WO2001064061A1 - Item for smoking - Google Patents

Abstract

The invention relates to a ventilated filter cigarette, comprising a covered tobacco strand (1) and a filter (20) with ventilation means, with at least two filter pieces (22, 23). Ventilation holes (14) are arranged in the region of the mouthward filter piece (22). Furthermore, the mouthward filter piece (22) is made from a single filter segment (22), whilst the strandward filter piece (23) comprises a filter segment with a core (24) and a shell (26), a so-called coaxial filter piece or a coaxial filter.

Description

 A smoking article

The invention relates to a ventilated filter cigarette according to the preamble of patent claim 1.

Filter constructions for use in tobacco smoke filters, which consist of several filter parts with different material properties, are used in the prior art to solve various tasks. In addition, the ventilation of filters is used to ensure a milder smoke and a lower pollutant supply.

EP 474 940 B2 and EP 608 047 B1 describe smoke filters in which a middle core segment consists of a filter material different from the jacket. These smoke filters are also called core or coaxial filters. In one embodiment of EP 474 940 B2 (FIG. 5), the filter consists of two longitudinal filter sections. namely the ventilated strand-side core filter part and a mouth-side monofilter part, the mouth-side monofilter part having an aesthetic effect. The disadvantage of the smoke filters mentioned is that in any case the covering of the inner core of the core filter section consists of a material which is permeable to the smoke, so that the smoke can flow perpendicular to the interface between the core and the jacket of the core filter.

EP 0 558 166 B1 describes a ventilated filter cigarette which likewise has a monofilter section at the mouth end and a core filter section on the strand side. However, this filter cigarette has a hollow chamber between the two filter elements, which is filled with an adsorbent (e.g. activated carbon). The consequence of this is that the smoke flavor and the composition of the smoke components change drastically as a result of the adsorbent, which is not accepted by many smokers.

EP 0 880 904 AI and DE 39 01 226 Cl accomplish the task of using a cigarette with a coaxial arrangement of both the tobacco rod and the filter to realize low condensate values, which is primarily achieved by the coaxial structure of the tobacco rod. A disadvantage of this design is the high cost of special manufacturing units that are necessary for the production of the coaxial strand.

EP 539 191 B1 sets itself the task of providing a ventilated filter cigarette with a particularly light weight. The disadvantage here is that the densities of the materials used (both tobacco rod and filter) have to be minimized in order to realize a particularly light-weight cigarette, which extremely limits the possibilities of varying the equipment of the cigarette. Here the ventilation zone is located in the filter section on the side of the line.

The object of the invention is to provide a ventilated filter cigarette which does not have the disadvantages mentioned above and whose filter elements bring about a reduction in the particle phase of the smoke (such as nicotine) and at the same time achieve a disproportionate reduction in the gas phase smoke components, the filtered smoke should retain a composition that is acceptable in terms of taste to the consumer.

In addition, with the advantages mentioned above, the filter should allow a wide range of variation for the sensory, haptic and optical configuration.

Another task is to decouple the tensile resistance of the filter from the retention of the filter, i.e. to achieve an increase in the retention capacity for smoke constituents without having to accept a strong increase in the draft resistance, which is inevitable with conventional filter designs.

Another object of the invention is to provide a product with the advantages mentioned above for markets in which chamber filters and in particular those which are filled with activated carbon are rejected for both sensory and haptic reasons.

A filter cigarette of the type mentioned at the outset serves to achieve this object and also has the characterizing features of patent claim 1.

The invention is described below using exemplary embodiments:

FIG. 1 shows the schematic illustration of a filter cigarette according to the invention. FIG. 2 shows the schematic illustration of a further embodiment of the filter cigarette according to the invention.

This filter cigarette consists of a strand part 10 and a filter 20. The strand part 10 is formed by a one-piece tobacco rod 11 and a casing 12 surrounding the tobacco rod 11. The filter 20 consists of at least two filter parts 22 and 23 and is connected to the strand part 10 by a wrapping paper 13 which is at least 3 mm longer than the filter 20. The tobacco rod 11 is usually between 55 and 75 mm long, while the length of the filter 20 is between 21 and 27 mm.

The filter 20 is ventilated in the area of the mouth-side filter part. The degree of ventilation can be selected in the range from 10 to 90%.

In the area of the mouth-side filter part 22, the wrapping paper 13 is provided with ventilation holes 14 as ventilation means, which are arranged in the form of 1 to 3 rows, preferably 2 rows of holes, around the filter 20, in the area of the strand-side filter part 23, however, is the wrapping paper 13 completely impermeable. Ventilation air is sucked into the filter 20 through the ventilation holes 14 when smoking, which leads to a disproportionate reduction in the gas phase components of the tobacco smoke being achieved in comparison with the reduction in the particle phase. In one embodiment, the ventilation means can also protrude slightly, up to about 2 mm, beyond the mouth-side filter part into the strand-side filter part. After a deflection, the ventilation air is also drawn into the mouth-side filter part 22.

It is known to the person skilled in the art how ventilation holes are to be produced, for example mechanically or electrostatically or by laser perforations. Other also known ventilation means are tubes, cannulas or material savings.

The mouth-side filter part 22 consists of at least one filter segment. The mouth-side filter part 22 can also consist of two or more filter plugs, as shown in FIG. 2. This gives a higher possibility of variation of the filter materials, e.g. the possibility, in addition to the ventilated filter element 22b, of using a further filter element 22a on the mouth side, which can have an embossing or coloring on its visible cross-sectional area.

The strand-side filter part 23 forming a coaxial filter has a core 24 and a jacket 26 coaxially surrounding the core. The pressure drop of the core 24 can be between 10 and 50 mmWS lie. The jacket 26 is designed such that its pressure drop is at least a factor of 2 greater than that of the core 24. The jacket 26 can also be essentially impermeable to smoke. The surface 25 of the core 24 is made essentially smoke-proof or is smoke-impermeable.

The construction of the filter part 23 on the strand side causes the smoke to flow primarily through the core 24. The narrowing of the cross-section significantly increases the smoke flow velocity within this core segment, which inherently includes an increase in draft resistance with a relatively low retention. An analogous effect is achieved if the narrowing of the cross section of the material through which the smoke flows is caused by the fact that the core of the coaxial filter plug is designed to be almost impermeable and the entire smoke then flows exclusively through the jacket.

Only after the multiple increase in the smoke flow speed in the line-side filter part 23 is ventilation air supplied to a large extent in the mouth-side filter part 22 with the aid of the ventilation means 14. As a result, a reduction in the gas phase constituents which is disproportionate to the particle phase is achieved, while at the same time ensuring acceptable draft resistances for the smoker.

In contrast to the state of the art, the design options are extremely numerous within the specified objective, since the filter cigarette according to the invention allows the gas phase to be lowered proportionally without significantly influencing the speed, so that e.g. there is no typical effect which smokers call "yeast taste".

Suitable filter materials for the filter 20 are sheet-like, fibrous or granular filter materials, such as cellulose, cellulose esters, preferably cellulose acetate, meltblown filter material e.g. manufactured according to WO97 / 33026, airlaid filter material e.g. manufactured according to US 4,375,447, additive filter materials, tobacco e.g. according to DE 19925 968, reconstituted tobacco, other easily decomposable filter materials or thermoplastic filter fibers.

The addition of additives can serve for the sensory, haptic or optical improvement of the cigarette according to the invention and / or have an additional effect on the selective retention. For example, a filter element of the filter part 22 can be provided with activated carbon particles in order to increase the gas phase adsorption. To the acceptance of the cigarette To increase the consumer with the help of optical means, for example, the mouth-side filter plug can be colored. The pH values of the particle spectra and thus the taste impression can be influenced by adding acids or bases.

The addition of the additives can be done by sprinkling or spraying on the filter materials, e.g. Fibers, or by direct injection into the material strand.

Possible additives for the filter material are: flavoring agents, acids or bases in suspended or dissolved form, or additives with a selective retention effect adsorbents such as activated carbon or SiO 2. Other additives with a selective retention effect are organic acid bases e.g. Hydroxycarboxylic acids and their salts, metals and metal oxides, nitrogen components, ion exchange systems (e.g. zeolites), alcohols, polyphenols and polyphyrin derivatives.

Other additives such as plasticizers e.g. Triacetiti, triethylene glycol diacetate or citric acid diethyl ester, additives which accelerate photo degradation e.g. Titanium dioxide, additives that promote biodegradability, vitamins and / or color pigments can be used for the individual design of the desired filter construction.

Possible areas for embodiments of the cellulose acetate specification are: For the core 24, a single titer in the range from 3.0 to 8.0 den, preferably 8.0 den and a total titer in the range from 15,000 to 50,000 den, preferably 17,000 den. For the jacket 26 a single titer in the range from 1.5 to 3.0 den, preferably 2.1 den and a total titer in the range from 40,000 to 75,000 den, preferably 55,000 den.

The range of the individual titers for the mouth-side filter part 22 in the case of cellulose acetate as filter material, which can consist of two or more identical or different segments 22a and 22b, is 1.5 to 5 den and for the total titre 15000 to 60,000 den. Example 1:

The cigarette A had a 63 mm long tobacco rod 11 and a 21 mm long multi-part filter 20.

The core 24 of the strand-side filter part 23 had a diameter of 5.5 mm and a length of 8.0 mm. It consisted of cellulose acetate with a single titer of 6.0 den and a total titer of 17,000 den. The tensile resistance or pressure drop of the core 24 was 27 mmWS.

The jacket 26 coaxially surrounding the core 24 had an inner diameter of 5.5 mm and an outer diameter of 7.8 mm with a length of likewise 8.0 mm. Cellulose acetate with a single titer of 2.1 den and a total titer of 55,000 den was used as the material.

In total, the coaxial filter part had a length of 8.0 mm with a diameter of 7.8 mm.

The mouth-side filter part 22 was designed in one piece and consisted of cellulose acetate. It had a diameter of 7.8 mm and a length of 13 mm. A ventilation zone in the form of a series of laser perforations was provided in the area of the mouth-side filter part. The filter ventilation of cigarette A was 35%.

Example 2:

To evaluate the cigarette A from example 1, smoke analysis data were determined and compared with that of a cigarette VI, which was equipped with a conventional cellulose acetate filter of 21 mm in length and a single titer of 3.0 den and a filter ventilation of 18% and was smoked according to ISO. Table 1 shows results of the smoke data. Table 1:

Example 3:

The cigarette B had a 59 mm long tobacco rod and a 25 mm long multi-part filter 20.

The core 24 of the strand-side filter part 23 had a diameter of 5.5 mm and a length of 10.0 mm. It consisted of cellulose acetate with a single titer of 6.0 den and a total titer of 17,000 den. The tensile resistance or pressure drop of the core 24 was 25 mmWS.

The jacket 26 coaxially surrounding the core 24 had an inner diameter of 5.5 mm and an outer diameter of 7.8 mm with a length of likewise 10.0 mm. Cellulose acetate with a single titer of 2.1 den and a total titer of 55,000 den was used as the material.

In total, the coaxial filter part 23 had a length of 10.0 mm with a diameter of 7.8 mm.

The mouth-side filter part 22 was designed in one piece and consisted of cellulose acetate. It had a diameter of 7.8 mm and a length of 15 mm. In the area of the mouth-side filter part 22, a ventilation zone in the form of a series of ventilation holes 14 was provided, which were produced by laser perforations. The filter ventilation of cigarette B was 51%. Example 4:

To evaluate the cigarette B from example 3, smoke analysis data were determined and compared with that of a cigarette V2, which was equipped with conventional cellulose acetate filters of 25 mm in length and a single titer of 3.0 den and a filter ventilation of 38% and was smoked according to ISO. Table 2 shows results of the smoke data.

Table 2:

From the examples it becomes clear that the reduction in the gas phase components of the cigarette smoke compared to that of the particle phase is disproportionately high with the help of the new filter construction.

Claims

Patent claims 1. Filter cigarette with a covered tobacco rod and with a filter (20) having ventilation means, which consists of at least two filter parts (22, 23), the ventilation means being arranged in the area of the mouth-side filter part (22); and the mouth-side filter part (22) is an at least one-piece filter part and the tobacco rod-side filter part (23) is a coaxial filter part with a core (24) and a jacket (26); characterized in that the tobacco rod (11) is a one-piece rod; and that the pressure drop of the core (24) is smaller than the pressure drop of the jacket (26). 2. Ventilated filter cigarette according to claim 1, characterized in that the mouth-side filter part (22) consists of flat, fibrous, granular or rottable filter material. 3. Ventilated filter cigarette according to claim 2, characterized in that the filter material used is cellulose, cellulose ester, preferably cellulose acetate, meltblown filter material, AMaid filter material, filter material that can be mixed with additives, tobacco, other easily rottable filter materials or thermoplastic filter fibers. Ventilated filter cigarette according to points 2 or 3, characterized in that the filter material is mixed with an additive. 5. Ventilated filter cigarette according to claim 4, characterized in that flavorings, acids or bases in suspended or dissolved form, or selectively acting adsorbents such as activated carbon or SiO2 are used as additives. 6. Ventilated filter cigarette according to one of claims 1 to 5, characterized in that the core (24) of the strand-side coaxial filter part (23) consists of coarse titer fiber material, the value for individual titers being in the range from 3.0 to 8.0 den and the total titer is in the range of 15,000 to 50,000 den. 7. Ventilated filter cigarette according to claim 6, characterized in that the individual titer 6.0 den and the total titer is 17,000 den. 8. Ventilated filter cigarette according to one of claims 1 to 5, characterized in that the jacket (26) of the coaxial filter part (23) on the tobacco strand side is made of fiber material with an individual titer in the range of 1.5 to 3.0 and the total titer in the range of 40,000 to 75,000 den. 9. Ventilated filter cigarette according to claim 8, characterized in that the individual titer 2.1 den and the total titer is 55,000 den. 10. Ventilated filter cigarette according to claim 1, characterized in that the ratio of the pressure drop of the core (24) to that of the jacket (26) is greater than 2. 11. Ventilated filter cigarette according to claim 10, characterized in that the ratio of the pressure drop of the core (24) to that of the jacket (26) is 6. 12. Ventilated filter cigarette according to claim 1, characterized in that the surface 'of the core (34) is covered in an airtight manner or is made airtight. 13. Ventilated filter cigarette according to claim 1, characterized in that the reduction in gas phase components achieved by ventilation is between 10 and 90%. 14. Ventilated filter cigarette according to address 13, characterized in that the reduction in gas phase components achieved by ventilation is between 10 and 50%. 15. Ventilated filter cigarette according to address 1, characterized in that the Ventilation means protrude beyond the mouth-side part into the strand-side filter part, with the ventilation air being redirected into the mouth-side part.