Filter for smoking or vaping article comprising a two-layer material
The invention provides a material which comprises a paper substrate and a nonwoven substrate having a low density which can be used as filter for a smoking or vaping article.
1 . A filter comprising a two-layer material comprising:
a paper substrate having a density of between 500 mg/cm 3 and 200 mg/cm 3 , and
a nonwoven substrate having a density of between 7 mg/cm 3 and 60 mg/cm 3 ,
wherein the paper substrate forms a first layer, the nonwoven substrate forms a second layer, and the first layer is in contact with the second layer.
2 . The filter according to claim 1 , wherein the paper substrate to nonwoven substrate mass ratio is between 10:90 and 90:10.
3 . The filter according to claim 1 , wherein the paper substrate has a thickness of between 50 μm and 200 μm.
4 . The filter according to claim 1 , wherein the nonwoven substrate has a thickness of between 700 μm and 6000 μm.
5 . The filter according to claim 1 , wherein the nonwoven substrate comprises natural fibres chosen from wood fibres, leaf fibres, fruit fibres, seed fibres, bast fibres, stalk fibres, reed fibres, and mixtures thereof.
6 . The filter according to claim 1 , wherein the nonwoven substrate is consolidated by chemical consolidation, by needling, by hydroentanglement, or combinations thereof.
7 . The filter according to claim 1 , wherein the nonwoven substrate is capable of being obtained by a drylaid process or by an airlaid process.
8 . The filter according to claim 1 for a smoking or vaping article.
9 . A smoking article comprising a filter as defined in claim 8 .
10 . A vaping article comprising a filter as defined in claim 8 .
11 . A process for producing a filter for a smoking or vaping article as defined in claim 8 , said process comprising the following steps:
a) producing the paper substrate by a wetlaid process,
b) optionally shaping the paper substrate produced in step a),
c) producing the nonwoven substrate by a drylaid process or by an airlaid process,
d) combining the paper substrate produced in step a) or b) and the nonwoven substrate produced in step c) to produce a two-layer material,
e) forming a rod from the two-layer material produced in step d),
f) wrapping the rod with a sheet of plug wrap paper,
g) depositing an adhesive line at the junction of the sheet of plug wrap paper to obtain a rod of filtering material,
h) cutting the rod of filtering material to produce the filter.
12 . The filter according to claim 1 , wherein the paper substrate has a density of between 400 mg/cm 3 and 250 mg/cm 3 and the nonwoven substrate has a density of between 8 mg/cm 3 and 55 mg/cm 3 .
13 . The filter according to claim 1 , wherein the paper substrate to nonwoven substrate mass ratio is between 75:25 and 25:75.
14 . The filter according to claim 1 , wherein the paper substrate has a thickness of between 75 μm and 150 μm.
15 . The filter according to claim 1 , wherein the nonwoven substrate has a thickness of between 900 μm and 4700 μm.
16 . The filter according to claim 1 , wherein the nonwoven substrate is obtained by a drylaid process.
17 . The filter according to claim 1 , wherein the nonwoven substrate is obtained by an airlaid process.