Lyocell dope, lyocell material, smoking article filter, smoking article, and methods of preparing the same

Abstract

The present disclosure relates to a lyocell dope, a lyocell material, a smoking article filter including the lyocell material, and a smoking article. The lyocell dope, the lyocell material, and the smoking article filter according to the present disclosure are capable of replacing conventional cellulose acetate materials and smoking article filters including the same.

Description

Technical Field

[0001] The present disclosure relates to a lyocell dope, a lyocell material, a filter including the same, a smoking article, and methods of preparing the same.Background Art

[0002] Until now, cellulose acetate fibers have been mainly used as a cigarette filter material. Although cellulose acetate is known to be a biodegradable substance, smoking article filters made of cellulose acetate maintain their original shape for about one to two years after being buried in soil, and require considerable time to fully biodegrade. In light of the volume and toxicity of not only discarded tobacco products that are used for smoking and then collected as waste and landfilled but also tobacco products that are thrown away in the environment and left unattended, further improvement in the biodegradability of smoking article filters is necessary. Accordingly, lyocell, which is more environmentally friendly than cellulose acetate, has recently been selected as a material to replace cellulose acetate.Disclosure of Invention Technical Problem

[0003] An objective of the present disclosure is to provide a ground pulp for improving the manufacturing processability of a lyocell dope.

[0004] Another objective of the present disclosure is to provide a lyocell dope having improved processability by including a predetermined amount of ground pulp.

[0005] Another objective of the present disclosure is to provide a lyocell material capable of replacing cellulose acetate, which has been commercialized as a smoking article filter.

[0006] Another objective of the present disclosure is to provide a lyocell material for smoking article filters that is environmentally friendly in its manufacturing process and exhibits excellent biodegradability upon disposal.

[0007] Another objective of the present disclosure is to provide a lyocell filter for smoking articles.

[0008] Another objective of the present disclosure is to provide a smoking article (e.g., a cigarette) that includes the lyocell filter.Solution to Problem

[0009] According to aspects of the present disclosure, a lyocell material, a filter including the same, a smoking article, and the like may be provided.

[0010] According to an aspect, a lyocell dope is provided, wherein the lyocell dope includes N-methylmorpholine N-oxide (NMMO) and ground pulp dissolved in the NMMO, a span value of a particle size of the ground pulp is 1.4 to 4.0, and the span value is calculated according to Formula 1 to be described later.

[0011] Additionally, according to another aspect, a lyocell material may be provided, the lyocell material including a crimped lyocell multifilament, wherein the lyocell multifilament is obtained by spinning a lyocell dope according to any one of the embodiments.

[0012] Additionally, according to another aspect, a lyocell filter for smoking articles may be provided, the lyocell filter including the lyocell material as described in this application.

[0013] According to another aspect, a smoking article including the lyocell material or the filter may be provided.

[0014] According to another aspect, methods of preparing the lyocell material, the filter including the lyocell material, and the smoking article may be provided.

[0015] In the present specification, the term 'ground pulp' may refer to a cellulose raw material with a controlled particle size, and may also be referred to as 'pulp', 'cellulose pulp', or 'pulp powder'. Additionally, the term 'ground pulp' may be understood to refer to a single pulp powder, may be understood to refer to a plurality of pulp powders, and may be understood to refer to the entirety of the pulp powder.

[0016] In the present specification, the term "smoking article" may refer to an article, such as a cigarette or a cigar, capable of generating an 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 reconstituted tobacco, cut tobacco, or cast-leaf tobacco. In addition, the smoking article may include a volatile compound.

[0017] As used herein, the term "crimp" or "crimped" may refer to the waviness, curliness, or undulating configuration imparted to materials such as fibers, (mono)filaments, multifilaments and / or yarns, inherently and / or through mechanical, thermal, or chemical processes. A crimp may be characterized by periodic deviations from a straight linear axis along the length of the material, fiber, (mono)filament, multifilament and / or yarn. One crimp of a material, fiber, (mono)filament, multifilament and / or yarn may be defined as one repetition unit of said periodic deviation. The presence of crimp contributes to properties such as elasticity, bulk, resilience, and texture in the material and fabrics made from it.

[0018] As used herein "D 10 " is a particle size at 10 % cumulative distribution, "D 90 " is a particle size at 90 % cumulative distribution, and "D 50 " is a particle size at 50 % cumulative distribution (volume distribution). The parameter D 90 can correctly be referred to as Dv(90). It indicates the point in the particle size distribution up to and including which 90% of the total volume of the material in the sample is "contained." For example, if the D 90 is 600 µm, this means that 90% of the sample based on the volume has a size of 600 µm or less. The definition for D 50 or Dv(50) is then the point in the particle size distribution below which 50% of the sample based on the volume is contained. Similarly, D 10 or Dv(10) is the point in the particle size distribution below which 10% of the sample based on the volume is contained. This definition has long been used in size distribution measurements by laser diffraction. The D 10 , D 50 and D 90 can be calculated in accordance with JIS-Z-8819-2 (2001). The particle size is measured using a laser diffraction method, for example, using a particle size analyzer from MALVEN (model name: Mastersizer 3000). The sample to be measured is dissolved in NMMO in the laser diffraction method.

[0019] As used herein, the term "span" of a volume-based size distribution indicates how far apart the D 10 and D 90 are from each other, normalized with the midpoint (D 50 ).

[0020] As used herein, the term "average particle size" can refer to the D 50 .

[0021] Unless otherwise defined herein, in a case where the characteristics of the lyocell material, the smoking article filter, or relevant components or configurations are affected by temperature, the temperature at which such characteristics are identified or measured may be room temperature. Room temperature, in the absence of intentional cooling or heating, may be, for example, from 10 to 35 °C, particularly from 15 to 35 °C, from 20 to 30 °C, or about 25 °C.

[0022] The present disclosure relates to a lyocell material. The lyocell material may be used in a smoking article, and although not specifically limited, the lyocell material may be used in a smoking article filter.

[0023] Hereinbelow, the present disclosure will be described in further detail.

[0024] According to an aspect, provided is a lyocell dope including N-methylmorpholine N-oxide (NMMO) and ground pulp dissolved in the NMMO, wherein a span value of a particle size of the ground pulp is 1.4 to 4.0, and the span value is calculated according to Formula 1 below: Span = D 90 − D 10 / D 50

[0025] In Formula 1, D 10 is a particle size of the ground pulp at 10 % cumulative distribution, D 90 is a particle size of the ground pulp at 90 % cumulative distribution, and D 50 is a particle size of the ground pulp at 50 % cumulative distribution. The particle size of the ground pulp is measured using laser diffraction, for example, using a particle size analyzer from MALVEN (model name: Mastersizer 3000).

[0026] In some embodiments, the span value of the particle size may be 1.4 or more.

[0027] In some embodiments, the span value of the particle size may be a value measured before the pulp is dissolved in NMMO.

[0028] In some embodiments, the D 90 of the ground pulp may be 800 µm or less.

[0029] In some embodiments, the D 90 of the ground pulp may be 150 µm or more.

[0030] In some embodiments, the average particle size of the ground pulp may be 400 µm or less.

[0031] In some embodiments, the average particle size of the ground pulp may be 80 µm or more.

[0032] In some embodiments, the D 10 of the ground pulp may be 120 µm or less.

[0033] In some embodiments, the D 10 of the ground pulp may be 10 µm or more.

[0034] In some embodiments, all of the ground pulp may have a particle size of 900 µm or less.

[0035] In some embodiments, all of the ground pulp may have a particle size of 10 µm or more.

[0036] In some embodiments, the flow rate deviation of the ground pulp may be 10.0 % or less.

[0037] In some embodiments, the flow rate deviation of the ground pulp may be 2.0 % or more.

[0038] The lyocell dope according to some embodiments may further include water (H 2 O).

[0039] In some embodiments, with respect to 100 parts by weight of the total lyocell dope, the weight of the ground pulp may be 5 parts by weight to 15 parts by weight.

[0040] In some embodiments, with respect to 100 parts by weight of the total lyocell dope, the weight of the aqueous NMMO solution may be 85 parts by weight to 95 parts by weight.

[0041] In some embodiments, the aqueous NMMO solution may include 80 to 95 parts by weight of NMMO and 5 to 20 parts by weight of H 2 O.

[0042] Further, according to another aspect, provided is a lyocell material including a crimped lyocell multifilament, wherein the lyocell material has a first fineness deviation of 11.0 % or less, and the first fineness deviation is calculated according to Formula 5 below. To calculate the first fineness deviation, a plurality of first samples may be prepared, and a first fineness may be measured from each of the plurality of first samples.

[0043] In Formula 5, the first maximum fineness is the largest value among the finenesses of the first samples, the first minimum fineness is the smallest value among the finenesses of the first samples, and the first average fineness is the average value of the finenesses of the first samples, wherein the fineness of each first sample is calculated according to Formula 5-1 below. In some embodiments, the number of the first samples can be 100.

[0044] In some embodiments, the length of the first sample may be 90 m.

[0045] In some embodiments, the first sample may be a skein-type sample.

[0046] In some embodiments, before the first fineness deviation is calculated, the first sample may be stabilized under constant temperature and constant humidity conditions. For example, the constant temperature condition may be 20 °C, and the constant humidity condition may be 65 %RH. Additionally, the stabilization may be performed for about 24 hours.

[0047] In some embodiments, the first fineness deviation may be 4 % or more.

[0048] In some embodiments, the second fineness deviation is 21 % or less, and the second fineness deviation may be calculated according to Formula 6 below. To calculate the second fineness deviation, a plurality of second samples may be prepared, and a fineness of a second sample may be measured from each of the plurality of second samples.

[0049] In Formula 6, the second maximum fineness is the largest value among the finenesses of the second samples, the second minimum fineness is the smallest value among the finenesses of the second samples, and the second average fineness is the average value of the finenesses of the second samples, and the fineness of each second sample is calculated according to Formula 6-1 below. In some embodiments, the number of the second samples can be 100. Fineness of second sample = Weight of second sample g * 10000

[0050] In some embodiments, the length of the second sample may be 90 cm.

[0051] In some embodiments, before the second fineness deviation is calculated, the second sample may be stabilized under constant temperature and constant humidity conditions. For example, the constant temperature condition may be 20 °C, and the constant humidity condition may be 65 %RH. Additionally, the stabilization may be performed for about 24 hours.

[0052] In some embodiments, before the second fineness deviation is calculated, a load may be applied to the second sample. By applying the load, the second sample may be additionally stabilized. For example, the load may be 2 kg.

[0053] In some embodiments, the second fineness deviation may be 11.0 % or more.

[0054] In some embodiments, the lyocell multifilament is obtained by spinning a lyocell dope, the lyocell dope includes N-methylmorpholine N-oxide (NMMO) and ground pulp dissolved in the NMMO, the span value of the particle size of the ground pulp is 1.4 to 4.0, and the span value may be calculated according to Formula 1 below. Span = D 90 − D 10 / D 50

[0055] In Formula 1, D 10 is a particle size of the ground pulp at 10 % cumulative distribution, D 90 is a particle size of the ground pulp at 90 % cumulative distribution, and D 50 is a particle size of the ground pulp at 50 % cumulative distribution.

[0056] The particle size of the ground pulp is measured using laser diffraction, for example, using a particle size analyzer from MALVEN (model name: Mastersizer 3000).

[0057] In some embodiments, provided is a lyocell material including a lyocell multifilament obtained by spinning the lyocell dope as described in this application.

[0058] In some embodiments, the number of crimps may be 3.94 crimps / cm (10 crimps / inch) to 23.64 crimps / cm (60 crimps / inch).

[0059] In some embodiments, the number of crimps may be 9.84 crimps / cm (25 crimps / inch) to 19.68 crimps / cm (50 crimps / inch)

[0060] In some embodiments, the single filament fineness of the lyocell multifilament may be 1.67 dtex to 8.89 dtex (1.5 to 8.0 denier).

[0061] In some embodiments, the lyocell material may have a total fineness of 1,667 tex to 6,111 tex (15,000 to 55,000 denier).

[0062] The lyocell material according to some embodiments may be a lyocell tow.

[0063] The lyocell material according to some embodiments may be for a smoking article filter.

[0064] The lyocell material according to some embodiments may not be for apparel use or for tire cord use.

[0065] Additionally, according to another aspect, a filter for a smoking article is provided, including any one of the lyocell materials according to an embodiment.

[0066] Additionally, according to another aspect, a smoking article is provided, including any one of the filters for a smoking article as described in this application.

[0067] Additionally, a method of preparing a lyocell material is provided, the method including: preparing a lyocell dope including a ground pulp; spinning the lyocell dope; coagulating to obtain a lyocell multifilament; washing; treating with emulsion; and imparting crimp wherein a flow rate deviation of the ground pulp is 10.0 % or less.

[0068] In some embodiments, a pressure deviation of the lyocell dope may be 15 % or less.

[0069] Additionally, according to another aspect, a method of preparing a lyocell material is provided, the method including: preparing a lyocell dope; spinning the lyocell dope; coagulating to obtain a lyocell multifilament; washing; treating with emulsion; and imparting crimp, wherein a span value of a particle size of ground pulp included in the lyocell dope is 1.4 to 4.0, and the span value is calculated according to Formula 1 below. Span = D 90 − D 10 / D 50

[0070] In Formula 1, D 10 is a particle size of the ground pulp at 10 % cumulative distribution, D 90 is a particle size of the ground pulp at 90 % cumulative distribution, and D 50 is a particle size of the ground pulp at 50 % cumulative distribution.

[0071] The particle size of the ground pulp is measured using laser diffraction, for example, using a particle size analyzer from MALVEN (model name: Mastersizer 3000).

[0072] In some embodiments, the D 90 of the ground pulp may be 800 µm or less.

[0073] In some embodiments, the D 90 of the ground pulp may be 150 µm or more.

[0074] In some embodiments, the average particle size of the ground pulp may be 400 µm or less.

[0075] In some embodiments, the average particle size of the ground pulp may be 80 µm or more.

[0076] In some embodiments, the D 10 of the ground pulp may be 120 µm or less.

[0077] In some embodiments, the D 10 of the ground pulp may be 10 µm or more.

[0078] In some embodiments, the particle size of all of the ground pulp may be 900 µm or less.

[0079] In some embodiments, the particle size of all of the ground pulp may be 10 µm or more.

[0080] In some embodiments, the flow rate deviation of the ground pulp may be 10.0 % or less.

[0081] In some embodiments, the flow rate deviation of the ground pulp may be 2.0 % or more.

[0082] The lyocell dope according to some embodiments may further include water (H 2 O).

[0083] In some embodiments, with respect to 100 parts by weight of the total lyocell dope, the weight of the ground pulp may be 5 parts by weight to 15 parts by weight.

[0084] In some embodiments, with respect to 100 parts by weight of the total lyocell dope, the weight of the aqueous NMMO solution may be 85 parts by weight to 95 parts by weight.

[0085] In some embodiments, the aqueous NMMO solution may include 80 to 95 parts by weight of NMMO and 5 to 20 parts by weight of H 2 O.

[0086] The lyocell material according to some embodiments is obtained by spinning a lyocell dope with controlled properties. Specifically, the lyocell dope includes ground pulp whose span value of particle size is controlled to be 4.0 or less. By controlling the span value to be 4.0 or less, the uniformity of the ground pulp may be secured, and the ground pulp may be completely dissolved in NMMO. By controlling the span value to be 4.0 or less, the uniformity of the ground pulp may be secured, and the ground pulp may be completely dissolved in NMMO. Additionally, the flow rate deviation of the ground pulp may be 10 % or less, and the processability of the process for transferring the ground pulp may be improved.

[0087] As a result, the uniformity of the lyocell dope may be improved, the spinnability of the lyocell dope may be improved, and the uniformity of the lyocell mono-filament and the lyocell multifilament obtained by spinning from the lyocell dope may be improved. Furthermore, as the uniformity of the lyocell multifilament is improved, the processability of the lyocell multifilament is improved, and the uniformity and processability of the lyocell material including the lyocell multifilament may be improved.

[0088] On the other hand, if the lyocell dope includes ground pulp with a span value exceeding 4.0, incompletely dissolved ground pulp particles may be included in the lyocell dope. The incompletely dissolved ground pulp may be adsorbed onto the nozzles of the spinneret, causing a degradation in the performance of the spinning apparatus, and may be a cause of nozzle blockage.

[0089] Additionally, if the lyocell dope includes pulp with a span value exceeding 4.0, the uniformity of the lyocell dope is degraded, and the uniformity of the lyocell mono-filament and the lyocell multifilament obtained therefrom may be degraded. As a result, the uniformity and processability of the lyocell material including the lyocell multifilament may be degraded.[Non-Circular Cross-Section]

[0090] One or more lyocell monofilaments included in the lyocell material of the present disclosure may have a non-circular cross-section. As used herein, "non-circular" means that the outline of the cross-section is not circular, and "cross-section" may be a cross-section obtained by imaginary or actually cutting the lyocell monofilament in a direction perpendicular to its length direction.

[0091] The outline of the non-circular cross-section may be in contact with both a first imaginary circle and a second imaginary circle. In addition, the second imaginary circle may be depicted within the first imaginary circle.

[0092] The first imaginary circle may be the circle, drawn so as to include the entire cross-section of the monofilament, that has the smallest possible area among all such circles. The second imaginary circle may be the circle, drawn within the cross-section of the monofilament, that has the largest possible area among all such circles.

[0093] In cases where a circumscribed circle can be drawn around the cross-section of the monofilament, the imaginary first circle may be that circumscribed circle. In cases where an inscribed circle can be drawn within the cross-section of the monofilament, the imaginary second circle may be that inscribed circle.

[0094] The non-circular cross-section may include multiple protrusions, and for example, may be a Y-shaped cross-section having three protrusions. It may be understood that such multiple protrusions are integrally formed around the imaginary second circle as a central portion, with their tips coming into contact with the imaginary first circle.

[0095] The degree of non-circularity of the monofilament may be defined according to Mathematical Formula 1 below. Degree of non − circularity = r 1 / r 2

[0096] In this formula, r1 is the radius of the first imaginary circle, and r2 is the radius of the second imaginary circle.

[0097] For example, the radius of the first imaginary circle may be from 4 to 40 µm, the radius of the second imaginary circle may be from 2 to 14 µm, and the degree of non-circularity may be from 1.01 to 10.

[0098] In addition, the space occupancy of the monofilament may be defined according to Mathematical Formula 2. Space occupancy = S 1 / S 2 × 100 %

[0099] In this formula, S1 is the area of the first imaginary circle, and S2 is the cross-sectional area of the monofilament included in the lyocell fiber.

[0100] For example, the space occupancy of a monofilament having a non-circular cross-section may be from 120 to 600 %.[Fineness]

[0101] The lyocell material of the present disclosure includes a lyocell multifilament, and this lyocell multifilament may have a fineness suitable for manufacturing a smoking article filter and ensuring its functionality.

[0102] In some embodiments, filaments constituting the lyocell multifilament may have a single filament fineness of 1.67 dtex to 8.89 dtex (1.5 to 8.0 denier). Here, the single filament fineness of the filaments refers to the fineness of a single monofilament separated from the multifilament. In other words, the single fiber fineness of a filament constituting the lyocell multifilament refers to the monofilament fineness.

[0103] The single filament fineness of the filaments 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). The single filament fineness of the filaments may have, for example, a lower limit of 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. Meeting the aforementioned range may be more advantageous for ensuring stable physical properties of a smoking article filter (e.g., achieving appropriate hardness or draw resistance) and maintaining reliable processing performance.

[0104] In some embodiments, the total fineness of the lyocell multifilament may be 1,667 tex to 6,111 tex (15,000 to 55,000 denier), and the total fineness of the lyocell material may be calculated as the sum of the finenesses of the lyocell monofilaments. For example, the 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 (51,000 denier) 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. Furthermore, the 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. If the total fineness falls outside the aforementioned range, the process reliability for manufacturing a smoking article filter may deteriorate (making continuous processing impossible due to cutting). In addition, during the production of the smoking article filter, if the amount of tow inserted into the filter wrapper becomes too little or too much, achieving adequate filter properties (e.g., hardness or draw resistance) may become difficult.

[0105] While the method for measuring fineness is not particularly limited, one example is as follows. A 2 m sample of the lyocell material, such as a lyocell tow, is collected. The sample is then conditioned for 24 hours in a room maintained at a constant temperature of 20 °C and constant humidity of 65 % RH. One end of the conditioned lyocell tow is fixed, and a 2 kg load is attached to the opposite end. While elongated under the load, the tow is held for 5 seconds (to stabilize), then cut to a length of 90 cm to obtain a crimped sample, and the weight of this sample is measured (total fineness). Fineness is converted to a value obtained by multiplying the measured weight by 10,000 according to the denier conversion method. Dividing the total fineness of the sample by the number of monofilaments in the sample yields the single-filament fineness of the monofilaments in the sample.

[0106] The total fineness of the aforementioned lyocell multifilament may be determined by the single-filament fineness and the number of crimps. In the present disclosure, both the single-filament fineness and the number of crimps may be controlled, thereby allowing the total fineness of the lyocell material to be suitably maintained for manufacturing a smoking article filter and ensuring its functionality.

[0107] The lyocell material according to some embodiments may include a lyocell multifilament with improved uniformity. As a standard for evaluating the uniformity of the lyocell material, the fineness deviation of the lyocell multifilament and / or the lyocell material may be utilized.

[0108] The fineness deviation of the lyocell multifilament may refer to the deviation in fineness measured from the lyocell multifilament before crimps are imparted. The fineness deviation of the lyocell multifilament may also be referred to as a first fineness deviation.

[0109] Before the first fineness deviation is measured, the lyocell multifilament may be stabilized. As described above, this stabilization may be performed by leaving the lyocell multifilament for 24 hours under constant temperature conditions of 20 °C and constant humidity conditions of 65 % RH.

[0110] For the measurement of the first fineness deviation, a skein-type sample may be collected from the lyocell multifilament. Although not particularly limited, the skein-type sample may be prepared using a denier creel with a circumference of 1.125 m, and may be prepared to have a length of 90 m. The skein-type sample may also be referred to as a first sample.

[0111] For the calculation of the first fineness deviation, a plurality of first samples may be prepared. For example, 20 or more first samples may be prepared, and preferably 50 or more first samples may be prepared, preferably 100. A first fineness may be measured from each of the plurality of first samples.

[0112] From each first sample, the fineness of the first sample may be respectively measured according to Formula 5-1. Among the measured finenesses of the first samples, the largest value may be selected as the first maximum fineness, the smallest value may be selected as the first minimum fineness, and the average value of the measured first finenesses may be selected as the first average fineness.

[0113] In some embodiments, the first fineness deviation may be 11.0 % or less. More specifically, the upper limit of the first fineness deviation may be 10.5 % or less, 10.0 % or less, 9.5 % or less, 9.0 % or less, 8.5 % or less, 8.0 % or less, 7.5 % or less, 7.0 % or less, 6.5 % or less, 6.0 % or less, 5.5 % or less, 5.0 % or less, or 4.5 % or less. As the first fineness deviation satisfies the upper limit value, the uniformity of the fineness of the lyocell multifilament may be secured. As a result, the uniformity of the crimps imparted to the lyocell multifilament may be improved. Additionally, the uniformity of the lyocell material including the lyocell multifilament may be improved. As will be described later, the improvement in the uniformity of the lyocell material can lead to an improvement in the quality of a filter including the lyocell material.

[0114] Additionally, although not particularly limited, the first fineness deviation may be 0.5 % or more. More specifically, the lower limit of the first fineness deviation may be 1.0 % or more, 1.5 % or more, 2.0 % or more, 2.5 % or more, 3.0 % or more, 3.5 % or more, or 4.0 % or more.

[0115] Meanwhile, the fineness deviation of the lyocell material may refer to the deviation in fineness measured from a crimped lyocell multifilament. The fineness deviation of the lyocell material may also be referred to as a second fineness deviation.

[0116] Before the second fineness deviation is measured, the lyocell material may be stabilized. As described above, the stabilization may be performed by leaving the lyocell material for 24 hours under constant temperature conditions of 20 °C and constant humidity conditions of 65 % RH.

[0117] For the measurement of the second fineness deviation, a sample of a predetermined length may be collected from the lyocell material. Although not particularly limited, the length of the sample may be 2 m. For additional stabilization, a load of a predetermined weight may be applied to the sample. The predetermined weight may be 2 kg. After the load is applied, the sample may be cut to a length of 90 cm, and a sample with a length of 90 cm may also be referred to as a second sample.

[0118] For the calculation of the second fineness deviation, a plurality of second samples may be prepared. From the plurality of second samples, the fineness of each second sample may be measured. For example, 20 or more second samples may be prepared, and preferably 50 or more, preferably 100, second samples may be prepared.

[0119] From each second sample, the fineness of the second sample may be respectively measured according to Formula 6-1. The second maximum fineness is the largest value among the finenesses of the second samples, the second minimum fineness is the smallest value among the finenesses of the second samples, and the second average fineness may be the average value of the finenesses of the second samples. Fineness of second sample = Weight of second sample g * 10000

[0120] In some embodiments, the second fineness deviation may be 21.0 % or less. More specifically, the upper limit of the second fineness deviation may be 20.5 % or less, 20.0 % or less, 19.5 % or less, 19.0 % or less, 18.5 % or less, 18.0 % or less, 17.5 % or less, 17.0 % or less, 16.5 % or less, 16.0 % or less, 15.5 % or less, 15.0 % or less, 14.5 % or less, 14.0 % or less, 13.5 % or less, 13.0 % or less, 12.5 % or less, 12.0 % or less, or 11.5 % or less. By the second fineness deviation satisfying the aforementioned upper limit value, the fineness uniformity of the lyocell material may be ensured. As a result, the uniformity of the lyocell material itself may be secured. When the fineness of the lyocell material is made uniform, preferred characteristics of the lyocell material may be reliably achieved, and fineness-related properties of the lyocell material may be improved.

[0121] For example, the lyocell material may exhibit consistent mechanical properties, breakage may be suppressed, and a filter containing the lyocell material may reliably maintain a filtration performance above a certain level. As a result, the quality of the filter containing the lyocell material may be further improved.

[0122] Although not particularly limited, the second fineness deviation may be 0.5 % or more. More specifically, the lower limit of the second fineness deviation may be 1.0 % or more, 1.5 % or more, 2.0 % or more, 2.5 % or more, 3.0 % or more, 3.5 % or more, 4.0 % or more, 4.5 % or more, 5.0 % or more, 5.5 % or more, 6.0 % or more, 6.5 % or more, 7.0 % or more, 7.5 % or more, 8.0 % or more, 8.5 % or more, 9.0 % or more, 9.5 % or more, 10.0 % or more, 10.5 % or more, or 11.0 % or more.[Number of Crimps]

[0123] In some embodiments, the lyocell multifilament may have 3.94 to 19.71 crimps per centimeter (10 to 50 crimps per inch). For example, the number of crimps may be 5.91 crimps / cm (15 crimps / inch) or more, 7.87 crimps / cm (20 crimps / inch) or more, 9.84 crimps / cm (25 crimps / inch) or more, 11.81 crimps / cm (30 crimps / inch) or more, 13.78 crimps / cm (35 crimps / inch) or more, 15.75 crimps / cm (40 crimps / inch) or more, or 17.72 crimps / cm (45 crimps / inch) or more. The upper limit of the number of crimps may be, for example, 17.72 crimps / cm (45 crimps / inch) or less, 15.75 crimps / cm (40 crimps / inch) or less, 13.78 crimps / cm (35 crimps / inch) or less, 11.81 crimps / cm (30 crimps / inch) or less, or 9.84 crimps / cm (25 crimps / inch) or less. The number of crimps and its uniformity may be controlled through pressure and temperature conditions associated with the crimping process described below.

[0124] Although not particularly limited thereto, the number of crimps may be measured using single-fiber property evaluation equipment (for example, a Favimat). Specifically, the produced lyocell material (preferably, a lyocell tow) sample may be left under conditions of a temperature of 20±2 °C and a humidity of 65±4 % for 24 hours to stabilize. A test specimen may be taken in a way that preserves the crimp in the stabilized sample. The collected test specimen may be mounted on a dedicated jig with a gauge length of 10 to 30 mm. The initial load during measurement may be 0.45 g / tex (0.05 g / denier), and the crimp sensitivity may be 0.01 mm. The number of crimps may be measured under the conditions as described above (i.e., conditions of a temperature of 20±2 °C and a humidity of 65±4 %).

[0125] Although not particularly limited, a lyocell material prepared to satisfy the single filament fineness, total fineness, and / or number of crimps as described above may be used in a smoking article.[Binder]

[0126] In some embodiments, the lyocell material may further include a binder. For example, the binder may be present on the surface of the lyocell multifilament or between the lyocell multifilaments (or monofilaments). By further increasing the hardness of the smoking article filter, the binder may prevent issues such as the filter getting stuck during filter manufacturing or smoking article (e.g., cigarette) production.

[0127] The type of binder that may be used is not particularly limited, and any known binder may be employed so long as it does not impair the objectives of the present disclosure. For example, a binder that can offer sufficient compatibility with the emulsion used in the present disclosure, improve the hardness of the filter, and provide excellent bonding strength may be utilized.

[0128] In a non-limiting example, the binder may include a polyester-based binder, a cellulose-based binder, and / or a vinyl-based binder.

[0129] Although not particularly limited thereto, the polyester-based binder may be a polyester binder including one or more selected from the group consisting of alkylene, arylene, or heteroarylene groups having a carbon number of 5 to 12.

[0130] As the cellulose-based binder, for example, hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC) and / or methylcellulose (MC), carboxymethylcellulose (CMC), and the like may be used, but the disclosure is not limited to the foregoing.

[0131] According to certain embodiments, the cellulose-based binder is selected from the group consisting of hydroxypropyl methyl cellulose (HPMC), ethyl cellulose (EC), methyl cellulose (MC), carboxymethyl cellulose (CMC), or a combination thereof.

[0132] As the vinyl-based binder, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), ethylene-vinyl acetate (EVAc), or the like may be utilized without being limited thereto.

[0133] According to certain embodiments, the vinyl-based binder is selected from the group consisting of polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), ethylene vinyl acetate (EVAc), or a combination thereof.

[0134] A method for applying (coating) the binder to the lyocell material will be described later.[Emulsion]

[0135] The lyocell material may include: a lyocell multifilament; and an emulsion coating the lyocell multifilament. In addition, the emulsion includes (a) an esterification product of a fatty acid having a carbon number of 16 or more and an aliphatic monohydric alcohol; and (b) an esterification product of sorbitan and a fatty acid having a carbon number of 16 or more. Such an emulsion may be applied to part or all of the mono- or multifilaments constituting the lyocell material. In addition, the emulsion may penetrate between the filaments.

[0136] The emulsion containing at least the aforementioned components (a) and (b) may have hydrophobicity. As a result, the lyocell material treated with the emulsion has excellent spreadability.

[0137] In some embodiments of the present disclosure, the lyocell material may contain the emulsion in a predetermined amount. Here, the emulsion content may be expressed as OPU (wt%) as described below. "OPU" may denote "oil pick up ratio". For example, the lyocell material may include the emulsion in an amount of 0.1 wt% or more based on 100 wt% of the total lyocell material. Specifically, the emulsion content 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, 3.0 wt% or more, more specifically, 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. Furthermore, the upper limit of the emulsion content 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, 10.0 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.

[0138] A method for measuring the emulsion content (OPU) may, for example, employ an extrusion technique. For example, a sample (e.g., 2 to 5 g, specifically about 2.5 g) is taken (the weight of this sample is referred to as the "sample weight") and placed into a syringe-shaped container. Although not particuarly limited, the material of the container may be stainless steel (SUS). Next, a solvent (e.g., methanol) is added to the container containing the sample (the amount of the solvent added may be 10 ml or less (e.g., about 8 ml)). The solvent is added dropwise to the sample, and the drop rate is controlled to be uniform. The solvent thus introduced into the container is then allowed to drop from one end of the syringe-shaped container onto a plate. The plate is pre-weighed (this weight is referred to as "plate weight A"), and the plate is installed such that the solvent dropped thereon can be driven off (i.e., evaporated) at a temperature of 120 to 130 °C (e.g., 125 °C). The solvent introduction and dropping process is repeated three times. Thereafter, a pressure (e.g., 98 N / cm 2< (10 kgf / cm 2< ) or less, 49 N / cm 2< (5 kgf / cm 2< ) or less, or 20 to 39 N / cm 2< (2 to 4 kgf / cm 2< )) is applied to the sample once using the syringe-shaped container. Through this process, the solvent and emulsion present in the sample can be sufficiently expelled. Pressure may continue to be applied until no further solvent is discharged from the sample. Thereafter, the plate is placed in a desiccator for 5 minutes to 10 minutes, and the weight of the plate with the sample is measured (plate weight B). The emulsion content is calculated according to the following Formula:

[0139] In addition, the lyocell material used as the basis for emulsion content may be a lyocell multifilament that has undergone at least one emulsion treatment. For example, the lyocell material may be a lyocell multifilament to which a first emulsion treatment (described below) has been applied, a lyocell multifilament to which both first emulsion treatment and second emulsion treatment (described below) have been applied, or a lyocell multifilament to which the aforementioned emulsion treatment(s) as well as the binder (described below) have been applied. In addition, the lyocell multifilament treated with the emulsion and / or binder may have crimps imparted thereto.

[0140] With respect to the emulsion of the present disclosure, the component (a) is a compound that can function as a lubricant or oil, and is a substance safe enough for use in food for human consumption. The component (a) imparts lubricity to the fiber entering a crimper. Insufficient lubricity may cause the lyocell to bunch up and fail to exit the crimper, while excessively high lubricity may lead to poor crimp formation. Taking these functions into consideration, the content of the component (a) may be controlled as described below.

[0141] There is no particular limitation on the type of fatty acid having a carbon number of 16 or more used to form the component (a). A fatty acid having a carbon number of 16 or more, capable of forming an esterification product safe enough for use in food for human consumption, may be used.

[0142] In some embodiments, the fatty acid is selected from the group consisting of palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, palmitoleic acid, oleic acid, linoleic acid, and arachidonic acid.

[0143] For example, the fatty acid having a carbon number of 16 or more may be a saturated fatty acid and / or an unsaturated fatty acid.

[0144] Examples of the saturated fatty acid include palmitic acid (hexadecanoic acid, CH 3 (CH 2 ) 14 COOH), margaric acid (heptadecanoic acid, CH 3 (CH 2 ) 15 COOH), stearic acid (octadecanoic acid, CH 3 (CH 2 ) 16 COOH), nonadecylic acid (nonadecanoic acid, CH 3 (CH 2 ) 17 COOH), or arachidic acid (eicosanoic acid, CH 3 (CH 2 ) 18 COOH). According to certain embodiments the saturated fatty acid is selected from the group consisting of palmitic acid (hexadecanoic acid, CH 3 (CH 2 ) 14 COOH), margaric acid (heptadecanoic acid, CH 3 (CH 2 ) 15 COOH), stearic acid (octadecanoic acid, CH 3 (CH 2 ) 16 COOH), nonadecylic acid (nonadecanoic acid, CH 3 (CH 2 ) 17 COOH), arachidic acid (eicosanoic acid, CH 3 (CH 2 ) 18 COOH), or a combination thereof. However, the types of saturated fatty acids that can be used are not limited to the aforementioned examples.

[0145] Examples of the unsaturated fatty acid include palmitoleic acid (CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH), oleic acid (CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH), linoleic acid (C 13 H 32 O 2 ), arachidonic acid (C 20 H 32 O 2 ), and the like. However, the types of unsaturated fatty acids that can be used are not limited to the aforementioned examples.

[0146] According to certain embodiments the unsaturated fatty acid is selected from the group consisting of palmitoleic acid (CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH), oleic acid (CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH), linoleic acid (C 18 H 32 O 2 ), arachidonic acid (C 20 H 32 O 2 ), or combination thereof.

[0147] Although not particularly limited, the upper limit on the carbon number of the fatty acid having a carbon number of 16 or more may be, for example, 40 or less, 36 or less, 32 or less, 28 or less, 24 or less, or 20 or less.

[0148] There is no particular limitation on the type of aliphatic monohydric alcohol used to form the component (a). An aliphatic monohydric alcohol capable of forming an esterification product safe enough for use in food for human consumption may be used.

[0149] For example, the aliphatic monohydric alcohol may be either a saturated or unsaturated aliphatic alcohol, which may take a linear or branched form.

[0150] In some embodiments, the aliphatic monohydric alcohol may have a carbon number of 1 to 40. Specifically, the aliphatic monohydric alcohol may have a carbon number of, for example, 4 or more, 8 or more, 12 or more, 16 or more, or 20 or more.

[0151] Examples of such aliphatic monohydric alcohols may include methanol, ethanol, butanol, lauryl alcohol, isotridecanol, and stearyl alcohol, without being 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.

[0152] In some embodiments of the present disclosure, an esterification product of isotridecanol and stearic acid (e.g., isotridecyl stearate) may be used as the component (a). However, the type of component (a) that can be used is not limited to the foregoing.

[0153] As will be described below, the content of component (a) in the emulsion may be controlled in consideration of the intended function of component (a) and that of the emulsion.

[0154] The component (b), which is an esterification product of sorbitan and a fatty acid having a carbon number of 16 or more, is a compound that can function as an emulsifier and is a substance safe enough for use in food for human consumption.

[0155] Because the component (b) has both hydrophilic and hydrophobic properties due to polyhydric alcohol (i.e., sorbitan), it facilitates the dispersion of component (a), which imparts lubricity to the fibers, in water as described below. Moreover, when used together, the components (a) and (b) not only enhance the dispersibility of the emulsion as mentioned above, but also lower the melting point to ensure ease of handling and stability of the emulsion. The content of the component (b) may be controlled in consideration of the aforementioned functions, as described below.

[0156] There is no particular limitation placed on the type of fatty acid having a carbon number of 16 or more used to form the component (b). A fatty acid having a carbon number of 16 or more that can yield an esterification product safe enough for use in food for human consumption, may be used.

[0157] For example, the fatty acid having a carbon number of 16 or more may be a saturated and / or unsaturated fatty acid.

[0158] Examples of the saturated fatty acid include palmitic acid (hexadecanoic acid, CH 3 (CH 2 ) 14 COOH), margaric acid (heptadecanoic acid, CH 3 (CH 2 ) 15 COOH), stearic acid (octadecanoic acid, CH 3 (CH 2 ) 16 COOH), nonadecylic acid (nonadecanoic acid, CH 3 (CH 2 ) 17 COOH), or arachidic acid (eicosanoic acid, CH 3 (CH 2 ) 18 COOH). According to certain embodiments, the saturated fatty acid is selected from the group consisting of palmitic acid (hexadecanoic acid, CH 3 (CH 2 ) 14 COOH), margaric acid (heptadecanoic acid, CH 3 (CH 2 ) 15 COOH), stearic acid (octadecanoic acid, CH 3 (CH 2 ) 16 COOH), nonadecylic acid (nonadecanoic acid, CH 3 (CH 2 ) 17 COOH), arachidic acid (eicosanoic acid, CH 3 (CH 2 ) 18 COOH), or a combination thereof.

[0159] However, the types of saturated fatty acids that can be used are not limited to the aforementioned examples. In some embodiments, the fatty acid is selected from the group consisting of palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, palmitoleic acid, oleic acid, linoleic acid, and arachidonic acid.

[0160] Examples of the unsaturated fatty acid include palmitoleic acid (CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH), oleic acid (CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH), linoleic acid (C 18 H 32 O 2 ), arachidonic acid (C 20 H 32 O 2 ), and the like. In certain embodiments, the unsaturated fatty acid is selected from the group consisting of palmitoleic acid (CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH), oleic acid (CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH), linoleic acid (C 18 H 32 O 2 ), arachidonic acid (C 20 H 32 O 2 ), or a combination thereof. However, the types of unsaturated fatty acids that can be used are not limited to the aforementioned examples.

[0161] Although not particularly limited, the upper limit on the carbon number of the fatty acid having a carbon number of 16 or more may be, for example, 40 or less, 36 or less, 32 or less, 28 or less, 24 or less, or 20 or less.

[0162] In some embodiments of the present disclosure, an esterification product of sorbitan and oleic acid (e.g., sorbitan monooleate) may be used as the component (b). However, the type of component (b) that can be used is not limited to the foregoing.

[0163] The content of component (b) may be controlled in consideration of the intended function of the component (b) and that of the emulsion.

[0164] In some embodiments, the emulsion may include, per 100 parts by weight of component (a), which is an esterification product of a fatty acid having a carbon number of 16 or more and an aliphatic monohydric alcohol, 20 to 60 parts by weight of component (b), which is an esterification product of sorbitan and a fatty acid having a carbon number of 16 or more.

[0165] Specifically, the content of component (b) in the emulsion of the present disclosure may be, per 100 parts by weight of component (a), 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. Further, the upper limit of the content of component (b), per 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. Meeting the aforementioned content ranges may impart hydrophobicity to the surface of the emulsion-treated lyocell multifilament or the surface of the lyocell tow.

[0166] In some embodiments, the emulsion may include 40 to 80 wt% of component (a), which is an esterification product of a fatty acid having a carbon number of 16 or more and an aliphatic monohydric alcohol, based on 100 wt% of the total weight of the emulsion. Specifically, based on 100 wt% of the total weight of the emulsion, the content of component (a) may be 45 wt% or more, 50 wt% or more, 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, or 75 wt% or more. Further, the 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.

[0167] In some embodiments, the emulsion may include component (a) in an excess amount.

[0168] In some embodiments, the emulsion may include 15 to 55 wt% of component (b), which is an esterification product of sorbitan and a fatty acid having a carbon number of 16 or more, based on 100 wt% of the total weight of the emulsion. Specifically, based on 100 wt% of the total weight of the emulsion, 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. Furthermore, the 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.

[0169] In some embodiments, the emulsion may further include water. A small amount of water may aid in emulsification.

[0170] The water content may not be particularly limited and may correspond to a residual amount obtained by subtracting the total contents of components (a) and (b) from 100 wt% of the emulsion. The water content included in the emulsion (i.e., a residual amount obtained by subtracting the total content of the other 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. Further, the lower limit of the water content 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]

[0171] The present disclosure relates to a method of preparing a lyocell material. Through this method, a lyocell material may be prepared, which may be used in a smoking article.

[0172] Specifically, the method of preparing the lyocell material includes: preparing a lyocell dope; spinning the lyocell dope; coagulating; obtaining a multifilament; water-washing; treating with an emulsion; and imparting crimp. Additionally, the method of preparing the lyocell material may further include: treating with a binder; and other processes (steps). Crimp imparting can be referred to crimping or imparting crimp.

[0173] The process of treating with an emulsion may be performed before the crimp-imparting process, may be performed after the crimp-imparting process, or may be performed before and after the crimp-imparting process.

[0174] The process of treating with an emulsion may each independently be performed, by a method of, for example, spraying the lyocell multifilament with the emulsion of the aforementioned composition, or immersing the lyocell multifilament in the emulsion. The process of treating with an emulsion may be performed such that the content of the emulsion in the lyocell material (e.g., OPU (wt%)) satisfies a predetermined range.

[0175] The crimp-imparting process may be performed, for example, by applying steam and / or pressure to the lyocell multifilament.

[0176] The method of preparing a lyocell material according to an embodiment of the present disclosure, which includes the process of treating with an emulsion and the crimp-imparting process, is described in greater detail below. The method of the present disclosure may be carried out by including one or more processes described below.[Lyocell Dope]

[0177] According to an embodiment, a lyocell dope is provided, including NMMO and ground pulp dissolved in the NMMO, wherein the ground pulp exhibits a particle size span of 1.4 to 4.0, with the particle size span calculated according to Formula 1 below: Span = D 90 − D 10 / D 50

[0178] In Formula 1, D 10 is a particle size of the ground pulp at 10 % cumulative distribution, D 90 is a particle size of the ground pulp at 90 % cumulative distribution, and D 50 is a particle size of the ground pulp at 50 % cumulative distribution.

[0179] The cumulative distribution may be a value calculated by accumulating from ground pulp having small particle sizes to ground pulp having large particle sizes. The particle size of the ground pulp is measured using laser diffraction, for example, using a particle size analyzer from MALVEN (model name: Mastersizer 3000, operated in a dry analysis).

[0180] In one embodiment, the ground pulp may be subject to a pre-treatment step by drying in an oven, preferably at 100°C for about 6 hours. The pre-treatment step can be carried out in order to prevent agglomeration of the ground pulp caused by residual moisture.

[0181] The particle size analyzer is based on the principle of laser diffraction. In particular, the analyzer irradiates the sample with a laser beam, collects the light scattered by the particles using a detector, and interprets the resulting scattering pattern to calculate the particle size distribution. This method utilizes the principle that the scattering angle and intensity vary according to the particle size of the sample, thereby allowing quantification of the particle size distribution.

[0182] The average particle sizes may be expressed as the volume-weighted mean diameter, D[4,3]. Since D[4,3] is calculated by assigning weights proportional to the particle volume, it is suitable for representing the overall ground pulp. Furthermore, because of its strong correlation with physical behavior and quality characteristics in actual manufacturing processes, D[4,3] may be employed as the representative index of the average particle size in the present analysis.

[0183] The lyocell material according to some embodiments is obtained by spinning a lyocell dope with controlled properties. Specifically, the lyocell dope contains ground pulp with a span value controlled to 4.0 or below. By controlling the span value to 4.0 or below, uniformity of the ground pulp may be ensured and the ground pulp may be completely dissolved in NMMO.

[0184] As a result, the spinnability of the lyocell dope may be improved, and the uniformity of lyocell monofilaments and lyocell multifilaments obtained by spinning the lyocell dope may be enhanced. Furthermore, by improving uniformity of the lyocell multifilaments, processability of the lyocell multifilaments may be improved, and uniformity and processability of lyocell materials including the lyocell multifilaments may be improved.

[0185] In some embodiments, the particle size span value may be 1.4 or more.

[0186] Specifically, the upper limit of the particle size span value may be 4.0 or less, 3.9 or less, 3.8 or less, 3.7 or less, 3.6 or less, 3.5 or less, 3.4 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, or 2.0 or less. By controlling the upper limit of the span value, the uniformity of ground pulp particles may be further improved. As a result, the solubility of ground pulp particles may be further increased, and the uniformity of lyocell dope containing the pulp may be further improved.

[0187] In addition, the lower limit of the particle size span value may be 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, 2.5 or more, 2.6 or more, or 2.7 or more. By increasing the lower limit of the span value, the flow rate deviation of ground pulp can be maintained below 10.0 %, and the pressure deviation of lyocell dope containing the pulp can be maintained below 15.0 %.

[0188] Specifically, when the span value of ground pulp is less than 1.4, the flow rate deviation of ground pulp may exceed 15.0 %, and the pressure deviation of lyocell dope containing the pulp may exceed 20.0 %. As a result, the solubility of the ground pulp and the spinning stability of lyocell dope may appear poor.

[0189] Furthermore, in terms of improving uniformity and processability of lyocell materials, the particle size span value may be 1.4 to 4.0, 1.5 to 4.0, 1.6 to 4.0, 1.7 to 4.0, 1.8 to 4.0, 1.9 to 4.0, 2.0 to 4.0, 2.1 to 4.0, 2.2 to 4.0, 2.3 to 4.0, 2.4 to 4.0, 2.5 to 4.0, 2.6 to 4.0, 2.7 to 4.0, 2.8 to 4.0, 2.9 to 4.0, 3.0 to 4.0, 3.1 to 3.0, 3.2 to 4.0, 3.3 to 4.0, 3.4 to 4.0, 3.5 to 4.0, 3.6 to 4.0, 3.7 to 4.0, 3.8 to 4.0, 3.9 to 4.0, 1.4 to 3.9, 1.4 to 3.8, 1.4 to 3.7, 1.4 to 3.6, 1.4 to 3.5, 1.4 to 3.4, 1.4 to 3.3, 1.4 to 3.2, 1.4 to 3.1, 1.4 to 3.0, 1.4 to 2.9, 1.4 to 2.8, 1.4 to 2.7, 1.4 to 2.6, 1.4 to 2.5, 1.4 to 2.4, 1.4 to 2.3, 1.4 to 2.2, 1.4 to 2.1, 1.4 to 2.0, 1.4 to 1.9, 1.4 to 1.8, 1.4 to 1.7, 1.4 to 1.6, or 1.4 to 1.5.

[0190] In some embodiments, the particle size span value may be a value measured before ground pulp is dissolved in NMMO. Similarly, D 90 , D 50 , and D 10 of the ground pulp may also be values measured before the ground pulp is dissolved.

[0191] In some embodiments, D 90 of ground pulp may be 800 µm or less, and D 90 of ground pulp may be 150 µm or more. When the D 90 of ground pulp exceeds 800 µm, undissolved ground pulp may be included in the lyocell dope, and uniformity of the lyocell dope may be degraded.

[0192] Specifically, the upper limit of D 90 of ground pulp may be 800 µm or less, 750 µm or less, 700 µm or less, 650 µm or less, 600 µm or less, 550 µm or less, 500 µm or less, 450 µm or less, 400 µm or less, 350 µm or less, 300 µm or less, or 250 µm or less. By lowering the upper limit of D 90 for pulp, uniformity of ground pulp particles can be further improved. As a result, uniformity of lyocell dope can be further enhanced.

[0193] Additionally, the lower limit of D 90 of ground pulp may be 150 µm or more, 200 µm or more, 250 µm or more, 300 µm or more, 350 µm or more, 400 µm or more, 450 µm or more, 500 µm or more, 550 µm or more, 600 µm or more, or 650 µm or more.

[0194] In some embodiments, the ground pulp may have an average particle size of 400 µm or less, and the ground pulp may have an average particle size of 80 µm or more. When the average particle size of ground pulp exceeds 400 µm, undissolved ground pulp may be included in lyocell dope, and uniformity of lyocell dope may be degraded.

[0195] Specifically, the average particle size of ground pulp may be 400 µm or less, 375 µm or less, 350 µm or less, 325 µm or less, 300 µm or less, 275 µm or less, 250 µm or less, 225 µm or less, 200 µm or less, 175 µm or less, or 150 µm or less. By lowering the upper limit of average particle size of ground pulp, solubility of ground pulp particles may be further improved. As a result, the number of undissolved ground pulp particles remaining in lyocell dope can be reduced, and the spinnability of lyocell dope can be further enhanced.

[0196] Additionally, the lower limit of average particle size of ground pulp may be 80 µm or more, 100 µm or more, 125 µm or more, 150 µm or more, 175 µm or more, 80 µm or more, 225 µm or more, 250 µm or more, 300 µm or more, or 325 µm or more. By increasing the lower limit of average particle size of ground pulp, the flow rate deviation of ground pulp can be maintained below 10.0 %, and the pressure deviation of lyocell dope containing the pulp can be maintained below 15.0 %.

[0197] Specifically, when the average particle size of ground pulp is less than 80 µm, the flow rate deviation of ground pulp may exceed 15.0 %, and the pressure deviation of lyocell dope containing the pulp may exceed 20.0 %. As a result, the solubility of ground pulp and spinning stability of lyocell dope may be poor.

[0198] In some embodiments, the D 10 of ground pulp may be 120 µm or less, and the D 10 of ground pulp may be 10 µm or more. Specifically, the D 10 of ground pulp may be 110 µm or less, 100 µm or less, 90 µm or less, 80 µm or less, 70 µm or less, 60 µm or less, 50 µm or less, 40 µm or less, or 30 µm or less. The D 10 of ground pulp may be 20 µm or more, 30 µm or more, 40 µm or more, 50 µm or more, 60 µm or more, 70 µm or more, 80 µm or more, 90 µm or more, 100 µm or more, or 110 µm or more.

[0199] In some embodiments, all particle sizes of ground pulp may be 900 µm or less. As used in this application, all particle size refers to the particle size of all particles included in the ground pulp. When ground pulp having a particle size of 900 µm or more is included, undissolved ground pulp from the lyocell dope may be observed even with the naked eye. As described above, undissolved ground pulp can degrade the uniformity and spinnability of lyocell dope.

[0200] Additionally, all particle sizes of ground pulp may be 10 µm or more.

[0201] In some embodiments, the flow rate deviation of the ground pulp may be 10.0 % or less. When the flow rate deviation of ground pulp exceeds 10.0 %, clumping of ground pulp may be found in the lyocell dope. As a result, the stability of ground pulp feeding may be compromised, and the processability during preparation of lyocell dope may be degraded. Specifically, the upper limit of flow rate deviation of ground pulp may be 9.5 % or less, 9.0 % or less, 8.5 % or less, 8.0 % or less, 7.5 % or less, 7.0 % or less, 6.5 % or less, 6.0 % or less, 5.5 % or less, 5.0 % or less, 4.5 % or less, 4.0 % or less, 3.5 % or less, or 3.0 % or less.

[0202] In some embodiments, the flow rate deviation of ground pulp may be 2.0 % or more.

[0203] In some embodiments, the content of ground pulp in the lyocell dope may be 5 to 15 wt% based on 100 wt% of the total dope weight. When the content of ground pulp is excessively low, achieving the characteristics of lyocell fiber is difficult, and when the content exceeds the above range, dissolution in solvent is difficult. Considering the foregoing, the content of ground pulp in the lyocell dope may be 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, or 10 wt% or more, and the upper limit may be, for example, 14 wt% or less, 13 wt% or less, 12 wt% or less, 11 wt% or less, 10 wt% or less, or 9 wt% or less.

[0204] In some embodiments, the lyocell dope may include an NMMO aqueous solution. The aqueous solution may include, for example, 80 to 95 parts by weight of NMMO and 5 to 20 parts by weight of H 2 O, considering the degree of cellulose dissolution, process temperature, and the like.

[0205] In some embodiments, the ground pulp may have an alpha cellulose content of 85 to 97 wt% based on 100 wt% of the total ground pulp.

[0206] In some embodiments, the ground pulp may have a hemicellulose content of 3 wt% to 15 wt% based on 100 wt% of the total ground pulp. By controlling the hemicellulose content within the aforementioned range, stable physical properties of lyocell materials (e.g., hardness or draw resistance) and processability can be more easily secured.

[0207] Additionally, in an embodiment of the present disclosure, the degree of polymerization (DPw) of the cellulose may be 600 to 1,700. The degree of polymerization refers to the number of repeating units and / or monomeric units of the components (cellulose, hemicellulose, etc.) contained in the cellulose pulp. The polymerization degree (DPw) is given by DPw = Mn / M0 wherein Mn is the number-average molecular weight of the macromolecule or polymer or oligomer molecule and M0 is the molecular weight of the monomeric unit.<(a) Lyocell Dope Preparation Process (Preparing a lyocell dope)>

[0208] This process is a process of preparing a lyocell dope including ground pulp (or cellulose) and NMMO.

[0209] Commercialized cellulose acetate filters are identified as a major cause of microplastic generation. However, lyocell materials generate no pollutants during their production process, as the amine oxide-based solvents used in lyocell fiber manufacturing are recyclable and biodegradable upon disposal. Furthermore, lyocell materials (e.g., lyocell tow) biodegrade and are removed in a relatively short time, making lyocell more environmentally friendly than cellulose acetate.

[0210] The process of preparing a lyocell dope may include: obtaining ground pulp (a1); transporting ground pulp (a2); and mixing ground pulp with NMMO (a3).

[0211] In some embodiments, the process of obtaining ground pulp (a1) may be a process of feeding raw pulp into a grinder equipped with a mesh filter and grinding the pulp. Additionally, the mesh size of the mesh filter may be adjusted to control the particle size of ground pulp. The type of raw pulp is not particularly limited.

[0212] Furthermore, in some embodiments, the particle size span value of ground pulp included in the lyocell dope may be 4.0 or less. The particle size span value may be calculated according to Formula 1 below. Span = D 90 − D 10 / D 50

[0213] In Formula 1, D 10 is a particle size of the ground pulp at 10 % cumulative distribution, D 90 is a particle size of the ground pulp at 90 % cumulative distribution, and D 50 is a particle size of the ground pulp at 50 % cumulative distribution. The particle size of the ground pulp is measured using laser diffraction, for example, using a particle size analyzer from MALVEN (model name: Mastersizer 3000).

[0214] In some embodiments, the D 90 of ground pulp may be 800 µm or less, and the D 90 of ground pulp may be 150 µm or more.

[0215] In some embodiments, the D 50 of ground pulp may be 400 µm or less, and the average particle size of ground pulp may be 80 µm or more.

[0216] In some embodiments, the D 10 of ground pulp may be 120 µm or less, and the D 10 of ground pulp may be 10 µm or more.

[0217] In some embodiments, the ground pulp may not include ground pulp having a particle size of 900 µm or more, and the ground pulp may not include ground pulp having a particle size of 10 µm or less.

[0218] In some embodiments, the process of transporting ground pulp (a2) may be a process of transporting ground pulp through a transport tube. The ground pulp may be transported in powder form, and flow rate deviation may be measured during the transport process.

[0219] Furthermore, in some embodiments, the flow rate deviation of ground pulp may be 10.0 % or less. When the flow rate deviation of ground pulp exceeds 10.0 %, clumping of ground pulp may be found in the lyocell dope. As a result, the stability of ground pulp feeding may be compromised, and the processability during preparation of lyocell dope may be degraded. Specifically, the upper limit of flow rate deviation of ground pulp may be 9.5 % or less, 9.0 % or less, 8.5 % or less, 8.0 % or less, 7.5 % or less, 7.0 % or less, 6.5 % or less, 6.0 % or less, 5.5 % or less, 5.0 % or less, 4.5 % or less, 4.0 % or less, 3.5 % or less, or 3.0 % or less.

[0220] For determining the flow rate deviation, an hourly flow rate of ground pulp transported by a loss-in-weight feeder was measured. Based on the measured hourly flow rate, the average flow rate, minimum flow rate, and maximum flow rate are calculated. The average flow rate is defined as the flow rate per unit time. Based on the calculated values, the flow rate deviation (%) was calculated according to Formula 3 below:

[0221] In some embodiments, the process of mixing ground pulp with NMMO (a3) may be a process of mixing ground pulp with NMMO under stirring conditions. The stirring means and stirring conditions are not particularly limited.

[0222] In some embodiments, the content of ground pulp in the lyocell dope may be 5 to 15 parts by weight based on 100 parts by weight of the total lyocell dope.

[0223] When the content of ground pulp is excessively low, achieving the characteristics of lyocell fibers may be difficult, and when the content exceeds the above range, dissolution in solvent may be difficult. In consideration of the foregoing, the content of ground pulp in the lyocell dope may be, for example, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, or 10 parts by weight or more, and may have an upper limit of, for example, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 parts by weight or less, 10 parts by weight or less, or 9 parts by weight or less.

[0224] The lyocell dope according to some embodiments may further include water (H 2 O). A liquid in which NMMO and water are mixed may be referred to as an NMMO aqueous solution.

[0225] In some embodiments, the weight of the NMMO aqueous solution may be 85 parts by weight to 95 parts by weight relative to 100 parts by weight of the total lyocell dope.

[0226] In some embodiments, the NMMO aqueous solution may include 80 to 95 parts by weight of NMMO and 5 to 20 parts by weight of H 2 O.

[0227] Additionally, In some embodiments, the ground pulp or cellulose may have an alpha cellulose content of 85 to 97 wt% based on 100 wt% of the total ground pulp.

[0228] In some embodiments, the ground pulp or cellulose may have a hemicellulose content of 3 wt% to 15 wt% based on 100 wt% of the total ground pulp. By controlling the hemicellulose content within the aforementioned range, stable physical properties of lyocell materials (e.g., hardness or draw resistance implementation) and processability may be more easily secured.

[0229] Additionally, the degree of polymerization (DPw) of the cellulose may be 600 to 1,700. The degree of polymerization is defined as described above.<(b) Lyocell Dope Spinning Process (spinning the lyocell dope)>

[0230] This process is a process of spinning the prepared lyocell dope. In this spinning process, the form of the spinneret used for spinning lyocell dope is not particularly limited. For example, a donut-shaped spinneret may be used.

[0231] The nozzle temperature of the spinneret, specifically the spinning temperature, may be appropriately selected by those skilled in the art. Considering that the viscosity of the lyocell dope varies with spinning temperature and the extrusion may not proceed well, the spinning may be carried out, for example, at a spinning temperature in the range of 100 °C to 120 °C or less, or 100 °C to 110 °C or less.

[0232] In some embodiments, the pressure deviation of lyocell dope may be 15 % or less. When the pressure deviation of lyocell dope exceeds 15 %, the variation range of pressure applied to the spinneret during spinning of lyocell dope becomes excessively large, and as a result, the uniformity of the spun lyocell monofilaments and lyocell multifilaments may be degraded. Specifically, the upper limit of pressure deviation for lyocell dope may be 15 % or less, 14.5 % or less, 14 % or less, 13.5 % or less, 13 % or less, 12.5 % or less, 12 % or less, 11.5 % or less, 11 % or less, 10.5 % or less, 10 % or less, 9.5 % or less, 9.0 % or less, 8.5 % or less, 8.0 % or less, 7.5 % or less, 7.0 % or less, 6.5 % or less, 6.0 % or less, 5.5 % or less, 5.0 % or less, 4.5 % or less, or 4.0 % or less. The pressure deviation (%) is calculated according to Formula 4 below:

[0233] In some embodiments, the process of spinning the lyocell dope may be performed under controlled spinning conditions such that the single filament fineness of filaments may be 1.5 denier to 8.0 denier or less. For example, one or more spinning conditions among the extrusion rate and spinning speed of the lyocell dope may be appropriately controlled so that the single filament fineness of filaments included in the lyocell material satisfies 1.5 to 8.0 denier. Here, the single filament fineness refers to the fineness of a single monofilament separated from a multifilament.

[0234] Specifically, the single filament fineness of filaments may be, for example, 7.5 denier or less, 7.0 denier or less, 6.5 denier or less, 6.0 denier or less, 5.5 denier or less, 5.0 denier or less, 4.5 denier or less, 3.5 denier or less, 3.0 denier or less, 2.5 denier or less, or 2.0 denier or less. Furthermore, the lower limit of the single filament fineness of filaments may be, for example, 2.0 denier or more, 2.5 denier or more, 3.0 denier or more, 3.5 denier or more, 4.0 denier or more, 4.5 denier or more, 5.0 denier or more, 5.5 denier or more, 6.0 denier or more, 6.5 denier or more, or 7.0 denier or more. Meeting the aforementioned ranges may be more advantageous for ensuring stable draw resistance implementation in the smoking article filter and securing process reliability.

[0235] The lyocell dope extruded through the spinneret may undergo a coagulation process described below.<(c) Coagulating Process and Process of Obtaining Multifilament (Coagulating and obtaining a lyocell multifilament)>

[0236] In this process, the spun lyocell dope may be coagulated, and lyocell multifilaments may be obtained.

[0237] For the coagulation, a method in which the lyocell dope contacts air and / or coagulation liquid may be used.

[0238] In some embodiments, the coagulation may include: a first coagulation process of supplying cooled air to the spun lyocell dope; and a second coagulation process of introducing the lyocell dope having undergone the first coagulation into coagulation liquid for coagulation.

[0239] According to this coagulation method, the lyocell dope extruded from the spinneret may undergo a first coagulation in the space between the spinneret and a coagulation bath (air-gap section). In this air gap section, for example, cooling air may be supplied from inside to outside of the spinneret from an air cooling section located within the spinneret. In addition, the first coagulation may be carried out using so-called air-quenching methods or means known in the art.

[0240] In some embodiments, the upper temperature limit of cooling air used for the first coagulation may be, for example, 15 °C or less. Specifically, the cooling air may be air at temperatures of 14 °C or less, 13 °C or less, 12 °C or less, 11 °C or less, or 10 °C or less. When the temperature exceeds the aforementioned range, coagulation of lyocell dope by air is insufficient, and spinning-related processability is poor.

[0241] The lower limit of the cooling air may be determined in consideration of spinning processability and / or cross-sectional uniformity of filaments. For example, when the temperature of cooling air is less than 4 °C, the surface of the spinneret cools, the surface of filaments becomes non-uniform, and spinning processability also deteriorates. In light of the foregoing, the cooling air may be 5 °C or more, 6 °C or more, 7 °C or more, 8 °C or more, or 9 °C or more.

[0242] The degree to which the cooling air is supplied may be controlled in consideration of sufficient coagulation, spinning processability, and the effects on filament properties. For example, the cooling air may be supplied at an airflow rate of 70 to 400 Nm 3< / h to the extruded lyocell dope. More specifically, the airflow rate may be 100 Nm 3< / h or more, 150 Nm 3< / h or more, 200 Nm 3< / h or more, or 250 Nm 3< / h or more, and the upper limit of the airflow rate may be, for example, 350 Nm 3< / h or less, 300 Nm 3< / h or less, 250 Nm 3< / h or less, 200 Nm 3< / h or less, or 150 Nm 3< / h or less.

[0243] After the first coagulation as described above, the cooled lyocell dope may be supplied to a coagulation bath or bath containing coagulation liquid (second coagulation). For suitable progress of the coagulation, the temperature of the coagulation liquid may, for example, be 30 °C or less, or 25 °C or less. In addition, the temperature of the coagulation liquid may be at least 10 °C, at least 15 °C, or at least 20 °C. By maintaining the temperature in the aforementioned range, the coagulation rate may be appropriately maintained.

[0244] The type of coagulation liquid for the second coagulation is not particularly limited. For example, the coagulation liquid may include one or more of water and NMMO.

[0245] Although not particularly limited, when the coagulation liquid includes water and NMMO, the content of water in the coagulation liquid may be 60 to 90 wt%, and the content of NMMO may be 10 to 40 wt%. Alternatively, the coagulation liquid may include 70 to 80 wt% of water and 20 to 30 wt% of NMMO. The concentration of such coagulation liquid may be controlled to be maintained during the manufacturing process using sensors or the like.<(d) Water-washing Process (water-washing)>

[0246] If necessary, after the process involving coagulation and multifilament described above, the lyocell multifilament may be water-washed. Through this water-washing, any residual NMMO and / or other impurities within the filament may be removed.

[0247] The method of performing the water-washing is not particularly limited. For example, the water-washing may be carried out by introducing the coagulated lyocell multifilament into a washing bath using a take-up roller. Alternatively, the water-washing may be performed by spraying a washing liquid onto the multifilaments as they are conveyed to the next process by a take-up roller.

[0248] The components of the washing liquid are not particularly limited. For example, the washing liquid may include water, and may further include other known additives.

[0249] Additionally, in consideration of reuse after water-washing, the washing liquid may be regulated to a temperature of 100 °C or less.<(e) Process of Treating with Emulsion (treating with an emulsion)>

[0250] If necessary, a process of applying an emulsion to lyocell multifilaments may be performed. This process is a process of applying an emulsion of the aforementioned components to the surface of the filaments. The emulsion treatment may reduce friction exerted on the filament and enable good crimp formation in the crimp-imparting process described below. When the emulsion treatment is to be carried out two or more times as described below, they may be referred to as first emulsion treatment and second emulsion treatment according to their sequence.

[0251] Although not particularly limited, the emulsion treatment may be performed by immersing lyocell multifilaments in a bath filled with emulsion so that the lyocell multifilaments are fully submerged. Alternatively, the emulsion treatment may be carried out by spraying emulsion liquid during the process of moving to the next process by take-up rollers.

[0252] To ensure that the amount of emulsion applied to the lyocell multifilaments after emulsion treatment as described above is uniform, a process may be additionally performed in which rolls positioned before and / or after the emulsion treatment process squeeze out emulsion from the surface of the lyocell multifilaments.

[0253] In some embodiments, the emulsion treatment may be performed such that the emulsion content (OPU: oil pick up ratio (wt%)) satisfies 1.0 wt% or more based on 100 wt% of the lyocell multifilaments that have undergone at least one emulsion treatment. In this context, the lyocell multifilaments that have undergone at least one emulsion treatment refer to, for example, lyocell multifilaments to which first emulsion treatment has been applied, lyocell multifilaments to which both first and second emulsion treatments (see below for details) have been applied, or lyocell multifilaments to which the aforementioned emulsion treatment(s) as well as binders described below have been applied. Further, the lyocell multifilaments that have undergone the emulsion and / or binder treatment as described above may be one that has been crimped.

[0254] Specifically, the emulsion content in the lyocell multifilaments that have undergone at least one emulsion treatment 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, 3.0 wt% or more, and specifically may be 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, based on the total weight of the at least one emulsion-treated lyocell multifilaments. In addition, the upper limit of the emulsion content 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 7.6 wt% or less, based on the total weight of the at least one emulsion-treated lyocell multifilaments. Here, the content may refer to the dry weight after evaporation of solvents (e.g., water) or liquid components that may be included in the emulsion.

[0255] When the emulsion having the aforementioned composition is treated within the content range, the hydrophilic characteristics of the lyocell material can be supplemented.

[0256] In some embodiments, drying of the emulsion may be performed after the emulsion treatment as described above.

[0257] In some embodiments of the present disclosure, one or more of the aforementioned processes may be controlled such that the single filament fineness of the filaments constituting the lyocell multifilaments may be 1.67 dtex to 8.89 dtex (1.5 to 8.0 denier). The single filament fineness of the filaments refers to the fineness of a single monofilament separated from the multifilament, as described above.

[0258] Specifically, the single filament fineness of the filaments 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). Additionally, the lower limit of the single filament fineness of the filaments 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. Meeting the aforementioned range may be more advantageous for ensuring stable draw resistance implementation in the smoking article filter and securing process reliability.

[0259] Although not particularly limited, the process controlled to secure the aforementioned single filament fineness range may be the aforementioned spinning process. Alternatively, all of the aforementioned spinning, coagulation, washing, and emulsion treatment processes may be controlled to secure the aforementioned single filament fineness range.<(f) Crimp-Imparting Process (crimp imparting or imparting crimp)>

[0260] This crimp-imparting process is a process that enables obtaining crimped multifilaments, preferably crimped tow, by applying pressure to the emulsion-treated lyocell multifilament through steam and / or press rollers. The crimp-imparting process may be referred to as a crimping process.

[0261] Through crimping, the lyocell multifilament may be imparted with waves, and the fiber may acquire a bulky characteristic. Crimping may be performed using known crimp machines such as those including a stuffer box and / or steam box, and usable crimp machines are not particularly limited as long as they can apply one or more of the pressures described below.

[0262] In some embodiments, the crimp-imparting process may be carried out by first supplying steam to the lyocell multifilament to preheat and swell the lyocell multifilament, followed by pressing the lyocell multifilament with a press roller to form wrinkles in the lyocell multifilament. In this case, a steam box may be used for steam supply, and such a steam box may be positioned upstream of the crimp machine.

[0263] In some embodiments, the crimp-imparting process may be carried out in such a way that the pressing of the lyocell multifilament with a press roller and the supply of steam occur simultaneously.

[0264] In some embodiments, the crimp-imparting process may be performed by first supplying steam to the lyocell multifilament to preheat and swell the lyocell multifilament, followed by simultaneously pressing the lyocell multifilament with press rollers and applying steam.

[0265] In some embodiments, the crimp-imparting process may be performed while applying steam at 0.98 to 19.61 N / cm 2< (0.1 to 2.0 kgf / cm 2< ) to each lyocell multifilament before feeding into the crimp machine (in particular, press rollers).

[0266] For example, steam of 1.96 N / cm 2< (0.2 kgf / cm 2< ) or more, 2.94 N / cm 2< (0.3 kgf / cm 2< ) or more, 3.92 N / cm 2< (0.4 kgf / cm 2< ) or more, 4.90 N / cm 2< (0.5 kgf / cm 2< ) or more, or 5.88 N / cm 2< (0.6 kgf / cm 2< ) or more may be provided by a steam box. In addition, steam of 14.71 N / cm 2< (1.5 kgf / cm 2< ) or less, 13.73 N / cm 2< (1.4 kgf / cm 2< ) or less, 12.75 N / cm 2< (1.3 kgf / cm 2< ) or less, 11.77 N / cm 2< (1.2 kgf / cm 2< ) or less, 10.79 N / cm 2< (1.1 kgf / cm 2< ) or less, or 9.81 N / cm 2< (1.0 kgf / cm 2< ) or less may be provided. When the steam supply amount or pressure is below the aforementioned range, crimps may not be formed smoothly. When the steam supply amount or pressure exceeds the aforementioned range, the filaments may become overly flexible in the crimp machine, resulting in excessive crimp that prevents the filaments from passing through the crimp machine.

[0267] In some embodiments, the crimp-imparting process may be performed by pressing the lyocell multifilament with a press roller to form wrinkles in the lyocell multifilament. In addition, the steam supply may not be performed before the pressing, the steam supply may not be performed simultaneously with the pressing, and the steam supply may not be performed both before and simultaneously with the pressing.

[0268] In some embodiments, the crimp-imparting process may be performed by applying a pressure of 14.71 to 39.23 N / cm 2< (1.5 to 4.0 kgf / cm 2< ) independently to each lyocell multifilament fed into the crimp machine using a press roller.

[0269] For example, a pressure of 15.69 N / cm 2< (1.6 kgf / cm 2< ) or more, 16.67 N / cm 2< (1.7 kgf / cm 2< ) or more, 17.65 N / cm 2< (1.8 kgf / cm 2< ) or more, 18.63 N / cm 2< (1.9 kgf / cm 2< ) or more, 19.61 N / cm 2< (2.0 kgf / cm 2< ) or more, 20.60 N / cm 2< (2.1 kgf / cm 2< ) or more, 21.58 N / cm 2< (2.2 kgf / cm 2< ) or more, 22.56 N / cm 2< (2.3 kgf / cm 2< ) or more, 23.54 N / cm 2< (2.4 kgf / cm 2< ) or more, or 24.52 N / cm 2< (2.5 kgf / cm 2< ) or more may be applied to the lyocell multifilament through a press roller. In addition, a pressure of 38.25 N / cm 2< (3.9 kgf / cm 2< ) or less, 37.27 N / cm 2< (3.8 kgf / cm 2< ) or less, 36.29 N / cm 2< (3.7 kgf / cm 2< ) or less, 35.31 N / cm 2< (3.6 kgf / cm 2< ) or less, 34.33 N / cm 2< (3.5 kgf / cm 2< ) or less, 33.35 N / cm 2< (3.4 kgf / cm 2< ) or less, 32.37 N / cm 2< (3.3 kgf / cm 2< ) or less, 31.39 N / cm 2< (3.2 kgf / cm 2< ) or less, 30.41 N / cm 2< (3.1 kgf / cm 2< ) or less, 29.42 N / cm 2< (3.0 kgf / cm 2< ) or less, 28.44 N / cm 2< (2.9 kgf / cm 2< ) or less, 27.46 N / cm 2< (2.8 kgf / cm 2< ) or less, 26.48 N / cm 2< (2.7 kgf / cm 2< ) or less, 25.50 N / cm 2< (2.6 kgf / cm 2< ) or less, or 24.52 N / cm 2< (2.5 kgf / cm 2< ) or less may be applied by a press roller.

[0270] If the pressure by the press roller is below the aforementioned range, the intended number of crimps may not be fully formed. If the roller pressure exceeds the aforementioned range, the pressing force may be excessively high, preventing the filaments from entering the crimp machine smoothly or passing through the stuffer box. Wrinkles may be formed in the lyocell multifilament by the press roller providing the aforementioned pressure.

[0271] In some embodiments, a pressure of 0.98 to 19.61 N / cm 2< (0.1 to 2 kgf / cm 2< ) may be independently applied to each lyocell multifilament using an upper plate. In addition, the upper plate may apply pressure to each lyocell multifilament while or after each lyocell multifilament passes through the press roller.

[0272] For example, the pressure applied by the upper plate may be 1.96 N / cm 2< (0.2 kgf / cm 2< ) or more, 2.94 N / cm 2< (0.3 kgf / cm 2< ) or more, 3.92 N / cm 2< (0.4 kgf / cm 2< ) or more, or 4.90 N / cm 2< (0.5 kgf / cm 2< ) or more. Additionally, pressure of 14.71 N / cm 2< (1.5 kgf / cm 2< ) or less, 13.73 N / cm 2< (1.4 kgf / cm 2< ) or less, 12.75 N / cm 2< (1.3 kgf / cm 2< ) or less, 11.77 N / cm 2< (1.2 kgf / cm 2< ) or less, 10.79 N / cm 2< (1.1 kgf / cm 2< ) or less, or 9.81 N / cm 2< (1.0 kgf / cm 2< ) or less may be applied by the upper plate. Furthermore, if the pressure of the upper plate, which moves up and down to provide uniform crimping after passing through the press rollers, is less than 0.98 N / cm 2< (0.1 kgf / cm 2< ), the upper plate fails to be fixed due to the pressure inside the stuffer box, causing tow to remain in the stuffer box for an extended time and preventing process continuity. If the pressure of the upper plate exceeds 19.61 N / cm 2< (2 kgf / cm 2< ), steam fails to be smoothly discharged from the stuffer box, causing irregular crimp formation.

[0273] In some embodiments, the crimp-imparting process may employ a doctor blade that applies a predetermined pressure to the lyocell multifilament. The doctor blade contributes to controlling the number of crimps by adjusting the residence time of filaments fed into the crimper stuffer box. Such a doctor blade may be positioned, for example, in the travel path of the lyocell multifilament discharged from the roller pressing point after being pressed by the aforementioned roller.

[0274] In some embodiments, the crimp-imparting process may be performed while independently applying pressure of 0.98 to 19.61 N / cm 2< (0.1 to 2.0 kgf / cm 2< ) to each lyocell multifilament that has passed through the rollers of the crimp machine using a doctor blade.

[0275] For example, the pressure applied by the doctor blade may be 1.96 N / cm 2< (0.2 kgf / cm 2< ) or more, 2.94 N / cm 2< (0.3 kgf / cm 2< ) or more, 3.92 N / cm 2< (0.4 kgf / cm 2< ) or more, or 4.90 N / cm 2< (0.5 kgf / cm 2< ) or more. In addition, pressure of 14.71 N / cm 2< (1.5 kgf / cm 2< ) or less, 13.73 N / cm 2< (1.4 kgf / cm 2< ) or less, 12.75 N / cm 2< (1.3 kgf / cm 2< ) or less, 11.77 N / cm 2< (1.2 kgf / cm 2< ) or less, 10.79 N / cm 2< (1.1 kgf / cm 2< ) or less, or 9.81 N / cm 2< (1.0 kgf / cm 2< ) or less may be applied by the doctor blade.

[0276] In some embodiments, the crimp-imparting process may be performed at a temperature in the range of 120 to 250 °C. When the temperature is excessively low, the shape stabilization effect of crimps may become poor, and when the temperature is excessively high, the concentration of oil components in the stuffer box increases, making crimp formation difficult. Therefore, considering the aforementioned steam pressure and other factors, the temperature may be suitably controlled in the range of 130 °C or more, 140 °C or more, or 150 °C or more, and 200 °C or less, 180 °C or less, or 160 °C or less.<(g) Other Processes>

[0277] After the crimp-imparting process, an appropriate post-treatment may be further performed.

[0278] In an embodiment, a second emulsion treatment (g1) may be additionally performed. Through this second emulsion treatment, the tow may be given greater flexibility. The second emulsion treatment may be performed in the same way or in a manner analogous to the emulsion treatment process (d) described above.

[0279] Specifically, the second emulsion treatment may be performed by applying an emulsion to the lyocell tow that has been processed by a crimper. This may function advantageously in various processes involved in manufacturing a smoking article filter. For example, the second emulsion treatment may not only improve the spreadability of fibers and filters even under air flow during a spreading process, but may also reduce fiber breakage during a stretching process.

[0280] The second emulsion treatment may be carried out either before or after the binder treatment. Alternatively, the second emulsion treatment may be performed regardless of whether there is a binder treatment.

[0281] Even if the second emulsion treatment as described above is performed, the second emulsion treatment process may be carried out such that the emulsion content or OPU content in the material falls within the above-described range.

[0282] In some embodiments, a drying treatment (g2) may be additionally performed. This drying may be carried out, for example, at a temperature in the range of 100 to 130 °C. The drying method or procedure is not particularly limited, and any known technique may be employed. For example, the drying may be carried out by applying hot air to the tow, or by passing the tow through, or allowing the tow to remain in, a temperature-controlled room for a certain period of time.

[0283] According to an aspect, the present disclosure provides a lyocell material obtained by the above-described method of preparing a lyocell material.

[0284] According to an aspect, the present disclosure provides a lyocell material obtainable by the above-described method of preparing a lyocell material.[Smoking Article]

[0285] Although not particularly limited, the lyocell material prepared by the aforementioned 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.

[0286] For example, the lyocell material may be included in a combustible cigarette. As another example, the lyocell material may be included in a heat-not-burn cigarette, and the heat-not-burn cigarette may be used in combination with an aerosol-generating device (not shown).

[0287] For example, when used as a heat-not-burn smoking article, the smoking article may be separately insertable into the aerosol-generating device. Here, the aerosol-generating device may include a receiving recess to accommodate the aerosol-generating article, and may further include a heater for heating the aerosol-generating article to produce an aerosol, a controller for overall operation of the aerosol-generating device, a battery for providing power for the aerosol-generating device's operation, and a sensor for detecting insertion of the aerosol-generating article into the aerosol-generating device.

[0288] The smoking article may include a tobacco medium part, a smoking article filter, and a wrapper, wherein the smoking article filter may be disposed at either end of the tobacco medium part, for example, at the front end or the rear end. The tobacco medium part and the smoking article filter may each include a single segment, or may independently include a plurality of segments.

[0289] The tobacco medium part may include a tobacco material, and the tobacco material may include nicotine. Additionally, the tobacco medium part may further include an excipient.

[0290] The excipient may include a binder, a filler, and other additives. For example, a tobacco medium included in the tobacco medium part may be in the form of granules including a tobacco material, an excipient, or the like.

[0291] For example, to maintain a consistent shape, strength, and mass of the tobacco medium part, a filler may additionally be included. For example, the lyocell material may be included in the tobacco medium part. In addition, the lyocell material may be used as a filler.

[0292] The wrapper may be subdivided into a cigarette paper that wraps the tobacco medium part, a filter wrapper that encloses the filter part, and a tipping wrapper that joins the tobacco medium part and the filter, or the like.[Smoking Article Filter]

[0293] The lyocell material may be used in a smoking article filter. The lyocell material may be a lyocell tow. In an embodiment, the lyocell tow includes a crimped lyocell multifilament.

[0294] For example, the present disclosure relates to a smoking article filter. The smoking article filter may include a lyocell material, and the lyocell material may be the same as described above. In addition, the smoking article filter may include a lyocell tow, and the lyocell tow may be the same as described above.

[0295] In addition, the lyocell material includes the emulsion in an amount of 0.1 wt% or more based on 100 wt% of the entire lyocell material. The descriptions regarding the components and amounts of the emulsion in embodiments of the present disclosure are the same as those described above.

[0296] In some embodiments, the single filament fineness of filaments constituting the lyocell multifilament may be 1.67 dtex to 8.89 dtex (1.5 to 8.0 denier). The specific numerical values are the same as those described above.

[0297] In some embodiments, the crimped lyocell multifilament may be a lyocell material having a total fineness of 1,667 tex to 6,111 tex (15,000 to 55,000 denier) and preferably, may be a lyocell tow. The specific numerical values are the same as those described above.

[0298] In some embodiments, the crimped lyocell multifilament may have 3.94 to 19.71 crimps per centimeter (10 to 50 crimps per inch). The specific numerical values are the same as those described above.

[0299] In some embodiments, the smoking article filter may further include a binder on the surface of the crimped lyocell multifilament or between the crimped lyocell multifilaments. The binder increases the hardness of the smoking article filter produced from the tow, thereby preventing problems such as the filter being jammed during the filter manufacturing process or the cigarette manufacturing process. Details regarding the types, components, and amounts of binders that can be used are the same as previously described.

[0300] In some embodiments, the smoking article filter may further include a wrapper (which may be referred to as wrapping paper, filter paper, or filter wrapper). For example, the wrapper may be a porous or non-porous paper that encloses the aforementioned lyocell tow and helps maintain the filter shape (e.g., cylindrical).

[0301] In some embodiments of the present disclosure, the smoking article filter may have a predetermined shape and size.

[0302] For example, the filter may have a rod shape. More specifically, the smoking article filter may have a cylindrical shape.

[0303] In addition, the filter may have, for example, a length of 10 to 50 mm. Specifically, 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 may have 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.

[0304] In some embodiments of the present disclosure, the filter having such a length may have a circular cross-section, and the circumference of the circular cross-section may be 10 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 may have 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.

[0305] In some embodiments, the smoking article filter may include a lyocell tow and a filter wrapper. Details regarding the lyocell tow and the filter wrapper are the same as previously described and are therefore omitted.

[0306] The wrapper may be a porous or nonporous paper that encloses the aforementioned lyocell tow and is capable of maintaining the filter shape (e.g., cylindrical).

[0307] In an embodiment, if a porous wrapper is used, the wrapper may have a porosity of 10 to 50,000 coresta unit (CU). Coresta Unit may be defined as the volumetric flow rate (cm 3< ·min -1< ) of air passing through a 1 cm 2< substrate sample (i.e., porous wrapper) under a 1 kPa pressure difference. Specifically, the lower limit of the porosity of the wrapper 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 may have an upper limit of, 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 embodiment of the present disclosure, the wrapper may have a porosity in the range of 22,000 to 26,000 CU, or 23,000 to 25,000 CU.

[0308] In some embodiments, the wrapper may have a basis weight of 15 to 60 g / m 2< . Specifically, the basis weight of the wrapper may have a lower limit of, for example, 20 g / m 2< or more, 25 g / m 2< or more, 30 g / m 2< or more, 35 g / m 2< or more, 40 g / m 2< or more, 45 g / m 2< or more, 50 g / m 2< or more, or 55 g / m 2< or more, and may have an upper limit of, for example, 55 g / m 2< or less, 50 g / m 2< or less, 45 g / m 2< or less, 40 g / m 2< or less, 35 g / m 2< or less, 30 g / m 2< or less, 25 g / m 2< or less, or 20 g / m 2< or less. In an embodiment of the present disclosure, the wrapper may have a basis weight of 16 g / m 2< or more, 17 g / m 2< or more, 18 g / m 2< or more, 19 g / m 2< or more, 20 g / m 2< or more, or 21 g / m 2< or more, and 25 g / m 2< or less, 24 g / m 2< or less, 23 g / m 2< or less, 22 g / m 2< or less, or 21 g / m 2< or less.

[0309] Although not particularly limited, the weight of a rod-shaped filter may be 50 mg or more. Specifically, 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 may have 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.

[0310] Details regarding other smoking article filters or materials included therein are as previously described and are therefore omitted.[Method of Preparing Smoking Article Filter]

[0311] For example, the present disclosure relates to a method of preparing a smoking article filter. The method may include the above-described method of preparing the lyocell material and be a method of preparing the above-described lyocell-based smoking article filter.

[0312] With respect to the method of preparing a smoking article filter, except for the process of preparing the filter, the other processes are identical to those described above for preparing the lyocell material and will not be repeated. Furthermore, any redundant descriptions with the foregoing are omitted.

[0313] The process of preparing the filter may be suitably performed by those skilled in the art according to known methods. For example, the filter may be prepared by forming a wrapper filled with lyocell material into a rod shape. Alternatively, the filter may be prepared by cutting a rod-shaped filter paper filled with lyocell material to an appropriate length. Details regarding the wrapper are as previously described.

[0314] Although not particularly limited, the lyocell material may optionally be subjected to additional processes such as opening or plasticizer treatment prior to being filled into the filter paper. Opening the lyocell material may increase the surface area of the lyocell material. For example, the lyocell material may be opened by applying an external force in the longitudinal, transverse, and / or thickness directions.

[0315] Preferably, the lyocell material used in the manufacture of the smoking article filter may be a lyocell tow.

[0316] Although not particularly limited, a known cellulose acetate multifilament may also be included in the smoking article filter, to the extent that it does not interfere with the objectives of the present disclosure. The cellulose acetate multifilament may be mixed with the lyocell multifilament. The cellulose acetate multifilament may be included in a segment distinct from the segment containing the lyocell multifilament.Advantageous Effects of Invention

[0317] The present disclosure provides a lyocell material for smoking article filters capable of replacing commercially available cellulose acetate (CA), and a smoking article filter including the lyocell material. Specifically, by controlling the particle size of ground pulp, a lyocell dope with improved uniformity and spinnability is provided. The uniformity of lyocell monofilaments and lyocell multifilaments obtained by spinning the lyocell dope can be enhanced.Mode for the Invention

[0318] The operation and effects of the disclosure will be described in detail through specific embodiments set forth below. However, these embodiments are presented by way of example only and shall not be construed to limit the scope of the disclosure in any manner.

[0319] The lyocell material was prepared according to the process described in the following Preparation Example. Unless otherwise specified, the conditions used were within the scope of the foregoing description.[Preparation Example]

[0320] Ground pulp with a controlled particle size was transferred by a loss-in weight feeder and mixed into an aqueous NMMO solution, and a lyocell dope of 11 wt% concentration for preparing a lyocell material was prepared.

[0321] While maintaining a spinning temperature of 110 °C at the spinning nozzle, the extrusion rate and spinning speed were appropriately controlled, and the lyocell dope was subjected to spinning.

[0322] The filament-shaped lyocell dope extruded from the spinning nozzle passed through an air gap section and was supplied to a coagulation liquid (a coagulation liquid containing 75 wt% of water and 25 wt% of NMMO, at a temperature of about 25 °C) in a coagulation bath. At this time, the cooling air in the air gap section had a temperature of 8 °C and a flow rate of 200 Nm 3< / h, and the lyocell dope underwent first coagulation. Additionally, using a sensor and a refractometer, the concentration of the coagulation liquid was continuously monitored.

[0323] The coagulated lyocell filaments were then washed. Specifically, the filament was fed to a take-up roller, and residual NMMO in the filament was removed with a washing liquid sprayed from a washing apparatus. The washed filament was then immersed in a bath designed with a predetermined emulsion concentration.

[0324] The filament was subjected to a pressure of 19.6 N / cm 2< (2 kgf / cm 2< ) by a nip roll installed at the bath discharge section and was then fed into a crimp machine for wrinkle formation. Specifically, the lyocell material (lyocell tow) was prepared by setting the pressure of a press roller to 24.52 N / cm 2< (2.5 kgf / cm 2< ), and the pressure of a doctor blade to 4.90 N / cm 2< (0.5 kgf / cm 2< ).

[0325] The prepared lyocell tow has a single filament fineness of 2.22 dtex to 8.88 dtex (2.0 to 8.0 denier), a total fineness of 3,333 tex to 6,110 tex (30,000 to 55,000 denier), and a crimp count of 5.91 crimps / cm to 18.05 crimps / cm (15 to 55 crimps / inch).Examples 1 to 5

[0326] Lyocell materials were prepared according to Preparation Example 1, with the particle size of ground pulp controlled as shown in Table 1 below.Comparative Examples 1 to 4

[0327] Lyocell materials were prepared according to Preparation Example 1, with the particle size of ground pulp controlled as shown in Table 1 below.

[0328] The particle size of ground pulp used in each Example and Comparative Example was measured using a particle size analyzer from MALVEN (model name: Mastersizer 3000). [Table 1]Average Particle Size (µm)D 90 (µm)SpanExamples1137.0232.91.92165.0379.52.53104.0270.42.84344.0684.62.25264.0660.02.7Comparative Examples152.5113.01.32247.0938.64.13221.0861.94.34357.01356.64.1 <Experiment 1: Processability Evaluation of Lyocell Dope>

[0329] The hourly flow rate of ground pulp transported by a loss-in-weight feeder was measured. Based on the measured hourly flow rate, the average flow rate, minimum flow rate, and maximum flow rate were calculated. The average flow rate was defined as the flow rate per unit time. Based on the calculated values, the flow rate deviation (%) was calculated according to Formula 3 below:

[0330] Additionally, when the flow rate deviation was 10.0 % or less, the feeding stability of ground pulp was evaluated as good. Conversely, when the flow rate deviation exceeded 10.0 %, the feeding stability of ground pulp was evaluated as poor.

[0331] Meanwhile, each lyocell dope of Examples 1 to 5 and Comparative Examples 1 to 4 was stirred at 110 °C for 1 hour. Each stirred lyocell dope was applied onto a prepared glass plate, and the presence or absence of undissolved ground pulp was visually evaluated. The presence or absence of undissolved ground pulp was evaluated three times in the same manner, and if undissolved ground pulp was observed even once, the NMMO solubility was evaluated as poor. [Table 2]Flow rate deviation during ground pulp feeding (%)Feeding stabilityNMMO solubilityExamples13.3GoodGood24.1GoodGood33.5GoodGood42.8GoodGood52.5GoodGoodComparative Examples117.6PoorPoor215.6PoorPoor311.1PoorPoor417.4PoorPoor

[0332] The lyocell dopes of Examples 1 to 5 were confirmed to contain no ground pulp. In contrast, for Comparative Examples 1 to 4, clumping of ground pulp was confirmed within the lyocell dope, and undissolved ground pulp was also visually confirmed.<Experiment 2: Spinnability Evaluation of Lyocell Dope>

[0333] During the extrusion process of lyocell dope, the average pressure, minimum pressure, and maximum pressure of the lyocell dope were measured. Based on the measured values, the pressure deviation (%) was calculated according to Formula 4 below:

[0334] Additionally, when the pressure deviation was 15.0 % or less, the spinning stability of lyocell dope was evaluated as good. Conversely, when the pressure deviation exceeded 15.0 %, the spinning stability of lyocell dope was evaluated as poor. [Table 3]Pressure deviation during operation (%)Spinning stabilityExamples15.5Good25.4Good33.6Good43.8Good55.1GoodComparative Examples120.2Poor215.8Poor318.6Poor417.1Poor

[0335] The lyocell multifilaments obtained by spinning the lyocell dopes of Examples 1 to 5 were evaluated as having good spinning stability. In contrast, the lyocell multifilaments obtained by spinning the lyocell dopes of Comparative Examples 1 to 4 were evaluated as having relatively poor spinning stability, resulting in reduced uniformity of the lyocell multifilaments.<Experiment 3: Fineness Deviation Evaluation>

[0336] The fineness uniformity of the lyocell multifilaments obtained by spinning the lyocell dopes of Examples 1 to 5 and Comparative Examples 1 to 4, and the lyocell materials containing the respective lyocell multifilaments, was evaluated in terms of first fineness deviation and second fineness deviation. The first fineness deviation can be understood as the deviation of fineness measured from lyocell multifilaments before crimping is applied. The second fineness deviation can be understood as the deviation of fineness measured from lyocell multifilaments after crimping is applied. The evaluated results are shown in Table 4 below.

[0337] The first fineness deviation was calculated according to Formula 5 below. Before measuring the first fineness deviation, the lyocell multifilaments obtained by spinning the lyocell dope were stabilized for 24 hours under constant temperature of 20 °C and constant humidity of 65 % RH. Subsequently, skein-type samples (first samples) with a length of 90 m were prepared using a denier creel with a circumference of 1.125 m. The fineness of each first sample was measured according to Formula 5-1. The maximum value, minimum value, and average value among the fineness of the first samples were selected as the first maximum fineness, first minimum fineness, and first average fineness, respectively.

[0338] For calculating the second fineness deviation, 2 m length samples were collected from the lyocell material. The lyocell material was stabilized for 24 hours under constant temperature of 20 °C and constant humidity of 65 % RH. Subsequently, the samples were additionally stabilized by applying a load of 2 kg. The additionally stabilized samples were cut to 90 cm length to prepare second samples. The second fineness deviation was calculated according to Formula 6 below. The fineness of each second sample was measured according to Formula 6-1. The maximum value, minimum value, and average value among the fineness of the second samples were selected as the second maximum fineness, second minimum fineness, and second average fineness, respectively. Fineness of second sample = Weight of second sample g * 10000 [Table 4]First fineness deviation (%)Second fineness deviation (%)Examples14.112.227.211.435.915.647.317.459.418.2Comparative Examples113.421.6211.822.1314.222.4415.323.5

[0339] Referring to the first fineness deviation in Table 4 above, the fineness of the lyocell multifilaments of Examples 1 to 5 was confirmed to have a deviation of less than 10 %, while the fineness of the lyocell multifilaments of Comparative Examples 1 to 4 was evaluated to have a deviation exceeding 11 %. From these evaluation results, it is confirmed that the lyocell multifilaments of Examples 1 to 5 have more uniform fineness compared to the lyocell multifilaments of Comparative Examples 1 to 4.

[0340] Additionally, referring to the second fineness deviation in Table 4, the fineness of the lyocell materials of Examples 1 to 5 was confirmed to have a deviation of about 19 % or less, while the fineness of the lyocell materials of Compartive Examples 1 to 4 was evaluated to have a deviation exceeding 21 %. From these evaluation results, it is confirmed that the lyocell materials of Examples 1 to 5 have more uniform fineness compared to the lyocell materials of Comparative Examples 1 to 4.

[0341] Referring to these evaluation results, filters including the lyocell materials of Examples 1 to 5 are expected to provide more uniform characteristics, for example, uniform filtration performance and uniform mechanical properties, compared to filters including the lyocell materials of Comparative Examples 1 to 4.

Claims

1. A lyocell dope comprising N-methylmorpholine N-oxide (NMMO) and ground pulp dissolved in the NMMO, wherein the ground pulp has a particle size span value of 1.4 to 4.0, and the particle size span value is calculated according to Formula 1: Span = D 90 − D 10 / D 50 wherein in Formula 1, D10 is a particle size of the ground pulp at 10 % cumulative distribution, D90 is a particle size of the ground pulp at 90 % cumulative distribution, and D50 is a particle size of the ground pulp at 50 % cumulative distribution.

2. The lyocell dope of claim 1, wherein the ground pulp has a D90 of 800 µm or less, and / or wherein the ground pulp has a D90 of 150 µm or more.

3. The lyocell dope of claim 1, wherein the ground pulp has an average particle size of 400 µm or less, and / or wherein the ground pulp has an average particle size of 80 µm or more.

4. The lyocell dope of claim 1, wherein the ground pulp has a D10 of 120 µm or less, and / or wherein the ground pulp has a D10 of 10 µm or more.

5. The lyocell dope of claim 1, wherein the particle size of the ground pulp is all 900 µm or less.

6. The lyocell dope of claim 1, wherein the ground pulp has a flow rate deviation of 10.0 % or less, and / or wherein the ground pulp has a flow rate deviation of 2.0 % or more.

7. A lyocell material comprising a crimped lyocell multifilament, wherein a first fineness deviation is 11.0 % or less, and the first fineness deviation is calculated according to Formula 5: wherein in Formula 5, the first maximum fineness, the first minimum fineness, and the first average fineness are a maximum value, a minimum value, and an average value, respectively, among fineness values of a first sample, and the fineness of the first sample is calculated according to Formula 5-1:

8. The lyocell material of claim 7, wherein the number of the crimps is 3.94 crimps / cm (10 crimps / inch) to 23.64 crimps / cm (60 crimps / inch).

9. The lyocell material of claim 7, wherein the lyocell multifilament has a single filament fineness of 1.67 dtex to 8.89 dtex (1.5 to 8.0 denier), and / or wherein the lyocell material has a total fineness of 1,667 tex to 6,111 tex (15,000 to 55,000 denier).

10. The lyocell material of claim 7, wherein the lyocell material is a lyocell tow.

11. The lyocell material of claim 7, wherein the lyocell material is for use in a smoking article filter.

12. A smoking article filter comprising the lyocell material according to any one of claims 7 to 11.

13. A smoking article comprising the smoking article filter according to claim 12.

14. A method of preparing a lyocell material, the method comprising: preparing a lyocell dope comprising ground pulp; spinning the lyocell dope; coagulating; obtaining a lyocell multifilament; water-washing; treating with an emulsion; and imparting crimp, wherein the ground pulp has a flow rate deviation of 10.0 % or less.

15. A method of preparing a lyocell material, the method comprising: preparing a lyocell dope; spinning the lyocell dope; coagulating; obtaining a lyocell multifilament; water-washing; treating with an emulsion; and imparting crimp, wherein ground pulp included in the lyocell dope has a particle size span value of 1.4 to 4.0, and the particle size span value is calculated according to Formula 1: Span = D 90 − D 10 / D 50 wherein, in Formula 1, D10 is a particle size of the ground pulp at 10 % cumulative distribution, D90 is a particle size of the ground pulp at 90 % cumulative distribution, and D50 is a particle size of the ground pulp at 50 % cumulative distribution.

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