ES2971668T3 - Procedure for the manufacture of a filter and/or filler material for use with smoking articles or HNB products, cigarette mouthpieces and filter with such a filter and/or filler material - Google Patents

Abstract

The invention relates to a filter material and/or filler material for mouthpieces for use with smoking products or HNB products, the filter material and/or filler material being based on cellulose acetate filaments, at least parts of which are in the form of hollow cellulose acetate filaments. The invention also relates to a mouthpiece for use with smoking products or HNB products, the mouthpiece comprising a filter material and/or filler material of the type according to the invention. The invention also relates to a cigarette filter comprising said filter material and/or filler material, and to a corresponding method for manufacturing a filter material and/or filler material for mouthpieces for use with smoking products or HNB products. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Procedure for the manufacture of a filter and/or filler material for use with smoking articles or HNB products, cigarette mouthpieces and filter with such a filter and/or filler material

The present invention relates to a process for the manufacture of a filter and/or filling material for mouthpieces for use with smoking articles or HNB products, in addition to a mouthpiece for use with smoking articles or HNB products, in wherein the nozzle exhibits a filter and/or filler material, which is manufactured according to such a procedure; and finally to a cigarette filter or cigarette filter element, which exhibits a filter and/or filler material, which is manufactured according to such a process.

According to the present invention, smoking articles refer to classic tobacco products, in particular cigarettes, but also to pipes and marijuana products as well as so-called Heat Without Burning (HNB) products, vaping products and so-called hybrid products.

Depending on the application case, the mouthpieces for the use of smoking articles have different functions. On the one hand, the mouthpieces can serve as a filter device to remove, for example, harmful components from a tobacco smoke stream, such as condensed substances such as tar, as well as particulate matter entrained by the smoke stream. This filter function is used in particular for classic tobacco applications. In this regard, a corresponding mouthpiece can be designed as an integral part of a cigar or a cigarette and can thereby form a "tip" on the cigarette or cigar.

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

The cigarette filter is a mouthpiece formed as an integral part of a cigarette. The cigarette filter should prevent the proportion of harmful substances, such as condensate and gases, into cigarette smoke. Furthermore, through the filter the smoke is perceived by a large proportion of smokers as softer or more pleasant. In a classic filter cigarette, the filter is wrapped by a filter wrapping paper and is connected with the so-called filter wrapping paper to the tobacco cord, where most industrially manufactured cigarettes are supplied with a filter. Those who prepare their own cigarettes can buy these at the tobacco trade.

Numerous types of filter materials are already used, in particular to reduce the content of ingredients in tobacco smoke before it reaches the smoker's respiratory system. In addition to removing harmful components in large quantities, a satisfactory filter must also be effective, without undesirably hindering the passage of air or smoke through the filter, so that stronger suction is necessary. During the use of tobacco smoke filters, the filter material is also not allowed to change the flavor of the tobacco smoke thereby adding to its own flavor.

Another essential factor in the manufacture of a satisfactory filter for tobacco smoke is that its manufacture is not very laborious, thereby not raising the final price of the smoking article in which the filter is used too much.

The present teaching, however, refers less to filter materials for the classical tobacco applications previously described, but in particular to filter and/or filling materials for mouthpieces for the use of smoking articles, where these filter materials and /o padding are appropriate in particular for other functions, other than just a filter function.

In other application cases, a filter function of the nozzles certainly does not have priority. This applies for example to Heat Without Burn products ("HNB products"), which have enjoyed increasing popularity in recent years. In these devices, a portion of processed tobacco is heated but not burned during use by a heat source. In this regard, the volatile components of evaporated tobacco, such as aromatic substances, nicotine, glycerin and water, are carried away by the air that is sucked in by the user through the HNB product. As the released substances cool, an aerosol is formed, which is inhaled by the user.

Common HNB products on the market usually comprise an apparatus consisting of a power supply, which supplies a heating element, and a separate consumable article consisting of a portion of processed tobacco, a supporting element, such as an acetate segment of cellulose made in a tubular manner, a so-called cooling element placed downstream in the direction of flow, for example in the form of a crimped sheet of polylactide, which is rolled into a cylinder with many axial channels, as well as a side-mouth filter . Consumable items are introduced into the device before use, so that the heating element heats the tobacco portion for use of the HNB product.

For example, for a product called IQOS/HEETS from Philip Morris, the tobacco portion is threaded onto a heating sheet in the device. An IQOS/HEETS product means an IQOS device marketed by Philip Morris with the relevant HEETS consumable item. The HEETS consumable item is a Heat Not Burn product, in which only the tobacco is heated, rather than burned.

A competing product, from BAT ("Glo"), heats the tobacco from the outside, where the so-called cooling element is replaced by a tube. Also in these devices, during use, a portion of the processed tobacco is heated but not burned, using a heat source. In this regard, the volatile components of evaporated tobacco, such as aromatic substances, nicotine, glycerin and water, are carried away by the air that is sucked in by the user through the HNB product. As the released substances cool, an aerosol is formed, which is inhaled by the user.

The known consumable items for this application have the disadvantage that their side mouth filters can heat up noticeably, due to their proximity to the heating element, and due to the hot steam that arises during the consumption of the HNB product.

For so-called hybrid products, an aerosol former (propylene glycol, glycerin) is first evaporated, and an aerosol emerges upon cooling. This aerosol is guided through a portion of processed tobacco, and inhaled by the consumer. Also in such applications, the nozzle is particularly suitable for the function of protecting the end on the user's side against heating unpleasant for the user.

Contrary to conventional tobacco products in which the tobacco is burned, for consumable items of HNB products it may be desirable that the element placed downstream of the heated portion of tobacco in the direction of flow, such as cooling elements and side mouth filter , have only a low filter effect with respect to condensed components such as tar, since these smoke components can occur in substantially smaller quantities.

The materials required for the formation of a mouthpiece for smoking articles thus have to be adjusted, and in particular adjustable, to the physical properties of the smoke (temperature, flow profile, etc.) and the chemical composition. In particular, both for conventional cigarette filters and for HNB products there are a number of target parameters, which must be adjusted or satisfied by an appropriate choice and configuration of the mouthpiece materials. This concerns in particular the following target parameters, which will be briefly discussed below:

suction resistance

filtration power

filter bar hardness/Filtrona hardness

aspect

manufacturing profitability

smoke temperature

The hardness of the filter bar is an important objective criterion for cigarette filters. It is usually indicated as the so-called Filtrona hardness. Filtrona hardness is determined by compressing a 12 mm diameter cylindrical bar with its flat front side vertically with a load of 300 g on a horizontally placed filter bar. The ratio of the already compressed diameter to the starting diameter previously determined through the first contact indicates the percentage data of the Filtrona hardness.

It should be emphasized that Filtrona hardness is measured only on a filter, but not on the base (raw) filter material. In particular, Filtrona hardness is influenced by atomized triacetin, especially in cigarette filters.

The minimum limit value of Filtrona hardness is approximately 88% and is oriented towards market requirements. The Filtrona hardness of the cigarette filter can in this case preferably be set to about 88% to 95%, in particular about 90% to 93%.

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

Occasionally, a high Filtrona hardness is also achieved by using a thicker filter covering paper or a thicker filter wrapping paper. A wrapping paper is a paper with which several filter elements are attached to each other, or a filter element is attached to the tobacco rope. Increasing Filtrona hardness by using a thicker filter cover paper or a thicker wrapping paper, however, has economic disadvantages, since higher costs are expected with this approach.

In connection with Filtrona hardness is the so-called "hot collapse", in which the hardness of the filter decreases while smoking. This can then occur in particular when in a classic cigarette, during one of the last draws the filter heats up in the presence of moisture. This undesired effect can also occur with HNB products.

In addition to a high Filtrona hardness that is as constant as possible during the use of a smoking article, the mouthpiece material should also show a determined or predetermined filtration power. The filtration power with respect to condensed matter (droplets, particles), also known as condensate or tar, is of interest in conventional tobacco products as well as HNB products, since in the condensed matter there is a multiplicity of substances with negative relevance for the health.

For conventional products (apart from other influencing factors such as tobacco blending, ventilation, etc.) the filtration power is chosen to adjust the "delivery" of the cigarette (content of smoke ingredients in the mainstream smoke). "Delivery" is limited in many markets upwards by legal determination. Below the legal limit, "delivery" can be adjusted to consumer preferences. dog

For HNB products, much less condensed matter with negative health relevance is found in the aerosol compared to conventional products. Since even more desirable substances, such as flavor-forming substances and nicotine, are present in the condensate, the aim in this case is rather to choose a filtration power as low as possible, which should not however go below zero.

Regarding the objective parameter "suction resistance" it is worth highlighting that during the consumption of a tobacco product, consumers prefer a certain range of suction resistance. For conventional cigarettes, the filter serves to (apart from adjusting the "delivery") adjust the suction resistance of the cigarette.

By trend, for HNB products, the contribution to the suction resistance of the mouthpiece side filter (mouthpiece) should 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 contribution to suction resistance. Low suction resistance of the filter (nozzle) leads to desired degrees of freedom for the rest of the components of the HBN device.

However, suction resistance and filtration power are closely linked to each other. Both can be reduced in various ways, which however negatively influences other parameters.

For example, suction resistance and filtration power can be reduced by reducing the filter length. However, once the filter length is less than the filter diameter, processability becomes problematic. Also, a shorter filter leads to a shorter cooling extent, which is a problem for heat balance.

Alternatively or in addition to this, suction resistance and filtration power can be reduced by reducing the weight per volume fraction of the fiber in the filter material 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 reached.

Alternatively or in addition to this, the suction resistance and filtration power can be reduced, raising the filament count. For constant filter diameter and given fiber weight per unit volume, with increasing filament title, the filtration power and suction resistance decrease, which is desirable for HNB products with respect to conventional products. Since, as mentioned above, the Filtrona hardness barely depends on the filament count, the hardness is not negatively influenced either.

Regarding the objective parameter "visual effect", it is highlighted that the consumer prefers a mouthpiece with a flat white cross-sectional surface with a side mouth. However, there are also products that are formed into a tube with a side mouth.

Regarding the temperature of the smoke, it is highlighted that the temperature of the smoke does not represent any problem for current conventional products. However, for common HNB products on the market the smoke temperature is noticeably high and for some consumers it is unpleasantly high. Furthermore, for common HNB products on the market, cooling is required to cool the evaporated components, whereby an aerosol arises from the gaseous components.

For common HNB products on the market, certainly the distance of the heating element to the mouth end of the HNB item is the most important parameter for aerosol cooling. Thus, for example, it is known to place a so-called cooling element downstream of the tobacco portion and the support element. The cooling element may be in the form of a crimped polylactide sheet or in the form of a cardboard tube, where - apart from cooling - this element connected downstream of the tobacco portion and the support element is particularly suitable also for the function as a position fixator, which provides mechanical stability.

Finally, the nozzle materials have to satisfy the target cost-effectiveness parameter. There is in particular a need for suitable nozzle materials, which can be manufactured with as low a use of materials as possible and with as low a process costs as possible.

Although conventional cigarette filters, which are usually constructed from cellulose acetate filaments, guarantee optimal filtration of smoke ingredients, these filter materials are often usable only conditioned by other applications, in particular for HNB products or cigarettes. electronics, since for these applications the filter materials or nozzle materials have to take on other functions.

HNB products, as well as conventional smoking articles, generally have the disadvantage that the aerosol inhaled by the user is received at a high temperature. Occasionally this is unpleasant for the user. Particularly for HNB products, the nozzle materials are suitable for cooling the aerosol, with as low a filtration power as possible.

But also for classic cigarettes, in particular so-called slim or ultra-thin cigarettes, that is, cigarettes with a small diameter of for example 5.0 mm to 6.5 mm, the filter materials or materials for the mouthpiece must offer a power of Reduced filtration and increased cooling and improved haptic properties (firm grip but not harder) - compared to filter materials for full-size cigarettes. Naturally, less smoke/flavor is produced there during burning than with a large cigarette. In order not to further reduce the flavor, a low filtration power is intended. If only the amount of filter material is reduced for this purpose, the hardness of the filter may eventually be insufficient.

Also slim or ultra-thin cigarette filters have, with the same fiber density, clearly higher suction resistance than large filters, which is generally desirable.

For both HNB products and ultra-thin cigarettes, it was proposed to achieve the desired filtration power, reduced with respect to condensable components such as tar, as well as sufficient filter hardness, by raising the filter titer while preserving the total titer. This approach has, however, the disadvantage that such fiber materials with high filament count have economic disadvantages in the spinning machines usually used. During the production of conventional filter tow, a solution of about 30% cellulose 2.5 acetate in acetone is compressed through spinning nozzles, the acetone is evaporated on a spinning spindle by blowing hot air, a multiplicity is consolidated of filaments (1,000 to 35,000) until it gives a ribbon and then this is curled in a Strauch chamber. In the case of higher filament counts, a greater amount of solvent has to be evaporated for each filament which, due to the greater ratio of the cross-sectional area of the filament to the filament surface, takes more time and has as consequently lower spinning speeds.

On the basis of this statement of the problem, the present invention bases its objective of indicating a material that is suitable for a wide range of application in smoking articles.

In particular, the present invention bases the objective on indicating a filter material with low suction resistance and low filtration power, where with the filter material a Filtrona hardness that is sufficiently high and as constant as possible for use can be achieved. in smoking articles, and where however the filter material is manufactured in a particularly cost-effective manner.

Furthermore, the filter material should be suitable for manufacturing a filter with a uniform, white front side and flat mouth side.

In this context, it is further desirable that the filter material shows a selective filtration effect on phenols.

The filter material should be suitable in particular for reliably cooling a hot gas laden with particles, so that the temperature of the gas, aerosol or vapor taken by the user of a smoking article can be reduced.

Furthermore, the material should be suitable so that when using the material as a filter material for particularly thin or ultra-thin cigarettes, an adjustable and particularly reduced suction resistance is achievable compared to large filters.

These objectives are achieved by the respective objects of independent claims 1, 8 and 12.

Accordingly, the present invention relates in particular to a material for forming a mouthpiece for smoking articles, wherein the material exhibits a filling material, which is based on cellulose acetate filaments, which are at least partially formed as hollow filaments of cellulose acetate. The filler material partially formed as hollow cellulose acetate filaments exhibits a lower density and a higher fill value, compared to classical cellulose acetate filaments, which do not have a hollow shape, and are usually used for cigarette filters. . By providing such a filler material, the performance that can be achieved with the nozzle and the application spectrum can be significantly increased.

Under the term "hollow fiber" used herein is meant in particular a preferably cylindrical fiber, which in cross section exhibits one or more universal hollow spaces. The hollow fibers are preferably at least partially crimped. However, the invention is not limited to crimped hollow fibers, but also relates to non-crimped fibers or their use.

According to variant embodiments of the present invention, the hollow fibers are at least partially realized as multi-strand hollow fibers. Compared to single-strand hollow fibers, multi-strand hollow fibers are significantly more stable to bending, which is why particularly high Filtrona hardnesses are achievable without high compaction of the material.

The term "Filtrona hardness" used herein means the hardness of the filter determined in accordance with the Filtrona principle. In this principle, the hardness of the filter is determined by compressing a 12 mm diameter cylindrical bar with its flat front side vertically with a load of 300 g on a horizontally positioned filter bar. The ratio of the compressed diameter to the starting diameter previously determined through the first contact results in the percentage of Filtrona hardness.

According to preferred embodiments of the present invention, the hollow cellulose acetate filaments at least partially exhibit a three-lobed cross-sectional shape, i.e., three-armed star shape. Such a cross-sectional shape is offered when the cellulose acetate filaments should exhibit as large a specific surface area as possible, in order to make possible, for example, a high filtration power with simultaneous use with a saving of raw materials. Alternatively, it is possible to obtain the desired large specific surface area by means of a bundle of extremely fine filaments with circular cross section. However, other cross-sectional shapes for the hollow cellulose acetate filaments are also conceivable, such as a square cross-section.

The filter and/or filling material can be manufactured in a cost-effective manner and can be processed alone or with classic cellulose acetate filaments, which do not have a hollow shape, until giving a filter bar with adequate resistance to suction and Optimized filtration properties.

Because the filter and/or filler material exhibits a filler material which is based on cellulose acetate filaments, which are at least partially configured as hollow cellulose acetate filaments, a low suction resistance can be realized. and a low filtration power, since the filaments of the filter and/or filling material formed at least partially as hollow filaments of cellulose acetate, exhibit a low external surface area, referred to the total volume of the fiber. In this case, it is preferred that the filter and/or filler material filaments formed at least partially as hollow cellulose acetate filaments exhibit as round a cross section as possible. In this context, it was surprisingly determined that due to the filaments with the filter and/or filling material formed at least partially as hollow cellulose acetate filaments, particularly high Filtrona hardnesses can be realized. It has really been emphasized that the filter that is formed at least partially of hollow filaments of cellulose acetate (hollow fibers), achieves the minimum desired Filtrona hardness, with a low weight of fiber per unit of volume.

Since it is based on cellulose acetate filaments, the filter and/or filling material is suitable for the manufacture of a filter with a uniform, white front side and flat lateral mouth, where a filtration effect can also be realized. selective on phenols.

By using a filter and/or filling material, which is based on cellulose acetate filaments, filter rods can be manufactured on the one hand, in particular for cigarettes, which from the point of view of the discussion regarding smoking and health, demonstrably exhibit properties that stand out with respect to the phenomenon of specific retention. In this way, a cellulose acetate filter filters nitrosamines and phenols that are questionable for health much more efficiently than condensate and nicotine. Furthermore, the taste of smoke from currently common tobacco blends, such as "American Blend", "Germán Blend" and "Virginia" in combination with a cellulose acetate filter stick is evaluated by the smoker as the most pleasant. . Another advantage that should not be underestimated of a cellulose acetate filter bar is based on the optical homogeneity of the filter cutting surfaces.

Since the filter and/or filler material is at least partially formed of hollow cellulose acetate filaments that serve as filler material, for filter bars manufactured from the material according to the invention, the resistance to Suction and filtration power can vary over a wide range.

In particular it has been shown that a filter material consisting at least in certain areas of hollow cellulose acetate filaments exhibits an improved thermal cooling effect. It was determined that by using hollow cellulose acetate filaments as a filler material, a very low filtration effect, i.e., support effect, can still be achieved for the suspended substances and gases that are to be removed. It is presumed that this effect is achieved because by the hollow cellulose acetate filaments, the surface or the flow of the gas to be purified or the air changes so that the suspended substances possibly present in the gas or air They are barely retained. Another reason could be that by using hollow cellulose acetate filaments another particularly advantageous surface structure of the filter material is achievable.

The filter and/or filling material further has the advantage that a particularly adjustable cooling of a hot gas loaded with particles (in particular aerosol) is made possible so that the temperature of the gas, aerosol or vapor absorbed by the user of a smoking article or HNB product. By varying the proportion of the hollow cellulose acetate filaments in the filter and/or filling material, the intended cooling effect can be adjusted specifically for the application. It is also important to mention that the hollow cellulose acetate filaments (= hollow fibers) in the filter and/or filler material are essentially bypassed and are poorly penetrated. From geometric considerations it is evident in this regard that the distance from fiber to fiber is essentially greater than the via (hollow proportion) of the hollow fiber. The viscosity of the aerosol (essentially air) then leads to the path of lowest resistance being chosen (i.e. it flows between the filaments and not through each individual filament).

In other words, for the filter and/or filler material the effective filtration surface is in no case maximized, since the hollow cellulose acetate filaments in the filter and/or filler material are not crossed.

In particular, the hollow cellulose acetate filaments can thus exhibit folding sites, which occlude the path of the hollow cellulose acetate filaments, without this having an influence on the performance of the filter and/or filler material with respect to to the adjusted target parameter.

In particular, in this context it is worth mentioning that hollow cellulose acetate filaments made as hollow fibers do not have to be universally hollow, but can also be partially occluded by folds. They can also deviate from an ideal circular shape.

In configurations, it is provided that the hollow cellulose acetate filaments of the filter and/or filling material serve on the one hand as a support material and on the other hand as a cooling material. Since the hollow cellulose acetate filaments simultaneously serve as a carrier material, particularly compact mouthpieces are feasible, in which the dimensions of the smoking article do not have to be increased.

It is conceivable, for example, that the filter and/or filling material exhibits, in the longitudinal direction of the nozzle, zones bordering each other with hollow cellulose acetate filaments and with non-hollow cellulose acetate filaments. A mixture of hollow and non-hollow cellulose acetate filaments would also be imaginable. Alternatively or in addition to this, the hollow and non-hollow cellulose acetate filaments may be arranged in layers and then folded. In this way, an area as flat as possible of the hollow cellulose acetate filaments serving as cooling material is feasible, by means of which the gas loaded with particles can be better cooled.

The filter and/or filling material can be incorporated in the smoking article in such a way that in particular the hollow cellulose acetate filaments are arranged essentially along the flow direction of the particle-laden gas or aerosol. . In this way it can be achieved that with the filter and/or filling material only a small loss of pressure is caused during suction by the user at the mouthpiece, so that the suction is not seen as exhausting or unpleasant by the user. user. By varying the alignment of the hollow cellulose acetate filaments with respect to the flow direction of the particle-laden gas or aerosol, the suction resistance of the filter and/or filler material can be varied within a wide range and adjust to the respective application case.

Since the proportion of hollow and non-hollow cellulose acetate filaments in the filter and/or filler material varies, and/or since the alignment of the hollow and non-hollow cellulose acetate filaments with respect to the direction of flow of the particle-laden gas or aerosol into the filter and/or filler material, not only the cooling and filtration power, but also the suction resistance of the filter and/or filler material can be adjusted.

Alternatively, it is contemplated that the filter and/or filler material consists only of hollow cellulose acetate filaments. Then, the filter and/or filling material is suitable for optimal cooling power, with a reduced filtration power.

Another configuration of the filter and/or filling material provides that the filter and/or filling material is arranged in front of the nozzle, as a separate segment in the direction of the flow of the particle-laden gas or aerosol. The separated segment may exhibit a multiplicity of shapes. By way of example, a preferred cylindrical shape is described, to which the invention should not be limited. Conventional smoking articles have a shape that is usually essentially cylindrical. In this regard, the separated segment can also be arranged in front of a possible filter, in the direction of the flow of the particle-laden gas. The filter and/or filling material that serves as a cooling device and is formed as a separate segment can, for example, consist entirely of hollow cellulose acetate filaments.

It is also conceivable that the separated segment exhibits a covering, for example of paper or a type of casing, so that the hollow cellulose acetate filaments serving as a cooling material can be encapsulated. The envelope or housing exhibits an inlet opening and an outlet opening for the particle-laden gas or aerosol, through which it flows due to the user's section through the mouthpiece. The hollow cellulose acetate filaments serving as a cooling material can be installed, for example, in encapsulated form, also optionally in or with the smoking article. In this way, the user has the option of only cooling the gas loaded with particles, if considered necessary.

As already mentioned, in particular the suction resistance of a filter bar formed from the filter material can change, in particular within a significantly larger range, by varying the proportion of hollow cellulose acetate filaments in the filter material. .

In summary, it is thus recorded that by using a filter material, which consists at least partially of hollow cellulose acetate filaments, the suction resistance and filtration power can be adjusted over a wide range to the respective requirements. , and even more flexibly than is the case for filters made of conventional cellulose acetate filament materials. Furthermore, a cooling effect can be variably set.

In particular, the present invention allows a cellulose acetate nozzle or filter to be formed, which is normally present in the form of a rope of endless filaments oriented essentially longitudinally, wherein the endless filaments are preferably crimped, so that short zones of the individual filaments are arranged irregularly in non-parallel, converging and divergent directions, compared to the predominantly longitudinal direction of the rope.

In one possible configuration of the filter material, the surface structure of the filter material can be varied by using particularly 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 Ix is a measure of the curl intensity. The crimp index of a filter tow is determined by a suction test (force/elongation correlation). It is defined as the ratio of the extended L2 length under test load minus the exit length to the exit length under the previous L1 load:

I<x>=(L2-L<i>)/L<i>*100%

In this regard, the test load is 25 N and the preload is 2.5 N. The length between jaws is 250 mm. The curl index is determined in the suction test with a constant rotation speed of 300 mm/min in a G02 apparatus from Borgwaldt GmbH, Hamburg. For each measurement, 10 individual measurement values are taken. The test occurs under normal climate: 20 °C and 60% relative humidity.

Preferably the filter material is in the form of a filter tow consisting of endless filaments of cellulose acetate crimped in a Stauch chamber, and in particular filaments of 2,5 cellulose acetate. For the production of filter tow, a solution of approximately 30% cellulose 2.5 acetate in acetone is compressed through special spinning nozzles, the acetone is evaporated in a spinning spindle by blowing hot air, a multiplicity of filaments (1,000 to 35,000) to form a ribbon and then this is curled in a Strauch chamber. The product is then dried, packed in a tray container and finally compressed into bales weighing 300 to 600 kg.

Spinning nozzles are used to spin the spinning solution, which are configured to spin hollow cellulose acetate filaments and/or cellulose acetate spinnable fibers.

After transporting the bales of filter tow to the filter or cigarette manufacturer, the filter tow is removed from the bale and processed in a filter bar machine, as described for example in US 5,460,590 A , until giving filter bars. In this regard, the filter tow is stretched in a stretching direction, it is provided with an additive that serves for the adhesion of the filaments and then, after the formation of a three-dimensional wick, it is introduced into the format part with the help of a funnel. of feed, it is compacted there axially transversely, wrapped with paper and cut to the final length of the filter bar.

The additive applied for the adhesion of the filaments can be a high-boiling solvent for cellulose acetate, such as glycerin triacetate (triacetin), which after its application momentarily solvates the surface of the filaments. Wherever two filaments randomly touch, a firm adhesion site occurs some time later, as the excess additive migrates to the surface of the fiber, thereby solidifying the droplets of previously liquid solution. After storage of less than one hour, mechanically firm, three-dimensionally cross-linked filter bars are obtained, conditioned by the aforementioned migration of the curing agent, which are also called "spatial filter", and which exhibit a low packing density. from usually 20 mg/ml to 90 mg/ml, preferably 30 to 70 mg/ml and even more preferably 40 to 60 mg/ml. Due to their hardness, these filter bars can be processed at high speeds, without difficulties, in modern cigarette machines.

Research has shown that by using hollow cellulose acetate filaments in the filter material, the filtration power of space filters can be decreased while preserving the objectives, such as length, diameter, suction resistance and filament count, and can be increased. cooling power.

Since the proportion of hollow fibers (hollow filaments of cellulose acetate) in the filter material is correspondingly increased, despite the increase in the cooling power and reduction in the filtration power, the suction resistance can be maintained in the low range required, without an increase in the filament titer.

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

According to the invention, the void proportion in the filter material is preferably 25 to 90% and preferably 50 to 80%. This hollow proportion makes, on the one hand, a decisive contribution to the filtration power and, on the other hand, to the reduction of the suction resistance, which is only achievable due to a corresponding proportion of hollow fibers in the filter material. , but not with closed filaments. The void ratio corresponds to the ratio of the "hollow" surface of the filter material to the "total" cross-sectional surface of the fibers.

In this context it should be mentioned that the filter material according to the invention is also distinguished in particular in that the filament diameter of the cellulose acetate filaments is clearly larger than the filament diameter of other (synthetic) hollow fibers, the diameter of which of the filament is in the range between 10 and 30 |jm. 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 jm (outer diameter). In this way the void ratio can be increased and thus the specific filtration power of the filter and/or filler material according to the invention can be significantly reduced, while simultaneously the cooling power of the filter and/or filler material is increased. according to the invention.

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

According to non-limiting embodiments, either a thermoplastic cellulose ester fiber material or, in the case of a non-thermoplastic cellulose ester, a water-soluble adhesive can be used for the manufacture of a filter. For the first case of a cellulose ester thermoplastic fiber material, two cases can be differentiated. In the first case, the fiber material is manufactured from a cellulose ester that is already thermoplastic in nature, such as cellulose acetobutyrate. In this case, the filter tow can be processed without further measures into the filters according to the invention. In the case of a non-thermoplastic starting polymer, such as 2,5-cellulose acetate, it has to be converted into a thermoplastic by adding a suitable plasticizer.

To produce the filter, a filter tow is removed from a bale, deployed pneumatically and spread according to conventional procedures for spatial filters.

In the context of the teaching according to the invention, the weight of acetate 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 filter length is exceeded, then such a product is not sufficiently profitable. Preferably a minimum value of about 2 mg per mm of filter length is satisfied. If it is below this value, then the desired cigarette filter hardness of at least 88% is no longer satisfied according to the state of the art.

Within the scope of the teaching of the invention, the suction resistance can be a maximum of 2 mm daPa per mm of filter length and at least approximately 0.1 daPa per mm of filter length and is in particular at 0. 2 daPa to 1 daPa per mm of filter length. Particularly, a suction resistance of 0.3 daPa to 0.7 daPa per mm of filter length is preferred. Preferably a minimum value of 0.3 daPa per mm of filter length is satisfied. If it is below this value, then the desired filter hardness of at least 88% is no longer satisfied, according to the state of the art.

Some essential aspects are consolidated below:

According to a first aspect, the present teaching relates to a filter and/or filler material for mouthpieces for use with smoking articles or HNB products, wherein the filter and/or filler material is based on filaments of cellulose acetate, which are formed at least partially as hollow and/or tubular filaments of cellulose acetate.

According to a variant embodiment of the filter and/or filling material, the cellulose acetate filaments exhibit endless hollow and particularly crimped cellulose acetate filaments and/or endless hollow and particularly crimped cellulose acetate filaments. and cut.

According to a variant embodiment 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 a variant embodiment of the filter and/or filling material, the cellulose acetate filaments are formed of a thermoplastic cellulose material where the cellulose acetate filaments, as long as they include a plasticizer, contain them homogeneously distributed. , and/or where a water-soluble adhesive is present on the surface of the cellulose acetate filaments.

According to a variant embodiment of the filter and/or filling material, in the case of the use of a plasticizer, the plasticizer content is between 1 and 40%.

According to a variant embodiment of the filter and/or filling material, in the case of using a plasticizer, this is triacetin, triethylene glycol diacetate and/or citric acid diethyl ester.

According to a variant embodiment of the filter and/or filling material, the cellulose acetate filaments exhibit a fineness between 5 to 30 Denier, preferably between 10 to 25 Denier and even preferably between 15 to 20 Denier.

According to a variant embodiment of the filter and/or filler material, the total title of the filter and/or filler material is between 4,000 and 40,000 Denier and preferably between 6,000 and 30,000 Denier.

According to the invention, the void proportion in the filter and/or filler material is 25% to 90% and preferably 50% to 80%, referred to a cut orthogonal to the fibers of the filter material and/or filler. stuffed.

According to a variant embodiment of the filter and/or filling material, the filament diameter of the cellulose acetate filaments is in a range between 30 and 150 |jm (outer diameter), and preferably in a range between 50 and 120 jm (external diameter), and according to the invention in a range between 60 and 100 jm (external diameter).

According to a variant embodiment of the filter and/or filling material, the mass proportion of hollow cellulose acetate filaments is between 20 and 100%, preferably between 50 and 100% and even more preferably between 70 and 100%.

According to a variant embodiment of the filter and/or filling material, the hollow cellulose acetate filaments are relative to each other with reciprocal distances in an irregular arrangement, where the cellulose acetate filaments are intertwined, and where The cellulose acetate binding filaments are reciprocally coiled and/or entangled.

According to a variant embodiment of the filter and/or filling material, a binder, in particular an organic or inorganic binder, is additionally supplied to hold the cellulose acetate filaments together.

According to another aspect, the present invention relates to a mouthpiece for use with smoking articles or HNB products, wherein the mouthpiece exhibits a filter and/or filling material of the type according to the invention mentioned above.

According to another aspect, the present invention relates to a cigarette filter or a cigarette filter element, which exhibits a filter and/or filling material of the type according to the invention mentioned above.

According to embodiment variants of the cigarette filter or the cigarette filter element, at least one feature of the features mentioned below is realized:

■ the fiber density of the filter and/or filler material is between 10 and 70 kg per m3 and preferably between 20 and 70 kg per m3 and even more preferably between 40 and 60 kg per m3;

■ the cigarette filter or cigarette filter element exhibits a Filtrona hardness of at least 88% and preferably a Filtrona hardness of 88% to 95% and even more preferably a Filtrona hardness of 90% to 93%;

■ the cigarette filter or cigarette filter element exhibits a suction resistance of at least 0.1 daPa per mm of filter length and preferably a suction resistance of 0.2 daPa to 1.0 daPa per mm of filter length and even more preferably a suction resistance of 0.3 daPa to 0.7 daPa per mm of filter length;

■ the filter and/or filler material exhibits a plasticizer, where the plasticizer content is between 1% and 40%.

According to variant embodiments of the cigarette filter or the cigarette filter element, in particular a capsule-shaped or capsule-type flavor delivery element is additionally incorporated into the filter and/or filling material.

According to variant embodiments of the cigarette filter or the cigarette filter element, the cigarette filter or the cigarette filter element exhibits, in addition to the hollow cellulose acetate filaments, solid cellulose acetate filaments.

According to another aspect, the present teaching relates to the use of the filter and/or filler material according to the invention, in smoking articles or in HNB products.

According to another aspect, the present invention relates to a process for the manufacture of a filter and/or filler material for mouthpieces for use with smoking articles or HNB products, wherein the filter and/or filler material filler preferably consists of cellulose acetate filaments and/or cellulose acetate spinning fibers, wherein a solution of cellulose acetate with acetyl index of at least 53% in acetone is compressed through a spinning nozzle with several openings, and where then, if necessary, the cellulose acetate filaments are cut to give cellulose acetate spinning fibers and where a multiplicity of the cellulose acetate filaments and/or acetate spinning fibers are consolidated of cellulose thus obtained, until giving a filter tow, which if necessary is crimped, where the spinning nozzle, through which the cellulose acetate solution is compressed, is configured so that hollow filaments of cellulose acetate.

Claims (15)

1. Method for manufacturing a filter and/or filler material for mouthpieces for use with smoking articles or HNB products, consisting of cellulose acetate filaments and/or cellulose acetate spinning fibers, wherein a solution of cellulose acetate with an acetyl value of at least 53% in acetone is compressed through a spinning nozzle with several openings, and where then if necessary the cellulose acetate filaments are cut into fibers for spinning of cellulose acetate and where a multiplicity of the filaments of cellulose acetate and/or fibers for spinning of cellulose acetate thus obtained are consolidated to give a filter tow, which if necessary is crimped, where the nozzle of spinning, through which the cellulose acetate solution is pressed, is configured so that hollow filaments of cellulose acetate are spun, wherein - referring to a section orthogonal to the figures of filter material and/or filler - the void proportion in the filter and/or filler material is 25% to 90% and preferably 50% to 80%, and where the filament diameter of the cellulose acetate filaments is in a range between 60 and 100 |jm. 2. Method according to claim 1, wherein the crimp index of the cellulose acetate filaments is between 10% and 60%, in particular between 20% and 50%. 3. Method according to claims 1 or 2, wherein the cellulose acetate filaments contain a homogeneously distributed plasticizer; and/or where a water-soluble adhesive is found on the surface of the cellulose acetate filaments. 4. Method according to one of claims 1 to 3, wherein the cellulose acetate filaments and/or cellulose acetate spinning fibers exhibit a plasticizer, and wherein the plasticizer content is between 1 and 40%; I wherein the cellulose acetate filaments and/or cellulose acetate spinning fibers exhibit a plasticizer, and wherein the plasticizer is triacetin, triethylene glycoldiacetate and/or citric acid diethylester. 5. Method according to one of claims 1 to 4, wherein the cellulose acetate filaments exhibit a fineness between 5 and 30 Denier, preferably between 10 and 25 Denier and even preferably between 15 and 20 Denier; I wherein the total title of the filter and/or filler material is between 4,000 and 40,000 Denier and preferably between 6,000 and 30,000 Denier. 6. Method according to one of claims 1 to 5, wherein the mass proportion of hollow cellulose acetate filaments is 20 to 100%, preferably 50 to 100% and even more preferably 70 to 100%. 7. Method according to one of claims 1 to 6, wherein the hollow cellulose acetate filaments are together at mutual distances in an irregular arrangement, and wherein the cellulose acetate filaments are cross-linked, wherein the cellulose acetate bonding filaments are reciprocally coiled and/or entangled; I wherein a binder is also provided, in particular an organic or inorganic binder to bind the cellulose acetate filaments. 8. Mouthpiece for use with smoking articles or HNB products, wherein the mouthpiece exhibits a filter and/or filler material, which is manufactured according to a method according to claims 1 to 7. 9. Nozzle according to claim 8, wherein the fiber density of the filter and/or filling material is between 10 and 70 kg per m3 and preferably between 20 and 70 kg per m3 and even more preferably between 40 and 60 kg per m3; I wherein the cigarette filter or the cigarette filter element exhibits a Filtrona hardness of at least 88% and preferably a Filtrona hardness of 88% to 95% and even more preferably a Filtrona hardness of 90% to 93%; I wherein the cigarette filter or the cigarette filter element exhibits a suction resistance of at least 0.1 daPa per mm of filter length and preferably a suction resistance of 0.2 daPa to 1.0 daPa per mm of filter length and even more preferably a suction resistance of 0.3 daPa to 0.7 daPa per mm of filter length. 10. Nozzle according to claims 8 or 9, wherein furthermore a flavor delivery element is incorporated into the filter and/or filling material, in particular in the form of a capsule or capsule type. 11. Nozzle according to one of claims 8 to 10, wherein the filter and/or filling material exhibits, in addition to the hollow cellulose acetate filaments, solid cellulose acetate filaments. 12. Cigarette filter or cigarette filter element, exhibiting a filter and/or filler material, which is manufactured according to a process according to claims 1 to 7. 13. Cigarette filter or cigarette filter element according to claim 12, wherein the fiber density of the filter and/or filling material is between 10 and 70 kg per m3 and preferably between 20 and 70 kg per m3 and even more preferably between 40 and 60 kg per m3; I wherein the cigarette filter or cigarette filter element exhibits a Filtrona hardness of at least 88% and preferably a Filtrona hardness of 88% to 95% and even more preferably a Filtrona hardness of 90% to 93%; I wherein the cigarette filter or the cigarette filter element exhibits a suction resistance of at least 0.1 daPa per mm of filter length and preferably a suction resistance of 0.2 daPa to 1.0 daPa per mm of filter length and even more preferably a suction resistance of 0.3 daPa to 0.7 daPa per mm of filter length. 14. Cigarette filter or cigarette filter element according to claims 12 or 13, wherein in addition in the filter and/or filling material a flavor delivery element is incorporated in particular in the form of a capsule or type. capsule. 15. Cigarette filter or cigarette filter element according to one of claims 12 to 14, wherein the cigarette filter or cigarette filter element exhibits, in addition to the hollow filaments of cellulose acetate, solid filaments of cellulose acetate.