EP4699454A1

EP4699454A1 - Twisted yarn-like material for smoking article

Info

Publication number: EP4699454A1
Application number: EP23934130.8A
Authority: EP
Inventors: Kimitaka UCHII; Masahiro Chida
Original assignee: Japan Tobacco Inc
Current assignee: Japan Tobacco Inc
Priority date: 2023-04-19
Filing date: 2023-04-19
Publication date: 2026-02-25
Also published as: WO2024218988A1; CN121263076A; KR20250166335A; JPWO2024218988A1

Abstract

Provided is a twisted yarn-like material for a smoking article, the material comprising a base material for a smoking article, the base material being selected from the group consisting of a sheet provided with a slit, a strand, and a combination thereof. A bundle body of the base material is twisted so as to face a direction obliquely crossing the length direction thereof.

Description

TECHNICAL FIELD

The present invention relates to a twisted yarn-like material for smoking articles.

BACKGROUND ART

Non-combustion type smoking articles, which have been growing in popularity in the smoking market in recent years, generally heat a tobacco rod by means of a heating implement at 150 to 350°C, to thereby distill and deliver flavor components. Tobacco rods are produced by a conventional method of filling with shredded tobacco sheets, a method of filling with tobacco sheets that have been cut into strips in the longitudinal direction, or a method of filling with sheets that have been crimped in an as-is state. In each method, gaps are provided to ensure a desired aerosol flow passage during smoking. For example, PTL 1 discloses producing an aerosol generating article by unwinding a tobacco sheet wound on a first bobbin and a tobacco sheet wound on a second bobbin from the respective bobbins, and at this time merging each strand while maintaining an angle of 5 to 90 degrees.

CITATION LIST

PATENT LITERATURE

PTL 1: Japanese Patent No. 6959224

SUMMARY OF INVENTION

TECHNICAL PROBLEM

Although a flavor source rod such as a tobacco rod requires gaps to allow the aerosol to flow, gaps reduce the hardness of the rod. In view of these circumstances, the present invention addresses the problem of providing a flavor source rod having an appropriate hardness.

SOLUTION TO PROBLEM

The inventors have found that a twisted yarn-like material solves the above problems. That is, the restoring force resulting from the twisted structure imparts stiffness to the rod. Therefore, the above problem is solved by the following invention.

Aspect 1

A twisted yarn-like material for smoking articles, including a smoking article substrate selected from the group consisting of a sheet provided with slits, strands, and combinations thereof, wherein
a bundle of the substrate is twisted so as to face in a direction that obliquely intersects the longitudinal direction thereof.

Aspect 2

The material set forth in aspect 1, wherein the thickness of the sheet is 50 to 2000 µm, or
the thickness of the strands is 50 to 2000 µm.

Aspect 3

The material as set forth in aspect 1 or 2, wherein the slit width of the sheet or the cut width of the strands is 0.5 to 10 mm.

Aspect 4

The material as set forth in any one of aspects 1 to 3, wherein the substrate includes a flavor source.

Aspect 5

The material as set forth in aspect 4, wherein the flavor source is derived from tobacco.

Aspect 6

The material as set forth in any one of aspects 1 to 5, wherein an angle between the longitudinal axis and ridge lines caused by the twisting is 10 to 40 degrees.

Aspect 7

The material as set forth in any one of aspects 1 to 6, wherein the substrate is derived from a cast sheet, an extruded sheet, or a laminated sheet.

Aspect 8

A flavor source rod including the material as set forth in any one of aspects 1 to 7.

Aspect 9

The flavor source rod as set forth in aspect 8, wherein, if C is the center of a cross section perpendicular to the longitudinal direction of the flavor source rod and R is the radius thereof:

if D is the filling density of an area above 0.7R and up to R, and
d is the filling density of an area from C to 0.7R,
D>d.

Aspect 10

A smoking article including the flavor source rod as set forth in aspect 8 or 9.

Aspect 11

A method for producing the material as set forth in any one of aspects 1 to 7, including: a step of preparing a bundle of the substrate; and
a step of twisting the bundle in a direction of rotation about the longitudinal axis thereof.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention makes it possible to provide a flavor source rod having an appropriate hardness.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a diagram illustrating an overview of a smoking article substrate
Fig. 2 is a diagram illustrating an overview of a smoking article substrate
Fig. 3 is a diagram illustrating the filling density of each area
Fig. 4 is a diagram illustrating an embodiment of a heat-not-burn smoking article
Fig. 5 is a diagram illustrating an embodiment of a heat-not-burn smoking system
Fig. 6 shows the appearance of flavor source rods obtained in the examples and comparative examples

DESCRIPTION OF EMBODIMENTS

The present invention is described in detail below. In the present invention, the range "X to Y" includes X and Y as the end values.

1. Twisted yarn-like material

The twisted yarn-like material according to the present embodiment is for use in smoking articles, and includes a smoking article substrate selected from the group consisting of a sheet provided with slits, strands, and combinations thereof, wherein a bundle of the substrate is twisted so as to face in a direction that obliquely intersects the longitudinal direction thereof. A smoking article is an article that generates an aerosol by combustion or heating. The former is also referred to as a combustion-type smoking article and the latter as a heat-not-burn smoking article. The twisted yarn-like material according to the present embodiment is suitable for heat-not-burn smoking articles.

(1) Smoking article substrate

A smoking article substrate is a substrate for use in smoking articles. In the present embodiment, the substrate is selected from the group consisting of a sheet with slits, strands and combinations thereof.

[Structure]

Fig. 1 shows the substrate. S1 denotes a sheet with slits, S11 denotes a slit and S3 denotes a strand. The slits refer to incisions that do not extend to either end of the sheet. The width t of the strands (in the case of a sheet provided with slits, the distance between the slits) influences the restoring force when twisted into a rod. In this respect, the width is preferably 0.5 to 10 mm. The lower limit is preferably 0.8 mm, 1 mm, or 2 mm or more, and the upper limit is preferably 8 mm, 5 mm or 4 mm or less.
The longitudinal length of the sheet or strands is not limited, but is preferably 0.5 to 2 cm. The thickness of the sheet or strands is not limited, but is preferably 50 to 2000 µm. The width (lateral direction length) and number of sheets, and the width and number of strands, are set as appropriate depending on the thickness of the rod that is ultimately to be obtained.
The substrate is bundled into a rod shape, forming a bundle (fig. 2). In the drawing, S' is the bundle and S is the twisted yarn-like material. At this time, if strands are used as the substrate, a plurality of strands are arranged parallel to each other. "Arranged parallel to each other" refers to an arrangement in which the longitudinal direction of each strand is substantially parallel to the longitudinal direction of the rod. Furthermore, the start and end of each strand are preferably arranged in alignment. Although the drawing shows a bundle S' employing a plurality of strands, the same applies if a bundle of sheets is used, or if strands and sheets are used together. The bundle is twisted to a direction obliquely intersecting the longitudinal direction thereof, to form the twisted yarn-like material S. In the drawing, r is a ridge line and α is the angle between the longitudinal axis and the ridge line. α is preferably 10 to 40 degrees, and more preferably 15 to 30 degrees. Although not shown in the drawings, the twisted yarn-like material S is wrapped with a wrapper to secure the twisted structure.
As a result of the repulsive force caused by the twisted structure, the flavor source rod has a higher filling density on the outside than on the inside. Specifically, as shown in fig. 3, if C is the center of a cross section perpendicular to the longitudinal direction and R is the radius thereof, then if D is the filling density of an area above 0.7R and up to R, and d is the filling density of an area from C to 0.7R, D>d. A flavor source rod that satisfies this relationship has an appropriate hardness. In this respect, D/d is preferably 0.8 to 8. The filling density can be measured by image analysis. In the figure, 20A is a flavor source rod.
The substrate is preferably derived from a cast sheet, an extruded sheet, or a laminated sheet. These sheets will be described later.

[Flavor source]

The substrate preferably includes a flavor source. A flavor source is a material that emits a flavor. The flavor source is preferably derived from tobacco. Tobacco materials that can be cited as the flavor source include materials derived from plants of the genus Nicotiana. Specific examples of tobacco materials include tobacco shreds and tobacco powder, which are commonly used in the field. These may be used alone or in combination. Tabacum and Rusticana, for example, which belong to the genus Nicotiana, can preferably be used as the tobacco leaf raw material for these tobacco materials. There is no restriction on the variety, etc., and one or more of these tobacco leaves can be used in combination. A suitable blend of the abovementioned varieties may be used in the form of a mixture to achieve the intended taste. A flavor source rod formed from a substrate containing a flavor source derived from tobacco is also referred to as a tobacco rod.

[Other components]

The substrate may contain other components. Examples include aerosol-generating agents. An aerosol-generating agent is a material that vaporizes when heated and cools to generate an aerosol, or that generates an aerosol when atomized. Including an aerosol-generating agent in the substrate allows a sufficient amount of smoke to be provided. Known aerosol-generating agents can be used, and examples thereof that can be cited include polyhydric alcohols such as glycerin, vegetable glycerin, and propylene glycol (PG), triethyl citrate (TEC), and triacetin. In one embodiment, the amount of aerosol-generating agent may be 5 to 20% by weight, and more preferably between 10 and 15% by weight, based on the dry weight of the flavor source. If the amount of aerosol-generating agent exceeds the upper limit, stains or the like may occur on the flavor source rod, and if below the lower limit, the perceived smoke intensity may be reduced.
Furthermore, materials commonly used in the field, such as a molding agent, a reinforcing agent, or a fragrance, may be added to the substrate. A molding agent is a binder that imparts strength to the sheet. Examples of binders include polysaccharides, proteins, and synthetic polymers. These may be used alone or in combination of two or more. Examples of polysaccharides include cellulose derivatives and naturally derived polysaccharides.
A reinforcing agent is added for the purpose of improving the mechanical properties of the sheet. Examples of reinforcing agents include fibrous substances such as fibrous pulp, insoluble fibers, and fibrous synthetic cellulose, and liquid substances having a film-forming surface-coating function, such as a pectin aqueous suspension. These may be used alone or in combination of two or more.
Examples of fragrances include menthol. The amounts of the components described above may be known amounts.

2. Production method

Preferably, the twisted yarn-like material is produced using a method including: a step 1 of preparing a smoking article substrate selected from the group consisting of a sheet provided with slits, strands, and combinations thereof; and a step 2 of twisting a bundle of the substrate to a direction obliquely intersecting the longitudinal direction thereof.

(1) Step 1

In this step, the smoking article substrate is prepared. The substrate is preferably produced by means of a method in which a sheet is produced by a known method such as rolling or casting, and slits are provided in the sheet or the sheet is cut. Details of various types of tobacco sheets produced by such methods are disclosed in "Dictionary of Tobacco, Tobacco Academic Studies Center, March 31, 2009".

Examples of methods that can be cited for producing a sheet by means of rolling include methods comprising the following steps.

1) A step of mixing water, tobacco powder, an aerosol-generating agent, a binder, and a reinforcing agent to obtain a mixture.
2) A step of introducing and rolling the mixture between calendering rollers.
3) A step of drying the rolled product in a dryer.

When a sheet is produced by this method, the surface of the calendering rollers may be heated or cooled, and the rotational speed of the calendering rollers may be adjusted, depending on the intended purpose. The gap between the calendering rollers may also be adjusted. One or more calendering rollers can be used to obtain a tobacco sheet of the desired basis weight.

Methods comprising the following steps can be cited, for example.

1) A step of mixing water, tobacco powder, an aerosol-generating agent, a binder, and pulp to obtain a mixture.
2) A step of spreading thinly (casting) and drying the mixture to form a tobacco sheet.

When a tobacco sheet is produced by this method, a step may be added in which a slurry obtained by mixing water, tobacco powder, an aerosol-generating agent, a binder, and pulp is exposed to ultraviolet or X-ray radiation to remove some components such as nitrosamines.

Methods comprising the following steps can be cited, for example.

1) A step of kneading a tobacco material, a binder and water to prepare a mixture.
2) A step of pressing the mixture flat or extruding the mixture from a die to prepare a wet sheet.
3) A step of drying the wet sheet.

The sheet is cut into strands in the usual way. Alternatively, the sheet is provided with slits in the usual way.

(2) Step 2

This step is preferably carried out by bundling the substrate to prepare a rod-shaped bundle, and twisting the bundle. The twist direction is the circumferential direction of the bundle, i.e., the direction of rotation about the longitudinal axis. As a result of the twisting, the substrate bundle faces in a direction that obliquely intersects the longitudinal direction. The number and shape of the strands used, and the shape and number of sheets used are adjusted as appropriate. That is, if a bundle that satisfies the normal diameter of the flavor source rod is obtained using an individual substrate, the substrate can be used alone. Alternatively, if a bundle that satisfies the normal diameter of the flavor source rod is obtained using a plurality of substrates, a plurality of the substrates must be used. The bundle can be prepared by known methods. For example, the rod-shaped bundle can be prepared by passing the substrate through a bundling tube.
A twist angle β is the angle between the longitudinal axis of the rod and a ridge line of the twisted bundle. Normally, the repulsive force causes β to decrease over time. Consequently, the twisted bundle is secured with a wrapper or the like, and the value that is then reached when β stops changing is the value α. Usually, β stops changing within 30 seconds after the twisting step, and the degree of change is very small.

3. Smoking article

Heat-not-burn smoking articles may be heated by a heating device that is separate from the article, or by a heating device that is integrated with the article. In the type in which the article is heated by a separate heating device, the heat-not-burn smoking article and the heating device are collectively referred to as a "heat-not-burn smoking system." The following description takes a heat-not-burn smoking article (hereinafter simply referred to as a "smoking article") as an example. The smoking article has a cylindrical shape. The length of the circumference of the smoking article is preferably 16 to 27 mm, more preferably 20 to 26 mm, and even more preferably 21 to 25 mm. The total length (the horizontal length) of the smoking article 20 is not particular restricted, but is preferably 40 to 90 mm, more preferably 50 to 75 mm, and even more preferably 50 to 60 mm.
The smoking article 20 consists of a flavor source rod and a filter segment constituting a mouthpiece, these being connected by a connecting portion. Fig. 4 shows an embodiment of a smoking article. The flavor source rod 20A is cylindrical, and the total length (the axial length) thereof is, for example, preferably 5 to 100 mm, more preferably 10 to 50 mm, and even more preferably 10 to 25 mm. The cross-sectional shape of the flavor source rod 20A is not particularly restricted, and may, for example, be circular, elliptical, or polygonal. The flavor source rod 20A includes a twisted yarn-like material S around which a wrapper 22 is wrapped.
The filter portion 20C is cylindrical. The filter portion 20C includes a rod-shaped first segment 25 that is made by being filled with cellulose acetate fibers, and a rod-shaped second segment 26 that is similarly made by being filled with cellulose acetate fibers. The first segment 25 is located on the flavor source rod 20A side. The first segment 25 may have a hollow portion. The second segment 26 is located on the mouthpiece side. The second segment 26 is solid. The first segment 25 comprises a first filling layer (cellulose acetate fibers) 25a and an inner plug wrapper 25b that is wrapped around the first filling layer 25a. The second segment 26 comprises a second filling layer (cellulose acetate fibers) 26a and an inner plug wrapper 26b that is wrapped around the second filling layer 26a. The first segment 25 and the second segment 25 are connected by an outer plug wrapper 27. The outer plug wrapper 27 is bonded to the first segment 25 and the second segment 26 by means of a vinyl acetate emulsion adhesive, for example.
The length of the filter portion 20C may, for example, be 10 to 30 mm, the length of the connecting portion 20B may, for example, be 10 to 30 mm, the length of the first segment 25 may, for example, be 5 to 15 mm, and the length of the second segment 26 may, for example, be 5 to 15 mm. The lengths of these individual segments are examples, and may be modified as appropriate, in accordance with the manufacturability, the required quality, and the length of the flavor source rod 20A, for example. For example, the first segment 25 (center-hole segment) comprises the first filling layer 25a, which has one or a plurality of hollow portions, and the inner plug wrapper 25b, which covers the first filling layer 25a. The first segment 25 has the function of increasing the strength of the second segment 26. The first filling layer 25a of the first segment 25 is, for example, densely filled with cellulose acetate fibers. The cellulose acetate fibers are cured by adding, for example, a triacetin-containing plasticizer in an amount of 6 to 20% by weight relative to the weight of the cellulose acetate. The hollow portion of the first segment 25 may, for example, have an inner diameter of φ 1.0 to 5.0 mm.
The first filling layer 25a of the first segment 25 may, for example, be configured with a relatively high fiber filling density, or may have a fiber filling density similar to that of the second filling layer 26a of the second segment 26 described below. As a result, during inhalation, air or aerosol will flow only through the hollow portion, and virtually no air or aerosol will flow through the first filling layer 25a. If, for example, a smaller reduction in the aerosol component by filtration is desired in the second segment 26, the second segment 26 may be shortened, for example, and the first segment 25 lengthened correspondingly. Replacing the shortened second segment 26 with the first segment 25 is effective in increasing the amount of the aerosol component that is delivered. Since the first filling layer 25a of the first segment 25 is a fiber filling layer, the feeling thereof when touched from the outside during use does not cause the user discomfort.
The second segment 26 comprises the second filling layer 26a and the inner plug wrapper 26b, which covers the second filling layer 26a. The second segment 26 (filter segment) is filled with cellulose acetate fibers at a typical density, and has a typical aerosol component filtration performance. The filtration performance for filtering the aerosol (mainstream smoke) released from the flavor source rod 20A may differ between the first segment 25 and the second segment 26. At least one of the first segment 25 and the second segment 26 may contain a fragrance. The filter portion 20C may have any structure, and may have a structure including a plurality of segments, as described above, or may consist of a single segment. The filter portion 20C may consist of one segment. In this case, the filter portion 20C may consist of either the first segment or the second segment.
The connecting portion 20B is cylindrical. The connecting portion 20B comprises a paper tube 23 obtained by forming cardboard, for example, into a cylindrical shape. The connecting portion 20B may be filled with a cooling member for cooling the aerosol. Examples of cooling members include a sheet of a polymer such as polylactic acid, which can be folded for filling. A supporting portion that prevents the position of the flavor source rod 20A from varying may be additionally provided between the flavor source rod 20A and the connecting portion 20B. The supporting portion may comprise known materials such as a center hole filter as used in the first segment 25.
The flavor source rod 20A, the connecting portion 20B, and the filter portion 20C are connected together integrally by wrapping a wrapper 28 cylindrically around the outsides thereof. One surface (the inner surface) of the wrapper 28 is coated, over the entire surface or substantially the entire surface, except for an area in the vicinity of ventilation hole portions 24, with a vinyl acetate emulsion adhesive. A plurality of ventilation hole portions 24 are formed from the outside by means of laser processing after the flavor source rod 20A, the connecting portion 20B, and the filter portion 20C have been integrated by the wrapper 28.
The ventilation hole portions 24 comprise two or more through-holes that pass through the connecting portion 20B in the thickness direction. The two or more through-holes are formed so as to be arranged radially when viewed from an extension line of the central axis of the smoking article 20. The ventilation hole portions 24 are provided in the connecting portion 20B in the present embodiment, but may be provided in the filter portion 20C. Moreover, in the present embodiment, the two or more through-holes comprising the ventilation hole portions 24 are provided in a single row at constant intervals in one circular pattern, but they may be provided in two rows at constant intervals in two circular patterns, or one or two rows of ventilation hole portions 24 may be provided discontinuously or irregularly. When a user inhales with the mouthpiece held in the mouth, outside air is drawn into the mainstream smoke through the ventilation hole portions 24. However, the ventilation hole portions 24 need not be provided.
A combination of a heat-not-burn smoking article and a heating device for generating an aerosol is also, in particular, referred to as a heat-not-burn smoking system. An example of a such a system is shown in fig. 5. The heat-not-burn smoking system in the drawing comprises a heat-not-burn smoking article 20 and a heating device 30 that heats the flavor source rod 20A from the outside.
The heating device 30 comprises a body 31, a heater 32, a metal tube 33, a battery unit 34, and a control unit 35. The body 31 has a tubular recessed portion 36, and the heater 32 and the metal tube 33 are disposed in positions corresponding to the flavor source rod 20A that is to be inserted thereinto. The heater 32 may be a heater employing electrical resistance, in which electric power is supplied by the battery unit 34 in accordance with an instruction from the control unit 35, which controls the temperature, thereby causing the heater 32 to perform heating. Heat emitted from the heater 32 is transferred to the flavor source rod 20A via the metal tube 33, which has high thermal conductivity. Although the drawing illustrates an embodiment in which the heating device 30 heats the flavor source rod 20A from the outside, the flavor source rod 20A may equally be heated from the inside. The heating temperature of the heating device 30 is not particularly restricted, but is preferably 400°C or lower, more preferably 150 to 400°C, and even more preferably 200 to 350°C. The heating temperature refers to the heater temperature of the heating device 30. In this case, the flavor generating segment 20A is heated to approximately 200 to 350°C.
The flavor source rod 20A may equally be heated from the inside. For example, a needle-type or blade-type heater may be inserted inside the flavor source rod 20A to heat the rod. Alternatively, a susceptor can be arranged inside the flavor source rod 20A and heated by induction heating.
Aspects of implementation are listed below.

Aspect 1

Aspect 2

Aspect 3

Aspect 4

Aspect 5

Aspect 6

Aspect 7

Aspect 8

Aspect 9

Aspect 10

Aspect 11

EXAMPLES

EXAMPLES 1 to 3

(1) Production of laminate sheet

Tobacco leaves were pulverized using a pulverizer (ACM-5 made by Hosokawa Micron Corp.) to obtain leaf tobacco particles having a D90 of 300 µm. D90 was measured using a Mastersizer (manufactured by Malvern). The leaf tobacco particles and Sunrose F30MC (cellulose ether produced by Nippon Paper Industries Co., Ltd.), as a binder, were dry-blended using a mixer. Next, glycerin, as an aerosol generating substrate, and water, as a medium, were added to the dry blend and mixed using a mixer to prepare a wet powder.
The wet powder was kneaded three times at room temperature using a kneader (DG-1, manufactured by Dalton Corp.) to obtain a mixture. The die shape was circular and the screw rotational speed was 60 rpm.
A calendering device (manufactured by Yuri Roll Machine Co., Ltd.) was used to prepare a 250 µm sheet from the wet powder. The roll gap was set to 20 µm. The roll gap is thicker than the thickness of the sheet that was finally obtained, because the sheet expanded to close to the final thickness when released from the pressure between the rollers. The resulting sheet was dried at 80°C for 5 minutes using a ventilation dryer to obtain a laminate sheet.

(2) Production of strands

Laminate sheets produced as described above were cut to produce strands having widths of 0.8 mm, 2 mm, and 4 mm, respectively, and a length of 10 cm.

(3) Production of twisted yarn-like material

A predetermined number of the strands were arranged on a flat plate. At this time, the tips and ends of the strands were aligned. The strands were then bundled and twisted. At this time, the angle β between the longitudinal axis of the strands before twisting and ridge lines caused by the twisting was 40 degrees. The twisted yarn-like material was wrapped using a wrapper while the twisted state was maintained. The tobacco rods obtained in this way were allowed to stand for 10 minutes, after which the appearance was observed. As a result, the angle α between the longitudinal axis and the ridge lines was smaller than β due to torsional repulsive forces.

Comparative Examples 1 to 3

Tobacco rods were produced using the same method as in the examples, except that no twisting was applied, and the appearance was observed.
The results are shown in Table 1 and fig. 6(1). The numbers in the drawing indicate that voids were observed in the core portion of the tobacco rods produced in the examples, and it was clear that the hardness of the tobacco rods had improved. [Table 1-1] Strand width: 0.8 mm

Example 1 Comparative Example 1

-1 -2 -3 -1 -2 -3

Number (strands) 12 20 30 40 50 70 100 12 20 30 40 50 70 100

α (°) 15 15 15 0 0 0

[Table 1-2] Strand width: 2 mm

Example 2 Comparative Example 2

-1 -2 -3 -4 -1 -2 -3 -4

Number (strands) 12 20 30 40 50 70 100 12 20 30 40 50 70 100

α (°) 15 15 15 15 0 0 0 0

[Table 1-3] Strand width: 4 mm

Example 3 Comparative Example 3

-1 -2 -3 -1 -2 -3

Number (strands) 12 20 30 40 50 70 100 12 20 30 40 50 70 100

α (°) 15 15 15 0 0 0

EXAMPLE 4

A rod was produced and evaluated using the same method as in Example 1-2, except that β was set to 60°. The appearances of the resulting rod is shown in fig. 6(2) together with the rods produced in Example 1-2 and Comparative Example 1-2. [Table 2] Strand width: 0.8 mm

Example 4

Number (strands) 70

α (°) 40

REFERENCE SIGNS LIST

S1 Sheet provided with slits
S11 Slit
S3 Strand
t Strand width, distance between slits
S Twisted yarn-like material
S' Bundle
r Ridge line
α Final angle between longitudinal axis and ridge line
C Center of cross section perpendicular to longitudinal direction
R Radius
20 Heat-not-burn smoking article
20A Flavor source rod
20B Connecting portion
20C Filter portion
22 Wrapper
23 Paper tube
24 Ventilation hole portion
25 First segment
25a First filling layer
25b Inner plug wrapper
26 Second segment
26a Second filling layer
26b Inner plug wrapper
27 Outer plug wrapper
28 Wrapper
30 Heating device
31 Body
32 Heater
33 Metal tube
34 Battery unit
35 Control unit
36 Recessed portion
37 Ventilation hole

Claims

A twisted yarn-like material for smoking articles, including a smoking article substrate selected from the group consisting of a sheet provided with slits, strands, and combinations thereof, wherein
a bundle of the substrate is twisted so as to face in a direction that obliquely intersects the longitudinal direction thereof.
The material as claimed in claim 1, wherein the thickness of the sheet is 50 to 2000 µm, or
the thickness of the strands is 50 to 2000 µm.
The material as claimed in claim 1 or 2, wherein the slit width of the sheet or the cut width of the strands is 0.5 to 10 mm.
The material as claimed in any one of claims 1 to 3, wherein the substrate includes a flavor source.
The material as claimed in claim 4, wherein the flavor source is derived from tobacco.
The material as claimed in any one of claims 1 to 5, wherein an angle between the longitudinal axis and ridge lines caused by the twisting is 10 to 40 degrees.
The material as claimed in any one of claims 1 to 6, wherein the substrate is derived from a cast sheet, an extruded sheet, or a laminated sheet.
A flavor source rod including the material as claimed in any one of claims 1 to 7.
The flavor source rod as claimed in claim 8, wherein, if C is the center of a cross section perpendicular to the longitudinal direction of the flavor source rod and R is the radius thereof:
if D is the filling density of an area above 0.7R and up to R, and

d is the filling density of an area from C to 0.7R,

D>d.
A smoking article including the flavor source rod as claimed in claim 8 or 9.
A method for producing the material as claimed in any one of claims 1 to 7, including: a step of preparing a bundle of the substrate; and
a step of twisting the bundle in a direction of rotation about the longitudinal axis thereof.