EP4666881A2

EP4666881A2 - Lyocell material, filter for smoking article, smoking article, and method of preparing the lyocell material

Info

Publication number: EP4666881A2
Application number: EP25183248.1A
Authority: EP
Inventors: Seung Dong SEO; Jong Cheol Jeong; Sang Woo Jin; Eun Young Park; Jeong Hun Lee; Yeong Nam Hwang; Min Hee Hwang; Kyeng Bae Ma; Ki Jin AHN; Jin Chul Yang; Sung Hoon Ha
Original assignee: Kolon Industries Inc; KT&G Corp
Current assignee: Kolon Industries Inc; KT&G Corp
Priority date: 2024-06-17
Filing date: 2025-06-17
Publication date: 2025-12-24
Also published as: WO2025263938A1; KR20250177733A; EP4666881A3

Abstract

The present application relates to a lyocell material, a filter for a smoking article including the lyocell material, and a smoking article. The lyocell material and the filter for a smoking article, according to the present application, may replace a cellulose acetate material and a filter for a smoking article including the same, in the art.

Description

Technical Field

The present application relates to a lyocell material, a filter including the same, a smoking article, and a method of preparing the lyocell material.

Background Art

Until now, cellulose acetate fibers have been mainly used as tobacco filter materials. Cellulose acetate is known to be a biodegradable material, but filters for a smoking article, made of cellulose acetate, remain in their original form for 1 to 2 years even after being buried in soil, and it takes a considerable amount of time for the filters to completely biodegrade. Considering the amount and toxicity of tobacco products that are discarded and left in the living environment as well as tobacco products that are collected as waste after being used for smoking and then buried in a landfill, there is a need to further improve the biodegradability of a filter for a smoking article. Accordingly, lyocell, which is more environmentally friendly, has recently been chosen as a material to replace cellulose acetate.

Disclosure of Invention

Technical Problem

An object of the present application is to provide a lyocell material capable of replacing cellulose acetate commercialized for a filter for a smoking article.
Another object of the present application is to provide a lyocell material for a filter for a smoking article, of which a preparation process is environmentally friendly and which has excellent biodegradability when discarded.
Another object of the present application is to provide a lyocell filter for a smoking article.
Another object of the present application is to provide a smoking article (for example, a cigarette) including a lyocell filter.
Another object of the present application is to optimize a process of preparing a filter from a lyocell material by optimizing a manner in which at least a portion of a lyocell material is unwound during a process of preparing a filter from a lyocell material.
Another object of the present application is to optimize a process of preparing a filter from a lyocell material by optimizing a manner in which at least a portion of a lyocell material is wound from the lyocell material prepared in the form of a stack such as a bale.

Solution to Problem

According to the present invention, there are provided a lyocell material, a filter including the same, a smoking article, and the like.
The lyocell material may include one or more lyocell multifilaments.
The lyocell multifilament may include one or more lyocell monofilaments.
According to the present application, there is provided a lyocell material including one or more lyocell multifilaments imparted with crimps, wherein the lyocell material includes a central portion and one or more side portions and satisfies Expression 1 below: $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$ wherein, in Expression 1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
In addition, there may be provided a filter for a smoking article, which includes a lyocell material in which a ratio of a total weight C₁ of a central portion to a total weight M₁ of side portions is 0.85 or more.
According to another aspect of the present application, there may be provided a smoking article including the lyocell material or the filter.
According to another aspect of the present application, there may be provided a method of preparing the lyocell material, a filter including the same, and a smoking article.
As used herein, the term "smoking article" may refer to an article such as a tobacco (cigarette) or a cigar capable of generating aerosol. In this regard, the smoking article may include an aerosol-generating material or an aerosol-forming substrate. In addition, the smoking article may include a solid material based on a tobacco raw material such as a tobacco leaf, a cut tobacco, or a reconstituted tobacco. In addition, the smoking material may include a volatile compound.
As used herein, the term "lyocell multifilament" may refer to a multifilament made of lyocell cellulose. In particular, the lyocell multifilament may be a (multi)filament and/or fiber made of cellulose derived or mainly derived from wood pulp. In particular, the lyocell multifilament may be a semi-synthetic (multi)filament and/or fiber.
A used herein, the term "cellulose" may refer to "lyocell cellulose".
As used herein, the term "crimp" may refer to a weaved, curled, or undulated configuration imparted to materials such as a fiber, a (mono)filament, a multifilament, and/or yarn inherently or through mechanical, thermal, and/or chemical processes. The crimp may be characterized by a periodic deviation from a straight line axis along a length of a fiber, a (mono)filament, a multifilament, and/or yarn. In the fiber, the (mono)filament, the multifilament, and/or the yarn, one crimp may be defined as one repeating unit of the periodic deviation. The presence of the crimp affects properties such as elasticity, bulk, resilience, and texture of a material and a fabric made of the material.
As used herein, the term "degree of polymerization (DPw)" may refer to the number of monomer units and/or repeating units in a macromolecule, a polymer, or an oligomer molecule. The DPw may be expressed as M_n/M₀, wherein M_n is a number average molecular weight of a macromolecule, a polymer, or an oligomer molecule, and M₀ is a molecular weight of a monomer or a repeating unit.
As used herein, the term "lyocell tow" includes at least one lyocell multifilament or consists of at least one lyocell multifilament.
As used herein, the term "bloomed" lyocell material, fiber, and/or multifilament refer to a lyocell material, a lyocell fiber, and/or a lyocell multifilament that are separated, uncoiled, unspooled, loosened, or unwrapped from an original compressed and/or rolled state.
As used herein, the term "multi-lobal cross section" may refer to a cross-sectional shape that deviates from a standard circular shape. The multi-lobal cross section may include three or more protrusions, for example, three protrusions. Here, the term "protrusion" may refer to a distinct and extended segment or arm extending outward from a central core or junction point of a monofilament cross section. For example, a cross-sectional shape may include a Y-shaped cross section, a rectangular cross section, a star-shaped cross section, a leaf-shaped cross section, a hexagonal cross section, a polygonal cross section, and the like. A multi-lobal cross section including three protrusions may be referred to as a "Y-shaped cross section". Lyocell tow may have a Y-shaped cross section for use in cigarette filters.
As used herein, the term "single fineness of a lyocell multifilament" refers to a fineness of one monofilament separated from a lyocell multifilament. As used herein, the term "single fineness of a filament" is considered as a "single fineness of a lyocell multifilament".
As used herein, the term "basis weight" refers to mass per unit area of wrapping paper and/or wrapper. The basis weight of wrapping paper and/or wrapper may be determined by measuring the mass and area of the wrapping paper and/or wrapper and dividing the mass of the wrapping paper and/or wrapper by the area.
Unless otherwise specifically defined in the present specification, a content (%) of a component may be wt%.
Unless specifically defined otherwise in the specification, when the properties of lyocell materials, filters for a smoking article, and components or compositions related thereto are affected by a temperature, the temperature at which the properties are confirmed or measured may be room temperature. In this case, the room temperature may be a temperature which is not particularly lowered or raised and may be, for example, in a range of 10 °C to 35 °C, In particular in a range of 15 °C to 35 °C or 20 °C to 30 °C, or may be about 25 °C.
The term "vertical length" may be used to refer to a vertical length of the lyocell material when the lyocell material is viewed vertically from above.
The lyocell material may include one or more turning points, and along a length of the lyocell material in the vertical direction that is the direction of the vertical length, the turning points may each be positioned at one of two ends in the vertical direction. The side portion may be a portion closer to one of the two ends, and the central portion may be a portion closer to an exact center point between the two ends than to one of the two ends.
The turning point may be defined as a virtual point at which the lyocell material is turned over. An upper side of the lyocell material, that is a side viewed vertically from above, may be turned before and after the turning point.
The turning point may be defined as a virtual point at which the lyocell multifilament is turned over. An upper side of the lyocell multifilament, that is a side viewed vertically from above, may be turned before and after the turning point.
The term "horizontal length" may be used to refer a horizontal length of the lyocell material when the lyocell material is viewed vertically from above.
The horizontal direction may be the direction of the horizontal length.
The horizontal direction may be orthogonal to the vertical direction.
The horizontal length and the vertical length may be equal to each other. Alternatively, the horizontal length and the vertical length may be different from each other.
The term "central portion" may be used to refer to a central portion of the lyocell material or refer to a portion of the lyocell material disposed at the central portion of the lyocell material. Similarly, the term "side portion" may be used to refer to a side portion of the lyocell material or refer to a portion of the lyocell material disposed at the side portion of the lyocell material. To further emphasize the lyocell material, the term such as "central portion lyocell" or "side portion lyocell" may be used.
The term "central portion" may be used to refer to a central portion of the lyocell material in the vertical direction or refer to a portion of the lyocell material disposed at the central portion of the lyocell material in the vertical direction. Similarly, the term "side portion" may be used to refer to a side portion of the lyocell material in the vertical direction or refer to a portion of the lyocell material disposed at the side portion of the lyocell material in the vertical direction.
In an exemplary lyocell material, among the central portion and the side portion, the side portion may be closer to one end of the lyocell material than the central portion, and the central portion may be closer to a center of the lyocell material than the side portion.
In an exemplary lyocell material, the lyocell material may be understood to include one central portion and two side portions. In addition, each of the side portions may be understood to be positioned at one side of the central portion. In particular, the central portion and the side portions may be included in the order of side portion-central portion-side portion in a longitudinal direction of the lyocell material. The longitudinal direction may be the vertical direction of the lyocell material.
The central portion may be an area that includes about 25 % of the vertical length in both directions from an exact center of the lyocell material in the vertical direction. Similarly, the side portion may be an area that includes about 25 % of the vertical length from one of vertical ends of the lyocell material toward the central portion.
In the lyocell material, among the central portion and the side portion, the side portion is closer to one end of the lyocell material than the central portion, and the central portion is closer to a center of the lyocell material than the side portion.
As used herein, the term "basis weight" refers to mass per unit area of wrapping paper and/or wrapper.
The processability of the lyocell material and the productivity of a filter for a smoking article may be evaluated to be excellent when excessive clumping of the lyocell material of a side portion is not confirmed, and the unwinding of the lyocell material is uniform during a towing.
The processability of the lyocell material and the productivity of a filter for a smoking article may be evaluated to be insufficient and/or poor when excessive clumping of the lyocell material of a side portion is confirmed, and the unwinding of the lyocell material is not uniform during the towing, and, as a result, it is impossible to prepare a filter for a smoking article using the lyocell material.
Hereinafter, the present application is described in more detail.
The present application relates to a lyocell material. The lyocell material may be used in a smoking article, and although not particularly limited, the lyocell material may be used in a filter for a smoking article.
According to the present application, there is provided a lyocell material including one or more lyocell multifilaments imparted with crimps, wherein the lyocell material includes a central portion and one or more side portions and satisfies Expression 1 below. $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%) .$
In Expression 1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
In the lyocell material, among the central portion and the side portion, the side portion is closer to one end of the lyocell material than the central portion, and the central portion is closer to a center of the lyocell material than the side portion.
In each exemplary lyocell material, the lyocell material may include one or more turning points, and along a length of the lyocell material in a vertical direction, the turning points may each be positioned at one of two ends in the vertical direction. The side portion may be a portion closer to one of the two ends, and the central portion may be a portion closer to an exact center point between the two ends than to one of the two ends.
In each exemplary lyocell material, the number of turning points may be 3 to 30 ea.
In each exemplary lyocell material, for example, the number of turning points is 5 to 28 ea.
In each exemplary lyocell material, the number of turning points may be the total number of times at which a stacking direction of the lyocell multifilaments is reversed.
In each exemplary lyocell material, Expression 1 may be satisfied for all of the side portions.
In each exemplary lyocell material, Expression 1-1 may be satisfied. $100 (%) \geq \frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
In Expression 1-1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
In each exemplary lyocell material, Expression 1-1 may be satisfied for all of the side portions.
In each exemplary lyocell material, the total weight of the lyocell multifilaments disposed at the central portion may be less than or equal to the total weight of the lyocell multifilaments disposed at the side portions.
In each exemplary lyocell material, the number of the crimps may be 3.94 ea/cm to 23.62 ea/cm (10 ea/inch to 60 ea/inch).
In each exemplary lyocell material, the number of the crimps may be 9.84 ea/cm to 19.69 ea/cm (25 ea/inch to 50 ea/inch).
In each exemplary lyocell material, a single fineness of the lyocell multifilament may be in a range of 1.67 to 12.22 dtex (1.5 to 11.0 denier).
In each exemplary lyocell material, the single fineness of the lyocell multifilament may be in a range of 2.22 to 6.67 dtex (2.0 to 6.0 denier).
Each exemplary lyocell material may have a total fineness of 1,667 to 6,111 tex (15,000 to 55,000 denier).
The lyocell multifilaments may have a yarn fineness of 1,111 to 4,444 tex (10,000 to 40,000 denier).
Each exemplary lyocell material described above may have a total fineness of 2,222 to 5,556 tex (20,000 to 50,000 denier).
In each exemplary lyocell material, the lyocell multifilament may include one or more monofilaments, and one or more of the monofilaments may have a multi-lobal cross section.
In each exemplary lyocell material, the lyocell multifilament may include one or more monofilaments, and all of the monofilaments may have a multi-lobal cross section.
Each exemplary lyocell material may be lyocell tow.
Each exemplary lyocell material may be used for a filter for a smoking article.
Each exemplary lyocell material may not be used for a tire cord or a garment.
Meanwhile, the term "lyocell material" may be a term including a "stack of lyocell material". To emphasize that a lyocell material has a stacked shape, the term "stack of lyocell material" may be used instead of the term "lyocell material".
In addition, there is provided a filter for a smoking article including any one selected from exemplary lyocell materials.
Furthermore, there is a provided a smoking article including any one selected from respective filters for a smoking article.
In addition, there is provided a method of preparing a lyocell material includes: lyocell dope spinning; coagulation and lyocell multifilament obtainment; washing; emulsion treatment; and crimp imparting and further includes stacking a lyocell material, wherein the stacking is performed by a stacking device, the stacking device includes a body portion and a supply portion capable of performing pendulum motion, and the lyocell material is supplied through the supply portion so that the lyocell material is stacked. In some embodiments, the operations are performed in this stated order.
In an exemplary method of preparing a lyocell material, the stacking may be performed such that Expression 1 below is satisfied. $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
In Expression 1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
In an exemplary method of preparing a lyocell material, the stacking may be performed such that Expression 1-1 below is satisfied. $100 (%) \geq \frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
In Expression 1-1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
In an exemplary method of preparing a lyocell material, the stacking of the lyocell material may be performed by the pendulum motion of the supply portion.
In an exemplary method of preparing a lyocell material, the pendulum motion of the supply portion may be performed at a constant speed.
In an exemplary method of preparing a lyocell material, the pendulum motion of the supply portion may be performed at a variable speed.
In an exemplary method of preparing a lyocell material, a maximum angle of the pendulum motion may be 45° or less.
In an exemplary method of preparing a lyocell material, the maximum angle of the pendulum motion may be 7° or more.
In an exemplary method of preparing a lyocell material, a ratio of a minimum movement speed V_min of the pendulum motion to a maximum movement speed V_max of the pendulum motion may exceed 0.7.
In an exemplary method of preparing a lyocell material, the ratio of the minimum movement speed V_min of the pendulum motion to the maximum movement speed V_max of the pendulum motion may be 1 or less.
A lyocell material according to an exemplary embodiment may include a central portion and one or more side portions and may satisfy Expression 1 below. $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
In Expression 1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
Since the lyocell material satisfies Expression 1, the post-processing properties of the lyocell material, for example, unwinding properties, can be improved. As a result, process costs consumed to prepare a filter for a smoking article can be reduced.
In particular, the lyocell material may be post-processed to be included in a filter for a smoking article. The lyocell material may be transported during or before post-processing. Lyocell materials satisfying Expression 1 can have enhanced transportability. For example, during a process of transporting a lyocell material, the lyocell material can be unwound more uniformly and continuously. As a result, further smooth transport of the lyocell material can be achieved, and any delay in a process of preparing a filter for a smoking article can be prevented.
In addition, the post-processing of the lyocell material may include applying an external force to the lyocell material to induce blooming of the lyocell material. In the case of lyocell materials satisfying Expression 1, the blooming of the lyocell material can occur more smoothly.
In particular, when Expression 1 is satisfied, without the clumping of a lyocell material disposed at a side portion, a degree of unwinding of the lyocell material disposed at the side portion can be identical to a degree of unwinding of a lyocell material disposed at a central portion. As a result, the unwinding and blooming of the lyocell material can occur more uniformly. Furthermore, without excessive or insufficient input of the lyocell material, any delay or stop of a process of preparing a filter for a smoking article can be prevented, and an increase of costs consumed for a process of preparing a filter for a smoking article can be prevented.

[Lyocell material]

According to an example, there is provided a lyocell material including lyocell multifilaments imparted with crimps, wherein the lyocell material includes a central portion and one or more side portions and satisfies Expression 1 below. $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%) .$
In Expression 1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
The term "central portion" may be used to refer to a central portion of the lyocell material or refer to a portion of the lyocell material disposed at the central portion of the lyocell material. Similarly, the term "side portion" may be used to refer to a side portion of the lyocell material or refer to a portion of the lyocell material disposed at the side portion of the lyocell material. To further emphasize the lyocell material, the term such as "central portion lyocell" or "side portion lyocell" may be used.
In an exemplary lyocell material, among the central portion and the side portion, the side portion may be closer to one end of the lyocell material than the central portion, and the central portion may be closer to a center of the lyocell material than the side portion.
In an exemplary lyocell material, the lyocell material may be understood to include one central portion and two side portions. In addition, each of the side portions may be understood to be positioned at one side of the central portion. In particular, the central portion and the side portions may be included in the order of side portion-central portion-side portion in a longitudinal direction of the lyocell material.
The lyocell material may include one or more turning points, and along a length of the lyocell material in a vertical direction, the turning points may each be positioned at one of two ends in the vertical direction. In the lyocell material, the side portion may be a portion closer to one of the two ends, and the central portion may be a portion closer to an exact center point between the two ends than to one of the two ends.
FIG. 1 is a top view of an exemplary lyocell material. In FIG. 1, an appearance of the lyocell material when the lyocell material is observed from above is conceptually shown.
Referring to FIG. 1, the lyocell material 10 is disposed to have a vertical length A. Referring to FIG. 1, a side portion M is a portion positioned closer to (or including) an upper end or a lower end in a vertical direction than a central portion C, and the central portion C is a portion positioned closer to (or including) a center in the vertical direction than the side portion M.
In addition, referring to FIG. 1, it may be regarded that the central portion C is an area that includes about 25 % of the vertical length A in both directions from an exact center of the lyocell material in the vertical direction. Similarly, it may be regarded that the side portion M is an area that includes about 25 % of the vertical length A from one of vertical ends of the lyocell material toward the central portion.
In FIG. 1, the side portions M and the central portion C are illustrated such that a vertical length along which two side portions M are disposed is equal to a vertical length along which one central portion C is disposed.
In addition, in FIG. 1, the lyocell materials are integrally and alternately stacked. When a turning point is defined as a virtual point at which the lyocell material (for example, a lyocell multifilament) is turned over, it may be confirmed that an upper side (a side observed from above) of the lyocell material is turned before and after the turning point. In particular, a total of 15 different turning points may be identified from the lyocell material in FIG. 1.
In each exemplary lyocell material, a ratio of a total weight C₁ of the central portion to the total weight M₁ of the side portions is 85 % or more. In particular, the ratio of the total weight C₁ of the central portion to the total weight M₁ of the side portions may be 86 % or more, 87 % or more, 88 % or more, 89 % or more, 90 % or more, 91 % or more, 92 % or more, 93 % or more, 94 % or more, 95 % or more, 96 % or more, 97 % or more, 98 % or more, 99 % or more, or 100 % or more.
Since the lyocell material satisfies Expression 1, the post-processing properties of the lyocell material, for example, unwinding properties, may be improved. As a result, process costs consumed to prepare a filter for a smoking article may be reduced.
In particular, the lyocell material may be post-processed to be included in a filter for a smoking article. The lyocell material may be transported during or before post-processing. Lyocell materials satisfying Expression 1 can have enhanced transportability. For example, during a process of transporting a lyocell material, the lyocell material can be unwound more uniformly and continuously. As a result, the further smooth transport of the lyocell material can be achieved, and any delay in a process of preparing a filter for a smoking article can be prevented.
In addition, the post-processing of the lyocell material may include applying an external force to the lyocell material to induce the blooming of the lyocell material. In the case of lyocell materials that do not satisfy Expression 1, the blooming of the lyocell material may not occur smoothly.
In particular, when Expression 1 is satisfied, without the clumping of a lyocell material disposed at a side portion, a degree of unwinding of the lyocell material disposed at the side portion can be identical to a degree of unwinding of a lyocell material disposed at a central portion. As a result, the unwinding and blooming of the lyocell material can occur more uniformly. Furthermore, without excessive or insufficient input of the lyocell material, any delay or stop of a process of preparing a filter for a smoking article can be prevented, and an increase of costs consumed for a process of preparing a filter for a smoking article can be prevented.
In each exemplary lyocell material, the vertical length A may be in a range of 0.4 m to 1.5 m. In particular, for example, the vertical length A is in a range of 0.5 m to 1.0 m. When the vertical length A satisfies such a numerical range, process costs of a process of preparing a filter for a smoking article from a lyocell material can be further reduced, and process efficiency can be further increased.
In particular, an upper limit of the vertical length A may be 1.4 m or less, 1.3 m or less, 1.2 m or less, 1.1 m or less, 1.0 m or less, 0.9 m or less, 0.8 m or less, 0.7 m or less, 0.6 m or less, or 0.5 m or less. A lower limit of the vertical length A may be 0.5 m or more, 0.6 m or more, 0.7 m or more, 0.8 m or more, 0.9 m or more, 1.0 m or more, 1.1 m or more, 1.2 m or more, 1.3 m or more, or 1.4 m or more.
As shown in FIG. 1, the vertical length A may be a vertical length of the lyocell material when the lyocell material is viewed vertically from above.
In each exemplary lyocell material, a horizontal length of the lyocell material may be in a range of 0.4 m to 1.5 m. In particular, for example, the horizontal length is in a range of 0.5 m to 1.0 m. When the horizontal length satisfies such a numerical range, process costs of a process of preparing a filter for a smoking article from a lyocell material can be further reduced, and process efficiency can be further increased.
In particular, an upper limit of the horizontal length may be 1.4 m or less, 1.3 m or less, 1.2 m or less, 1.1 m or less, 1.0 m or less, 0.9 m or less, 0.8 m or less, 0.7 m or less, 0.6 m or less, or 0.5 m or less. A lower limit of the horizontal length may be 0.5 m or more, 0.6 m or more, 0.7 m or more, 0.8 m or more, 0.9 m or more, 1.0 m or more, 1.1 m or more, 1.2 m or more, 1.3 m or more, or 1.4 m or more.
The horizontal length may be a horizontal length of the lyocell material when the lyocell material is viewed vertically from above.
In each exemplary lyocell material, the horizontal length and the vertical length A may be equal to each other. Alternatively, the horizontal length and the vertical length A may be different from each other. The horizontal length and the vertical length A may be determined in consideration of a post-process, for example, a process of preparing a filter for a smoking article.
In each exemplary lyocell material, the number of turning points may be 3 to 30 ea. In particular, for example, the number of turning points is 5 to 28 ea. When the number of turning points satisfies such a numerical range, process costs of a process of preparing a filter for a smoking article from a lyocell material can be further reduced, and process efficiency can be further increased.
In each exemplary lyocell material, the number of turning points may be the total number of times at which a stacking direction of lyocell multifilaments is reversed. Since the stacking direction is reversed, an upper side (a side observed from above) of the lyocell material is turned. Referring to FIG. 1, it may be confirmed that the upper side (that is, the side observed from above) of the lyocell material is changed before and after the turning point.

[Multi-lobal cross section]

One or more of lyocell monofilaments included in a lyocell material of the present application may have a multi-lobal cross section. The term "multi-lobal" may mean that a shape of an outline of a cross section is not circular, and the term "cross section" may be a cross section obtained by cutting a lyocell monofilament in a direction virtually or actually perpendicular to a longitudinal direction of a filament.
An outline of the multi-lobal cross section may touch each of a virtual first circle and a virtual second circle. In addition, the virtual second circle may be depicted inside the virtual first circle, and/or the virtual second circle may be placed inside the virtual first circle. The "virtual first circle" may also be referred to as a "virtual circumscribed circle" and/or a "circumscribed circle", and/or the "virtual second circle" may also be referred to as a "virtual inscribed circle" and/or an "inscribed circle".
The virtual first circle may be a circle with the smallest area value among circles drawn to completely encompass one cross section of a monofilament. The virtual second circle may be a circle with the largest area value among circles drawn inside a cross section of a monofilament.
When a circumscribed circle encompassing a cross section of a monofilament may be drawn, the virtual first circle may be the circumscribed circle. When an inscribed circle may be drawn inside a cross section of a monofilament, the virtual second circle may be the inscribed circle.
The multi-lobal cross section may have a shape including a plurality of protrusions and may be, for example, a Y-shaped cross section including three protrusions. It may be understood that the plurality of protrusions are formed as an integral type with the virtual second circle as a central portion and have a shape of which an end touches the virtual first circle. The terms described herein have the same meanings as described above.
A modified ratio of a monofilament may be defined by Equation 1 below. $Modified ratio = r 1 / r 2$
Here, r1 is a radius of the virtual first circle, and r2 is a radius of the virtual second circle.
For example, the radius of the virtual first circle may be in a range of 4 µm to 40 µm, the radius of the virtual second circle may be in a range of 2 µm to 14 µm, and the modified ratio may be in a range of 1.01 to 10.
In addition, a space occupancy ratio of a monofilament may be defined by Equation 2. $Space occupancy ratio = (S 1 / S 2) \times 100 (%)$
Here, S1 is an area of the virtual first circle, and S2 is a cross-sectional area of a monofilament included in a lyocell fiber.
For example, a space occupancy ratio of a monofilament having a multi-lobal cross section may be in a range of about 120 % to about 600 %.
In some embodiments, in the lyocell material, the lyocell multifilament may include one or more monofilaments, and one or more of the monofilaments may have a multi-lobal cross section.
In some embodiments, in the lyocell material, the lyocell multifilament may include one or more monofilaments, and the monofilaments may all have a multi-lobal cross section.

[Fineness]

A lyocell material of the present application may include a lyocell multifilament, and the lyocell multifilament may have a fineness suitable for preparing a filter for a smoking article and securing a function thereof.
For example, a single fineness of a monofilament constituting the lyocell multifilament may be in a range of 1.11 to 8.89 dtex (1.0 to 8.0 denier). In this case, a single fineness of a lyocell multifilament refers to a fineness of one monofilament separated from the lyocell multifilament before crimps are imparted.
In particular, the single fineness of the lyocell multifilament may be, for example, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 dtex (4.5 denier) or less, 4.44 dtex (4.0 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, 2.22 dtex (2.0 denier) or less, or 1.67 dtex (1.5 denier) or less. A lower limit of the single fineness of the lyocell multifilament may be, for example, 1.67 dtex (1.5 denier) or more, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, 7.78 dtex (7.0 denier) or more, or 8.33 dtex (7.5 denier) or more. Satisfying the above range may be more advantageous in securing stable physical properties (for example, implementing hardness or suction resistance) and processability of a filter for a smoking article.
For example, the lyocell material may have a total fineness of 1,667 tex to 6,111 tex (15,000 denier to 55,000 denier). For example, a lower limit of the total fineness may be 1,778 tex (16,000 denier) or more, 1,833 tex (16,500 denier) or more, 1,889 tex (17,000 denier) or more, 1,944 tex (17,500 denier) or more, 2,000 tex (18,000 denier) or more, 2,056 tex (18,500 denier) or more, 2,111 tex (19,000 denier) or more, 2,167 tex (19,500 denier) or more, 2,222 tex (20,000 denier) or more, 2,278 tex (20,500 denier) or more, 2,333 tex (21,000 denier) or more, 2,389 tex (21,500 denier) or more, 2,444 tex (22,000 denier) or more, 2,500 tex (22,500 denier) or more, 2,556 tex (23,000 denier) or more, 2,611 tex (23,500 denier) or more, 2,667 tex (24,000 denier) or more, 2,722 tex (24,500 denier) or more, 2,778 tex (25,000 denier) or more, 2,833 tex (25,500 denier) or more, 2,889 tex (26,000 denier) or more, 2,944 tex (26,500 denier) or more, 3,000 tex (27,000 denier) or more, 3,056 tex (27,500 denier) or more, 3,111 tex (28,000 denier) or more, 3,167 tex (28,500 denier) or more, 3,222 tex (29,000 denier) or more, 3,287 tex (29,500 denier) or more, 3,333 tex (30,000 denier) or more, 3,389 tex (30,500 denier) or more, 3,444 tex (31,000 denier) or more, 3,500 tex (31,500 denier) or more, 3,556 tex (32,000 denier) or more, 3,611 tex (32,500 denier) or more, 3,667 tex (33,000 denier) or more, 3,722 tex (33,500 denier) or more, 3,778 tex (34,000 denier) or more, 3,833 tex (34,500 denier) or more, 3,889 tex (35,000 denier) or more, 3,944 tex (35,500 denier) or more, 4,000 tex (36,000 denier) or more, 4,056 tex (36,500 denier) or more, 4,111 tex (37,000 denier) or more, 4,167 tex (37,500 denier) or more, 4,222 tex (38,000 denier) or more, 4,278 tex (38,500 denier) or more, 4,333 tex (39,000 denier) or more, 4,389 tex (39,500 denier) or more, 4,444 tex (40,000 denier) or more, 4,500 tex (40,500 denier) or more, 4,556 tex (41,000 denier) or more, 4,611 tex (41,500 denier) or more, 4,667 tex (42,000 denier) or more, 4,722 tex (42,500 denier) or more, 4,778 tex (43,000 denier) or more, 4,833 tex (43,500 denier) or more, 4,889 tex (44,000 denier) or more, 4,944 tex (44,500 denier) or more, 5,000 tex (45,000 denier) or more, 5,056 tex (45,500 denier) or more, 5,111 tex (46,000 denier) or more, 5,167 tex (46,500 denier) or more, 5,222 tex (47,000 denier) or more, 5,278 tex (47,500 denier) or more, 5,333 tex (48,000 denier) or more, 5,389 tex (48,500 denier) or more, 5,444 tex (49,000 denier) or more, 5,500 tex (49,500 denier) or more, 5,556 tex (50,000 denier) or more, 5,611 tex (50,500 denier) or more, 5,667 tex (51,000denier) or more, 5,722 tex (51,500 denier) or more, 5,778 tex (52,000 denier) or more, 5,833 tex (52,500 denier) or more, 5,889 tex (53,000 denier) or more, 5,944 tex (53,500 denier) or more, 6,000 tex (54,000 denier) or more, or 6,056 tex (54,500 denier) or more. An upper limit of the total fineness may be, for example, 6,056 tex (54,500 denier) or less, 6,000 tex (54,000 denier) or less, 5,944 tex (53,500 denier) or less, 5,889 tex (53,000 denier) or less, 5,833 tex (52,500 denier) or less, 5,778 tex (52,000 denier) or less, 5,722 tex (51,500 denier) or less, 5,667 tex (51,000 denier) or less, 5,611 tex (50,500 denier) or less, 5,556 tex (50,000 denier) or less, 5,500 tex (49,500 denier) or less, 5,444 tex (49,000 denier) or less, 5,389 tex (48,500 denier) or less, 5,333 tex (48,000 denier) or less, 5,278 tex (47,500 denier) or less, 5,222 tex (47,000 denier) or less, 5,167 tex (46,500 denier) or less, 5,111 tex (46,000 denier) or less, 5,056 tex (45,500 denier) or less, 5,000 tex (45,000 denier) or less, 4,944 tex (44,500 denier) or less, 4,889 tex (44,000 denier) or less, 4,833 tex (43,500 denier) or less, 4,778 tex (43,000 denier) or less, 4,722 tex (42,500 denier) or less, 4,667 tex (42,000 denier) or less, 4,611 tex (41,500 denier) or less, 4,556 tex (41,000 denier) or less, 4,500 tex (40,500 denier) or less, 4,444 tex (40,000 denier) or less, 4,389 tex (39,500 denier) or less, 4,333 tex (39,000 denier) or less, 4,278 tex (38,500 denier) or less, 4,222 tex (38,000 denier) or less, 4,167 tex (37,500 denier) or less, 4,111 tex (37,000 denier) or less, 4,056 tex (36,500 denier) or less, 4,000 tex (36,000 denier) or less, 3,944 tex (35,500 denier) or less, 3,889 tex (35,000 denier) or less, 3,833 tex (34,500 denier) or less, 3,778 tex (34,000 denier) or less, 3,722 tex (33,500 denier) or less, 3,667 tex (33,000 denier) or less, 3,611 tex (32,500 denier) or less, 3,556 tex (32,000 denier) or less, 3,500 tex (31,500 denier) or less, 3,444 tex (31,000 denier) or less, 3,389 tex (30,500 denier) or less, 3,333 tex (30,000 denier) or less, 3,278 tex (29,500 denier) or less, 3,222 tex (29,000 denier) or less, 3,167 tex (28,500 denier) or less, 3,111 tex (28,000 denier) or less, 3,056 tex (27,500 denier) or less, 3,000 tex (27,000 denier) or less, 2,944 tex (26,500 denier) or less, 2,889 tex (26,000 denier) or less, 2,833 tex (25,500 denier) or less, 2,778 tex (25,000 denier) or less, 2,722 tex (24,500 denier) or less, 2,667 tex (24,000 denier) or less, 2,611 tex (23,500 denier) or less, 2,556 tex (23,000 denier) or less, 2,500 tex (22,500 denier) or less, 2,444 tex (22,000 denier) or less, 2,389 tex (21,500 denier) or less, 2,333 tex (21,000 denier) or less, 2,278 tex (20,500 denier) or less, 2,222 tex (20,000 denier) or less, 2,167 tex (19,500 denier) or less, 2,111 tex (19,000 denier) or less, 2,056 tex (18,500 denier) or less, 2,000 tex (18,000 denier) or less, 1,944 tex (17,500 denier) or less, 1,889 tex (17,000 denier) or less, 1,833 tex (16,500 denier) or less, 1,778 tex (16,000 denier) or less, or 1,722 tex (15,500 denier) or less. When the total fineness is within the above range, the preparation processability of a filter for a smoking article can be further enhanced as a continuous process without cutting. When an amount of tow filling filter wrapping paper during preparation of a filter for a smoking article is not too small nor too large, it can be easier to secure sufficient filter physical properties (for example, hardness or suction resistance).
A method of measuring a fineness is not particularly limited, but for example, a lyocell material to be measured, for example, a 2 m sample of lyocell tow, is taken, left, and stabilized in a room with a constant temperature and humidity at a temperature of 20 °C and a humidity of 65 % for 24 hours. One end of the stabilized lyocell tow is fixed, and a 2 kg weight is attached to the other end thereof. The tow stretched due to a load thereof is maintained (stabilized) for 5 seconds and then cut into 90 cm length to obtain a sample and measure a weight of the sample (total fineness). A fineness is converted to a denier scale by calculating a measured weight×10,000 according to a denier conversion method. A single fineness is calculated by dividing the total fineness of the sample by the number of strands of monofilaments in the sample.
A total fineness of the lyocell multifilament may be determined according to the single fineness of the monofilament and the number of crimps. In the present application, a single fineness and the number of crimps may be controlled, and the total fineness of a lyocell material (for example, lyocell tow) suitable for preparing a filter for a smoking article and securing a function thereof may be secured.

[Number of crimps]

In an example, a lyocell multifilament may have 3.94 to 23.62 crimps per centimeter (10 to 60 crimps per inch). For example, the number of crimps may be 5.91 ea/cm (15 ea/inch) or more, 7.87 ea/cm (20 ea/inch) or more, 9.84 ea/cm (25 ea/inch) or more, 11.81 ea/cm (30 ea/inch) or more, 13.78 ea/cm (35 ea/inch) or more, 15.75 ea/cm (40 ea/inch) or more, or 17.72 ea/cm (45 ea/inch) or more, and an upper limit of the number of crimps may be, for example, 21.65 ea/cm (55 ea/inch) or less, 19.69 ea/cm (50 ea/inch) or less, 17.72 ea/cm (45 ea/inch) or less, 15.75 ea/cm (40 ea/inch) or less, 13.78 ea/cm (35 ea/inch) or less, 11.81 ea/cm (30 ea/inch) or less, or 9.84 ea/cm (25 ea/inch) or less. The number of crimps and the uniformity thereof may be controlled through pressure and temperature conditions or the like related to crimping which will be described below.
Although not particularly limited, the number of crimps may be measured by using, for example, a single fiber property evaluation device (for example, Favimat). In particular, a sample of a prepared lyocell material (for example, lyocell tow) may be left and stabilized for 24 hours under conditions of a temperature of 20±2 °C and a humidity of 65±4 %. A specimen may be taken from the stabilized sample such that the crimp is not damaged. The specimen may include some or all of lyocell multifilaments imparted with crimps. The taken specimen may be mounted on a dedicated jig with a length (gauge length) of 10 mm to 30 mm. An initial load during measurement may be 0.05 g/de, and crimp sensitivity may be 0.01 mm. The number of crimps may be measured under the above-described conditions (that is, a temperature of 20±2 °C and a humidity of 65±4 %).
Although not particularly limited, a lyocell material prepared to satisfy the single fineness, the total fineness, and/or the number of crimps described above may be used in a smoking article.

[Binder]

In some embodiments, the lyocell material may further include a binder. The binder may be present, for example, on a surface of the lyocell multifilament or between the lyocell multifilaments and/or between the monofilaments. The binder may further increase the hardness of a filter for a smoking article, thereby preventing problems such as filter jamming during a process of preparing a filter or a process of preparing a smoking article (for example, a tobacco).
Types of available binders are not particularly limited, and any known binder may be used at a level that does not impede the purpose of the disclosure. For example, a binder capable of providing sufficient compatibility with an emulsion used in the present application, improving the hardness of a filter, and providing excellent bonding strength may be used.
For example, the binder may include a polyester-based binder, a cellulose-based binder, and/or a vinyl-based binder.
Although not particularly limited, as the polyester-based binder, a polyester binder including at least one selected from the group consisting of alkylene, arylene, and heteroarylene, having 5 to 12 carbon atoms may be used.
Examples of the cellulose-based binder may include hydroxypropyl methyl cellulose (HPMC), ethyl cellulose (EC), methyl cellulose (MC), and/or carboxymethyl cellulose (CMC), but one or more embodiments are not limited thereto.
In some embodiments, the cellulose-based binder is selected from the group consisting of HPMC, EC, MC, CMC, and a combination thereof.
Examples of the vinyl-based binder may include polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and/or ethylene vinyl acetate (EVAc), but one or more embodiments are not limited thereto.
A method of applying the binder to a lyocell material (for example, coating) will be described below.

[Emulsion]

The lyocell material may include a lyocell multifilament, and an emulsion applied onto the lyocell multifilament. The emulsion may include: (a) an esterified product of a fatty acid having 16 or more carbon atoms and aliphatic monohydric alcohol; and (b) an esterified product of sorbitan and a fatty acid having 16 or more carbon atoms. The emulsion may be applied onto some or all of monofilaments or multifilaments constituting the lyocell material. In addition, the emulsion may permeate between filaments.
The emulsion including at least components (a) and (b) may have hydrophobicity. As a result, the lyocell material treated with the emulsion may have excellent spreading properties.
In some embodiments, the lyocell material may include a certain content of the emulsion. In this case, the content of the emulsion may refer to an oil pick up ratio (OPU) (wt%) which will be described below. For example, the lyocell material may include the emulsion in a content of 0.1 wt% or more with respect to 100 wt% of the total weight of the lyocell material. In particular, the content of the emulsion may be 0.5 wt% or more, 1.0 wt% or more, 1.5 wt% or more, 2.0 wt% or more, 2.5 wt% or more, or 3.0 wt% or more, or In particular 3.5 wt% or more, 4.0 wt% or more, 4.2 wt% or more, 4.5 wt% or more, 5.0 wt% or more, 5.5 wt% or more, 6.0 wt% or more, 6.5 wt% or more, 7.0 wt% or more, 7.5 wt% or more, 8.0 wt% or more, 8.5 wt% or more, 9.0 wt% or more, or 9.5 wt% or more. An upper limit of the content of the emulsion may be, for example, 20.0 wt% or less, 18.0 wt% or less, 17.0 wt% or less, 16.0 wt% or less, 15.0 wt% or less, 14.5 wt% or less, 14.0 wt% or less, 13.5 wt% or less, 13.0 wt% or less, 12.5 wt% or less, 12.0 wt% or less, 11.5 wt% or less, 11.0 wt% or less, 10.5 wt% or less, 10 wt% or less, 9.5 wt% or less, 9.0 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.8 wt% or less, or 7.6 wt% or less.
As a method of measuring the content (OPU) of the emulsion, for example, an extrusion method may be used. For example, a sample (for example, in a content of 2 g to 5 g or in particular about 2.5 g) is taken (in this case, a weight of the taken sample is referred to as a sample weight), and the sample is put into a syringe-shaped container. A material of the container is not particularly limited, but may be a stainless steel (SUS) material. Next, a solvent (for example, methanol) is put into the container into which the sample is put (an amount of the put solvent may be 10 ml or less (for example, about 8 ml)). When the solvent is added to the sample, a dropping method may be used, and a dropping speed may be uniformly adjusted. As described above, the solvent put into the container is allowed to drop on a plate from one end of the syringe-shaped container. In this case, the plate is pre-weighed (a measured weight is referred to as plate weight A), and the plate is installed such that the solvent dropped on the plate is removed away (that is, evaporated) at a temperature of 120 °C to 130 °C (for example, 125 °C). The solvent addition and solvent dropping are performed three times, and pressure (for example, 98 kgf/cm² (10 kgf/cm²) or less, preferably 49 N/cm² (5 kgf/cm²) or less, or further preferably 18 N/cm² (2 kgf/cm²) to 39 N/cm² (4 kgf/cm²)) is applied to the sample by using a syringe-shaped container to press the sample once. Thus, the solvent and emulsion present in the sample are sufficiently extruded. The sample is squeezed out by applying pressure until the solvent does not come out any more. Afterwards, the plate is stored in a desiccator for 5 minutes to 10 minutes, and a weight (plate weight B) of the plate containing the sample is measured. Then, a content of the emulsion is calculated according to the following formula. Formula Content of emulsion by extrusion (OPU, % or wt%) = {(plate weight B-plate weight A)/(sample weight)} × 100
In addition, a lyocell material that is used as a reference for the content of the emulsion may be a lyocell multifilament treated with an emulsion. For example, the lyocell material may be a lyocell multifilament to which primary emulsion treatment (to be described below) has been applied, a lyocell multifilament to which primary emulsion treatment and secondary emulsion treatment (to be described below) have been applied, or a lyocell multifilament treated with the above-described emulsion and also treated with a binder to be described below. In addition, the lyocell multifilament treated with the emulsion and/or the binder may be imparted with crimps.
Regarding the emulsion of the present application, component (a) may be a compound that can function as a type of lubricant or oil and may be a component that is harmless to the human body enough to be used in food. Component (a) can further provide lubricity to fibers put into a crimper. When the lubricity is sufficient, lyocells does not clump together and can escape the crimper better. In consideration of such functions, a content of component (a) may be controlled as described below.
Regarding component (a), types of fatty acids having 16 or more carbon atoms forming the esterified product are not particularly limited. Fatty acids having 16 or more carbon atoms may be used as long as the fatty acids may provide esterified products that are harmless to the human body enough to be used in food.
For example, saturated fatty acids and/or unsaturated fatty acids may be used as fatty acids having one or more 16 carbon atoms.
Examples of the saturated fatty acids may include a palmitic acid (hexadecanoic acid, CH₃(CH₂)₁₄COOH), a margaric acid (heptadecanoic acid, CH₃(CH₂)₁₅COOH), a stearic acid (octadecanoic acid, CH₃(CH₂)₁₆COOH), a nonadecylic acid (nonadecanoic acid, CH₃(CH₂)₁₇COOH), or an arachidic acid (eicosanoic acid, CH₃(CH₂)₁₈COOH). However, types of available saturated fatty acids are not limited thereto.
Examples of the unsaturated fatty acids may include a palmitoleic acid (CH₃(CH₂)₅CH=CH(CH₂)₇COOH), an oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH), a linoleic acid (C₁₈H₃₂O₂), or an arachidonic acid (C₂₀H₃₂O₂). However, types of available unsaturated fatty acids are not limited thereto.
An upper limit of a carbon number of the fatty acid having 16 or more carbon atoms is not particularly limited, but may be, for example, 40 or less, preferably 36 or less, further preferably 32 or less, further preferably 28 or less, further preferably 24 or less, or further preferably 20 or less.
In some embodiments, the fatty acid is selected from the group consisting of a palmitic acid, a margaric acid, a stearic acid, a nonadecylic acid, an arachidic acid, a palmitoleic acid, an oleic acid, a linoleic acid, and an arachidonic acid.
Regarding component (a), types of aliphatic monohydric alcohols forming the ester compound are also not particularly limited. Aliphatic monohydric alcohols may be used as long as the aliphatic monohydric alcohols may provide esterified products that are harmless to the human body enough to be used in foods.
For example, the aliphatic monohydric alcohol may be saturated aliphatic alcohol or unsaturated aliphatic alcohol, which may have a linear or branched form.
In an example, a carbon number of the aliphatic monohydric alcohol may be in a range of 1 to 40. In particular, the carbon number of the aliphatic monohydric alcohol may be, for example, 4 or more, preferably 8 or more, further preferably 12 or more, further preferably 16 or more, or further preferably 20 or more.
Examples of the aliphatic monohydric alcohol may include methanol, ethanol, butanol, lauryl alcohol, isotridecanol, or stearyl alcohol, but one or more embodiments are not limited thereto.
In some embodiments, the aliphatic monohydric alcohol is selected from the group consisting of methanol, ethanol, butanol, lauryl alcohol, isotridecanol, and stearyl alcohol.
In some embodiments, an esterified product of isotridecanol and a stearic acid (for example, isotridecyl stearate) may be used as component (a). However, types of available component (a) are not limited thereto.
As will be described below, a content of component (a) included in the emulsion may be adjusted in consideration of the function of the emulsion or the function of component (a).
Component (b), that is, an esterified product of sorbitan and a fatty acid having 16 or more carbon atoms, is a compound that can function as a type of emulsifier and may be a component harmless to the human body enough to be used in food.
Since component (b) has both hydrophilicity and hydrophobicity due to polyhydric alcohol (that is, sorbitan), component (b) enables component (a), which provides lubricity to the fiber, to be well dispersed in water which will be described below. In addition, components (a) and (b) used together not only may increase the dispersibility of the emulsion as described above, but also may lower a melting point, thereby ensuring the use/handling and stability of the emulsion. In consideration of such functions, a content of component (b) may be controlled as described below.
Regarding component (b), types of fatty acids having 16 or more carbon atoms forming the esterified product are not particularly limited. Fatty acids having 16 or more carbon atoms may be used as long as the fatty acids may provide esterified products that are harmless to the human body enough to be used in food.
For example, saturated fatty acids and/or unsaturated fatty acids may be used as fatty acids having one or more 16 carbon atoms.
Examples of the saturated fatty acids may include a palmitic acid (hexadecanoic acid, CH₃(CH₂)₁₄COOH), a margaric acid (heptadecanoic acid, CH₃(CH₂)₁₅COOH), a stearic acid (octadecanoic acid, CH₃(CH₂)₁₆COOH), a nonadecylic acid (nonadecanoic acid, CH₃(CH₂)₁₇COOH), or an arachidic acid (eicosanoic acid, CH₃(CH₂)₁₈COOH). However, types of available saturated fatty acids are not limited thereto.
Examples of the unsaturated fatty acids may include a palmitoleic acid (CH₃(CH₂)₅CH=CH(CH₂)₇COOH), an oleic acid (CH₃(CH₂)₇CH=CH(CH₂)₇COOH), a linoleic acid (C₁₈H₃₂O₂), or an arachidonic acid (C₂₀H₃₂O₂). However, types of available unsaturated fatty acids are not limited thereto.
An upper limit of a carbon number of the fatty acid having 16 or more carbon atoms is not particularly limited, but may be, for example, 40 or less, preferably 36 or less, further preferably 32 or less, further preferably 28 or less, further preferably 24 or less, or further preferably 20 or less.
In some embodiments, the fatty acid is selected from the group consisting of a palmitic acid, a margaric acid, a stearic acid, a nonadecylic acid, an arachidic acid, a palmitoleic acid, an oleic acid, a linoleic acid, and an arachidonic acid
In In some embodiments, an esterified product of sorbitan and an oleic acid (for example, sorbitan monooleate) may be used as component (b). However, types of available component (b) are not limited thereto.
A content of component (b) may be adjusted in consideration of the function of component (b) and the function of the emulsion as described above.
For example, the emulsion may include (b) an esterified product of sorbitan and a fatty acid having 16 or more carbon atoms in a content of 20 parts by weight to 60 parts by weight with respect to 100 parts by weight of (a) an esterified product of a fatty acid having 16 or more carbon atoms and aliphatic monohydric alcohol.
In particular, the emulsion of the present application may include component (b) in a content of 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, 45 parts by weight or more, or 50 parts by weight or more with respect to 100 parts by weight of component (a). An upper limit of the content of component (b) with respect to 100 parts by weight of component (a) may be, for example, 55 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, or 25 parts by weight or less. When the above range of the content is satisfied, a surface of a lyocell multifilament or lyocell tow treated with an emulsion can have more hydrophobicity.
For example, the emulsion may include (a) the esterified product of the fatty acid having 16 or more carbon atoms and aliphatic monohydric alcohol in a content of 40 wt% to 80 wt% with respect to 100 wt% of the total weight of the emulsion. In particular, the content of component (a) may be 45 wt% or more, 50 wt% or more, 55 wt% or more, 60 wt% or more, or 65 wt% or more, 70 wt% or more, or 75 wt% or more with respect to 100 wt% of the total weight of the emulsion. An upper limit of the content of component (a) may be, for example, 75 wt% or less, 70 wt% or less, 65 wt% or less, 60 wt% or less, 55 wt% or less, 50 wt% or less, or 45 wt% or less.
For example, the emulsion may include an excess amount of component (a).
For example, the emulsion may include (b) the esterified product of sorbitan and the fatty acid having 16 or more carbon atoms in a content of 15 wt% to 55 wt% with respect to 100 wt% of the total weight of the emulsion. In particular, the content of component (b) may be 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, or 50 wt% or more with respect to 100 wt% of the total weight of the emulsion. An upper limit of the content of component (b) may be, for example, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, or 25 wt% or less.
For example, the emulsion may further include water. A small amount of water may assist in emulsifying. As used herein, the terms "treated with emulsion" and "emulsified" may be used interchangeably.
A content of water is not particularly limited, but water may be included in the remaining content excluding the total content of components (a) and (b) with respect to 100 wt% of the total weight of the emulsion. The content of water in the emulsion (that is, the remaining content excluding the total content of the remaining components excluding water) may be, for example, 10 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, or 1 wt% or less. A lower limit of the content of water may be, for example, 0 wt% or more, 0.1 wt% or more, 0.5 wt% or more, or 1 wt% or more.

[Method of preparing lyocell material]

The present application relates to a method of preparing a lyocell material. Through the method, a lyocell material may be prepared and used in a smoking article.
In particular, the method of preparing a lyocell material includes: a lyocell dope spinning; coagulation and multifilament obtainment; washing; emulsion treatment; and crimp imparting. In addition, the method of preparing a lyocell material may further include: binder treatment; and other operations.
The emulsion treatment may be performed before the crimp imparting, after the crimp imparting, or before and after the crimp imparting.
Emulsion treatment may each independently be performed, for example, by spraying an emulsion with the above-described composition onto a lyocell multifilament or immersing the lyocell multifilament in the emulsion. As described above, the emulsion treatment may be performed such that a content (for example, OPU (wt%)) of an emulsion in the lyocell material satisfies a certain range.
The crimp imparting may be performed, for example, by applying steam and/or pressure to the lyocell multifilament.
The method of preparing a lyocell material according to a specific embodiment of the present application, including the emulsion treatment and the crimp imparting, will be described in more detail below. The method of the present application may be performed by including one or more of operations described below.

<Lyocell dope spinning (a)>

A corresponding operation may be an operation of spinning a lyocell spinning dope including lyocell cellulose and/or lyocell cellulose pulp and N-methylmorpholine-N-oxide (NMMO).
Commercialized cellulose acetate filters are pointed out as the major cause of microplastics. However, since an amine oxide-based solvent used in preparing lyocell fibers is recyclable and biodegradable even when disposed of, lyocell materials do not generate any pollutants during a production process thereof. Furthermore, since lyocell tow is biodegraded and removed within a relatively short period of time, the lyocell is a more environmentally friendly material than cellulose acetate.
In an example, a content of cellulose in the spinning dope may be in a range of 5 wt% to 15 wt% with respect to 100 wt% of the total weight of the spinning dope. When the content of cellulose is too low, it may be difficult to implement the properties of a lyocell fiber, and when the content exceeds the above range, it may be difficult to dissolve cellulose in a solvent. In consideration of the difficulties, the content of cellulose in the spinning dope may be 6 wt% or more, preferably 7 wt% or more, further preferably 8 wt% or more, further preferably 9 wt% or more, or further preferably 10 wt% or more, with respect to 100 wt% of the total weight of the spinning dope, and an upper limit thereof may be, for example, 14 wt% or less, preferably 13 wt% or less, further preferably 12 wt% or less, further preferably 11 wt% or less, further preferably 10 wt% or less, or further preferably 9 wt% or less, with respect to 100 wt% of the total weight of the spinning dope.
In an example, the spinning dope may include an aqueous solution of NMMO. The aqueous solution may include, for example, NMMO in a content of 80 parts by weight to 95 parts by weight and water in a content of 5 parts by weight to 20 parts by weight in consideration of a degree of dissolution of cellulose and a process temperature.
In an example, the cellulose and/or the cellulose pulp may include alpha-cellulose in a content of 85 wt% to 97 wt% with respect to 100 wt% of the total weight of the cellulose and/or the cellulose pulp.
In an example, the cellulose and/or the cellulose pulp may include hemicellulose in a content of 1 wt% to 15 wt% with respect to 100 wt% of the total weight of the cellulose and/or the cellulose pulp. By adjusting the content of the hemicellulose within the above range, the stable physical properties (for example, hardness or suction resistance implementation) and processability of a lyocell material may be more easily secured.
In addition, in some embodiments, a degree of polymerization (DPw) of the cellulose may be in a range of 600 to 1,700. In some embodiments, the DPw refers to the number of repeating units and/or monomers of the cellulose, alpha-cellulose, and/or hemicellulose in the cellulose pulp.
In the spinning, a shape of a spinneret for discharging the spinning dope is not particularly limited. For example, a donut-shaped spinneret may be used.
A nozzle temperature of the spinneret, In particular, a spinning temperature thereof, may be appropriately selected by a person skilled in the art. Considering that the viscosity of the spinning dope may vary according to the spinning temperature, and thus discharging may not be performed smoothly, the spinning temperature may be, for example, in a range of 100 °C to 120 °C or 100 °C to 110 °C.
In an example, the spinning of the spinning dope may be performed under spinning conditions in which a fineness of a filament is controlled to be in a range of 1.67 dtex to 8.894 dtex (1.5 denier to 8.0 denier). For example, one or more spinning conditions of a discharge amount and a spinning speed of the spinning dope may be appropriately controlled so that a single fineness of a filament included in a lyocell material may satisfy a range of 1.67 dtex to 8.89 dtex (1.5 denier to 8.0 denier). In this case, a single fineness of a filament may refer to a fineness of a single monofilament separated from a multifilament.
In particular, the single fineness of the filament may be, for example, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 dtex (4.5 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, or 2.22 dtex (2.0 denier) or less. A lower limit of the single fineness of the filament may be, for example, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, or 7.78 dtex (7.0 denier) or more. Satisfying the above range may be more advantageous in implementing stable suction resistance and securing processability of a filter for a smoking article.
The spinning dope discharged through the spinneret may undergo the coagulation which will be described below.

<Coagulation and multifilament obtainment (b)>

In a corresponding operation, the spun lyocell spinning dope may be coagulated, and a lyocell multifilament may be obtained.
For the coagulation, a method in which the spun dope comes into contact with air and/or a coagulating solution may be used.
In an example, the coagulation may include: primary coagulation of supplying cooling air to the spun lyocell dope; and secondary coagulation of adding a primarily coagulated spun dope to a coagulating solution to coagulate the spun dope.
According to such a coagulation method, the lyocell dope discharged through the spinneret may be primarily coagulated in a space (air gap section) between the spinneret and a coagulation tank. For example, cooling air may be supplied to the air gap section from an air cooling part positioned inside the spinneret in a direction from the inside to the outside of the spinneret. In addition, the primary coagulation may be achieved through a known so-called air quenching method or means in the related field.
In an example, an upper limit of a temperature of the cooling air used for the primary coagulation may be 15 °C or less. In particular, the cooling air may be air with a temperature of 14 °C or less, preferably 13 °C or less, further preferably 12 °C or less, further preferably 11 °C or less, or further preferably 10 °C or less. When the above temperature is exceeded, the coagulation of the spun dope by air may not be sufficient, and spinning-related processability may not be good.
A lower limit of the temperature of the cooling air may be determined in consideration of spinning processability and/or cross-sectional uniformity of a filament. For example, when the temperature of the cooling air is less than 4 °C, a surface of the spinneret may cool, a surface of the filament may become non-uniform, and the spinning processability may also deteriorate. In consideration of this, the cooling air may have a temperature of 5 °C or more, preferably 6 °C or more, further preferably 7 °C or more, further preferably 8 °C or more, or further preferably 9 °C or more.
A degree by which the cooling air is supplied may be adjusted in consideration of sufficient coagulation, spinning processability, and an influence on the physical properties of the filament. For example, the cooling air may be supplied to the discharged spinning dope at an air flow rate of 70 Nm³/h to 400 Nm³/h per one spinneret. In particular In particular, the air flow rate may be 100 Nm³/h or more, 150 Nm³/h or more, 200 Nm³/h or more, or 250 Nm³/h or more, and an upper limit thereof may be, for example, 350 Nm³/h or less, 300 Nm³/h or less, 250 Nm³/h or less, 200 Nm³/h or less, or 150 Nm³/h or less.
After the primary coagulation as described above, the cooled spinning dope may be supplied to a coagulation tank or bath containing a coagulating solution (secondary coagulation). For proper coagulation, a temperature of the coagulating solution may be, for example, 30 °C or less or 25 °C or less. The temperature of the coagulating solution may be 10 °C or more, 15 °C or more, or 20 °C or more. When the above temperature is maintained, a coagulation speed may be appropriately maintained.
A type of a coagulating solution for the secondary coagulation as described above is not particularly limited. For example, the coagulating solution may include at least one selected from water and NMMO.
Although not particularly limited, when the coagulating solution includes water and NMMO, a content of water in the coagulating solution may be in a range of 60 wt% to 90 wt%, and a content of NMMO may be in a range of 10 wt% to 40 wt%. Alternatively, the coagulating solution may include water in a content of 70 wt% to 80 wt% and NMMO in a content of 20 wt% to 30 wt% with respect to 100 wt% of the total weight of the coagulating solution. By using sensors or the like, a concentration of the coagulating solution may be controlled to be maintained during a preparation process.

<Washing (c)>

If necessary, washing may be performed on a lyocell multifilament after the above-described coagulation and multifilament obtainment. Through such washing, NMMO and/or other impurities remaining in the filament may be removed.
A method of performing washing is not particularly limited. For example, washing may be performed by introducing a coagulated lyocell multifilament into a washing tank by using a traction roller. Alternatively or additionally, the washing may be performed by spraying a washing solution while moving to a subsequent operation by a traction roller.
Components of the washing solution are not particularly limited. For example, the washing solution may include water and optionally may further include one or more known additives.
In some embodiments, the washing solution further includes water and one or more known additives.
In addition, in consideration of reuse after washing, the washing solution may be used by adjusting a temperature thereof to 100 °C or lower.

<Emulsion treatment (d)>

If required, an operation of treating the lyocell multifilament with an emulsion may be performed. The operation may be an operation of applying an emulsion with the above-described components onto a surface of the filament. Through emulsion treatment, friction applied to the filament may be reduced, and crimps may be formed well in the crimp imparting which will be described below. When the emulsion treatment is performed twice or more as described below, the emulsion treatment may be referred to as primary emulsion treatment and secondary emulsion treatment according to the order.
Although not particularly limited, the emulsion treatment may be performed by immersing the lyocell multifilament in a bath filled with an emulsion such that the lyocell multifilament is completely immersed in the emulsion. Alternatively or additionally, the lyocell multifilament may be treated with an emulsion by spraying the emulsion while moving to a subsequent operation by a traction roller.
In order to ensure that an amount of the emulsion applied onto the lyocell multifilament is constant after the emulsion treatment as described above, a process in which rolls or the like positioned before and/or after the emulsion treatment squeeze out an emulsion of a surface of the lyocell multifilament may be additionally performed.
In an example, the emulsion treatment may be performed such that a content (OPU (wt%)) of the emulsion is 1.0 wt% or more with respect to 100 wt% of a lyocell multifilament which has been at least treated with an emulsion. In this case, the lyocell multifilament which has been at least treated with the emulsion, for example, the lyocell material, may be a lyocell multifilament to which primary emulsion treatment has been applied, a lyocell multifilament to which primary emulsion treatment and secondary emulsion treatment (see the description below) have been applied, or a lyocell multifilament to which the emulsion treatment as described above and a binder described below have been applied together. The lyocell multifilament treated with the emulsion and/or the binder as described above may be imparted with crimps.
In particular, in the lyocell multifilament which has been at least treated with the emulsion, a content of the emulsion may be 0.5 wt% or more, 1.0 wt% or more, 1.5 wt% or more, 2.0 wt% or more, 2.5 wt% or more, or 3.0 wt% or more, in particular, 3.5 wt% or more, 4.0 wt% or more, 4.2 wt% or more, 4.5 wt% or more, 5.0 wt% or more, 5.5 wt% or more, 6.0 wt% or more, 6.5 wt% or more, 7.0 wt% or more, 7.5 wt% or more, 8.0 wt% or more, 8.5 wt% or more, 9.0 wt% or more, or 9.5 wt% or more, with respect to 100 wt% of the lyocell multifilament which has been at least treated with the emulsion. An upper limit of the content of the emulsion may be, for example, 20.0 wt% or less, 18.0 wt% or less, 17.0 wt% or less, 16.0 wt% or less, 15.0 wt% or less, 14.5 wt% or less, 14.0 wt% or less, 13.5 wt% or less, 13.0 wt% or less, 12.5 wt% or less, 12.0 wt% or less, 11.5 wt% or less, 11.0 wt% or less, 10.5 wt% or less, 10 wt% or less, 9.5 wt% or less, 9.0 wt% or less, 8.5 wt% or less, 8.0 wt% or less, 7.8 wt% or less, or 7.6 wt% or less, with respect to 100 wt% of the lyocell multifilament which has been at least treated with the emulsion. In this case, the above content may refer to a dry weight after a solvent (for example, water) or liquid component that may be included in the emulsion has evaporated.
When the lyocell multifilament is treated with the emulsion with the above-described composition within the above range of the content, the hydrophilic properties of the lyocell material may be supplemented.
In some cases, the emulsion may be dried after the emulsion treatment as described above.
In a aspect of the present application, one or more of the above-described operations may be controlled such that a single fineness of a filament constituting the lyocell multifilament may be in a range of 1.67 dtex to 8.89 dtex (1.5 denier to 8.0 denier). The single fineness of the filament may refer to a fineness of a single monofilament separated from a multifilament.
In particular, the single fineness of the filament may be, for example, 8.33 dtex (7.5 denier) or less, 7.78 dtex (7.0 denier) or less, 7.22 dtex (6.5 denier) or less, 6.67 dtex (6.0 denier) or less, 6.11 dtex (5.5 denier) or less, 5.56 dtex (5.0 denier) or less, 5.00 dtex (4.5 denier) or less, 3.89 dtex (3.5 denier) or less, 3.33 dtex (3.0 denier) or less, 2.78 dtex (2.5 denier) or less, or 2.22 dtex (2.0 denier) or less. A lower limit of the single fineness of the filament may be, for example, 2.22 dtex (2.0 denier) or more, 2.78 dtex (2.5 denier) or more, 3.33 dtex (3.0 denier) or more, 3.89 dtex (3.5 denier) or more, 4.44 dtex (4.0 denier) or more, 5.00 dtex (4.5 denier) or more, 5.56 dtex (5.0 denier) or more, 6.11 dtex (5.5 denier) or more, 6.67 dtex (6.0 denier) or more, 7.22 dtex (6.5 denier) or more, or 7.78 dtex (7.0 denier) or more. Satisfying the above range may be more advantageous in implementing stable suction resistance and securing processability of a filter for a smoking article.
Although not particularly limited, an operation controlled to secure the above range of the single fineness may be the above-described spinning. Alternatively, the above-described spinning, coagulation, washing, and emulsion treatment may all be controlled to secure the above range of the single fineness.

<Crimp imparting (e)>

The crimp imparting is an operation of applying pressure to the lyocell multifilament treated with the emulsion through steam and/or a press roller to obtain a crimped multifilament, for example, crimped tow. The crimp imparting may be referred to as crimping.
Through crimping, waves are imparted to the lyocell multifilament, and fibers can have bulky properties. The crimping may be performed by using known crimp machines such as a stuffer box and/or a steam box, and available crimp machines are not particularly limited as long as the crimp machines are devices capable of applying one or more of pressures which will be described below.
In an example, the crimp imparting may be performed by first supplying steam to the lyocell multifilament to preheat and swell the lyocell multifilament, and then pressing the lyocell multifilament with a press roller to form wrinkles in the lyocell multifilament. In this case, a steam box may be used to supply steam, and the steam box may be positioned in front of the crimp machine.
In an example, the crimp imparting may be performed in such a manner that pressing of the lyocell multifilament by the press roller and applying of steam are simultaneously performed.
In an example, the crimp imparting may be performed in such a manner that steam is first supplied to the lyocell multifilament to preheat and swell the lyocell multifilament, and then pressing of the lyocell multifilament by the press roller and applying of steam are simultaneously performed.
In an example, the crimp imparting may be performed by applying steam with a pressure of 0.98 N/cm² (0.1 kgf/cm²) to 19.61 N/cm² (2.0 kgf/cm²) to the lyocell multifilament before the lyocell multifilament is put into the crimp machine (for example, the press roller).
For example, steam with a pressure of 1.96 N/cm² (0.2 kgf/cm²) or more, 2.94 N/cm² (0.3 kgf/cm²) or more, 3.92 N/cm² (0.4 kgf/cm²) or more, 4.90 N/cm² (0.5 kgf/cm²) or more, or 5.88 N/cm² (0.6 kgf/cm²) or more may be supplied by the crimp machine (for example, the steam box). In addition, steam with a pressure of 14.71 N/cm² (1.5 kgf/cm²) or less, 13.73 N/cm² (1.4 kgf/cm²) or less, 12.75 N/cm² (1.3 kgf/cm²) or less, 11.77 N/cm² (1.2 kgf/cm²) or less, 10.78 N/cm² (1.1 kgf/cm²) or less, or 9.81 N/cm² (1.0 kgf/cm²) or less may be supplied. When an amount or pressure of supplied steam is within the above range, crimps can be formed more smoothly. When an amount or pressure of supplied steam is within the above range, since the increase of the flexibility of the filament is prevented, excessive crimps cannot be imparted to the filament in the crimp machine, and thus the filament can pass more smoothly through the crimp machine.
In an example, the crimp imparting may be performed by pressing the lyocell multifilament with the press roller to form wrinkles in the lyocell multifilament. In addition, steam may not be supplied before pressing, steam may not be supplied simultaneously with pressing, or steam may not be supplied before pressing and simultaneously with pressing.
In an example, the crimp imparting may be performed by applying a pressure of 14.71 N/cm² (1.5 kgf/cm²)to 39.23 N/cm² (4.0 kgf/cm²) to the lyocell multifilament put into the crimp machine by using the press roller.
For example, a pressure of 15.69 N/cm² (1.6 kgf/cm²) or more, 16.67 N/cm² (1.7 kgf/cm²) or more, 17.65 N/cm² (1.8 kgf/cm²) or more, 18.63 N/cm² (1.9 kgf/cm²) or more, 19.61 N/cm² (2.0 kgf/cm²) or more, 20.60 N/cm² (2.1 kgf/cm²) or more, 21.58 N/cm² (2.2 kgf/cm²) or more, 22.56 N/cm² (2.3 kgf/cm²) or more, 23.54 N/cm² (2.4 kgf/cm²) or more, or 24.52 N/cm² (2.5 kgf/cm²) or more may be applied to the lyocell multifilament through the press roller. In addition, a pressure of 38.25 N/cm² (3.9 kgf/cm²) or less, 37.27 N/cm² (3.8 kgf/cm²) or less, 36.29 N/cm² (3.7 kgf/cm²) or less, 35.31 N/cm² (3.6 kgf/cm²) or less, 34.33 N/cm² (3.5 kgf/cm²) or less, 33.35 N/cm² (3.4 kgf/cm²) or less, 32.37 N/cm² (3.3 kgf/cm²) or less, 31.39 N/cm² (3.2 kgf/cm²) or less, 30.41 N/cm² (3.1 kgf/cm²) or less, 29.42 N/cm² (3.0 kgf/cm²) or less, 28.44 N/cm² (2.9 kgf/cm²) or less, 27.46 N/cm² (2.8 kgf/cm²) or less, 26.48 N/cm² (2.7 kgf/cm²) or less, 25.50 N/cm² (2.6 kgf/cm²) or less, or 24.52 N/cm² (2.5 kgf/cm²) or less may be applied through the press roller.
When the pressure of the press roller is less than the above range, the desired number of crimps may not be formed sufficiently. When the pressure of the press roller exceeds the above range, a pressing force may be too strong, and thus the filament may not be smoothly put into the crimp machine or may not pass through the crimp machine (for example, the stuffer box). Wrinkles may be formed in the lyocell multifilament by the press roller that provides the pressure.
In an example, a pressure of 0.98 N/cm² (0.1 kgf/cm²) to 19.61 N/cm² (2 kgf/cm²) may be applied to the lyocell multifilament by using an upper plate. In addition, the upper plate may apply pressure to the lyocell multifilament when the lyocell multifilament has passed between the press rollers or while the lyocell multifilament is passing between the press rollers.
For example, the pressure applied by the upper plate may be 1.96 N/cm² (0.2 kgf/cm²) or more, 2.94 N/cm² (0.3 kgf/cm²) or more, 3.92 N/cm² (0.4 kgf/cm²) or more, or 4.90 N/cm² (0.5 kgf/cm²) or more. In addition, a pressure of 14.71 N/cm² (1.5 kgf/cm²) or less, 13.73 N/cm² (1.4 kgf/cm²) or less, 12.75 N/cm² (1.3 kgf/cm²) or less, 11.77 N/cm² (1.2 kgf/cm²) or less, 10.79 N/cm² (1.1 kgf/cm²) or less, or 9.81 N/cm² (1.0 kgf/cm²) or less may be applied by the upper plate.
Furthermore, when the pressure of the upper plate, which vertically moves to impart uniform crimps after the lyocell multifilament passes between the press rollers, is less than 0.98 N/cm² (0.1 kgf/cm²), since the upper plate may not be fixed due to a pressure inside the crimp machine (for example, the stuffer box), while tow remains in the crimp machine (for example, the stuffer box) for a long time, the continuity of a process may not be maintained. When the pressure of the upper plate exceeds 19.61 N/cm² (2 kgf/cm²), since steam inside the crimp machine (for example, the stuffer box) may not be smoothly discharged, a shape of each crimps may be irregular.
In an example, in the crimp imparting, a doctor blade that applies a certain pressure to the lyocell multifilament may be applied. The doctor blade may adjust a residence time of a filament put into the crimp machine (for example, the stuffer box), thereby contributing to the control of the number of crimps. The doctor blade may be positioned, for example, on a movement path of the lyocell multifilament that is pressed by the above-described press roller and then discharged from a roller pressing point.
In an example, the crimp imparting may be performed by applying a pressure of 0.98 N/cm² (0.1 kgf/cm²) to 19.61 N/cm² (2.0 kgf/cm²) to the lyocell multifilament, which has passed between the press rollers of the crimp machine, by using the doctor blade.
For example, the pressure applied by the doctor blade may be 1.96 N/cm² (0.2 kgf/cm²) or more, 2.94 N/cm² (0.3 kgf/cm²) or more, 3.92 N/cm² (0.4 kgf/cm²) or more, or 4.90 N/cm² (0.5 kgf/cm²) or more. In addition, a pressure of 14.71 N/cm² (1.5 kgf/cm²) or less, 13.73 N/cm² (1.4 kgf/cm²) or less, 12.75 N/cm² (1.3 kgf/cm²) or less, 11.77 N/cm² (1.2 kgf/cm²) or less, 10.79 N/cm² (1.1 kgf/cm²) or less, or 9.81 N/cm² (1.0 kgf/cm²) or less may be applied by the doctor blade.
In an example, the crimp imparting may be performed at a temperature ranging from 120 °C to 250 °C. In the temperature range, the effect of stabilizing the shape of the crimp can be further enhanced, and a concentration of fat and oil inside the crimp machine (for example, the stuffer box) can be further increased, which can make it easier to form crimps. Therefore, in consideration of the above-described pressure of the steam or the like, a temperature may be appropriately controlled in a range of 130 °C or higher, 140 °C or higher, or 150°C or higher, and 200 °C or lower, 180 °C or lower, or 160 °C or lower.

<Binder treatment (f)>

In an example, the method may further include an operation of treating the lyocell multifilament, which is treated with the emulsion, with a binder, or treating the lyocell multifilament, which is obtained through the crimp imparting, with a binder.
When a filter for a smoking article is prepared by using the lyocell material (for example, lyocell tow), a binder may be additionally used. The binder may increase the hardness of a filter for a smoking article including a lyocell material, thereby preventing problems such as filter jamming during a process of preparing a filter or a process of preparing a tobacco.
A method of treating (for example, coating) the lyocell material with the binder is not particularly limited. For example, binder treatment may be performed by immersing the lyocell multifilament in a bath filled with a binder and/or a binder solution such that the lyocell multifilament is completely immersed in the binder and/or the binder solution. Alternatively or additionally, binder treatment (for example, coating) may be performed by spraying and/or injecting a binder and/or the binder solution through a nozzle.
Types and components of available binders are as described above, and thus descriptions thereof are omitted.
In an example, the binder and/or the binder solution may further include a solvent in addition to the components described above. Examples of the solvent may include water, ethanol, propylene glycol, and/or glycerin, but one or more embodiments are not limited thereto. When the binder and/or the binder solution includes a solvent, a content of the solvent may be, for example, in a range of about 20 wt% to about 80 wt% or about 40 wt% to about 60 wt% with respect to 100 wt% of the total weight of the binder and/or the binder solution.
Such binder treatment may be performed at a level that may achieve the purpose of the above-described binder treatment. For example, the binder treatment may be performed such that a content of the binder satisfies 20 wt% or less, for example, a range of 8 wt% to 15 wt%, with respect to 100 wt% of a lyocell multifilament treated with an emulsion and a binder. In this case, the above content may refer to a dry weight after a solvent or liquid component that may be included in the binder has evaporated.
After the binder is applied onto the lyocell multifilament, the binder may be dried. A drying temperature is not particularly limited, but, for example, drying may be performed at room temperature (about 10 °C to about 35 °C).

<Other operations (g)>

After the crimp imparting, appropriate post-treatment may be additionally performed.
In an example, secondary emulsion treatment (g1) may be additionally performed. Through the secondary emulsion treatment, flexibility can be further provided to tow. The secondary emulsion treatment may be performed in the same manner as or in accordance with the emulsion treatment (d) described above.
In particular, the secondary emulsion treatment may be performed by treating a lyocell multifilament (for example, lyocell tow), which has undergone a process using a crimper, with an emulsion. The secondary emulsion treatment may function advantageously in various processes performed during the preparation of a filter for a smoking article. For example, the secondary emulsion treatment may allow fibers and filters to spread well even in air during a spreading process and also may restrict fibers from being cut during a stretching process.
The secondary emulsion treatment as described above may be performed before or after the binder treatment. Alternatively, the secondary emulsion treatment may be performed irrespective of whether the binder treatment is performed.
Even in a case in which the secondary emulsion treatment as described above is performed, a secondary emulsion treatment process may be performed such that a content or an OPU content of an emulsion in a material satisfies the range described above.
In an example, drying treatment (g2) may be additionally performed. Drying may be performed, for example, at a temperature in a range of 100 °C to 130 °C. A drying treatment manner or method is not particularly limited, and known technologies may be used. For example, the drying may be performed by applying hot air to a lyocell tow or allowing a lyocell multifilament to pass through a temperature-controlled room or leaving the lyocell material for a certain period of time.

<Stacking (h)>

After the crimp imparting, an operation of stacking the lyocell material may be further performed. In an exemplary method of preparing a lyocell material, the stacking may be performed by a stacking device.
In addition, in an exemplary method of preparing a lyocell material, the stacking device may include a body portion and a supply portion capable of performing pendulum motion, and the lyocell material may be supplied through the supply portion so that the lyocell material may be stacked.
FIG. 2 is a conceptual view of a stacking device. FIG. 2 illustrates a stacking device 100 including a body portion 110 and a supply portion 120. Referring to FIG. 2, the supply portion 120 is connected to the body portion 110, and the lyocell material is transported to the supply portion 120 through the body portion 110. The lyocell material transported to the supply portion 120 may be discharged from one end of the supply portion 120 so that the lyocell material may be stacked.
In addition, FIG. 2 conceptually illustrates the pendulum motion of the supply portion 120. The supply portion 120 may perform the pendulum motion from one side to the other side. For example, a supply portion 120a positioned at one side may be positioned at the other side together with a supply portion 120b through pendulum motion.
The one end of the supply portion 120 from which the lyocell material may be discharged may perform the pendulum motion from one side to the other side.
In addition, FIG. 2 illustrates a maximum angle θ formed between an axis of the pendulum motion and the supply portion 120b positioned at the other side, a horizontal length α of the pendulum motion, and a vertical length β of the pendulum motion. The supply portion 120 may perform the pendulum motion in a vertical direction of the lyocell material. Meanwhile, the stacking device 100 may be moved in a horizontal direction of the lyocell material.
In an exemplary method of preparing each lyocell material, the maximum angle θ of the pendulum motion may be 45° or less. In addition, in an exemplary method of preparing a lyocell material, the maximum angle θ of the pendulum motion may be 7° or more.
For example, an upper limit of the maximum angle θ may be 45° or less, 44° or less, 43° or less, 42° or less, 41° or less, 40° or less, 39° or less, 38° or less, 37° or less, 36° or less, 35° or less, 34° or less, 33° or less, 32° or less, 31° or less, 30° or less, 29° or less, 28° or less, 27° or less, 26° or less, 25° or less, 24° or less, 23° or less, 22° or less, 21° or less, 20° or less, 19° or less, 18° or less, 17° or less, 16° or less, 15° or less, 14° or less, 13° or less, 12° or less, 11° or less, 10° or less, 9° or less, or 8° or less. A lower limit of the maximum angle θ may be 7° or more, 8° or more, 9° or more, 10° or more, 11° or more, 12° or more, 13° or more, 14° or more, 15° or more, 16° or more, 17° or more, 18° or more, 19° or more, 20° or more, 21° or more, 22° or more, 23° or more, 24° or more, 25° or more, 26° or more, 27° or more, 28° or more, 29° or more, 30° or more, 31° or more, 32° or more, 33° or more, 34° or more, 35° or more, or 36° or more.
In an exemplary method of preparing each lyocell material, the maximum angle θ of the pendulum motion is in a range of 7° to 45°. For example, the maximum angle θ of the pendulum motion may be in a range of 9° to 45°, 10° to 45°, 22° to 45°, 30° to 45°, 36° to 45°, 7° to 37°, 9° to 37°, 10° to 37°, 22° to 37°, 30° to 37°, 36° to 37°, 7° to 31°, 9° to 31°, 10° to 31°, 22° to 31°, 30° to 41°, 7° to 23°, 9° to 23°, 10° to 23°, 22° to 23°, 7° to 11°, 9° to 11°, 10° to 11°, 7° to 10°, 9° to 10°, or 7° to 8°.
When the maximum angle θ satisfies such a numerical range, the stacking of the lyocell material may be performed more uniformly, and the post-processing properties of the lyocell material may be further improved. When the maximum angle θ satisfies the upper limit, an excessive change in speed of the pendulum motion can be prevented. As a result, it can be prevented that the lyocell material is mostly disposed at a side portion.
Meanwhile, a length γ of the supply portion may be calculated by using the maximum angle θ, the horizontal length α of the pendulum motion, and the vertical length β of the pendulum motion. For example, the square of the length γ of the supply portion is equal to the sum of the square of the horizontal length α and the square of the vertical length β. In addition, the length γ of the supply portion may be calculated as the product of the vertical length β and tan θ or as the product of the horizontal length α and cosec θ.
Meanwhile, in an exemplary method of preparing each lyocell material, the length γ of the supply portion may be in a range of 0.8 m to 5 m.
For example, an upper limit of the length γ of the supply portion may be 4.5 m or less, 4.0 m or less, 3.5 m or less, 3.0 m or less, 2.5 m or less, 2.0 m or less, 1.5 m or less, or 1.0 m or less. A lower limit of the length γ of the supply portion may be 1.0 m or more, 1.5 m or more, 2.0 m or more, 2.5 m or more, 3.0 m or more, 3.5 m or more, or 4.0 m or more.
For example, the length γ of the supply portion may be in a range of 1.0 m to 1.5 m, 1.0 m to 2.0 m, 1.0 m to 2.5 m, 1.0 m to 3.0 m, 1.0 m to 3.5 m, 1.0 m to 4.0 m, 1.0 m to 4.5 m, 1.5 m to 2.0 m, 1.5 m to 2.5 m, 1.5 m to 3.0 m, 1.5 m to 3.5 m, 1.5 m to 4.0 m, 1.5 m to 4.5 m, 2.0 m to 2.5 m, 2.0 m to 3.0 m, 2.0 m to 3.5 m, 2.0 m to 4.0 m, 2.0 m to 4.5 m, 2.5 m to 3.0 m, 2.5 m to 3.5 m, 2.5 m to 4.0 m, 2.5 m to 4.5 m, 3.0 m to 3.5 m, 3.0 m to 4.0 m, 3.0 m to 4.5 m, 3.5 m to 4.0 m, 3.5 m to 4.5 m, or 4.0 m to 4.5 m.
When the length γ of the supply portion satisfies such a numerical range, the stacking of the lyocell material can be performed more uniformly, and the post-processing properties of the lyocell material can be further improved. When the length γ of the supply portion satisfies the lower limit, an excessive increase of the maximum angle θ of the pendulum motion can be prevented. As a result, it can be prevented that the lyocell material is mostly disposed at the side portion.
In an exemplary method of preparing a lyocell material, the stacking may be performed such that Expression 1 below is satisfied. $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
In Expression 1, C₁ is a total weight of the central portion, and M₁ is a total weight of the side portions.
To satisfy Expression 1, the maximum angle θ, the length γ of the supply portion, and/or the vertical length A of the lyocell material may be adjusted.
In an exemplary method of preparing a lyocell material, the stacking may be performed such that Expression 1-1 below is satisfied. $100 (%) \geq \frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
In Expression 1-1, C₁ is the total weight of the central portion, and M₁ is the total weight of the side portions.
To satisfy Expression 1-1, the maximum angle θ, the length γ of the supply portion, and/or the vertical length A of the lyocell material may be adjusted.
In an exemplary method of preparing a lyocell material, the stacking of the lyocell material may be performed during the pendulum motion of the supply portion. The stacking of the lyocell material may be performed during the pendulum motion, and thus the vertical length A of the lyocell material may be adjusted and increased.
In an exemplary method of preparing a lyocell material, the pendulum motion of the supply portion may be performed at a constant speed. Alternatively, the pendulum motion of the supply portion may be performed at a variable speed. The speed of the pendulum motion may be maintained or adjusted, thereby adjusting a weight of the lyocell material disposed at the side portion and/or a weight of the lyocell material disposed at the central portion.
In an exemplary method of preparing a lyocell material, a ratio of a minimum movement speed V_min of the pendulum motion to a maximum movement speed V_max of the pendulum motion may exceed 0.7. In addition, the ratio of the minimum movement speed V_min of the pendulum motion to the maximum movement speed V_max of the pendulum motion may be 1 or less.
When the ratio of the minimum movement speed V_min of the pendulum motion to the maximum movement speed V_max of the pendulum motion satisfies such a numerical range, the stacking of the lyocell material can be performed more uniformly, and the post-processing properties of the lyocell material can be further improved. When the ratio of the minimum pendulum motion speed V_min to the maximum pendulum motion speed V_max satisfies a lower limit, it can be prevented that the lyocell material is mostly disposed at the side portion. As a result, the lyocell material can be better unwounded.

[Smoking article]

Although not particularly limited, a lyocell material prepared through the method may be included in a smoking article. The smoking article may be an aerosol-generating article. The aerosol-generating article may include an aerosol-generating material or an aerosol-forming substrate.
For example, the lyocell material may be included in a combustion-type cigarette. As another example, the lyocell material may be included in a heated cigarette, and the heated cigarette may be used together with an aerosol generating device.
For example, when used as a heated smoking article, the smoking article may be separately inserted into an aerosol generating device. Here, the aerosol generating device may include an accommodation groove in which an aerosol-generating article may be accommodated, and in addition, may include a heater for heating the aerosol-generating article to generate aerosol, a control unit for controlling the overall operation of the aerosol generating device, a battery for providing power used for operating the aerosol generating device, and a detector for recognizing that the aerosol-generating article has been inserted into the aerosol generating device.
The smoking article may include a tobacco medium portion, a filter for a smoking article, and a wrapper, wherein the filter for a smoking article may be positioned at one end portion of the tobacco medium portion, for example, a rear end portion or a front end portion. The tobacco medium portion and the filter for a smoking article may each include a single segment or may each independently include a plurality of segments.
The tobacco medium portion may include a tobacco material, and the tobacco material may include nicotine. In addition, the tobacco medium portion may additionally include one or more excipients.
The excipients may include a binder, a filler, and other additives. For example, a tobacco medium included in the tobacco medium portion may be prepared in the form of granules including a tobacco material, an excipient, and the like.
For example, a filler may be additionally included to constantly maintain the shape, strength, and mass of the tobacco medium portion. For example, the lyocell material may be included in the tobacco medium portion. In addition, the lyocell material may be used as a filler.
The wrapper may be subdivided into cigarette paper for wrapping the tobacco medium portion, filter wrapping paper for wrapping the filter, and a tipping wrapper for coupling the tobacco medium portion and the filter.

[Filter for smoking article]

A lyocell material may be used in a filter for a smoking article. The lyocell material may be lyocell tow. In an example, the lyocell tow includes a lyocell multifilament imparted with crimps.
For example, the present application relates to a filter for a smoking article. The filter for a smoking article may include a lyocell material, and the lyocell material may be identical to that described above. In addition, the filter for a smoking article may include lyocell tow, and the lyocell tow may be identical to that described above.
In addition, the lyocell material may include an emulsion in a content of 0.1 wt% or more with respect to 100 wt% of the total weight of the lyocell material. In addition, an emulsion component and a content according to a aspect of the present application are as described above.
In an example, a single fineness of a filament constituting the lyocell multifilament may be in a range of 1.67 dtex to 8.89 dtex (1.5 denier to 8.0 denier). A specific numerical value is as described above.
In an example, the lyocell multifilament imparted with crimps may be a lyocell tow having a total fineness of 1,667 tex to 6,111 tex (15,000 denier to 55,000 denier), and for example, the lyocell multifilament may be lyocell tow. A specific numerical value is as described above.
In an example, the lyocell multifilament imparted with crimps may have 3.94 to 23.62 crimps per centimeter (10 to 60 crimps per inch). A specific numerical value is as described above.
In an example, the filter for a smoking article may further include a binder on a surface of the lyocell multifilament imparted with crimps or between the lyocell multifilaments imparted with crimps. The binder can increase the hardness of a filter for a smoking article prepared from tow, thereby preventing problems such as filter jamming during a process of preparing a filter or a process of preparing a tobacco. Types, components, and contents of available binders are as described above.
In an example, the filter for a smoking article may further include wrapping paper (which may be referred to as wrapper paper, filter paper, or filter wrapping paper). For example, the wrapping paper may be porous paper or non-porous paper that may wrap the above-described lyocell tow and may maintain a filter shape (for example, a cylinder or circular column).
In a specific embodiment of the present application, the filter for a smoking article may have a certain shape and a certain size.
For example, the filter may have a rod shape. In particular, the filter for a smoking article may have a shape such as a cylinder.
In addition, the filter may have a length of, for example, 10 mm to 50 mm. In particular, the length of the filter may have a lower limit of 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, 35 mm or more, 40 mm or more, or 45 mm or more and an upper limit of 45 mm or less, 40 mm or less, 35 mm or less, 30 mm or less, 25 mm or less, 20 mm or less, or 15 mm or less.
In a aspect of the present application, the filter having the length may have a circular cross section, and a circumference of the circular cross section may be in a range of 10 nm to 40 mm. For example, the circumference of the filter may have a lower limit of 15 mm or more, 20 mm or more, 25 mm or more, 30 mm or more, or 35 mm or more, and an upper limit of 35 mm or less, 30 mm or less, 25 mm or less, 20 mm or less, or 15 mm or less.
In an example, the filter for a smoking article may include lyocell tow and filter wrapping paper. The lyocell tow and the filter wrapping paper are as described above, and thus descriptions thereof are omitted.
The wrapping paper may be porous paper or non-porous paper that may wrap the above-described lyocell tow and may maintain a filter shape (for example, a cylinder or circular column).
In an example, when porous wrapping paper is used, the wrapping paper may have a porosity of 10 coresta unit (CU) to 50,000 CU. A coresta unit may be defined as a volume flow rate (cm³min^-1) of air passing through a 1 cm² substrate sample (that is, porous wrapping paper) at a pressure difference of 1 kPa. In particular, a lower limit of the porosity of the wrapping paper may be, for example, 1,000 CU or more, 5,000 CU or more, 10,000 CU or more, 15,000 CU or more, 20,000 CU or more, 25,000 CU or more, 30,000 CU or more, 35,000 CU or more, 40,000 CU or more, or 45,000 CU or more, and an upper limit thereof may be, for example, 45,000 CU or less, 40,000 CU or less, 35,000 CU or less, 30,000 CU or less, 25,000 CU or less, or 20,000 CU or less. In an aspect of the present application, the wrapping paper may have a porosity in a range of 22,000 CU to 26,000 CU or 23,000 CU to 25,000 CU.
In an example, a basis weight of the wrapping paper may be in a range of 15 g/cm² to 60 g/cm². In particular, a lower limit of the basis weight of the wrapping paper may be, for example, 20 g/cm² or more, 25 g/cm² or more, 30 g/cm² or more, 35 g/cm² or more, 40 g/cm² or more, 45 g/cm² or more, 50 g/cm² or more, or 55 g/cm² or more, and an upper limit thereof may be, for example, 55 g/cm² or less, 50 g/cm² or less, 45 g/cm² or less, 40 g/cm² or less, 35 g/cm² or less, 30 g/cm² or less, 25 g/cm² or less, or 20 g/cm² or less. In a aspect of the present application, the wrapping paper may have a basis weight of 16 g/cm² or more, 17 g/cm² or more, 18 g/cm² or more, 19 g/cm² or more, 20 g/cm² or more, or 21 g/cm² or more, and 25 g/cm² or less, 24 g/cm² or less, 23 g/cm² or less, 22 g/cm² or less, or 21 g/cm² or less.
Although not particularly limited, a weight of a filter having a rod shape may be 50 mg or more. In particular, the weight of the filter may have, for example, a lower limit of 100 mg or more, 150 mg or more, or 200 mg or more, and an upper limit of 500 mg or less, 450 mg or less, 400 mg or less, 350 mg or less, 300 mg or less, 250 mg or less, or 200 mg or less.
Other filters for a smoking article and materials included therein are as described above, and thus descriptions thereof are omitted.

[Method of preparing filter for smoking article]

For example, the present application relates to a method of preparing a filter for a smoking article. The method may be a method of preparing a filter for a lyocell smoking article as described above and may be a method including the above-described method of preparing a lyocell material.
Regarding the method of preparing a filter for a smoking article, the remaining processes excluding preparing of a filter are the same as processes described in the lyocell material described above, and thus descriptions thereof are omitted. In addition, descriptions overlapping the above descriptions are also omitted.
The preparing of the filter may be appropriately performed by a person skilled in the art according to a known method. For example, the filter may be prepared by forming wrapping paper filled with a lyocell material into a rod shape. Alternatively, the filter may be prepared by cutting filter paper filled with a lyocell material with a rod shape into an appropriate length. The wrapping paper is as described above.
Although not particularly limited, before the filter paper is filled with the lyocell material, the lyocell material may be further subjected to opening or plasticizer treatment. A surface area of the lyocell material may be increased by opening the lyocell material. For example, the lyocell material may be opened by applying an external force in a length direction, a width direction, and/or a thickness direction.
For example, the lyocell material used in preparing a filter for a smoking article may be lyocell tow.
Although not particularly limited, the filter for a smoking article may additionally include known cellulose acetate multifilaments at a level that does not impede the purpose of the disclosure. The cellulose acetate multifilament may be mixed with a lyocell multifilament. The cellulose acetate multifilament may be included in a segment distinguished from a segment including the lyocell multifilament.

Advantageous Effects of Invention

According to the present application, there may be provided a lyocell material for a filter for a smoking article, which is capable of replacing commercialized cellulose acetate (CA), and a filter for a smoking article including the same. In particular, the post-processing properties of the lyocell material, for example, unwinding properties, can be improved by satisfying a predetermined plating index. As a result, process costs consumed to prepare a filter for a smoking article can be reduced.

Brief Description of Drawings

FIG. 1 is a top view of an exemplary lyocell material.
FIG. 2 is a conceptual view of a stacking device.

Mode for the Invention

Hereinafter, the operations and effects of the disclosure will be described in more detail through aspects of the disclosure. However, this is presented as an example of the disclosure, and the scope of the disclosure is not limited thereby.
A lyocell material was prepared through processes as described in Preparation Example below. Conditions not specifically described are within the scope of the above description.

[Preparation Example]

Cellulose pulp having an alpha-cellulose content of 93.9 % and a DPw of 820 was mixed with an NMMO/H₂O solvent having a propyl gallate content of 0.01 wt% to prepare a spinning dope for preparing a lyocell multifilament (for example, lyocell tow) having a concentration of 11 wt% with respect to 100 wt% of the total weight of the mixture. Then, while a spinning temperature of a spinning nozzle was maintained at 110 °C, a discharge amount and a spinning speed were appropriately adjusted, and the spinning dope was spun.
The spinning dope with a filament phase discharged from the spinning nozzle was supplied to a coagulating solution (a coagulating solution having a concentration of 75 wt% water and 25 wt% NMMO with respect to 100 wt% of the total weight of the coagulating solution and a temperature of about 25 °C) in a coagulation tank through an air gap section. In this case, cooling air in the air gap section primarily solidified the spinning dope at a temperature of 8 °C and an air flow rate of 200 Nm³/h. In addition, the concentration of the coagulating solution was continuously monitored by using a sensor and a refractometer.
A coagulated lyocell filament was washed. In particular, the filament was introduced into a traction roller, and NMMO remaining in the filament was removed by using a washing solution sprayed from a washing device. Then, the washed filament was immersed inside a bath containing a certain emulsion concentration.
The filament was treated at a pressure of 19.61 N/cm² (2 kgf/cm²) by using a nip roll installed in a bath discharge portion and was put into a crimp machine to provide wrinkles. In particular, a pressure of a press roller was set to 24.52 N/cm² (2.5 kgf/cm²), and a pressure of a doctor blade was set to 4.90 N/cm² (0.5 kgf/cm²) to impart crimps to a lyocell material.
The lyocell material imparted with crimps was stacked through a stacking device, thereby preparing a lyocell material.
Prepared lyocell tow has a single fineness of 2.22 to 8.89 dtex (2.0 to 8.0 denier), a total fineness of 3,333 to 6,111 tex (30,000 to 55,000 denier), and the number of crimps of 5.91 to 21.65 ea/cm (15 to 55 ea/inch).

Example 1

A lyocell material was prepared according to Preparation Example, wherein a length γ of a supply portion of a stacking device, a vertical length A of a stacked lyocell material, a maximum angle θ of a pendulum motion, and a ratio of a minimum movement speed V_min of the pendulum motion to a maximum movement speed V_max of the pendulum motion were as shown in Table 1 below.

Examples 2 to 6

Lyocell materials were prepared in the same manner as in Example 1, wherein a length γ of a supply portion, a vertical length A of a lyocell material, a maximum angle θ of a pendulum motion, and a ratio of a minimum movement speed V_min of the pendulum motion to a maximum movement speed V_max of the pendulum motion were as shown in Table 1 below.

Comparative Example 1

A lyocell material is prepared in the same manner as in Example 1, wherein a length γ of a supply portion, a vertical length A of a lyocell material, a maximum angle θ of a pendulum motion, and a ratio V_min/V_max of a minimum movement speed V_min of the pendulum motion to a maximum movement speed V_max of the pendulum motion were as shown in Table 1 below.

[Table 1]

Evaluation target	Length γ (m) of supply portion	Vertical length A (m)	Maximum angle θ (°) of pendulum motion	V_min/V_max (%)
Example 1	4	1	7.2	99.2
Example 2	3	1	9.6	98.6
Example 3	4	1.5	10.8	98.2
Example 4	2	1.5	22.0	92.7
Example 5	1	1	30.0	86.6
Example 6	1	1.2	36.9	80.0
Comparative Example 1	0.7	1	45.6	70.0

<Evaluation Example 1: Evaluation of weight ratio and productivity>

For the lyocell materials of Examples 1 to 6 and Comparative Example 1, a plating index was calculated according to Expression 1 below. In Expression 1, C₁ was an average weight of a central portion, and M₁ was an average weight of side portions. $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$

Meanwhile, one end of each lyocell material was towed using a spreader. When towing was continuously performed, the processability of the lyocell material and the productivity of a filter for a smoking article were evaluated to be excellent. In other words, when towing was continuously performed, excessive clumping of the lyocell material of a side portion was not confirmed, and the unwinding of the lyocell material was uniform during a towing. When towing is delayed or interrupted, the processability and productivity are evaluated to be insufficient. Evaluation results are shown in Table 2 below.

[Table 2]

Evaluation target	Weight ratio (%)	Evaluation results
Example 1	100	Excellence
Example 2	99	Excellence
Example 3	99	Excellence
Example 4	96	Excellence
Example 5	93	Excellence
Example 6	90	Excellence
Comparative Example 1	85	Poor

In particular, in the case of Comparison Example 1, excessive clumping of lyocells of a side portion was confirmed, and the unwinding of the lyocell material was not uniform during the towing. As a result, it was impossible to prepare a filter for a smoking article using the lyocell material of Comparative Example 1.

Claims

A lyocell material comprising lyocell multifilaments imparted with crimps,
wherein the lyocell material comprises a central portion and one or more side portions and satisfies Expression 1 below: $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$

wherein, in Expression 1,

C₁ is a total weight of the central portion, and

M₁ is a total weight of the side portions.
The lyocell material of claim 1, wherein the lyocell material comprises one or more turning points,
along a length of the lyocell material in a vertical direction, the turning points are each positioned at one of two ends in the vertical direction,

each of the side portions is a portion that is closer to the one of the two ends, and

the central portion is a portion that is closer to an exact center point between the two ends than to the one of the two ends.
The lyocell material of claim 2, wherein the number of the turning points is 3 to 30 ea.
The lyocell material of claim 1, satisfying Expression 1-1 below: $100 (%) \geq \frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
wherein, in Expression 1-1,

C₁ is a total weight of the central portion, and

M₁ is a total weight of the side portions.
The lyocell material of claim 4, wherein Expression 1-1 is satisfied for all of the side portions.
The lyocell material of claim 1, wherein a total weight of the lyocell multifilaments disposed at the central portion is less than or equal to a total weight of the lyocell multifilaments disposed at the side portions.
The lyocell material of claim 1, wherein the number of the crimps is 10 ea/inch to 60 ea/inch, and/or
the lyocell multifilaments have a single fineness of 1.5 to 11.0 denier, and/or

the lyocell multifilaments have a yarn fineness of 10,000 to 40,000 denier, and/or

the lyocell material has a total fineness of 15,000 to 55,000 denier.
The lyocell material of claim 1, wherein the lyocell multifilaments comprise one or more monofilaments, and
at least one of the one or more monofilaments has a multi-lobal cross section.
The lyocell material of claim 1, wherein the lyocell material is lyocell tow.
The lyocell material of claim 1, wherein the lyocell material is used for a filter for a smoking article, and/or
the lyocell material is not used for a tire cord or a garment.
A filter for a smoking article, comprising the lyocell material of any one of claims 1 to 10.
A smoking article comprising the filter for a smoking article of claim 11.
A method of preparing a lyocell material, the method comprising:
lyocell dope spinning; coagulation and lyocell multifilament obtainment;

washing; emulsion treatment; and

crimp imparting,

wherein the method further comprises stacking a lyocell material,

the stacking is performed by a stacking device,

the stacking device comprises a body portion and a supply portion capable of pendulum motion, and

the lyocell material is stacked by supplying the lyocell material through the supply portion.
The method of claim 13, wherein the method is performed to satisfy Expression 1 below: $\frac{C_{1}}{M_{1}} * 100 (%) > 85 (%)$
wherein, in Expression 1,

C₁ is a total weight of a central portion, and

M₁ is a total weight of side portions.
The method of claim 13, wherein a maximum angle of the pendulum motion is 45° or less, and/or
a ratio of a minimum movement speed (V_min) of the pendulum motion to a maximum movement speed (V_max) of the pendulum motion exceeds 0.7.