EP3821733B1

Movatterモバイル変換

Info

Publication number: EP3821733B1
Application number: EP18926212.4A
Authority: EP
Inventors: Tomoharu Miyashita
Original assignee: Daicel Corp
Current assignee: Daicel Corp
Priority date: 2018-07-13
Filing date: 2018-07-13
Publication date: 2023-11-22
Anticipated expiration: 2038-07-13
Also published as: EP3821733A4; PL3821733T3; EP3821733C0; EP3821733A1; WO2020012633A1; KR20210029155A

Description

Technical Field

The present invention relates to a band for a heated tobacco product tip, a heated tobacco product tip, and a method of producing a band for a heated tobacco product tip.

Background Art

US 4 619 279 A discloses a cellulose acetate tow band formed by bundling a plurality of filaments, the tow band integrating 3,000 - 100,000 filaments having a filament denier of 0.8-16, the filaments having a hollow cross-sectional shape including a hollow core part and an outer peripheral part having openings therein which communicate from the exterior. In the present specification, terms defined as described below are used.
TD: An abbreviation for total denier, which refers to the denier (the number of grams per 9000 m) of an assembly of tows (bands).
FD: An abbreviation for a single fiber denier (filament denier), which refers to the denier (the number of grams per 9000 m) of a single fiber (one piece of filament).
Also referred to as the single fiber denier.
Filament: A continuous long fiber. In particular, the term filament refers to a single fiber extruded from a spinneret hole of a spinneret.
Spinneret hole (orifice): A hole formed in a spinneret of a cabinet, and from which a filament is extruded (spun).
Band: A product formed by layering and crimping tows, which are an assembly of filaments (single fibers) extruded from each of a plurality of cabinets, with the TD set to a predetermined value. The tows that are layered with the TD set to a predetermined numeric value are crimped. The crimped tows (assembly of filaments) are called a band. That is, the band has a TD and a crimp-index. The band is packed in a bale form.
Tow: An assembly of a plurality of filaments extruded from spinneret holes. An end and a yarn are each an aspect of the tow.
End: An assembly of filaments having a predetermined total denier formed by layering a plurality of filaments extruded from spinneret holes of a plurality of cabinets.
Yarn: A bundle of filaments extruded from one cabinet. Thus, the yarn is an assembly of filaments before layering.
Feret area: An index that can be used to evaluate the shape-irregularity of a cross section of a filament. The Feret area is obtained as follows: at any position of the filament, the filament is cut in a direction perpendicular to the long-axis direction of the filament to obtain a cross section of the filament. A parallelogram circumscribing this cross section is then imagined. In this imaginary parallelogram, one of two pairs of opposite sides is formed by two parallel lines that circumscribe the cross section of the filament and have an inter-line distance that is a maximum value (a so-called "maximum Feret diameter"). In this imaginary parallelogram, the other pair of the two pairs of opposite sides is two parallel lines that circumscribe the cross-section of the filament and have an inter-line distance that is a minimum value (what is called a "minimum Feret diameter"). The Feret area is an area ratio determined by dividing the cross-sectional area of the filament by the area of the imaginary parallelogram, or in other words, is the occupancy ratio of the filament cross section in the imaginary parallelogram.
Tip: A filter through which tobacco components are passed when a user smokes a cigarette or uses a heated tobacco product. The tip is configured, for example, by forming a predetermined air-permeable material into a rod shape, and winding a rolled paper around the outer circumference thereof.
Filaments made from cellulose acetate, and particularly cellulose diacetate, are useful as a material for tips of cigarettes, including heated tobacco products. In such an application, cellulose acetate bands configured from crimped filaments of long-fiber cellulose acetate are used.
The band used in a cigarette tip is required to have an appropriate amount of pressure drop (PD). For this reason,Patent Document 1 for example discloses, as a band used in a cigarette tip, a band in which the pressure drop is adjusted by setting the filament denier to a value not less than 5.0 and setting the Feret area of the filament to a value not less than 0.5.
In recent years, heated tobacco products have become popular. As disclosed in, for example,Patent Document 2, an aerosol-generating article includes a substrate containing a volatile component that is a tobacco component, a heating element that is configured to heat the substrate, a cooling element that is configured to cool and condensate volatile components from the heated substrate to form an aerosol, and a tip for filtering the aerosol that has passed through the cooling unit.
The tip is held in the mouth of the smoker during use of the heated tobacco product. The tip is produced, for example, using a cellulose acetate band (hereinafter, also referred to simply as a band). In this case, the filaments of the band are opened, a plasticizer is applied thereto, and the material is molded into a rod shape. Then, a rolled paper is wound around the outer circumference of the molded article of the band, and the molded article and rolled paper are cut to a predetermined size to thereby produce the tip.

Citation List

Patent Document

Patent Document 1:WO 2015/136573
Patent Document 2:JP 2015-503335 A

Summary of Invention

Technical Problem

In heated tobacco products, the tobacco components are contained in the aerosol, and therefore the filtration degree of the aerosol at the tip is preferably low so that a smoker can easily inhale and savor the aerosol that has passed through the tip. Also, in heated tobacco products, the pressure drop of the tip is preferably low to allow the smoker to easily inhale the aerosol.
With a heated tobacco product, it is also desirable to obtain an inhalation sensation that is close to that of a normal cigarette. Thus, the tip of the heated tobacco product preferably has an appropriate level of hardness like the tip of an ordinary cigarette.
Here, when the number of filaments of the band included in the tip is reduced in order to suppress a pressure drop in the tip and the filtration degree of the aerosol, the hardness of the tip is reduced. This makes it difficult for a user to experience an inhalation sensation like that of a normal cigarette, and may cause the aerosol to pass through the tip while the temperature of the aerosol is not sufficiently cooled.
Therefore, an object of the present invention is to enable the suppression of the pressure drop and filtration degree of the aerosol while also suppressing a reduction in hardness of a heated tobacco product tip.

Solution to Problem

In a heated tobacco product tip, the aerosol collides with the filaments of the band and is collected. Here, from research by the present inventors, it was found that the aerosol collecting capacity of a filament is approximately equivalent to the aerosol collecting capacity of an imaginary filament having the imaginary parallelogram described above as a cross-sectional shape. As the shape-irregularity of the cross section of the filament increases, the Feret area decreases, and the aerosol collection performance of the filament increases. Also, as the shape-irregularity of the cross section of the filament decreases, the Feret area increases, and the aerosol collection performance of the filament decreases. The following aspects of the present invention were accomplished on the basis of such perspectives.
The above and other objects of the invention are solved by the band for a heated tobacco product tip according toclaim 1, the heated tobacco product tip according toclaim 4 and the method for producing a band for a heated tobacco product tip according toclaim 6. Preferred embodiments are claimed in the dependent claims. A band for a heated tobacco product tip according toclaim 1 is a cellulose acetate band formed by layering and crimping a plurality of filaments in a bundle shape with each filament having a hollow cross-sectional shape with a core portion hollowed and a peripheral portion surrounding the core portion.
According to the above configuration, the filament has a hollow cross sectional shape, and therefore the Feret area can be increased compared to filaments having, for example, a Y-shaped cross section. This configuration enables adjustment of the shape-irregularity of the filaments to an appropriate value. Thus, in a heated tobacco product tip using a band containing the filaments thereof, the filtration degree of the aerosol can be appropriately suppressed, and the amount of aerosol that is collected can be reduced. Also, adjustment of the shape-irregularity of the filaments to an appropriate value improves flow of gas in the heated tobacco product tip, and can suppress a pressure drop of the heated tobacco product tip.
Also, the number of filaments of the band included in the heated tobacco product tip need not be reduced in order to suppress the filtration degree of the aerosol, and therefore a decrease in hardness of the heated tobacco product tip due to a reduction in the number of filaments can be suppressed.
Moreover, for a given cross-sectional area of the filament, the diameter of the filament can be larger than that of a filament having a solid core portion, and therefore the bending moment of the filament can be increased. Thereby, the rigidity of the filament can be increased, and a decrease in hardness of the tip can be favorably suppressed.
The filament denier is set to a value in a range of not less than 5.0 and less than 30.0. With this configuration, a gap between fibers can be prevented from becoming excessively large. Thus, for example, the matter of a foreign substance entering into the gap between fibers and passing there through can be prevented. Also, if capsules containing a flavor component are dispersed in the heated tobacco product tip, fragments of the capsules are prevented from flowing through the gap between fibers, and the contents of the capsules are prevented from passing through the tip all at once. Setting the filament denier to such a value also prevents the aerosol from flowing through the gap between fibers and passing through the tip without being sufficiently cooled.
An opening portion that communicates with the core portion from the outside is formed in the peripheral portion. Additionally, a porosity (%) represented by (L1 / L0) × 100 is set to a value in a range of not less than 0 and not greater than 20. Herein, L0 is a circumferential length of the peripheral portion in a cross section of the filament, and L1 is a circumferential length of the opening portion in the cross section of the filament. With this configuration, the surface area, cross-sectional area and cross-sectional shape of the filament can be easily adjusted.
The circumferential length of the opening portion in the cross section of the filament may be set to a value in a range of not greater than 1/3 of the diameter of the filament. With this configuration, the surface area, cross-sectional area, and cross sectional shape of the filament can be easily adjusted, and the rigidity of the filament can be easily ensured.
A total denier is set to a value in a range of not less than 5000 and not greater than 50000. With this configuration, the number of filaments during crimping is set to a relatively large number, and thereby each filament can be stably crimped.
A heated tobacco product tip according toclaim 4 is provided with a molded article formed by molding any of the bands described above into a rod shape, and a rolled paper wound around the circumferential surface of the molded article.
According to the above configuration, with the band described above, a heated tobacco product tip can be favorably realized with a suppressed pressure drop and a suppressed filtration degree of the aerosol while a decrease in hardness is suppressed.
A method for producing a band for a heated tobacco product tip according toclaim 6 includes spinning a plurality of filaments, and layering and crimping in a bundle shape the plurality of filaments that have been spun, and in the spinning, filaments are spun with each of the filaments having a hollow cross-sectional shape with a core portion hollowed and a peripheral portion surrounding the core portion.
According to the above method, each of the filaments that are spun in the spinning has a hollow cross-sectional shape, and therefore the Feret area can be increased compared to a filament having a Y cross-section, for example. With this configuration, the shape-irregularity of the filaments can be adjusted to an appropriate value. Thus, in a heated tobacco product tip using a band containing the filaments thereof, the filtration degree of the aerosol can be appropriately suppressed, and the amount of aerosol that is collected can be reduced. Also, adjusting the shape irregularity of the filaments to an appropriate value improves flow of gas in the heated tobacco product tip, thereby suppressing a pressure drop of the heated tobacco product tip.
Also, the number of filaments of the band included in the heated tobacco product tip need not be reduced to suppress the filtration degree of the aerosol, and therefore a decrease in hardness of the heated tobacco product tip due to a reduction in the numberof filaments can be suppressed.
Moreover, for a given cross-sectional area of the filament, the diameter of the filament can be larger than that of a filament having a solid core portion, and therefore the bending moment of the filament can be increased. Thereby, the rigidity of the filament can be increased, and a decrease in hardness of the tip can be favorably suppressed.
The filaments that are spun in the spinning are filaments having a filament denier that is set to a value in a range of not less than 5.0 and less than 30.0. With this configuration, the matter of the gap between fibers becoming excessively large in the band after production can be prevented. Thus, for example, the matter of a foreign substance entering into the gap between fibers and passing therethrough can be prevented. Also, if capsules containing a flavor component are dispersed in the heated tobacco product tip, fragments of the capsules are prevented from flowing through the gap between fibers, and the contents of the capsules are prevented from passing through the tip all at once. Setting the filament denier to such a value also prevents the aerosol from flowing through the gap between fibers and passing through the tip without being sufficiently cooled.
The filaments that are spun in the spinning are filaments each having an opening portion that is formed in the peripheral portion and communicates with the core portion from the outside. With this configuration, the surface area, cross sectional area, and cross-sectional shape of the filament can be easily adjusted.
In the spinning, each of the filaments may be spun by extruding, in an atmosphere set at a temperature in a range of not lower than 40°C and not higher than 20 80°C, a spinning dope from an orifice having a circular edge shape.
With this configuration, the surface area, cross-sectional area, and cross sectional shape of the each of the filaments can be easily adjusted, and by adjusting the temperature while using a typical spinning device, the filaments each having a hollow cross-sectional shape with a core portion hollowed and a peripheral portion surrounding the core portion can be favorably spun.
In the spinning, each of the filaments may be spun by extruding the spinning dope from an orifice having an edge shape with a notch in a part of the edge. With this configuration, the surface area, cross-sectional area, and cross-sectional shape of each of the filaments can be easily adjusted by extruding the spinning dope from an orifice having an edge shape with a notch in a part of the edge. In addition, when a typical spinning device replaced with the spinneret having an orifice of the shape described above is used, filaments each having a hollow cross-sectional shape and with a core portion hollowed and a peripheral portion surrounding the core portion can be favorably spun.
In the spinning, each of the filaments having a porosity (%), represented by (L1 / L0) × 100, set to a value in a range of not less than 0 and not greater than 20 is spun. Herein, L0 is a circumferential length of the peripheral portion in a cross section of the filament after production, and L1 is a circumferential length of the opening portion in the cross section of the filament after production. With this configuration, the surface area, cross-sectional area, and cross-sectional shape of the filament can be easily adjusted.
In the spinning, the filaments may be spun with the each of the filaments having, in a cross section after production, a circumferential length of the opening portion set to a value in a range of not greater than 1/3 of the diameter of the filament. With this configuration, the surface area, cross-sectional area, and cross-sectional shape of the filament can be easily adjusted, and the rigidity of the filament can be easily ensured.
In the spinning, the filaments are spun, with a total denier set to a value in a range of not less than 5000 and not greater than 50000. With this configuration, the number of filaments during crimping is set to a relatively large number, and thereby each filament can be stably crimped.

Advantageous Effects of Invention

According to the present invention, the pressure drop and filtration degree of the aerosol can be suppressed while a decrease in the hardness in the heated tobacco product tip being suppressed.

Brief Description of Drawings

FIG. 1 is an overall view of a band production apparatus according to a first embodiment.
FIG. 2 is a cross-sectional view of a cellulose acetate filament ofFIG. 1.
FIG. 3 is an overall view of a tip production apparatus according to the first embodiment.
FIG. 4 is a cross-sectional view of a heated tobacco product according to the first embodiment.
FIG. 5 is a diagram for describing cave-in of a heated tobacco product tip.
FIG. 6 is a front view of an orifice formed in a spinneret according to a second embodiment.
FIG. 7 is a front view of an orifice formed in a spinneret according to a third embodiment.
FIG. 8 is a cross-sectional view of a cellulose acetate filament spun by the orifice ofFIG. 7.
FIG. 9 is a front view of an orifice formed in a spinneret according to a fourth embodiment.
FIG. 10 is a cross-sectional view of a cellulose acetate filament spun by the orifice ofFIG. 9.

Description of Embodiments

Various embodiments of the present invention are described with reference to the drawings.

(First Embodiment)

[Cellulose Acetate Band Production Apparatus]

FIG. 1 is an overall view of a cellulose acetate (hereinafter, also referred to as CA)band production apparatus 1.FIG. 2 is a cross-sectional view of aCA filament 61 ofFIG. 1. As illustrated inFIG. 1, the CAband production apparatus 1 spinsCA filaments 61 by dry spinning. Furthermore, the CAband production apparatus 1 produces, from theCA filaments 61, ayarn 62, anend 63, and aCA band 64.
The CAband production apparatus 1 is provided with amixing device 2, afiltering device 3, aspinning unit 4, alubrication unit 5, agodet roll 6, guide pins 7, 8, a crimpingdevice 9, and adrying device 10.
In the CAband production apparatus 1, aspinning dope 60 is used in which CA flakes such as cellulose diacetate are dissolved in an organic solvent at a predetermined concentration (for example, a weight concentration value in a range of not less than 20 wt.% and not greater than 30 wt.% of the spinning dope 60).
The spinningdope 60 is mixed using themixing device 2, and then filtered by afiltering device 3. The spinningdope 60 that has passed through thefiltering device 3 is extruded from a plurality oforifices 15a of aspinneret 15 provided on acabinet 14 of thespinning unit 4.
Theorifice 15a has a circular edge shape. The diameter of theorifice 15a is set, as appropriate, in accordance with the FD of theCA filament 61 after production. The spinningdope 60 extruded from eachorifice 15a is heated at an atmospheric temperature (temperature inside the cabinet 14) in a range of not lower than 40°C and not higher than 80°C and the organic solvent vaporized, by hot air supplied into thecabinet 14 from a drying unit (not illustrated), whereby thespinning dope 60 is dried. The temperature of the hot air blown into thecabinet 14 is set to a value in a range of not lower than 70°C and not higher than 80°C, for example. With this configuration, asolid CA filament 61 is formed.
Here, the cross-sectional shape of the producedCA filament 61 varies depending on the relationship between an evaporation rate and a diffusion rate, the evaporation rate being defined as the rate at which the organic solvent evaporates from the surface of thespinning dope 60 that has passed through theorifice 15a, and the diffusion rate being defined as the rate at which the organic solvent diffuses to the surface of thespinning dope 60 from the center in the radial direction of thespinning dope 60 that has passed through theorifice 15a.
When an evaporation surface area defined as the surface area of thespinning dope 60 that has passed through theorifice 15a is relatively large, the evaporation rate becomes faster than the diffusion rate. In this case, after the surface of thespinning dope 60 has solidified and a skin layer has been formed, the organic solvent diffuses from the inside to the surface of thespinning dope 60. As a result, the cross-sectional shape of theCA filament 61 after production easily becomes irregular.
In the present embodiment, the cross-sectional shape of thespinning dope 60 immediately after passing through theorifice 15a is circular. When the temperature of the atmosphere inside thecabinet 14 is set to the range described above, the diffusion rate increases at a portion in the circumferential direction in a cross section of thespinning dope 60, and the organic solvent diffuses from the center in the radial direction of thespinning dope 60 toward the surface of thespinning dope 60.
As a result, internal drying of thespinning dope 60 proceeds via the portion in the circumferential direction as the skin layer is formed. As illustrated inFIG. 2, consequently, though shape-irregularity is suppressed as a whole, a portion of the filament corresponding to the portion of thespinning dope 60 in the circumferential direction caves in towards the radial center of thespinning dope 60, making the cross-sectional shape of theCA filament 61 to be C-shape.
Here, as presented in Comparative Example 1 described below, in a case where the orifice has a circular edge shape, the excessively high temperature of the hot air blown into the cabinet 14 (in other words, the maximum temperature of the atmosphere in the cabinet 14) may increase the Feret area, and reduce the shape-irregularity of the CA filaments, for example. As a result, the cross-sectional shape of the CA filament to be spun is different from the cross-sectional shape of theCA filament 61.
Note that the disclosure of thePatent Document 2 can be referenced for details regarding the basic method for spinning theCA filaments 61 having a target shape by adjusting the value of the Feret area of theCA filament 61.
As illustrated inFIG. 1, a plurality of theCA filaments 61 that have passed through onecabinet 14 are gathered by the guide pins 7, 8, thereby forming ayarn 62. After the lubricant is applied by thelubrication unit 5, theyarn 62 is wound by thegodet roll 6. Theyarn 62 is then taken up by a predetermined winding device.
A series of units for producing theyarn 62, namely, thespinning unit 4 that extrudes the spinningdope 60 from thespinneret 15 and spins theCA filaments 61, the drying unit, thelubrication unit 5, and a winding unit having the godet roll, is collectively referred to as a station. Typically, a plurality of stations are arranged in a line.
Theyarn 62 is taken up from the circumferential surface of thegodet roll 6 by the winding device. Theyarn 62 that has passed through each station is conveyed along the arrangement direction of the stations and sequentially accumulated or stacked. With this configuration, a plurality of theyarns 62 are layered to form an end (a tow) 63, which is a flat assembly of theyarns 62. Theend 63 is formed by layering the plurality ofyarns 62, and is set to a predetermined TD. Theend 63 is conveyed and guided to a crimpingdevice 9.
The crimpingdevice 9 has a pair of nip rolls 16, 17 and a stuffing box (crimping box) 18. Theend 63 is passed between the pair of nip rolls 16, 17, and then pushed into thestuffing box 18. The pair of nip rolls 16 pushes theend 63 into thestuffing box 18 with a force larger than the resistance that occurs when theend 63 is pushed into thestuffing box 18, and thereby crimping is imparted to theend 63. TheCA band 64 is thus produced.
TheCA band 64 that has passed through the crimpingdevice 9 is dried with the dryingdevice 10. TheCA band 64 that has passed through the dryingdevice 10 is accumulated and then subjected to compression packing in apackaging container 19 to form a bale.FIG. 1 illustrates a cross-sectional structure of thepackaging container 19.
As illustrated inFIG. 2, theCA filament 61 included in theCA band 64 has a hollow cross-sectional shape with acore portion 61a hollowed and aperipheral portion 61b surround ing thecore portion 61a. As one example, this hollow cross sectional shape is annular. Here, the term annular is not limited to a perfect circle in which the circumference is completely closed, and also includes a circular ring in which a portion of the circumference is open, or a circular ring in which the shape is slightly distorted. As an example, theCA filament 61 of the present embodiment has anopening portion 61c that is formed in theperipheral portion 61b and communicates with thecore portion 61 a from the outside.
In this manner, the method for producing theCA band 64 of the present embodiment includes spinning a plurality ofCA filaments 61, and layering and crimping a plurality of spunCA filaments 61 in a bundle shape.
In the spinning, theCA filament 61 having a hollow cross-sectional shape and with acore portion 61a hollowed and aperipheral portion 61b that surrounds thecore portion 61a is spun. Furthermore, in the spinning, as one example, the spinningdope 60 is extruded from theorifice 15a having a circular edge shape, in an atmosphere set to a temperature in a range of not lower than 40°C and not higher than 80°C, and thereby aCA filament 61 is spun with anopening portion 61c that communicates with thecore portion 61a from the outside and is formed in theperipheral portion 61b.
Also, in the spinning, aCA filament 61 with a porosity (%)defined by (L1 / L0) × 100 is set to a value in a range of not less than 0 and not greater than 20 is spun. Here, L0 is a circumferential length of theperipheral portion 61b in a cross section of theCA filament 61 after production, and L1 is a circumferential length of theopening portion 61c in the cross section of theCA filament 61 after production.
Also as an example, in the spinning, theCA filament 61 is spun to have, in across section of theCA filament 61 after production, a circumferential length of theopening portion 61c set to a value in a range of not greater than 1/3 of the diameter of theCA filament 61. Also, in the spinning, theCA filament 61 is spun to have a total denier set to a value in a range of not less than 5000 and not greater than 50000.
Production of theCA filament 61 by the method described above results in a value of the porosity (%) defined by (L1 / L0) × 100 in a range of not less than 0 and not greater than 20. Additionally, production of theCA filament 61 by the method described above results in the circumferential length of theopening portion 61c in the cross section of theCA filament 61 in a range of not greater than 1/3 of the diameter of theCA filament 61.
The FD of theCA band 64 is set to a value in a range of not less than 5.0 and less than 30.0. Moreover, the TD of theCA band 64 is set to a value in a range of not less than 5000 and not greater than 50000. The Feret area of theCA filament 61 is set to a value less than 0.7.
Here, the circumferential length L1 can be set as appropriate, and is preferably set to a value in a range of not greater than 14 the diameter of the circumferential length L0, and is more preferably set to a value in a range of not greater than 1/5 the diameter of the circumferential length L0. The value of the FD of the CA filament 61can be set as appropriate, but is preferably a value in a range of not less than 7.0 and not greater than 28.0, and more preferably a value in a range of not less than 8.0 and not greater than 20.0.

[Tip Production Apparatus]

FIG. 3 is an overall view of a tip production apparatus 20 according to an embodiment. As illustrated inFIG. 3, the tip production apparatus 20 is provided with alayering ring 21, a firstfilament opening unit 22, aturn baffle 23, a secondfilament opening unit 24, a pair of pre-tension rolls 25, a pair of first filament opening rolls 26, a pair of second filament opening rolls 27, a thirdfilament opening unit 28, aplasticizer application device 29, a pair of conveyingrolls 30, atransport jet 31, atransport stuffer unit 32, and acutting device 33.FIG. 3 illustrates a cross-sectional structure of thepackaging container 19.
In the tip production apparatus 20, after theCA band 64 fed out from thepackaging container 19 has been passed through thelayering ring 21, theCA band 64 is subjected to filament opening in the width direction by pressurized air in the firstfilament opening unit 22. TheCA band 64 is then guided by theturn baffle 23.
Next, after theCA band 64 is subjected to further filament opening in the width direction using pressurized air at the secondfilament opening unit 24, the filaments of theCAband 64 are opened in the conveyance direction thereof by passing theCA band 64 between the pair of pre-tension rolls 25, the pair of first filament opening rolls 26, and the pair of second filament opening rolls 27, in this order.
TheCA band 64 that has passed between the pair of second filament opening rolls 27 is further opened in the width direction by pressurized air at the thirdfilament opening unit 28, and then a plasticizer is applied by theplasticizer application device 29.
TheCA band 64 that has passed through theplasticizer application device 29 is passed between the pair of conveyingrolls 30, after which capsules 74 (seeFIG. 4) are added by a predetermined addition device. TheCA band 64 is then introduced into thetransport jet 31 and conveyed into thetransport stuffer unit 32 by a jet air flow.
Thetransport stuffer unit 32 has afunnel 41, atongue 42, and agarniture 43. TheCA band 64 conveyed into thetransport stuffer unit 32 is spirally wound at thefunnel 41 and molded into a rod shape. As a result, a moldedarticle 65 is formed in which theCAband 64 is molded into a rod shape.
Also, the rolledpaper 40 is guided toward the moldedarticle 65 by thetongue 42. The moldedarticle 65 is conveyed by thegarniture 43, and the rolledpaper 40 is wound around the moldedarticle 65. Then, the rolled paper is fixed on the outer circumference of the moldedarticle 65. The cuttingdevice 33 cuts the moldedarticle 65 at intervals. With this configuration, aplug 66 is produced. Theplug 66 is further cut, and atip 67 is produced.

[Heated Tobacco Product Tip]

FIG. 4 is a cross-sectional view of aheated tobacco product 50 according to an embodiment. As illustrated inFIG. 4, theheated tobacco product 50 has a long shape and is provided with a heatedtobacco product unit 51 and anaerosol generating article 52. The heatedtobacco product unit 51 has anenclosure 53, apower supply 54, adisplay unit 55, acontrol unit 56, aheating unit 57, and anoperation unit 58.
Theenclosure 53 is formed in a long shape. Thepower supply 54, thecontrol unit 56, and theheating unit 57 are housed in theenclosure 53. Thedisplay unit 55 and theoperation unit 58 are disposed on an outer surface of the enclosure 53 (here, a side surface of theenclosure 53, which is on the far side of theenclosure 53 in the view). In the present embodiment, the shape of theenclosure 53 is a straight tubular shape in which one end in the longitudinal direction of the heatedtobacco product unit 51 is closed.
Thecontrol unit 56 is connected to thepower supply 54, thedisplay unit 55, and theheating unit 57 by awire 68. Thecontrol unit 56 is, as one example, a single-chip microcomputer, and accepts operation input by the smoker from theoperation unit 58. With this configuration, thecontrol unit 56 is configured to control the power supply circuit of the heatedtobacco product unit 51 to supply power of thepower supply 54 to theheating unit 57 at a predetermined timing, or to stop the supply of power to theheating unit 57. Thecontrol unit 56 is configured to control thedisplay unit 55 to display predetermined information for the smoker.
As one example, thepower supply 54 is a secondary battery, and is a lithium ion battery in the present embodiment. Thedisplay unit 55 is an LCD, but may also be configured to not display characters. If thedisplay unit 55 does not display characters, thedisplay unit 55 may be a lamp such as an LED lamp, for example.
Theheating unit 57 is configured to heat thesubstrate 70 of theaerosol generating article 52 using power supplied from thepower supply 54. Theheating unit 57 is disposed in the heatedtobacco product unit 51 such that it is in contact with thesubstrate 70. Theheating unit 57 of the present embodiment has ablade 70a, which is inserted into thesubstrate 70 and is configured to heat thesubstrate 70 internally by Joule heat. Apath 59 is provided between theenclosure 53 and theheating unit 57. Thepath 59 is configured to flow outside air toward thesubstrate 70 from a gap between aninsertion port 51a and theaerosol generating article 52 when theheated tobacco product 50 is in use.
Theaerosol generating article 52 is inserted into theinsertion port 51a formed in the other end of the heatedtobacco product unit 51 in the longitudinal direction, during use of theheated tobacco product 50. Theaerosol generating article 52 has a rod-like shape, and has thesubstrate 70, aseparator pipe 71, anaerosol generating unit 72, atip 67, and a rolledpaper 73. In theaerosol generating article 52, thesubstrate 70, theseparator pipe 71, theaerosol generating unit 72, and thetip 67 are arranged in this order from one end to the other end of theaerosol generating article 52 in the longitudinal direction. The rolledpaper 73 is integrally wrapped around the outer circumference of theseelements 66, 70, 71, and 72.
Thesubstrate 70 is disposed at one end of theaerosol generating article 52 in the longitudinal direction. Thesubstrate 70 contains a volatile component that is a tobacco component, and is inserted into the interior of the heatedtobacco product unit 51 from theinsertion port 51a of the heatedtobacco product unit 51. Thesubstrate 70 is heated by theheating unit 57 when theheated tobacco product 50 is in use, and thereby a volatile component is generated.
Thesubstrate 70 contains a flavoring material, e.g. nicotine, that generates a volatile component. Specifically, thesubstrate 70 preferably includes at least any of tobacco leaves, tobacco ribs, expanded tobacco, homogenized tobacco, and herbal leaves. These materials may be included, for example, in a solid form, such as in any shape including a narrow fragment, a powder, a thread, or a band, or may be included in the form of a liquid, or may be included in both solid and liquid forms. When the material is included in the form of a liquid, the liquid of the material may be encapsulated in a capsule. Such capsules are heated and melted during use of theheated tobacco product 50.
Thesubstrate 70 may also include a flavoring material other than nicotine. The flavoring material may be held on a thermally stable carrier. The flavoring material may also be held on the carrier in the form of a sheet, foam, gel, or slurry. The flavoring material may also be uniformly contained in theentire substrate 70 or may be contained unevenly in thesubstrate 70.
Theseparator pipe 71 extends in the longitudinal direction of theaerosol generating article 52 and is disposed between thesubstrate 70 and theaerosol generating unit 72, and thereby functions as a separator separating thesubstrate 70 and theaerosol generating unit 72. With this configuration, when theaerosol generating article 52 is inserted into the interior of the heatedtobacco product unit 51 from theinsertion port 51a, theseparator pipe 71 prevents theaerosol generating article 52 from being compressed in the longitudinal direction, and thesubstrate 70 from being crushed to the extent of contact with theaerosol generating unit 72.
Theseparator pipe 71 of the present embodiment is formed into a hollow rod shape. In the hollow portion of theseparator pipe 71, the volatile components generated from thesubstrate 70 when theheated tobacco product 50 is in use flow towards thetip 67. As an example, theseparator pipe 71 is constituted from cellulose diacetate, but is not limited thereto, and may be constituted from other materials such as polypropylene.
Theaerosol generating unit 72 extends in the longitudinal direction of theaerosol generating article 52 and is configured to generate the aerosol by cooling and condensing volatile components, which are from thesubstrate 70 and have passed through theseparator pipe 71.
Theaerosol generating unit 72 may include, for example, a band-shaped sheet body wound in the circumferential direction of theaerosol generating article 52, or a band-shaped sheet body that is finely folded up with each fold extending in the longitudinal direction of theaerosol generating article 52. In theaerosol generating unit 72, a flow path for aerosol is formed by a gap between the wound or finely folded-up sheet bodies.
The sheet body of theaerosol generating unit 72 may include, for example, any material such as polyethylene, polypropylene, polyvinyl chloride, PETG (high strength polyethylene terephthalate (polyethylene terephthalate copolymer)), polylactic acid, cellulose acetate, starch-based polyester, porous paper, aluminum foil, and the like. Considering that theaerosol generating article 52 is a disposable article, the sheet body is preferably constituted from a material such as a biodegradable polylactic acid or porous paper.
Thetip 67 of the present embodiment is produced by the tip production apparatus 20 using theCA band 64 produced by the CAband production apparatus 1. Thetip 67 is disposed at the other end of theaerosol generating article 52 in the longitudinal direction.
Thetip 67 includes a moldedarticle 65 and a rolledpaper 40 wound around the circumferential surface of the moldedarticle 65. Thetip 67 is held in the mouth of the smoker when theheated tobacco product 50 is in use, and filters the aerosol that has passed through theaerosol generating unit 72. As an example,capsules 74 containing a flavoring component or the like are dispersed inside thetip 67, but thetip 67 need not contain thecapsules 74.
Here, the inhalation sensation of the heated tobacco product is preferably close to that of a normal cigarette. Thus, similar to the tip of a normal cigarette, thetip 67 is constituted by aCA band 64 formed by layering and crimping a plurality ofCA filaments 61 in a bundle shape.
The length of the tip 67 (the dimension of thetip 67 in the insertion direction with respect to theinsertion port 51a of the heated tobacco product 50) can be set as appropriate, and for example, is set to a value in a range of not less than 5 mm and not greater than 35 mm, for example. In addition, the length of thetip 67 can be set to a value in a range with a lower limit of any one of 5 mm, 7 mm, or 10 mm and an upper limit of any one of 17 mm, 20 mm, 25 mm, 28 mm, 30 mm, or 35 mm.
The pressure drop (PD) of thetip 67 is proportional to the length of thetip 67. Therefore, the pressure drop of thetip 67 to be produced can be calculated by comparing the length of thetip 67 to the length of atip 67 with a known pressure drop. The circumferential length of thetip 67 can be set as appropriate, and as one example, is set to a value greater than 19 mm as an example. In the present embodiment, the circumferential length is set to 24.5 mm.
When using theheated tobacco product 50, a smoker inserts theaerosol generating article 52 into the interior of the heatedtobacco product unit 51 from theinsertion port 51a and operates theoperation unit 58 to turn on the heatedtobacco product unit 51.
As a result, thecontrol unit 56 controls the power supply circuit to heat theheating unit 57 by the power from thepower supply 54. When a predetermined amount of time has passed while theheating unit 57 is heated to a predetermined temperature, thecontrol unit 56 is configured to notify the smoker through thedisplay unit 55 that theheated tobacco product 50 can be smoked.
The smoker then holds thetip 67 in the smoker's mouth and inhales, and thereby volatile components volatilized from thesubstrate 70 heated by theheating unit 57 flow through theseparator pipe 71. The volatile components that have passed through theseparator pipe 71 are cooled and condensed when flowing through the gap of theaerosol generating unit 72. As a result, an aerosol (droplets) containing volatile components is generated.
Aerosol that has passed through theaerosol generating unit 72 is properly filtered in thetip 67 and inhaled by the smoker. The collision of the aerosol with theCA band 64 used in thetip 67 further reduces the temperature of the aerosol, which is then inhaled by the smoker.
Here, theCA filament 61 contained in thetip 67 has a hollow cross-sectional shape, and therefore the Feret area of theCA filament 61 can be increased compared to filaments having, for example, a Y-shaped cross section. As a result, the shape-irregularity of theCA filament 61 can be adjusted to an appropriate value. Thus, with thetip 67 that uses aCA band 64 containing theCA filaments 61, the filtration degree of the aerosol can be appropriately suppressed, and the amount of aerosol that is collected can be reduced. In addition, adjusting the shape-irregularity of theCA filament 61 to a suitable value improves flow of gas within thetip 67, thereby suppressing the PD of thetip 67.
Also, the number ofCA filaments 61 of theCA band 64 included in thetip 67 need not be reduced to suppress the filtration degree of the aerosol, and therefore a decrease in hardness of thetip 67 due to a reduction in the number ofCA filaments 61 can be suppressed.
Moreover, for a given cross-sectional area of the filament, the diameter of theCA filament 61 can be larger than that of a filament having a solid core portion, and therefore the bending moment of theCA filament 61 can be increased. Thereby, the rigidity of theCA filament 61 can be increased, and a decrease in hardness of thetip 67 can be favorably suppressed.
The filament denier is set to a value in a range of not less than 5.0 and less than 30.0, thereby preventing the gap between fibers from being excessively large. Thus, for example, the matter of a foreign substance entering into the gap between fibers and passing therethrough can be prevented. Also, if thecapsules 74 containing a flavoring component are dispersed in thetip 67, fragments of thecapsules 74 are prevented from flowing through the gaps between fibers, and the contents of thecapsules 74 are prevented from passing through thetip 67 all at once. Setting the filament denier to such a value also prevents the aerosol from flowing through the gap between fibers and passing through thetip 67 without being sufficiently cooled.
In addition, in theCA filament 61, anopening portion 61c that communicates with thecore portion 61a from the outside is formed in theperipheral portion 61b. The porosity (%) of theCA filament 61 is set to a value in a range of not less than 0 and not greater than 20. With this configuration, the surface area, cross-sectional area, and cross-sectional shape of theCA filament 61 can be easily adjusted.
Moreover, the circumferential length L1 of theCA filament 61 is set to a value in a range of not greater than 1/3 of the diameter of theCA filament 61. With this configuration, the surface area, cross-sectional area, and cross-sectional shape of theCA filament 61 can be easily adjusted, and the rigidity of theCA filament 61 can be easily ensured.
The total denier is set to a value in a range of not less than 5000 and not greater than 50000. Thus, the number of filaments during crimping is set to a relatively large number, and thereby each filament can be stably crimped.
Furthermore, with thetip 67, the use of theCA band 64 described above can realize a heated tobacco product tip in which the pressure drop and filtration degree of the aerosol are suppressed while a decrease in hardness is also suppressed.
In a heated tobacco product tip, capsules may be included as in the present embodiment. However, the inclusion of capsules may increase the PD. In thetip 67 of the present embodiment, the use of theCA filament 61 suppresses the PD, and therefore the PD is less likely to increase even if thecapsules 74 are included in theCA band 64. Accordingly, the addition of thecapsule 74 can enhance the design
flexibility of thetip 67.
Furthermore, the shape of the cross section of theCA filament 61 is annular, and the plurality ofCA filaments 61 in thetip 67 are in surface contact with each other at the circumferential surface and firmly bonded to each other by a plasticizer. As a result, thetip 67 has better strength and hardness compared to a tip in which a plurality of filaments having a typical Y-shaped cross section are bonded.
Furthermore, in the spinning, theCA filament 61 which has theopening portion 61c that communicates with thecore portion 61a from the outside, the openingportion 61c being formed in theperipheral portion 61b, is spun, and therefore the surface area, cross-sectional area, and cross-sectional shape of theCA filament 61 can be easily adjusted.
Also, in the spinning, theCA filament 61 is spun by extruding thespinning dope 60 from theorifices 15a having a circular edge shape, in an atmosphere set at a temperature in a range not lower than 40°C and not higher than 80°C. As a result, the surface area, cross-sectional area, and cross-sectional shape of theCA filament 61 can be easily adjusted, and by adjusting the temperature while using a typical spinning device, theCA filaments 61 can be favorably spun.

[Tip cave-in]

FIG. 5 is a diagram for describing the cave-in of a heatedtobacco product tip 167. The heatedtobacco product tip 167 is configured by winding a rolledpaper 40 around acrimped band 164 that has been formed into a rod shape as described above. Inside the rolledpaper 40, a force that expands in the radial direction of thetip 167 and a force that contracts in the axial direction of thetip 167 act on theband 164.
Here, in a case where the force that theband 164 expands in the radial direction of thetip 167 is sufficiently large, theband 164 is pressed against the inner circumferential surface of the rolledpaper 40, and thereby generating a frictional force. The frictional force causes theband 164 to counter the contraction force of thetip 167 in the axial direction, thereby preventing a positional deviation of theband 164 with respect to the rolledpaper 40.
However, in a case where the force that theband 164 expands in the radial direction of thetip 167 is small, the frictional force generated by theband 164 being pressed against the inner circumferential surface of the rolledpaper 40 also decreases. As illustrated inFIG. 5, a decrease in frictional force makes it difficult for theband 164 to counter the contraction force of thetip 167 in the axial direction. As a result, cave-in may occur when both end surfaces of theband 164 in the axial direction of thetip 167 shift inward relative to the both ends of the rolledpaper 40 in the axial direction of thetip 167.
Such problems become significant when the shape-irregularity of the filaments of theband 164 become too small, for example, when the amount of thebands 164 packed into thetip 167 is reduced in order to suppress the PD of thetip 167.
In contrast, theCA filament 61 of the present embodiment has the cross-sectional shape described above, thereby maintaining the appropriate shape-irregularity. As a result, the pressure drop in thetip 67 is reduced, and therefore a good inhalation sensation can be obtained even without reducing the amount ofCA bands 64 packed into thetip 67. Thus, the frictional force generated by theCA band 64 being pressed against the inner circumferential surface of the rolledpaper 40 is not too small, and the cave-in described above can be prevented. Accordingly, thetip 67 can be produced with excellent appearance while maintaining a constant level of quality.
A heated tobacco product tip has a shorter length than an ordinary cigarette tip. Therefore, in a case where capsules are to be included in the tip, when the packing amount of the band in the tip is low, cave-in may occur, and it may be difficult to uniformly arrange the capsules in the length direction of the tip. However, in the present embodiment, cave-in of thetip 67 is prevented, and therefore thecapsules 74 can be evenly arranged in the longitudinal direction of thetip 67. Another embodiment will be described below focusing on differences from the first embodiment.

(Second Embodiment)

FIG. 6 is a front view of anorifice 115a formed in aspinneret 115 according to a second embodiment. According to the second embodiment, in the spinning, the spinningdope 60 is extruded from theorifice 115a having an edge shape with anotch 115b in a part of the edge, and thereby the CA filament 61 (seeFIG. 2) is spun with the openingportion 61c that communicates with thecore portion 61a from the outside, the openingportion 61c being formed in theperipheral portion 61b.
Theorifice 115a has an edge shape corresponding to a boundary of a shape enclosed by line segments corresponding to two radius r1 and an arc M therebetween, in a first imaginary circle having the radius r1 and centered on a point O1. As an example, a center angle θ of theorifice 115a is set to a value (240° in the present embodiment) in a range of greater than 180° and less than 270°.
With this type of production method as well, aCA filament 61 similar to that of the first embodiment can be obtained. In addition, the surface area, cross-sectional area, and cross-sectional shape of theCA filament 61 can be easily adjusted by extruding thespinning dope 60 from theorifices 115a having an edge shape with a notch 11b in a part of the edge. Furthermore, when a typical spinning device, in which the spinneret is replaced with the spinneret having an orifice of the shape described above, is used,CA filament 61 having a hollow cross-sectional shape and with acore portion 61a hollowed and aperipheral portion 61b surrounding thecore portion 61a can be favorably spun.

(Third Embodiment)

FIG. 7 is a front view of aorifice 215a formed in aspinneret 215 according to a third embodiment. Theorifice 215a has a cross section, an edge shape of the cross section corresponding to a boundary of a remaining portion of a second imaginary circle centered on a point O2, the remaining portion being formed by linearly cutting out a portion of the second imaginary circle. As a result, the edge shape of theorifice 215a has anotch 215b in a part of the edge. A distance D1 between one end and the other end of thenotch 215b is smaller than a diameter D2 of the second imaginary circle. As an example, the distance D1 is set to a value in a range of greater than 1/2 of the diameter D/2 and less than 4/5 of diameter D2.
FIG. 8 is a cross-sectional view of aCA filament 161 spun by theorifice 215a inFIG. 7. Thefilament 161 has a cross section, an edge shape of the cross section corresponding to a boundary of a remaining portion of a third imaginary circle having a radius r2 and centered on a point O3, the remaining portion being formed by cutting out a portion of a periphery of the third imaginary circle by a fourth imaginary circle of a diameter D4. In this edge shape, an open end of the portion cut out by the fourth imaginary circle has a smooth curved shape. The radius r2 is greater than the diameter D4. With this configuration, thefilament 161 has acore portion 161a hollowed and anopening portion 161c.

(Fourth Embodiment)

FIG. 9 is a front view of anorifice 315a formed in aspinneret 315 according to a fourth embodiment. Theorifice 315a has an edge shape corresponding to a boundary of an overall shape formed by each of the following remaining portions, the remaining portions being disposed to maximize an area of the overall shape while aligning linear edge portions of each remaining portions to be in mutually parallel. The remaining portions include: a remaining portion formed by linearly cutting out a portion of a fifth imaginary circle centered on a point O4; a remaining portion formed by linearly cutting out a portion of a sixth imaginary circle centered on a point O5; and a remaining portion formed by linearly cutting out a portion of a seventh imaginary circle centered on a point O6.
A diameter D6 of the fifth imaginary circle is greater than a diameter D7 of the sixth imaginary circle and greater than a diameter D8 of the seventh imaginary circle. As a result, the edge shape of theorifice 315a is smooth as a whole and has anotch 315b in a part of the edge. As an example, the diameter D7 and the diameter D8 are the same.
FIG. 10 is a cross-sectional view of aCA filament 261 spun by theorifice 315a ofFIG. 9. Similar to theCA filament 61, theCA filament 261 has a hollow cross-sectional shape with acore portion 261a hollowed and aperipheral portion 261b that surrounding thecore portion 261a. TheCA filament 261 has anopening portion 261c. Thus, even when theorifice 315a is used, aCA filament 261 having the same cross-sectional shape as that of the first embodiment can be obtained.

(Confirmation Test)

A confirmation test will be described next, but the present invention is not limited to the examples introduced below.
ACA filament 61 according to Example 1 was produced through the following procedure. Namely, first, cellulose diacetate having an average degree of acetylation of 55.2% was dissolved in acetone and aspinning dope 60 having a concentration of approximately 25 mass% was prepared.
The spinningdope 60 was then supplied to thespinneret 15 of the first embodiment with the spinningdope 60 adjusted to a temperature from 50 to 60°C.The spinning dope 60 was extruded into thecabinet 14 from theorifices 15a of thespinneret 15, theorifices 15a having a circular edge shape, andCA filaments 61 having an FD of 8.6 and a cross-sectional shape as illustrated inFIG. 2 (C-shape) were spun. The temperature of the atmosphere inside the spinningcabinet 14 was set to a value in a range of not lower than 40°C and not higher than 80°C.
An oil emulsion was applied by alubrication unit 5 to ayarn 62 discharged from thecabinet 14, and theyarn 62 was wound by agodet roll 6. Anend 63 formed by layering theyarns 62 was crimped by a crimpingdevice 9 and dried by a dryingdevice 10. As a result, aCAband 64 of Example 1 was obtained.
A CA filament according to Comparative Example 1 was obtained in the same manner as Example 1 with the exception that the temperature at which hot air was blown into thecabinet 14 and the temperature of the atmosphere inside thecabinet 14 were set to each of the values shown in Table 1. As a result, the cross-sectional shape of the CA filament of Comparative Example 1 was set to a shape with a Feret area of 7.7 (hereinafter, also referred to as an "R" shape). Using this CA filament, a band of Comparative Example 1 was obtained with the same method as that of Example 1.
A CA filament according to Comparative Example 2 was obtained in the same manner as Example 1 with the exception that a spinneret having orifices having a triangular edge shape was used, and the temperature at which hot air was blown into thecabinet 14 and the temperature of the atmosphere inside thecabinet 14 were set to each of the values shown in Table 1. As a result, the cross-sectional shape of the CA filament of Comparative Example 2 was set to a Y-shape. Using this CA filament, a band of Comparative Example 2 was obtained with the same method as that of Example 1.

[Feret Area]

Filament samples were prepared from the CA bands of Example 1 and Comparative Examples 1 and 2 through the following procedure. Namely, fiber bundles were partially picked from the CA band, the fiber bundles were arranged as a long core , and the outer circumference of the core was embedded with paraffin. The filament samples thus prepared were cut with a microtome to a thickness in a range of not thinner than 1 µm and not thicker than 10 µm, and sample slices were obtained.
The sample slices were observed under an optical microscope ("BX-51", available from Olympus Corporation), and images obtained from the observation were input into an image processing device. In the image processing device, an imaginary parallelogram circumscribing a cross section of one CA filament included in the image was set, and the cross-sectional area of the CA filament and the area of the imaginary parallelogram were measured. The Feret area of the CA filament was calculated from the measurements obtained for the cross-sectional area of the CA filament and the area of the imaginary parallelogram.

[S/W Ratio]

The sample slices of Example 1 and Comparative Examples 1 and 2 were observed using the optical microscope, and the images obtained by the observation were input into the image processing device. A cross-sectional area S of one CA filament included in the image and a maximum dimension W, a maximum value of the diameter in the cross-section were measured with the image processing device. The maximum dimension W was the dimension at which the linear distance across the cross section was the greatest. The S/W ratio of the CA filament was calculated from the measurements for the cross-sectional area S and the maximum dimension W of the CA filament.

[Pressure Drop]

Filter rod (plug) samples were prepared using the CA bands of Example 1 and Comparative Examples 1 and 2 through the following procedure. Namely, the CA bands of Example 1 and Comparative Examples 1 and 2 produced using the CA band production apparatus were gathered to a bundle with a predetermined diameter using a tip production apparatus. Each CA band was molded into a rod shape, a rolled paper was wound around the outer circumference thereof, and the rolled paper was fixed to the CA band, and thereby a filter rod sample was obtained.
The filter rod sample was set to a length of the rod of 140 mm, a circumferential length of 22.62 mm, and a packing amount (net tow weight) of 0.52 g/rod. The produced filter rod sample was stored in an air-conditioned room set to a temperature of 20°C and a humidity of 65% for 24 hours to thereby acclimate the filter rod sample.
Next, air adjusted to a temperature of 22±1°C and a humidity of 60±10% was passed longitudinally through the filter rod sample at a flow rate of 17.5 cc per second. The pressure difference [mmWG] (millimeter water gauge) between both ends of the filter rod sample at this time was measured as the pressure drop. Note that the filter rod sample did not have a through-hole penetrating through the rolled paper.

[Nicotine Filtration Rate]

Cigarette samples were prepared from the CA bands of Example 1 and Comparative Examples 1 and 2 through the following procedure. Specifically, each filter rod sample was cut in the radial direction, and a tobacco leaf portion of a cigarette with a filter ("Peace Light" available from Japan Tobacco Inc.) was connected to the cut piece to thereby fabricate a cigarette sample having a tip (length of 25 mm).
This cigarette sample was smoked using a rotary smoking machine ("MR20D", available from Borgwaldt KC), and the volatile components containing nicotine were filtered through a Cambridge filter placed on the tip of the cigarette sample and on a mouth-end side. The total amount of volatile components from the tobacco leaf portion in the cigarette sample was measured from the weight difference of the tip and the Cambridge filter before and after smoking.
Thirty ml of methanol and 4 mL of an anethole (0.65 g)/methanol (1000 mL) mixed solution were mixed, the tip and the Cambridge filter were immersed in the mixture and subjected to an ultrasonic waves for 30 minutes using an ultrasonic washer, and the volatile components were extracted. The moisture content in each of the extracts was measured using a moisture meter ("Karl Fischer Moisture Meter (model CA-06)" available from Nippon Sokki Co., Ltd.).
The amount of nicotine was measured using a gas chromatograph ("GC-2014 Gas Chromatograph" available from Shimadzu Corporation). Using the following equation, the nicotine filtration rate was calculated from the measurements obtained for the total volatile component amount, water content, and amount of nicotine. $Nicotine Filtration Rate = FTN / (FTN + CFN)$
FTN is the amount of nicotine at the tip, and CFN is the amount of nicotine at the Cambridge filter.

[Filament Rigidity]

The secondary (bending) moment of the CA filaments was calculated from the images of the sample slices of Example 1 and Comparative Examples 1 and 2. The secondary moment was calculated by calculating the area of the CA filament appearing in the image, and then multiplying a coefficient to the square of the calculated area.

[Packing Amount]

The packing amount of the CAband was measured when the tips of the cigarette samples of Example 1 and Comparative Examples 1 and 2 were produced. Table 1 shows the CA band properties, the filter rod sample (cigarette sample) properties, and measurement results for Examples 1 and Comparative Examples 1 and 2. In Table 1, the rigidity of the CA filament and the amount of the CAband packed into the tip are denoted as relative values with respect to the values of Comparative Example 2.

[Table 1]

	Example 1	Comparative Example 1	Comparative Example 2
Hot air blowing temperature (°C)	Values in a range not lower than 70 and not higher than 80	97	97
Temperature (°C) of atmosphere in cabinet	Values in a range not lower than 40 and not higher than 80	Values in a range not lower than 50 and not higher than 97	Values in a range not lower than 50 and not higher than 97
Cross-sectional shape of CA filament	FIG. 2	R-shape	Y-shaped
Feret area	0.58	0.71	0.42
S/W (when FD is 8.6)	21	23	17
PD (mmWG)	Equivalent to Comparative Example 1	97	150
Nicotine filtration rate (%)	Equivalent to Comparative Example 1	20	28.5
CA filament rigidity (when Comparative Example 2 is 15)	12	10	15
Packing amount (when Comparative Example 2 is 100)	110	120	100

As shown in Table 1, the Feret area of Example 1 was found to be a value between the Feret areas of Comparative Example 1 and Comparative Example 2. It was also found that the PD and nicotine filtration rates of Example 1 were both equivalent to the values of Comparative Example 1, and were significantly suppressed compared to the values of Comparative Example 2.
In Example 1, it is thought that the suppression of the Feret area compared to Comparative Example 1 resulted in an improvement in the flow of the aerosol inside thetip 67 and in a reduction in the PD and nicotine filtration rate.
TheCA filament 61 of Example 1 exhibited a rigidity value that was between the rigidity values of the CA filaments of Comparative Example 1 and Comparative Example 2, and the packing amount of Example 1 was found to be a value between the packing amounts of Comparative Example 1 and Comparative Example 2.
From these results, in Example 1, the rigidity of theCA filament 61 was greater than the rigidity of the CA filament of Comparative Example 1, and therefore it is thought that theCA filament 61 can be favorably crimped while preventing the occurrence of cracking or fluffing (flying) of theCA filament 61 when crimping is performed, and that the hardness of thetip 67 can be maintained at a high level.
Furthermore, in Example 1, it is thought that the relatively low PD made it possible to achieve a packing amount that was greater than the packing amount of Comparative Example 2 and comparable to the packing amount of Comparative Example 1. It is also thought that as a result, in Example 1, it was possible to favorably maintain the hardness of thetip 67 while preventing the occurrence of cave-in.
Next, aCA filament 61 of Example 2 was obtained in the same manner as in Example 1 with the exception that thespinneret 115 illustrated inFIG. 6 was used, and the temperature at which hot air was blown into thecabinet 14 and the temperature of the atmosphere inside thecabinet 14 were set to the values shown in Table 2.
ACA filament 161 according to Example 3 was obtained in the same manner as in Example 1 with the exception that thespinneret 215 illustrated inFIG. 7 was used, and the temperature at which hot air was blown into thecabinet 14 and the temperature of the atmosphere inside thecabinet 14 were set to the values shown in Table 2.

ACA filament 261 according to Example 4 was obtained in the same manner as Example 1 with the exception that thespinneret 315 illustrated inFIG. 9 was used, and the temperature at which hot air was blown into thecabinet 14 and the temperature of the atmosphere inside thecabinet 14 were set to the values shown in Table 2. The maximum diameter of the orifices, the FD, and the diameter of the CA filaments set in Examples 2 to 4 are shown in Table 2.

[Table 2]

	Example 2	Example 3	Example 4
Hot air blowing temperature (°C)	97	Values in a range not lower than 70 and not higher than 80	97
Temperature (°C) of atmosphere in cabinet	Values in a range not lower than 50 and not higher than 97	Values in a range not lower than 40 and not higher than 80	Values in a range not lower than 50 and not higher than 97
Maximum diameter (µm) of orifice	120	70	143
Edge shape of orifice	FIG. 6	FIG. 7	FIG. 9
Cross-sectional shape of CA filament	FIG. 2	FIG. 8	FIG. 10
FD	15	7	20
Diameter (µm) of CA filament	45	25	45

As shown in Table 2, from the results of Examples 2 to 4, it was confirmed that theCA filaments 61, 161 and 261 were spun with an FD set to a value in a range of not less than 7 and not greater than 20 and a diameter set to a value in a range ofnot smaller than 25 µm and not greater than 45 µm.
In the first embodiment, theCAband 64 was used in thetip 67. However, theCA band 64 may be used in a configuration other than thetip 67 of the aerosol generating article 52 (for example, in at least a portion of theseparator pipe 71 or aerosol generating unit 72).

Industrial Applicability

As described above, the present invention has an excellent effect of being able to suppress the pressure drop and the filtration degree of the aerosol while suppressing a decrease in the hardness in a heated tobacco product tip. Accordingly, the present invention is beneficial in a broad range of applications that can exhibit the significance of this effect including in a band for a heated tobacco product tip, a heated tobacco product tip, and a method for producing a heated tobacco product tip band.

Reference Signs List

15a, 115a, 215a, 315a Orifice
40 Rolled paper
50 Heated tobacco product
61, 161, 261 CA filament
61a, 161a, 261a Core portion
61b, 261b Peripheral portion
61c, 161c, 261c Opening portion
64 CA band
65 Molded article
67 Heated tobacco product tip
115b, 215b, 315bNotch

Claims

A band for a heated tobacco product tip (67), the band (64) being a cellulose acetate band (64) formed by layering and crimping a plurality of filaments (61, 161, 261) in a bundle shape, wherein a filament denier is set to a value in a range of not less than 5.0 and less than 30.0, and a total denier is set to a value in a range of not less than 5000 and not greater than 50000;
each of the filaments (61, 161, 261) has a hollow cross-sectional shape with a core portion (61a, 161a, 261a) hollowed and a peripheral portion (61b, 261b) surrounding the core portion (61a, 161a, 261a), and an opening portion (61c, 161c, 261c) that communicates with the core portion (61a, 161a, 261a) from outside and is formed in the peripheral portion (61b, 261b); and
a porosity (%) defined by (L1 / L0) × 100 is set to a value in a range of not less than 0 and not greater than 20,
L0 being a circumferential length of the peripheral portion (61b, 261b) in a cross section of the filament (61, 161, 261) after production, and L1 being a circumferential length of the opening portion (61c, 161c, 261c) in the cross section of the filament (61, 161, 261) after production.
The band for a heated tobacco product tip (67) according to claim 1, wherein the circumferential length of the opening portion (61c, 161c, 261c) in the cross section of the filament (61, 161, 261) is set to a value in a range of not greater than 1/3 of the diameter of the filament (61, 161, 261).
The band for a heated tobacco product tip (67) according to claim 1, wherein the filament (61, 161, 261) has a cross section, an edge shape of the cross section corresponding to a boundary of a remaining portion of an imaginary circle, the remaining portion formed by cutting out a portion of a periphery of the imaginary circle by another imaginary circle having a diameter that is smaller than a radius of the imaginary circle.
A heated tobacco product tip (67) comprising:
a molded article (65) formed by molding the band (64) described in any one of claims 1 to 3 into a rod shape; and
a rolled paper (40) wound around a circumferential surface of the molded article (65).
The heated tobacco product tip (67) according to claim 4, wherein a length is set to a value in a range having a lower limit of any one of 5 mm, 7 mm, or 10 mm, and an upper limit of any one of 17 mm, 20 mm, 25 mm, 28 mm, 30 mm, or 35 mm.
A method for producing a band (64) for a heated tobacco product tip (67), the method comprising:
spinning a plurality of filaments (61, 161, 261); and
layering and crimping, in a bundle shape, the plurality of filaments (61, 161, 261) that have been spun; wherein
in the spinning, a filament denier is set to a value in a range of not less than 5.0 and less than 30.0, and a total denier is set to a value in a range of not less than 5000 and not greater than 50000, and the filaments (61, 161, 261) are spun, each of the filaments (61, 161, 261) having a hollow cross-sectional shape with a core portion (61a, 161a, 261a) hollowed and a peripheral portion (61b, 261b) surrounding the core portion (61a, 161a, 261a), and an opening portion (61c, 161c, 261c) that communicates with the core portion (61a, 161a, 261a) from outside and is formed in the peripheral portion (61b, 261b), and a porosity (%) defined by (L1 / L0) × 100 that is set to a value in a range of not less than 0 and not greater than 20,
L0 being a circumferential length of the peripheral portion (61b, 261b) in a cross section of the filament (61, 161, 261) after production, and L1 being a circumferential length of the opening portion (61c, 161c, 261c) in the cross section of the filament (61, 161, 261) after production.
The method for producing a band (64) for a heated tobacco product tip (67) according to claim 6, wherein, in the spinning, the filaments (61, 161, 261) are spun by extruding a spinning dope (60) from an orifice (15a, 115a, 215a, 315a) having a circular edge shape, in an atmosphere set at a temperature in a range of not lower than 40°C and not higher than 80°C.
The method for producing a band (64) for a heated tobacco product tip (67) according to claim 6 or 7, wherein, in the spinning, the filaments (61, 161, 261) are spun by extruding the spinning dope (60) from an orifice (15a, 115a, 215a, 315a) having an edge shape with a notch (11b, 115b, 215b, 315b) in a part of the edge.
The method for producing a band (64) for a heated tobacco product tip (67) according to any one of claims 6 to 8, wherein, in the spinning, the filaments (61, 161, 261) are spun, each of the filaments (61, 161, 261) having, in a cross section of the filament (61, 161, 261) after production, a circumferential length of the opening portion (61c, 161c, 261c) set to a value in a range of not greater than 1/3 of the diameter of the filament (61, 161, 261).
The method for producing a band (64) for a heated tobacco product tip (67) according to any one of claims 6, 7, and 9, wherein, in the spinning, each of the filaments (61, 161, 261) is spun by extruding the spinning dope (60) from an orifice (15a, 115a, 215a, 315a) having: an edge shape corresponding to a boundary of a shape enclosed by two line segments extending radially from a center of an imaginary circle and an arc (M) of the imaginary circle between the two line segments; and an angle in a range of greater than 180° and less than 270°, the angle being formed by the two line segments around the center of the imaginary circle on an opening side of the orifice (15a, 115a, 215a, 315a).
The method for producing a band (64) for a heated tobacco product tip (67) according to any one of claims 6, 7, and 9, wherein, in the spinning, each of the filaments (61, 161, 261) is spun by extruding the spinning dope (60) from an orifice (15a, 115a, 215a, 315a) having an edge shape corresponding to a boundary of a remaining portion, the remaining portion being formed by cutting out, from an imaginary circle, a portion of the imaginary circle enclosed by a straight line transecting the imaginary circle and an arc (M) between two points on a circumference of the imaginary circle, the two points being intersections of the straight line and the imaginary circle; such that each of the filaments (61, 161, 261) has a cross section, an edge shape of the cross section corresponding to a boundary of a remaining portion formed by cutting out a portion of a periphery of an imaginary circle by another imaginary circle having a diameter that is smaller than a radius of the imaginary circle.
The method for producing a band (64) for a heated tobacco product tip (67) according to any one of claims 6, 7, and 9, wherein, in the spinning, each of the filaments (61, 161, 261) is spun by extruding the spinning dope (60) from an orifice (15a, 115a, 215a, 315a) having an edge shape corresponding to a boundary of an overall shape formed by a first remaining portion, a second remaining portion, and a third remaining portion;
the first remaining portion being formed by cutting out, from a first imaginary circle, a portion of the first imaginary circle enclosed by a straight line transecting the first imaginary circle and an arc (M) between two points on a circumference of the first imaginary circle, the two points being intersections of the straight line and the first imaginary circle;
the second remaining portion being formed by cutting out, from a second imaginary circle, a portion of the second imaginary circle enclosed by a straight line transecting the second imaginary circle and an arc (M) between two points on a circumference of the second imaginary circle, the two points being intersections of the straight line and the second imaginary circle;
the third remaining portion being formed by cutting out, from a third imaginary circle, a portion enclosed by a straight line transecting the third imaginary circle and an arc (M) between two points on a circumference of the third imaginary circle, the two points being intersections of the straight line and the third imaginary circle; and
the first, second, and third remaining portions being disposed to maximize an area of the overall shape while aligning linear edge portions of each remaining portions to be in mutually parallel.