EP0254004A2 - Aerated cigarette - Google Patents

Abstract

Ventilated cigarettes are made with a tip zone consisting of tobacco or a filter or a hollow tip, which contains, in the wrapper or wall, at least one ventilation zone. In the tip zone or between it and the tobacco roll, or in the latter, there is placed an element which consists of polymeric, not crimped spun fibers and/or filaments, which may have the shape of a disk. This element is arranged in such a manner that it is located behind the ventilation zone, when seen from the end of the tip zone facing the mouth. The spun fibers and filaments have, respectively, a diameter between 0.1 and 20 mu m and lie generally transverse to the flow of the tobacco smoke. In contrast with the known ventilated cigarettes, the cigarettes according to the invention exhibit an equalization of the tobacco smoke yield during test smoking draw-by-draw, which keeps the smoke flavor during test smoking practically uniform and results in a lowering of the total smoke yield in the particle phase as well as in the gas phase per cigarette.

Description

The invention relates to a ventilated cigarette, the mouthpiece zone of which consists of tobacco or a filter or a hollow mouthpiece and there contains at least one ventilation zone in the casing or wall.

From results of train-by-train analyzes on - commercially available - cigarettes with a mouthpiece zone made of tobacco or a filter or a hollow mouthpiece, it is known that the tobacco smoke yield increases from train to train as it is smoked. This can include have the consequence that the taste of tobacco smoke changes occasionally. It is therefore desirable to equalize the smoke yield per train when smoking, primarily for reasons of taste. An equalization of the smoke yield from train to train is also desirable because it reduces the overall smoke yield both in the particle and in the gas phase.

There are approaches in the literature to solve the problems described above:

A ventilated cigarette is described in US Pat. No. 3,526,904, in which a meltable polymer film covers parts of the ventilation zone on the tobacco rod; after the polymer film has melted - due to the approaching glowing zone - there is an increase in strand ventilation.

Collin et al. in "Contributions to Tobacco Research" 8 , 70 (1975) a ventilated cigarette filter in which the tobacco-side filter end is surrounded by a film which shrinks under the influence of heat. This film creates an artificial collapse of the filter, which increases the tensile resistance in the tobacco-side part of the filter and thus increases the degree of ventilation.

According to German Offenlegungsschrift 27 45 028, a ventilation degree increase is achieved in a filter for tobacco smoking goods with the help of a smoke acceleration opening provided on the tobacco side.

The invention has for its object to provide a ventilated cigarette, which has a mouthpiece zone made of tobacco or a filter or a hollow mouthpiece, the degree of ventilation of which increases during smoking, in order to equalize the smoke yield and taste and thus reduce the overall smoke values to achieve both in the particle and in the gas phase.

This object is achieved in a ventilated cigarette of the type mentioned by the features specified in the characterizing part of claim 1.

Advantageous embodiments of the ventilated cigarette according to the invention are specified in claims 2, 3, 4 and 5.

From German Patent 23 21 247 a filter for tobacco smoke is already known, which is composed of several filter elements, at least one of the filter elements consisting entirely of non-crimped fibers made of thermoplastic polymeric non-absorbent material, which have a diameter of less than about 5 microns and their the greater part is arranged so that the fibers are transverse to the tobacco smoke flow. However, this known filter is one without a ventilation zone (s). Furthermore, this known filter has the disadvantage that it clogs after a few puffs when a cigarette provided with such a filter is smoked, that is to say that a large amount of condensate is very quickly deposited on the filter element made of non-crimped fibers made of thermoplastic polymeric non-absorbent material, as a result of which the draw resistance is excessively increased.

The element according to the invention can
- from a mixture of staple fibers (staple fibers), i.e. fibers of finite length, and filaments, i.e. endless threads,
or
- only from staple fibers
or
- only from filaments
consist.

The staple fibers and filaments according to the invention can consist of natural or synthetic thermoplastic, polymeric materials which can be shaped into staple fibers and filaments with a diameter of 0.1 to 20 μm. Examples of such materials are
Polyolefins, such as polypropylene and polyethylene, but also substituted polyolefins, such as polytrifluoroethylene,
Polyamides such as nylon-66, nylon-6 and nylon 610,
Polyester, such as polyethylene terephthalate
- poly (methyl methacrylate),
- polystyrene.

However, polymer blends or copolymers can also be used.

In general, the staple fibers and filaments of an element according to the invention consist of a single, ie of the same polymeric material; however, the element can also consist of a mixture of staple fibers and / or filaments made of two or more polymeric materials.

The staple fibers and filaments of an element according to the invention can have the same diameter; however, it can also be staple fibers and filaments of different diameters.

The invention is explained in more detail below using an example:

example

Polypropylene with a melt index of 13 g / 10 min at 230 ° C / 2.16 kg, a density of 0.902 g / cm³ at 23 ° C and a melting range of 165-170 ° C was melted using a spinning head similar to that in accordance with German patent 25 50 463 spun into staple fibers and filaments (blow spun). The staple fibers and filaments were formed into a spunbonded fabric by being placed on a rotating drum.
By changing the spinning parameters, in particular the pressure of the air emerging from the spinning head, which contributes to the formation and drawing of the staple fibers and filaments, the following spunbonded webs were obtained in three experiments:
- Spunbond A with a weight per square meter of 85 g and an air permeability of 65 l / min.cm² at 50 Pascal (approx. 5 mm water column), consisting of spun fibers and filaments, which had an average diameter of 2 µm;
- Spunbond B with a weight per square meter of 85 g and an air permeability of 21 l / min.cm² at 50 Pascal, consisting of spun fibers and filaments, which had an average diameter of 1.4 µm;
- Spunbond C with a weight per square meter of 85 g and an air permeability of 202 l / min.cm² at 50 Pascal, consisting of spun fibers and filaments that had an average diameter of 4.8 µm.

Round flakes (slices) with a diameter corresponding to the diameter of the tobacco rod and the filter body of a commercially available filter cigarette - with a ventilation zone in the casing of the filter body - were punched out of the spunbonded fabrics A, B and C. The discs, named after the spunbonded fabrics from which they originate, discs A, B and C, were inserted into the ventilated filter cigarettes mentioned above between the tobacco rod and the filter body, which consisted of conventional crimped cellulose-2.5-acetate fibers (of course afterwards a usual wrapping was attached again), so that the filter cigarettes A, B and C were created. The staple fibers and filaments of the disks were arranged essentially transverse to the flow path of the tobacco smoke.

Due to the installation of the discs, the initial tensile resistance and thus the initial degree of ventilation of the filter cigarettes A, B and C increases slightly compared to the original filter cigarette mentioned and depending on the air permeability of the discs, as Table 1 below shows:

On the cigarettes mentioned above, i.e. on the original filter cigarette and filter cigarettes A, B and C, ventilation degree and draft resistance measurements were made during smoking. The measurements were carried out with a measuring device which makes it possible to determine the train resistance and the degree of ventilation train-by-train under CORESTA standard conditions (CORESTA = CENTER DE COOPERATION POUR LES RECHERCHES SCIENTIFIQUES RELATIVES AU TABAC).

The course of draft resistance curves during smoking has already been described by RR Baker in "Contributions to Tobacco Research" 8 , 124 (1975), where the basis of the "hot gas model" is also theoretically calculated. The measured values for the original filter cigarette determined according to this example follow that model, and a similar course of the ventilation degree curve was found. Table 2 below shows the ventilation degree and draft resistance values for the original filter cigarette during smoking.

Table 3 shows the values determined for the degree of ventilation and the draft resistance for the filter cigarette C during smoking.

Tables 2 and 3 show in particular that the degree of ventilation of the original filter cigarette only increases by about 11 percent up to the ninth pull, while the degree of ventilation of the filter cigarette C increases by about 25 percent, which ultimately leads to an equalization of the Tobacco smoke yield per train and thus also leads to a reduction in the overall smoke yield in both the particle and the gas phase.

Table 4 below shows the values determined for the degree of ventilation and the draw resistance for the filter cigarette A during smoking.

Table 5 below shows the ventilation degree and draft resistance values determined for filter cigarette B during smoking.

As can be seen in Tables 4 and 5, discs A and B in the - ventilated - filter cigarettes achieve a very significant increase in the degree of ventilation during smoking, which of course leads to a very strong equalization of the smoke yields per train and a reduction the total smoke yield per cigarette leads.

Finally, with the original filter cigarette and filter cigarettes A and B, train-by-train smoke analyzes were carried out under CORESTA standard conditions. As shown in Tables 6, 7 and 8 below, and as was to be expected on the basis of the ventilation degree measurements, the filter cigarettes A and B - compared to the original filter cigarette - showed a clear homogenization of the amount of tobacco smoke produced train by train and thus a very strong reduction in the total smoke yield per cigarette.

The invention has the following advantages:
The ventilated cigarette according to the invention shows - compared to commercially available ventilated cigarettes - an equalization of the smoke yield when smoking step by step, whereby the taste of the tobacco smoke remains practically the same during the smoking.
Furthermore, a reduction in the overall smoke yield in the particle phase as well as in the gas phase per cigarette is achieved.

Claims (5)

1. Ventilated cigarette, the mouthpiece zone of tobacco or a filter or a hollow mouthpiece and there contains at least one ventilation zone in the casing or wall, characterized in that in the mouthpiece zone or between this and the tobacco rod or in the latter a polymeric non-crimped staple fibers and / or filaments existing element is arranged so that it is, seen from the mouth-facing end of the mouthpiece zone, behind the ventilation zone, the staple fibers and filaments each having a diameter of 0.1 to 20 microns and substantially transverse to Flow path of tobacco smoke are arranged. 2. Ventilated cigarette according to claim 1, characterized in that the element has the shape of a disc, a ball or a ring. 3. Ventilated cigarette according to claim 1 or 2, characterized in that the element partially or completely fills the cross section of the mouthpiece zone or the tobacco rod. 4. Ventilated cigarette according to claim 1, 2 or 3, characterized in that the element is located at a distance of up to 30 mm from the mouth-facing end of the mouthpiece zone. 5. Ventilated cigarette according to claim 1, 2, 3 or 4, characterized in that the staple fibers and filaments each have a diameter of 1 to 5 microns.