Structured filtration material for nicotine delivery products

Abstract

The present application describes a filter material for manufacturing a nicotine delivery product, the filter material being hydroentangled and comprising at least 50% and at most 100% of cellulose fibers relative to the mass of the filter material, wherein the filter material has a basis weight of at least 25 g / m 2 and at most 60 g / m 2 and wherein the filter material has a structure characterized in that it ensures that the filter material has a transparency of at least 45% and at most 70% measured according to DIN 53147:1993-01. Furthermore, the present application also describes a portion of a nicotine delivery product, the portion comprising a filter material; a smoking article comprising such a portion; an oral nicotine delivery product; and a method of manufacturing a filter material.

Description

Technical Field

[0001] This application relates to filter materials for nicotine delivery products, portions of smoking articles made therefrom, or oral nicotine delivery products made therefrom, wherein the filter material has a structure that provides advantageous properties for the nicotine delivery product, such as relative hardness, draw resistance, filtration efficiency, optical appearance, or biodegradability. Thus, a structural feature of the filter material is its transparency. Background Technology

[0002] Nicotine delivery products can be smoking articles. Smoking articles are typically rod-shaped articles consisting of at least two rod-shaped portions arranged close to each other. One portion contains a material capable of forming an aerosol upon heating, and at least one other portion contains a material for influencing the properties of the aerosol.

[0003] A smoking product can be a filtered cigarette, wherein the first part contains materials that form an aerosol, particularly tobacco leaves, and other parts that form a filter and are used to filter the aerosol. Here, the aerosol is generated by burning the materials that form the aerosol, and the filter is used to filter the aerosol and provide a defined draw resistance for the filtered cigarette.

[0004] Smoking products can also be so-called heated tobacco products, in which the aerosol-forming materials are heated but not burned. This reduces the quantity and amount of harmful substances in the aerosol. Such smoking products also consist of at least two parts, but often more, particularly four. One part contains the aerosol-forming materials, which typically include tobacco leaves, reconstituted tobacco leaves, tobacco leaves processed by other methods, or nicotine and glycerin or propylene glycol. Furthermore, in some cases, optional portions of heated tobacco products are used to transfer, cool, or filter the aerosol.

[0005] Some are usually wrapped with wrapping material. Paper is commonly used as the wrapping material.

[0006] In the following text, unless otherwise expressly stated or can be directly derived from the context, the term "part" shall be understood as a portion of a smoking article that does not contain materials that form aerosols, but such as those used for transferring, cooling or filtering aerosols.

[0007] In the prior art, it is known to form such portions from cellulose acetate or polylactic acid. Since cellulose acetate and polylactic acid biodegrade very slowly in the environment, the industry is interested in manufacturing portions of smoking products from other materials with better biodegradability. In the prior art, it is known to manufacture portions of smoking products from paper, particularly filter portions. Generally, these portions are well biodegradable, but some drawbacks exist. For example, filter portions produced from paper typically have high filtration efficiency, thus resulting in a dry aerosol, which impairs the aerosol flavor compared to cigarettes with conventional filter portions produced from cellulose acetate. Furthermore, they generally have lower filtration efficiency for phenol compared to cellulose acetate. Additionally, it has been shown that manufacturing consumer-acceptable portions from paper is difficult in terms of the combination of draw resistance, filtration efficiency, and stiffness. To reduce filtration efficiency, less paper is often used, and the portion becomes soft and has low draw resistance.

[0008] However, another reason why paper-based filter portions have not been widely used lies in their optical appearance. In the mouthpiece of smoking products, the cut surface of the portion located at the mouthpiece is usually visible, and for the conventional portion produced from cellulose acetate, consumers are accustomed to a uniform white surface where individual cut fibers are barely discernible. However, paper-based portions have a rougher structure, which obviously conveys an impression of lower quality to consumers. Therefore, in filters composed of several portions, the paper-based portion is often used only as one part, so the cut surface is not visible to the consumer. Consequently, the portion located at the mouthpiece is still frequently produced from cellulose acetate. Due to these optical defects, the biodegradability advantage of paper-based portions cannot be fully utilized.

[0009] Nicotine delivery products can also be oral nicotine delivery products. Oral nicotine delivery products are typically small pouches made of a nonwoven material containing nicotine-containing materials, such as tobacco leaves. During use, the consumer holds the pouch in their mouth for a period of time, after which the substance, particularly nicotine, is released from the nicotine-containing material. However, the nonwoven materials that make up the pouches often contain plastic and are therefore non-biodegradable. Examples of oral nicotine delivery products are products packaged in pouches, such as Swedish snus, white snus, or other smokeless tobacco products. Oral nicotine delivery products without tobacco leaves are also known.

[0010] Therefore, the industry is interested in obtaining filter materials that allow the manufacture of portions of smoking articles having a favorable combination of filtration efficiency, draw resistance, stiffness and optical appearance, or that allow the manufacture of nicotine delivery products with good biodegradability. Summary of the Invention

[0011] The purpose of this application is to provide a filter material for smoking articles that enables the manufacture of a portion that is as similar as possible to conventional portions produced from cellulose acetate in terms of hardness, draw resistance, filtration efficiency, and optical appearance, but is also well biodegradable.

[0012] Another objective of this application is to provide a filter material from which oral nicotine delivery products can be manufactured, and from which better biodegradability can be achieved.

[0013] These objectives are achieved through the filter material described in this application, the method for manufacturing the filter material described in this application, a portion of the smoking article described in this application, the smoking article described in this application, and the oral nicotine delivery product described in this application.

[0014] The inventors have discovered that these objectives can be achieved by a filter material that is hydroentangled and contains at least 50% and at most 100% cellulose fibers relative to the mass of the filter material, and wherein the filter material has a reference weight of at least 25 g / m² and at most 60 g / m², and wherein the filter material has a structural feature in that it provides the filter material with at least 45% and at most 70% transparency as measured according to DIN 53147:1993-01.

[0015] According to the invention, the filter material is manufactured by hydroentangling. This manufacturing method provides the filter material with characteristic properties that distinguish it from other filter materials, and especially from paper, and which cannot be obtained in the same way by other manufacturing methods. Compared to, for example, paper in which strength is mainly due to hydrogen bonding and fibers are mainly arranged in the plane of the paper, the strength of the hydroentangled nonwoven fabric is achieved through the entanglement of fibers, and therefore a considerable proportion of the fibers are also oriented in the thickness direction of the nonwoven fabric. This arrangement of fibers is particularly necessary, giving the portions manufactured from it advantageous properties in terms of suction resistance, filtration efficiency, and stiffness.

[0016] The inventors have discovered that portions of spunlace filter materials derived from compositions according to the invention generally possess better properties than those derived from paper, but it is still possible to further optimize these properties and bring them even closer to those derived from cellulose acetate. Similar to portions derived from paper, but to a lesser extent, a problem arises because only a small amount of filter material can be used to achieve good filtration efficiency, and therefore partial draw resistance, and in particular, stiffness, cannot fully meet consumer expectations. According to the inventors' findings, the special structure of the filter material can solve this problem. The inventors have recognized that it is advantageous for the filter material to have a variety of irregularities in thickness or reference weight distributed across its entire surface, rather than having a nearly uniform surface like paper or plastic film. These irregularities can, for example, be pores or thin spots arranged regularly or irregularly on the filter material. In this respect, according to the inventors' findings, it is advantageous that the pores or thin spots are not created by removing material, but rather entirely or partially by altering the redistribution and arrangement of fibers within the filter material. This can be achieved by the manufacturing method according to the invention explained below.

[0017] In this respect, the precise shape and arrangement of the irregularities are not important, but they must be distributed approximately uniformly on the surface and must exceed a certain size. To characterize these irregularities, and especially their dimensions, the inventors have considered various parameters such as thickness, reference weight, or breathability. However, it has been found that these parameters cannot be measured with sufficiently low spatial resolution to capture the irregularities.

[0018] However, the inventors have recognized that the transparency of a filter material is altered by the redistribution of fibers. In other words, the special structure that distinguishes the filter material according to the invention provides a characteristic of higher transparency, thereby differentiating it from filter materials of the same reference weight and similar composition but with conventional structures. In this respect, transparency is a suitable, well-defined, and measurable parameter that can be used to characterize the desired structure of the filter material.

[0019] In this respect, the observed increase in transparency of filter materials with the desired structure is surprising, because the redistribution of fibers does indeed expect to make the pores or thin spots more transparent, but the areas between the pores and thin spots where more fibers are present will become less transparent, so overall, on average, the effect on transparency is small or nonexistent. However, in reality, experiments have shown that filter materials with conventional structures, even at the lowest baseline weight of 25 g / m² according to the invention, have a transparency of no more than 40% according to DIN 53147:1993-01. Only the redistribution of fibers can achieve higher transparency, and this is directly related to the pores and thin spots derived from the redistribution of the fiber structure of the filter material; this also brings advantages according to the invention in terms of stiffness and suction resistance from the parts from which it is manufactured.

[0020] According to the inventors' findings, cellulose fibers are necessary to provide sufficient strength to the filter material so that it can be processed into portions. According to the invention, the proportion of cellulose fibers in the filter material is at least 50% and at most 100% of the mass of the filter material, however, preferably at least 60% and at most 100% relative to the mass of the filter material, and particularly preferably at least 70% and at most 95%.

[0021] Cellulose fibers can be pulp fibers or fibers derived from regenerated cellulose, or a mixture thereof.

[0022] The pulp fibers are preferably derived from coniferous, deciduous, or other plants such as flax, jute, ramie, kenaf, kapok, coconut, Manila hemp, sisal, bamboo, cotton, or Spanish grass. Additionally, mixtures of pulp fibers from various sources can be used to manufacture spunlace filter media. Particularly preferred are pulp fibers derived from coniferous wood, as such fibers provide good strength to the filter media even in smaller proportions.

[0023] The filter material according to the invention may contain fibers derived from regenerated cellulose. Preferably, the proportion of fibers derived from regenerated cellulose is at least 5% and at most 50% relative to the mass of the filter material, particularly preferably at least 10% and at most 45%, and especially at least 15% and at most 40%.

[0024] The fibers derived from regenerated cellulose are preferably viscose fibers, modal fibers, or Lyocell fibers. ® Tencel ®Or a mixture thereof. These fibers have good biodegradability and can be used to optimize the strength of filter materials and adjust the filtration efficiency of parts made from them for smoking products. Due to their production methods, they exhibit less variation than pulp fibers derived from natural sources, and therefore contribute to less variation in the properties of parts made from filter materials compared to the case of using pulp fibers alone.

[0025] According to the invention, the reference weight of the filter material is at least 25 g / m² and at most 60 g / m², preferably at least 28 g / m² and at most 55 g / m², and particularly preferably at least 30 g / m² and at most 55 g / m². The reference weight affects the tensile strength of the filter material, wherein a higher reference weight results in higher strength. This value refers to the reference weight measured according to ISO 536:2012.

[0026] According to the present invention, the transparency of the filter material, measured according to DIN 53147:1993-01, is at least 45% and at most 70%, preferably at least 50% and at most 66%. In addition to the at least 45% transparency due to fiber redistribution, it also exhibits a positive effect on the stiffness and suction resistance of the portion manufactured from the filter material. However, the transparency should not be too high, as this would cause thin spots and pores to dominate, to a degree that makes the strength of the filter material unsuitable for the portion manufactured from it.

[0027] In fact, the shape and size of irregularities cannot be precisely specified because they cannot be precisely defined relative to the surrounding filter material; however, it is clear that each individual irregularity must be much smaller than the area of ​​filter material required to manufacture the portion. Because the special structure of the filter material is also formed by pores, the area of ​​most pores, for example, more than 90% of the pores, is preferably less than 10 mm². At these scales, transparency is particularly suitable as a parameter characterizing the structure of the filter material, since the measurement area for transparency according to DIN 53147:1993-01 is approximately 2.5 cm², and therefore typically includes the pores or thin spots and the surrounding area. Embodiments illustrating these irregularities are shown by way of examples. Figure 2 The details are explained below. However, the invention is not limited to having... Figure 2 The irregular shape of the geometric structure shown.

[0028] For adjusting specific properties, the filter material according to the invention may contain additives such as alkyl ketene dimers (AKD), alkenyl succinic anhydride (ASA), fatty acids, starch, starch derivatives, carboxymethyl cellulose, alginate, wet strength agents, or substances for adjusting pH, such as, for example, organic or inorganic acids or bases. As additives, the filter material according to the invention may also contain one or more combustion additives selected from citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxalates, salicylates, α-hydroxyoctanoates, phosphates, polyphosphates, chlorides, and bicarbonates, and mixtures thereof, and particularly preferably selected from trisodium citrate, tripotassium citrate, and mixtures thereof.

[0029] The technician will be able to determine the type and amount of such additives based on his experience.

[0030] The filter material according to the invention may also contain other substances that make the filter material more efficient than cellulose acetate. In a preferred embodiment of the filter material according to the invention, the filter material comprises a substance selected from glyceryl triacetate, propylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, and triethyl citrate, or a mixture thereof.

[0031] The thickness of the filter material, measured according to ISO 534:2011, is at least 70 µm and at most 1000 µm, preferably at least 100 µm and at most 800 µm, and particularly preferably at least 150 µm and at most 750 µm. The thickness affects the amount of filter material that can be incorporated into a portion of a smoking article, and thus affects the draw resistance and filtration efficiency of the portion, as well as the processability of the filter material, since the filter material is often rolled or folded for manufacturing portions of smoking articles. For such process steps, excessive thickness is disadvantageous, and employing preferred and particularly preferred thickness intervals allows for particularly good processability of the filter material according to the invention in order to form portions of smoking articles.

[0032] The mechanical properties of the filter material are important for processing the filter material according to the invention into nicotine delivery products. In particular, pores or thin spots should not excessively reduce the strength of the filter material. The tensile strength relative to the width of the filter material, as measured according to ISO 1924-2:2008, is preferably at least 0.05 kN / m and at most 5 kN / m, particularly preferably at least 0.07 kN / m and at most 4 kN / m.

[0033] The elongation at break of the filter material is important because during the processing of the filter material according to the invention into a nicotine delivery product, the filter material is typically stretched or compressed in the direction of operation, and therefore a particularly high elongation at break is beneficial. Therefore, the elongation at break of the filter material, as measured according to ISO 1924-2:2008, is preferably at least 1% and at most 50%, and particularly preferably at least 3% and at most 40%.

[0034] Tensile strength and elongation at break can depend on the orientation of the sample taken from the filter material for measurement. The aforementioned characteristics of the filter material are satisfied when the tensile strength or elongation at break is positioned at a preferred or particularly preferred interval in at least one direction.

[0035] Parts of a smoking article can be manufactured from the filter material of the present invention using methods known in the art. These methods include, for example, curling or folding the filter material, forming a continuous rod from the curled or folded filter material, wrapping the continuous rod with a wrapping material, and cutting the wrapped rod into individual rods of defined lengths. In many cases, the length of such a rod is an integer multiple of the length of the part subsequently used in the smoking article according to the present invention, and therefore the rod is then cut into portions of the desired length before or during the manufacture of the smoking article.

[0036] A portion of the smoking article according to the invention includes the filter material and the wrapping material according to the invention.

[0037] In a preferred embodiment of the part according to the invention, the part is cylindrical with a diameter of at least 3 mm and at most 10 mm, particularly preferably at least 4 mm and at most 9 mm, and even more particularly preferably at least 5 mm and at most 8 mm. These diameters are advantageous for the application of the part according to the invention in smoking articles.

[0038] In a preferred embodiment of the invention, the portion has a length of at least 4 mm and at most 40 mm, particularly preferably at least 6 mm and at most 35 mm, and especially at least 10 mm and at most 28 mm.

[0039] The partial draw resistance, in particular, determines the pressure differential that a smoker must apply during the consumption of a smoking product to achieve a certain volumetric flow rate, and therefore fundamentally affects the smoker's acceptance of the product. Partial draw resistance can be measured according to ISO 6565:2015 and given in millimeters of water (mmWG). As a very good approximation, partial draw resistance is proportional to the length of the draw resistance; therefore, the measurement can also be performed on a rod that differs from the partial draw resistance only in its length. The partial draw resistance can thus be easily calculated.

[0040] The partial suction resistance per unit length is preferably at least 1 mm WG / mm and at most 12 mm WG / mm, and particularly preferably at least 2 mm WG / mm and at most 10 mm WG / mm.

[0041] The wrapping material according to the present invention is preferably paper or film.

[0042] The wrapping material according to the invention preferably has a reference weight of at least 20 g / m² and at most 150 g / m², particularly preferably at least 30 g / m² and at most 130 g / m². The wrapping material having this preferred or particularly preferred reference weight provides a particularly advantageous rigidity to the portion of the smoking article thus wrapped. This means that the smoker cannot accidentally compress the portion located inside the smoking article.

[0043] Smoking articles according to the invention can be manufactured from parts thereof using methods known in the art.

[0044] The smoking article according to the invention comprises a portion containing a material that forms an aerosol and a portion comprising a filter material and a wrapping material according to the invention.

[0045] Since the cut surface of the portion according to the invention is generally very similar to that of the portion from cellulose acetate, in a preferred embodiment, the portion of the smoking article located next to the mouth end is the portion according to the invention.

[0046] In a preferred embodiment, the smoking product is a filtered cigarette, and the material that generates the aerosol includes tobacco leaves.

[0047] In a preferred embodiment, the smoking article is one in which the material forming the aerosol is heated but not burned during the intended use, and the material generating the aerosol includes tobacco leaves, reconstituted tobacco leaves, nicotine, glycerin, propylene glycol, or a mixture thereof.

[0048] The transparency resulting from the special structure of the filter material allows for further advantages. Some smoking articles are constructed so that the smoker can see the interior of the smoking article. For such smoking articles, the wrapping material is partially transparent or provides pores that allow direct observation of the filter material. However, due to their low transparency, it is not possible to further understand filters known in the art. If the filter material according to the invention has more than 50% transparency, then, for example, it may be possible to identify a fragile capsule filled with flavoring located in the filter. In a particularly preferred embodiment of the smoking article, the smoking article thus comprises a portion containing a material that forms an aerosol and a portion comprising the filter material and the wrapping material of the invention, wherein the wrapping material is at least partially transparent or has pores, and the filter material has at least 50% transparency as measured according to DIN 53147:1993-01.

[0049] The inventors have unexpectedly discovered that the filter material is also suitable for oral nicotine delivery products. The inventors have found that the filter material according to the invention exhibits good biodegradability due to its composition and special structure, is characterized by its transparency, and during use, it also has good permeability to substances released from nicotine-containing materials in oral nicotine delivery products, thus making it particularly suitable for use in nicotine delivery products.

[0050] The oral nicotine delivery product according to the invention therefore comprises a pouch formed of the filter material according to the invention and containing a nicotine-containing material. Preferably, the filter material has a transparency of at least 50% and at most 70% as measured according to DIN 53147:1993-01.

[0051] Materials containing nicotine are preferably tobacco leaves.

[0052] The filter material according to the invention can be manufactured by the following method, which includes steps A to D.

[0053] A – Provides a fiber web including cellulose fibers. B – Hydroentangling the fiber web by directing at least one water jet onto the web to produce a hydroentangled fiber web. C – Creates a structure within the spunlace fiber web. D – Dried spunlace fiber web, The amount of cellulose fiber selected in step A is such that, after drying in step D, the filter material contains at least 50% and at most 100% cellulose fiber relative to its mass. After drying in step D, the filter material has a reference weight of at least 25 g / m² and at most 60 g / m², and After drying in step D, the filter material is structurally characterized by providing a transparency of at least 45% and at most 70% as measured according to DIN 53147:1993-01, and The structure in step C is generated by directing at least one water jet onto the fiber web while supporting the fiber web with a surface having multiple protrusions.

[0054] In step C, at least one water jet directed onto the fiber web causes a redistribution of the fibers, causing them to arrange themselves around and be displaced by the protrusions. Thus, the protrusions create pores or thin spots, depending on the pressure of the water jets and the amount of fibers initially present in the protrusion region. This structure provides the filter material with the characteristic increased transparency described earlier. However, typically, the shape of the protrusions is only imprecisely transferred to the fiber web; therefore, even if all the protrusions have the same shape, the pores or thin spots in the fiber web and filter material are irregular in shape and size. Nevertheless, the increase in transparency can be reliably demonstrated. Thinner spots, and especially pores, can also be produced essentially by embossing or die-cutting, but in that case, the fibers are compressed or cut and not arranged differently. However, by the method according to the invention described herein, the fibers are arranged around the pores or thin spots, thereby creating a mesh structure. Compared to filter materials with a nearly uniform surface or those produced by embossing or die-cutting, this mesh structure results in greater stiffness from the portion from which it is manufactured and lower suction resistance for a given material.

[0055] Filter materials manufactured according to this method should be suitable for nicotine delivery products. This means that they can, in particular, possess all the characteristics described above in conjunction with the filter material, either individually or in combination.

[0056] In a preferred embodiment of the method according to the invention, providing the fiber web in step A comprises spinning a plurality of cellulose fibers, wherein the cellulose fibers are formed from filaments of regenerated cellulose, and wherein, after drying in step D, at least 90% by mass of the filter material is formed from the filaments of regenerated cellulose. In a particularly preferred embodiment of the method, the filaments of regenerated cellulose are Lyocell. ® .

[0057] In another preferred embodiment of the method according to the invention, providing the fiber web in step A includes the following steps A1 to A4.

[0058] A1 – produces an aqueous suspension containing cellulose fibers. A2 – Apply the suspension from step A to the operating line. A3 – The suspension is dehydrated via a running wire to form a fiber web. A4 – Transfer the fiber mesh from step A3 onto the support wire.

[0059] In a preferred embodiment of the method according to the invention, the aqueous suspension in step A1 has a solids content of up to 3.0%, particularly preferably up to 1.0%, and even more preferably up to 0.2%, and especially up to 0.05%. The particularly low solids content of the suspension enables the formation of a low-density fiber web in step A3, which is beneficial to the filtration efficiency of the portion from which it is manufactured.

[0060] In a preferred embodiment of the method according to the invention, the running lines in steps A2 and A3 are inclined upward at an angle of at least 3° and at most 40° relative to the horizontal direction of the fiber web, particularly preferably at least 5° and at most 30°, and more particularly preferably at least 15° and at most 25°.

[0061] In a preferred embodiment, the method includes the step of creating a pressure difference between the two sides of the running line to support the dehydration of the suspension in step A3, wherein the pressure difference is particularly preferably created by a vacuum chamber or a suitably shaped wing.

[0062] In a preferred embodiment of the method according to the invention, a plurality of water jets are used to perform hydroentangling in step B, wherein the water jets are arranged laterally in at least one row relative to the running direction of the fiber web.

[0063] In a preferred embodiment of the method according to the invention, the hydroentangling in step B is performed by at least two water jets directed onto the fiber web, wherein, particularly preferably, the at least two water jets act on different sides of the fiber web.

[0064] In a preferred embodiment of the method according to the invention, the fiber web in step C is supported by cylinders with a plurality of protrusions positioned on their surface.

[0065] Preferably, the area of ​​each protrusion projected onto the surface of the fiber web in the supporting step C is at least 0.1 mm² and at most 15 mm², particularly preferably at least 0.25 mm² and at most 10 mm².

[0066] In a preferred embodiment of the method according to the invention, the method includes additional steps in which one or more additives are applied to the fiber web. The additives are preferably selected from: alkyl ketene dimers (AKD), alkenyl succinic anhydride (ASA), fatty acids, starch, starch derivatives, carboxymethyl cellulose, alginate, wet strength agents, substances for pH adjustment, such as, for example, organic or inorganic acids or bases, and mixtures thereof; or the additive is a combustion additive selected from citrate, malate, tartrate, acetate, nitrate, succinate, fumarate, gluconate, glycolate, lactate, oxalate, salicylate, α-hydroxyoctanoate, phosphate, polyphosphate, chloride, and bicarbonate, and mixtures thereof.

[0067] In a preferred embodiment of the method according to the invention, the application of one or more additives is performed between steps C and D of the method according to the invention. In another preferred embodiment of the method according to the invention, the application of one or more additives is performed after step D, followed by another step for drying the fiber web.

[0068] In a preferred embodiment of the method according to the invention, the drying in step D is carried out at least in part by contact with hot air, by infrared radiation, or by microwave radiation. Drying by direct contact with a heated surface is also possible, but not preferred, because this may reduce the thickness of the spunlace filter material.

[0069] In other methods, the filter material according to the invention can also be manufactured via steps A, B, and D. Step C is omitted here, making the method not according to the invention. In step B, a high pressure is selected for some of the water jets, causing the water jets to create pores or thin spots in the fiber web supported by support lines. For filter materials manufactured by this method, irregularities can be spatially much smaller, so that the filter material is according to the invention only if the machine settings, such as the pressure of the water jets, are selected such that the transparency of the filter material is at least 45% and at most 70%. Attached Figure Description

[0070] Figure 1 The diagram shows an arrangement in which the method for manufacturing spunlace filter material according to the present invention can be carried out.

[0071] Figure 2 The examples illustrate filter materials according to the invention and those not according to the invention. Detailed Implementation

[0072] The following will describe filter materials, methods for manufacturing filter materials, components of smoking articles, and some preferred embodiments of smoking articles. Furthermore, comparative embodiments not based on the invention are described.

[0073] For the manufacture of filter materials, the following methods were used: Figure 1 The arrangement shown.

[0074] In step A1, a suspension 1 of pulp fibers and fibers from regenerated cellulose is provided in storage tank 2 and pumped from there onto running line 3, inclined upward relative to the horizontal, step A2, and dehydrated through vacuum chamber 9, step A3, thereby forming a fiber web 4 on the line, the overall direction of movement of which is indicated by arrow 10. The fiber web 4 is removed from line 3 and transferred to a support line 5, which is also running, step A4. There, water jets 11, arranged in several rows laterally relative to the running direction of the fiber web 4, are directed from device 6 onto the fiber web 4 to wind the fibers and solidify the fiber web 4 into a nonwoven fabric, step B. In another step, water jets 12 are also directed onto the other side of the fiber web 4 through another device 7, where the fiber web 4 is supported by a cylindrical spool 13 with multiple protrusions already formed on its surface, step C. Next, the still damp nonwoven fabric runs through drying device 8 and is dried there, step D, to obtain filter material.

[0075] Exemplary Example 1

[0076] To manufacture the spunlace filter material, pulp fibers from coniferous wood and Lyocell are used. ® A blend of fibers, wherein the amount of fibers is selected such that the final filter material consists of 65% pulp fibers and 35% Lyocell. ® Fiber composition. The final filter material has a base weight of 55 g / m² and a thickness of 330 µm.

[0077] In step C of the manufacturing method, a water jet is produced— Figure 1 12 in the middle is directed onto fiber web 4, and fiber web 4 is made of a spool— Figure 1 The scroll has 13 supports. The scroll has prismatic protrusions arranged close together. Figure 1 (Not shown in the image), which has a square base of 1 mm × 1 mm. The protrusions are arranged in rows, with a distance of 1 mm between adjacent rows and between protrusions in each row.

[0078] The protrusions and water jets create thin spots in the filter material, but also pores, giving the filter material an overall irregular structure. The transparency of the filter material was measured at several randomly selected locations according to DIN 53147:1993-01, yielding a value of 49.1% with a standard deviation of 0.76% (absolute). Figure 2 The filter material of Exemplary Example 1 is shown, denoted by 1, wherein the length of line 4 is approximately 1 cm.

[0079] Exemplary Example 2

[0080] To manufacture the spunlace filter material, a mixture of pulp and viscose fibers from coniferous wood is used, wherein the fiber amounts are selected such that the final filter material consists of 80% pulp fibers and 20% viscose fibers. The final filter material has a reference weight of 50 g / m² and a thickness of 290 µm.

[0081] In step C of the manufacturing method, a water jet is produced— Figure 1 12 is directed onto fiber web 4, and fiber web 4 is spun onto a reel— Figure 1 The 13 supports in the middle. Scroll— Figure 1 13 in the example is configured according to exemplary embodiment 1, but the water jet— Figure 1 The pressure of 12 in the middle was chosen to be higher.

[0082] The protrusions and the water jet created thin spots, but due to the higher pressure, more pores were produced than in the filter material of Exemplary Example 1. The transparency of the filter material was measured at several randomly selected locations according to DIN 53147:1993-01, and a value of 55.7% was obtained with a standard deviation of 1.62% (absolute). Figure 2 The filter material of Exemplary Example 2 is shown, denoted by 2, wherein the length of line 4 is approximately 1 cm.

[0083] Exemplary Example 3

[0084] To manufacture the spunlace filter material, the same fiber blend as in Exemplary Example 2 was used. The final filter material had a reference weight of 35 g / m² and a thickness of 200 µm.

[0085] Unlike the method according to the invention, step C is omitted, and the pressure of the water jet in step B is chosen to be very high, resulting in thin spots and pores in the filter material in a very irregular arrangement.

[0086] The transparency of the filter material was measured at several randomly selected locations according to DIN 53147:1993-01, and a value of 52.3% was obtained with a standard deviation of 2.47% (absolute). Figure 2 The filter material of exemplary embodiment 3 is shown, denoted by 3, wherein the length of line 4 is approximately 1 cm.

[0087] Comparative Example A

[0088] To manufacture a filter material not according to the invention, the same fiber mixture as in Exemplary Example 1 is used. However, the chosen baseline weight is particularly low, and only 25.8 g / m² in the final filter material.

[0089] The filter material is manufactured according to steps A, B, and D of the method according to the invention, but the generation of the structure in step C is omitted. The surface of the filter material is obviously much more uniform than the surfaces of exemplary embodiments 1 to 3.

[0090] The transparency of the filter material according to the invention was measured at several randomly selected locations according to DIN 53147:1993-01, and a value of 38.2% was obtained at a standard deviation of 0.53% (absolute). Figure 2 A filter material not according to a comparative embodiment of the invention is shown, denoted by A, wherein line 4 is approximately 1 cm in length.

[0091] Each filter material in Exemplary Embodiments 1 to 3 and the Comparative Embodiment is manufactured using a paper-wrapped filter rod, which is 100 mm long and 7.85 mm in diameter. The width of the filter material mesh and the machine settings in the filter manufacturing process are selected such that a similar draw resistance of 440 ± 15 mmWG is obtained for each filter rod. A 20 mm long section is cut from the filter rod, thereby producing an 83 mm long American blend cigarette without filter ventilation. The average weight of the cigarette is 932.7 mg. The cigarette is smoked according to the method specified in ISO 3308:2012, and the amount of nicotine-free dry particulate matter in each cigarette is determined. The filter portion of the cigarette is removed, and the amount of nicotine-free dry particulate matter contained in each filter portion is also determined, thereby calculating the filtration efficiency as a percentage, where the filtration efficiency represents the proportion of nicotine-free dry particulate matter retained in the filter in the inflow filter portion. Therefore, in addition to the characteristics of the filter material, the filtration efficiency also depends on the length and diameter of the filter portion.

[0092] The stiffness of the filter rod was measured using a DD60A measuring instrument from Borgwaldt KC. Here, the filter rod is exposed to a load of a test body with defined forces for a defined time, and the deformation is measured and expressed as a percentage relative to the undeformed state.

[0093] The suction resistance (PD) of the filter rod, the filtration efficiency (FE) for nicotine-free dry particulate matter, and the hardness (HD) of the filter section are shown in Table 1. Additionally, the transparency (TR) of the filter material according to DIN 53147:1993-01 is shown in Table 1. Data from the filter produced from cellulose acetate is presented in Comparative Example B, in addition to Exemplary Examples 1 to 3 and Comparative Example A. For Comparative Example B, since the filter material is not in the form of a fiber web, transparency could not be measured.

[0094]

[0095] Table 1

[0096] As can be seen from Table 1, under comparable suction resistance, the filtration efficiency of the portions from Exemplary Embodiments 1 to 3 is significantly closer to that of the cellulose acetate filter from Compemplary Embodiment B than that of the portion from Compemplary Embodiment A which is not based on the invention. Clearly, despite similar suction resistance, the mesh structure of Exemplary Embodiments 1-3 allows aerosols to flow through the portions more effectively, thereby filtering out less nicotine-free dry particulate matter from the aerosols. It can also be seen that this decrease in filtration efficiency is accompanied by an increase in transparency; therefore, transparency is indeed a suitable parameter characterizing the irregularity of the filter material and relating it to filtration efficiency.

[0097] The portions from exemplary embodiments 1-3 of the present invention have a slightly lower hardness than those from comparative embodiments A and B. This is not very significant, as such a small difference in hardness can be compensated for by selecting a harder wrapping material for the portion.

[0098] An optical appearance of the filter cross-section of a cigarette visible at the mouth end of exemplary embodiments 1-3, compared with a subjective comparison of the filter produced from cellulose acetate in Comparative Embodiment B, shows that they are only slightly different, and in this respect, in any case, are significantly more similar to Comparative Embodiment B than conventional paper filters.

[0099] Therefore, it has been shown that the filter materials manufactured according to the invention generally have properties in terms of suction resistance, filtration efficiency, hardness, and optical appearance that are closer to those of filters produced from cellulose acetate than filter materials produced from paper or spunlace filter materials not according to the invention. However, the filter materials according to the invention exhibit significantly better biodegradability than those produced from cellulose acetate.

[0100] An oral nicotine delivery product in the form of a pouch filled with the prepared tobacco leaves was manufactured from the filter material according to exemplary embodiment 2, wherein no difference was found in terms of use compared to conventional oral nicotine delivery products. However, the pouch has better biodegradability than conventional pouches.

Claims

1. A filter material for manufacturing nicotine delivery products, wherein the filter material is hydroentangled and contains at least 50% and at most 100% cellulose fibers relative to the mass of the filter material, wherein the filter material has a reference weight of at least 25 g / m² and at most 60 g / m², and wherein the filter material has a structure characterized in that it provides the filter material with at least 45% and at most 70% transparency as measured according to DIN 53147:1993-01.

2. The filter material of claim 1, wherein the proportion of cellulose fibers in the filter material is at least 70% and at most 95% relative to the mass of the filter material.

3. The filter material of claim 1 or 2, wherein the cellulose fiber is formed from pulp fiber, fiber from regenerated cellulose, or a mixture thereof.

4. The filter material of claim 3, wherein the pulp fiber is derived from coniferous wood, deciduous wood, flax, jute, ramie, kenaf, kapok, coconut, Manila hemp, sisal, bamboo, cotton, or Spanish grass, or is formed from a mixture of two or more pulp fibers from these sources.

5. The filter material of claim 3, wherein the proportion of fibers derived from regenerated cellulose is at least 15% and at most 40% relative to the mass of the filter material.

6. The filter material of claim 3, wherein the fiber derived from regenerated cellulose is viscose fiber, modal fiber, or Lyocell fiber. ® Tencel ® Or a mixture of the above.

7. The filter material as claimed in claim 1 or 2, wherein its reference weight according to ISO 536:2012 is at least 28 g / m² and at most 55 g / m².

8. The filter material as claimed in claim 1 or 2, wherein its transparency, as measured according to DIN 53147:1993-01, is at least 50% and at most 66%.

9. The filter material of claim 1 or 2, wherein the structure comprises a plurality of pores in the filter material, wherein at least 90% of the pores have an area of ​​less than 10 mm².

10. The filter material of claim 1 or 2, further comprising one or more additional components selected from: alkyl ketene dimers, alkenyl succinic anhydride, fatty acids, starch, starch derivatives, carboxymethyl cellulose, alginate, or combustion additives selected from citrate, malate, tartrate, acetate, nitrate, succinate, fumarate, gluconate, glycolate, lactate, oxalate, salicylate, α-hydroxyoctanoate, phosphate, chloride and bicarbonate, and mixtures thereof.

11. The filter material as described in claim 1 or 2, further comprising a wet strength agent.

12. The filter material as described in claim 1 or 2, further comprising a substance for adjusting pH.

13. The filter material of claim 12, wherein the substance used to adjust the pH is an organic or inorganic acid or base.

14. The filter material as claimed in claim 1 or 2, further comprising one or more substances selected from: triacetin, propylene glycol, sorbitol, glycerin, polyethylene glycol, polypropylene glycol, polyvinyl alcohol, and triethyl citrate.

15. The filter material as claimed in claim 1 or 2, wherein the thickness, as measured according to ISO 534:2011, is at least 70 µm and at most 1000 µm.

16. The filter material as claimed in claim 1 or 2, wherein the tensile strength relative to the width, measured according to ISO 1924-2:2008, is at least 0.05 kN / m and at most 5 kN / m in at least one direction.

17. The filter material as claimed in claim 1 or 2, wherein the elongation at break, as measured according to ISO 1924-2:2008, is at least 3% and at most 40% in at least one direction.

18. A portion of a nicotine delivery product, wherein the nicotine delivery product is a smoking article, the portion comprising the filter material of claim 1 and a wrapping material wrapping the filter material.

19. The portion of claim 18, wherein the portion is a cylindrical shape having a circular base area, wherein the circular base area has a diameter of at least 5 mm and at most 8 mm.

20. The portion as claimed in any one of claims 18 or 19, having a length of at least 4 mm and at most 40 mm.

21. The portion as claimed in claim 18 or 19, wherein the suction resistance per length of the portion, as measured according to ISO 6565:2015, is at least 1 mm WG / mm and at most 12 mm WG / mm.

22. The portion of claim 18 or 19, wherein the wrapping material is paper.

23. The portion of claim 18 or 19, wherein the wrapping material is a film.

24. The portion of claim 18 or 19, wherein the packaging material has a reference weight of at least 20 g / m² and at most 150 g / m².

25. A smoking article comprising a portion containing a material that forms an aerosol, and the portion as described in claim 18.

26. The smoking article of claim 25, wherein the portion of claim 18 is the portion located beside the mouth end of the smoking article.

27. The smoking article of claim 25, wherein the smoking article is a filter cigarette, and the material forming the aerosol is tobacco leaf.

28. The smoking article of claim 25, wherein during its intended use, the aerosol-forming material is only heated but not burned, and the aerosol-forming material comprises tobacco, nicotine, glycerin, propylene glycol, or a mixture of two or more of these components.

29. The smoking article of claim 28, wherein the aerosol-forming material comprises reconstituted tobacco.

30. The smoking article of claim 25, wherein the wrapping material of the portion of claim 18 is at least partially transparent or has pores, and the filter material has at least 50% transparency as measured according to DIN 53147:1993-01.

31. An oral nicotine delivery product comprising a pouch formed of the filter material of claim 1 and containing a nicotine-containing material, wherein the filter material has a transparency of at least 50% and at most 70% as measured according to DIN 53147:1993-01.

32. A method for manufacturing filter material, comprising steps A to D: A – Provides a fiber web including cellulose fibers. B – To produce a hydrospun fiber web, the fiber web is hydroentangled by directing at least one jet of water onto the fiber web. C – A structure is created in the hydroentangled fiber web. D – Dry the hydroentangled fiber web. The amount of cellulose fiber selected in step A is such that, after drying in step D, the filter material contains at least 50% and at most 100% cellulose fiber relative to its mass. After drying in step D, the filter material has a reference weight of at least 25 g / m² and at most 60 g / m², and After drying in step D, the filter material is characterized by providing a transparency of at least 45% and at most 70% as measured according to DIN 53147:1993-01, and The structure in step C is generated by directing at least one water jet onto the fiber web while supporting the fiber web with a surface having multiple protrusions.

33. The method of claim 32, wherein step A comprises spinning a plurality of cellulose fibers, wherein the cellulose fibers are formed from filaments of regenerated cellulose, and wherein, after drying in step D, at least 90% by mass of the filter material is formed from filaments of regenerated cellulose.

34. The method of claim 32, wherein step A comprises steps A1 to A4: A1 – Manufacturing aqueous suspensions containing cellulose fibers, A2 – Apply the suspension from step A1 to the operating line. A3 – The suspension is dehydrated via the operating line to form a fiber web. A4 – Transfer the fiber web from step A3 to the support line.

35. The method of claim 34, wherein the aqueous suspension in step A1 has a solids content of up to 0.2%.

36. The method of claim 34, wherein the running lines of steps A2 and A3 are inclined horizontally upward at an angle of at least 3° and at most 40° relative to the running direction.

37. The method of claim 34, further comprising the step of generating a pressure difference between the two sides of the running line to support the dehydration of the suspension in step A3.

38. The method of claim 32, wherein multiple water jets are used to perform the hydroentangling in step B, wherein the water jets are arranged laterally in at least one row relative to the direction of travel of the fiber web.

39. The method of claim 32, wherein the hydroentangling in step B is performed by at least two water jets directed onto the fiber web, wherein the at least two water jets act from different sides of the fiber web.

40. The method of claim 32, wherein the fiber web in step C is supported by a cylinder having a plurality of protrusions positioned on its surface.

41. The method of claim 32, wherein the area of ​​each protrusion projected onto the surface of the fiber web supporting step C is at least 0.1 mm² and at most 15 mm².

42. The method of claim 32, wherein the drying in step D is performed at least in part by contact with hot air, by infrared radiation, or by microwave radiation.

43. The method of claim 32, wherein after drying in step D, the filter material is the filter material of claim 1.

Images