Filter material for smoking articles having improved expansion behaviour

Abstract

Shown is a filter material for manufacturing a segment for a smoking article, wherein the filter material is web-shaped and contains at least 50% and at most 100% cellulose fibers, each with respect to the mass of the filter material, wherein the filter material has a basis weight of at least 15 g/m2 and at most 60 g/m2, wherein the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, is at least 25 μm and at most 1000 μm, wherein the filter material has a machine direction and a cross direction orthogonal thereto and lying in the plane of the web of the filter material, and wherein the filter material has a characteristic plastic deformability in the cross direction which is characterized in that in a tensile test in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the filter material up to half the elongation at break.

1 . Filter material for manufacturing a segment for a smoking article, wherein the filter material is web-shaped and contains at least 50% and at most 100% cellulose fibers, each with respect to the mass of the filter material,
 wherein the filter material has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , wherein the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, is at least 25 μm and at most 1000 μm, wherein the filter material has a machine direction and a cross direction orthogonal thereto and lying in the plane of the web of the filter material, and wherein the filter material has a characteristic plastic deformability in the cross direction which is characterized in that in a tensile test in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the filter material up to half the elongation at break.   
     
     
         2 . Filter material according to  claim 1 , in which the filter material is a hydroentangled nonwoven or a paper. 
     
     
         3 . Filter material according to  claim 1 , in which the proportion of cellulose fibers in the filter material is at least 70% and at most 95%, each with respect to the mass of the filter material. 
     
     
         4 . Filter material according to  claim 1 , in which the cellulose fibers are formed by pulp fibers or fibers from regenerated cellulose or mixtures thereof. 
     
     
         5 . (canceled) 
     
     
         6 . Filter material according to  claim 4 , in which the proportion of fibers produced from regenerated cellulose is at least 5% and at most 50% with respect to the mass of the filter material. 
     
     
         7 . (canceled) 
     
     
         8 . Filter material according to  claim 1 , with a basis weight of at least 20 g/m 2  and at most 50 g/m 2 . 
     
     
         9 . Filter material according to  claim 1 , wherein the filter material has a characteristic plastic deformability in the cross direction which is characterized in that in said tensile test in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 18% and at most 32% of the total deformation energy absorbed by the filter material up to half the elongation at break. 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . Filter material according to  claim 1 , which contains at least one substance selected from the group consisting of triacetin, propylene glycol, sorbitol, glycerol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol and triethyl citrate, or a mixture of two or more of the at least one substances. 
     
     
         13 . Filter material according to  claim 1 , in which at least a portion of the cellulose fibers is loaded with a filler, wherein the filler is formed by calcium carbonate particles. 
     
     
         14 . Filter material according to  claim 1 , in which the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, is least 35 μm and at most 600 μm. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . Segment for a smoking article, comprising a filter material gathered in the cross direction, wherein the filter material contains at least 50% and at most 100% cellulose fibers, each with respect to the mass of the filter material,
 wherein the filter material has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , wherein the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, is at least 25 μm and at most 1000 μm, wherein the filter material has a cross direction, in which the filter material is gathered, and wherein the filter material in the non-gathered state has a characteristic plastic deformability in the cross direction which is characterized in that in a tensile test in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the filter material up to half the elongation at break.   
     
     
         18 . Segment according to  claim 17 , in which the filter material has one or more of the features that are defined in  claim 2 . 
     
     
         19 . Segment according to  claim 17 , wherein the segment is cylindrical with a diameter of at least 4 mm and at most 9 mm, and/or wherein the segment has a length of at least 6 mm and at most 35 mm. 
     
     
         20 . Segment according to  claim 17 , wherein the draw resistance of the segment in accordance with ISO 6565:2015 per unit length of the segment is at least 1 mmWG/mm and at most 12 mmWG/mm. 
     
     
         21 . (canceled) 
     
     
         22 . Segment according to  claim 17 , wherein the wrapper material has a basis weight in accordance with ISO 536:2019 of at least 30 g/m 2  and at most 130 g/m 2 . 
     
     
         23 . Process for manufacturing a segment according to  claim 17 , in which the filter material according to  claim 1  is crimped or pleated, a continuous tow of crimped or pleated filter material is formed and the tow of crimped or pleated filter material is wrapped with a wrapper material and the wrapped tow is cut into individual rods of a defined length. 
     
     
         24 . Smoking article, comprising a segment, which contains an aerosol-forming material, and a segment according to  claim 17 . 
     
     
         25 . Smoking article according to  claim 24 , wherein the smoking article is a filter cigarette, and the aerosol-forming material is or contains tobacco. 
     
     
         26 . Smoking article according to  claim 24 , wherein the smoking article is a smoking article in which, during its intended use, the aerosol-forming material is only heated but not burned, wherein the aerosol-forming material comprises a material which is selected from the group consisting of tobacco, reconstituted tobacco, nicotine, glycerol, propylene glycol or mixtures thereof. 
     
     
         27 . Smoking article according to  claim 26 , in which the aerosol-forming material is present in liquid form and located in a corresponding container in the smoking article. 
     
     
         28 . Process for manufacturing a filter material, wherein the process comprises the following steps:
 A1—providing a fiber web comprising cellulose fibers, which has a machine direction and a cross direction orthogonal thereto and lying in the web plane,   A2—hydroentangling the fiber web by water jets directed onto the fiber web to produce a hydroentangled fiber web, A3—drying the hydroentangled fiber web,   wherein in step A1, the amount or the proportion of cellulose fibers in the fiber web is selected such that after drying in step A3, the filter material contains at least 50% and at most 100% cellulose fibers, with respect to the mass of the filter material, and wherein in step A2, the number, pressure and/or arrangement of the water jets is selected such that the filter material is provided with a characteristic plastic deformability in the cross direction, which is characterized in that in a tensile test carried out on the filter material after drying in step A3 in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the filter material up to half the elongation at break,   wherein, after drying in step A3, the filter material has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , and wherein the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, after drying in step A3, is at least 25 μm and at most 1000 μm.   
     
     
         29 . (canceled) 
     
     
         30 . Process according to  claim 28 , in which the hydroentangling in step A2 is carried out by at least two rows of water jets directed onto the fiber web, wherein the water jets act on each of the two sides of the fiber web. 
     
     
         31 . Process for manufacturing a filter material, which comprises the following steps B1 to B4:
 B1—producing an aqueous suspension comprising cellulose fibers,   B2—applying the suspension from step B1 to a running wire,   B3—de-watering the suspension through the running wire to form a fiber web,   B4—drying the fiber web from step B3,   wherein in step B1, the amount or the 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, with respect to the mass of the filter material, wherein a machine direction of the fiber web is defined by the running direction of the wire in step B3 and a cross direction is defined by a direction orthogonal thereto and lying in the plane of the fiber web, and   wherein in step B2, the suspension is applied to the running wire with a speed which is lower than the speed of the running wire and the difference between these speeds is selected such that the filter material is provided with a characteristic plastic deformability in the cross direction, which is characterized in that in a tensile test carried out on after drying in step B4, the filter material in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the filter material up to half the elongation at break,   wherein, after drying in step B4, the filter material has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , and wherein the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, after drying in step B4, is at least 25 μm and at most 1000 μm.   
     
     
         32 . Process for manufacturing a filter material, which comprises the following steps C1 to C6:
 C1—producing an aqueous suspension comprising cellulose fibers,   C2—applying the suspension from step C1 to a running wire,   C3—de-watering the suspension through the running wire, to form a fiber web,   C4—transferring the fiber web from step C3 to a support wire,   C5—hydroentangling the fiber web by water jets directed onto the fiber web to form a hydroentangled fiber web,   C6—drying the hydroentangled fiber web,   wherein, in step C1, the amount or the 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, with respect to the mass of the filter material, and wherein in step C3, a machine direction of the fiber web is defined by the running direction of the wire and a cross direction is defined by a direction orthogonal thereto and lying in the plane of the fiber web,   wherein, after drying in step C6, the filter material has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , and wherein the thickness of one layer of the filter material, measured in accordance with ISO 534:2011, after drying in step C6, is at least 25 μm and at most 1000 μm,   wherein in step C2, the suspension is applied to the running wire with a speed which is lower than the speed of the running wire and the difference between these speeds in step C2 and the number, pressure and/or arrangement of the water jets in step C5 are selected such that the filter material is provided with a characteristic plastic deformability in the cross direction, which is characterized in that in a tensile test carried out on after drying in step C6, the filter material in the cross direction in accordance with ISO 1924-2:2008, the nonlinear portion of the deformation energy absorbed by the filter material up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the filter material up to half the elongation at break.   
     
     
         33 . Process according to  claim 31 , in which the aqueous suspension in step B1 or C1, respectively, has a solids content of at most 0.2%. 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . (canceled) 
     
     
         37 . Process according to  claim 28 , wherein the filter material manufactured according to this process is a filter material according to  claim 1 . 
     
     
         38 . Process according to  claim 28 , which comprises a further step, in which one or more additives are applied onto the fiber web, wherein the one or more additives is or are selected from the group consisting of alkyl ketene dimers (AKD), acid anhydrides, alkenyl succinic acid anhydride (ASA), polyvinyl alcohol, waxes, fatty acids, starch, starch derivatives, carboxy methyl cellulose, alginates, chitosan, wet strength agents or substances to adjust the pH, organic or inorganic acids or bases, and mixtures thereof. 
     
     
         39 . (canceled) 
     
     
         40 . Process according to  claim 38 , in which the one or more additives is or are applied
 between the steps A2 and A3, or   between the steps B3 and B4, or   between the steps C3 and C4 or C4 and C5 or C5 and C6, or   wherein the one or more additives are applied   after the step A3, or   after the step B4, or   after the step C6,   followed by a further step of drying the fiber web.   
     
     
         41 . Smoking article according to  claim 24 , wherein said segment according to  claim 17  is the segment of the smoking article located closest to the mouth end.