HU176508B - Method for increasing the filtering effectiveness of tobacco-smoke filters particularly cigarette-smoke filters - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a process for producing tobacco smoke filters, especially cigarette smoke filters, which are more effective than previously known smoke filters in increasing their filtering effect by increasing the amount of harmful substances in tobacco smoke and cigarette smoke.

For decades, there has been an effort to artificially induce substances that are harmful to the health of tobacco smoke, especially cigarette smoke, by artificially triggering various physical and chemical processes.

As cigarettes are the largest mass of cigarettes consumed, the process of eliminating substances that are harmful to health and unpleasant to taste is of paramount importance in enhancing the effectiveness of cigarette smoke screening.

Cigarette smoke is an aerosol of small particles suspended in air and vapor by a physico-chemical approach. In this aerosol, unwanted smoke components are present in part in the gas phase and partly in the solid phase (in the form of particles). These substances can be bound in filters fitted to the tobacco body of the cigarette:

1. mechanical capture, inertia collision, diffusion;

2. by condensation and subsequent adsorption;

3. by chemical affinity between the particulate material and the filter.

Filters of simple fibrous materials for mechanical capture, such as viscose, cellulose acetate, crepe paper, are well known to filter large-grain particulates from cigarette smoke. In practice, it is common to bind vapor and gas phase components by diffusion, condensation and subsequent adsorption. For this purpose, additives having a high specific surface area and a porous structure with a significant internal capillary system (eg activated carbon) are used as additives.

As an effective selective filtering agent, silica gel is also a preferred additive in filters, usually in combination with other adsorbent materials. Such a process is also described in NDK Patent No. 69291, which utilizes silica gel adsorbent with incorporated (5-15%) activated carbon. The advantage of this mixture is that the activated carbon selectively filters the compounds in the vapor phase, while the silica gel is highly effective in retaining the hydrophilic components of the particulate phase of the smoke, the alkaloids, formaldehydes.

According to the process described in German Patent No. 1,657,243, the particulate filter material (preferably activated carbon) is mixed with particles of a material (preferably polystyrene) which can be swollen by heat or chemical reaction. By swelling, the empty spaces around the filter soils are filled and the smoke is forced to penetrate through the filter particles.

In recent years, combined dual triple filters have become widespread, in which the fibrous material acts as a filter, as an adsorbent carrier, and as a barrier layer for various additives. By carefully designing the combined filters and selecting the filter constituents for a predetermined purpose, it is possible to control the final composition of the cigarette smoke.

A disadvantage of the known processes is that the filter additives used hitherto can no longer enhance the efficiency of selective smoke filtration, while increasing the sorption of harmful substances while preserving the great taste and flavor of the cigarette smoke to be sucked.

These drawbacks of the known processes are overcome by the process of the present invention which, by using a preferred filter additive or mixture of additives, results in a better filtering effect, both in terms of quality and economy, of the filters produced by the prior art processes.

The present invention is based on the discovery that various variants of highly porous, low porosity, low density filter pearls produced by special swelling for filtering tobacco smoke, and especially cigarette smoke, both alone and with other filter additives (e.g., activated carbon, silica gel), as filter components can be used to increase selective filter efficiency.

It has been found that hydrophilic (P) and hydrophobic (HP) variants of filter perlite, as filter additives, can retain from 50% to 80% of their crude condensate from cigarette smoke, depending on their particle size and production conditions.

The process of the present invention involves the use of various variants of perlite (P, HP) as a filter additive, alone, in combination with other additives (e.g., activated carbon, silica gel). The combination of a pure perlite filter made with the process and a filter with perfitactive carbon (volume ratio of additives: preferably 2/3 to 1/3) retains the crude condensate, a substance harmful to health, than a conventional filter made with activated carbon. While the hydrophobic perlite filter binds nearly 60% of the crude condensate, mixtures of the normal and hydrophobic perlite versions with 2/3 to 1/3 by volume of activated carbon retain 45 to 48% of crude condensate, whereas conventional active this value is less than 4 &% when using a carbon filter. In addition, the use of perlite filters also improves the taste effect of cigarette smoke.

Particularly advantageous is the selective filter efficiency of a cigarette filter made of hydrophobic perlite only, which, when compared to a filter made with activated carbon, both in terms of its crude condenser and total alkaloid (nicotine) binding, is ca. 50% better, and more than 40% better at retaining volatile phenol. In this comparison, a filter made of hydrophobic perlite is also preferred for binding of dry condensate, oxo compounds and hydrogen cyanide. In addition to the high efficiency of filtering out substances harmful to health, hydrophobic perlite is also an excellent adsorbent in cigarette filters because of its low water uptake and the ability of the filtered smoke to retain its character and aroma.

Both the standard filter perlite (P) and the hydrophobic variant (HP) have particularly advantageous selective filter efficiency with a particle size of 0.1 to 1.0 mm in diameter.

It is expedient to form perlite or any other filter additive combination with perlite on crepe paper, cellulose acetate or viscose webs, then compressed with an outer wrapping paper to form a rod, which according to the present invention forms the basic filter of a cigarette filter. The base filter can be used on its own to filter out pipe smoke, but it cannot be used on its own as a cigarette smoke filter. In order to apply the latter, the so-called. a cover filter must be fitted to the suction end of the cigarette. The top filter is usually white cellulose acetate or other fibrous material. The fitted cover and base filter form the so-called filter for cigarette smoke. combined filter rod.

In the process of increasing the effectiveness of tobacco smoke filters, especially cigarette smoke filters, a preferred variant of perlite, preferably 0.1 to 1.0 Ram in diameter, is used alone or mixed with other porous structure adsorbent filter additives (e.g. activated carbon, silica gel). spread uniformly on a carrier (e.g., a crepe paper web, a viscose to a web, cellulose acetate) and, if necessary, bind with adhesive or, without carrier, use an inorganic, organic or plastic based adhesive to form a slurry, also fitted in the known manner with a cover filter to the body of the cigarette to form a multi-filter cigarette. It is an object of the present invention to insert a fibrous filter rod (preferably a paper or viscose filter rod) fitted to the body of a cigarette and a fibrous top filter (preferably a cellulose acetate based filter rod), preferably without a binder, having a particle size of 0.1-1.0 mm. a porous adsorbent consisting of perlite or a mixture of perlite with other filter additives (e.g., activated carbon, silica gel) and making a multi-filter cigarette by a known method.

The invention is illustrated by the following examples, which are illustrated by the drawings:

Example 1

According to the invention, a basic filter for cigarette smoke is produced by a combination of a fibrous filter (carrier) and a porous structure adsorbent, as shown in Figures 1, 2 and 3:

As shown in Figure 1, a crepe paper strip 1 is used to filter out the high molecular weight particulate matter from the cigarette smoke as a fibrous filter. During continuous production, the adhesive material 2 is first uniformly distributed over the crepe paper web 1, and then the activated carbon 3 and the perlite 4, which is a porous structure of the adsorbent mixture, are used to disperse the undesirable and components are bound.

Then, in a known manner, the drying step 5 is followed by the shaping of the material thus prepared into a rod 6.

Further, not illustrated in Figure 1, the rod-shaped material is wrapped in paper and wrapped with a cutting knife to form filter rods of the desired length.

As shown in Figure 2, the fiber filter used is 7 viscose webs and Figure 3 uses Π cellulose acetate web. Furthermore, the process illustrated in Figures 2 and 3 differs from the process of Figure 1 in that the basic filter is made without the use of an adhesive. A mixture of 8, 12 activated carbon and 9, 13 perlite is used here as a porous adsorbent material.

Since the basic filter rods are not suitable for filtering cigarette smoke as such, they are known as white cellulose acetate or other fibrous materials for their application. 21 cover filters must be fitted to the suction end of the cigarette. To form the cover filter 21 and the base filter 18 into a combined rod, as shown in Fig. 5, the base filter bar 18 is cut into pieces 19, 20, the cover filter bar 21 is cut into pieces 22, 23 and the pieces 20, 23 are cut into molded into a combined filter rod.

Example 2

Preparation of a basic cigarette smoke filter according to the invention using a porous adsorbent material without the use of a fibrous filter (carrier) as illustrated in Figure 4.

As shown in Figure 4, a mixture of 15 activated carbon and 16 perlite is used as the porous adsorbent material. Elements of the mixture (activated carbon 15 and 16 perlite) are pre-treated with a suspension of inorganic, organic or plastic based adhesive (not shown) and the pre-treated activated carbon 15 and 16 perlite are wrapped and heat-cured in a known manner into a cylindrical body 17. The formed cylindrical body 17 is cut into basic filter rods 18 of desired length and diameter.

Given that basic smoke filters were also manufactured in this case, a cover filter must be fitted to the suction end of the cigarette for its application. The shaping of the cover filter 21 consisting of white acetate or other fibrous material into a combined filter rod 24 by a method known as the basic filter 18 is illustrated in Figure 5.

From the combined filter rod 24 produced according to Examples 1 and 2, as shown in Fig. 5, a multi-filter cigarette 30 is made in a known manner - in a cigarette production line - by cutting the combined filter rod 24 into filter pieces 26 having a basic filter cover filter and after fitting with the cigarette strain 27, the filter piece 26 is bonded to the cigarette strain 27 with the cuff paper 28. After cutting the paper-wrapped filter piece 26 in two halves 29 in the cover filter, the multi-filter cigarette 30 is finished.

The basic filter pieces 18 formed from the cylindrical body 17 formed in Fig. 4 can be used interchangeably to filter out pipe smoke.

Example 3

Preparation of a cigarette smoke filter by placing the porous structure adsorbent filter additive (perlite or a mixture of perlite and other filter additives, such as activated carbon) of the present invention between two fibrous filter materials in the cigarette body without a binder.

This embodiment of the process of the present invention is illustrated in Figure 7, which shows that the paper or viscose-based filter rod 31 and the cellulose acetate filter rod 33 are cut into pieces 32 and 34 and the porous adsorbent material 35 of the present invention is inserted therebetween. and then wrapping the filter elements with paper 36. Then, in a known manner, the filter rod-adsorbent combination 34, 35, 32 is fitted to the tobacco-filled cigarette strain 40 and the multi-filter cigarette is finished.

The advantage of this method is that since no adhesive is used to bind the adsorbent material 35 introduced into the combined filter rod, the latter does not reduce the active surface area of these adsorbent materials 35 and further reduces the loss of cut material.

Claims (3)

A method for enhancing the efficiency of tobacco smoke filters, in particular cigarette smoke filters, characterized in that a preferred selected variant of perlite having a particle size of 0.1 to 1.0 mm in diameter is used alone or mixed with other porous structure adsorbent filter additives (e.g., activated carbon, silica gel). that (a) evenly spread on a carrier (eg, crepe paper, viscose, cellulose acetate) and cured with adhesive if necessary; obsession b) without a carrier, using a inorganic, organic or plastic-based adhesive to form a slurry and to prepare a basic cigarette filter by a known method, which is also fitted with a top filter to the cigarette body in a known manner to form a multi-filter cigarette. 2. A method for enhancing the efficiency of tobacco smoke filters, in particular cigarette smoke filters, characterized in that a fibrous filter rod (preferably a paper or viscose filter filter) and a fibrous top filter (preferably cellulose acetate) are fitted to the body of the cigarette. 5 based filter rod) without using a binder, a porous structure having a porous structure, preferably of 0.1-1.0 mm in diameter, or a mixture of perlite with other filter additives (e.g., activated carbon, silica gel) and making known procedure with a multifilter cigarette. 3. The method of claim 1, wherein the paper-coated base filter 15, produced without carrier, is applied interchangeably to a pipette for filtering pipette smoke.