Sustainable filters and methods for manufacturing them

Abstract

A method for producing sustainable filter material for use in smoking articles, aerosol generating articles, etc., comprising: a) providing a longitudinally advancing flow of airlaid material; b) subjecting the longitudinally advancing airlaid material to a superheated gas; and c) drying the longitudinally advancing airlaid material by exposure to a high-temperature gas (for example, after subjecting the airlaid material to a superheated gas).

Description

[Technical Field]

[0001] The present invention provides a sustainable filter material for use in smoking articles such as cigarettes, tobacco heating products, or non-combustion heating products, along with a method for manufacturing the same. [Background technology]

[0002] Filter materials for use in smoking products such as cigarettes, heated tobacco products, or heat-not-burn (HNB) products can be manufactured from several different materials. According to Euromonitor International, 98% of commercially available cigarette filters contain at least some cellulose acetate. However, cellulose acetate is not biodegradable, and as a result, cigarette filter materials (and cigarette butts) containing cellulose acetate can remain in the environment for many years. Therefore, there is a need for filter materials (such as paper) that do not contain disposable plastics and are easily biodegradable.

[0003] Airlaid nonwoven paper is an alternative filtering material to cellulose acetate. Filters containing airlaid paper as a filtering material are well known in the art. Airlaid paper filters offer several advantages over cellulose acetate filters in terms of improved biodegradability and higher filtering efficiency at a given pressure drop. However, airlaid paper filters also have several disadvantages compared to cellulose acetate filters. Due to the manufacturing process of airlaid paper material, the material itself has high variability in weight and thickness. When converted into a filter, this high variability results in significant non-uniformity in the uneven pressure drop across the filter, reducing the absorption of the user's saliva and degrading the quality of the taste, as well as an unsightly appearance before and after smoking (as a result of discoloration). Therefore, the smoking experience of a rolled cigarette using a conventional airlaid filter is inferior to that of a rolled cigarette using a conventional cellulose acetate filter.

[0004] Therefore, it is desirable to provide new filter materials (e.g., modified airlaid materials) for use in smoking articles (e.g., cigarettes, heated tobacco products, non-combustible heating (HNB) products) that offer acceptable filtering characteristics (e.g., pressure unevenness, aerosol temperature) while improving upon known filter materials by providing a better customer experience (e.g., taste, absorption) and being more easily biodegradable (e.g., from a combination of increased absorption and decreased tensile strength). [Overview of the Initiative]

[0005] In a first embodiment of the present invention, a method is provided for producing a sustainable filter material for use in smoking articles, aerosol generating articles, etc., comprising: a) providing a longitudinally advancing flow of airlaid material; b) subjecting the longitudinally advancing airlaid material to a superheated gas (e.g., steam); and c) drying the longitudinally advancing airlaid material (e.g., after subjecting the airlaid material to a superheated gas). The longitudinally advancing airlaid material can be dried by exposure to a high-temperature gas (e.g., hot air).

[0006] The applicants have surprisingly found that subjecting an airlaid paper material to a superheated gas (e.g., steam) flowing longitudinally weakens the bonds that bind the fibers together. This allows the airlaid paper material to stretch, reducing its overall strength, making it more prone to decomposition and / or tearing.

[0007] While not bound by theory, it is thought that the absorption of superheated gas vapor (e.g., water vapor) into the airlaid paper material degrades the strong hydrogen bonds that bind the fibers together. Furthermore, it is thought that the longer the airlaid paper material is exposed to the superheated gas, the more these bonds will degrade.

[0008] Even more surprisingly, the applicants found that when airlaid paper material is subjected to a superheated gas (e.g., steam) and then dried by exposure to a high-temperature gas (e.g., hot air), the airlaid paper material is partially strengthened and acquires significantly different properties. The dual process of absorption and subsequent drying weakens the entire product while maintaining sufficient strength to function as intended. Thus, this weakened product becomes more easily decomposed, meaning it is more biodegradable than the original airlaid material while maintaining the expected functional performance.

[0009] While not bound by theory, it is thought that drying airlaid material partially reforms the interfiber bonds in the airlaid paper material. However, because the airlaid paper material is stretched in the previous process due to the deterioration of interfiber bonds, the final result is a significantly different fiber arrangement from the original airlaid paper material, which results in significantly different material properties.

[0010] The method may further include a step of embossing the airlaid material as it advances longitudinally (for example, after a drying step). The applicants have found that embossing the airlaid filter material reduces uneven pressure loss across the filter compared to embossing airlaid filter material that has not been subjected to the previous method step.

[0011] This method may further include gathering the airlaid material advancing in the longitudinal direction laterally to form a rod. This makes it possible to cut the rod to the appropriate size to form filter segments.

[0012] Sustainable filter materials (produced by the method of this embodiment of the present invention) may have an absorption capacity of 4.20 mg / mg or more, for example, 4.30 mg / mg to 4.60 mg / mg, for example, 4.49 mg / mg. Preferably, sustainable filter materials have an absorption capacity of 4.45 mg / mg to 4.55 mg / mg. The applicants have found that partial degradation of the airlaid material by the method step results in sustainable filter materials with a higher absorption capacity compared to filters made from airlaid filter materials that were not subjected to the heating and drying method step. Absorption capacity was measured using a capillary test commonly used in the art. Surprisingly, the applicants have found that the higher absorption capacity provided by sustainable filter materials produced by the method of this embodiment of the present invention results in less user saliva present at the mouth of the filter material, thus providing a better taste quality.

[0013] Sustainable filter material: 0.210 mg / mm 3 For example, 0.200 mg / mm³ 3 ~0.210 mg / mm³ 3 For example, 0.206 mg / mm³ 3 It may have a density of 0.203 mg / mm³. Preferably, the sustainable filter material has a density of 0.203 mg / mm³. 3 ~0.209 mg / mm³ 3 It has a density of . The applicants have found that sustainable filter materials produced by the method of this embodiment of the present invention have a lower density than filters made from the original airlaid material. This is because the fibers of the airlaid material are stretched, reducing the mass per unit area of ​​the airlaid material.

[0014] Sustainable filter materials may have a tensile strength of 1.2 N or less, for example, 0.5 N to 1.2 N, for example, 0.8 N. Preferably, sustainable filter materials have a tensile strength of 0.6 N to 1.0 N. The applicants have found that the tensile strength of sustainable filter materials is reduced compared to the original airlaid material due to degraded bonding and subsequent more separated material fibers. The applicants have found that sustainable filter materials produced by this embodiment of the present invention are easier to emboss during the embossing process, thereby reducing uneven pressure loss across filters made from this sustainable filter material. Furthermore, the applicants have found that sustainable filter materials are more easily degradable due to their reduced tensile strength combined with higher absorption capacity, and therefore the filter materials are more sustainable and environmentally friendly.

[0015] Sustainable filter materials may be paper (e.g., cellulose pulp). The paper may be, for example, filter paper, nonwoven paper, airlaid paper, or cellulose / lyocell / viscose-based paper. The paper may be nonwoven paper made from non-plastic plant fibers (e.g., flax, hemp, jute, sisal, Manila hemp, coconut, bamboo, starch, or wood pulp) or blends of these materials. Preferably, sustainable filtering materials do not contain cellulose acetate.

[0016] Sustainable filter materials may have a basis weight of 30 GSM to 200 GSM, for example, 45 GSM to 120 GSM, for example, 62 GSM. Preferably, sustainable filter materials have a basis weight of 50 GSM to 70 GSM.

[0017] The sustainable filter material, which may be paper, may have a thickness of 100 μm to 2000 μm, for example, 300 μm to 800 μm, for example, 400 μm. Preferably, the paper has a thickness of 300 μm to 500 μm.

[0018] The superheated gas used in the method of the present invention may be water vapor.

[0019] The pressure of the water vapor may be 0.5 bar to 1.2 bar, for example, 0.6 bar to 1 bar, for example, 0.8 bar. Preferably, the water vapor has a pressure of 0.70 bar to 0.90 bar.

[0020] The saturation of the water vapor may be 100°C to 150°C, for example, 110°C to 140°C, for example, 120°C to 130°C. Preferably, the saturation of the water vapor is 125°C.

[0021] The water vapor may be produced from distilled water. The applicants have found that by using distilled water to form superheated steam, it is ensured that the impurities that could be absorbed by the filter material are not carried by the water vapor.

[0022] The hot gas used to dry the airlaid material in the method of the present invention may be air.

[0023] The air used to dry the filter material may be 140°C to 350°C, for example, 200°C to 300°C, for example, 240°C. Preferably, the temperature of the air is 210°C to 270°C.

[0024] According to the present invention, in a second aspect, a filter for use in a smoking article, an aerosol-generating article, etc., comprising a longitudinally extending core including at least one filtering material segment, and optionally a wrapper surrounding the longitudinally extending core, wherein the filtering material segment comprises at least a) providing a flow advancing in the longitudinal direction of the airlaid material, b) subjecting the longitudinally advancing airlaid material to a hot gas, c) drying the longitudinally advancing airlaid material, for example, by exposing it to a hot gas (for example, after subjecting the airlaid material to the hot gas), and a filter is provided that includes a sustainable filter material produced according to the steps.

[0025] The manufacturing method may further include an embossing step of an airlaid material advancing in the longitudinal direction (for example, after the drying step).

[0026] The manufacturing method may further include collecting the airlaid material advancing in the longitudinal direction in the transverse direction to form a rod shape. Thereby, it becomes possible to cut the rod to an appropriate size to form a filter segment.

[0027] The sustainable filter material may have an absorption amount of 4.20 mg / mg or more, for example, 4.30 mg / mg to 4.60 mg / mg, for example, 4.49 mg / mg. Preferably, the sustainable filter material has an absorption amount of 4.45 mg / mg to 4.55 mg / mg. The advantages of such a sustainable filter material are detailed above.

[0028] The sustainable filter material is 0.210 mg / mm 3 or less, for example, 0.200 mg / mm 3 to 0.210 mg / mm 3 for example, 0.206 mg / mm 3 and may have a density of. Preferably, the filter material has a density of 0.203 mg / mm 3 to 0.209 mg / mm 3 The advantages of such a sustainable filter material are detailed above. <00,00108> The sustainable filter material may have a tensile strength of 1.2 N or less, for example, 0.5 N to 1.2 N, for example, 0.8 N. Preferably, the filter material has a tensile strength of 0.6 N to 1.0 N. The advantages of such a sustainable filter material are detailed above. <00,00111> Sustainable filter materials may be paper (e.g., cellulose pulp). The paper may be, for example, filter paper, nonwoven paper, airlaid paper, or cellulose / lyocell / viscose-based paper. The paper may be nonwoven paper made from non-plastic plant fibers (e.g., flax, hemp, jute, sisal, Manila hemp, coconut, bamboo, starch, or wood pulp) or blends of these materials. Preferably, sustainable filter materials do not contain cellulose acetate.

[0031] Sustainable filter materials may have a basis weight of 30 GSM to 200 GSM, for example, 45 GSM to 120 GSM, for example, 62 GSM. Preferably, the filter material has a basis weight of 50 GSM to 70 GSM.

[0032] If the sustainable filter material is paper, it may have a thickness of 100 μm to 2000 μm, for example, 300 μm to 800 μm, or for example, 400 μm. Preferably, the paper has a thickness of 300 μm to 500 μm.

[0033] Sustainable filtering materials may be embossed.

[0034] The superheated gas used in process (b) may be water vapor.

[0035] The steam may have a pressure of 0.5 bar to 1.2 bar, for example, 0.6 bar to 1 bar, for example, 0.8 bar. Preferably, the steam has a pressure of 0.70 bar to 0.90 bar.

[0036] Water vapor can have a saturation temperature of 100°C to 150°C, for example, 110°C to 140°C, or for example, 120°C to 130°C. Preferably, the saturation temperature of water vapor is 125°C.

[0037] Steam may be produced from distilled water.

[0038] The high-temperature gas used in process (c) may be air.

[0039] The high-temperature gas (e.g., air) may have a temperature of 140°C to 350°C, for example, 200°C to 300°C, or for example, 240°C. Preferably, the temperature of the high-temperature gas (e.g., air) is 210°C to 270°C.

[0040] According to the present invention, in a third embodiment, a filter for use in smoking articles, aerosol generating articles, etc., comprising a longitudinally extending core including at least one filtering material segment, and optionally a wrapper enclosing the longitudinally extending core, The filtering material has an absorption rate of (a) 4.20 mg / mg or more, for example, 4.30 mg / mg to 4.60 mg / mg (for example, 4.49 mg / mg), measured using a capillary tube test, and / or (b) 0.210 mg / mm 3 The following provides a filter comprising a sustainable filter material having, for example, a density of 0.210 mg / mm³ to 0.200 mg / mm³ (e.g., 0.206 mg / mm³) and / or (c) a tensile strength of 1.2 N or less, for example, 0.5 N to 1.2 N (e.g., 0.8 N). The advantages of filters containing such sustainable filter materials (biodegradability, taste, user experience) are detailed above.

[0041] Sustainable filtering materials may be embossed. The advantages of embossed sustainable filter materials are detailed above.

[0042] Sustainable filter materials may be paper (e.g., cellulose pulp). The paper may be, for example, filter paper, nonwoven paper, airlaid paper, or cellulose / lyocell / viscose-based paper. The paper may be nonwoven paper made from non-plastic plant fibers (e.g., flax, hemp, jute, sisal, Manila hemp, coconut, bamboo, starch, or wood pulp) or blends of these materials. Preferably, sustainable filtering materials do not contain cellulose acetate.

[0043] Sustainable filter materials may have a basis weight of 30 GSM to 200 GSM, for example, 45 GSM to 120 GSM, for example, 62 GSM. Preferably, sustainable filter materials have a basis weight of 50 GSM to 70 GSM.

[0044] In some examples, the sustainable filter material is paper, which may have a thickness of 100 μm to 2000 μm, for example, 300 μm to 800 μm, for example, 400 μm. Preferably, the paper has a thickness of 300 μm to 500 μm.

[0045] A filter according to a third aspect of the present invention may be manufactured according to the method of the first aspect of the present invention.

[0046] Preferably, the filter has pressure loss unevenness of 1% to 8%, for example 2% to 6%, or for example 3% to 5%. Preferably, the filter has pressure loss unevenness of 4%.

[0047] The segments of the sustainable filter material may be 5 mm to 50 mm in length, for example, 20 mm to 35 mm. Preferably, the segments of the sustainable filter material have a length of 15 mm to 35 mm, for example, 20 mm to 30 mm. Preferably, the segments of the sustainable filter material have a length of 27 mm.

[0048] Preferably, the filter has a length of 60 mm to 132 mm, for example, 75 mm to 120 mm, or for example, 90 mm to 110 mm. Preferably, the filter has a length of 108 mm.

[0049] Preferably, the circumference or perimeter of the filter is 14 to 30 mm, for example, 16 to 25 mm, for example, 23 to 25 mm. Preferably, the circumference or perimeter of the filter is 24 mm.

[0050] The sustainable filter material (in all aspects of the present invention) may be biodegradable and may have a biodegradability of more than 90% when measured according to ISO 14855-1 Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions - Method by analysis of evolved carbon dioxide. Preferably, the sustainable filter material exhibits at least 90% biodegradability after 6 months when measured according to ISO 14855-1.

[0051] Preferably, the sustainable filter material has a "Ready Biodegradability" level of biodegradability when measured according to the OECD 301B "Ready Biodegradability" method (modified Sturm test).

[0052] Sustainable filtering materials may be in the form of paper filtering materials or blends of different paper filtering materials and / or other biodegradable filtering materials. Paper may be coated with a hydrophobic coating or hydrophobic material.

[0053] The applicants have found that nonwoven paper (e.g., made from non-plastic plant fibers (e.g., flax, hemp, jute, sisal, Manila hemp, coconut, bamboo, starch, or wood pulp)) and / or airlaid paper are particularly suitable for the manufacture (and use as) sustainable filter materials because they possess excellent filtering properties and performance, as well as being biodegradable.

[0054] The applicants have found that the use of a paper (e.g., Plugwrap) wrapper with a basis weight of 50–150 gsm engaged around a segment containing sustainable filtering material is a suitable outer wrap and can provide stiffness (i.e., rigidity) similar to that of a cellulose acetate tube (e.g., a hollow acetate tube), and thus can provide a filter element with desirable stiffness (i.e., rigidity). Advantageously, the paper (e.g., Plugwrap) wrapper with a basis weight of 50–150 gsm is biodegradable.

[0055] The wrapper (e.g., plug wrap) engaged around the segment containing the sustainable filtering material may be non-porous. Alternatively, the wrapper (e.g., plug wrap) engaged around the segment containing the sustainable filtering material may be permeable to air with an air permeability of 0 to 32,000 cholesta units.

[0056] A filter according to the present invention (or a filter comprising sustainable filter material manufactured in accordance with the present invention) may be bonded to a cigarette-wound plug (e.g., an improved cigarette-wound plug as is well known in the art). The filter may be bonded to the cigarette-wound plug by ring chipping (i.e., an outer wrapper (e.g., chipping paper) that engages only around adjacent ends of the rolled filter and cigarette-wound plug, leaving much of the filter wrap exposed). The filter may be bonded to the cigarette-wound plug by full chipping overlap (i.e., an outer wrapper (e.g., chipping paper) that engages completely around the length of the rolled filter and adjacent ends of the cigarette-wound plug).

[0057] The wrapper (e.g., filter wrapper) may be perforated, for example, by laser perforation. The perforation may be applied to the wrapper (e.g., filter wrapper) before or after the filter is joined to the rolled cigarette plug. The perforation may be aligned (applied to the wrapper) with any cavities in the filter (if any). [Brief explanation of the drawing]

[0058] Next, the present invention will be described in more detail with reference to the attached figures. [Figure 1] A schematic side view of an apparatus for manufacturing a filter according to a first aspect of the present invention is shown. [Figure 2] A schematic diagram of one embodiment of the present invention is shown, which is an exemplary filter according to a second and third embodiment of the present invention, including a segment of sustainable filter material. [Figure 3] A schematic diagram of another embodiment of the present invention is shown, which is a filter comprising at least one segment of sustainable filter material. [Figure 4] A schematic diagram of another embodiment of the present invention is shown, which is a filter comprising at least one segment of sustainable filter material. [Figure 5] The graph shows experimental data of the pressure loss unevenness percentage for a given filter pressure loss for the filter according to the present invention, compared with a reference filter. [Figure 6] The graph shows experimental data of the total filter pressure loss for the filter according to the present invention at a given crimp depth of the filter material, compared to a reference filter.

[0059] Figure 1 shows an apparatus for forming a filter using nonwoven material, a process well known in the art, adapted to form the filter of the present invention by the method of the present invention. This apparatus produces a filter from a bale containing an airlaid nonwoven filtering material 102 having a thickness of approximately 1.3 mm and a width of approximately 1.3 mm. The airlaid material is drawn from the bale 102 by a paper drive unit 104 to form a tow that advances longitudinally into the filter material 106. The tow of the filter material 106 is then fed into a paper stabilizer and a splitter 108. The filter material 106 advances through the paper stabilizer and the splitter 108 by a first set of rollers 110.

[0060] A second set of rollers 112, located downstream and rotating faster than the first set of rollers 110, extends the tow of the filter material 106 between the first set of rollers 110 and the second set of rollers 112. The tow of the filter material is then supplied to a steam box 114. Inside the steam box 114, the tow of the filter material 106 is subjected to superheated steam at a pressure of 0.5 to 1.2 bar and a saturation temperature of 100°C to 150°C, for example, 110°C to 140°C, for example, 120°C to 130°C. Preferably, the steam saturation temperature is 125°C.

[0061] The tow of the steam-treated filter material 106 is stretched again by a third set of rollers 116 that rotate faster than a second set of rollers 112. The tow of the filter material 106 is fed through a hot air blowing chamber 118 to be dried. The temperature of the hot air in the hot air blowing chamber 118 is 140°C to 350°C. Once dried, the tow of the filter material 106 is fed through an embossing roller 120 that crimps the filter material 106 to a depth of 0.4 mm to 0.8 mm. The embossed / crimped filter material 106 is drawn out through a paper cone 122.

[0062] Strips of plug wrap 124, continuously drawn from reel 126, are pulled through a hot melt applicator 128 that applies hot melt adhesive to the plug wrap 124. The plug wrap 130 with adhesive is then drawn into garnish unit 132 along with the filter material 106 that has passed through paper cone 122. In garnish unit 132, the tow of the filter material 106 is formed into a rod shape, and the plug wrap 130 with adhesive is wound around the filter material 106. The plug wrap 130 is secured around the tow of the filter material 106 at overlapping and glued seams.

[0063] Next, the continuously manufactured wound rods 134 pass through a cutting unit 136 that cuts the rods 134 to the length of individual filter elements (not shown), the cutting unit 136 is followed by a moving unit 138, and finally ends on a packaging table 140.

[0064] Figure 2 illustrates a schematic diagram of one possible embodiment of the filter 200 according to the present invention, showing all components. The filter 200 comprises a mouth end 202 and a core 204 extending longitudinally from sustainable filtering material. The core 204 extending longitudinally from sustainable filtering material has a length of 27 mm and a circumference of 24 mm. The core 204 extending longitudinally from sustainable filtering material is formed from airlaid material, which is laterally assembled into a rod shape and held in place by a first wrapper 206 of 78 GSM weight nonporous plug wrap [Mudanjiang Hengfeng Paper Co., Ltd (Mundanjiang, China)]. The filter in Figure 2 is manufactured according to the method described in Figure 1 and has a tensile strength of 0.8 N, an absorption capacity of 4.49 mg / mg, and an absorption capacity of 0.206 mg / mm 3 It has a density of . The applicants found that a sustainable filter material subjected to superheated steam, dried with hot air, and then embossed provides a reduction in uneven pressure loss across the filter shown in Figure 2 (see the examples below). Furthermore, it was found that the absorption capacity of the sustainable filter material increased, resulting in the filter shown in Figure 2 having an improved taste quality during use due to the increased absorption of the user's saliva by the filter. The filter in Figure 2 was also found to have reduced tear resistance, which, when combined with the increased absorption capacity, resulted in a filter that is more readily biodegradable.

[0065] A further filter wrapper 208 of rigid plug wrap [Mudanjiang Hengfeng Paper Co.,Ltd (Mundanjiang, China)] weighing 78 GSM (please provide weight if necessary) wraps around the rolled longitudinal core 204. Both ends of the rolled filter 200 are coplanar with the rolled longitudinal core 204. The filter wrapper 208 has adhesive-applied overlapping longitudinal edges that provide an overlapping, glued seam (not shown) that holds the filter wrapper 208 around the rolled longitudinal core 204, and further adhesive in the form of anchor lines (not shown) aligned with the rolled longitudinal core 204 to hold the longitudinal core 204 in place.

[0066] The filter 200 may be joined to a cigarette-wound plug at the end opposite the mouth end 202 by a method well known in the art. A suitable cigarette plug is 11 mm to 40 mm in length, preferably 27 mm, and has a circumference of 15 mm to 30 mm. Such cigarette plugs are well known in the art. The filter 200 and the cigarette plug together form a smoking article containing the sustainable filter material of the present invention.

[0067] Figure 3 shows a schematic diagram of a filter 300 comprising a first longitudinally extending core 302 and a second longitudinally extending core 304 with a length of 27 mm adjacent to (e.g., in contact with) one end of the first longitudinally extending core 302. The first longitudinally extending core 302 contains a first filtering material in the form of an embossed paper sheet [airlaid nonwoven filtering material with a thickness of approximately 1.3 mm and a width of approximately 1.3 mm] embedded with activated carbon granules at a filling rate of 4.9 mg activated carbon / mm, the first filtering material being assembled into a rod shape and held in place by a first core wrapper 306 of 78 gsm nonporous plug wrap [Mudanjiang Hengfeng Paper Co., Ltd (Mundanjiang, China)]. The first longitudinally extending core 302 is manufactured by a method well known in the art, for example, embossed paper which may have activated carbon embedded in it, is applied by one or more rollers, and is then assembled into a rod shape and fixed in place by a first core wrapper 306 (e.g., a wrapper, e.g., a plug wrap) engaged around the rod (e.g., by overlapping and pasting seams as known in the art).

[0068] A second longitudinally extending core 304 comprises a 27 mm long sustainable filter material manufactured according to the present invention (for example, by the method described above with reference to Figure 1). The sustainable filter material is assembled laterally into a rod shape and held in place together with the wound first longitudinally extending core 302 by a wrapper 308 of 78 GSM weight nonporous plug wrap [Mudanjiang Hengfeng Paper Co., Ltd (Mundanjiang, China)].

[0069] A further filter wrapper 310 of 78GSM weight rigid plug wrap [Mudanjiang Hengfeng Paper Co.,Ltd (Mundanjiang, China)] wraps around the first longitudinally extending core 302 and the second longitudinally extending core 304. Both ends of the wound filter 300 are coplanar with the first longitudinally extending core 302 and the second longitudinally extending core 304. The filter wrapper 310 has overlapping longitudinal edges to which adhesive is applied, providing an overlapping and bonded seam (not shown) that holds the filter wrapper 310 around a first longitudinally extending core 302 and a second longitudinally extending core 304, and further adhesive in the form of anchor lines (not shown) aligned with the first longitudinally extending core 302 and the second longitudinally extending core 304 to hold the first longitudinally extending core 302 and the second longitudinally extending core 304 in place.

[0070] Figure 4 shows a schematic diagram of a filter 400 comprising a first longitudinally extending core 402 and a second longitudinally extending core 404. Both the first longitudinally extending core 402 and the second longitudinally extending core 404 contain sustainable filter material manufactured according to the present invention (for example, by the method described above with reference to Figure 1). The sustainable filter material is assembled laterally to form a rod. A filter wrapper 406 of 78 GSM weight rigid plug wrap [Mudanjiang Hengfeng Paper Co., Ltd (Mundanjiang, China)] wraps the first longitudinally extending core 402 and the second longitudinally extending core 404 such that the filter wrapper 406 defines a cavity 408 between the first longitudinally extending core 402 and the second longitudinally extending core 404.

[0071] The filter wrapper 406 has overlapping longitudinal edges to which adhesive is applied, providing an overlapping, bonded seam (not shown) that holds the filter wrapper 406 around a first longitudinally extending core 402 and a second longitudinally extending core 404, and further adhesive in the form of anchor lines (not shown) aligned with the first longitudinally extending core 402 and the second longitudinally extending core 404 to hold the first longitudinally extending core 402 and the second longitudinally extending core 404 in place.

[0072] experiment Sustainable filter materials prepared according to the present invention were subjected to numerous tests to determine their performance in areas such as tear resistance, absorption capacity, and pressure uniformity. Reference products included airlaid paper that had not been subjected to superheated steam and hot air.

[0073] Tensile strength was evaluated using the ASTM D689-17 test, which is well-known in the relevant art. Fixed and movable clamping methods were used, and the data shown in Table 1 is provided.

[0074] [Table 1]

[0075] As shown in Table 1, the tensile strength of the sustainable filter material (airlaid material subjected to superheated steam and dried with hot air) produced according to the present invention is significantly lower than that of the reference airlaid paper material. The applicants have found that this results in reduced tear resistance, which reduces the defect rate in all products, more stable smoke delivery to the user, and makes the material more sustainable because the material is more easily biodegradable.

[0076] The absorption capacity of sustainable filter materials was evaluated using the capillary tube test, a paper absorption test well-known in the relevant art, and compared with a reference material. The data are shown in Table 2 below.

[0077] [Table 2]

[0078] As shown in Table 2, the absorption capacity of the sustainable filter material produced according to the present invention is significantly higher than that of the reference airlaid paper material. The applicants found that increased absorption capacity of the sustainable filter material results in less user saliva present at the mouth of the filter material, thus providing a better taste quality.

[0079] The density of sustainable filter materials was evaluated and compared to a reference material. The data is shown in Table 3 below.

[0080] [Table 3]

[0081] As shown in Table 3, the density of the sustainable filter material produced according to the present invention is lower than that of the reference airlaid paper material. The applicants found that the reduction in density of the sustainable filter material due to the manufacturing process allows the sustainable filter material to more efficiently fill the filter space with material fibers that are more uniformly distributed across the filter. Surprisingly, this resulted in a reduction in uneven pressure loss across the filter, as shown in Figure 5.

[0082] The applicants also evaluated the effect on total filter pressure loss by varying the crimp depth of the sustainable filter material. These results were also evaluated against a reference material subjected to the same crimp depth. The data are shown in Figure 6.

[0083] As shown in Figure 6, the sustainable filter material produced by the method of the present invention provides a slightly reduced pressure drop at each given crimp depth compared to the reference material. However, when considered in conjunction with the data from Figure 5, the unevenness of pressure drop at each crimp depth (0.6 mm and 0.7 mm) is significantly lower when the filter is made from the sustainable filter material. The applicants have found that this results in a filter made from the sustainable filter material that provides more stable smoke delivery and, consequently, a better user experience.

Claims

1. A method for producing sustainable filter materials for use in smoking articles, aerosol-generating articles, etc. a) A step of providing a flow of airlaid material that advances in the longitudinal direction, b) A step of subjecting the airlaid material advancing in the longitudinal direction to a superheated gas, c) A method comprising the step of drying the longitudinally advancing airlaid material by, for example, exposure to a high-temperature gas (after, for example, the airlaid material has been subjected to the superheated gas).

2. The method according to claim 1, further comprising the step of embossing the longitudinally advancing airlaid material (for example, after the drying step).

3. The method according to claim 1 or 2, further comprising gathering the airlaid material advancing in the longitudinal direction laterally to form a rod shape.

4. The method according to any one of claims 1 to 3, wherein the sustainable filter material has an absorption capacity of 4.20 mg / mg or more, for example, 4.30 mg / mg to 4.60 mg / mg (for example, 4.49 mg / mg), and the absorption capacity is measured using a capillary test.

5. The aforementioned sustainable filter material is 0.210 mg / mm³ ３ For example, 0.200 mg / mm³ ３ ~0.210mg / mm ３ (For example, 0.206 mg / mm³) ３ The method according to any one of claims 1 to 4, having a density of ).

6. The method according to any one of claims 1 to 5, wherein the sustainable filter material has a tensile strength of 1.2 N or less, for example, 0.5 N to 1.2 N (for example, 0.8 N).

7. The method according to any one of claims 1 to 6, wherein the sustainable filter material is paper (i.e., cellulose pulp).

8. The method according to any one of claims 1 to 7, wherein the sustainable filter material has a basis weight of 30 GSM to 200 GSM (e.g., 62 GSM).

9. The method according to any one of claims 1 to 8, wherein the sustainable filter material includes paper, and the thickness of the paper is 100 μm to 2000 μm (for example, 400 μm).

10. The method according to any one of claims 1 to 9, wherein the superheated gas is water vapor.

11. The method according to claim 10, wherein the pressure of the steam is 0.5 bar to 1.2 bar (for example, 0.8 bar).

12. The method according to claim 10 or 11, wherein the saturation of the water vapor is 100°C to 150°C (for example, 125°C).

13. The method according to any one of claims 10 to 12, wherein the steam is produced from distilled water.

14. The method according to any one of claims 1 to 13, wherein the high-temperature gas is air.

15. The method according to claim 14, wherein the temperature of the air is 140°C to 350°C (for example, 240°C).

16. A filter for use in smoking articles, aerosol-generating articles, etc., comprising a longitudinally extending core containing at least one filtering material segment, and optionally a wrapper enclosing the longitudinally extending core, The filtering material segment comprises at least, a) A process of providing a flow of airlaid material that advances in the longitudinal direction, b) A step of subjecting the airlaid material advancing in the longitudinal direction to a superheated gas, c) A filter comprising a sustainable filter material manufactured according to a step of drying the longitudinally advancing airlaid material by, for example, exposure to a high-temperature gas (after, for example, the airlaid material has been subjected to the superheated gas).

17. The filter according to claim 16, wherein the sustainable filter material has an absorption capacity of 4.20 mg / mg or more, for example, 4.30 mg / mg to 4.60 mg / mg (for example, 4.49 mg / mg), and the absorption capacity is measured using a capillary test.

18. The aforementioned sustainable filter material is 0.210 mg / mm³ ３ For example, 0.200 mg / mm³ ３ ~0.210mg / mm ３ (For example, 0.206 mg / mm³) ３ The filter according to claim 16, having a density of ).

19. The filter according to claim 16, wherein the sustainable filter material has a tensile strength of 1.2 N or less, for example, 0.5 N to 1.2 N (for example, 0.8 N).

20. The filter according to any one of claims 16 to 19, wherein the sustainable filter material is paper (i.e., cellulose pulp).

21. The filter according to any one of claims 16 to 20, wherein the sustainable filter material has a basis weight of 30 GSM to 200 GSM (e.g., 62 GSM).

22. The filter according to any one of claims 16 to 21, wherein the sustainable filter material is paper, and the thickness of the paper is 100 μm to 2000 μm (for example, 400 μm).

23. The filter according to any one of claims 16 to 22, wherein the superheated gas is water vapor.

24. The filter according to claim 23, wherein the pressure of the water vapor is 0.5 bar to 1.2 bar (for example, 0.8 bar).

25. The filter according to claim 23 or 24, wherein the saturation of the water vapor is 100°C to 150°C (for example, 125°C).

26. The filter according to any one of claims 23 to 25, wherein the steam is produced from distilled water.

27. The filter according to any one of claims 16 to 26, wherein the high-temperature gas is air.

28. The filter according to claim 27, wherein the temperature of the air is 140°C to 350°C (for example, 240°C).

29. A filter for use in smoking articles, aerosol-generating articles, etc., comprising a longitudinally extending core containing at least one filtering material segment, and optionally a wrapper enclosing the longitudinally extending core, The filtering material has an absorption amount of (a) 4.30 mg / mg to 4.60 mg / mg (e.g., 4.49 mg / mg), measured using a capillary test, and / or (b) 0.210 mg / mm ３ to 0.200 mg / mm ３ (e.g., 0.206 mg / mm ３ ) of density, and / or (c) a tensile strength of 0.5 N to 1.2 N (e.g., 0.8 N), and includes a sustainable filter material.

30. The filter according to claim 29, wherein the sustainable filter material is paper (i.e., cellulose pulp).

31. The filter according to claim 29 or 30, wherein the sustainable filter material has a basis weight of 30 GSM to 200 GSM (e.g., 62 GSM).

32. The filter according to any one of claims 29 to 31, wherein the sustainable filter material is paper, and the thickness of the paper is 100 μm to 2000 μm (for example, 400 μm).

33. The filter according to any one of claims 29 to 32, wherein the sustainable filter material is manufactured according to the method described in any one of claims 1 to 15.

34. The filter according to any one of claims 29 to 33, wherein the filter has a pressure loss variation of 25 mmHg to 80 mmHg (for example, 47 mmHg) across the filter.

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