cigar. Another example of a different type of mouthpiece is an interchangeable device, such as a replaceable filter element that can be detached after use. Such mouthpieces are housed in suitable holders, e.g., a cigarette holder or a pipe mouthpiece. A mouthpiece formed as an integral part of a cigarette is the cigarette filter. The cigarette filter is intended to reduce the percentage of harmful substances, such as condensation and gas, found in cigarette smoke. Additionally, the filter makes the smoke somewhat smoother or more flavorful for a large percentage of smokers. In a cigarette with 1985077 of 17 conventional filter, the filter is wrapped in filter paper and is connected to the tobacco stick through the so-called mouthpiece paper, by which most industrially manufactured cigarettes are provided with a filter. There are numerous types of filter materials already in use, particularly for reducing substances in tobacco smoke before they reach the smoker's respiratory system. However, in addition to removing large quantities of harmful substances, a satisfactory filter also needs to be effective without unduly obstructing the passage of air or smoke through the filter and thus requiring excessive drag. Furthermore, when using filters for tobacco smoke, the filter material should not impart its own flavor and thereby alter the taste of the tobacco smoke. The present invention relates not only to filter materials for the aforementioned conventional tobacco applications, but in particular also to filter materials and / or filter elements for mouthpieces used in smoking products, so that these filter elements in particular have other functions besides a simple filtering function. In other applications, a filtering function is by no means the priority for mouthpieces. This applies, for example, to heat-not-burn (HNB) products, which have become increasingly popular in recent years. In these devices, a portion of the processed tobacco is heated by a heat source during use, but it is not burned. The volatile components of the tobacco, such as flavorings, nicotine, glycerin, and water, are vaporized and carried in the air that the user inhales through the HNB product. As the released substances cool, an aerosol is formed that the user inhales. 1985077 of 17 In general, commercially available HNB products comprise a device consisting of a power supply that feeds a heating element and a separate consumable product consisting of a portion of processed tobacco, a support element such as, for example, a tubular segment of cellulose acetate, a so-called cooling element arranged downwards in the flow direction, for example, in the form of a curled polylactide film packaged in a cylinder with numerous axial channels, and a filter on the mouthpiece side. The consumables are inserted into the device before use, so that the heating element heats the tobacco portion when the HNB product is used. For example, in a Philip Morris product called IQOS / HEETS, a heating blade in the device pierces the tobacco portion.An IQOS / HEETS product refers to an IQOS device with its associated HEETS consumable product marketed by Philip Morris. The HEETS consumable is a heat-not-burn product in which the tobacco is simply heated rather than burned. A competitor to BAT (“Glo”) heats the tobacco from the outside, so the so-called cooling element is replaced by a tube. In these devices, too, a portion of the processed tobacco is heated by a heat source during use, but it is not burned. The volatile components of the tobacco, such as flavorings, nicotine, glycerin, and water, vaporize and are trapped in the air that the user inhales through the HNB product. As the released substances cool, an aerosol is formed that the user inhales. Known consumable products for this application have the disadvantage that their mouth-side filters can become significantly heated due to their proximity to the heating element and the hot steam produced during use of the HNB product. 1985077 of 17 In so-called hybrid products, an aerosol generator (propylene glycol, glycerin) is first vaporized; cooling produces an aerosol. This aerosol is directed through a portion of processed tobacco and inhaled by the user. Also in such applications, the mouthpiece has the specific function of protecting the end on the user's side from overheating to a degree that is uncomfortable for the user. Unlike conventional tobacco products that burn tobacco, in the case of HNB product consumables it may be desirable that the elements disposed downwards from the heated tobacco portion in the flow direction, such as the cooling element and mouth-side filter, have only a low filtration effect with respect to condensed components such as tar, since substantially smaller quantities of these components can be formed. The invention relates to specifying a filter element for mouthpieces for use with smoking products or HNB products, where the filter element is suitable for a wide range of smoking product applications. In particular, a filter element with low draw resistance and low filtration efficiency is specified, exhibiting a sufficiently high filter hardness that remains as constant as possible when used in smoking products, and where the filter element can nevertheless be manufactured in a particularly economical manner. In addition, the filter element must exhibit in particular a selective filtration effect on phenols and be suitable for reliably cooling a heated gas laden with particles in order to reduce the temperature of the gas, aerosol or vapor absorbed by the user of a smoking product. These and other tasks are solved by the object of main claim 1. 1985077 of 17 Accordingly, the invention relates in particular to a filter element for mouthpieces for use with smoking products or HNB products, wherein the filter element has a filter body made of a tow material, wherein the tow material is formed from a plurality of individual filaments of cross-linked and curled cellulose acetate filaments, and wherein the cellulose acetate filaments in particular exhibit a polygonal cross-section geometry and, preferably, a Y-shaped geometry. With a filter element of this type, it was surprisingly found that when the tow material exhibits the lowest possible specific surface area relative to mass, the desired reduced filtration performance with respect to condensable components such as tar, as well as sufficient filter hardness, can be achieved, particularly while retaining the full grade of the tow material. The tow material of the filter element of the invention must, in particular, have a specific surface area relative to mass of less than 0.3 m² / g, specifically less than 0.15 m² / g and greater than 0.025 m² / g. This specific surface area relative to mass value, preferably between 0.3 m² / g and 0.025 m² / g, can significantly increase the performance and the range of applications achievable with the filter element. According to preferred embodiments of the filter element of the invention, the cellulose acetate filter elements of the tow material exhibit at least a partially trilobal, i.e., three-armed star-shaped cross-section. Such a cross-sectional shape is suitable when the cellulose acetate filaments must have the largest possible specific surface area to allow for high filtration capacity (if desired, as is the case with conventional cigarettes, for example) along with the simultaneous economical use of raw materials. Alternatively, it is possible to obtain the 5 1985077 of 17 large desired specific surface area using a bundle of extremely fine filaments of, for example, circular cross-section. However, other cross-sectional shapes for cellulose acetate filaments are also conceivable, such as, for example, a polygonal or four-sided cross-sectional shape. The filter element material of the invention consists of continuous box-filled cellulose acetate filaments. A solution of approximately 30% cellulose-2,5-acetate in acetone is pressed through spinnerets, the acetone evaporates in a spinning chamber, a plurality of cellulose acetate filaments are gathered into a strip and then crimped in a box filler. The product is then dried and usually pressed into bales. The filter element material (“filter tow”) is taken from the bales and processed into filter bars in a filter bar machine. The filter tow is thus drawn out in a drawing device, provided with an additive that serves to bond the cellulose acetate filaments, compressed transversely after forming a so-called wick, and optionally wrapped in paper and cut to the final length of the filter element.By selecting a specific surface area related to the mass, particularly in a range of less than 0.3 m² / g, and in particular less than 0.15 m² / g, and greater than 0.025 m² / g for the tow material of the filter element of the invention, a filter element can be made that achieves a desired reduced filtration performance with respect to the condensable components and yet achieves sufficient filter hardness with full retention of the titer. According to embodiments of the filter element of the invention, the cellulose acetate filaments of the individual filaments of the tow material are formed, at least partially, as hollow and / or tubular cellulose acetate filaments. 1985077 of 17 In particular, hollow / tubular cellulose acetate filaments should preferably be understood to mean cylindrical filaments exhibiting one or more continuous cavities when viewed in cross-section. Such hollow fibers can be designed, at least partially, as multi-lumen hollow fibers. Compared to “solid” cellulose acetate filaments, multi-lumen single-lumen tubular cellulose acetate filaments are considerably more resistant to torsion, allowing for particularly high Filtrona hardness to be achieved without increasing material compression. According to embodiments of the present invention, the hollow cellulose acetate filaments exhibit at least a partially trilobed shape; that is, a three-armed star-shaped cross-section. Such a cross-sectional shape is suitable when the cellulose acetate filaments must have the largest possible specific surface area to allow for high filtration capacity along with, for example, the simultaneous economical use of raw materials. Alternatively, the desired large specific surface area can be obtained using a bundle of extremely fine filaments with a circular cross-section. However, other cross-sectional shapes for the hollow cellulose acetate filaments are also conceivable, such as, for example, a four-sided cross-section. Because the filter element of the invention comprises a filter body capable of being based at least in part on cellulose acetate filaments that are at least partially formed as hollow cellulose acetate filaments, low draft resistance and low filtration efficiency can be achieved, since the filaments of the filter element are at least partially formed as hollow cellulose acetate filaments. 1985077 of 17 cellulose have a small external surface area in relation to the total volume of fiber. In this context, it was surprisingly found that, because the filaments are 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 from hollow cellulose acetate filaments (hollow fibers) achieve the desired minimum filter hardness with a lower fiber weight per unit volume. Since the filter element of the invention is based on cellulose acetate filaments, the filter element of the invention is designed to form a uniform, white, smooth mouth-side front end for a tobacco bar of, for example, a cigarette, so that a selective phenol filtration effect can also be achieved. The use of a filter element based on cellulose acetate filaments, on the one hand, allows the production of filter rods particularly for cigarettes which, from the point of view of smoking and health, have shown outstanding properties demonstrable in relation to specific retention phenomena. A filter made of cellulose acetate filters out harmful nitrosamines and phenols much more efficiently than condensate and nicotine. Furthermore, smokers rate the flavor of today's common tobacco blends, such as "American Blend," "German Blend," and "Virginia," when combined with a cellulose acetate filter rod as the most palatable. Another advantage of a cellulose acetate filter rod that should not be underestimated is the optical homogeneity of the filter's cut surfaces. The filtering element of the invention is formed at least partially from hollow cellulose acetate filaments that 1985077 of 17 serve as filler material according to the embodiments, there may be a wide range of draft resistance and variable filtration performance in the filter rods made of the material of the invention. In particular, a filter material consisting at least partially of hollow cellulose acetate filaments has been shown to exhibit an enhanced thermal cooling effect. It was determined that using hollow cellulose acetate filaments as a packing material could still achieve a very low filtration effect—that is, a retention effect—for removing suspended solids and gases. This effect is thought to be achieved because the hollow cellulose acetate filaments alter the surface or flow of the gas or air being cleaned, retaining only marginal amounts of any potentially suspended matter. Another reason could be that using hollow cellulose acetate filaments allows for a different, and particularly advantageous, filter material surface structure. The filter element of the invention also has the advantage of allowing, in particular, the variable cooling of a heated, particle-laden gas (particularly aerosol) so that the temperature of the gas, aerosol, or vapor absorbed by the user 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 packing material, the desired cooling effect can be specifically tailored to the application. It is also important to note that, in the filter element of the invention, the flow passes essentially around the hollow cellulose acetate filaments (= hollow fibers) and, to a lesser extent, through them. From geometric considerations, it is obvious that the distances between fibers are considerably greater than the lumen (hollow portion) of the fiber. 1985077 of 17 hollow. The viscosity of the aerosol (substantially air) then causes it to take the path of least resistance (i.e., it flows between the filaments and not through each individual filament). In other words, the operative filtration surface is not maximized in any way in the embodiment of the filter element of the invention since there is no flow through the hollow cellulose acetate filaments in the tow material. In particular, the hollow cellulose acetate filaments can therefore have folds that close the lumen of the hollow cellulose acetate filaments without this having an effect on the performance of the filter and / or filling material of the invention with respect to the established target parameters. In particular, it should be noted in this context that hollow cellulose acetate filaments manufactured as hollow fibers do not have to be continuously hollow, but can also be partially closed by folding. They can also deviate from an ideal circular shape. The embodiments of the invention provide that the hollow cellulose acetate filaments of the tow material serve, on the one hand, as a support material and, on the other hand, as a cooling material. By using the hollow cellulose acetate filaments that simultaneously serve as a support material, particularly compact filter elements can be made, thus not requiring an increase in the dimensions of the smoking product. The term “Filtrona 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 against a horizontally placed filter rod with a 300 g load. The ratio between the compressed diameter and the diameter 1985077 of 17 initial previously determined in the first contact gives the percentage of Filtrona hardness. The filter element, or the hardness of the filter rod, is an important objective criterion, especially for cigarette filters. It is usually referred to as the Filtrona hardness. It's important to note that Filtrona hardness is only measured on the filter element itself, not on the underlying (raw) filter material, i.e., the tow material. The Filtrona hardness of a filter element is particularly influenced by the amount of triacetin sprayed onto it. The minimum Filtrona hardness limit is approximately 88% and is geared towards market requirements. The Filtrona hardness of the filter element can therefore be preferably adjusted to approximately 88% to 95%, specifically approximately 90% to 93%. Preferred embodiments of the filter element of the invention provide that the filter body is made in particular as a filter rod and preferably with a diameter of between approximately 8 mm and approximately 5 mm and, in particular, a diameter of approximately 7.8 mm or approximately 5.35 mm, wherein at least a part of the filter body is wrapped in paper or paper-like material. The filter hardness of the filter element should preferably be greater than 85% in this embodiment and, in particular, greater than 90%. The Filtrona hardness is dictated particularly by the fiber weight per volume for a given filter diameter, so the filament count of the cellulose acetate filaments of the tow material has only a minor influence on the Filtrona hardness. 1985077 of 17 The filter element configurations of the invention provide that the filter body has a fiber weight that amounts to a maximum filter element length of 10 mg / mm. The filter element's filter hardness can also be achieved by using stronger filter wrap paper or stronger tip paper. Tip paper is a paper in which several filter elements are connected together, or a filter element is connected to a tobacco rod. However, increasing the filter element's strength by using a stronger filter wrap or mouthpiece paper has economic disadvantages, as higher costs can be expected with this approach. Associated with the filter element's filter hardness is the so-called "hot collapse," in which the filter's hardness decreases as the filter element is used; that is, the filter element used with smoking products or HNBs. 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. It has been demonstrated in this context that the degree to which the Filtrona hardness is reduced due to the “hot collapse” phenomenon can be significantly reduced when a tow material having the specific surface area related to the cited mass of less than 0.15 m2 / g is used as the base material of the filter element of the invention. Because the tow material of the filter body of the filter element of the invention has a specific surface area related to mass ranging from 0.3 m² / g to 0.025 m² / g, and in particular being less than 0.15 m² / g, the draft resistance and filtration performance of the filter element of the invention can be reduced without reducing the 12 1985077 of 17 filter element length. In this way, relatively long filter elements can be made, allowing for a correspondingly long cooling section, which is advantageous in relation to thermal balance, especially when the filter element is used with HNB products. Furthermore, the inventive design of the specific surface area relative to the mass of the tow material to a value particularly lower than 0.15 m² / g allows for a reduction in draft resistance and filtration performance of the filter element without reducing the fiber weight in the filter element per volume fraction and / or without reducing the total count of the tow material. This has the advantage that there is no reduction in the filter hardness of the filter element due to a reduction in the fiber weight in the filter element per volume fraction and / or due to a reduction in the total count. According to embodiments of the filter element of the invention, the filter body has a fiber weight of 10 mg / mm of maximum filter element length. The tow material, which constitutes the base product for the production of the filter element of the invention, must exhibit in particular an overall count of 10,000 to 40,000 denier. The cellulose acetate filaments of the tow material that serve as the base product for producing the filter element of the invention are, in particular, cellulose-2,5-acetate filaments, cellulose butyrate, cellulose acetate butyrate, cellulose acetate propionate, and / or cellulose propionate. 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 used preferably for the plasticizing and in particular the thermoplasticizing of cellulose acetate fibers and applied to the fibers can be selected, for example, from the following groups: glycerol ester (in particular glycerol triacetate), 13 1985077 of 17 ethylene and propylene carbonate, citric acid ester (particularly acetyl citrate, triethyl citrate), glucose ester or diethylene glycol dibenzoate. The expert in this field of technology knows the amount of plasticizer and / or water-soluble binder to use. Generally, the plasticizer and / or binder content is approximately 1 to 14% by weight; in special cases, however, the plasticizer content can easily exceed this range. Water-soluble binding agents, which are preferentially present on the surface of the cellulose acetate filaments, may be, in particular, high-boiling-point solvents applied to the individual filaments of the tow material or to the tow material, such as water-soluble polyalkylene oxides, esters or ethers, starches, starch derivatives, p-polyvinyl alcohols, polyvinyl ethers, p-polyvinyl acetates and / or water-soluble polysaccharides, polyamides and polyacrylates. Particularly recognized in the present case was that the residual curl (RS) of the filter body's tow material and the filter body's density (p) also have a significant impact on the filter element's performance. Therefore, a density value A related to the residual curl is preferably at least 0.016 mg² / mm⁶, with: A = p² * RS. The residual curl (RS) of the tow material of the filter body in particular should not exceed the value of 1.7, and in particular the value of 1.45, so the residual curl (RS) of the tow material is preferably between approximately 1.05 and approximately 1.4 and in particular between 1.1 and 1.3. Residual curl is therefore understood as the ratio between the length of the final curled cellulose acetate filament and the length of the 1985077 of 17 filter element. Residual ripple is a characteristic feature of a given filter element. Another aspect of the present invention relates to the specification of a hemp material for producing a filter element for mouthpieces used with smoking products or HNB products, wherein the hemp material is optimized for the effect of the filter elements produced from the hemp material exhibiting the most uniform performance possible, particularly in terms of filtration performance and filter hardness. In this context, it was determined that it is also particularly important that the cellulose acetate filaments of the tow material exhibit a specific, predefined or definable uniform filament count. This predefined or definable uniform filament count is specifically within a range of 8 to 30 denier, preferably within a range of 9 to 30 denier, and most preferably between 10 and 20 denier. To achieve uniform performance of the filter element made of tow material, particularly with regard to filtration performance and filter hardness, the coefficient of variation of the uniform filament count should be at most 0.1 and preferably from 0.05 at most to 0.01 at most. The coefficient of variation of the uniform filament count, which can also be called the deviation coefficient, is a statistical parameter and characterizes, unlike the variance, a relative measure of dispersion; 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 tow material, it is ensured that the individual filaments produced by the spinnerets used respectively of the spinning machine have a uniform filament count. 1985077 of 17 This can be done in practice by assigning each spinner to its own frequency-controlled spinning pump to ensure that each spinneret of the spinning machine is supplied with the spinning fluid (approximately 30% cellulose-2,5-acetate solution in acetone) in such a way as to allow a uniform nozzle pressure and a uniform amount of spinneret delivered from each spinneret per unit of time. This easily achievable, yet effective, approach allows for a predefined or specifically definable uniform filament count. Alternatively or in addition to this, it is preferable that the individual filaments of the tow material formed from the cellulose acetate filaments exhibit a predefined or definable and preferably uniform filament count of at least 200 denier and at most 4000 denier, and preferably at least 250 denier and at most 2500 denier, wherein a coefficient of variation of the uniform filament count herein preferably has a maximum of 0.1 and in particular 0.05 at most up to 0.01 at most. 1985077 of 17 CLARKE MODET & CO. (ARGENTINA) SA - 30540437455 Digitally signed by PORTALTRAMITES - INPI Date: 2022.09.30 10:07:19 -03:00 Reason: Digitally Signed by the INPI Location: Buenos Aires, Argentina 1985077

Claims

1. A filter element for mouthpieces for use with smoking products or HNB products, characterized in that the filter element has a filter body made of a tow material, wherein the tow material is formed from a plurality of individual crosslinked and curled cellulose acetate filaments, the cellulose acetate filaments in particular exhibiting a polygonal and preferably Y-shaped cross-sectional geometry, and wherein the tow material has a mass-related specific surface area of ​​less than 0.15 m² / g and more than 0.025 m² / g, and wherein the tow material of the filter body has a residual crimp (RS) and a density (ρ), wherein a residual crimp-related density value A is at least 0.016 mg² × mm⁶, with: A = ρ² * RS. Thirteen claims follow.