Filters for smoking or e-cigarette articles containing two-ply materials

Abstract

According to the present invention, there is provided a material that includes a paper substrate and a low density nonwoven substrate, the material being usable as a filter for a smoking article or an e-cigarette article.

Description

[Technical field]

[0001] According to the present invention, there is provided a filter comprising a biodegradable two-ply material, the filter comprising a paper substrate and a substrate obtainable by an airlaid or drylaid process, the filter of the present invention can be used as a filter for a smoking article or an e-cigarette article. [Background technology]

[0002] A filter for a smoking article or an electronic cigarette article has a perfect cylindrical shape and is usually composed of an outer wrapper made of plug wrap paper and a substrate disposed within the outer wrapper. The substrate prevents a user from inhaling tobacco particles, and the filter for a smoking article or an electronic cigarette article can capture harmful particulate matter such as tar contained in smoke or aerosol.

[0003] Conventional filters are made from cellulose acetate. Such conventional cellulose acetate filters have a nicotine trapping capacity that makes the smoke filtered by the filter perceptually satisfying to the user. In addition, the smoke filtered by such conventional filters has good organoleptic properties. However, such conventional filters degrade very slowly and do not disperse in water. This is particularly harmful because the filters are not consumed during smoking / inhaling of the smoking / e-cigarette article and are commonly found in the environment. Thus, cellulose acetate substrates have a significant impact on the environment.

[0004] In order to reduce the environmental impact of traditional filters, it has been proposed to replace the cellulose acetate substrate with a paper substrate obtained by a wet-laid process. The paper substrate is biodegradable and therefore decomposes quickly. However, the nicotine capture capacity of the filter made from the paper substrate is not satisfactory to the user in terms of the perception of the smoke filtered by the filter. In addition, the smoke filtered by the filter made from the paper substrate has a dry taste that is unsatisfactory to the user. Therefore, the user experience provided by the paper substrate obtained by the wet-laid process is not satisfactory compared to the cellulose acetate substrate.

[0005] It has also been proposed to replace the cellulose acetate substrate with a nonwoven substrate obtained by airlaid or drylaid methods. A dispersible filter including a nonwoven substrate obtained by airlaid method is described in Patent Document 1 (FR2009244). A filter including a nonwoven substrate obtained by drylaid method is described in Patent Document 2 (FR2009247). The filters described in Patent Documents 1 and 2 are said to have the same nicotine capture capacity as conventional cellulose acetate filters.

[0006] However, such conventional nonwoven substrates cannot be crimped. Crimping a substrate is the simplest means for controlling the pressure drop of a filter, and is therefore the most commonly used means. Therefore, the inability to crimp is disadvantageous. In order to control the pressure drop of a filter including such a conventional nonwoven substrate, it is necessary to change the thickness of the nonwoven substrate to adjust the weight of the filter material. However, it is the desire of manufacturers of filters for smoking articles or electronic cigarette articles to make the nonwoven substrate easily adaptable to various filters, as is the case with paper substrates that can be crimped to control the pressure drop of the filter without changing the thickness. Furthermore, the mechanical properties of the filter of Patent Document 2 are insufficient. In particular, the filter of Patent Document 2 is soft and easily crushed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] French Patent No. 2009244 [Patent Document 2] French Patent No. 2009247 Summary of the Invention [Problem to be solved by the invention]

[0008] There is therefore a need for a substrate that can be easily adapted to a variety of filters, that allows for the production of filters that have the same nicotine capture capacity as cellulose acetate filters, that provide a satisfactory user experience, and that have satisfactory mechanical properties.

[0009] The present inventors have discovered that a two-layer material can solve the above problems. [Means for solving the problem]

[0010] According to the present invention, there is provided a filter comprising two layers of material, 500mg / cm 3 ~200mg / cm 3 , especially 400 mg / cm 3 ~250mg / cm 3 , especially 390 mg / cm 3 ~300mg / cm 3 A paper substrate having a density of 7 mg / cm 3 ~60mg / cm 3 , especially 8 mg / cm 3 ~55mg / cm 3 , especially 10 mg / cm 3 ~45mg / cm 3 and a nonwoven substrate having a density of

[0011] Advantageously, the filters of the present invention have a nicotine-retaining capacity comparable to that of cellulose acetate filters, and superior to that of filters made from paper substrates, such that smoke filtered by the filters of the present invention is perceptually more pleasing to the user.

[0012] Furthermore, the smoke filtered by the filter of the present invention has organoleptic properties that are pleasing to the user.

[0013] Furthermore, the two-ply material can be easily adapted to various filters by, for example, varying the density of the paper substrate by crimping.

[0014] The filters of the present invention also have very satisfactory mechanical properties, in particular they are less prone to collapse than the filters described in WO 02 / 04313 and WO 02 / 04313.

[0015] Additionally, in contrast to cellulose acetate filters, the filters of the present invention, due to being constructed from a two-layer material, can degrade very quickly in the environment, which makes the filters of the present invention particularly advantageous as they have a smaller impact on the environment than cellulose acetate filters.

[0016] According to another aspect of the invention, there is provided a method of manufacturing a filter for a smoking article or an e-cigarette article, comprising the steps of: (a) producing the paper substrate by a wet laid process; (b) optionally shaping the paper substrate produced in step (a) above; (c) producing the nonwoven substrate by a drylaid or airlaid process; (d) bonding the paper substrate produced in step (a) above or the paper substrate produced in step (b) above and the nonwoven substrate produced in step (c) above together to form a two-ply material; (e) forming a rod from the two-layer material produced in step (d) above; (f) wrapping the rod with a sheet of plug wrap paper; (g) adhesively bonding the sheets of plug wrap paper together to obtain a rod of filter material; (h) cutting the rod of filter material to produce a filter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] According to the present invention, there is provided a filter comprising two layers of material, 500mg / cm 3 ~200mg / cm 3 , especially 400 mg / cm 3 ~250mg / cm 3 , especially 390 mg / cm 3 ~300mg / cm 3 A paper substrate having a density of 7 mg / cm 3 ~60mg / cm 3 , especially 8 mg / cm 3 ~55mg / cm 3 , especially 10 mg / cm 3 ~45mg / cm 3 and a nonwoven substrate having a density of

[0018] Without wishing to be bound by any theory, the inventors believe that the low density of the nonwoven substrate allows the two-layer material to have a high filter loading force. This high filter loading force allows the amount of two-layer material contained in the filter of the present invention to be reduced so that the filter of the present invention has the same nicotine capture capacity as a cellulose acetate filter. At first glance, such a reduction in the amount of two-layer material appears to change the mechanical properties of the filter of the present invention, especially the crush resistance. Surprisingly, this is not the case. Without wishing to be bound by any theory, the inventors believe that the filter of the present invention has good mechanical properties, especially good crush resistance, due to the high density of the paper substrate.

[0019] Therefore, by combining a high-density paper substrate with a low-density nonwoven fabric substrate, the filter of the present invention can have the following excellent properties: Satisfying nicotine capture ability, Adaptability to various filters, and Satisfactory mechanical properties, in particular satisfactory crush resistance.

[0020] As used herein, a "two-ply material" means a material in which a paper substrate forms a first layer and a nonwoven substrate forms a second layer, the first layer being in contact with the second layer.

[0021] In this application, "paper substrate" means a sheet made of wood fibers obtained by a wet-laid process.

[0022] The paper substrate of the two-ply material of the present invention is a paper substrate that is conventionally used to manufacture filters for smoking articles or electronic cigarette articles. The paper substrate of the two-ply material of the present invention can be obtained by a wet-laid method.

[0023] In this application, "nonwoven substrate" refers to a manufactured sheet consisting of a web or ply of unidirectionally or randomly oriented fibers that are bonded to one another by friction, cohesion, and / or adhesion. Traditionally, nonwoven substrates are obtained by dry-laid or air-laid processes. Thus, the nonwoven substrate of the two-ply material of the present invention can be obtained by dry-laid or air-laid processes.

[0024] Typically the two-ply material has a weight ratio of paper substrate:nonwoven substrate of 10:90 to 90:10, particularly 75:25 to 25:75, and especially 45:55 to 55:45.

[0025] Generally, the density of a paper substrate is calculated by dividing the basis weight of the paper substrate by the thickness of the paper substrate. The density of a nonwoven substrate is calculated in a similar manner.

[0026] Standard ISO 536:2012 can be used to determine the basis weight of paper and nonwoven substrates. Substrates are conditioned for at least 16 hours at 23°C and 50% humidity before measurement.

[0027] The thickness of the paper substrate and nonwoven substrate is 25 cm 2 The thickness can be measured using a deadweight micrometer with a measuring head of 1.0 mm. During the measurement, the substrate is placed between the two pressure surfaces for 10 seconds. The pressure between the two pressure surfaces during the thickness measurement is 0.5 kPa. The substrate is conditioned for at least 16 hours at 23°C and 50% humidity before the measurement.

[0028] The basis weight of the paper base material of the present invention is, for example, 20 g / m 2 ~60g / m 2 , especially 23g / m 2 ~55g / m 2 , especially 25 g / m 2 ~50g / m 2 It is.

[0029] The thickness of the paper base material of the present invention is, for example, 50 μm to 200 μm, particularly 75 μm to 150 μm, and especially 90 μm to 130 μm.

[0030] In one particular embodiment, the paper substrate has a thickness of 350 mg / cm 3 ~360mg / cm 3 and a thickness of 100 μm to 110 μm.

[0031] The basis weight of the nonwoven fabric substrate of the present invention is, for example, 20 g / m 2 ~65g / m 2 , especially 23g / m 2 ~60g / m 2 , especially 25 g / m 2 ~55g / m 2 It is.

[0032] The thickness of the nonwoven fabric substrate of the present invention is, for example, 700 μm to 6000 μm, particularly 900 μm to 4700 μm, and especially 1000 μm to 4500 μm.

[0033] In a first particular embodiment, the nonwoven substrate has a density of 10 mg / cm 3 ~40mg / cm 3 and a thickness of 1000 μmm to 2500 μm.

[0034] The dry-laid method is particularly suitable for obtaining the nonwoven substrate of this first particular embodiment. Thus, the nonwoven substrate of this embodiment can be obtained by the dry-laid method.

[0035] In a second particular embodiment, the nonwoven substrate has a density of 20 mg / cm 3 ~45mg / cm 3 and a thickness of 1200 μm to 2500 μm.

[0036] The airlaid process is particularly suitable for obtaining the nonwoven substrate of this second particular embodiment. Thus, the nonwoven substrate of this embodiment can be obtained by the airlaid process.

[0037] Those skilled in the art will know how to adjust the basis weight and thickness of paper and nonwoven substrates to achieve the desired density.

[0038] According to one embodiment, the nonwoven substrate comprises natural fibers.

[0039] In general, the natural fibers can account for 70% to 99% by weight, particularly 80% to 98% by weight, and even more particularly 85% to 98% by weight of the solids content of the nonwoven substrate.

[0040] As used herein, the term "natural fibers" refers to fibers of natural origin that have, optionally, been subjected to chemical or physical treatment, or both, to optimize their physical properties.

[0041] For example, the natural fibers of the nonwoven substrate are selected from wood fibers, leaf fibers, fruit fibers, seed fibers, bast fibers, stem fibers, reed fibers, and any combination thereof, in particular wood fibers, leaf fibers, seed fibers, bast fibers, and any combination thereof, especially wood fibers, bast fibers, and combinations thereof.

[0042] The wood fibers contained in the paper substrate and nonwoven substrate of the present invention are selected from hardwood pulp, bleached hardwood pulp, softwood pulp, bleached softwood pulp, softwood fluff pulp, lyocell fiber (cellulose fiber that is ground and dissolved in N-methylmorpholine N-oxide monohydrate in order to obtain fibers having various cross-sectional shapes (round, elliptical, cross-shaped, circular, lamellar cross-sections) whose length and mass per unit length are calibrated and can be selected as needed by a person skilled in the art), viscose fiber (calibrated length and mass per unit length are calibrated and can be selected as needed by a person skilled in the art), and the like. The fibers may be selected from: fibers obtained by dissolving the hydroxyl groups of cellulose with carbon disulfide (CS2) to obtain fibers with various cross-section shapes (round, elliptical, cruciform, circular, lamellar cross-sections) and then precipitating in the presence of sulfuric acid (H2SO4), and any combination thereof, in particular hardwood pulp, softwood pulp, softwood fluff pulp, lyocell fibers, viscose fibers, and any combination thereof, in particular softwood pulp, softwood fluff pulp, lyocell fibers, and any combination thereof.

[0043] In the present application, "bast fibers" refers to plant fibers contained in the bast of plants.

[0044] The bast fibers may be selected from hemp fibers, Indian hemp fibers, jute fibers, kenaf fibers, kudzu fibers, coinvine fibers, flax fibers, okra fibers, nettle fibers, papyrus fibers, ramie fibers, sisal fibers, esparto fibers, and any combination thereof, in particular hemp fibers, flax fibers, and combinations thereof, especially flax fibers.

[0045] Generally, the bast fibers are subjected to a pretreatment, and therefore may be selected from cottonized bast fibers, individualized bast fibers, retting bast fibers, bleached bast fibers, and any combination thereof, in particular cottonized bast fibers, individualized bast fibers, and combinations thereof.

[0046] In the present application, "seed fibers" means fibers obtained from the seeds of a plant. The seed fibers may be selected from cotton fibers, kapok fibers, loofah fibers, milkweed fibers, and any combination thereof, in particular kapok fibers.

[0047] According to a first particular embodiment, the natural fibres are wood fibres selected from softwood pulp, softwood fluff pulp, in particular softwood fluff pulp.

[0048] According to a second particular embodiment, the natural fibers are chosen from lyocell fibers, flax fibers, cotton fibers, and any combination thereof, in particular the combination of cottonized flax fibers and lyocell fibers.

[0049] According to a third particular embodiment, the natural fibers of the nonwoven substrate are a natural fiber blend comprising a combination of cottonized flax fibers and lyocell fibers; The cottonized flax fibers constitute more than 50% by weight of the solids content of the natural fiber mixture, in particular 70% to 98% by weight, and more particularly 85% to 95% by weight; The lyocell fibres make up less than 50% by weight of the solids content of the natural fibre blend, in particular between 2% and 30% by weight, more particularly between 5% and 15% by weight.

[0050] Generally, the wood fibres in the paper substrate may have a length of from 1mm to 3mm, in particular from 1.5mm to 2.7mm, especially from 2mm to 2.7mm.

[0051] Generally, the natural fibres of the nonwoven substrate may have a length of from 1mm to 150mm, particularly from 1.5mm to 100mm, and more particularly from 2mm to 60mm.

[0052] The length of natural fibres can be measured in various ways. For example, the length of natural fibres can be measured with a Classifiber KCF-V / LS device from Keisokki. The natural fibres are combed and individualised before measurement. The length of the fibres can be measured automatically by optical methods using the above mentioned device. The length of the fibres may also be measured microscopically at the required magnification using a projection microscope. A person skilled in the art will know how to select a suitable measurement method for the length of natural fibres.

[0053] According to one particular embodiment, the natural fibers of the nonwoven substrate have a length of 10 mm to 150 mm, in particular 15 mm to 100 mm, especially 20 mm to 60 mm.

[0054] The drylaid process is particularly suitable for obtaining natural fibers in the above range of lengths, and therefore the nonwoven substrate of this particular embodiment can be obtained by the drylaid process.

[0055] According to another particular embodiment, the natural fibres have a length of between 1 mm and 10 mm, in particular between 1.5 mm and 8 mm, and especially between 2 mm and 5 mm.

[0056] The airlaid process is particularly suitable for obtaining natural fibers having lengths in the above ranges, and therefore the nonwoven substrate of this other particular embodiment can be obtained by the airlaid process.

[0057] The natural fibers may also be cut to lengths in the ranges mentioned above. Conventional cutting techniques that can be used include guillotine cutting of the natural fibers and milling of the natural fibers with or without air cyclones or screen systems to remove overly short and overly long fibers.

[0058] The nonwoven substrate can be consolidated by chemical consolidation, needling, hydroentanglement, or any combination thereof, particularly chemical consolidation. These consolidation techniques are known to those skilled in the art and would know how to apply them to the nonwoven substrate of the present invention.

[0059] A binder is used for chemical consolidation, and therefore the nonwoven substrate may include a binder.

[0060] As used herein, "binder" refers to a compound that has properties that allow for consolidation of the nonwoven substrate.

[0061] The binders that are conventionally used to consolidate conventional nonwoven substrates are suitable for consolidating the nonwoven substrate of the present invention. Among these binders, it is advantageous to select water-soluble binders. Water-soluble is understood to refer to the binder's ability to dissolve in water at a certain temperature and with controlled agitation, so as to form a homogeneous solution at ambient temperature but not to form a suspension. Advantageously, the binder is water-soluble, so that it can be dispersed in the nonwoven substrate.

[0062] For example, the binder can be a natural polymer, a synthetic polymer or copolymer, or a combination thereof.

[0063] The natural polymer can be a polysaccharide, a cellulose derivative, or a combination thereof.

[0064] The polysaccharides that can be used as binders can be polysaccharides themselves or derivatives of polysaccharides, including starch, dextrin, gum arabic, or any combination thereof, especially starch.

[0065] The cellulose derivative may be selected from ethyl cellulose, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, alkali metal salts of carboxymethyl cellulose, and any combination thereof, in particular carboxymethyl cellulose.

[0066] Alkali metal salts of carboxymethylcellulose include potassium, sodium, and magnesium.

[0067] The synthetic polymer or copolymer can be, for example, polyvinyl alcohol, ethylene vinyl alcohol, polyvinyl acetate, polyvinyl chloride, styrene-butadiene, polybutadiene, polyacrylic acid, ethylene-vinyl acetate, or any combination thereof, particularly polyvinyl alcohol.

[0068] Generally, the binder can comprise from 1% to 30% by weight, particularly from 2% to 20% by weight, and especially from 2% to 15% by weight of the solids content of the nonwoven substrate.

[0069] According to another particular embodiment, the nonwoven substrate has a density of 10 mg / cm 3 ~40mg / cm 3 and A natural fiber mixture, the natural fiber mixture comprising 85% to 95% by weight of cottonized flax fiber and 5% to 15% by weight of lyocell fiber, based on the solid content of the natural fiber mixture; a binder, in particular starch, The natural fiber mixture accounts for 90% to 98% by weight of the solid content of the nonwoven substrate; The binder accounts for 2% to 10% by weight of the solid content of the nonwoven fabric substrate.

[0070] The nonwoven substrate of this particular embodiment can be obtained by a dry laid process.

[0071] According to another particular embodiment, the nonwoven substrate has a density of 20 mg / cm 3~45mg / cm 3 and Softwood fluff pulp; a binder, in particular starch, Softwood fluff pulp accounts for 80% to 95% by weight of the solid content of the nonwoven fabric substrate, The binder accounts for 5% to 20% by weight of the solid content of the nonwoven fabric substrate.

[0072] The nonwoven substrate of this particular embodiment can be obtained by an airlaid process.

[0073] The paper substrate of the two-ply material of the present invention can be shaped, in particular crimped. This shaping allows the properties of the paper substrate, and therefore the properties of the filter comprising the two-ply material of the present invention, to be modified. For example, crimping allows the density of the paper substrate, and therefore the density of the two-ply material, to be modified, which allows the pressure drop of the filter comprising the two-ply material of the present invention to be increased or decreased without changing the weight of the filter. In this way, the two-ply material can be easily adapted to various filters by shaping the paper substrate by known methods, such as crimping.

[0074] The two-ply material of the filter of the present invention can be combined with one or more substrates. The one or more substrates can be, independently of each other, a paper substrate or a nonwoven substrate. The paper substrate can be the paper substrate of the present invention. The nonwoven substrate can be the nonwoven substrate of the present invention.

[0075] According to one embodiment, the filter may be a filter for a smoking article or an e-cigarette article, comprising the two-ply material of the present invention described above.

[0076] As used herein, "smoking article" refers to an article that contains tobacco and / or any other plant material that is intended to be smoked. For example, a smoking article can be a machine-made cigarette, a hand-rolled cigarette, or a homemade cigarette.

[0077] Generally, a filter for a smoking article has a right cylindrical shape and comprises an outer wrapper of plug wrap paper for a smoking article, particularly a cigarette, and a two-ply material of the present invention as defined above disposed within the outer wrapper.

[0078] As used herein, "e-cigarette article" refers to an article containing tobacco and / or other plant material intended to be inhaled, which is inserted into a device that heats the tobacco / plant material without burning it, allowing delivery of an aerosol to a user. For example, an e-cigarette article can be a tobacco stick.

[0079] Generally, a filter for an electronic cigarette article has a true cylindrical shape and comprises an outer wrapper of an electronic cigarette article, in particular a plug wrap paper for a tobacco stick, and a two-layer material of the present invention as defined above disposed within the outer wrapper.

[0080] The filter of the present invention has a density of 100 mg / cm 3 ~300g / cm 3 , especially 150 mg / cm 3 ~250g / cm 3 , especially 140 mg / cm 3 ~200g / cm 3 The density of the sintered body may be 0.01 to 0.01.

[0081] Generally, the density of a filter is measured after the filter is manufactured by dividing the mass of the filter by its volume. For a perfectly cylindrical filter, the volume of the filter (V filter ) is calculated by the following formula: V filter =π×L×r 2 where r is the radius of the filter and L is the length of the filter.

[0082] The density of the filters of the present invention is higher than that of the filters of Patent Documents 1 and 2. Without wishing to be bound by any theory, the inventors believe that the mechanical properties of the filters, in particular the crush resistance, are due to the higher density of the filters of the present invention.

[0083] According to another aspect, the present invention relates to a smoking article comprising a filter as defined above.

[0084] According to another aspect, the present invention relates to an electronic cigarette article comprising a filter as defined above.

[0085] The present invention also relates to the use of the two-ply material as defined above in a filter, in particular a filter for a smoking article or a filter for an electronic cigarette article.

[0086] The present invention also relates to a method for producing a filter for a smoking article or an electronic cigarette article as defined above, comprising the steps of: (a) producing the paper substrate by a wet laid process; (b) optionally shaping the paper substrate produced in step (a) above; (c) producing the nonwoven substrate by a drylaid or airlaid process; (d) bonding the paper substrate produced in step (a) above or the paper substrate produced in step (b) above and the nonwoven substrate produced in step (c) above together to form a two-ply material; (e) forming a rod from the two-layer material produced in step (d) above; (f) wrapping the rod with a sheet of plug wrap paper; (g) adhesively bonding the sheets of plug wrap paper together to obtain a rod of filter material; (h) cutting the rod of filter material to produce a filter.

[0087] Generally, a filter for a smoking article or an e-cigarette article produced by the production method of the present invention has a perfect cylindrical shape and a plug wrap paper envelope for a filter of a smoking article or an e-cigarette article; and a bi-layer material as defined above disposed within the envelope.

[0088] The paper substrate and the nonwoven substrate are as defined above.

[0089] The wet-laid process for producing a paper substrate is a conventional process known to those skilled in the art, who will know how to adjust the parameters of this wet-laid process to produce the paper substrate of the two-ply material of the present invention.

[0090] Airlaid and drylaid processes for producing nonwoven substrates are conventional processes known to those skilled in the art, who will know how to adjust the parameters of the airlaid and drylaid processes to produce the two-ply material nonwoven substrate of the present invention.

[0091] The natural fibres of the nonwoven substrate may be a mixture of natural fibres, which may be obtained prior to step (c) above.

[0092] The method of the present invention can optionally include a step of cutting the natural fibers of the nonwoven substrate prior to step (c) above to obtain natural fibers having lengths within the ranges mentioned above. The step of cutting the natural fibers of the nonwoven substrate can be carried out by conventional techniques such as guillotine cutting of the natural fibers and milling of the natural fibers with or without air cyclones or screen systems to remove overly short and overly long fibers.

[0093] The natural fibers may be pre-treated bast fibers, such as cottonized bast fibers, individualized bast fibers, retting bast fibers, or any combination thereof, in particular cottonized bast fibers, individualized bast fibers, or any combination thereof.

[0094] Thus, the method of the present invention may comprise, prior to step (c) above, a treatment step of the bast fibres selected from retting, bleaching, cottonising, singulating and any combination thereof, in particular a step of cottonising, singulating or singulating followed by cottonising.

[0095] Cottonization is a known process in which fibers are attenuated for passing through a spinning mill. Those skilled in the art will know how to carry out the cottonization process.

[0096] Singulating is a process that separates all or part of a set of fibers from one another. Singulating can be performed, for example, by combing or chemical treatment.

[0097] This treatment step can be carried out before, after, or both before and after the cutting step.

[0098] The paper substrate produced in step (a) above can be shaped in step (b) above, which can be crimping, embossing, folding, compressing, or any combination thereof, in a direction perpendicular to the cylindrical axis of the filter for the smoking article or e-cigarette article.

[0099] Step (d) above can be any type of process known to those skilled in the art for bonding two substrates together: it can be a process of depositing one substrate onto the other, laminating the two substrates, or adhesively bonding the two substrates.

[0100] According to another particular embodiment, the method of the invention comprises the steps of: (a) producing the paper substrate by a wet laid process; (b) optionally shaping the paper substrate produced in step (a) above; (c11) producing a web from a natural fiber mixture, the natural fiber mixture comprising 85% to 95% by weight of cottonized flax fiber and 5% to 15% by weight of lyocell fiber, by a dry-laid method; (c21) introducing a binder into the web by spraying an aqueous binder dispersion, particularly comprising starch, onto the web; (c31) Dry the web obtained in step (c21) above to obtain a web having a surface area of ​​10 mg / cm 3 ~40mg / cm 3 obtaining a nonwoven substrate having a density of 85% to 98% by weight of the solid content of the nonwoven substrate, the natural fiber mixture being 85% to 98% by weight of the solid content of the nonwoven substrate, and the binder being 2% to 15% by weight of the solid content of the nonwoven substrate; (d) bonding the paper substrate produced in step (a) above or the paper substrate produced in step (b) above and the nonwoven substrate produced in step (c31) above to each other to produce a two-ply material; (e) forming a rod from the two-layer material produced in step (d) above; (f) wrapping the rod with a sheet of plug wrap paper; (g) adhesively bonding the sheets of plug wrap paper together to obtain a rod of filter material; (h) cutting the rod of filter material to produce a filter.

[0101] According to yet another particular embodiment, the method of the present invention comprises the steps of: (a) producing the paper substrate by a wet laid process; (b) optionally shaping the paper substrate produced in step (a) above; (c12) producing a web from softwood fluff pulp by an airlaid process; (c22) introducing a binder into the web by spraying an aqueous binder dispersion, particularly comprising starch, onto the web; (c32) The web obtained in step (c22) above is dried to obtain a web having a surface area of ​​20 mg / cm 3 ~45mg / cm 3 obtaining a nonwoven fabric substrate having a density of 85% to 95% by weight of the solid content of the nonwoven fabric substrate, the softwood fluff pulp occupying 85% to 95% by weight of the solid content of the nonwoven fabric substrate, and the binder occupying 5% to 15% by weight of the solid content of the nonwoven fabric substrate; (d) bonding the paper substrate produced in step (a) above or the paper substrate produced in step (b) above and the nonwoven substrate produced in step (c31) above to each other to produce a two-ply material; (e) forming a rod from the two-layer material produced in step (d) above; (f) wrapping the rod with a sheet of plug wrap paper; (g) applying a line of adhesive to the joint of the sheet of plug wrap paper to obtain a rod of filter material; (h) cutting the rod of filter material to produce a filter.

[0102] The binder introduction in step (c21) above or in step (c22) above can be carried out by impregnation, such as by impregnation with a size press, by spraying, such as by spraying with a spray device, by surface application, such as by coating or printing, in particular by spraying with a spray device. Advantageously, the spraying of the aqueous binder dispersion is carried out on both sides of the web.

[0103] The aqueous dispersion of the binder can be obtained by any technique known to those skilled in the art, who will know how to adjust the concentration of the binder in the aqueous dispersion to obtain the desired content of the binder in the nonwoven substrate of the present invention.

[0104] The drying of the web in the above step (c31) or the above step (c32) can be carried out by, for example, a drying device such as an air tunnel or an infrared lamp.

[0105] The web drying in the above step (c31) or in the above step (c32) can be carried out at a temperature between 75° C. and 200° C., in particular between 90° C. and 150° C., more particularly between 100° C. and 120° C. A temperature within the above range advantageously allows to minimize the carrying out time of the web drying step (c31) or (c32), while at the same time minimizing the degradation of the natural fibers of the nonwoven substrate, thus optimizing the manufacturing method of the invention.

[0106] Advantageously, the combination of the above step (c21) and the above step (c31), or the above step (c22) and the above step (c32), can enhance the cohesion of the natural fibers, and thus strengthen the structure of the nonwoven substrate of the two-layer material of the present invention.

[0107] The above step (c) in the method of the present invention may in particular comprise a step between the above step (c11) and the above step (c21), between the above step (c21) and the above step (c31), between the above step (c12) and the above step (c22), or between the above step (c22) and the above step (c32) of compressing the web to obtain a compressed web, which is then subjected to the above step (c21) or the above step (c22). This compression step makes it possible to reduce the thickness of the web in order to control the density of the nonwoven substrate.

[0108] Working Example

[0109] Example 1: Preparation of a two-layer material

[0110] Example 1.1: Two-ply material containing a paper substrate and a nonwoven substrate produced by an airlaid process

[0111] The paper substrate was produced by the wet-laid method. The paper substrate had a weight of 356 g / cm 3 Density, thickness of 101μm, and 36g / m 2 The sheet has a basis weight of 1.0 g.

[0112] A web was produced from softwood fluff pulp by the airlaid process. A solution containing 0.7% solids of starch (Perfectafilm X115, manufactured by Avebe) was sprayed onto both sides of the web. The web onto which the starch-containing solution had been sprayed was then dried at a temperature of 180°C to 190°C using infrared radiation and a hot air oven. In the resulting nonwoven fabric substrate, the softwood fluff pulp accounted for 85% by weight of the solids of the nonwoven fabric substrate, and the starch accounted for 15% by weight of the solids of the nonwoven fabric substrate. The resulting nonwoven fabric substrate had a density of 24 g / cm. 3 Density: 1910μm thickness, 46g / m 2 The sheet has a basis weight of 1.0 g.

[0113] The paper substrate was crimped and then deposited onto the nonwoven substrate to produce a two-ply material with a 50:50 weight ratio of paper substrate:nonwoven substrate.

[0114] Example 1.2: Two-ply material containing a paper substrate and a nonwoven substrate produced by a drylaid process

[0115] The paper substrate is the same as that in Example 1.1.

[0116] A web was produced from cottonized flax fibers (VERVAEKE FIBRE NV, length 22 mm) and lyocell fibers (LENZIG, 1.7 dtex / length 38 mm) by the drylaid method. The cottonized flax fibers and lyocell fibers were mixed, opened by a card to be parallel, and then deposited on a web-forming fabric. A solution containing 5% solids of starch (Perfectafilm X115, Avebe) was sprayed on both sides of the web. The web sprayed with the starch-containing solution was then dried in a hot air oven at a temperature of 100°C to 120°C. In the obtained nonwoven fabric substrate, the mixture of cotton-like flax fibers and lyocell fibers accounted for 92% of the solids of the nonwoven fabric substrate (90% cotton-like flax / 10% solids of the fiber mixture), and starch accounted for 8% of the solids of the nonwoven fabric substrate. The obtained nonwoven fabric substrate had a density of 12 g / cm 3 Density: 2140μm thickness and 26.2g / m 2The sheet has a basis weight of 1.0 g.

[0117] The paper substrate was crimped and then deposited onto the nonwoven substrate to produce a two-ply material with a 50:50 weight ratio of paper substrate:nonwoven substrate.

[0118] Example 2: Production and Characterization of Filters for Smoking Articles

[0119] The bi-ply material of Example 1.1 or Example 1.2 was used to manufacture smoking article filters using standard filter manufacturing techniques. Non-porous plug wrap paper was used to wrap the rod of filter material.

[0120] The filters of the present invention were compared with filters having the two-ply material or nonwoven substrate of Example 1.1, filters having the two-ply material or nonwoven substrate of Example 1.2, a paper substrate filter (crimped paper filter), and a commercially available cellulose acetate substrate filter. The crimped paper filter was manufactured using a standard method of manufacturing filters by crimping the paper substrate of Example 1.1. Each filter was cut into 21 mm sticks.

[0121] The characteristics of each filter are shown in Table 1 below.

[0122] Resistance to crushing (crush resistance) was measured using a Filtrona DHT200 device. During the measurement, the filters were crushed with a 300 g weight for 15 seconds. The amount of crushing (mm) was measured electronically.

[0123] [Table 1]

[0124] According to Table 1, the filters with the two-ply material of the present invention have superior crush resistance compared to filters with only a nonwoven substrate, which indicates that the combination of a dry-laid nonwoven substrate and a paper substrate improves crush resistance compared to filters with only a dry-laid nonwoven substrate.

[0125] Example 3: Cigarette production and characterization

[0126] Cigarettes were made using the filter described in Example 2. To make the cigarettes, the filter was attached to a tobacco rod using tipping paper. The tobacco rod was formed using a commercially available "American Blend" tobacco. The cigarettes were made to have a pressure drop similar to that of the commercially available cigarettes. The cigarettes were blocked from ventilation.

[0127] The prepared cigarettes were smoked in a Borgwaldt RM20 smoking machine according to standard ISO 3308:2000. Pressure drop ("PD" in Table 2) was measured according to standard ISO 6565:2002. Nicotine content in the smoke was measured according to standard ISO 10315:2000. The smoking results are shown in Table 2 below.

[0128] [Table 2]

[0129] Table 2 shows that at comparable pressure drops, the nicotine content in the smoke produced by cigarettes with filters having a two-ply material according to the present invention, cigarettes with a commercially available cellulose acetate filter, and cigarettes with filters having a nonwoven substrate was comparable. In particular, the filters of these cigarettes exhibited comparable nicotine retention capabilities.

[0130] Table 2 also shows that at comparable pressure drops, the nicotine content in the smoke produced by cigarettes with crimped paper filters was much lower than the nicotine content in the smoke produced by cigarettes with commercial cellulose acetate filters. In particular, the crimped paper filters exhibited a much greater nicotine retention capacity than the commercial cellulose acetate filters.

[0131] Thus, this Example 3 demonstrates that the user experience provided by a cigarette with a filter having a two-ply material according to the present invention is comparable to the user experience provided by a cigarette with a commercially available cellulose acetate filter.

Claims

1. 1. A filter comprising two layers of material, 500 mg / cm ３ ~200 mg / cm ３ a paper substrate having a density of 7 mg / cm ３ ~60 mg / cm ３ and a nonwoven substrate having a density of

2. 2. The filter of claim 1, A filter, wherein the mass ratio of the paper substrate to the nonwoven fabric substrate is 10:90 to 90:

10.

3. 3. A filter according to claim 1 or 2, The filter, wherein the paper substrate has a thickness of 50 μm to 200 μm.

4. 3. A filter according to claim 1 or 2, The nonwoven fabric substrate has a thickness of 700 μm to 6000 μm.

5. 2. The filter of claim 1, The filter, wherein the nonwoven substrate comprises natural fibers selected from wood fibers, leaf fibers, fruit fibers, seed fibers, bast fibers, stem fibers, reed fibers, and any combination thereof.

6. 2. The filter of claim 1, The filter, wherein the nonwoven substrate is consolidated by chemical consolidation, needling, hydroentanglement, or any combination thereof.

7. 2. The filter of claim 1, The nonwoven fabric substrate may be obtained by a dry-laid or air-laid method.

8. 10. The filter of claim 1 for a smoking article or an e-cigarette article.

9. A smoking article comprising the filter according to claim 8.

10. An electronic cigarette article comprising the filter of claim 8.

11. 9. A method for manufacturing a filter for a smoking article or an electronic cigarette article according to claim 8, comprising: (a) producing the paper substrate by a wet-laid process; (b) optionally shaping the paper substrate produced in step (a); (c) manufacturing the nonwoven substrate by a dry-laid or air-laid process; (d) bonding the paper substrate produced in step (a) or step (b) and the nonwoven substrate produced in step (c) together to form a two-layer material; (e) forming a rod from the two-layer material produced in step (d); (f) wrapping the rod in a sheet of plug wrap paper; (g) adhesively bonding the sheets of plug wrap paper together to obtain a rod of filter material; (h) cutting the rod of filter material to produce a filter.