Hydroentangled filter material for smoking articles having improved expansion behaviour

Abstract

Shown is a hydroentangled nonwoven for manufacturing a segment for a smoking article, wherein the hydroentangled nonwoven is web-shaped and contains at least 50% and at most 100% cellulose fibers, each with respect to the mass of the hydroentangled nonwoven, wherein the hydroentangled nonwoven has a basis weight of at least 15 g/m 2 and at most 60 g/m 2 , wherein the hydroentangled nonwoven has a machine direction and a cross direction orthogonal thereto and lying in the plane of the web of the hydroentangled nonwoven, and wherein the hydroentangled nonwoven 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 hydroentangled nonwoven up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the hydroentangled nonwoven up to half the elongation at break.

1 . Hydroentangled nonwoven for manufacturing a segment for a smoking article, wherein the hydroentangled nonwoven is web-shaped and contains at least 50% and at most 100% cellulose fibers, each with respect to the mass of the hydroentangled nonwoven,
 wherein the hydroentangled nonwoven has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , wherein the hydroentangled nonwoven has a machine direction and a cross direction orthogonal thereto and lying in the plane of the web of the hydroentangled nonwoven, and wherein the hydroentangled nonwoven 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 hydroentangled nonwoven up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the hydroentangled nonwoven up to half the elongation at break.   
     
     
         2 . Hydroentangled nonwoven according to  claim 1 , in which the proportion of the cellulose fibers in the hydroentangled nonwoven is at least 70% and at most 95%, each with respect to the mass of the hydroentangled nonwoven. 
     
     
         3 . Hydroentangled nonwoven according to  claim 1 , in which the cellulose fibers are formed by pulp fibers or fibers from regenerated cellulose, or mixtures thereof. 
     
     
         4 . (canceled) 
     
     
         5 . Hydroentangled nonwoven according to  claim 3 , in which the proportion of fibers from regenerated cellulose is at least 5% and at most 50% with respect to the mass of the hydroentangled nonwoven. 
     
     
         6 . (canceled) 
     
     
         7 . Hydroentangled nonwoven according to  claim 1 , with a basis weight of at least 20 g/m 2  and at most 50 g/m 2 . 
     
     
         8 . Hydroentangled nonwoven according to  claim 1 , wherein the hydroentangled nonwoven 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 hydroentangled nonwoven up to half the elongation at break is at least 18% and at most 32% of the total deformation energy absorbed by the hydroentangled nonwoven up to half the elongation at break. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . Hydroentangled nonwoven 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. 
     
     
         12 . Hydroentangled nonwoven according to  claim 1 , in which at least a portion of the cellulose fibers is loaded with a filler, wherein the filler is formed calcium carbonate particles. 
     
     
         13 . Hydroentangled nonwoven according to  claim 1 , in which the thickness of one layer of the hydroentangled nonwoven, measured in accordance with ISO 534:2011, is at least 35 μm and at most 600 μm. 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . Segment for a smoking article, comprising a hydroentangled nonwoven gathered in the cross direction and a wrapper material, wherein the hydroentangled nonwoven contains at least 50% and at most 100% cellulose fibers, each with respect to the mass of the hydroentangled nonwoven,
 wherein the hydroentangled nonwoven has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 , wherein the hydroentangled nonwoven has a cross direction in which the hydroentangled nonwoven is gathered, and wherein in the non-gathered state, the hydroentangled nonwoven 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 hydroentangled nonwoven up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the hydroentangled nonwoven up to half the elongation at break.   
     
     
         17 . Segment according to  claim 16 , in which the hydroentangled nonwoven has one or more of the features that are defined in  claim 2 . 
     
     
         18 . Segment according to  claim 16 , 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. 
     
     
         19 . Segment according to  claim 16 , 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. 
     
     
         20 . (canceled) 
     
     
         21 . Segment according to  claim 16 , 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 . 
     
     
         22 . Process for manufacturing a segment according to  claim 16 , in which the hydroentangled nonwoven according to  claim 1  is crimped or pleated, a continuous tow produced from crimped or pleated hydroentangled nonwoven is formed, the tow of crimped or pleated hydroentangled nonwoven is wrapped with a wrapper material and the wrapped tow is cut into individual rods of a defined length. 
     
     
         23 . Smoking article, comprising a segment which contains an aerosol-forming material and a segment according to  claim 16 . 
     
     
         24 . Smoking article according to  claim 23 , wherein the smoking article is a filter cigarette, and the aerosol-forming material is or contains tobacco. 
     
     
         25 . Smoking article according to  claim 23 , 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 selected from the group consisting of tobacco, reconstituted tobacco, nicotine, glycerol, propylene glycol or mixtures thereof. 
     
     
         26 . Smoking article according to  claim 25 , in which the aerosol-forming material is present in liquid form and is located in a corresponding container in the smoking article. 
     
     
         27 . Process for manufacturing a hydroentangled nonwoven, 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 proportion of cellulose fibers in the fiber web is selected such that after drying in step A3, the hydroentangled nonwoven contains at least 50% and at most 100% cellulose fibers, with respect to the mass of the hydroentangled nonwoven and   wherein steps A1 and A2 are carried out such that the hydroentangled nonwoven is provided with a characteristic plastic deformability in the cross direction, which is characterized in that in a tensile test in the cross direction carried out in accordance with ISO 1924-2:2008 on the hydroentangled nonwoven after drying in step A3, the nonlinear portion of the deformation energy absorbed by the hydroentangled nonwoven up to half the elongation at break is at least 10% and at most 50% of the total deformation energy absorbed by the hydroentangled nonwoven up to half the elongation at break,   and wherein after drying in step A3, the hydroentangled nonwoven has a basis weight of at least 15 g/m 2  and at most 60 g/m 2 .   
     
     
         28 . (canceled) 
     
     
         29 . Process according to  claim 27 , in which the hydroentangling in step A2 is carried out by at least two rows of water jets directed onto the fiber web, wherein at least one row of water jets acts on each of the two sides of the fiber web. 
     
     
         30 . (canceled) 
     
     
         31 . Process according to  claim 27 , wherein the hydroentangled nonwoven manufactured according to this process is a hydroentangled nonwoven according to  claim 1 . 
     
     
         32 . Process according to  claim 27 , in which the step A1 for providing a fiber web comprises the following sub-steps B1 to B3:
 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 said fiber web,   wherein in step B1, the amount or the proportion of cellulose fibers is selected such that after drying in step A3, the hydroentangled nonwoven contains at least 50% and at most 100% cellulose fibers, with respect to the mass of the hydroentangled nonwoven,   wherein said machine direction of the fiber web is defined by the running direction of the wire in step B3 and said cross direction is defined by the direction orthogonal thereto lying in the plane of the fiber web, and   wherein in step B2, the suspension is applied to the running wire at a speed which is lower than the speed of the running wire.   
     
     
         33 . Process according to  claim 32 , in which the aqueous suspension in step B1 has a solids content of at most 0.2%. 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . Process according to  claim 27 , 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 anhydrides (ASA), polyvinyl alcohol, waxes, fatty acids, starch, starch derivatives, carboxy methyl cellulose, alginates, chitosan, wet strength agents or substances for adjusting the pH, organic or inorganic acids or bases, and mixtures thereof. 
     
     
         37 . (canceled) 
     
     
         38 . Process according to  claim 36 , in which the one or more additives is or are applied between the steps A2 and A3, or after step A3, followed by a further step of drying the fiber web. 
     
     
         39 . Smoking article according to  claim 23 , wherein said segment according to  claim 16  is the segment of the smoking article located closest to the mouth end.