KR20240022530A - Filter material for smoking articles with improved stretching behavior - Google Patents

Abstract

The invention relates to a filter material for manufacturing segments for smoking articles, the filter material being in the form of a web, each containing at least 50% and at most 100% cellulosic fibers, based on the mass of the filter material, the filter material having at least It has a weight per unit area of 15 g/m2 and a maximum of 60 g/m2, the thickness of the layer of filter material measured according to ISO 534:2011 is a minimum of 25 ㎛ and a maximum of 1000 ㎛, the filter material is oriented in the machine direction and in the plane of the web of the filter material. and a transverse direction orthogonal to the machine direction, wherein the filter material, in a transverse tensile test according to ISO 1924-2:2008, has a transverse tensile test according to ISO 1924-2:2008 in which the non-linear portion of the strain energy absorbed by the filter material is equal to the elongation at break. It has a characteristic plastic deformability in the transverse direction, characterized by at least 10% and at most 50% of the total strain energy absorbed by the filter material by half.

Description

Filter material for smoking articles with improved stretching behavior

The present invention relates to a filter material suitable for producing segments in a smoking article, said filter material having a favorable plastic stretching behavior in the transverse direction and thereby forming a segment for the smoking article in an efficient manner. Segments can be manufactured. The invention also relates to segments for smoking articles made from the above filter material.

Smoking articles are generally rod-shaped articles consisting of at least two rod-shaped segments arranged one after another. One segment contains material capable of forming an aerosol when heated, and at least one additional segment is used to influence the properties of the aerosol.

The smoking article may be a filter cigarette in which a first segment contains aerosol-forming material, in particular tobacco, and a further segment is formed as a filter and serves to filter the aerosol. In this case, the aerosol is generated through combustion of the aerosol-forming material, and the filter serves to filter the aerosol and impart a defined draw resistance to the filter cigarette.

Additionally, the smoking article may be a so-called heated tobacco product in which the aerosol-forming material is only heated but not combusted. As a result, the number and amount of health hazardous substances in aerosols are reduced. Smoking articles of this type likewise consist of at least two segments, more often more than two, especially four segments. One segment contains aerosol-forming material, typically including tobacco, reconstituted tobacco, or otherwise processed tobacco. Other partially optional segments within the smoking article serve to deliver the aerosol, cool the aerosol, or filter the aerosol.

The segments are usually surrounded by wrapper material. Sometimes paper is used as wrapper material.

In the following, unless explicitly stated or the context directly indicates otherwise, the term "segment" refers to a segment of smoking material that does not contain aerosol-forming material but serves, for example, to transmit, cool or filter the aerosol. it means.

It is known from the prior art to form segments of this type from polymers such as cellulose acetate or polylactide. After consumption of the smoking article, the smoking article must be properly disposed of. However, in many cases consumers simply discard used smoking materials into the environment, and attempts to limit this behavior through notices or fines have not been very successful.

Because cellulose acetate and polylactide biodegrade very slowly in the environment, the importance of paper and cellulose-based nonwoven fabrics has increased.

For example, in the manufacture of segments, a web composed of paper or cellulose-based non-woven fabric may first be crimped longitudinally before forming it into a continuous tow and surrounding it with a wrapper material. You can. Finally, the continuous tow can be cut into suitable pieces for further processing.

When crimping a web, the web may pass through two patterned rollers, which imprint the pattern into the web. For example, the pattern may be a line pattern oriented in the machine direction of the web. Stamped lines of this type can be formed more simply by stretching and deforming the web in a direction perpendicular to the machine direction, i.e. transversely, and then continuous tows can be formed by gathering the web transversely. .

However, crimping of the type described can cause transverse rupture of the web. There is therefore a need for a filter material that has none or a lesser degree of these disadvantages, but is otherwise as identical as possible to the preferred filter material.

In unpublished international patent application PCT/EP2019/085125 by the same inventor, a hydroentangled filter material is described, which can serve as a starting point for a filter material according to the invention.

The object of the present invention is to provide a web-shaped filter material for smoking articles that can be processed into segments of smoking articles with high productivity and that is as similar as possible to the desired filter materials with respect to its properties.

The task is achieved through a filter material according to claim 1, a segment for a smoking article according to claim 17 and a smoking article according to claim 24, and a method for manufacturing the segment according to claim 23 and claim 28, This is solved through the method for manufacturing the filter material herein according to claims 31 and 32. Preferred improvements are specified in the dependent claims.

The inventors have discovered that the above problem can be solved by means of a filter material for the production of segments for smoking articles, the filter material being in the form of a web and having a content of at least 50% and at most 100%, respectively, based on the mass of the filter material. Containing cellulose fibers, the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2.

The thickness of the layer of filter material measured according to ISO 534:2011 is a minimum of 25 μm and a maximum of 1000 μm. Thickness determines the amount of filter material that can be packed within a segment of a smoking article and thus the suction resistance and filtration efficiency of the segment, as well as the filter material especially when crimped or pleated for the manufacture of the segment for a smoking article. affects the processability of For these process steps, too large a thickness is not suitable, but the thickness of the mentioned intervals allows the filter material according to the invention to be processed very well into segments of smoking articles.

Additionally, the filter material has a machine direction and a transverse direction orthogonal to this machine direction in the plane of the web of filter material. Additionally, the filter material is determined in a transverse tensile test according to ISO 1924-2:2008, where the non-linear portion of the strain energy absorbed by the filter material up to half its elongation at break is the total strain energy absorbed by the filter material up to half its elongation at break. It has a characteristic plastic deformability in the transverse direction, characterized by a minimum of 10% and a maximum of 50% of. This unique plastic deformability is more pronounced than in conventional filter materials.

During the production and further processing of the filter material, the filter material runs in one direction, i.e. in the so-called machine direction, passing through the machine, and the filter material runs in a direction perpendicular to the machine direction in the web plane of this filter material, i.e. transverse. have

When processing the filter material into segments of smoking articles, the filter material is preferably crimped. For this purpose, the filter material passes through two rollers, for example with a pattern, which imprints the pattern into the web. Preferably the pattern is a line pattern oriented in the machine direction of the web. The engraved lines stretch and deform the filter material in a direction perpendicular to the machine direction, i.e. transversely. Filter material modified in this way can be more simply gathered transversely, thereby producing continuous tows for the production of segments.

However, the problem with this method is that in order to achieve the desired deformation of the filter material, a high transverse elongation must be applied to the web via the two rollers, which runs the risk of transverse rupture of the filter material. The person skilled in the art can now attempt to increase the transverse elongation at break of the filter material so that the filter material can withstand greater deformation without rupturing. However, the inventors recognized that the problem could not be solved that way, because to achieve sustained deformation in the transverse direction the elongation would have to be higher and higher, thereby increasing even more the risk of exceeding the failure load in the transverse direction.

More importantly, according to the results of the inventors' research, continuous plastic deformation occurs at the transverse elongation at which the filter material is exposed during crimping, but no elastic deformation occurs. If this plastic deformation can already be achieved with a greater separation of the rollers during crimping, the risk of the filter material breaking transversely during processing is reduced. In this case, it should generally be sufficient to transversely stretch the filter material to approximately half its elongation at break.

On the other hand, the inventors have discovered that, through suitable methods, the filter material can be provided with a structure that allows excellent plastic deformability in the transverse direction and thus simplifies crimping. Methods suitable for this are explained further below. This transverse plastic deformability can be characterized through tensile testing according to ISO 1924-2:2008. In this tensile test, a strip 15 mm wide is taken transversely from the sample and stretched at a rate of 20 mm/min until fracture. Here the elongation (ε) and the applied force (F) are detected, thereby deriving the force-elongation curve [F(ε)]. Likewise, elongation at break (ε _b ) and tensile strength [F(ε _b )] are also detected. Then the following formula:

Based on this, the strain energy (E) absorbed by the filter material up to half the elongation at break (ε _b /2) is obtained, and in practice the integral is calculated numerically.

This strain energy consists of an elastic part and a plastic part. The elastic deformation returns after load relief and therefore has no effect on the crimping result. On the contrary, plastic deformation is irreversible, so that already at small elongations through two rollers, excellent results can be expected when crimping if the part of the plastic deformation energy in the total deformation energy is higher than in the case of comparable filter materials of the prior art. there is.

Elastic deformation is generally associated with a proportional relationship between elongation and force. The strain energy (E _lin ) up to half the elongation at break can be calculated by the formula:

In this case, the nonlinear part (E _nl ) of the strain energy introduced into the filter material up to half the elongation at break that exceeds this strain energy is:

According to the inventors' findings, the nonlinear part of the strain energy absorbed transversely up to half the elongation at break is at least 10% of the total strain energy absorbed transversely up to half the elongation at break, that is, the inequality When applied, very good results are achieved when crimping.

These considerations for quantifying plastic behavior can be illustrated, for example, through the diagram shown in Figure 1, as may arise when performing tensile tests according to ISO 1924-2:2008. The elongation rate (ε) is indicated on the x-axis 10, and the force [F(ε)] required to produce this elongation is indicated on the y-axis 11. Starting from the unloaded state (12), the elongation (ε) increases at a rate of 20 mm/min, and at the same time the force [F(ε)] is measured and a force-elongation curve (13) is generated. In this case, the elongation increases until the sample ruptures in state 14, and based on this, the elongation at break (ε _b ) and tensile strength [F(ε _b )] are determined.

When manufacturing segments from filter material, the filter material is loaded with a corresponding force [F(ε _b /2)] depending on the position, for example up to approximately half the elongation at break (ε _b /2), i.e. up to point 15. can be received, thereby reaching state (16).

The line 17 connecting points 12 and 16 may represent a hypothetical linear elastic behavior, with the linear strain energy E _lin corresponding to the area of the triangle formed by points 12, 16 and 15. On the other hand, the total strain energy (E) is the line from point 12 to point 15, the line from point 15 to point 16, and the line from point 16 to point 12 (13). ) corresponds to the area enclosed by . The nonlinear part of the strain energy (E _nl ) used for the characterization of the filter material according to the invention within the scope of the invention is applied to the area defined by the lines 17 and 13 between the points 12 and 16 respectively. corresponds to That is, the more strongly the force-elongation curve bends upward and the more it deviates from hypothetical linear elastic behavior, the greater the likelihood of plastic deformation and subsequent irreversible deformation.

When manufacturing segments from the filter material according to the invention, the elongation in the transverse direction at the time of crimping may naturally deviate from half the elongation at break, but the non-linear part of the strain energy up to half the elongation at break is the difference actually applied. Independently of the elongation and the actual elastic-plastic behavior, it has been found to be a suitable parameter to characterize the structure of the filter material according to the invention and to predict its behavior when crimping.

For comparison, Figure 2 shows the behavior of a typical conventional filter material not according to the invention. Here too, tensile tests according to ISO 1924-2:2008 are performed on the samples in the transverse direction. The elongation rate (ε) is indicated on the x-axis 20, and the force [F(ε)] required to generate this elongation is indicated on the y-axis 21. Starting from the unloaded state (22), the elongation (ε) increases at a rate of 20 mm/min and at the same time the force [F(ε)] is measured, and a force-elongation curve (23) is generated. In this case, the elongation increases until the sample ruptures in state 24, and based on this, the elongation at break (ε _b ) and the tensile strength [F(ε _b )] are determined.

When manufacturing segments from filter material, the filter material can be loaded with the corresponding force [F(ε _b /2)], for example up to approximately half the elongation at break (ε _b /2), i.e. up to point 25. There is, and thus state (26) is reached.

The line 27 connecting points 22 and 26 may exhibit linear elastic behavior, with the associated strain energy E _lin corresponding to the area of the triangle formed by points 22, 26 and 25. On the other hand, the total strain energy (E) is the line from point 22 to point 25, the line from point 25 to point 26, and the line from point 26 to point 22 (23). ) corresponds to the area enclosed by . The nonlinear part E _nl of the strain energy corresponds to the area defined by the lines 27 and 23 between the points 22 and 26 respectively. If the elongation at break is very similar and the linear part of the strain energy is also very similar, we can see that the nonlinear part of the strain energy is much smaller. These filter materials therefore respond particularly elastically to deformation and recover substantially their entire deformation after load relief. In order to introduce a similar plastic strain energy indicated by line 28 as in the case of the filter material shown in Figure 1, the filter material would have to be stretched to point 29. The elongation required for this is much higher and, in particular, the force required approaches the breaking load in the transverse direction. Therefore, if there is a small breakdown in the machine or a change in the quality of the filter material, the filter material may burst transversely. On the contrary, the filter material according to the invention of Figure 1 has a structure that allows continuous deformation in the transverse direction even at already low elongations, so that segments for smoking articles can be produced more reliably on the basis of this filter material. .

The filter material according to the invention is in web form to make it highly suitable for crimping.

In one preferred embodiment of the filter material, the filter material is a hydroentangled nonwoven fabric or paper.

In one preferred embodiment of the filter material, the filter material is a hydraulically entangled nonwoven fabric.

In one preferred embodiment of the filter material, the filter material is paper.

Although the term "hydroentangled" refers primarily to the basic manufacturing method, hydraulically entangled nonwovens have structural properties that distinguish them from other nonwovens and, to the knowledge of the inventor, cannot be achieved in the same way through other manufacturing methods. must be taken into consideration. For example, unlike the case of paper, where strength is achieved primarily through hydrogen bridges and the fibers are arranged specifically in the plane of the paper, in the case of hydraulically entangled nonwovens, strength is achieved through entanglement of the fibers. . Hydraulically entangled nonwovens have a particularly porous structure that makes them well suited as filter materials for segments for smoking articles.

If the filter material is paper, a similar porous structure is preferably created using an inclined wire paper machine. Therefore, the properties of the filter material according to the invention, the segments according to the invention made from this filter material and the smoking articles according to the invention made from these segments, described below, indicate that the filter material according to the invention is capable of hydraulic entanglement. Applies regardless of whether it is non-woven or paper.

The third process according to the invention for the production of the filter material according to the invention, which is explained in particular further below, involves a combination of papermaking and hydraulic entanglement, so that the filter material thus obtained is explicitly referred to as paper or hydraulically entangled non-woven fabric. It can't be.

The filter material according to the invention contains cellulose fibers. According to the inventors' findings, cellulose fibers are needed to provide sufficient strength to the filter material so that it can be processed into segments. The proportion of cellulosic fibers in the filter material is according to the invention at least 50% and at most 100% of the mass of the filter material, based on the mass of the filter material respectively, preferably at least 60% and at most 100%, very preferably The minimum is 70% and the maximum is 95%.

Cellulosic fibers may be pulp fibers, or fibers of regenerated cellulose, or mixtures thereof.

The pulp fibers are preferably from coniferous forests, deciduous forests, or from other plants such as hemp, flax, jute, hemp, kenaf, Kapok, coconut, abaca, sisal, bamboo, cotton, or Obtained from esparto grass. Blends consisting of pulp fibers from various sources can also be used for the production of hydraulically entangled filter materials. It is particularly preferred that pulp fibers are obtained from coniferous forests, since these fibers impart excellent strength to the filter material even in smaller proportions.

The filter material according to the invention may contain fibers of regenerated cellulose material. Preferably the proportion of fibers of regenerated cellulose material is at least 5% and at most 50%, very preferably at least 10% and at most 45%, very particularly preferably at least 15% and at most 50%, respectively, based on the mass of the filter material. The maximum is 40%.

The fibers of the regenerated cellulose material are preferably formed at least partially, especially at least 70%, of viscos fibers, modal fibers, Lyocell® fibers, Tencel® fibers or mixtures thereof. These fibers have excellent biodegradability and can be used to optimize the strength of filter materials and adjust the filtration efficiency of segments for smoking articles made from such filter materials. These fibers, due to their manufacturing method, are less variable than pulp fibers obtained from natural sources, allowing the properties of segments made from filter materials to vary less than when pulp fibers alone are used. However, the production of these fibers is more complex and typically more expensive than pulp fibers.

The weight per unit area of the filter material is according to the invention at least 15 g/m2 and at most 60 g/m2, preferably at least 18 g/m2 and at most 55 g/m2, very preferably at least 20 g/m2 and at most 50 g/m2. . Weight per unit area affects the tensile strength of the filter material, with higher weight per unit area generally leading to higher strength. However, the weight per unit area should not be too high, since in that case the filter material can no longer be processed into segments for smoking articles at high speeds. This information relates to weight per unit area measured according to ISO 536:2019.

For the filter material according to the invention, in the transverse tensile test according to ISO 1924-2:2008, the nonlinear part of the strain energy, which is absorbed by the filter material up to half its elongation at break, is absorbed by the filter material up to half its elongation at break. A minimum of 10% and a maximum of 50% of the total strain energy absorbed. Preferably, the non-linear part of the strain energy absorbed by the filter material up to half its elongation at break is at least 15% and at most 40% of the total strain energy absorbed by the filter material up to half its elongation at break, particularly preferably The nonlinear part is at least 15% and at most 35%, especially at least 18% and at most 32%. With moderate elongations at preferred and highly preferred distances, very good results are achieved when crimping and the risk of transverse rupture of the filter material is very low.

The filter material according to the invention can be mixed with alkyl ketene dimer (AKD), acid anhydride such as alkenyl succinic anhydride (ASA), polyvinyl alcohol, wax, fatty acid, starch, starch, etc. to adjust the specific characteristics. It may contain additives such as derivatives, carboxymethyl cellulose, alginates, chitosan, wet strength agents, or substances for setting the pH value, such as organic or inorganic acids or bases. Alternatively or additionally, the filter material according to the invention may be selected from citrate such as trisodium citrate or tripotassium citrate, malate, tartrate, acetate such as sodium or potassium acetate, nitrate, succinate, fumarate. , gluconates, glycolates, lactates, oxalates, salicylates, α-hydroxycaprylate, phosphates, polyphosphates, chlorides and sodium bicarbonate, and mixtures thereof. You can. A person skilled in the art can determine the type and amount of the additive based on his/her own experience.

Additionally, the filter material according to the invention may also comprise other materials that better match the filtration efficiency of the filter material to that of cellulose acetate. In one preferred embodiment of the filter material according to the invention, the filter material is or a material selected from the group consisting of triacetin, propylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol and triethyl citrate. Contains a mixture of

In one preferred embodiment of the filter material, at least some of the cellulose fibers are filled with filler, which is particularly preferably formed from mineral particles and in particular calcium carbonate particles. Since the structure of the filter material is very porous and therefore unsuitable for holding filler material, it is advantageous to fill the cellulose fibers with filler material to secure the cellulose fibers within the structure of the filter material. Fillers can serve to impart special properties to the filter material.

The thickness of the layer of filter material, measured according to ISO 534:2011, is at least 25 μm and at most 1000 μm, preferably at least 30 μm and at most 800 μm, very preferably at least 35 μm and at most 600 μm.

The mechanical properties of the filter material are important for processing the filter material according to the invention into segments of smoking articles. The width-related tensile strength of the filter material in the transverse direction, measured according to ISO 1924-2:2008, is preferably at least 0.05 kN/m and at most 5 kN/m, very preferably at least 0.07 kN/m and at most 4 kN/m. m.

The elongation at break of the filter material in the transverse direction, measured according to ISO 1924-2:2008, is therefore preferably at least 0.5% and at most 50%, very preferably at least 0.8% and at most 40%. The elongation at break is determined in particular by the length of the fiber: the longer the fiber, the higher the elongation at break, and thus the elongation at break can be adjusted within a wide range to the specific requirements of the filter material.

Segments for smoking articles according to the invention can be produced from the filter material according to the invention by methods known in the prior art. The method includes, for example, crimping the filter material, forming a continuous tow from the crimped filter material, wrapping the continuous tow with a wrapper material, and cutting the wrapped tow into individual bars of a defined length. Includes. In many cases, the length of such a rod is an integer multiple of the length of the segment that is to be subsequently used in a smoking article according to the invention, so that the rod is cut into segments of the desired length before or during production of the smoking article.

The segment for a smoking article according to the invention comprises a filter material and a wrapper material according to the invention.

Specifically, the segments include transversely gathered filter material and wrapper material, each of which contains at least 50% and at most 100% cellulosic fibers based on the mass of the filter material. In this case, the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 is at least 25 μm and at most 1000 μm. For the determination of the weight per unit area, the area of the filter material when laid out (i.e. no longer gathered) is taken as reference, and the thickness of the layer is also naturally related to the spread out filter material. The filter material has a transverse direction in which the filter material is gathered. To facilitate gathering of the filter material, the filter material may be preformed through crimping or pleating. In this regard, the term “gathering” should be interpreted broadly and the verb “gather” included therein is not intended to suggest any particular mechanical way of creating a “gathered” state. A “pleated” state is also, for example, a “gathered” state in the context of the present disclosure, regardless of the mechanical manner in which it is pleated or shortened in the transverse direction. Additionally, the filter material in the ungathered state shows that in a transverse tensile test according to ISO 1924-2:2008, the nonlinear portion of the strain energy absorbed by the filter material up to half its elongation at break is absorbed by the filter material up to half its elongation at break. It has a characteristic plastic deformability in the transverse direction, characterized by a minimum of 10% and a maximum of 50% of the total strain energy absorbed.

In one preferred embodiment of the segment according to the invention, the segment has a diameter of at least 3 mm and at most 10 mm, very preferably at least 4 mm and at most 9 mm, very particularly preferably at least 5 mm and at most 8 mm. It is cylindrical. This diameter is advantageous for using the segments according to the invention in smoking articles.

In one preferred embodiment of the segment according to the invention, the segment has a length of at least 4 mm and at most 40 mm, very preferably at least 6 mm and at most 35 mm, very particularly preferably at least 10 mm and at most 28 mm. .

The resistance to draw of a segment determines how much pressure difference must be applied to produce a particular volumetric flow rate through the smoking article, especially when the consumer uses the smoking article, and therefore the resistance to draw effectively determines the consumer's Affects acceptance of smoking items. The suction resistance of a segment can be measured according to ISO 6565:2015 and is specified in mm water gauge (mmWG). To a very good approximation, the resistance to attraction of a segment is proportional to the length of the segment, so measurements of resistance to attraction can be made even for rods that are distinct from the segments only in length. Based on this, the suction resistance of the segment can be calculated simply.

The suction resistance of the segment per segment length is preferably at least 1 mm WG/mm and at most 12 mm WG/mm, very preferably at least 2 mm WG/mm and at most 10 mm WG/mm.

The wrapper material for the segments according to the invention is preferably paper or film.

The wrapper material of the segments according to the invention preferably has a weight per unit area according to ISO 536:2019 of at least 20 g/m 2 and at most 150 g/m 2, very preferably at least 30 g/m 2 and at most 130 g/m 2. A wrapper material having this preferred or very preferred weight per unit area imparts a very desirable hardness to the segments according to the invention wrapped therewith.

Smoking articles according to the invention can be produced from the segments according to the invention according to methods known in the prior art.

A smoking article according to the invention comprises a segment containing an aerosol-forming material and a segment comprising a filter material and a wrapper material according to the invention.

Since the cut surface of the segment according to the invention is visually very similar to that of the segment made of cellulose acetate, in one preferred embodiment the segment of the smoking article located closest to the mouth end is the segment according to the invention.

In one preferred embodiment, the smoking article is a filter cigarette and the aerosol-forming material includes tobacco.

In one preferred embodiment, the smoking article is a smoking article in which, when used in accordance with the instructions, the aerosol-forming material is heated but not combusted, the aerosol-forming material preferably consisting of tobacco, regenerated tobacco, nicotine, glycerol, propylene glycol. It includes materials selected from the group or mixtures thereof. In this case, the aerosol-forming material may be in liquid form and placed in a suitable container within the smoking article.

According to the findings of the present inventors, the non-linear part of the strain energy according to the invention can be achieved by a stronger alignment of the fibers in the filter material in the machine direction of the filter material. This is achieved through methods according to the invention described below.

The filter material according to the invention can be produced according to the first method according to the invention comprising the following steps A1 to A3.

A1 - supplying a fibrous web comprising cellulosic fibers and having a machine direction and a transverse direction orthogonal to this machine direction in the web plane;

A2 - a step of hydraulic entanglement of the fiber web by means of a water jet directed towards the fiber web, to produce a hydraulically entangled fiber web;

A3 - Drying the hydraulically entangled fiber web.

In step A1, the amount or proportion of cellulosic fibers in the fibrous web is selected such that after drying in step A3 the filter material contains at least 50% and at most 100% cellulosic fibers based on the mass of the filter material,

In step A2, the number, pressure or arrangement of the water jets is such that up to half of the elongation at break is absorbed by the filter material in a transverse tensile test according to ISO 1924-2:2008, performed on the filter material after drying in step A3. It is selected to give the filter material a characteristic plastic deformability in the transverse direction, characterized in that the non-linear part of the strain energy is at least 10% and at most 50% of the total strain energy absorbed by the filter material up to half the elongation at break; ,

After drying in step A3 the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 after drying in step A3 is at least 25 μm and The maximum is 1000㎛.

In step A2, water jets directed towards the fibrous web cause entanglement of the cellulosic fibers and a structure can be created that leads to a favorable plastic behavior in the transverse direction. In this case, “pressure of the water jet” means, for a person skilled in the art, the pressure applied, for example in a pressure chamber, for the creation of a water jet. According to the research results of the present inventors, in order to achieve desirable plastic behavior of the filter material, the proportion of transversely oriented fibers in the filter material must be low. It is important for the fibers to be more aligned in the machine direction and thickness direction. To create this structure according to the invention in the filter material, the water jets must be arranged close to each other in the transverse direction. Due to the proximity of the water jets simultaneously hitting the fiber web, the water is distributed in the machine direction rather than transversely, causing the fibers to orient in this direction.

In this case, the pressure of the water jet may be reduced compared to the pressure normally used. However, since the spacing and pressure of the water jets are significantly dependent on the size of the opening through which the water jets are discharged, and especially on the speed of the fiber web, a person skilled in the art will be able to determine the difference based on experience, according to specific embodiments, and through simple experiments. You can select a specific value.

In one preferred embodiment of the first method according to the invention, a plurality of water jets are used to carry out the hydraulic entanglement in step A2, these water jets being arranged in at least one row transverse to the machine direction of the fibrous web. are arranged.

In a preferred embodiment of the method according to the invention, the hydraulic entanglement in step A2 is carried out via at least two rows of water jets directed towards the fibrous web, very preferably at least one row on each of the two sides of the fibrous web. The water jet works.

Filter material produced according to this first method should be suitable for use in segments for smoking articles. This means that the filter material may have, individually or in combined form, all the features that are particularly described above in relation to the filter material and defined in the claims directed to the filter material.

The filter material according to the invention can be produced according to the second method according to the invention comprising the following steps (B1 to B4).

B1 - Preparing an aqueous suspension comprising cellulose fibers;

B2 - applying the suspension of step B1 to the circulating wire;

B3 - dewatering the suspension through a circular wire to form a fibrous web;

B4 - drying the fiber web of step B3.

In step B1, the amount or proportion of cellulose fibers is selected so that after drying in step B4 the filter material contains at least 50% and at most 100% cellulose fibers based on the mass of this filter material,

In step B3, the machine direction of the fiber web is defined by the running direction of the wire, and the transverse direction is defined by a direction orthogonal to the machine direction in the plane of the fiber web,

In step B2, the suspension is applied onto the circulating wire at a speed lower than that of this circulating wire, and the difference between these rates is carried out on the filter material after drying in step B4, according to ISO 1924-2:2008. Transverse, characterized in that the non-linear part of the strain energy absorbed by the filter material up to half the elongation at break in the transverse tensile test is at least 10% and at most 50% of the total strain energy absorbed by the filter material up to half the elongation at break. selected to impart characteristic plastic deformability in the direction to the filter material,

After drying in step B4, the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 after drying in step B4 is at least 25 μm and The maximum is 1000㎛.

In this case, the velocities of the circulating wire and the suspension should each be understood with respect to the same frame of reference, such that the different velocities result in the relative velocities between the suspension and the circulating wire being used in this embodiment of the method. .

Filter material produced according to this second method should be suitable for use in segments for smoking articles. This means that the filter material may have, individually or in combined form, all the features that are particularly described above in relation to the filter material and defined in the claims directed to the filter material.

In this second method according to the present invention, the fibrous web obtains the desired structure by adjusting the speed at which the suspension flows onto the circulating wire in step B2 and the speed of the circulating wire in step B2 to be mutually appropriate. In particular, according to the results of the inventor's research, the speed at which the suspension flows onto the circulating wire in step B2 should be lower than the speed of the circulating wire. The velocity difference carries the suspension together with the wire and creates shear forces in the suspension that contribute to the structure of the filter material, which aligns the cellulose fibers in the machine direction and achieves plastic deformability according to the invention in the transverse direction. A person skilled in the art can determine the size of the speed difference according to his or her experience, based on examples, or through simple experiments. According to the experience of the present inventors, structures with the desired plastic deformability in the transverse direction are, in many cases, formed so that in step B2 the suspension is deposited on the circular wire at only about 90% of the circular wire speed, for example between 88% and 88% of the circular wire speed. This can be achieved when applied at a rate of between 93%. Since these values only serve as a reference point and the suitable numerical value of the speed difference is determined at least in part by the remaining process parameters, the person skilled in the art will calculate the numerical value in practice from experiments, in this case, as above. The characteristic plastic deformability of the filter material produced as above in the transverse direction, characterized with reference to the transverse tensile test according to ISO 1924-2:2008 as described above, serves as a guideline and ultimately a decisive criterion. .

Additionally, the filter material according to the invention can also be produced in a third method according to the invention, which is a combination of the first and second methods according to the invention but also comprises steps C1 to C6 below.

C1 - preparing an aqueous suspension comprising cellulose fibers;

C2 - applying the suspension from step C1 onto the circulating wire;

C3 - dewatering the suspension through a circular wire to form a fibrous web;

C4 - the fibrous web in step C3 is transferred onto the support wire;

C5 - hydraulic entanglement of the fiber web by means of a water jet directed towards the fiber web, to produce a hydraulically entangled fiber web; and

C6 - drying the hydraulically entangled fiber web;

In step C1, the amount or proportion of cellulose fibers is selected such that after drying in step C6 the filter material contains at least 50% and at most 100% cellulose fibers based on the mass of this filter material,

In step C3, the machine direction of the fiber web is defined by the running direction of the wire, and the transverse direction is defined by a direction orthogonal to the machine direction in the plane of the fiber web,

After drying in step C6 the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 after drying in step C6 is at least 25 μm and The maximum is 1000㎛,

In step C2 the suspension is applied onto the circulating wire at a speed lower than the speed of this circulating wire, the difference between said velocities in step C2 and the number, pressure and/or arrangement of water jets in step C5 being determined by: In a transverse tensile test according to ISO 1924-2:2008, performed on the filter material after drying at C6, the nonlinear part of the strain energy absorbed by the filter material up to half its elongation at break is determined by the filter material up to half its elongation at break. It is selected so as to impart to the filter material a characteristic plastic deformability in the transverse direction, characterized by at least 10% and at most 50% of the total strain energy absorbed.

In one preferred embodiment of the second or third process according to the invention, the aqueous suspension in step B1 or C1 is at most 3.0%, very preferably at most 1.0%, very particularly preferably at most 0.2%, especially at most 0.05%. It has a solid content of The very low solids content of the suspension allows the formation of a low-density fibrous web in step B3, which has an advantageous effect on the filtration efficiency of the segments made from this fibrous web.

In one preferred embodiment of the second or third method according to the invention, the circular wires of steps B2 and B3 or C2 and C3 are bent in the machine direction of the fibrous web by an angle of at least 3° and at most 40° relative to the horizontal. It is preferably inclined upward by an angle of at least 5° and at most 30°, very particularly preferably by an angle of at least 15° and at most 25°.

In one preferred embodiment of the second or third method according to the invention, the method comprises the step of creating a pressure difference between the two sides of the circulating wire to support the dewatering step of the suspension in step B3 or C3. The pressure difference is very preferably created by vacuum boxes or suitably formed foils.

In one preferred embodiment of the first, second or third method according to the invention, the drying step in step A3, B4 or C6 is carried out at least partially through contact with hot air, through infrared radiation or through electromagnetic radiation. It is carried out through Drying through direct contact with a heated surface is likewise possible, but is less desirable as this may reduce the thickness of the filter material.

The preferred embodiments of the first method according to the invention can also be applied to the third method according to the invention, where step A2 corresponds to step C5 and step A3 corresponds to step C6. Likewise, the preferred embodiments of the second method according to the invention can also be applied to the third method according to the invention, where step B1 corresponds to step C1, step B2 corresponds to step C2 and step B3 corresponds to step C3. Correspondingly, step B4 corresponds to step C6.

In one preferred embodiment of the first, second or third method according to the invention, the method comprises the further step in which one or more additives are applied onto the fibrous web. The additive is preferably an alkyl ketene dimer (AKD), an acid anhydride such as alkenyl succinic anhydride (ASA), polyvinyl alcohol, wax, fatty acid, starch, starch derivative, carboxymethyl cellulose, alginate, chitosan, humectant, or It is selected from the group consisting of pH value adjusting substances, such as organic or inorganic acids or bases, and mixtures thereof. Alternatively or in addition, citrates such as trisodium citrate or tripotassium citrate, malates, tartrate, acetates such as sodium or potassium acetate, nitrates, succinates, fumarates, gluconates, glycolates, lactic acid. One or more additives selected from the group consisting of tates, oxalates, salicylates, α-hydroxycaprylate, phosphates, polyphosphates, chlorides and sodium bicarbonate, and mixtures thereof may also be applied.

In one preferred embodiment, the application of an additive or additives is carried out between steps A2 and A3 or after step A3 of the method according to the invention, followed by a further step of drying the fibrous web.

In one preferred embodiment of the second method according to the invention, the application of one additive or additives is carried out between steps B3 and B4 or after step B4 of the method according to the invention, followed by drying the fibrous web. Additional steps are performed as directed.

In one preferred embodiment of the third process according to the invention, the application of one additive or additives is performed between steps C3 and C4, or between steps C4 and C5, or between steps C5 and C6, or Carried out after C6, followed by an additional step of drying the fiber web.

1 is an exemplary force-elongation diagram of a filter material according to the invention.
Figure 2 is an exemplary force-elongation diagram of a filter material not in accordance with the present invention.
Figure 3 shows an apparatus that can be used to carry out the third method according to the invention for producing the filter material according to the invention.
Figure 4 is a graph showing the force-elongation curves measured in the transverse direction in Examples A, B and C according to the present invention.
Figure 5 is a graph showing force-elongation curves measured in the transverse direction in Comparative Example Z, which is not according to the present invention.

In the following, some preferred embodiments of filter materials, methods for producing filter materials, segments for smoking articles and smoking articles are described. Additionally, comparative examples not according to the present invention are also described.

Examples A, B and C

For the preparation of Examples A, B and C according to the invention, the apparatus shown in Figure 3 was used.

The suspension 31 consisting of pulp fibers and fibers of regenerated cellulose material is fed into a storage tank 32 (step C1), where it is pumped onto a circulation wire 33 inclined upward with respect to the horizon (step C2) and vacuum. Dewatering was carried out through boxes 39 (step C3), thereby forming a fibrous web 34 on the wire, the general direction of movement of which is indicated by arrows 310. In this case, in order to orient the fibers especially in the machine direction, the speed at which the wire 33 moves was chosen to be approximately 10% higher than the speed of the suspension 31 leaving the storage tank 32. The fibrous web 34 was removed from the wire 33 and transferred onto the likewise circulating support wire 35 (step C4). There, in order to entangle the fibers and solidify the fiber web 34 into a nonwoven fabric, water jets 311 arranged in a plurality of rows transverse to the machine direction of the fiber web 34 are sent from the device 36 to the fiber web. It was oriented towards (34) (step C5). Continuing from step C5, the water jet 312 was also directed towards the other side of the fibrous web 34 via a further device 37 . Then, to obtain a filter material, the still wet nonwoven fabric is passed through a drying unit 38 and dried there (step C6).

For the production of the filter material, a mixture of pulp fibers originating from coniferous forests and Lyocell® fibers was used, and the fiber content was selected so that the finished filter material consists of 65% pulp fibers and 35% Lyocell® fibers. did. The finished filter material had a weight per unit area of 55 g/m2 according to ISO 536:2019.

In step C5 of the manufacturing process, first three rows of water jets 311 (FIG. 3) are directed towards the first side of the fiber web 34 and then one row of water jets 312 (FIG. 3) is directed towards the fiber web 34. It was oriented towards the second side of the web 34. At this time, the pressure of the water jet was varied between 2 MPa and 40 MPa in three steps (low pressure, medium pressure, high pressure) to obtain different filter materials (A, B and C) according to the invention. The diameters of the openings through which the water jet is discharged were selected differently in the above rows between 80 ㎛ and 120 ㎛, and the spacing between the center points of the openings was 0.3 mm.

Samples were taken transversely from the filter materials and force-elongation diagrams were recorded in tensile tests according to ISO 1924-2:2008. The results are shown in Figure 4. The elongation in % is written on the x-axis 40, and the force in N is written on the y-axis 41. The three lines designated A, B and C represent the force-elongation diagram of the three filter materials (A, B and C) according to the invention. For example, the determination of the nonlinear portion of the strain energy absorbed up to half the elongation at break out of the total strain energy absorbed up to half the elongation at break for a filter material (C) is described.

At half the elongation at break (ε _b /2), the corresponding force [F(ε _b /2)] is determined, and on this basis the linear part of the strain energy (E _lin ) can be calculated as follows.

The total strain energy (E) absorbed up to half the elongation at break corresponds to the area spanning the x-axis (40) and the curve (C) from ε = 0 to ε = ε _b /2, and can be obtained without problems through numerical integration methods. Can be determined with sufficient accuracy. Here, if the linear part of the strain energy (E _lin ) is subtracted, a hatched area corresponding to the nonlinear part of the strain energy (E _nl ) remains.

Determination of the strain energy up to half the elongation at break was performed for a total of three filter materials (A, B and C) and the results are specified in Table 1, where E in the transverse direction is up to half the elongation at break, respectively. The total strain energy, E _lin is the linear part of the strain energy, and E _nl is the non-linear part of the strain energy. The strain energy was determined numerically from the force-elongation curve and has formal units of N%. To reach the general unit of J/㎡, sample geometry must also be considered. However, since only the mutual ratio is important here and the sample shape is the same, the above work is omitted. The elongation at break (ε _b ) and the force at half the elongation at break [F(ε _b /2)] are also specified.

Example enter ε _b [%] F(ε _b /2) [N] E E _lin E _nl E _nl /E [%] A low pressure 43.0 4.28 59.3 46.0 13.3 22.4 B pressure 40.8 3.92 55.3 40.0 15.3 27.7 C high pressure 32.4 3.24 34.1 26.2 7.9 23.0

The values in Table 1 show that in Examples A, B and C according to the invention, there is a non-linear part of the strain energy of about 20% to about 30%. Additionally, it can be seen that the elongation at break decreases when the pressure of the water jet increases. For this reason, it may be advantageous to choose a low pressure of the water jet, since in this case, in addition to good plastic stretching behavior, much larger permanent deformations are possible during crimping.

Example D

For the preparation of Example D according to the invention, the second process according to the invention was chosen comprising steps B1 to B4.

For the manufacture of the filter material, a mixture consisting of pulp fibers originating from coniferous forests and Lyocell® fibers was used, the fiber content being selected so that the finished filter material consists of 80% pulp fibers and 20% Lyocell® fibers. did. The finished filter material had a weight per unit area of 15 g/m2 according to ISO 536:2019.

In step B2 of the process according to the invention, the velocity of the discharged suspension is selected to be about 10% lower than the velocity of the circulating wire.

Four samples were taken transversely from the filter material (D) thus obtained, and the force-elongation diagram was recorded in a tensile test according to ISO 1924-2:2008. Evaluation of the force-elongation diagram was performed similarly to Examples A to C. The results of the four measurements are shown in Table 2.

Example ε _b [%] F(ε _b /2) [N] E E _lin E _nㅣ E _nl /E [%] D 4.20 5.97 9.19 6.27 2.92 31.8 D 3.13 5.43 5.91 4.25 1.66 28.1 D 3.56 5.79 7.39 5.15 2.24 30.3 D 4.08 5.90 8.55 6.02 2.53 29.6

The values in Table 2 show that in the filter material (D) according to the invention there is a non-linear part of the strain energy of about 30% and that repeated measurements for the same sample material have low dispersion. This demonstrates that method steps B1 to B3 actually contribute to the desired plastic deformability in the transverse direction when in step B2 the suspension is applied at a reduced rate on the circular wire.

Example E

On the other hand, in order to ensure the characteristic plastic deformability according to the invention in the transverse direction in the hydraulically entangled nonwoven, the special performance of step C2 used in Examples A to C (application of a reduced application rate of the suspension) is not necessary. This can be seen in Example E described below. For the preparation of example E according to the invention, the first process according to the invention was chosen comprising steps A1 to A3.

For the production of a hydraulically entangled filter material, Example E used a mixture of pulp fibers derived from coniferous forests and Lyocell® fibers, and the fiber content was such that the finished filter material was 80% pulp fibers and 20% fibers. It was chosen to be composed of Lyocell® fiber. Step A1 was first carried out at a reduced application rate of the suspension as in step B2 or C2 of the second or third method without imparting a preferred direction to the pulp fibers in the fiber web transverse to the machine direction. . The finished filter material had a weight per unit area of 15 g/m2 according to ISO 536:2019.

Hydraulic entanglement step A2 is performed like step C5 of Example B.

Two samples were taken transversely from the filter material (E) thus obtained and the force-elongation diagram was recorded in a tensile test according to ISO 1924-2:2008. Evaluation of the force-elongation diagram was performed similarly to Examples A to C. The results of two measurements are shown in Table 3.

Example ε _b [%] F(ε _b /2) [N] E E _lin E _nㅣ E _nl /E [%] E 3.26 2.75 3.01 2.47 0.53 17.72 E 3.95 2.85 3.42 2.82 0.59 17.37

The values in Table 3 show that in the filter material (E) produced according to the first method according to the invention there is a non-linear strain energy portion of about 17%. Example A prepared via a combination of suitable performance of hydraulic entanglement in step C5 and pre-structuring of the fibrous web by reduced application speed in step C2, i.e. a combination of the first and second methods according to the invention Comparison with C to C shows that this combination allows a higher fraction of the nonlinear strain energy of about 22% to about 28%, which can lead to better behavior when crimping. The complexity of the combined method is greater than that of the first method alone, that is, when the characteristic plastic deformability according to the invention in the transverse direction, as in example E, is obtained only through suitable performance of hydraulic entanglement in step A2. Of course it is slightly higher. Example E demonstrates that filter material according to the invention can be prepared using this simpler method.

Comparative example Z

For the production of filter material not according to the invention, the same fiber mixture as in Example D was used. The weight per unit area was still 15 g/m2, but only the machine settings typical for making conventional filter paper were used.

Three samples were taken transversely from the filter material of Comparative Example (Z) and the force-elongation diagram was recorded in a tensile test according to ISO 1924-2:2008. Evaluation of the force-elongation diagram was performed similarly to Examples A to C. The results of the three measurements are shown in Table 4.

Comparative example ε _b [%] F(ε _b /2) [N] E E _lin E _nㅣ E _nl /E [%] Z 3.21 8.38 7.22 6.71 0.52 7.17 Z 3.23 7.42 6.40 5.97 0.42 6.64 Z 3.15 7.10 5.89 5.58 0.32 5.38

The force-elongation curve of Comparative Example Z is shown in Figure 5. Even without quantitative analysis, it can already be seen that the behavior is much closer to linear elastic behavior, that the deformation is substantially restored upon load relief, and that much larger elongations and forces are required to achieve permanent deformation. In this case, the breaking load or elongation at break in the transverse direction can easily be exceeded.

Manufacture of segments and smoking articles

Paper-wrapped filter rods with a length of 100 mm and a diameter of 7.85 mm were prepared from each of the filter materials of Examples A to E and Comparative Example Z. At this time, the web width of the filter material and the machine settings during filter manufacturing were selected to result in a suction resistance of 450 ± 10 mm WG.

Filter rods could be made from the filter materials of Examples A-E and Comparative Example Z. However, during manufacturing, it was found that for the filter materials of Examples A to E the crimping process reacted much less sensitively than for Comparative Example Z to changes in machine settings and in particular to the setting of the spacing of the rollers during crimping. .

Filter cigarettes were produced from the segments of Examples A to E and Comparative Example Z according to the general methods of the prior art. This manufacturing process went off without a hitch.

This means that segments and smoking articles can be manufactured more reliably and more simply from the filter material according to the invention than from conventional hydraulically entangled non-woven fabrics or paper and, through the advantageous plastic stretching behavior, have better properties when crimping. It can be seen that the results can be achieved.

Claims (40)

A filter material for the manufacture of segments for smoking articles,
The filter material is in the form of a web and contains at least 50% and at most 100% cellulose fibers, respectively, based on the mass of the filter material,
The filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, the thickness of the layer of filter material measured in accordance with ISO 534:2011 is at least 25 ㎛ and at most 1000 ㎛, the filter material has Having a transverse direction orthogonal to the machine direction in the plane of the web of material, the filter material has a non-linear portion of the strain energy absorbed by the filter material up to half its elongation at break in a transverse tensile test according to ISO 1924-2:2008. A filter material with a characteristic plastic deformability in the transverse direction, characterized in that at least 10% and at most 50% of the total strain energy absorbed by the filter material up to half of this elongation at break. 2. The filter material of claim 1, wherein the filter material is a hydraulically entangled non-woven fabric or paper. Filter according to claim 1 or 2, wherein the proportion of cellulosic fibers in the filter material is at least 60% and at most 100%, preferably at least 70% and at most 95%, respectively, based on the mass of said filter material. ingredient. 4. The filter material of any one of claims 1 to 3, wherein the cellulosic fibers are formed from pulp fibers, fibers of regenerated cellulose, or mixtures thereof. 5. The method according to claim 4, wherein the pulp fibers are from coniferous trees or coniferous trees, deciduous trees or deciduous forests, or other plants, especially hemp, flax, jute, hemp, kenaf, kapok, coconut, abaca, sisal, bamboo. , from cotton, or from esparto grass; These filter materials are formed from a mixture of pulp fibers from various sources. 6. The method according to claim 4 or 5, wherein the proportion of regenerated cellulose fibers is at least 5% and at most 50%, preferably at least 10% and at most 45%, respectively, based on the mass of the filter material. Filter material, with a minimum of 15% and a maximum of 40%. Filter according to claim 4 , wherein the regenerated cellulose fibers are at least partially formed of viscose fibers, modal fibers, Lyocell® fibers, Tencel® fibers or mixtures thereof. ingredient. 8. Filter material according to any one of claims 1 to 7, wherein the weight per unit area of the filter material is at least 18 g/m2 and at most 55 g/m2, preferably at least 20 g/m2 and at most 50 g/m2. 9. The filter material according to any one of claims 1 to 8, wherein the non-linear portion of the strain energy absorbed by the filter material breaks in a transverse tensile test according to ISO 1924-2:2008 up to half the elongation at break. Transverse direction, characterized in that at least 15% and at most 40% of the total strain energy absorbed by the filter material up to half of the elongation, preferably at least 15% and at most 35%, especially at least 18% and at most 32%. A filter material having characteristic plastic deformability. 10. The filter material according to any one of claims 1 to 9, wherein the filter material comprises alkyl ketene dimer (AKD), acid anhydride, especially alkenyl succinic anhydride (ASA), polyvinyl alcohol, wax, fatty acid, starch, starch. A filter material containing at least one additive selected from the group consisting of derivatives, carboxymethyl cellulose, alginate, chitosan, wetting agents, or pH value adjusting substances, especially organic or inorganic acids or bases, or mixtures of two or more of these additives. 11. The filter material according to any one of claims 1 to 10, wherein the filter material comprises citrate, especially trisodium citrate or tripotassium citrate, malate, tartrate, acetate, especially sodium or potassium acetate, nitrate, succinate. At least one additive selected from the group consisting of nates, fumarates, gluconates, glycolates, lactates, oxalates, salicylates, α-hydroxycaprylate, phosphates, polyphosphates, chlorides and sodium bicarbonate, or Filter material containing a mixture of two or more of these additives. 12. The method according to any one of claims 1 to 11, wherein the filter material is at least selected from the group consisting of triacetin, propylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol and triethyl citrate. Filter material containing one substance or a mixture of two or more of these substances. 13. Filter material according to any one of claims 1 to 12, wherein at least some of the cellulose fibers are filled with filler, which filler is preferably formed from mineral particles, in particular calcium carbonate particles. 14. The method according to any one of claims 1 to 13, wherein the thickness of the layer of filter material, measured according to ISO 534:2011, is at least 30 μm and at most 800 μm, preferably at least 35 μm and at most 600 μm. , filter material. 15. The method according to any one of claims 1 to 14, wherein the width-related tensile strength of the filter material in the transverse direction, measured according to ISO 1924-2:2008, is at least 0.05 kN/m and at most 5 kN/m, Very preferably a filter material of at least 0.07 kN/m and at most 4 kN/m. 16. The filter material according to claim 1, wherein the transverse elongation at break, measured according to ISO 1924-2:2008, is at least 0.5% and at most 50%, preferably at least 0.8% and Up to 40% of filter material. A segment for a smoking article comprising a laterally gathered filter material and a wrapper material, each filter material containing at least 50% and at most 100% cellulosic fibers based on the mass of the filter material,
The filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured in accordance with ISO 534:2011 is at least 25 ㎛ and at most 1000 ㎛, wherein the filter material is a filter material For a filter material in the uncaughtered state with a gathered transverse direction, the non-linear part of the strain energy absorbed by the filter material up to half the elongation at break is less than the elongation at break in the transverse tensile test according to ISO 1924-2:2008. Segments for smoking articles with characteristic plastic deformability in the transverse direction, characterized in that at least 10% and at most 50% of the total strain energy absorbed by the filter material by half. 18. A segment according to claim 17, wherein the filter material has one or more of the additional features defined in claims 2 to 16. 19. The method of claim 17 or 18, wherein the segments are cylindrical with a diameter of at least 3 mm and at most 10 mm, preferably at least 4 mm and at most 9 mm, and very preferably at least 5 mm and at most 8 mm. , and/or said segment has a length of at least 4 mm and at most 40 mm, preferably at least 6 mm and at most 35 mm, and very preferably at least 10 mm and at most 28 mm. 20. The method according to any one of claims 17 to 19, wherein the suction resistance of the segment according to ISO 6565:2015 per length of the segment is at least 1 mmWG/mm and at most 12 mmWG/mm, preferably at least 2 mmWG/mm and segments for smoking articles up to 10 mmWG/mm. 21. A segment according to any one of claims 17 to 20, wherein the wrapper material of the segment is formed of paper or film. 22. The method according to any one of claims 17 to 21, wherein the wrapper material of the segments has a unit according to ISO 536:2019 of at least 20 g/m2 and at most 150 g/m2, preferably at least 30 g/m2 and at most 130 g/m2. A segment for a smoking article having a weight per area. Method for producing a segment according to any one of claims 17 to 22, wherein the filter material according to any one of claims 1 to 16 is crimped or pleated, preferably crimped or pleated. A method of making a segment, wherein a continuous tow is formed from machined filter material, said tow of crimped or pleated filter material is wrapped with a wrapper material, and the wrapped tow is cut into individual bars of defined length. A smoking article comprising a segment containing an aerosol-forming material and a segment according to any one of claims 17 to 22,
A smoking article according to any one of claims 17 to 22, wherein the segment preferably forms the segment of the smoking article located closest to the mouth end. 25. A smoking article according to claim 24, wherein the smoking article is a filter cigarette and the aerosol-forming material is or contains tobacco. 25. The smoking article according to claim 24, wherein the smoking article is a smoking article in which the aerosol-forming material is heated but not combusted when used in accordance with the instructions, and the aerosol-forming material is preferably selected from the group consisting of tobacco, regenerated tobacco, nicotine, glycerol, and propylene glycol. A smoking article comprising a material selected from the group consisting of or mixtures thereof. 27. A smoking article according to claim 26, wherein the aerosol-forming material is in liquid form and is located in a corresponding container within the smoking article. A method of manufacturing a filter material, which involves the following steps:
A1 - supplying a fibrous web comprising cellulosic fibers and having a machine direction and a transverse direction orthogonal to this machine direction in the web plane;
A2 - a step of hydraulic entanglement of the fiber web by means of a water jet directed towards the fiber web, to produce a hydraulically entangled fiber web; and
A3 - drying the hydraulically entangled fiber web,
In step A1, the amount or proportion of cellulosic fibers in the fibrous web is selected such that after drying in step A3 the filter material contains at least 50% and at most 100% cellulosic fibers based on the mass of the filter material;
In step A2, the number, pressure or arrangement of the water jets is such that up to half of the elongation at break is absorbed by the filter material in a transverse tensile test according to ISO 1924-2:2008, performed on the filter material after drying in step A3. It is selected to give the filter material a characteristic plastic deformability in the transverse direction, characterized in that the non-linear part of the strain energy is at least 10% and at most 50% of the total strain energy absorbed by the filter material up to half the elongation at break; ,
After drying in step A3, the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 after drying in step A3 is at least 25 μm and Method for producing filter material up to 1000 μm. 29. Method according to claim 28, wherein a plurality of water jets are used to carry out the hydraulic entanglement in step A2, these water jets being arranged in at least one row transverse to the machine direction of the fibrous web. 30. The method of claim 29, wherein the hydraulic entanglement in step A2 is carried out via at least two rows of water jets directed towards the fibrous web, preferably with at least one row of water jets acting on each of the two sides of the fibrous web. Method of manufacturing filter material. Method of manufacturing filter material, with the following steps (B1 to B4):
B1 - Preparing an aqueous suspension comprising cellulose fibers;
B2 - applying the suspension of step B1 onto the circular wire;
B3 - dewatering the suspension through a circular wire to form the fibrous web;
B4 - drying the fiber web of step B3,
In step B1, the amount or proportion of cellulose fibers is selected such that after drying in step B4 the filter material contains at least 50% and at most 100% cellulose fibers based on the mass of this filter material,
In step B3, the machine direction of the fiber web is defined by the running direction of the wire, and the transverse direction is defined by a direction orthogonal to the machine direction in the plane of the fiber web,
In step B2, the suspension is applied onto the circulating wire at a speed lower than that of this circulating wire, and this speed difference is carried out on the filter material after drying in step B4, according to ISO 1924-2:2008. Characterized in that in the transverse tensile test according to the non-linear part of the strain energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total strain energy absorbed by the filter material up to half the elongation at break. selected so as to impart characteristic plastic deformability in the transverse direction to the filter material,
The filter material after drying in step B4 has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 after drying in step B4 is at least 25 g/m2. ㎛ and up to 1000 ㎛, method for producing filter material A method of manufacturing a filter material, comprising the following steps (C1 to C6):
C1 - Preparing an aqueous suspension comprising cellulose fibers;
C2 - applying the suspension from step C1 onto the circulating wire;
C3 - dewatering the suspension through a circular wire to form a fibrous web;
C4 - the fiber web of step C3 is transferred onto a support wire;
C5 - hydraulic entanglement of the fiber web by means of a water jet directed towards the fiber web, to produce a hydraulically entangled fiber web; and
C6 - a drying step of drying the hydraulically entangled fiber web,
In step C1, the amount or proportion of cellulose fibers is selected such that after drying in step C6 the filter material contains at least 50% and at most 100% cellulose fibers based on the mass of this filter material,
In step C3, the machine direction of the fiber web is defined by the traveling direction of the wire, and the transverse direction is defined by a direction orthogonal to the machine direction in the plane of the fiber web,
After drying in step C6 the filter material has a weight per unit area of at least 15 g/m2 and at most 60 g/m2, and the thickness of the layer of filter material measured according to ISO 534:2011 after drying in step C6 is at least 25 μm and The maximum is 1000㎛,
In step C2, the suspension is applied onto the circulating wire at a speed lower than that of the circulating wire, the difference between the velocities in step C2 and the number, pressure and/or arrangement of the water jets in step C5 being: In a transverse tensile test according to ISO 1924-2:2008, performed on the filter material after drying in step C6, the non-linear part of the strain energy absorbed by the filter material up to half the elongation at break of the filter material up to half the elongation at break. A method for producing a filter material, wherein the filter material is selected to be endowed with a characteristic plastic deformability in the transverse direction, characterized in that it is at least 10% and at most 50% of the total strain energy absorbed by the filter material. 33. The process according to claim 31 or 32, wherein the aqueous suspension in step B1 or C1 has a solids content of at most 3.0%, very preferably at most 1.0%, very particularly preferably at most 0.2% and especially at most 0.05%. Method of manufacturing filter material. 34. The process according to any one of claims 31 to 33, wherein the endless wires of steps B2 and B3 or steps C2 and C3 are inclined upwards to the horizontal in the machine direction of the fiber web by an angle of at least 3° and at most 40°. , preferably inclined upwards by an angle of at least 5° and at most 30°, very preferably by an angle of at least 15° and at most 25°. 35. The method according to any one of claims 31 to 34, wherein the method further comprises the step of creating a pressure difference between the two sides of the circulating wire to support the dewatering step of the suspension in step B3 or step C3, The method of producing a filter material, wherein the pressure difference is very preferably created by a vacuum box or a suitably formed foil. 36. Method according to any one of claims 28 to 35, wherein the drying step in steps A3, B4 or C6 is carried out at least partially by contact with hot air, infrared radiation or microwave radiation. 37. A method according to any one of claims 28 to 36, wherein the filter material produced according to the method is a filter material according to any one of claims 1 to 16. 38. The method of any one of claims 28 to 37, wherein the method comprises the additional step of applying one or more additives onto the fibrous web, wherein the one or more additives include alkyl ketene dimer (AKD), acid Anhydrides, especially alkenyl succinic anhydride (ASA), polyvinyl alcohol, waxes, fatty acids, starches, starch derivatives, carboxymethyl cellulose, alginates, chitosan, wetting agents, or pH value adjusting substances, especially organic or inorganic acids or bases. A method for producing a filter material selected from the group consisting of: 39. The method according to any one of claims 28 to 38, wherein the manufacturing method comprises the additional step of applying one or more additives onto the fibrous web, wherein the one or more additives are citrate, in particular trisodium citrate or citric acid. Tripotassium, malate, tartrate, acetate, especially sodium or potassium acetate, nitrate, succinate, fumarate, gluconate, glycolate, lactate, oxalate, salicylate, α-hydroxycaprylate. , phosphate, polyphosphate, chloride and sodium bicarbonate, or mixtures thereof. The method of claim 38 or 39, wherein the one additive or plural additives
- Between stage A2 and stage A3, or
- between stage B3 and stage B4, or
- is applied between steps C3 and C4, or between steps C4 and C5, or between steps C5 and C6, or
- The above one additive or plural additives
- After step A3, or
- After step B4, or
- applied after step C6,
A method for producing a filter material, wherein the further step of drying the fibrous web is then carried out.

Images