KR20040061044A - Ventilated smoking article - Google Patents

Abstract

The present invention relates to a filter plug (16) which is a smoking article for cigarettes, the filter plug being cylindrical and having a plug wrap (18), a groove (20) dug in the plug wrap, and a filter plug attached to the tobacco body (12). It has a tip paper 22 for the purpose. Some grooves are formed axially from the axial point of the filter plug, are drilled at the end of the tobacco body and are continuously formed only at a portion of the filter plug length. All grooves are covered with breathable tip paper, which allows air to be axially vented only to the grooves formed. In addition, the present invention also relates to the use of such filters to reduce the CO / tar ratio as a function of filter airflow.

Description

Breathable Smoking Goods {VENTILATED SMOKING ARTICLE}

Embodiments of such filters are known in various forms. US 4,406,294 discloses a cylindrical filter plug, a breathable plug wrap to the filter plug, and a grooved cigarette filter formed around a filter plug formed on a portion of the filter length from the mouth end of the filter. However, the groove is non-breathable. The cylindrical filter plug and of course also the grooves are attached by means of breathable tip paper with air holes. The filter is not a composite structure and essentially performs a normal pressure drop in the cigarette.

US 4,256,122 discloses a cigarette filter similar in structure to the above, but here the surrounding structure of the filter plug comprising the wall of the groove is non-breathable because of the non-breathable plug wrap. However, some of the grooves are drilled at the mouth end of the filter plug. 2, 3 and 5 show an embodiment including a groove that is also drilled in the cigarette end. Use of such a filter results in a strong tobacco-scented cigarette, with very low undesirable combustion components and good for processing in standard cigarette makers. However, in some of these embodiments, it is required to precisely align the perforated tip wrapper with the periphery grooves, resulting in problems with manufacturing and quality.

US 4,649,943 shows an additional refinement of this filter, in which grooves are drilled at the mouth end of the filter. In addition, at least one hole is provided in the groove area to allow air to enter the filter plug from the plug wrap, thereby providing a filter with improved air distribution in the filter rod. In addition, a tip wrapper made of a non-breathable material having a breathable area contributes to this. The lining paper (plug wrap) is non-breathable but is equipped with air holes.

DE-PS 21 07 850 also discloses a filter tip with a longitudinal groove around it. No plug wrap is mentioned, and the groove is first drilled at the mouth end of the filter.

US 4,362,171 discloses a grooved cigarette filter which is not drilled at either the tobacco end or the mouth end and is formed only at the center of the filter plug. Each groove is provided with a hole, which guides aeration along the length of the filter body toward the mouth end. Therefore, the outside air is simply introduced into the cigarette filter at a very high speed, without the risk of clogging due to pressure and / or loss of pressure on the lips.

US 4,343,319 discloses a similar cigarette filter with a smoke-impermeable wrapper around the filter plug and a center tube formed about the filter plug and positioned at the intersection of the holes and the flow of the grooves. This splits the smoke from the tobacco body into two branches. One branch flows in the central tube and the other branch flows in the filter material. The presence of a central tube and an interconnecting passage makes filter manufacture more challenging.

DE 30 48 905 A1 also discloses a non-breathable wrapper for the filter core and a cigarette filter with grooves around the filter core which are formed along the entire length of the filter core. Such a filter can be manufactured more easily since there is no need to change the manufacturing method.

GB 2102271 is known for cigarette smoke filters, with grooves created by pleating the material surrounding the actual filter. The plug wrap surrounding the filtration material is smoke aeration. Grooves are provided between the plug wrap and the corrugated material and between the tip wrapper and the corrugated material. The tip wrapper is provided with air holes. Such filter components may be used flexibly in many places.

GB 2 089 641 A discloses a cigarette filter with a hollow tube in the center, which is formed from one end of the filter to the filter material. The filter core is wrapped in a nonporous wrapper, the filter plug and the wrapper having at least one groove, which is formed longitudinally from one end of the filter plug. In this case, the filter adjusts the efficiency by performing a low pressure drop of the normal cigarette. The production of hollow tubes increases the requirements for manufacturing.

GB 2 136 669 A also discloses a cigarette filter with a filter plug surrounded by smoke breathable material. The filter has longitudinal pleats, which are perforated at one end of the filter and formed longitudinally from one end of the filter to the other, but not exceeding the entire length of the filter plug, smoke breathable wrapper Form an outer groove. The smoke breathable wrapper has a coating means, which makes the smoke non-breathable in areas which are formed only in part of the length of the groove, and distinguishes the grooved area of the smoke breathable wrapper from the corresponding end of the filter.

GB 2 095 093 A discloses a filter plug wrapped in a nonporous wrapper and a grooved filter formed at a certain distance from one end of the filter to the other. The grooves can be drilled towards the atmosphere and can be arranged to form up to the mouth end or the cigarette end of the filter. It is also possible to alternately arrange the grooves starting at the mouth end and the cigarette end. The filter is secured to the tobacco body by a long, thin material to prevent the opening of the air holes in the grooves from breaking.

US-A-3,752,165 proposes a filter for a smoking article with a filter plug wrapped in thin, porous wrapper paper. A plurality of grooves are formed in the wrapper paper and also in the filter material at one end of the filter. The groove is formed from one end of the filter to the point just before the opposite end and is surrounded by a smoke-breathable plug wrap. The groove is formed from one end of the filter to a point slightly away from the other end. Such a filter can be used to remove tar from cigarette smoke with high efficiency while dropping the pressure to an acceptable level.

Further, US-A-3,910,288 discloses filters with filter plugs with grooves formed around the filter plug from the tobacco end of the filter to the position before the mouth end of the filter. The grooves are formed in a rigid plastic wrapper surrounding the filter material. At one end of each groove is a hole that allows connection with the filter material. Filter breathability is not provided.

Such filters are very resistant to destruction so that one groove and / or each groove can be drilled while smoking a smoking article. By slowly varying the amount of smoke flowing through the grooves from a previously set value to a value of zero, the filter achieves a nearly uniform particulate mass transfer per inhalation while increasing the efficiency of the filter to a relatively constant amount.

Finally, US-A-3,596,663 proposes a filter for a smoking article with a filter plug with grooves of undefined length. The filter wrapper and lining paper are in each case porous and / or porous. The breathable wrapper is pleated to increase the size of the breathable surface, thereby simplifying the passage of air from the breathable wrapper paper to the filter material of the filter plug. The breathable filter thereby significantly reduces the air flow to the filter medium.

Thus, in summary, cigarette filters have been provided in the last few years with grooves that direct smoke and / or air in a direction that depends on the location and length of the grooves and the porosity and / or breathability of the tip paper or filter wrapper paper. I can tell. In this way, dilution of the smoke, disturbance of the smoke in the mouth, and directing the aeration of air and smoke, and other effects can be achieved.

In recent years, there has been interest in one smoke component, carbon monoxide (CO), but without much income and economic filters are not yet known. Attempts have been made to reduce the CO content in smoke below a certain maximum, particularly in the context of new legal regulations that regulate the maximum CO tolerance in cigarette smoke in cigarettes.

The present invention relates to smoking articles, and in particular, to smoking articles comprising a filter grooved around the filter, but not limited to cigarettes.

In order that the present invention may be more clearly understood and the results may be more readily performed, reference will be made to the following examples and schematic drawings.

1 shows a perspective view of a filter attached to a tobacco body, partially wrapped with tip paper.

2 is a graph of CO / tar as a function of filter breathability for a filter and a comparative filter according to the present invention.

3 shows an embodiment of a filter containing particulate additive.

4 shows another embodiment of a filter containing particulate additive.

1 is a perspective view showing a portion of a proposed filter cigarette, outlined as a reference numeral 10, with a conventional tobacco body 12 and a filter component 14 attached to one end of the tobacco body 12. to be. The filter component 14 consists of a cylindrical filter plug 16 consisting of cellulose acetate tow uniformly distributed over the entire volume of the filter plug 16 as filtration material. Thus, no flow inlet, tube or other means is provided in the filter plug 16. As used herein, 'uniform' as applied to a filtration material means that there is no flow inlet, tube or other element in the filtration material. However, the uniform filtration material may be composed of different filtration materials, such as the division of filtration sections described below with respect to FIG. 4, and in no case include flow inlets, tubes, or the like.

The filter plug 16 is covered with a non-breathable plug wrap 18, but in other embodiments (not shown) the filter plug may be inherently porous / porous or equipped with air holes, especially considering tobacco taste. have.

A groove 20 is stamped around the filter element 14, in which four grooves 20 are symmetrically distributed around the filter element 14. The groove 20 is formed to the tobacco body side end of the filter element 14, which is drilled to allow flow between the groove 20 and the tobacco body 12 to be connected.

The groove 20 is axially circumferentially around the filter plug 16 and at a rheologically appropriate distance from the mouth end of the filter component 14, ie both air and smoke from the groove 20. End at a distance that cannot reach the tip of the mouth at (14).

The researchers demonstrated that the axial length of the grooves 20 should be shorter than 80% of the length of the filter plug 14. About 60% is preferred.

The depth of the grooves 20 is approximately 1.5 mm, the cross section is U-shaped and the width is approximately 2 mm at the outer circumference.

The filter component 14 is wrapped in tip paper 22 in the usual manner, and in the embodiment the tip paper is presented with two rows of parallel ambient air holes 24. More or fewer rows of air holes may also be provided, or the tip paper 22 may be porous in nature. The porosity and / or number and size of the air holes 22 are only necessary to ensure the desired degree of breathability.

With regard to the arrangement of the plug wraps 18, in principle there are two possibilities: using non-breathable paper or using breathable paper. In the case of using non-breathable paper as the plug wrap 18, the aerated air flows through the air holes 24 into the grooves 20 and then moves from the grooves 20 toward the tobacco body, ie in the reverse direction. The vented air then enters the smoker's mouth via filter plug 16 with smoke from tobacco body 12.

If the plug wrap is inherently porous or breathable by being provided with air holes, an adjustable portion of the vented air is passed by the passage through the breathable plug wrap into the filter and into the smoker's mouth. This is combined with the air flow through the grooves 20. In this way the dilution of the smoke can be adjusted by air aeration in two parts, ie first along the groove 20 by aeration through the tip paper 22 and secondly via the plug wrap 18. By venting directly into the filter plug 16.

If desired, additional short grooves can be made in the outer surface of the tip paper 22 that are only drilled at the mouth end of the filter 14. They have no rheological function and are not connected to the ventilation zone 24 and merely serve to remind the smoker of the presence of a groove in the filter element 14.

FIG. 2 shows a graph of the effect of a filter according to the invention having a conventional cellulose acetate filter tow, a non-breathable plug wrap and four grooves 20 of the size shown above on the CO / tar ratio, wherein 4 The grooves are symmetrically distributed around the filter plug 16 and are formed on 60% of the length of the filter component 14, starting from the tobacco end.

In the experiment, the air permeability of the filter component 14 was changed from 0 to a maximum of about 70%. For products of 3 mg or less, it is necessary to use not only mechanical laser apertures but also perforated tip papers in order to obtain the required aeration. This increased aeration also helps to lower the pressure of cigarettes. The CO / tar ratio reduction obtained is balanced with the amount of aeration used.

In Fig. 2, the circle symbol represents a value measured for a conventional filter made of monoacetate filter tow without making a groove, and the square symbol is a filter component according to the present invention having the same structure and size as the comparative filter described above. The value measured about (14) is shown.

The filter component 14 according to the invention reduces the CO content in the smoke compared to the delivered tar, thereby lowering the CO / tar ratio from about 1.4 to about 0.7, whereas CO / tar when only vented without using a groove It will be appreciated that the ratio can be reduced to only about 1.12.

Thus, the CO / tar ratio can be reduced below the limit by using a filter component 14 according to the present invention to appropriately select the appropriate degree of aeration of the tip paper 22 and adjust it in a new way.

Further studies of the cigarette with a filter according to the invention have also confirmed these results for different tobacco blends in the tobacco section of the cigarette. In Tables 1 to 3, the results of attaching the filter of the present invention to three commercially available cigarettes are shown. Corresponding cigarettes with conventional filters yielded tar amounts of about 10 mg, 6 mg and 3 mg, respectively. Measurements were performed according to DIN and ISO standards.

The filter used for this measurement was a groove with the following parameters: four grooves, 17 mm long, about 1.5 mm wide and 0.5 to 1 mm deep. The plug wrap was non-breathable and not further breathable.

From the results of the experiment, the filter of the present invention (named EF) can produce a cigarette with a significantly reduced CO / tar ratio while showing a pressure drop comparable to a cigarette with a standard filter (named SF) by adjusting the aeration rate. Proved to be.

SF EF EF EF EF EF Pressure drop of filter (mm) (H ₂ O) 72 76 76 74 73 72 Filter aeration 22.6 0.0 12.0 51.8 57.2 62.1 Tar (mg) 10.25 12.4 11.7 8.8 7.2 5.7 CO (mg) 11.21 13.3 12.1 6.7 4.5 2.9 Pressure drop of cigarette (mm) (H ₂ O) 117 137 121 104 93 93 CO / tar 1.09 1.07 1.03 0.76 0.63 0.51

SF EF EF EF EF Pressure drop of filter (mm) (H ₂ O) 108 90 89 91 89 Filter aeration 43.0 0.0 50.6 58.3 69.1 Tar (mg) 5.6 11.4 7.8 6.1 4.3 CO (mg) 6.7 13.1 5.8 3.5 1.8 Pressure drop of cigarette (mm) (H ₂ O) 112 144 114 110 107 CO / tar 1.19 1.15 0.74 0.57 0.42

SF EF EF EF EF Pressure drop of filter (mm) (H ₂ O) 124 100 98 99 98 Filter aeration 56.7 0.0 45.2 51.1 62.5 Tar (mg) 3.33 8.8 6.3 5.2 4.4 CO (mg) 4.24 11.3 5.4 3.6 2.6 Pressure drop of cigarette (mm) (H ₂ O) 107 144 125 121 120 CO / tar 1.27 1.28 0.86 0.69 0.59

FIG. 3 shows a cross section of the filter component 14 of the present invention, in which like parts attached to the tobacco body 12 are numbered according to FIG. 1. The plug wrap 18 used to cover the filter plug 16 includes an activated carbon particulate containing portion attached to the region 26. A groove 20 is formed in the plug wrap 18 after the plug wrap wraps around the filter plug 16. The filter component is thus an integrated component.

The subject matter is the same but an alternative embodiment is shown in FIG. 4. However, in this embodiment, the filter component comprises three sections: a groove section in which grooves 20 are formed on the surface, and a spotted carbon section 28 comprising activated carbon particles dispersed in cellulose acetate tow. , And the usual cellulose acetate tow section 30. These three sections can be joined together by one moldable plug wrap to create a groove of the groove section. Alternatively, grooves are formed in the surface of either the self-sustaining uncovered acetate (NWA) section or the plug wrap covering the cellulose acetate section. The three sections are then arranged together and then overlaid with additional plug wrap (not shown).

3 and 4 avoid the problem of forming grooves in the filter section containing the particulate material, which may adversely affect the particulate material when contacted with the component being heated during molding. However, the use of a thermoformable plug wrap also allows the thermal formation of grooves in the carbon containing section, opening up a choice for cigarette designers.

In addition, the presence of additional substances may affect other vapor phase components, which may be particularly advantageous for the selective removal of some of the compounds in the Hoffman analysis list (see Hoffmann, D., Hoffmann, I., " Tobacco Smoke Components ", Beitrage zur Tabakforschung International 18 (1998) 49).

It is an object of the present invention to produce a smoking article, in particular a filter of a cigarette, which allows for an effective, specifically adjustable CO content reduction in smoke, relative to other ingredients such as tar and nicotine.

This object is achieved according to the invention by the features of claim 1.

Suitable embodiments are defined according to the characterizing content of the dependent claims.

Due to the flow dynamics in the filter of the present invention, the retention of the filtration material is reduced depending on the well-known decrease in the flow linear velocity, i.e. the retention decreases as the flow linear velocity is increased. Due to the fact that the amount of CO is not affected by the filter material, the CO / tar ratio is reduced.

When a non-breathable plug wrap is used in the filter according to the invention, air vented throughout the groove towards the tobacco body when smoking the cigarette flows there through the filtration material and back to the smoker's mouth.

As an alternative, it is also possible to have air holes by using a plug wrap which is inherently porous or breathable. Some of the vented air flows through this passage and flows from the breathable plug wrap to the filter and into the smoker's mouth. This part can be adjusted by appropriately adjusting the intrinsic porosity or artificial porosity of the plug wrap, which means that the pressure drop / smoking kinetics and CO / tar ratio can be improved.

As another alternative, porous or breathable plastic sheet or foil may be used as the plug wrap material.

Punching the tip paper and the non-breathable plug wrap with a laser generator is particularly useful for low-delivery products that deliver less than 3 mg, preferably less than 1 mg tar. For such low delivery products it may be advantageous to provide two rows of air holes, one row upstream of the axially formed groove and the other row downstream of this hole. Punching both the plug wrap and the underlying filtration material with an on-line machine increases the air ingress. Thus, the combined ventilation occurs through the grooves and the filtration material.

Synthetic plug wraps or thermoformed plug wraps such as those described in British Patent No. 2058543, 2056841 or 2134365 may be particularly suitable as the heat moldable plug wraps of the present invention.

Experimental results show that the CO / tar ratio achievable with the filter breathability function has changed, i.e. by increasing the filter breathability and further correcting the parameters for the CO / tar ratio, the CO / tar ratio is reduced.

In a preferred embodiment, between two and ten grooves are provided because using only one groove leads to a distribution of aeration in the highly asymmetrical smoke that can interfere with smoking. More than 10 grooves complicate the manufacturing process and make it difficult to provide enough space for the proper flow cross section of each groove. Good results were achieved when four grooves were used.

The cross section of the groove may be V-shaped, or preferably U-shaped, because of manufacturing and rheological advantages.

Once the proper number of grooves, the appropriate depth, the width and the length have been chosen, the filter properties of the cigarettes produced can be adjusted to the desired properties.

Any filter material commonly used may be used as the filter material in which one or several such materials may be used. Preferably a tow of conventional cellulose acetate is used. To cure the filter, conventional techniques such as, for example, adding triacetin or Tegda to the filter tow are used.

In addition, additives such as activated charcoal, zeolites, fragrance modifiers or ion exchange resins such as porous particulate salts of weakly basic anion exchange resins, such as duolites (see US Pat. No. 3,716,500 or 3,943,832), may be used to reduce other vapor phase components. It may also be added.

Preferably the filtration material is homogeneous. As used herein, 'uniform' as applied to a filtration material means that there is no flow inlet, tube or other element in the filtration material. However, as the filter is a multiple filter when separating the filtration sections, the uniform filtration material may be composed of different filtration materials. The uniform filtration material has the advantage of being simply produced.

Preferably the additive is present in the grooveless part of the filter. This prevents the additives from thermally decomposing at the time of forming to create grooves.

According to a preferred embodiment, the grooves are formed shorter than 80% of the filter length, and good results are obtained when about 60% are formed.

The depth of the grooves should be in the range from 0.5 to 2 mm, preferably at about 1 mm to achieve an appropriate flow volume.

In view of this criterion, the width of the grooves should be 1 to 3 mm, preferably 1.5 to 2.5 mm, as measured at the filter perimeter.

The depth of the grooves along the body axis does not necessarily have to be constant. For example, it may be deeper towards the tobacco end of a perforated filter. The grooves may also be nonlinear, for example threaded or helical around the filter.

In some cases, it may be necessary to add additional grooves radially around the filter to the filter. This groove is connected to the axis of the groove. Such radial grooves are useful in that they are located just below the vent area of the tip paper to enhance the vent effect. If the vent area is larger, it may be necessary to use two or more radial grooves.

The filter of the present invention may be explicitly included as part of a double or triple filter arrangement.

The structure of the tip paper that allows the filter to be attached to the tobacco body can be any conventional structure provided to allow for aeration. This can be achieved by using porous, inherently breathable, tip paper, or by making air holes with mechanical or electrostatic means or laser beams.

Claims (24)

A filter plug 16 made of uniform filtration material, a plug wrap 18 surrounding the filter plug 16, a groove formed around the filter plug 16 in the longitudinal direction, and a filter element 14; A smoking article incorporating a filter element (14) comprising breathable tipping paper that connects a tobacco rod (12) to each other, wherein several grooves (20) are drilled on one side of the tobacco body (12). And continuously formed only over a portion of the length of the filter element 14 so that it does not reach the mouth end of the filter element 14, and each groove is arranged in the axial direction from the filter axis point of view and is formed in the axial direction groove 20. Passing air enters over the breathable tip paper and the groove formed by any mouth end is not vented. A smoking article according to claim 1, wherein the filtration material of the filter plug is uniform over the entire length of the filter plug. The smoking article according to claim 1, wherein the groove (20) is formed on at least 80% of the length of the filter plug (16). 4. Smoking according to any one of the preceding claims, characterized in that the length of the grooves 20 is about 40 to 70% of the length of the filter plug 16, specifically about 55 to 65%. article. 5. Smoking article according to claim 4, characterized in that the length of the groove (20) amounts to 55-65% of the length of the filter plug (16). Smoking article according to one of the preceding claims, characterized in that two to ten grooves (20) are provided. 7. A smoking article according to claim 6, wherein three to five grooves are provided. 8. A smoking article according to claim 7, wherein four grooves are provided. 9. A smoking article according to any one of the preceding claims, characterized in that the groove (20) is symmetrically distributed on the outer periphery of the filter plug (16). 10. A smoking article according to any one of the preceding claims, characterized in that the groove (20) is V-shaped or U-shaped. The smoking article according to claim 1, wherein the groove has a depth of 0.5 to 2 mm. 12. A smoking article according to any one of the preceding claims, characterized in that the width of the grooves (20) formed on the outer periphery is between 1 and 3 mm. 13. A smoking article according to claim 12, wherein the width of the grooves formed in the outer circumference is 1.5 to 2.5 mm. A smoking article according to claim 1, characterized in that the filter plug (16) consists of a filter tow made of cellulose acetate. 15. A smoking article according to claim 14, wherein the filter plug (16) contains additives such as activated charcoal, zeolite, duolite or fragrance modifier additives. 16. A smoking article according to any one of the preceding claims, wherein the plug wrap (18) is non-breathable. The smoking article according to claim 1, wherein the plug wrap is porous and / or has air holes. 18. A smoking article according to any one of the preceding claims, characterized in that the tip paper (22) is porous. 18. A smoking article according to any one of the preceding claims, characterized in that the tip paper (22) is provided with an air hole (24) by mechanical or electrostatic means or by a laser beam. 20. A smoking article according to any one of the preceding claims, characterized in that the degree of aeration of the tip paper (22) is 30 to 80%, more specifically 40 to 70%. A smoking article according to claim 20, wherein the degree of aeration of the tip paper is between 40 and 70%. 22. A smoking article according to any one of the preceding claims, characterized in that an additional short groove is provided at the mouth of the filter plug (16) to indicate the presence of the groove (20). A cylindrical filter plug 16 made of filtration material, a plug wrap 18 for the filter plug 16, a groove 20 formed longitudinally along the filter plug 16 and dug in the plug wrap 18, and A smoking article comprising a tip paper for connecting the filter plug 16 to the tobacco body 12, wherein all the grooves 20 are open at the end of the tobacco body 12 and are continuous only at a portion of the length of the filter plug 16. Smoking article characterized in that it is not in contact with the mouth end of the filter plug (16), and all the grooves (20) are covered with breathable tip paper (22). Use of a smoking article according to any one of claims 1 to 23 for reducing the CO / tar ratio as a function of filter breathability.