JP2011528900A - Smoking filter - Google Patents

Abstract

  The present invention relates to a smoking article incorporating an improved filter that changes the amount of smoke that is filtered as suction increases. In particular, the filter includes a plurality of paths, at least one first path I extends from the smoking material rod to the mouthpiece of the smoking article, and has high performance for filtering smoke and resisting smoke passage. Includes a section of material. A series of holes at the non-porous interface of these different paths causes the smoke to be drawn between the first path I and one or more second paths II with low ability to filter smoke and resist smoke passage. . If the suction is weak, the smoke is drawn through a small hole between the first and second paths. However, when sucked in strongly, the amount of smoke passing through the small holes is limited by the restrictive orifice effect, thus controlling the level of smoke filtration at different suction forces.

Description

  The present invention relates to a filter for smoking articles such as cigarettes.

  The smoke produced by the burning of smoking articles consists of gas phase components and particulates commonly referred to as “tars”. Various filter structures are known in the art for removing unwanted components from smoke as the smoker inhales smoking articles.

  There are many different filters for smoking articles, such as composite filters containing multiple individual filter sections with different filtration capacities and filters containing different materials such as cellulose acetate and charcoal particles.

  A means aimed at reducing the amount of undesirable components of the smoke that the smoker inhales may consist of diluting the smoke by introducing outside air into the smoking article as the smoker inhales. The most common method of introducing ventilation air is to make holes in the smoking article filter. This method of reducing the concentration of undesirable components has several attendant advantages. In particular, the smoker continues to receive the desired component of smoke and thereby also receives the taste effect. Furthermore, the temperature of the smoke which cold outside air enters into the mouth and throat is lowered, and a more preferable and comfortable smoking effect is achieved.

  One major drawback of ventilating smoking articles in this way is that they excessively dilute the smoke and thus detract from the flavor. Another disadvantage is that as the ventilation increases, the inhalation effort required by the user to be reduced is frustrating for the smoker and smoking is not enjoyable.

  Smokers purchase and use smoking articles to gain efficacy by inhaling the products produced by the burning of smoking material. When ventilation structures are introduced into the smoking article filter, the amount of combustion products received by the smoker is reduced. To make up for this, smokers are known to inhale smoking articles strongly and increase the flow rate in the smoking article to increase the total amount of aerosols (a mixture of smoke and ventilation air).

  The most common way to allow ventilation air to enter the smoking article is to provide a small perforated ventilation hole or conduit on the outer wall of the smoking article. The flow rate of air entering the smoking article through these ventilation holes is not a linear function of the inhalation strength. As the air is strongly inhaled, the proportion of air entering the smoking article through these ventilation holes decreases compared to the proportion of smoke resulting from the burning of the smoking article. Hereinafter, this phenomenon, referred to herein as the “the restricted orifice effect”, is caused by a small diameter ventilation hole, typically less than 1 mm. Smaller holes give greater inertial viscous impedance to the gas drawn through the holes, and this effect becomes smaller as the hole diameter increases. The restricted orifice effect thus limits the amount of dilution air that can enter the smoking article as it is drawn more strongly. The diameter of the ignition end of the smoking article is much larger than the narrow ventilation hole, so the air entering the smoking article via this route is not subject to the restrictive orifice effect. As a result, as the inhalation intensity increases, the amount of ventilation air is limited, but the amount of smoke is not limited, so the concentration of smoke product drawn is also increased.

  The restrictive orifice effect can be eliminated by increasing the diameter of the ventilation hole. However, when the perforations become large, the smoke escapes from these holes. Furthermore, the smoking itself is compromised by the suction strength that the smoker needs to give. It is therefore not easy to construct a smoking article with a filter that is not subject to restrictive orifice effects, especially for filters that are required to provide a high ventilation level.

  In a first aspect of the invention, there is provided a filter for use in smoking articles, the filter including first and second filter paths that operate to impart different filter performance. This filter is configured such that the amount of smoke passing through one path is adjusted by the restrictive orifice effect relative to the other path. The greater the inhalation, the greater the amount of smoke filtration.

  The limiting orifice effect is provided by a plurality of holes. These holes are the only means through which smoke can pass between the first and second filter paths. As the diameter of these holes increases, the amount of smoke passing through the holes is limited. The diameter of these holes is 0.01 mm to 2 mm, preferably 0.1 mm to 1 mm.

  At least one of the paths includes a material capable of filtering smoke. One path may be a gap. Both paths may be made of a material capable of filtering smoke so that the first path has a lower filtration performance than the second path.

  As the suction force increases, the amount of smoke drawn through the first path is limited by the limiting orifice effect, so excess smoke is drawn through the second path.

  This filter may be provided with a ventilation hole, which may be a means such as a deep vent. Apart from this, the filter does not have to be provided with ventilation holes.

  The filter may include a plurality of longitudinally abutting filter sections, at least one of which may be an annular filter section.

  The smoking article to which the filter of the present invention is attached may be a cigarette.

  In a second aspect of the present invention, a smoking article is provided, the smoking article including a filter and a smoking material rod.

  In order that the invention may be more fully understood, embodiments of the invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional side view of an individual filter cigarette filter according to a first embodiment of the present invention. FIG. Fig. 2 shows a route through which smoke passes when sucked weakly through the filter of Fig. 1; Fig. 2 shows a route through which smoke passes when strongly sucked through the filter of Fig. 1. FIG. 6 is a schematic side cross-sectional view of an individual filter cigarette filter according to a second embodiment of the present invention. FIG. 5 is a schematic cross-sectional side view of an individual filter cigarette filter according to a third embodiment of the present invention. 6 is a schematic cross-sectional side view of an individual filter cigarette filter according to a fourth embodiment of the present invention. FIG.

  Described herein is a filter for smoking articles that is configured to utilize the restricted orifice effect to manipulate the passage of smoke and the amount of smoke filtered.

  The “high resistance section” disclosed herein means a section made of a material having a high ability to suppress the passage of smoke. This material can also efficiently filter unwanted components from smoke, for example by having a high density. The terms “high resistance section”, “high filtration efficiency material” and “high resistance material” thus have a common meaning accordingly. On the other hand, “low resistance section”, “low filtration efficiency material” and “low resistance material” and similar terms have low (or do not hold) the ability to suppress the passage of smoke and the efficiency of smoke filtration Used to mean a section consisting of low (or unfiltered) material (or voids). The terms "high" or "higher" and "low" or "lower" used in describing these materials reflect the relative material density, resistance or filtration efficiency, That is, the high resistance section simply has a higher resistance than the low resistance section, and in fact this high resistance section may be less capable of resisting smoke compared to other filters known in the art. Similarly, low resistance sections may actually have a relatively high ability to resist smoke.

  One embodiment of a smoking article including a filter is shown in FIG. Here, the smoking article is a cigarette including a smoking material rod 1 (only part of which is shown) and a filter 2. This filter includes a filter material 3 made of a high resistance material (shaded). As shown in FIG. 1, the filter includes a first section made of a filter material 3a and a second section made of a filter material 3b, and these two sections are in contact with each other in the longitudinal direction.

  As shown in FIG. 1, the section made of the filter material 3 a located at the distal end 4 (far from the mouth end) of the filter has substantially the same diameter as the smoking material rod 1. This ensures that all smoke drawn along the smoking material rod 1 enters the filter material 3a.

  The section consisting of the filter material 3b located at the proximal end 5 of the filter has a small diameter, so that there is a cavity 6 between the filter material and the tipping paper 9 surrounding the filter 2 of the smoking article. This cavity 6 forms a low resistance section. The length of the cavity 6 is a length corresponding to 10 to 90% of the entire length of the filter 2. In some embodiments, the cavity length is 20-80% of the total length of the filter. Preferably the length of the cavity is 30-70% of the total length of the filter. More preferably, the length of the cavity is 40-60% of the total length of the filter. Most preferably, the length of the cavity is 50% of the total length of the filter.

  The filter section 3 b at the proximal end of the mouthpiece is wrapped with a nonporous plug wrapper 7, and a nonporous annular ring member 27 separates the cavity 6 from the distal filter section 3 a. The annular ring 27 is non-porous except for a series of small holes 8 formed therein. As a result, when the smoker inhales the smoking article, the smoke can move from the filter material 3a (high resistance section) to the cavity 6 (low resistance section) only through the hole 8 of the non-porous annular ring member 27. The amount of smoke that passes from the high resistance section through the hole 8 to the low resistance section is limited by the limiting orifice effect when the smoker inhales smoking articles.

  The holes 8 preferably have a diameter of 0.01 mm to 2 mm, more preferably 0.1 mm to 1 mm.

  In use, the smoke passes from the first path I formed in the annular plug wrapper 7 and through the cavity 6 (low resistance section) providing a concentric second path II to the mouth of the filter 3 (high resistance section). Pulled in. More smoke entering the smoker's mouth along the first path I is filtered than smoke entering the mouth via the second path II.

  FIG. 1a illustrates the case where the smoker inhales a smoking article with a weak suction, ie a low negative pressure caused by the smoker inhaling the filter. In this situation, the smoke is sucked along the first path I in the annular plug wrapper 7 through the filter material 3. In addition, as a result of the negative pressure generated by suction with the mouthpiece, some of the smoke is drawn from the filter material through the holes 8 into the cavity 6. As it passes through the second path, the smoke undergoes a lower level of filtration than the smoke that reaches the smoker along the first path.

  However, as suction increases, the restrictive orifice effect limits the amount of smoke that can pass through the hole 8 and enter the second path extending through the cavity 6, as shown in FIG. 1b. Accordingly, the remaining smoke is drawn into the mouth through the above-described first path that is constituted exclusively by the high resistance filter material 3. As a result, the proportion of smoke that passes along the first path as compared to the second path increases as you inhale more, so the smoke that the smoker inhales receives a higher level of filtration as you inhale more.

  As shown in FIG. 1, means for supporting the tipping paper at the proximal end of the filter material 3 is provided. To that end, the band of corrugated paper 10 is arranged so as to wrap a portion along the length of the proximal end of the filter material 3b and to form a series of substantially longitudinal channels. The outer periphery of the corrugated paper 10 is substantially the same as the outer periphery of the distal end section composed of the tobacco rod 1 and the filter material 3a.

  In an alternative configuration, the low resistance section is not a single circumferentially located cavity, but may instead have multiple low resistance sections. An example of such a configuration is shown in FIG. Here, the filter material 3 is shaped to provide a plurality of grooves or channels 28.

  As described above, in the filter structure of FIG. 2, smoke is a series of small holes 29 provided in a non-porous plug wrapper 30 that provides a non-porous interface between the filter material (high resistance section) and the high resistance and low resistance sections. Can only pass through the groove (low resistance section). The restricted orifice effect limits the amount of smoke that passes from the high resistance section to the low resistance section when the smoker smokes a smoking article.

  In another embodiment, the low resistance section is not surrounded by the high resistance section but is surrounded by it.

  FIG. 3 shows another embodiment. In this embodiment, the high resistance section is a cylindrical filter material section 12 that extends the entire length of the filter 13 and has substantially the same diameter as the smokable rod 14.

  The low resistance section is a conical cavity 15 formed by cutting the mouth end of the filter material 12. The length of the cavity 15 corresponds to 10 to 90% of the total length of the filter 13. In some embodiments, the cavity is 20 to 80% of the total length of the filter. Preferably the cavity is 30 to 70% of the total length of the filter. More preferably the cavity is 40-60% of the total length of the filter. Most preferably the cavity is 50% of the total length of the filter.

  The inner surface of the conical cavity is covered with a nonporous coating 16. This may be performed, for example, by directly inserting a non-porous material such as a plastic with a hole formed in advance into a conical shape into the end of the filter material.

  The non-porous lining 16 of the cavity is characterized by having one or more bands of holes 17. The diameter of the hole 17 is preferably 0.01 mm to 2 mm, and more preferably 0.1 mm to 1 mm.

  Under conditions where suction is weak, smoke is drawn through the filter material 12 (high resistance section). Part of the smoke flows through the filter material 12 and flows directly to the mouth end by this filter material providing the first path I, and part of the smoke passes through the hole 17 from the filter material 12 to the conical cavity 15 ( Into the low resistance section), whereby the cavity 15 provides a second path II. As the suction increases, the restrictive orifice effect limits the amount of smoke that can flow through the holes 17 into the second path, so that the remaining smoke generally includes a route comprised of the high resistance section 12. It is sucked into the mouth through the first path. As a result, the proportion of smoke that flows along the first path compared to the second path increases as the suction increases, so overall the smoke drawn by the smoker is at a higher level when the suction increases. Will undergo filtration.

  In other embodiments, the cavity 15 at the mouth end of the filter is not conical, but may be generally cylindrical or, of course, any other suitable shape.

  In another embodiment, the restricted orifice effect reduces the flow of smoke from the low resistance section to the high resistance section.

  Another embodiment is shown in FIG. 4, in which the filter structure shown in FIG. 1 abuts the smokable rod in the opposite direction in the longitudinal direction. In this structure, the distal end of the filter material 18 (high resistance section) far from the mouthpiece has a diameter smaller than the diameter of the smoking material rod 19. As a result, the cavity 20 (low resistance section) exists between the filter material 18 and the chipping paper 21. Thus, smoke will be drawn from the smoking material rod 19 into either the high resistance section 18 or the low resistance section 20.

  The filter material 18 is covered with a non-porous plug wrapper 22. An annular ring 28 is disposed at the mouth end of the cavity 20 and is non-porous except for a series of small holes 23. The diameter of these holes 23 is preferably 0.01 mm to 2 mm, and more preferably 0.1 mm to 1 mm.

  Under conditions of low suction, the smoke is drawn into the low resistance section 20 and then into the high resistance section 18 through the hole 23 in the annular ring 28.

  On the other hand, under conditions of strong suction, the limiting orifice effect limits the amount of smoke drawn from the low resistance section 20 to the high resistance section 18 through the hole 23. As a result, smoke is drawn directly from the smokable rod 19 into the high resistance section 18. The smoke thus flows along the filter into the mouth through a route composed entirely of high resistance material. Under strong suction conditions, the smoke will therefore undergo a high level of filtration.

  In some embodiments where the low resistance section and the smokable rod are in physical contact, there is a non-porous barrier that prevents smoke from entering the low resistance section directly. In this configuration, smoke is drawn from the smoke rod to the high resistance section and then flows into the low resistance section through the small holes as described above. Obviously, these embodiments also include a mechanism that allows smoke to exit the low resistance section and flow into the mouth without further restrictions. Such a mechanism involves the reflow of smoke into the high resistance section.

  In the embodiment of FIG. 4, means are provided for supporting the chipping paper around the cavity 20, which includes a band of corrugated paper 24 surrounding a portion of the length of the filter material 18 and comprising a series of substantially A channel 25 extending in the longitudinal direction is formed. The outer periphery of the corrugated paper 24 is substantially the same as the circumference of the smoking material rod 19.

  The low resistance section need not be a cavity and can include a second filter material that has a lower resistance than the filter material that includes the high resistance section. The smoke will experience a higher level of filtration compared to a configuration where the low resistance section is simply a cavity.

  The entire filter can be surrounded by non-perforated tipping paper provided with a band of circumferentially extending holes that allow dilution air to enter the filter material including the high resistance section.

  Many techniques for providing holes are known in the art. For example, the tipping paper may be perforated before (pre-perforated) or after PP (pre-perforated) construction of the cigarette, and the holes may be formed by rows of pins or on-machine laser (OML) systems. It may be introduced using. In one embodiment, the chipping paper and / or the filter plug paper is perforated with PP or OML so that it does not substantially reach the filter material including the high resistance section.

  Recently, an OML system has been disclosed (British Patent No. 08099865.9) that provides deep penetration (Deep Vent OML; DVOML) in a cigarette filter.

  In one aspect, the chipping paper holes are made by DVOML in another suitable manner and include deep vents that extend substantially toward the center of the diameter of the filter material including the high resistance section. The use of deep vents draws dilution air into the center interior of the filter, which has the effect of modifying the flow of smoke drawn from the smoking material rod. For example, in the preferred embodiment shown in FIG. 1 where the holes 26 include deep vents, the air drawn from these holes enters the filter material 3 near the center of the filter material diameter. This has the effect of concentrating the smoke drawn from the smoking material rod 1 in the weekly region of the diameter of the filter material 3. Therefore, the smoke and air mixture exiting the filter material through the holes 8 contains more smoke than if the holes 26 had reached only the tipping paper 9.

  However, the filter need not be ventilated and may be ventilated by other means, such as through areas of porous tipping paper and plug paper.

  Those skilled in the art will appreciate that the various embodiments of the present invention will be more suitable for different types of smoking articles, especially depending on the required ventilation level. For example, in a low tar product with a high degree of ventilation, it is preferable to limit the hole through which smoke passes upstream (closer to the smoker rod) to maximize its effectiveness There is.

  On the other hand, in the case of high tar products where ventilation is not as important, it is advantageous to place a hole with restricted smoke path towards the mouth end of the smoking article.

  In some embodiments, a filter material that includes high resistance and / or low resistance sections includes a plurality of abutted filter sections of similar or different materials. The filter sections may each be composed of one or a combination of cellulose acetate, polypropylene, paper or other suitable material. The filter section may alternatively or additionally include a carbon-based material such as activated carbon, a fibrous material such as amberlite or duolite, and / or a catalytic material.

  In certain embodiments where the filter includes a plurality of longitudinally abutting and therefore filter sections, the one or more filter sections may include an annular filter section. In this case, the ring may be a cavity or may be composed of a lower resistance filter material, and thus the ring includes a low resistance section.

  In other embodiments, the filter may be composed of multiple filter sections, with one or more annular sections including high resistance sections being used.

  In some embodiments, the filter material may be formed by thermoforming, embossing, crimping or other suitable methods.

  What has been described above is considered to be a preferred embodiment of the present invention. However, one of ordinary skill in the art appreciates that changes and modifications can be made without departing from the scope of the invention.

Claims (16)

  Including first and second paths operable to provide different filtration efficiencies, and these paths are arranged such that the amount of smoke passing through one path is controlled by a restrictive orifice effect relative to the other path Filter for smoking goods.   The filter of claim 1, wherein the restrictive orifice effect is provided by a plurality of holes.   3. A filter according to claim 2, wherein said holes are the only means through which smoke can pass between said first and second filter paths.   4. A filter according to claim 2, wherein the diameter of the holes is sufficiently small so that the amount of smoke passing through the holes is limited as the suction increases.   The filter according to claim 3 or 4, wherein the diameter of the hole is 0.01 mm to 2 mm, preferably 0.1 mm to 1 mm.   6. The filter according to claim 1, wherein at least one of the paths includes a material capable of filtering smoke.   The filter according to claim 6, wherein one of the paths includes a void.   7. The filter of claim 6, wherein both paths comprise a material capable of filtering smoke, and the first path is less capable of filtering smoke than the second path.   9. A filter as claimed in claim 7 or 8, characterized in that the amount of smoke drawn through the first path as it is strongly drawn is limited by the restrictive orifice effect, so that excess smoke is drawn through the second path.   The filter according to any one of claims 1 to 9, wherein a ventilation hole is provided.   The filter according to claim 10, wherein the ventilation hole is formed by a deep ventilation hole.   The filter according to any one of claims 1 to 9, wherein a ventilation hole is not provided.   The filter according to claim 1, comprising a plurality of longitudinally abutting filter sections.   The filter of claim 13, wherein at least one of the filter sections is an annular filter section.   The filter according to claim 1, wherein the smoking article is a cigarette.   A smoking article comprising the filter according to any one of claims 1 to 15 and a smoking material rod.

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