ES2370008T3 - IMPROVEMENTS RELATED TO SMOKING AND FILTER ITEMS FOR THE SAME. - Google Patents

Abstract

A filter (1) for smoking articles comprising: a first section (2) comprising a smoke impermeable material having a passage for the flow of smoke extended longitudinally; a second section (8) spaced from said first section by an empty gap (14) and axially aligned with said first section, said second section comprising a core portion (10) circumscribed by an annular portion (12); and ventilation holes (20) positioned in the second section or in the recess; wherein said core portion and annular portion comprises a high pressure drop filter material and the other portion comprises a lower pressure drop material; wherein said passage for smoke flow is longitudinally aligned with said annular portion or core comprising a high pressure drop material.

Description

Improvements related to smoking articles and filter for them

The present invention relates to an improved filter for smoking articles and smoking articles incorporating such a filter. More particularly, it refers to a filter for a cigarette.

For many years, cigarette manufacturers have tried to reduce the amount of smoke constituents delivered to the smoker by filtration. More effort has been made to provide an article for smoking that, when smoked, has a bandwidth and a draft profile with a reduced variation between puffs. The bandwidth of an article for smoking is a ratio of the measure between the tar delivery of a smoked cigarette under the test conditions of the International Standards Organization (ISO) versus the tar delivery of the same cigarette smoked under other conditions , usually in more intense conditions.

Especially, the ISO test conditions involve smoking a cigarette in which the draft volume is 35 ml, the duration of the draft is two seconds, and the interval between puffs is 60 seconds. More intense smoking conditions may include an increase in the volume of draft, an increase in the duration of the draft, a decrease in time between puffs, or some combination of these changes. A lower bandwidth corresponds to a reduced variation in the amount of smoke constituents delivered by a cigarette when smoking under ISO conditions and by the same cigarette smoked under more intense smoking conditions.

The draft profile of a cigarette is the delivery of the constituents of smoke per draft registered against the number of puffs. A draft profile that has a reduced variation between puffs, that is, a relatively flat draft profile, is one in which the delivery of smoke constituents is more consistent at each puff when smoking.

Unfortunately, a flat draft profile is usually not obtained when conventional cigarettes are smoked. It has been known for some time in the tobacco industry that the delivery of the constituents of the smoke particulate phase, or "Total Particulate Matter" (TMP), is not uniform when smoking. Under conditions of smoking on an ISO machine, the "force" per draft - measured by the amount of constituents of the particulate phase of smoke in each draft - is significantly increased from the first draft to the last. This increase in particulate matter in the last puffs is caused by a number of factors, which include a decrease in the efficiency of tobacco cylinder filtration, a reduced level of tobacco cylinder ventilation through cigarette paper - resulting both of the length of the tobacco cylinder that is reduced when smoking - and an increase in the potential of constituents of the particulate phase of the smoke of the tobacco cylinder due to the deposition of constituents of the particulate phase of the smoke from the first puffs of the cylinder.

The ratio of smoke constituents between the first and last puffs on a cigarette varies depending on a number of product design features, including the total performance of smoke constituents for that product. Typically, ratios between 2 and 4 are achieved for "normal" products (having more than 10 mg TPM), between 3 and 5 for "light" (5-10 mg TPM), and between 4 and 6 for "ultra light" (less than 5 mg TPM) under smoking conditions in ISO machine. The high levels of ventilation used in the "light" and "ultra light" products they cause the ratio to increase even if the yields of the constituents of product smoke decrease. This imbalance in the performance of smoke constituents between the first and last puffs in a cigarette can lead to rejection of the product by the consumer due to a perception that the cigarette is too "soft" in the first puffs or too "strong ”In the final puffs. This problem is exacerbated for products that produce a lower level of smoke constituents in the first and last puffs. Accordingly, there is a desire to provide a cigarette with a flatter draft profile that is capable of delivering a similar level of smoke constituents in both first and last puffs.

In addition, it is known that the highest level of smoke constituents delivered in the last puffs represents a significant proportion in the total amount of smoke constituents generated in all cigarette products. Consequently, by reducing the delivery of smoke constituents in the last puffs, the amount of smoke constituents delivered in total will also be reduced.

Accordingly, it is an objective of the present invention to provide a filter for smoking articles that efficiently and effectively reduces the delivery of smoke constituents delivered to a consumer in use.

It is yet another objective of the present invention to provide a filter for smoking articles that is capable of decreasing the bandwidth of an article for smoking and / or that is capable of decreasing the variation in the delivery of smoke constituents between puffs.

EP-A2-0 558 166 describes a cigarette with a ventilated filter. The cigarette filter has two filter sections separated by a central chamber, which contains an adsorbent. The tobacco side filter section achieves a high pressure drop by means of a passage for the flow of smoke permeable smoke, such as a core, which is enclosed by a virtually smoke impermeable coating.

The invention comprises a filter for smoking articles having at least two different sections. A first section comprises an internal area and a surrounding area, the internal area and the surrounding area comprising a passage for the flow of smoke and an area of material relatively impermeable to smoke. The relatively smoke impermeable material has increased the flow resistance when compared to the smoke flow resistance of the smoke flow passage. In one embodiment, the passage for smoke flow and the relatively smoke impermeable material are placed in a core and in annular configuration, the passage for smoke flow forming the core. In an alternative embodiment the passage for the flow of smoke forms the ring and the relatively smoke-impermeable material forms the core of the first section.

The second section comprises a smoke impact zone in axial alignment with the passage for the smoke flow of the first section. The second section of the filter may comprise a core comprising a high pressure drop filter material and a ring comprising a lower pressure drop filter material than the core or vice versa.

In an embodiment of the filter of the present invention, the first and second sections are spaced from each other by means of an intermediate gap.

In one embodiment of the invention, the filter is designed in such a way that the passage for smoke flow of the first section is axially aligned with the core of the second section. In this embodiment, the core of the second section is made of high pressure drop filter material when compared to the ring filter material of the second section. In use, the smoke leaves the passage for the flow of smoke from the first section in such a way that a large portion of the smoke - especially the heavier smoke constituents - impacts the high pressure drop core of the second section. Alternatively, in this embodiment, a block of relatively smoke-impermeable material can be placed in the second section in axial alignment with the exit of the passage for the flow of smoke from the first section such that a large portion of the smoke - especially the heavier constituents of smoke-impacts with the wad of the relatively smoke-impermeable material of the second section. Impact filtration occurs when smoke particles hit a material and are retained by it, so in the embodiments described above, the smoke components that impact on the smoke impact zone of the second section will thus be retained. .

In another embodiment, the invention further comprises ventilation holes circumscribing the second section or circumscribing the space or gap between the first and second section. When the cigarette is smoked, the passage for the flow of smoke from the first section begins to be filled with particulate smoke constituents that condense and are deposited in the passage for the flow of smoke, and for the flow of smoke through it begins to become restricted. This restriction leads to an increase in the pressure drop in the first section. As the pressure drop increases, more air is attracted in the filter through the ventilation holes, thus, as smoked in subsequent puffs, causing a decrease in the variation in the delivery of smoke constituents in subsequent puffs that otherwise it would occur as you smoke due to the known phenomenon of increased delivery of smoke constituents in the last puffs of a smoking article.

Ventilation can be provided by means known to those skilled in the art, such as laser or mechanical drilling.

The filter may further comprise additional sections. Additional filter sections may comprise a conventional filtration material such as, for example, cellulose acetate, polypropylene or paper. The additional filter sections may alternatively or additionally comprise a carbonaceous material for example, activated carbon, resin material for example, amberlite, duolite or the like, and / or catalytic material.

The present invention further provides a smoking article comprising a cylinder of smokable material, a layer circumscribing from the cylinder of smokable material, and a filter according to the present invention attached to the cylinder of smokable material.

The first section of the filter according to the invention is preferably adjacent to the cylinder of the smoking material of the smoking article at a first end and is spaced from the second section of the filter at an opposite end.

The filter of the present invention and the cylinder of the smokable material may be joined together by any means known in the art such as, for example, an external coating. As is commonly known, the outer coating may circumscribe the filter along its length and overlap with the cylinder of the smokable material. The outer coating may be attached to the cylinder coating of the smokable material by conventional means, for example, by adhesive.

In the smoking article of the invention, the filter and the cylinder of the smokable material are preferably in coaxial alignment with each other.

In an embodiment of the smoking article according to the invention, the filter may comprise one or more segments of additional filters. The additional filter segment (s) may be located between the cylinder of the smokable material and the first filter section, and / or may be located in the nozzle of the second filter section.

Aspects and advantages of the present invention will be better understood when the detailed description of the preferred embodiment is taken together with the accompanying drawings, in which:

Fig. 1 is a perspective view of a cigarette with chosen portions shown in cross-sectional view; Y

Fig. 2 is a cross-sectional view of an embodiment of the cigarette shown in Fig. 1;

Fig. 3 is a cross-sectional view of another embodiment of the cigarette shown in Fig. 1;

Fig. 4 is a perspective view of another embodiment of the cigarette shown in Fig. 1;

Fig. 5 is a perspective view of yet another embodiment of the cigarette shown in Fig. 1;

Fig. 6 is a graphic representation of the effectiveness of various embodiments of the invention to reduce the total particulate material, and

Fig. 7 is a graphic representation of the effectiveness of an embodiment of the invention for reducing bandwidth.

While this invention is capable of embodiments in many different forms, multiple embodiments are shown in the figures and will be described in detail below. The present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the illustrated embodiments.

Referring now to Figure 1, the invention comprises a cigarette filter 1 and a cigarette 3 designed to reduce the bandwidth of the delivery of a cigarette in use. The cigarette 3 comprises a tobacco section 18 and a filter 1. The filter 1 comprises a first section 2 comprising an internal area 4 and a first surrounding area 6. In one embodiment, the first section 2 is at the end of the cigarette 3 plus near the tobacco section 18. The diameter of the internal area 4 is preferably between 0.5 and 3.0 mm and between 5 and 10 mm in length. It will be understood that the length of the passage for the flow of smoke will be determined by the length of the filter; the length of the passage for the flow of smoke from the first section, however, will be equal to the length of the first section.

For the filter to function properly, the internal area 4 and the surrounding area 6 must comprise a passage for the flow of smoke and an area that is relatively impermeable to smoke. In the preferred embodiment, the internal area 4 is the passage for the flow of smoke and the surrounding area 6 is impermeable to smoke. In this embodiment, the smoke travels through the passage for the flow of smoke 4 and leaves the cigarette at a high speed. In another embodiment, however, the smoke flow passage may be formed by the surrounding area 6 with the internal area 4 being formed of smoke impermeable material.

The step for the flow of smoke 4 can take a different number of embodiments. For example, the passage for smoke flow 4 can comprise a tube 30, as shown in Fig. 2, or a lower pressure drop material 40 - such as cellulose acetate - than that of the surrounding area 6 , as shown in Fig. 3.

Referring again to Fig. 1, the filter 1 further comprises a second axially aligned section 8 comprising a core 10 circumscribed by a ring 12. The inner core 10 of the second section 8 is axially aligned with the inner area 4 of the first section 2. As can be seen more clearly in Figure 2, the filter 1 further comprises a space or gap 14 located between the first section 2 and the second section 8. The gap 14 may be within the range of 0, 0001 mm to 4 mm in length, but in various embodiments of the invention it may be within the range of 0.1-3.8 mm, or in the range of 0.5-3.5 mm, or in the range of 1 -3 mm, or in the range of 1.5-2.5 mm, and in a particular embodiment of the invention is approximately 2 mm. If the space is too wide, the heavier smoke constituents will diffuse through space 14 between the first and second filter section before impacting on the second section 8, which would negatively impact the effectiveness of filter 1. With the rest of filter 1 , the space 14 is covered in the taco wrap and attached to the rest of the cigarette with a conventional external paper.

The core 10 or the ring 12 of the second section 8 may form an impact zone of material relatively impermeable to smoke. If the passage for the flow of smoke in the first section is the internal area 4, then the impact zone of the second section 8 will be the region of the core 10. The smoke impact section may extend along the entire length of the second section 8, as shown in Figs. 1-3, or as shown in Figure 4, may be a small disk 32 of smoke-impermeable material attached to the end of a regular filter section 34. In the embodiment shown in Figure 4, the smoke would diffuse from behind of the smoke-impermeable material, but the heaviest constituents of the smoke would be removed first by their impact on the small disk 32.

If the passage of smoke in the first section 2 is in the surrounding area 6, then the impact zone of the second section 8 will be the region of the ring 12. As shown in Figs. 1-3, this may be a ring 12 of relatively impermeable material along the entire length of the second section 8, or it could be an annular disk 36 of the same material fixed at the end of the regular filter section 34, such as shown in Fig. 5.

When the core 10 acts as the impact zone, the diameter of the outer ring 12 is preferably 40% of the total diameter of the filter 1, but the filter will function properly, however, as long as the core 10 is wider than the outlet diameter of the passage for the flow of the smoke of the first section 2. Also, when the ring 12 acts as an impact zone, its width should be larger than that of the passage for the flow of the smoke formed by the surrounding area 6.

The length of the second section 8 can be any length to compensate for the desired total length of the filter 1, and is usually about 5 to 50 mm. The second section 8 is generally the cigarette filter nozzle.

In one embodiment, the filter 1 further comprises ventilation holes 20, which may be positioned in the second section 8 or the recess 14.

Filter 1 reduces the release bandwidth in two different ways. First, when the cigarette is being smoked, the smoke passes through the passage for the flow of smoke from the first section 2 and enters the hole 14 at high speed. Due to the short distance between the filter sections 2, 8 and the high speed at which the smoke travels, most of the smoke particles do not disperse before impacting and sticking on the high pressure drop material of the second section 8 opposite the step for the flow of smoke from the first section 2. The heavier smoke particles disperse less than the lighter particles, which leads to less total particulate matter leaving the cigarette. The stronger the cigarette shed, the less smoke dispersion occurs, and the greater the filtration takes place.

The second way to reduce bandwidth involves the use of ventilation holes. As the cigarette is smoked, the tube 4 in the first section 2 is progressively filled with particulate smoke constituents, which increases the resistance to the smoke flowing through the tube 4. This increases the pressure drop across the first section 2, which causes more diluting air to be attracted through the ventilation holes 20 when the smoker inhales. The diluent air enters the recess 14 or the second section 8 through the ventilation holes 20 which circumscribe the second section 8 or the space 14. This also concentrates the smoke in the middle of the recess 14, thereby causing the majority of the smoke impact the core 10, which in the preferred embodiment comprises the impact area of the second section 8.

While it has been described which are believed to be the preferred embodiments of the present invention, those skilled in the art will recognize that other or more changes and modifications can be made without departing from the spirit of the invention, and it is intended to claim all these changes and modifications that enter within the real scope of the invention.

EXAMPLES

Four different embodiments of the invention were tested to determine the amount of total nicotine-free particulate matter in each draft and to determine whether delivery changed as the number of puffs increased. In Examples A and B, the first and second sections were 11 and 14 mm long, respectively, and had a 2 mm gap between the sections. In Examples C and D, the first section was 11 mm long and the second section was 16 mm long, and the gap between the two sections was 0.001 mm. All Examples A, B, C, and D have a tube in the first section with an internal diameter of 2 mm. In Examples A and C, the ring of the second section was made of a high pressure drop material, although in Examples B and D, the ring of the second section was made of a material of lower pressure drop.

Table 1 below and Figure 6 demonstrate the beneficial effect that the invention has on the leveling of the draft profile when compared to a "control" cigarette:

TABLE 1 - Draft Delivery of Wet Particulate Matter Free of Nicotine (in mg)

No. of Draft

Control TO B C D

one

1,068 mg 0.463067 mg 0.443533 mg 0.481333 mg 0.129867 mg

2

1.29256 mg 0.652667 mg 0.454827 mg 0.519467 mg 0.200733 mg

3

1,530667 mg 0.726933 mg 0.625867 mg 0.6452 mg 0.250267 mg

4

1.742667 mg 0.86 mg 0.7856 mg 0.6844 mg 0.216267 mg

5

2,012133 mg 0.904933 mg 0.922667 mg 0.737867 mg 0.4012 mg

6

2,320267 mg 1.098267 mg 1,076907 mg 0.767333 mg 0.340933 mg

7

4,366667 mg 1,272 mg 1.1432 mg 0.9592 mg 0.543333 mg

8

1.402667 mg 1.462667 mg 1,117333 mg 0.737467 mg

In addition, Table 2 and Figure 7 show the reduction in bandwidth that occurs when an embodiment of the invention - Example D - is smoked under different conditions. The more extreme the conditions, the better Example D works compared to the control cigarette. Under the ISO conditions (35 mL draft volume, 2 second draft duration, 60 second draft interval), the difference between the amounts of particulate matter is relatively small. But as the intensity of the total puffs increases, the efficiency of the filter of the invention improves, as demonstrated by the wide difference in TPM between the control and Example D.

TABLE 2 - Delivery of TPM under ISO and other conditions.

Smoking Conditions

Control D

ISO

4.95 mg 4.43 mg

60/2/60

9.16 mg 7.57 mg

2/2/30

11.5 mg 9.93 mg

2/2/30

15.54 mg 11.11 mg

The different embodiments of the invention have a measurable beneficial effect on the decrease in bandwidth, decrease in TPM, and smoothing the draft profile of a cigarette as it is smoked. It is clear that the location of the high pressure drop material and the width of the gap will modify the effectiveness of the invention while still using concepts of the present invention. Such variations are considered to fall within the limits of the

10 present application.

Claims (16)

1. A filter (1) for smoking articles comprising: a first section (2) comprising a smoke impermeable material having a passage for the flow of the smoke extended longitudinally; a second section (8) spaced from said first section by an empty gap (14) and axially aligned with said first section, said second section comprising a core portion (10) circumscribed by an annular portion (12); Y ventilation holes (20) positioned in the second section or in the recess; wherein said core portion and annular portion comprises a high pressure drop filter material and the other portion comprises a lower pressure drop material; wherein said passage for smoke flow is longitudinally aligned with said annular portion or core comprising a high pressure drop material. 2. A filter (1) for smoking articles comprising: a first section (2) comprising a smoke impermeable material having a passage for the flow of the smoke extended longitudinally; a second section (8) spaced from said first section by an empty gap (14) and axially aligned with said first section, said second section comprising a nozzle and a hollow end; ventilation holes (20) positioned in the second section or in the recess; and a smoke impermeable blocking patch (32) attached to the hollow end of said second section; wherein said step for the flow of smoke is aligned longitudinally with said blocking patch.

3.

The filter of claim 1 or 2, wherein said step for the flow of smoke is an opening centrally arranged in said first section.

Four.

The filter of claim 3, wherein said step for the flow of smoke includes a tube inside (4).

5.

The filter of claim 1 or 2, wherein said passage for smoke flow comprises a lower pressure drop material than said smoke impermeable material.

6.

The filter for smoking articles of claim 5, wherein said lower pressure drop material is centrally arranged in said first section.

7.

The smoking article filter of claim 5, wherein said lower pressure drop material circumscribes said smoke impermeable material in a ring / core relationship.

8.

The filter for smoking articles of claim 1 or 2, wherein said ventilation holes circumscribe said second section.

9.

The filter of claim 1 or 2, wherein said ventilation holes are located between said first section and said second section.

10.

The filter of claim 1 or 2, wherein said ventilation holes allow outside air to enter said filter.

eleven.

The filter of claim 4, wherein the amount of air attracted through said ventilation holes increases as said tube is filled with tar.

12.

The filter of claim 1 or 2, wherein said passage for smoke flow is between 5 and 10 mm in length.

13.

The filter of claim 1 or 2, wherein said passage for smoke flow is between 0.5 and 3 mm in diameter.

14.

The filter for smoking articles of claim 1 or 2, wherein the diameter of a core of said second section is approximately 60% of the diameter of said filter.

fifteen.

The filter for smoking articles of claim 1 or 2, wherein there is less than 4 mm between said first section and said second section.

16.

An article for smoking comprising: a cylinder of smokable material;

a coating circumscribing said cylinder of smokable material; and a filter according to any of the preceding claims; the first section of the filter having a first end and an opposite end, said first being joined end to said cylinder of smokable material, and said second section of the filter being separated from said first section through said hollow and axially aligned said opposite end of said first section.