EP4076045B1 - Method for manufacturing a filter material and/or filler material for mouthpieces for use with smoking products or hnb products, mouthpieces and cigarette filters comprising such a filter material and/or filler material - Google Patents

Description

The present invention relates to a method for producing a filter and/or filling material for mouthpieces for use with smoking products or HNB products, and further to a mouthpiece for use with smoking products or HNB products, the mouthpiece having a filter and/or filling material, which is produced by such a process; and finally a cigarette filter or cigarette filter element, which has a filter and/or filling material which is produced using such a method.

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.

Depending on the application, mouthpieces for using smoking products have different functions. On the one hand, mouthpieces can serve as a filter device, for example to remove harmful components from a stream of tobacco smoke, such as condensed substances such as tar, as well as particulate matter entrained by the stream of smoke Matter to pull out. This filter function is particularly used in classic tobacco applications. A corresponding one can be used Mouthpiece can be designed as an integral part of a cigarette or a cigarillo and thus form a "tip" on the cigarette or on the cigarillo.

Another type of mouthpiece is replaceable devices, such as replaceable filter elements, which can be removed after use. Such mouthpieces are accommodated in corresponding holders, for example in a cigarette holder or in a pipe mouthpiece.

A mouthpiece designed as an integral part of a cigarette is the cigarette filter. The cigarette filter is intended to prevent the presence of harmful substances such as condensate and gases in the smoke of the cigarette. In addition, the filter makes the smoke somewhat milder or more pleasant for a large proportion of smokers. In a classic filter cigarette, the filter is covered in filter wrapping paper and is coupled to the tobacco rod with the so-called tipping paper, whereby most industrially manufactured cigarettes are provided with a filter. Self-rollers can buy these from tobacco shops.

Numerous types of filter materials are already used, in particular to reduce the content of the ingredients in tobacco smoke before it reaches the smoker's respiratory system. In addition to removing the harmful components in large quantities, a satisfactory filter must also be effective without undesirably impeding the passage of air or smoke through the filter so that excessive draft is required. When used in tobacco smoke filters, the filter material must not change the taste of the tobacco smoke by adding its own taste.

Another important factor in the production of a satisfactory tobacco smoke filter is that its production is not too complex so that the final price of the smoking article in which the filter is used does not rise too high.

However, the present teaching relates less to filter materials for the classic tobacco applications described above, but rather in particular to filter and/or filling materials for mouthpieces for the use of smoking products, with these filter and/or filling materials in particular having other functions than just a filter function.

In other applications, the filter function of the mouthpieces is by no means a priority. This applies, for example, to heat-not-burn products ("HNB products"), which have become increasingly popular in recent years. In these devices, a portion of processed tobacco is heated by a heat source during use but is not burned. Volatile tobacco components, such as flavorings, nicotine, glycerin and water, evaporate and are carried away by the air that is drawn through the HNB product by the user. As the released substances cool, an aerosol is formed which is inhaled by the user.

Commercially available HNB products usually include a device consisting of a power supply that supplies a heating element and a separate consumable item consisting of a portion of processed tobacco, a support element, such as a tubular cellulose acetate segment, a so-called cooling element downstream in the direction of flow, for example in the form of a crimped polylactide film, which is gathered into a cylinder with many axial channels, and a mouth-side filter. The consumables are placed into the device before use in such a way that the heating element heats the portion of tobacco when the HNB product is used.

For example, in a so-called IQOS/HEETS product from Philip Morris, the tobacco portion is skewered onto a heating blade in the device. An IQOS/HEETS product is an IQOS device marketed by Philip Morris with the associated HEETS consumable item. The HEETS consumable is a heat-not-burn product in which tobacco is simply heated instead of burning it.

A competing product from BAT ("Glo") heats the tobacco from the outside, with the so-called cooling element replaced by a tube. In these devices, too, a portion of processed tobacco is heated by a heat source during use but is not burned. Volatile tobacco components, such as flavorings, nicotine, glycerin and water, evaporate and are carried away by the air that is drawn through the HNB product by the user. As the released substances cool, an aerosol is formed which is inhaled by the user.

The consumables known for this application have the disadvantage that their mouth-side filters can heat up considerably due to the proximity to the heating element and due to the hot steam generated when using the HNB product.

With so-called hybrid products, an aerosol former is first evaporated (propylene glycol, glycerin), and an aerosol is formed by cooling. This aerosol is passed through a portion of processing tobacco and inhaled by the consumer. Even in such applications, the mouthpiece has the particular function of protecting the user-side end against heating that is unpleasant for the user.

In contrast to conventional tobacco products in which tobacco is burned, with consumables of HNB products it may be desirable that the elements downstream of the heated tobacco portion in the direction of flow, such as the cooling element and the mouth-side filter, only have a small filtering effect with regard to condensed components such as tar because these smoke components can be produced in significantly smaller amounts.

• Zugwiderstand
• Filtrationsleistung
• Filterstabhärte/Filtronahärte
• Optik
• Wirtschaftlichkeit der Herstellung
• Rauchtemperatur

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

• tensile resistance
• Filtration performance
• Filter rod hardness/Fitrona hardness
• optics
• Economics of production
• Smoke temperature

The filter rod hardness is an important target criterion for cigarette filters. It is usually stated as the so-called Filtrona hardness. The Filtrona hardness is determined by holding a cylindrical rod of 12 mm diameter with its flat The front side is pressed 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 touch results in the percentage of Filtrona hardness.

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

The minimum limit of Filtrona hardness is around 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%.

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

Occasionally a higher Filtrona hardness is also achieved by using a stronger filter wrapping paper or a stronger tipping paper. A tipping paper is a paper with which either several filter elements are coupled together or filter elements are coupled to the tobacco rod. However, increasing Filtrona hardness by using a stronger filter wrapping paper or a stronger tipping paper has economic disadvantages as higher costs are expected with this approach.

The so-called “hot collapse” is related to Filtrona hardness, in which the filter hardness decreases during smoking. This can occur in particular if the filter of a classic cigarette heats up in the presence of moisture during one of the last puffs. This undesirable effect can also occur with HNB products.

In addition to a Filtrona hardness that is as constant and high as possible when using a smoking product, the mouthpiece material should also show a predetermined or determinable filtration performance. The filtration performance in relation to condensed matter (droplets, particles), also known as condensate or tar, is of interest for conventional tobacco products and HNB products, as a large number of substances with negative health relevance can be found in the condensed matter.

With conventional products, the filtration performance is selected (among other influencing factors such as tobacco blend, ventilation, etc.) in order to adjust the "delivery" of the cigarette (content of smoke ingredients in mainstream smoke). In many markets, “delivery” is limited by law. Below the legal limit, “delivery” can be adjusted to consumer preferences.

With HNB products, there is much less condensed matter with negative health relevance in the aerosol than with conventional products. However, since desired substances, such as flavor-forming substances and nicotine, are also present in the condensate, the aim here is to choose the lowest possible filtration performance, which, however, must not fall to zero.

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

However, with HNB products, the draw resistance contribution of the mouth-side filter (mouthpiece) tends to be as low as possible, since the other components of the HBN device, in particular the heated tobacco portion and the device, already have a high draw resistance contribution. A low tensile resistance of the filter (mouthpiece) leads to degrees of freedom for the other components of the HBN device, which is desirable.

However, the pulling resistance and the filtration performance are closely linked. Both can be reduced in several ways, but this often negatively affects other parameters.

For example, draft 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, the processability becomes problematic. Also A shorter filter leads to a shorter cooling distance, which is problematic for the heat balance.

Alternatively or additionally, the tensile resistance and the filtration performance can be reduced by reducing the fiber weight in the filter material per volume fraction and/or the total denier. However, this has the disadvantage that the Filtrona hardness decreases and under certain circumstances the minimum hardness can no longer be achieved.

Alternatively or additionally, the pulling resistance and the filtration performance can be reduced by increasing the filament titer. With a constant filter diameter and a given fiber weight per unit volume, the filtration performance and tensile resistance are reduced as the filament titer increases, which is desirable for HNB products compared to conventional products. Since, as stated above, the Filtrona hardness hardly depends on the filament titer, the hardness is not negatively affected.

With regard to the target parameter “Optics”, it should be noted that the consumer prefers a mouthpiece with a flat, white cross-sectional area on the mouth side. However, there are also products that are shaped into a tube on the mouth side.

Regarding the smoke temperature, it should be noted that the smoke temperature is not a problem with today's conventional products. However, with commercially available HNB products, the smoking temperature is noticeably high and, for some consumers, uncomfortably high. In addition, commercially available HNB products require cooling to cool the evaporated components so that an aerosol is formed from the gaseous components.

For commercially available HNB products, the distance from the heating element to the end of the mouth of the HNB article is certainly the most important parameter for cooling the aerosol. For example, it is known to connect a so-called cooling element downstream of the tobacco portion and the support element. The cooling element can be designed in the form of a crimped polylactide film or in the form of a cardboard tube, whereby - in addition to cooling - this element downstream of the tobacco portion and the support element also has the function of a placeholder that provides mechanical stability.

Ultimately, mouthpiece materials must meet the target parameter of cost-effectiveness. There is a particular need for suitable mouthpiece materials that can be produced with the lowest possible use of materials and with the lowest possible process costs.

Although conventional cigarette filters, which are usually made of cellulose acetate filaments, ensure optimal filtration of smoke ingredients, these filter materials can often only be used to a limited extent in other applications, in particular in HNB products or e-cigarettes, since in these applications the filter materials or materials for the Mouthpiece must take on other functions.

HNB products, as well as conventional smoking products, generally have the disadvantage that the inhaled aerosol is absorbed by the user at a high temperature. This is sometimes unpleasant for the user. In the case of HNB products in particular, the mouthpiece materials have the task of cooling the aerosol with the lowest possible filtration performance.

But even with classic cigarettes, especially with 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 materials for the mouthpiece must have a - in comparison to filter materials for King size cigarettes - offer reduced filtration performance and increased cooling and improved haptic properties (firm but not too hard grip). Naturally, there is less smoke/flavor when burned than with a king-size cigarette. In order not to further reduce the taste, a low filtration performance is aimed for. If the amount of filter material is simply reduced for this purpose, the filter hardness will eventually become insufficient.

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 not desirable.

For both HNB products and ultra-slim cigarettes, it has been proposed to achieve the desired reduced filtration performance in terms of condensable components such as tar, as well as sufficient filter hardness, by increasing the film titer while maintaining the overall titer. This approach However, it has the disadvantage that such fiber materials with high filament titer have economic disadvantages on the conventionally used spinning machines. In the production of conventional filter tow, a solution of approximately 30% cellulose 2,5-acetate in acetone is pressed through spinnerets, the acetone evaporates in a spinning shaft by blowing with heated air, a variety of filaments (1,000 to 35,000) gathered into a band and then curled into a bush chamber. In the case of higher filament titers, a larger amount of solvent must be evaporated per filament, which takes more time due to the larger ratio of filament cross-sectional area to filament surface and results in slower spinning speeds.

Based on this problem, the present invention is based on the object of specifying a material which is suitable for a wide range of applications in tobacco products.

In particular, the present invention is based on the object of specifying a filter material with low tensile resistance and low filtration performance, with the filter material being able to achieve a sufficiently high Filtrona hardness that is as constant as possible when used in smoking products, and yet the filter material can be produced particularly economically.

In addition, the filter material should be suitable for producing a filter with a uniform, white and flat mouth-side end face.

In this context, it is also desirable for the filter material to have a selective filtration effect on phenols.

The filter material should be particularly suitable for reliably cooling a heated particle-laden gas, so that the temperature of the gas, aerosol or vapor absorbed by the user from a smoking article can be reduced.

Furthermore, the material should be suitable so that when the material is used as a filter material for, in particular, slim or ultra-slim cigarettes, an adjustable and, in particular, reduced draw resistance compared to king-size filters can be achieved.

These tasks are solved by the respective subject matter of independent claims 1, 8 and 12.

Accordingly, the present teaching relates in particular to a material for forming a mouthpiece for smoking products, the material having a filling material which is based on cellulose acetate filaments, which are at least partially designed as hollow-shaped cellulose acetate filaments. The filling material, which is partly designed as hollow-shaped cellulose acetate filaments, has a lower density and a higher filling value than classic cellulose acetate filaments, which are not hollow-shaped and which are usually used in cigarette filters. By providing such a filling material, the performance that can be achieved with the mouthpiece and the range of applications can be significantly increased.

The term “hollow-shaped fiber” used here is to be understood in particular as meaning a preferably cylindrical fiber which has one or more continuous cavities in cross section. The hollow-shaped fibers are preferably at least partially crimped. However, the invention is not limited to crimped hollow fibers, but also relates to non-crimped fibers and their use.

According to embodiment variants of the present invention, the hollow-shaped fibers are at least partially designed as multi-lumen hollow fibers. Compared to single-lumen hollow fibers, multi-lumen hollow fibers are significantly more resistant to kinks, which means that particularly high Filtrona hardness levels can be achieved without increased material compaction.

The term “Filtrona hardness” used herein means the filter hardness determined according to the Filtrona principle. With this principle, the filter hardness is determined by pressing a cylindrical rod with a diameter of 12 mm with its flat face 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 touch results in the percentage of Filtrona hardness.

According to preferred embodiments of the present invention, the hollow-shaped cellulose acetate filaments at least partially have a trilobal, i.e. three-armed star-shaped cross-sectional shape. Such a cross-sectional shape is suitable if the cellulose acetate filaments should have the largest possible specific surface area, for example to enable high filtration capacity while at the same time economical use of raw materials. Alternatively, it is possible to obtain the desired large specific surface area by a bundle of extremely fine filaments of circular cross-section. However, other cross-sectional shapes are also conceivable for the hollow-shaped cellulose acetate filaments, such as a square cross-sectional shape.

The filter and/or filling material can be produced inexpensively and can be processed alone or with classic cellulose acetate filaments that are not hollow-shaped to form a filter rod with suitable tensile resistance and optimized filter properties.

Because the filter and/or filling material has a filling material which is based on cellulose acetate filaments, which are at least partially designed as hollow-shaped cellulose acetate filaments, a low tensile resistance and a low filtration performance can be achieved, since the filaments of the filter are at least partially designed as hollow-shaped cellulose acetate filaments - and/or filling material have a low external surface area based on the total fiber volume. It is preferred that the filaments of the filter and/or filling material, which are at least partially designed as hollow cellulose acetate filaments, have a cross section that is as round as possible. In this context, it was surprisingly found that particularly high Filtrona hardnesses can be achieved with the filter and/or filling material due to the filaments being at least partially designed as hollow cellulose acetate filaments. In fact, it has been found that filters 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.

Since it is based on cellulose acetate filaments, the filter and/or filling material is suitable for producing a filter with a uniform, white and flat mouth-side end face, whereby a selective filtration effect on phenols can also be achieved.

By using a filter and/or filling material based on cellulose acetate filaments, on the one hand, filter rods can be produced, especially for cigarettes, which have demonstrably outstanding properties regarding specific retention phenomena with regard to the discussion regarding smoking and health. A filter made of cellulose acetate filters nitrosamines and phenols, which are harmful to health, much more efficiently than condensate and nicotine. In addition, the smoke taste of today's common tobacco blends, such as "American Blend", "German Blend" and "Virginia" in combination with a filter rod made of cellulose acetate, is judged by the smoker to be the most pleasant. Another advantage of a filter rod made of cellulose acetate that should not be underestimated is the optical homogeneity of the cut surfaces of the filter.

Because the filter and/or filling material is at least partially formed from hollow-shaped cellulose acetate filaments, which serve as filling material, the tensile resistance and filtration performance of filter rods made from the material according to the invention can be varied over a wide range.

In particular, it has been shown that a filter material which at least partially consists of hollow-shaped cellulose acetate filaments has an improved thermal cooling effect. It was found that by using hollow-shaped cellulose acetate filaments as filling material, a very low filter effect, ie retention effect, for the suspended matter and gases to be removed can still be achieved. It is assumed that this effect is achieved by the hollow-shaped cellulose acetate filaments changing the surface or the flow of the gas or air to be cleaned in such a way that any suspended matter present in the gas or air is hardly retained. Another reason could be that a different, particularly advantageous surface structure of the filter material can be achieved by using hollow-shaped cellulose acetate filaments.

The filter and/or filling material also has the advantage that it enables particularly adjustable cooling of a heated particle-laden gas (in particular aerosol), so that the temperature of the gas, aerosol or vapor absorbed by the user of a smoking article or HNB product can be controlled in a targeted manner can be reduced. By varying the proportion of hollow-shaped cellulose acetate filaments in the filter and/or filling material, the desired cooling effect can be adapted to the specific application. It is also important to mention that the hollow-shaped cellulose acetate filaments (= hollow fibers) in the filter and/or filling material are essentially flowed around and flow through less. From geometric considerations it can be seen 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) means that the path of least resistance is chosen (i.e. it flows between the filaments and not through each individual filament.

In other words, in the filter and/or filling material the effective filtration surface is in no way maximized, since the hollow-shaped cellulose acetate filaments in the filter and/or filling material are not flowed through.

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

In particular, it should be mentioned in this context that the hollow-shaped cellulose acetate filaments designed as hollow fibers do not have to be hollow throughout, but can also be partially closed by kinks. They can also deviate from an ideal circular shape.

In embodiments it is provided that the hollow-shaped cellulose acetate filaments of the filter and/or filling material serve on the one hand as a carrier material and on the other hand as a cooling material. Because the hollow-shaped cellulose acetate filaments also serve as a carrier material, they are particularly compact Mouthpieces can be realized where the dimensions of the smoking article do not have to be increased.

It is conceivable, for example, that the filter and/or filling material has adjacent areas with hollow-shaped cellulose acetate filaments and non-hollow-shaped cellulose acetate filaments in the longitudinal direction of the mouthpiece. A mixture of hollow and non-hollow cellulose acetate filaments would also be conceivable. Alternatively or additionally, the hollow and non-hollow cellulose acetate filaments may be arranged in layers and then folded. In this way, the largest possible area of the hollow cellulose acetate filaments serving as cooling material is possible, whereby the particle-laden gas can be cooled better.

The filter and/or filling material can be introduced into the smoking article in such a way that, in particular, the hollow-shaped cellulose acetate filaments are arranged essentially along the flow direction of the particle-laden gas or the aerosol. In this way, it can be achieved that the filter and/or filling material only causes a reduced pressure loss when the user sucks on the mouthpiece, so that the user does not perceive the suction as strenuous or unpleasant. By varying the orientation of the hollow-shaped cellulose acetate filaments with respect to the flow direction of the particle-laden gas or aerosol, the tensile resistance of the filter and/or filling material can be varied over a wide range and adapted to the respective application.

By varying the proportion of hollow and non-hollow cellulose acetate filaments in the filter and/or filling material and/or by adjusting the orientation of the hollow and non-hollow cellulose acetate filaments with respect to the flow direction of the particle-laden gas or aerosol in the filter and / or filling material is varied, not only the cooling and filtration performance, but also the tensile resistance of the filter and / or filling material can be adjusted.

Alternatively, it is provided that the filter and/or filling material consists only of hollow-shaped cellulose acetate filaments. The filter and/or filling material then has optimal cooling performance with reduced filtration performance.

A further embodiment of the filter and/or filling material provides that the filter and/or filling material is arranged as a separate segment in front of the mouthpiece in the flow direction of the particle-laden gas or aerosol. The separate segment can have a variety of shapes. A preferred cylindrical shape is described as an example, to which the invention should not be limited. Conventional smoking articles are usually essentially cylindrical. The separate segment can also be arranged in front of a possible filter in the flow direction of the particle-laden gas. The filter and/or filling material that serves as a cooling device and is designed as a separate segment can, for example, consist entirely of hollow-shaped cellulose acetate filaments.

It is also conceivable that the separate segment has a covering, for example made of paper or a type of housing, so that the hollow-shaped cellulose acetate filaments serving as cooling material can be encapsulated. The casing or housing has an inlet opening and an outlet opening for the particle-laden gas or aerosol, through which it flows due to the user's suction through the mouthpiece. The hollow-shaped cellulose acetate filaments serving as cooling material can, for example, also optionally be attachable in or on the smoking article in encapsulated form. In this way, a user has the option of only cooling the particle-laden gas if they consider it necessary.

As already stated, in particular the tensile resistance of a filter rod formed from the filter material can be varied over a significantly larger range by varying the proportion of hollow-shaped cellulose acetate filaments in the filter material.

In summary, it should be noted that by using a filter material which consists at least partially of hollow-shaped cellulose acetate filaments, the tensile resistance and the filtration performance can be adapted to the respective requirements over a wide range, and in fact significantly more flexibly than with conventional filter materials based on cellulose acetate filaments case is. In addition, a cooling effect can be adjusted variably.

In particular, the present invention allows mouthpieces or filters to be formed from cellulose acetate, which is normally in the form of a strand of essentially longitudinally directed endless filaments, the endless filaments preferably being crimped so that short areas of the individual filaments are irregularly inserted are arranged in non-parallel, converging and diverging directions compared to the predominantly longitudinal direction of the strand.

In a possible embodiment of the filter material, the surface structure of the filter material can be varied by using, in particular, crimped cellulose acetate filaments. The crimp index of the cellulose acetate filaments is preferably between 10% and 60%, and in particular between 20% and 50%.

The curl index I _x is a measure of the intensity of the curl. The curl index of a filter tow is determined by a tensile test (force/elongation relationship). It is defined as the ratio of the stretched length L ₂ under test load minus the initial length to the initial length under preload L ₁ : $${\mathrm{I}}_{\mathrm{x}}=\left({\mathrm{L}}_2-{\mathrm{L}}_1\right)/{\mathrm{L}}_1\ast 100\%$$

The test load is 25 N and the preload is 2.5 N. The clamping length is 250 mm. The crimp index is determined in a tensile test with a constant stretching rate of 300 mm/min on a G02 device from Borgwaldt GmbH, Hamburg. 10 individual measurements are recorded per measurement. The test is carried out under standard climate: 20 °C and 60% relative humidity.

The filter material is preferably in the form of a filter tow consisting of endless, stufferbox-crimped cellulose acetate filaments, and in particular cellulose 2,5-acetate filaments. To produce the filter tow, a solution of approximately 30% cellulose 2,5-acetate in acetone is pressed through special spinnerets, the acetone evaporates in a spinning shaft by blowing it with heated air, producing a large number of filaments (1,000 to 35,000). summarized in a band and then curled into a bush chamber. The product is then dried, poured into storage containers and finally pressed into bales weighing 300 to 600 kg.

To spin the spinning solution, spinnerets are used, which are designed to spin hollow-shaped cellulose acetate filaments and/or cellulose acetate staple fibers.

After the filter tow bales have been transported to the filter or cigarette manufacturer, the filter tow is removed from the bale and placed on a filter rod machine, such as in the publication US 5,460,590 A described, processed into filter rods. The filter tow is stretched in a stretching device, provided with an additive used to bond the filaments and then, after forming a three-dimensional fuse, it is introduced into the format part with the help of an inlet funnel, where it is compressed transversely axially, covered with paper and to the final length of the filter rods cut.

The additive applied to bond the filaments can be a high-boiling solvent for cellulose acetate, such as glycerol triacetate (triacetin), which briefly dissolves the surface of the filaments after its application. Wherever two filaments happen to touch each other, a solid bond occurs some time later because the excess additive migrates into the fiber surface, causing the previously liquid drop of solution to solidify. After a storage period of less than an hour, due to the previously mentioned migration of the hardening agent, mechanically strong, three-dimensionally networked filter rods are obtained, which are also referred to as "space filters", and which have a low packing density of usually 20 mg/ml to 90 mg / ml, preferably 30 to 70 mg/ml and more preferably 40 to 60 mg/ml. Due to their hardness, these filter rods can be processed at high speeds without any difficulty on modern cigarette machines.

Studies have shown that by using hollow-shaped cellulose acetate filaments in the filter material, the filtration performance of spatial filters can be reduced and the cooling performance can be increased while maintaining the specifications such as length, diameter, tensile resistance and filament titer.

By increasing the proportion of hollow fibers (hollow-shaped cellulose acetate filaments) in the filter material, the tensile resistance can be as low as required despite increasing the cooling capacity and reducing the filter capacity Range can be maintained without causing an increase in the filament titer.

In particular, according to implementations of the filter material, it is provided that the proportion of hollow-shaped (hollow) cellulose acetate filaments in the filter material is between 20 to 100% and preferably between 40 to 100% and even more preferably - depending on the application - between 70 to 100%.

According to the invention, the hollow content in the filter material is preferably 25 to 90% and preferably 50 to 80%. This hollow portion makes a decisive contribution to the filtration performance on the one hand and to the reduction of tensile resistance on the other, which can only be achieved due to a corresponding proportion of hollow fibers in the filter material, but not with closed filaments. The hollow portion corresponds to the ratio of the “hollow” area of the filter material to the “total” cross-sectional area of the fibers.

In this context, it should be mentioned that the filter material according to the invention is particularly characterized by the fact that the filament diameter of the cellulose acetate filaments is significantly larger than the filament diameter of other (synthetic) hollow fibers, the filament diameter of which is in the range between 10 and 30 μm. In contrast to this, the filament diameter of the hollow cellulose acetate filaments is in the range between 30 to 150 μm (outer diameter), and preferably between 50 to 120 μm (outer diameter), and according to the invention between 60 to 100 μm (outer diameter). In this way, the hollow portion can be increased and thus the specific filtration performance of the filter and/or filling material according to the invention can be significantly reduced, while at the same time the cooling performance of the filter and/or filling material according to the invention is increased.

The invention further relates to a cigarette filter made of a filter material of the aforementioned type.

To make a filter, in non-limiting embodiments, either a thermoplastic cellulose ester fiber material or, in the case of a non-thermoplastic cellulose ester, a water-soluble adhesive may be used. For the first case one thermoplastic cellulose ester fiber material, two cases can be distinguished. In the first case, the fiber material is made from a naturally thermoplastic cellulose ester, such as cellulose acetobutyrate. In this, the filter tow can be processed into filters according to the invention without further measures. In the case of a non-thermoplastic starting polymer, such as cellulose 2,5-acetate, it must be thermoplasticized by adding a suitable plasticizer.

To produce the filter, a filter tow is pulled off a bale, spread out pneumatically and stretched using the usual process for spatial filters.

Within the scope of the teaching according to the invention, the acetate weight can be a maximum of 5 mg per mm of filter length and at least about 2 mg per mm of filter length and is in particular about 3 to 4 mg per mm of filter length. If the maximum value of 5 mg per mm of filter length is exceeded, then such a product is not sufficiently economical. Preferably, a minimum value of approximately 2 mg per mm of filter length is maintained. If this value is not reached, the desired hardness of the cigarette filter of at least 88% can no longer be maintained according to the state of the art.

Within the scope of the inventive teaching, the tensile resistance can be a maximum of 2 mm daPa per mm filter length and at least approximately 0.1 daPa per mm filter length and is in particular 0.2 daPa to 1 daPa per mm filter length. A tensile resistance of 0.3 daPa to 0.7 daPa per mm of filter length is particularly preferred. Preferably, a minimum value of 0.3 daPa per mm of filter length is maintained. If this value is not reached, then the desired hardness of the filter of at least 88% can no longer be maintained according to the current state of the art.

• Gemäß einem ersten Aspekt betrifft die vorliegende Lehre ein Filter- und/oder Füllmaterial für Mundstücke zur Verwendung mit Rauchwaren oder HNB-Produkten, wobei das Filter- und/oder Füllmaterial auf Celluloseacetatfilamenten basiert, welche zumindest teilweise als hohlförmige und/oder rohrförmige Celluloseacetatfilamente ausgebildet sind.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials weisen die Celluloseacetatfilamente hohlförmige und insbesondere gekräuselte endlos-Celluloseacetatfilamente und/oder hohlförmige und insbesondere gekräuselte und geschnittene Endlos- Celluloseacetatfilamente auf.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials liegt der Kräuselindex der Celluloseacetatfilamente zwischen 10 % und 60 %, insbesondere zwischen 20 % und 50 %.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials sind die Celluloseacetatfilamente aus einem thermoplastischen Cellulosematerial gebildet, wobei die Celluloseacetatfilamente, sofern ein Weichmacher einbezogen wird, diesen gleichmäßig verteilt enthalten, und/oder wobei auf der Oberfläche der Celluloseacetatfilamente ein wasserlösliches Verklebungsmittel vorliegt.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials liegt im Falle des Einsatzes eines Weichmachers der Weichmachergehalt zwischen 1 und 40 %.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials ist im Falle des Einsatzes eines Weichmachers dieser Triacetin, Triethylenglykoldiacetat und/oder Zitronensäurediethylester.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials weisen die Celluloseacetatfilamente eine Feinheit zwischen 5 bis 30 Denier, bevorzugt zwischen 10 bis 25 Denier und noch bevorzugt zwischen 15 bis 20 Denier auf.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials beträgt der Gesamttiter des Filter- und/oder Füllmaterials zwischen 4.000 und 40.000 Denier und vorzugsweise zwischen 6.000 und 30.000 Denier.
• Gemäß der Erfindung beträgt - bezogen auf einen Schnitt orthogonal zu den Fasern des Filter- und/oder Füllmaterials - der Hohlanteil in dem Filter- und/oder Füllmaterial 25 % bis 90 % und vorzugsweise 50 % bis 80 %.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials liegt der Filamentdurchmesser der Celluloseacetatfilamente in einem Bereich zwischen 30 bis 150 µm (Außendurchmesser), und vorzugsweise in einem Bereich zwischen 50 bis 120 µm (Außendurchmesser), und erfindungsgemäß in einem Bereich zwischen 60 bis 100 µm (Außendurchmesser).
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials liegt der Masseanteil an hohlförmigen Celluloseacetatfilamenten bei 20 bis 100 % vorzugsweise bei 50 bis 100 % und noch bevorzugter bei 70 bis 100 %.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials stehen die hohlförmigen Celluloseacetatfilamente mit gegenseitigen Abständen in ungeregelter Anordnung zueinander, wobei die Celluloseacetatfilamente vernetzt sind, und wobei die verbindenden Celluloseacetatfilamente gegenseitig verschlauft und/oder verhakt sind.
• Gemäß einer Ausführungsvariante des Filter- und/oder Füllmaterials ist ferner ein Binder, insbesondere ein organischer oder anorganischer Binder vorgesehen zum Zusammenhalten der Celluloseacetatfilamente.
• Gemäß einem weiteren Aspekt betrifft die vorliegende Erfindung ein Mundstück zur Verwendung mit Rauchwaren oder HNB-Produkten, wobei das Mundstück ein Filter- und/oder Füllmaterial der zuvor genannten, erfindungsgemäßen Art aufweist.
• Gemäß einem weiteren Aspekt betrifft die vorliegende Erfindung einen Zigarettenfilter oder ein Zigarettenfilterelement, welcher bzw. welches ein Filter- und/oder Füllmaterial der zuvor genannten, erfindungsgemäßen Art aufweist.
• Gemäß Ausführungsvarianten des Zigarettenfilters bzw. des Zigarettenfilterelements ist mindestens ein Merkmal der nachfolgend genannten Merkmale realisiert:
  • ▪ die Faserdichte des Filter- und/oder Füllmaterials beträgt zwischen 10 bis 70 kg pro m³ und vorzugsweise zwischen 20 bis 70 kg pro m³ und noch bevorzugter zwischen 40 bis 60 kg pro m³;
  • ▪ der Zigarettenfilter oder das Zigarettenfilterelement weist eine Filtronahärte von mindestens 88 % und vorzugsweise eine Filtronahärte von 88 % bis 95 % und noch bevorzugter eine Filtronahärte von 90% bis 93 % auf;
  • ▪ der Zigarettenfilter oder das Zigarettenfilterelement weist einen Zugwiderstand von mindestens 0,1 daPa pro mm Filterlänge und vorzugsweise einen Zugwiderstand von 0,2 daPa bis 1,0 daPa pro mm Filterlänge und noch bevorzugter einen Zugwiderstand von 0,3 daPa bis 0,7 daPa pro mm Filterlänge auf;
  • ▪ das Filter- und/oder Füllmaterial weist einen Weichmacher auf, wobei der Weichmachergehalt zwischen 1 % bis 40 % liegt.
• Gemäß Ausführungsvarianten des Zigarettenfilters bzw. des Zigarettenfilterelements ist ferner ein insbesondere kapselförmiges oder kapselartiges Geschmacksabgabeelement in dem Filter- und/oder Füllmaterial eingebettet.
• Gemäß Ausführungsvarianten des Zigarettenfilters bzw. des Zigarettenfilterelements weist der Zigarettenfilter bzw. das Zigarettenfilterelement zusätzlich zu den hohlförmigen Celluloseacetatfilamenten massive Celluloseacetatfilamente auf.
• Gemäß einem weiteren Aspekt betrifft die vorliegende Lehre die Verwendung des erfindungsgemäßen Filter- und/oder Füllmaterials in Rauchwaren oder in HNB-Produkten.
• Gemäß einem weiteren Aspekt betrifft die vorliegende Erfindung ein Verfahren zur Herstellung eines Filter- und/oder Füllmaterials für Mundstücke zur Verwendung mit Rauchwaren oder HNB-Produkten, wobei das Filter- und/oder Füllmaterial vorzugsweise aus Celluloseacetatfilamenten und/oder Celluloseacetatspinnfasern besteht, wobei eine Lösung von Celluloseacetat mit einer Acetylzahl von mindestens 53 % in Aceton durch eine Spinndüse mit mehreren Öffnungen gepresst wird, und wobei anschließend gegebenenfalls die Celluloseacetatfilamente zu Celluloseacetatspinnfasern zerschnitten werden und wobei eine Vielzahl der so erhaltenen Celluloseacetatfilamente und/oder Celluloseacetatspinnfasern zu einem Filtertow zusammengefasst werden, welches gegebenenfalls gekräuselt wird, wobei die Spinndüse, durch welche die Lösung von Celluloseacetat gepresst wird, derart ausgestaltet ist, dass hohlförmige Celluloseacetatfilamente ersponnen werden.

Some key aspects are summarized below:

• According to a first aspect, the present teaching relates to a filter and/or filling material for mouthpieces for use with smoking products or HNB products, wherein the filter and/or filling material is based on cellulose acetate filaments, which are at least partially formed as hollow-shaped and/or tubular cellulose acetate filaments .
• According to an embodiment variant of the filter and/or filling material, the cellulose acetate filaments have hollow-shaped and in particular crimped endless cellulose acetate filaments and/or hollow-shaped and in particular crimped and cut continuous cellulose acetate filaments.
• According to an embodiment variant of the filter and/or filling material, the crimp index of the cellulose acetate filaments is between 10% and 60%, in particular between 20% and 50%.
• According to an embodiment variant of the filter and/or filling material, the cellulose acetate filaments are formed from a thermoplastic cellulose material, whereby the cellulose acetate filaments, if a plasticizer is included, contain this evenly distributed, and/or where a water-soluble adhesive is present on the surface of the cellulose acetate filaments.
• According to an embodiment variant of the filter and/or filling material, if a plasticizer is used, the plasticizer content is between 1 and 40%.
• According to an embodiment variant of the filter and/or filling material, if a plasticizer is used, this is triacetin, triethylene glycol diacetate and/or diethyl citric acid.
• According to an embodiment variant of the filter and/or filling material, the cellulose acetate filaments have a fineness between 5 to 30 denier, preferably between 10 to 25 denier and even preferably between 15 to 20 denier.
• According to an embodiment variant of the filter and/or filling material, the total titer of the filter and/or filling material is between 4,000 and 40,000 denier and preferably between 6,000 and 30,000 denier.
• According to the invention - based on a section orthogonal to the fibers of the filter and / or filling material - the hollow content in the filter and / or filling material is 25% to 90% and preferably 50% to 80%.
• According to an embodiment variant of the filter and/or filling material, the filament diameter of the cellulose acetate filaments is in a range between 30 to 150 µm (outer diameter), and preferably in a range between 50 to 120 µm (outer diameter), and according to the invention in a range between 60 to 100 µm (outer diameter).
• According to an embodiment variant of the filter and/or filling material, the mass fraction of hollow-shaped cellulose acetate filaments is 20 to 100%, preferably 50 to 100% and even more preferably 70 to 100%.
• According to an embodiment variant of the filter and/or filling material, the hollow-shaped cellulose acetate filaments are arranged at mutual distances in an irregular arrangement from one another, the cellulose acetate filaments being cross-linked, and the connecting cellulose acetate filaments being intertwined and/or intertwined with one another.
• According to an embodiment variant of the filter and/or filling material, a binder, in particular an organic or inorganic binder, is also provided to hold the cellulose acetate filaments together.
• According to a further aspect, the present invention relates to a mouthpiece for use with smoking products or HNB products, the mouthpiece having a filter and/or filling material of the aforementioned type according to the invention.
• According to a further aspect, the present invention relates to a cigarette filter or a cigarette filter element, which has a filter and/or filling material of the aforementioned type according to the invention.
• According to embodiment variants of the cigarette filter or the cigarette filter element, at least one feature of the following features is implemented:
  • ▪ the fiber density of the filter and/or filling material is between 10 to 70 kg per m ³ and preferably between 20 to 70 kg per m ³ and even more preferably between 40 to 60 kg per m ³ ;
  • ▪ the cigarette filter or the cigarette filter element has a Filtrona hardness of at least 88% and preferably a Filtrona hardness of 88% to 95% and more preferably a Filtrona hardness of 90% to 93%;
  • ▪ the cigarette filter or the cigarette filter element has a tensile resistance of at least 0.1 daPa per mm filter length and preferably a tensile resistance of 0.2 daPa to 1.0 daPa per mm filter length and more preferably a tensile resistance of 0.3 daPa to 0.7 daPa per mm filter length;
  • ▪ The filter and/or filling material has a plasticizer, with the plasticizer content being between 1% and 40%.
• According to embodiment variants of the cigarette filter or the cigarette filter element, a particularly capsule-shaped or capsule-like flavor release element is also embedded in the filter and/or filling material.
• According to embodiment variants of the cigarette filter or the cigarette filter element, the cigarette filter or the cigarette filter element has solid cellulose acetate filaments in addition to the hollow-shaped cellulose acetate filaments.
• According to a further aspect, the present teaching relates to the use of the filter and/or filling material according to the invention in smoking products or in HNB products.
• According to a further aspect, the present invention relates to a method for producing a filter and/or filling material for mouthpieces for use with smoking products or HNB products, wherein the filter and/or filling material preferably consists of cellulose acetate filaments and/or cellulose acetate staple fibers, wherein a solution of cellulose acetate with an acetyl number of at least 53% in acetone is pressed through a spinneret with several openings, and the cellulose acetate filaments are then optionally cut into cellulose acetate staple fibers and a large number of the cellulose acetate filaments and / or cellulose acetate staple fibers thus obtained are combined into a filter tow, which optionally is crimped, the spinneret through which the solution of cellulose acetate is pressed being designed such that hollow-shaped cellulose acetate filaments are spun.

Claims (15)

1. A method for manufacturing a filter material and/or filler material for mouthpieces for use in smoking products or HNB products consisting of cellulose acetate filaments and/or cellulose acetate staple fibers, wherein a solution of cellulose acetate having an acetyl value of at least 53% in acetone is pressed through a spinneret having multiple openings, and wherein the cellulose acetate filaments are then cut into cellulose acetate staple fibers as needed and wherein a multitude of the cellulose acetate filaments and/or cellulose acetate staple fibers thus obtained are gathered into a filter tow which is crimped as applicable, wherein the spinneret through which the solution of cellulose acetate is pressed is designed such that hollow cellulose acetate filaments are spun, wherein - in relation to a cut orthogonal to the fibers of the filter material and/or filler material - the hollow portion in the filter material and/or filler material amounts to 25% to 90% and preferably 50% to 80%, and wherein the filament diameter of the cellulose acetate filaments is in a range of between 60 to 100 µm.
2. The method according to claim 1,
   wherein the crimp index of the cellulose acetate filaments is between 10% and 60%, particularly between 20% and 50%.
3. The method according to claim 1 or 2,

   wherein the cellulose acetate filaments contain an evenly distributed plasticizer; and/or

   wherein a water-soluble adhesive is present on the surface of the cellulose acetate filaments.
4. The method according to one of claims 1 to 3,

   wherein the cellulose acetate filaments and/or cellulose acetate staple fibers comprise a plasticizer, and wherein the plasticizer content is between 1% and 40 %; and/or

   wherein the cellulose acetate filaments and/or cellulose acetate staple fibers comprise a plasticizer, and wherein the plasticizer is triacetin, triethylene glycol diacetate and/or citric acid diethyl ester.
5. The method according to one of claims 1 to 4,

   wherein the cellulose acetate filaments have a fineness of between 5 and 30 denier, preferentially between 10 and 25 denier, and more preferentially between 15 and 20 denier; and/or

   wherein the total titer of the filter material and/or filler material is between 4000 and 40000 denier and preferably between 6000 and 30000 denier.
6. The method according to one of claims 1 to 5,
   wherein the mass fraction of hollow cellulose acetate filaments is 20% to 100%, preferably 50% to 100% and further preferentially 70% to 100%.
7. The method according to one of claims 1 to 6,

   wherein the hollow cellulose acetate filaments are mutually distanced from one another in an irregular arrangement, and wherein the cellulose acetate filaments are crosslinked, whereby the connecting cellulose acetate filaments are entwined and/or entangled with one another; and/or

   wherein a binder, particularly an organic or inorganic binder, is further provided for binding the cellulose acetate filaments.
8. A mouthpiece for use with smoking or HNB products, wherein the mouthpiece comprises filter material and/or filler material produced in accordance with a method according to claims 1 to 7.
9. The mouthpiece according to claim 8,

   wherein the fiber density of the filter material and/or filler material amounts to between 10 and 70 kg per m³, preferably to between 20 to 70 kg per m³, and further preferentially to between 40 to 60 kg per m³; and/or

   wherein the cigarette filter or cigarette filter element has a Filtrona hardness of at least 88%, preferably a Filtrona hardness of 88% to 95%, and further preferentially a Filtrona hardness of 90% to 93%; and/or

   wherein the cigarette filter or cigarette filter element has a draw resistance of at least 0.1 daPa per mm of filter length, preferably a draw resistance of 0.2 daPa to 1.0 daPa per mm of filter length, and further preferentially a draw resistance of 0.3 daPa to 0.7 daPa per mm of filter length.
10. The mouthpiece according to claim 8 or 9,
    wherein an in particular capsule-shaped or capsule-like flavor release element is further incorporated into the filter material and/or filler material.
11. The mouthpiece according to one of claims 8 to 10,
    wherein the filter material and/or filler material also comprises solid cellulose acetate filaments in addition to the hollow cellulose acetate filaments.
12. A cigarette filter or cigarette filter element comprising a filter material and/or filler material produced in accordance with a method according to claims 1 to 7.
13. The cigarette filter or cigarette filter element according to claim 12,

    wherein the fiber density of the filter material and/or filler material amounts to between 10 and 70 kg per m³, preferably to between 20 to 70 kg per m³, and further preferentially to between 40 to 60 kg per m³; and/or

    wherein the cigarette filter or the cigarette filter element has a Filtrona hardness of at least 88%, preferably a Filtrona hardness of 88% to 95%, and further preferentially a Filtrona hardness of 90% to 93%; and/or

    wherein the cigarette filter or the cigarette filter element has a draw resistance of at least 0.1 daPa per mm of filter length, preferably a draw resistance of 0.2 daPa to 1.0 daPa per mm of filter length, and further preferentially a draw resistance of 0.3 daPa to 0.7 daPa per mm of filter length.
14. The cigarette filter or cigarette filter element according to claim 12 or 13, wherein an in particular capsule-shaped or capsule-like flavor release element is further incorporated into the filter material and/or filler material.
15. The cigarette filter or cigarette filter element according to one of claims 12 to 14, wherein the cigarette filter or cigarette filter element respectively also comprises solid cellulose acetate filaments in addition to the hollow cellulose acetate filaments.