TW201605360A - Filter-tipped cigarette - Google Patents

Abstract

This invention provides a technology to make tar contamination of end face of mouthpiece of a filter-tipped cigarette inconspicuous, and restrain hardness of the filter from becoming insufficient. This invention provides a filter-tipped cigarette comprising a cigarette rod containing shredded tobacco and a filter connected to an end of the cigarette rod via tip paper, wherein the filter has a mouthpiece end section and a front part section, the mouthpiece end section is arranged in the mouthpiece end and comprises a fiber bundle formed in cylindrical shape and a first smoke passage penetrating the fiber bundle in the longitudinal direction, the front part section being continuously arranged in the front end of the mouthpiece end section and comprising a fiber bundle formed in cylindrical shape and a second smoke passage penetrating the fiber bundle in the longitudinal direction, the first smoke passage having a flow passage cross sectional area larger than the flow passage cross sectional area of the second smoke passage.

Description

Cigarette with filter

The present invention relates to a smoking article with a filter attached thereto.

The cigarette with the filter is tar, nicotine, CO (carbon monoxide), etc. by adjusting the balance between the dilution of the air generated by introducing the ventilation air from the vent hole formed in the outer peripheral portion of the filter and the filtration through the filter material. Control (adjustment) of ingredients in cigarette smoke.

However, since CO is a gas phase component, it cannot be filtered through a filter material, and the concentration in the smoke is reduced by dilution of air. On the other hand, the tar is reduced by two factors of filtration of the filter material and dilution of the air. Therefore, in the design method of the cigarette with the filter, there is a case where the low filtration and high dilution design is performed, that is, the filtration ratio of the filter material is lowered, and the dilution ratio is increased. According to this low filtration and high dilution design, the CO ratio with respect to tar can be lowered, and the smoking mouthfeel can be increased, and the effect of improving the flavor can be expected.

In order to achieve a low filtration and high dilution design, various methods are employed. For example, it is known that the fiber diameter of the filter material is made thicker and the density is reduced, so that the ventilation resistance of the mainstream smoke is lowered, or the diameter of the vent hole through which the ventilation air flows in is increased to increase the dilution ratio. technique. However, by The limitation of the circumferential length of the cigarette, the length of the filter, the material used for the filter material, and the like, causes the limit of the ventilation resistance of the filter material to be lowered by the above-described method.

Therefore, there has been proposed a design method of arranging a section having no filtering function of mainstream smoke in a partial section of the filter, for example, a central hole filter having a through hole at a center portion of the shaft, or a portion of the filter The design method of low filtration and high dilution is realized by forming a concave portion or a chamber in the interval.

(previous technical literature)

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 5-23158

However, the filterless section which does not have the filtering function of the mainstream smoke is simply provided in the partial section of the filter, and although the low filtration and high dilution of the mainstream smoke can be achieved, the following problems may occur. For example, when a central hole filter is used, there is a problem that tar is likely to locally adhere to the periphery of the center hole in the end face of the mouthpiece, and the tar contamination of the mouth end face after smoking is conspicuous. On the other hand, when a concave portion is formed on the suction end side of the filter or a chamber is formed in the intermediate portion, the hardness of the filter is likely to be insufficient.

The present invention has been made in view of the above problems, and an object thereof is to provide a tar stain of a suction port end face in a cigarette with a filter. A technique in which the dyeing is not easily noticeable and the hardness of the filter is insufficient.

In order to solve the above problems, the present invention forms a through-path for the mainstream smoke flow in the suction port end section disposed at the suction end of the filter and the front section of the front end connected to the suction port end section, and the suction port is provided. The cross-sectional area of the flow path of the through-path in the end section is larger than the cross-sectional area of the flow path of the through-path of the front section.

More specifically, the filter-attached cigarette of the present invention comprises: a tobacco rod comprising shredded tobacco; and a filter connected to the end of the tobacco rod through the outer layer paper; wherein the filter has a mouth end region The segment is a suction port end section disposed at the suction end, and is provided with a fiber bundle, the fiber bundle is formed with a through-path for the mainstream smoke flow along the axial direction; and the front section is connected to the suction port a front section of the front end of the end section, and a fiber bundle is disposed, the fiber bundle is formed with a through passage for the mainstream smoke to flow along the axial direction; the cross-sectional area of the through passage in the suction end section is larger than the front section The section of the section of the section is larger.

According to the present invention, in the cross-sectional area of the through-passage of the suction port end section, the flow path in the axial direction is not in the axial direction of the cross section of the front section which is overlapped with the front section in the axial direction. The flow rate (flow rate) of the mainstream smoke flowing in the region on the outer peripheral side of the overlap is relatively slow (less). Thereby, when the mainstream smoke is sucked into the oral cavity from the rear end of the through-passage of the suction port end section, the frequency (opportunity) at which the suction nozzle end face of the filter comes into contact with the mainstream smoke can be reduced. As a result, it is not easy to cause local tar adhesion of the periphery (edge portion) of the through passage of the suction port end surface. Therefore, the filter can be suppressed The tar on the end face of the suction port is contaminated and makes it difficult to stand out. Further, according to the present invention, since it is not necessary to provide a section such as a chamber and a recess in the filter, it is possible to suppress the occurrence of insufficient hardness of the filter.

Further, in the present invention, the length of the mouth end section may be shorter than the length of the front section. With the above configuration, it is possible to more reliably suppress the deterioration of the hardness of the filter.

Further, in the invention, each of the suction end section and the front section may be coaxially arranged. According to the above configuration, the tar contamination of the suction port end surface of the filter can be made more conspicuous and less conspicuous.

Further, in the present invention, a tobacco overflow suppressing means for suppressing entry of the shredded tobacco into the filter may be provided at an end portion of the filter. According to the above configuration, the tobacco rod of the tobacco rod can be appropriately prevented from entering the filter.

Further, in the present invention, a filter material for filtering a fiber bundle of mainstream smoke is disposed at an end portion of the filter, and the filter material may have the above-described tobacco spill suppressing means. According to the above configuration, the material cost of the filter can be reduced, and the manufacturing process of the filter can be suppressed from becoming complicated.

Further, in the present invention, the outer layer paper is formed with a vent hole for introducing the outside air into the filter and diluting the mainstream smoke, and the vent hole may be disposed in the filter upstream of the suction port end section. Side position. According to the above configuration, there is an advantage that the mainstream smoke is easily brought closer to the center side in the front section.

Further, the means for solving the problems of the present invention can be used in combination as much as possible.

According to the present invention, it is possible to provide a technique in which the tar contamination of the end face of the suction port is not easily conspicuous and the hardness of the filter is insufficient.

1, 1A, 1B, 1C‧‧ ‧ cigarettes

2‧‧‧Tobacco stick

3‧‧‧ outer paper

4, 4A, 4B, 4C‧‧‧ filter

21‧‧‧ cut tobacco

22‧‧‧Roll paper

31‧‧‧ vents

41, 44, 410‧‧‧ filter materials

42, 43, 430‧‧‧ central hole filter

42a‧‧‧First central hole

43a‧‧‧Second central hole

45a‧‧‧ third central hole

46a‧‧‧Fourth Central Hole

100‧‧‧ manufacturing equipment

110‧‧‧ storage container

120‧‧‧Adding unit

130‧‧‧Forming device

140‧‧‧Packing device

150‧‧‧Filter fiber

430a‧‧‧Central hole

S0‧‧‧ Charcoal filter section

S1‧‧‧Filter section

S2‧‧‧Segment

S3‧‧‧ suction end section

S4, S5‧‧‧ central hole section

Fig. 1 is a longitudinal sectional view showing a cigarette of the first embodiment.

Fig. 2 is a perspective view of the cigarette of the first embodiment.

Fig. 3 is a view showing a manufacturing apparatus of the central pore filter of the first embodiment.

Fig. 4 is a longitudinal sectional view of a filter of a comparative example.

Fig. 5 is a view conceptually showing the tar contamination of the suction port end face of the filter of the comparative example.

Fig. 6 is a view showing another aspect of the position where the vent hole is disposed in the filter of the first embodiment.

Fig. 7 is a longitudinal sectional view showing a cigarette of Modification 1.

Fig. 8 is a longitudinal sectional view showing a cigarette of Modification 2.

Fig. 9 is a longitudinal sectional view showing a cigarette of Modification 3.

Hereinafter, an embodiment of the cigarette with a filter of the present invention will be described in detail with reference to the drawings. The dimensions, materials, shapes, relative arrangements, and the like of the constituent elements described in the present embodiment are not limited to the above-described conditions unless otherwise specified.

<Embodiment 1>

Fig. 1 is a longitudinal sectional view showing a cigarette of the first embodiment. Fig. 2 is a perspective view of the cigarette of the first embodiment. The cigarette 1 is provided with a tobacco rod 2, and a filter-attached cigarette that is connected to the filter 4 of one end of the tobacco rod 2 through the outer layer paper 3.

The tobacco rod 2 is formed by winding the shredded tobacco 21 into a roll (22) in a roll paper 22, and is also called a "single roll". The filter 4 is a member for filtering the smoke component contained in the mainstream smoke when the mainstream smoke generated during smoking of the cigarette 1 passes, and is formed into a cylindrical shape having substantially the same diameter as the tobacco rod 2.

The filter 4 is wound by the outer layer paper 3, and is connected to the rear end side of the tobacco rod 2 through the outer layer paper 3. The outer paper 3 is connected (joined) by integrally winding the end of the tobacco rod 2 and the filter 4. Hereinafter, in the longitudinal direction (axial direction) of the tobacco rod 2, the end portion on the side connected to the filter 4 is referred to as a "rear end", and the end portion on the opposite side to the rear end is referred to as a "front end" ( Cutting edge). Further, in the longitudinal direction (axial direction) of the filter 4, the end portion on the side connected to the tobacco rod 2 is referred to as "front end", and the end portion on the opposite side to the front end is referred to as "suction end". Further, a cross section of the cigarette 1 (tobacco rod 2, filter 4) along the longitudinal direction (axial direction) is defined as a "longitudinal section", and a section perpendicular to the longitudinal section is defined as a "cross section". Further, the symbol CL shown in Fig. 1 shows the central axis of the cigarette 1 (tobacco rod 2, filter 4).

Inside the filter 4, it has been arranged in order from the front end side. The filter section S1, the front section S2, and the suction end section S3. In the filtration section S1, a filter material 41 in which a fiber bundle of cellulose acetate formed into a cylindrical shape is wound by a winding paper is provided. However, the filter material 41 of the present embodiment is not limited to the fiber bundle of cellulose acetate, and various materials can be used.

Center hole filters 42 and 43 are respectively disposed in the front stage section S2 and the suction port end section S3, and the center hole filter is formed into a cylindrical shape, and a through-path is formed along the axial direction by winding the paper. Fiber bundle of cellulose acetate. Hereinafter, the through-passage formed in the center hole filter 42 in the front stage section S2 will be referred to as "first center hole 42a". Further, the through passage formed in the center hole filter 43 of the suction port end section S3 is referred to as a "second center hole 43a".

The first central hole 42a passes through the center of the central hole filter 42 and penetrates in the axial direction. On the other hand, the second center hole 43a passes through the center of the center hole filter 43, and penetrates in the axial direction. The first central hole 42a and the second central hole 43a are a smoke flow path (passage) for circulating (passing) the mainstream smoke. In the present embodiment, the first center hole 42a and the second center hole 43a are disposed coaxially, and the cross-sectional area of the second center hole 43a is larger than the cross-sectional area of the first center hole 42a. In other words, the cross-sectional area of the through passage in the suction port end section S3 is set to be larger than the cross-sectional area of the through passage in the front stage section S2. Further, the length of the suction end section S3 (the center hole filter 43) in the filter 4 is shorter than the length of the front section S2 (the center hole filter 42). Further, in the present embodiment, the cross-sectional shape of the first center hole 42a and the second center hole 43a is a circular shape, but the shape is not limited thereto.

In the outer layer of paper 3 used to package the filter 4, a The air for ventilation (outside air) is introduced into the filter 4 and dilutes the vent hole 31 of the mainstream smoke. The vent hole 31 is disposed at a position corresponding to the filter section S1 in the filter 4 as shown in Fig. 1 . At the time of smoking, the outside air flows into the filter 4 through the vent hole 31, and the mainstream smoke flowing into the filter 4 from the tobacco rod 2 side is mixed with the air introduced from the vent hole 31, and the mainstream smoke is Dilute.

Next, an example of a method of manufacturing the central hole filters 42 and 43 will be described. The central aperture filters 42, 43 can be fabricated by a variety of conventional methods. Fig. 3 is a view showing the manufacturing apparatus 100 of the central hole filter. The manufacturing apparatus 100 includes a storage container 110 that stores filter fibers (for example, cellulose acetate) 150, a moldable addition unit 120, a molding device 130, a packaging device 140, and the like. The filter fibers 150 stored in the storage container 110 are pulled out along a predetermined pull-out path. Further, in the drawing process, since the filter fiber 150 is subjected to the fiber opening treatment, it is expanded into a sheet shape. Then, the sheet-shaped filter fiber 150 is supplied to the forming device 130 of the subsequent stage by the addition of the plastic enamel such as triacetin by the plastic enamel adding unit 120.

The molding apparatus 130 is a molding apparatus for molding the sheet-shaped filter fiber 150 into a hollow rod-shaped filter continuous body, and is provided with a filter that condenses the sheet-like filter fibers 150 while being formed into a hollow rod shape. The continuum serves as a mandrel (not shown) of the tubular forming path. The sheet-shaped filter fibers 150 supplied to the molding apparatus 130 are drawn into a rod shape around the mandrel, sequentially pulled out, and pulled out from the mandrel, thereby forming a center hole. The continuous system supply of the filter thus formed with a central hole The packaging device 140 to the rear stage. The filter continuous system supplied to the packaging device 140 is wound into a filter rod by winding the paper, and the filter rod is cut into a predetermined length, whereby the central hole filters 42, 43 can be manufactured.

Next, the action and effect of the cigarette 1 of the present embodiment will be described. When the cigarette 1 is smoked, when the mainstream smoke generated by the tobacco rod 2 flows into the filter 4, the mainstream smoke filters the components such as tar and nicotine while passing through the filter material 41 in the filtration section S1. . Further, since the CO contained in the mainstream smoke is a gas phase component, it is not filtered by the filter material 41. Since the vent hole 31 penetrating the outer layer paper is disposed in the filter section S1 of the filter 4, the air introduced through the vent hole 31 is mixed with the mainstream smoke passing through the filter section S1. Thereby, the components in the mainstream smoke are diluted, and the tar, nicotine, CO, etc. contained in the mainstream smoke are reduced.

However, the filter 4 of the present embodiment is designed to have a low filtration and high dilution so that the dilution of the air introduced from the vent hole 31 and the filtration of the filter material 41 become low filtration and high dilution. More specifically, in the partial section of the filter 4, the front section S2 and the suction end section S3 of the section which does not have the function of filtering the mainstream smoke are arranged, thereby achieving low filtration and high dilution.

Here, in the front stage section S2 and the suction port end section S3, central hole filters 42, 43 each having a hollow first central hole 42a and a second central hole 43a are provided. The area other than the hollow first central hole 42a in the cross section of the central hole filter 42 is occupied by the compression-molded fiber bundle. Therefore, in the cross section of the central hole filter 42, the ventilation resistance of the region occupied by the fiber bundle is comparable to that of the first central hole. The ventilation resistance of 42a is very large. Similarly, a region other than the hollow second central hole 43a in the cross section in the central hole filter 43 is occupied by the compression-molded fiber bundle. Therefore, in the cross section of the central hole filter 43, the ventilation resistance of the region occupied by the fiber bundle is much larger than the ventilation resistance of the first central hole 43a. Therefore, the mainstream smoke passing through the filtration section S1 sequentially flows through the first central hole 42a and the second central hole 43a having a small ventilation resistance, and is finally sucked into the oral cavity from the suction end. Thus, the filter 4 of the present embodiment has a filtering function of filtering the components in the smoke of the mainstream smoke only in the filtering section S1, and the subsequent front section S2 and the suction end section S3 do not have the filtering function of the smoke component. . Thereby, the balance between dilution and filtration of mainstream smoke is low filtration and high dilution, and the ratio of CO to tar can be reduced. As a result, the smoking taste of the cigarette 1 is increased, and the fragrance can be enhanced.

Further, the cigarette 1 of the present embodiment is such that the cross-sectional area of the second central hole 43a in the suction port end section S3 is larger than that of the front section from the viewpoint of suppressing the partial attachment of the tar to the suction port end surface of the filter 4 during smoking. The size relationship of the cross-sectional areas of the two through-passages is defined in such a manner that the cross-sectional area of the first center hole 42a in the segment S2 is large. Hereinafter, the filter 4 of the present embodiment will be described with reference to comparative examples shown in Figs. 4 and 5.

Fig. 4 is a longitudinal sectional view of a filter 40 of a comparative example. The filter 40 is provided with a filter material 410 and a central hole filter 430 from the front end side. The filter material 410 and the central pore filter 430 of the filter 40 are substantially equal to the filter material 41 and the central pore filter 43 of the filter 4 of the present embodiment. That is, the filter 40 of the comparative example is substantially identical to the first image. The filter 4 shown is equivalent to the configuration other than the front stage section S2 (the center hole filter 42).

When the cigarette having the filter 40 of the comparative example is smoked, the mainstream smoke flowing from the tobacco rod side to the filter 40 sequentially flows through the central hole 430a of the filter material 410 and the central hole filter 430, and is attracted to the cigarette. In the mouth. Fig. 5 is a view conceptually showing the local tar contamination of the suction port end face of the filter 40 of the comparative example. In the smoking of the cigarette of the comparative example, the tar is likely to locally adhere to the periphery (edge portion) of the center hole 430a of the end face of the mouthpiece, and the tar contamination of the end face of the mouthpiece is likely to become conspicuous.

On the other hand, the filter 4 of the present embodiment sets the cross-sectional area of the second center hole 43a of the suction port end section S3 to be the first one of the front section S2 which is connected upstream of the suction port end section S3. The cross-sectional area of the center hole 42a is larger, so that the local tar contamination of the periphery (edge portion) of the second center hole 43a of the suction port end face is less likely to become conspicuous.

That is, as shown in Fig. 1, the filter 4 of the present embodiment is at a position deeper from the end face of the suction port and is a boundary position between the front section S2 and the suction end section S3, and the cross-sectional area of the flow path of the mainstream smoke is increased. (first central hole 42a → second central hole 43a). Further, when the boundary position between the front stage section S2 and the mouth end section S3 flows from the first center hole 42a to the second center hole 43a, the mainstream smoke expands in the cross-sectional direction and flows into the second center hole 43a. . Therefore, in the rear end face of the central hole filter 42, a local tar adhesion may occur around the first central hole 42a (edge portion). However, as shown in Fig. 1, the end face of the central hole filter 42 is disposed at a position deeper from the end face of the suction port to the length of the suction port end section S3. Therefore, with There is an advantage that even if local tar adhesion occurs around the first central hole 42a of the end face after the central hole filter 42, the tar contamination is difficult to be visually recognized by the smoker.

Next, the flow rate (flow rate) of the mainstream smoke flowing on the center side and the outer circumference side of the second center hole 43a will be described. The second central hole 43a has a larger cross-sectional area than the first central hole 42a. Therefore, the center side of the second central hole 43a overlaps the first central hole 42a in the axial direction, and the outer peripheral side does not overlap with the first central hole 42a. Overlap in the axial direction. As a result, the flow velocity (flow rate) of the mainstream smoke in the region on the outer peripheral side is relatively slower (less) than the center side of the second center hole 43a. Thus, by reducing the flow rate (flow rate) of the mainstream smoke flowing on the outer peripheral side of the second central hole 43a, the frequency of contact between the mainstream smoke attracted to the oral cavity from the rear end of the second central hole 43a and the end face of the mouth can be reduced. . Therefore, localized tar adhesion to the periphery (edge portion) of the second center hole 43a in the end face of the suction port can be made less likely to occur. As a result, tar contamination of the suction port end face of the filter 4 can be suppressed, and it is not easy to stand out.

Further, according to the present embodiment, it is possible to achieve low filtration and high dilution of the filter 4 without providing a section such as a chamber (cavity) in which the entire cross section of the filter 4 is hollow (cavity). According to the above, it is possible to suppress the occurrence of insufficient hardness throughout the entire section in the longitudinal direction of the filter 4. Therefore, it is possible to suppress the occurrence of inadvertent deformation of the filter 4 before or during smoking. As described above, according to the cigarette 1 of the present embodiment, the tar contamination of the suction port end surface of the filter 4 is not easily conspicuous, and the hardness of the filter 4 can be appropriately suppressed.

Further, the filter 4 of the present embodiment is set such that the length of the suction port end section S3 is shorter than the length of the front stage section S2. Here, since the thickness (wall thickness) of the central hole filter 43 is thinner than the thickness (wall thickness) of the central hole filter 42, the length of the central hole filter 43 is made shorter than the length of the front stage section S2, that is, It is possible to more reliably suppress the lack of hardness of the filter 4.

Further, in the present embodiment, the first center hole 42a and the second center hole 43a of the filter 4 are disposed coaxially. According to the above configuration, the frequency of the main smoke flowing out from the second center hole 43a in the end surface of the suction port contacting the end face of the suction port can be more uniformly reduced over the entire circumference of the second center hole 43a. As a result, the tar contamination of the suction port end face of the filter 4 can be made more conspicuous.

Further, in the present embodiment, since the filter member 41 is provided in the filter portion S1 at the end portion of the filter 4, the filter member 41 can be used as the tobacco rod 21 for suppressing entry (overflow) of the tobacco rod 2. The tobacco spill suppressing means in the filter 4 functions. That is, the filter material 41 of the filtration section S1 also serves as a tobacco spill suppressing means. The tobacco spill suppressing means is not limited to the filter material 41 as long as it has a function of suppressing the entry of the shredded tobacco 21 into the filter 4. For example, various materials can be used as a tobacco spill suppressing means such as a mesh material made of metal or resin. However, according to the present embodiment, by using the tobacco spill suppressing means as the filter material 4, the material cost of the filter 4 can be reduced, and the manufacturing process can be suppressed from being complicated.

Further, in the present embodiment, the vent hole 31 of the filter 4 is disposed at a position corresponding to the filter segment S1. By adopting the above configuration, it is possible to smoothly ventilate the air from the vent hole 31. The advantage of being introduced into the filter 4. Further, the vent hole 31 is disposed in the filter section S1. Further, as shown in the present embodiment, the vent hole 31 is disposed on the upstream side of the suction port end section S3, and the flow of air for ventilation (dilution) introduced into the filter 4 from the vent hole 31 is utilized. The mainstream smoke flowing through the first central hole 42a of the front section S2 is easily passed through the center side of the first central hole 42a. That is, the flow of the air flowing in from the vent hole 31 can be made close to the outer peripheral side of the first center hole 42a, and the flow of the mainstream smoke can be brought close to the center side of the first center hole 42a, and the flow can be made to flow toward the downstream side. . The flow of the mainstream smoke and the dilution air is maintained while passing through the second central hole 43a of the suction port end section S3, so that the mainstream smoke attracted to the oral cavity from the rear end of the second central hole 43a is in contact with the end face of the suction port. The effect of frequency reduction will be further improved. Therefore, the tar contamination of the suction port end face of the filter 4 can be made more difficult to stand out. The above-mentioned "moving the mainstream smoke close to the center side of the first center hole 42a" can be obtained by arranging the vent hole 31 at the upstream side of the filter end portion S3 of the filter 4.

Therefore, the vent hole 31 may be appropriately disposed at a position corresponding to the front stage section S2 as in the configuration example shown in Fig. 6, instead of arranging the vent hole 31 at a position corresponding to the front stage section S1. Fig. 6 is a view showing another aspect of the position at which the vent hole 31 is disposed. In the example shown in Fig. 6, the vent hole 31 is disposed at a position corresponding to the segment S2 before the filter 4. As shown in the figure, the vent hole 31 penetrates not only the outer paper 3 but also the side wall of the second central hole 43a surrounding the central hole filter 42. Further, similarly to the case where the vent hole 31 is disposed in the filter section S1, the former can be utilized. The vent hole 31 of the segment section S2 is introduced into the flow of the dilution air in the second center hole 43a of the center hole filter 42, so that the mainstream smoke flows in a state close to the center side of the center hole 42a, and the filter can be made The tar contamination of the end face of the suction port in 4 is not easy to stand out. Further, in the configuration example shown in Fig. 6, the vent hole 31 is opened to both the side wall of the center hole filter 42 and the outer layer paper 3, but the vent hole 31 may be opened only toward the outer layer paper 3. That is, in this case, the air that has passed through the central hole filter 42 can also be introduced into the second central hole 43a.

Next, the diameter and length of the first central hole 42a and the second central hole 43a of the filter 4 will be exemplarily described. In the present embodiment, a series of a range in which the diameter of the first center hole 42a in the front stage section S2 (the center hole filter 42) is set to be 26% or more and 39% or less of the diameter of the filter 4 is taken as an example. . For example, when the diameter of the filter 4 is a general size of 7.7 mm, the diameter of the first central hole 42a can be exemplified as 2 mm or more and 3 mm or less. Further, when the diameter of the filter 4 is an elongated size of 5.3 mm, the diameter of the first central hole 42a can be exemplified as 1.3 mm or more and 2 mm or less.

On the other hand, the diameter of the second central hole 43a of the suction port end section S3 (the center hole filter 43) is set to be larger than 39% of the diameter of the filter 4 and in the range of 78% or less. As an example. For example, when the diameter of the filter 4 is 7.7 mm, the diameter of the second center hole 43a is set to be larger than 3 mm and 6 mm or less. Further, for example, when the diameter of the filter 4 is 5.3 mm, the diameter of the second central hole 43a is set to be larger than 2 mm and is less than 4.1 mm. kind.

Further, the length of the front section S2 in which the central hole filter 42 is disposed is 7 mm or more, and the length of the suction end section S3 of the central orifice filter 43 is 5 mm or more and 10 mm or less. Further, a ratio (diameter/length) of the diameter to the length of the second central hole 43a of the suction port end section S3 is 0.3 or more and 1.2 or less. From the viewpoint of being difficult to visually recognize the local tar contamination of the end surface after the front section S2 (the center hole filter 42), it is preferable to set the ratio of the diameter to the length of the second center hole 43a to 1.2 or less.

Further, the cross-sectional shape of the first central hole 42a of the front section S2 and the second central hole 43a of the suction end section S3 is not limited to a circular shape, and various shapes may be employed. Here, when the cross-sectional shape of the first center hole 42a is not a circular shape, the first central hole 42a is formed such that the diameter of the first central hole 42a is rounded to 2 mm or more and 3 mm or less. In addition, when the cross-sectional shape of the second center hole 43a is not circular, the second central hole 43a is formed such that the diameter of the inscribed circle of the second central hole 43a is larger than 3 mm and is less than 6 mm. Aspect.

<Modification>

The filter 4 of the present embodiment can adopt various modifications. Hereinafter, a modification of the filter 4 of the present embodiment will be described.

Fig. 7 is a longitudinal sectional view showing a cigarette 1A of Modification 1. The filter 4A provided in the cigarette 1A is provided with a charcoal filtration section S0 containing a charcoal (activated carbon)-added filter material 44 in the preceding stage of the filtration section S1. Other than this point, it is common to the filter 4 shown in Fig. 1. From the front end side of the filter 4A, the charcoal filter section S0, the filter section S1, the front section S2, and the suction end section S3 are sequentially disposed. The charcoal-added filter material 44 disposed in the charcoal filter section S0 is a charcoal filter in which a cellulose acetate fiber bundle to which activated carbon (for example, carbon from a coconut shell of 20 to 80 Mesh) is added by winding paper. In addition, charcoal (activated carbon) functions as a sputum absorbing material that absorbs smoke in mainstream smoke.

In the present modification, a filter material 41 made of cellulose acetate fibers is connected to the charcoal-added filter material 44. According to the filter material 41, the filter material 41 disposed in the subsequent stage of the charcoal-added filter material 44 can be immersed in the first stage S2 (central-hole filter 42) as the activated carbon added to the charcoal-added filter material 44. The central hole 42a functions as an activated carbon overflow suppressing means. In addition, a metal or resin mesh material that functions as an activated carbon overflow suppressing means may be disposed instead of the filter material 41 disposed at the rear end of the charcoal filter section S0.

Further, in the filter 4 shown in Fig. 1, although the front stage section S2 and the mouth end section S3 are disposed as an example of a section having no filtering function, it may be appropriately applied to the filter section S1. A section having no filtering function, a section having a filtering function, and the like are disposed between the preceding section S2. That is, the filter 4 of the present embodiment sets the cross-sectional area of the second center hole 43a of the through-passage path belonging to the suction port end section S3 to be larger than the front section S2 which is located immediately upstream of the suction port end section S3. The cross-sectional area of the first central hole 42a of the road may be large, and the configuration of the filter 4 on the upstream side of the front section S2 may adopt various modifications.

Fig. 8 is a longitudinal sectional view showing a cigarette 1B of Modification 2. In the filter 4B provided in the cigarette 1B of the second modification, the central hole sections S4 and S5 are additionally disposed between the filter section S1 and the front section S2 of the filter 4 shown in Fig. 1 . In the central hole section S4, a central hole filter 45 having a third central hole 45a is disposed, and in the central hole section S5, a central hole filter 46 having a fourth central hole 46a is disposed. In the filter 4B shown in Fig. 8, a third center hole 45a, a fourth center hole 46a, a first center hole 42a, and a second center hole 43a are coaxially arranged. Further, the flow path sectional area of the mainstream smoke of each of the center holes is increased in the order of the third central hole 45a, the fourth central hole 46a, the first central hole 42a, and the second central hole 43a. Even in this modification, the same effect as the filter 4 shown in Fig. 1 can be exhibited, and the tar contamination of the suction port end surface of the filter can be made less conspicuous, and the hardness of the filter can be suppressed from being insufficient.

Fig. 9 is a longitudinal sectional view showing a cigarette 1C of Modification 3. The filter 4C included in the cigarette 1C of the third modification replaces the positions of the central hole sections S4 and S5 of the filter 4B shown in Fig. 8. That is, in the filter 4C, the filter section S1, the center hole section S5, the center hole section S4, the front section S2, and the suction end section S3 are sequentially disposed from the front end side. In the filter 4C of the third modification, the mainstream smoke passing through the filter section S1 flows into the fourth central hole 46a, and is sequentially smoked after passing through the third central hole 45a, the first central hole 42a, and the second central hole 43a. The person is pumping. In the present modification, the cross-sectional area of the second center hole 43a of the suction port end section S3 is also set to be larger than the first center hole 42a of the front section S2 which is connected upstream of the suction port end section S3. The cross-sectional area is large, so the filter shown in Figure 1 4 Similarly, the tar contamination of the suction port end face of the filter is not easily conspicuous, and the hardness of the filter can be suppressed to be insufficient.

Although the preferred embodiment of the present invention has been described above, various types of changes, improvements, combinations, and the like can be made to the cigarette with the filter in the embodiment.

1‧‧ ‧ Cigarettes

2‧‧‧Tobacco stick

3‧‧‧ outer paper

4‧‧‧Filter

21‧‧‧ cut tobacco

22‧‧‧Roll paper

31‧‧‧ vents

41‧‧‧Filter material

42, 43‧‧‧ central hole filter

42a‧‧‧First central hole

43a‧‧‧Second central hole

S1‧‧‧Filter section

S2‧‧‧Segment

S3‧‧‧ suction end section

Claims (6)

A cigarette with a filter comprising: a tobacco rod comprising shredded tobacco; a filter connected to an end portion of the tobacco rod through an outer paper; the filter having a suction end section and being disposed at the suction end a suction end section, and is provided with a fiber bundle, the fiber bundle is formed with a through-path for flowing mainstream smoke along the axial direction; and the front section is a front section connected to the front end of the suction end section And a fiber bundle is provided, wherein the fiber bundle is formed with a through passage for the mainstream smoke to flow along the axial direction; and a cross-sectional area of the through passage in the suction end portion is more than a cross-sectional area of the through passage of the front section Big. The cigarette with a filter according to claim 1, wherein the length of the mouth end section is shorter than the length of the front section. The cigarette with a filter according to claim 1 or 2, wherein each of the suction end section and the front section is coaxially disposed. The filter-attached cigarette according to any one of the preceding claims, wherein the front end of the filter is provided with a tobacco spill suppressing means for suppressing entry of the shredded tobacco into the filter. . The cigarette with a filter according to the fourth aspect of the invention, wherein the filter is provided at the front end of the filter for filtering the mainstream In the filter material of the fiber bundle of the smoke, the filter material may also have the above-described tobacco spill suppressing means. The filter-attached cigarette according to any one of claims 1 to 5, wherein the outer layer paper is formed with a vent hole for introducing outside air into the filter and diluting the mainstream smoke. The vent hole is disposed at a position on the upstream side of the suction port end section in the filter.