KR100737573B1 - 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 rod (12). It has a tip paper 22 for the purpose. Some grooves are formed in the axial direction from the axial view of the filter plug, and are drilled at the end of the tobacco rod and are continuously formed only at a part of the filter plug length. All grooves are covered with breathable tip paper, which allows the air to be axially ventilated only by the grooves thus formed. The invention also relates to the use of such a filter to reduce the CO / tar ratio as a function of filter airflow.

Filter, Plug Wrap, Groove, CO / Tar Rain

Description

Breathable Smoking Goods {VENTILATED SMOKING ARTICLE}

The present invention relates to, but is not limited to, a smoking article, in particular a cigarette, comprising a filter grooved in the filter circumference.

Various forms of embodiments with such filters are known. US 4,406,294 discloses a cylindrical filter plug, a breathable plug wrap for the filter plug, a cigarette filter grooved in the filter plug circumference, which is formed over a part of the filter length from the mouth end of the filter. However, the grooves in this document are non-breathable. In addition, the cylindrical filter plug and the grooves are attached by breathable tip paper (tipping paper) equipped 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 the circumferential surface of the filter plug including the groove wall in this document is non-breathable because of the non-breathable plug wrap. However, some of the grooves in this document are drilled at the mouth end of the filter plug. 2, 3 and 5 illustrate embodiments that include grooves that are also drilled at the tobacco end. The use of such a filter results in a very low undesirable combustion component and a cigarette with a strong tobacco odor for processing in standard cigarette makers. However, in some of these embodiments, it is required to precisely align the perforated tip wrapper with the circumferential groove, causing problems with manufacturing and quality.

US 4,649,943 discloses a further refinement of this filter, in which the grooves are drilled at the mouth end of the filter. In addition, by providing at least one hole in the groove area to allow air to enter the filter plug from the plug wrap, a filter with improved air distribution in the filter rod is provided. In addition, tip wrappers made of non-breathable materials with breathable regions also contribute to improved air distribution. 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 in the circumference. No plug wrap is mentioned, and the grooves are mainly drilled at the mouth end of the filter.

US 4,362,171 discloses a cigarette filter in which the grooves are not drilled at either the tobacco end or the mouth end of the filter plug and are 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 rod toward the mouth end. Thus, the outside air is simply introduced at a very high speed into the cigarette filter 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 for the filter plug and a center tube formed around the filter plug and positioned at the intersection of the hole and the flow of the groove. This splits the smoke from the tobacco rod 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 in the filter core circumference 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, having a circumference with grooves produced by pleating the material around the actual filter. The plug wrap surrounding the filter 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 a filter element may be used flexibly.

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. The filter thus adjusts the efficiency by lowering the degree of pressure drop in 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 form only a 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 rod 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 smoking articles 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 tobacco smoke with high efficiency while allowing the pressure to drop to an acceptable level.

Further, US-A-3,910,288 discloses filters with filter plugs with grooves formed in the filter plug circumference from a cigarette end of the filter to a 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 a filter is very resistant to breakage so that one groove and / or each groove can be drilled while smoking all smoking articles. Gradually changing the amount of smoke flowing through the groove from a previously determined value to a value of zero, the filter delivers particulate material per intake almost uniformly, 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 an interest in one smoke component, carbon monoxide (CO), but not 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.

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.

By the flow dynamics in the filter of the present invention, the retention of filter material is reduced due to the dependence of known flow linear velocities. In other words, the retention of the filter material decreases as the flow linear velocity increases. 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 present invention, when the cigarette is smoked, the vented air flows through the groove towards the tobacco rod, where it passes back through the filter material towards 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 can be adjusted by appropriately adjusting the intrinsic 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.

For low-delivery products that deliver less than 3 mg of tar, preferably less than 1 mg, it is particularly useful to puncture the tip paper and the non-breathable plug wrap with a laser generator. 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 filter material with an on-line machine increases the degree of air ingress. Thus, the combined ventilation occurs through the grooves and the filter 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.

The experimental results show that the achievable CO / tar ratio has changed according to the filter breathability function, i.e. the CO / tar ratio is reduced by increasing the filter breathability and further compensating for the CO / tar ratio.

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), are added to the filter to provide additional It is also possible to reduce the phase component.

Preferably the filter material is uniform. As used herein, 'uniform' as applied to a filter material means that there is no flow inlet, tube or other element in the filter material. However, the uniform filter material may be composed of different filter materials, such as when the filter section is divided into multiple filters. The uniform filter material has the advantage of being simple to manufacture.

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 circumference.

The depth of the grooves along the rod axis does not necessarily have to be constant. For example, the depth of the groove may deepen towards the tobacco end of the perforated filter. The grooves may also be non-linear, for example threaded or helical, around the filter circumference.

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.

It is apparent that the filter of the present invention may be included as part of a double or triple filter arrangement.

The structure of the tip paper that allows the filter to attach to the tobacco rod may be a 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.

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 rod, 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 shows a portion of a proposed cigarette filter, outlined as a reference sign 10, with a filter member 14 attached to one end of a conventional tobacco rod 12 and a tobacco rod 12. Perspective view. The filter element 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 filter material. Thus, no flow inlet, tube or other means is provided in the filter plug 16. As used herein, 'uniform' as applied to a filter material means that there is no flow inlet, tube or other element in the filter material. However, similar to distinguishing the filter sections described below with respect to FIG. 4, the uniform filter material may be composed of different filter materials 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 is inherently porous / porous or has air holes, particularly in light of tobacco taste. Can be.

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

The groove 20 is axially around the circumference of the filter plug 16 and is provided at a rheologically suitable 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 in the circumference.

The filter element 14 is enclosed in tip paper 22 in the usual manner, and in an embodiment the tip paper is presented with two rows of parallel circumferential 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: the use of non-breathable paper or the use of breathable paper. When non-breathable paper is used 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 rod, i.e. in the reverse direction. The vented air then enters the smoker's mouth via filter plug 16 with smoke from tobacco rod 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 graphically shows 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 indicated above on the CO / tar ratio, wherein Four grooves are symmetrically distributed around the filter plug 16 and are formed on 60% of the length of the filter member 14, starting from the tobacco end.

In the experiment, the air permeability of the filter element 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 the filter member 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 element 14 according to the present 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 threshold by using a filter element 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. Tables 1 to 3 show the results of attaching the filter of the present invention to three types of cigarettes commercially available. 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 experimental results, it is found that the filter of the present invention (named EF) can produce a cigarette with a reduced CO / tar ratio while still showing a pressure drop comparable to that of a standard filter (named SF) by adjusting the airflow. Proven.

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 element 14 of the present invention, in which like parts attached to the tobacco rod 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 element is thus an integrated element.

The subject matter is the same but an alternative embodiment is shown in FIG. 4. However, in this embodiment, the filter element 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 thermoformable plug wraps also allows the thermal formation of grooves in the carbon containing section, opening up opportunities for cigarette designers to choose.

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).

Claims (47)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete Cylindrical filter plug 16 consisting of a uniform filter material, Non-breathable plug wrap 18 surrounding the filter plug 16, A groove formed in the longitudinal direction of the filter plug 16 and spaced apart on the circumference, and recessed in the plug wrap 18, and A tip paper for connecting the filter plug 16 to the tobacco rod 12, All of the grooves 20 are open at the end of the tobacco rod 12 and are continuously formed in only part of the length of the filter plug 16 so that they do not touch the mouth end of the filter plug 16. All grooves 20 are covered with breathable tip paper 22 such that breathable air enters the grooves through the breathable tip paper. A smoking article according to claim 25, wherein the filter material of the filter plug (16) is uniform over the entire length of the filter plug (16). A smoking article according to claim 25, wherein the groove is formed on at least 80% of the length of the filter plug. 29. A smoking article according to any of claims 25 to 27, wherein the length of the groove (20) amounts to about 40 to 70% of the length of the filter plug (16). 29. A smoking article according to claim 28, wherein the length of the groove (20) amounts to 55 to 65% of the length of the filter plug (16). 28. A smoking article according to any one of claims 25 to 27, wherein two to ten grooves (20) are provided. 31. A smoking article according to claim 30, wherein three to five grooves are provided. 32. A smoking article according to claim 31, wherein four grooves are provided. 28. A smoking article according to any one of claims 25 to 27, characterized in that the grooves (20) are symmetrically distributed around the filter plug (16). 28. A smoking article according to any one of claims 25 to 27, wherein the groove (20) is V-shaped or U-shaped. 28. A smoking article according to any one of claims 25 to 27, wherein the groove is 0.5 to 2 mm in depth. 28. A smoking article according to any one of claims 25 to 27, wherein the width of the grooves formed in the circumference is 1 to 3 mm. 37. A smoking article according to claim 36, wherein the width of the grooves formed in the circumference is 1.5 to 2.5 mm. 28. A smoking article according to any one of claims 25 to 27, wherein the filter plug (16) consists of a filter tow made of cellulose acetate. 39. A smoking article according to claim 38, wherein the filter plug (16) contains an additive selected from the group consisting of activated charcoal, zeolite, duolite and fragrance modifying additives. delete delete 28. A smoking article according to any one of claims 25 to 27, characterized in that the tip paper (22) is porous. 28. A smoking article according to any one of claims 25 to 27, characterized in that the tip paper (22) is provided with air holes (24) by mechanical means, electrostatic means, or laser beams. 28. A smoking article according to any one of claims 25 to 27, wherein the degree of aeration of the tip paper (22) is between 45 and 70%. 45. A smoking article according to claim 44, wherein the degree of aeration of the tip paper is between 50 and 70%. delete delete

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