Tobacco smoke filter

Abstract

A tobacco smoke filter or filter element including a nonwoven fabric, wherein the nonwoven fabric comprises: a sheet of staple fibres; and a water soluble binder; wherein the water soluble binder is uniformly coated on at least one face of the sheet of staple fibres. The filter has superior biodegradability.

1 . A tobacco smoke filter or filter element including a nonwoven fabric, wherein the nonwoven fabric comprises: a sheet of staple fibres; and a water soluble binder; wherein the water soluble binder is uniformly coated on at least one face of the sheet of staple fibres. 
     
     
         2 . A tobacco smoke filter or filter element including a nonwoven fabric, wherein the nonwoven fabric comprises: staple fibres; and a water soluble binder; wherein the water soluble binder is applied to the staple fibres in aqueous form. 
     
     
         3 . A tobacco smoke filter or filter element according to  claim 2  wherein the non woven fabric comprises a sheet of staple fibres. 
     
     
         4 . A filter or filter element according to  claim 1 , wherein the nonwoven fabric is a wet laid nonwoven fabric. 
     
     
         5 . A filter or filter element according to  claim 1  wherein the staple fibres are biodegradable. 
     
     
         6 . A filter or filter element according to  claim 1  wherein the staple fibres have the ‘Ready Biodegradability’ level of biodegradability as measured according to OECD 301B ‘Ready Biodegradability’ method (modified Sturm test). 
     
     
         7 . A tobacco smoke filter or filter element according to  claim 1  wherein the nonwoven fabric further comprises wood pulp. 
     
     
         8 . A filter or filter element according to  claim 1  wherein the staple fibres are staple fibres of cut length 4 mm to 10 mm, for example 4 to 6 mm. 
     
     
         9 . A filter or filter element according to  claim 1  wherein the staple fibres are of diameter 1.7 dtex to 3.3 dtex. 
     
     
         10 . A tobacco smoke filter or filter element according to  claim 1  wherein the staple fibres are regenerated cellulosic fibres, viscose, tencel, polyvinyl alcohol, polylactic acid, polyglycolic acid or cotton. 
     
     
         11 . A tobacco smoke filter or filter element according to  claim 1  wherein the amount of binder is 0.1% to 5% expressed as percentage of the solids level content in the finished nonwoven fabric. 
     
     
         12 . A tobacco smoke filter or filter element wherein the water soluble binder is carboxymethyl cellulose, polyvinyl alcohol, hydroxycellulose, polyethylene oxide, a natural or modified starch, a cationic starch, guar gum or derivative thereof. 
     
     
         13 . A tobacco smoke filter or filter element according to  claim 1  wherein the nonwoven fabric has basis weight 25 to 42 gsm, for example 27 to 40 gsm. 
     
     
         14 . A tobacco smoke filter or filter element according to  claim 1  further comprising a flavour enhancing additive. 
     
     
         15 . A tobacco smoke filter or filter element according to  claim 1  wherein the nonwoven fabric is the tobacco smoke filtering material. 
     
     
         16 . A tobacco smoke filter or filter element according to  claim 1  having a dispersibility wherein 95% or more, for example 96% or more, of the nonwoven fabric passes through 6.3 mm aperture screens after being subjected to EDANA Standard FG511.1 Tier 1 Dispersability Shake Flask Test (using screens of 1.6, 3.15, 6.3 and 12.5 mm aperture). 
     
     
         17 . A tobacco smoke filter or filter element according to  claim 1  wherein the non-woven fabric further comprises wood pulp in an amount of up to 20% by weight of the non-woven fabric, and the amount of binder is 0.1 to 5% expressed as percentage of the solids level content in the finished non-woven fabric. 
     
     
         18 - 20 . (canceled) 
     
     
         21 . A filter cigarette which includes a tobacco smoke filter or filter element according to  claim 1 . 
     
     
         22 - 25 . (canceled)