Filter for Smoking or Vaping Article Comprising a Nonwoven Substrate

Abstract

The present invention relates to a filter comprising a nonwoven substrate having a low density and comprising natural fibers and a binder. The filter can be used as a filter for a smoking or vaping article.

Claims

1-12. (canceled)

13. A filter comprising a nonwoven substrate comprising natural fibers and a binder, in which the natural fibers represent from 70% and 99% by weight of solids of said nonwoven substrate, the natural fibers comprising bast fibers, the binder represents from 1% and 30% by weight of solids of said nonwoven substrate, characterized in that the nonwoven substrate has a density of from 10 mg/cm.sup.3 to 60 mg/cm.sup.3.

14. The filter according to claim 13, in which the nonwoven substrate has a thickness of between 700 m and 4000 m.

15. The filter according to claim 13, in which the nonwoven substrate has a thickness of between 900 m and 3000 m.

16. The filter according to claim 13, in which the natural fibers further comprise at least one of wood fibers, leaf fibers, fruit fibers, seed fibers, stalk fibers, reed fibers, and mixtures thereof.

17. The filter according to claim 13, in which the natural fibers further comprise wood fibers chosen from lyocell fibers, viscose fibers, and mixtures thereof.

18. The filter according to claim 13, in which the binder is a water-soluble binder.

19. The filter according to claim 18, in which the binder is chosen from a polysaccharide, a cellulose derivative, a polyvinyl alcohol and mixtures thereof.

20. The filter according to claim 13 for a smoking article or a vaping article.

21. A smoking article comprising a filter as defined in claim 13.

22. A vaping article comprising a filter as defined in claim 13.

23. A process for producing a filter for a smoking or vaping article comprising a nonwoven substrate, said process comprising the following steps: a) forming a rod of nonwoven substrate from a nonwoven substrate, b) wrapping the rod of nonwoven substrate with a sheet of plug wrap paper, c) depositing an adhesive line, joining the sheet of plug wrap paper to obtain a rod of filtering material, d) cutting the rod of filtering material to produce the filter, wherein the nonwoven substrate is as defined in claim 13 or is obtained by a process comprising the following steps: i) producing a web from natural fibers by an airlaid process, ii) introducing the binder into the web, and iii) drying the web resulting from step ii) to obtain the nonwoven substrate.

24. The process according to claim 23 in which, after step iii) and before step a), the nonwoven substrate is packed as bobbin, as roll by the spooling process or in paperboard by the festooning process.

25. The filter according to claim 13, wherein the nonwoven substrate has a density of from 10 mg/cm.sup.3 to 50 mg/cm.sup.3.

26. The filter according to claim 13, wherein the nonwoven substrate has a thickness of from 1200 m to 4000 m.

27. The filter according to claim 13, wherein the filter has a density of from 100 mg/cm.sup.3 to 200 mg/cm.sup.3.

28. The filter according to claim 13, wherein the nonwoven substrate is formed from an airlaid process.

Description

EXAMPLES

Example 1: Manufacture of the Nonwoven Substrate

[0095] In the Examples, the air permeability is determined using FX3300 Lab Air IV Air permeability tester. During the measurements, the tested web is placed under the measurement head and we measured the air flow passing through the web at pressure drop of 200 Pa over the area of 20 cm.sup.2. The permeability is measured in [cm.sup.3/cm.sup.2/sec]. For each sample, three measurements were made and the indicated air permeability is the average value.

Example 1.1: Nonwoven Substrate Prepared by an Airlaid Process and Comprising 92% By Weight of Solids of Said Nonwoven Substrate of Softwood Fluff Pulp and 8% By Weight of Solids of Said Nonwoven Substrate of Starch

[0096] The softwood fluff pulp was ground and deposited on a forming fabric by an airlaid process to obtain a web. A solution comprising 0.7% solids content of starch (Perfectafilm X115 manufactured by Avebe) is sprayed onto both sides of the web. The sprayed web is then dried by infrared and hot air oven at a temperature of between 180 C. and 190 C.

[0097] The nonwoven substrate obtained has a density of 30 mg/cm.sup.3, a thickness of 1530 m, a grammage of 46 g/m.sup.2 and an air permeability of 440 cm.sup.3.Math.cm.sup.2.Math.sec.sup.1.

Example 1.2: Nonwoven Substrate Prepared by an Airlaid Process and Comprising 85% by Weight of Solids of Said Nonwoven Substrate of Softwood Fluff Pulp and 15% by Weight of Solids of Said Nonwoven Substrate of Starch

[0098] The nonwoven substrate is obtained by the process described in example 1.1 with 37 g/m.sup.2. Before spraying with starch with 1.27% solids content, the web was compacted with a pressure of 1 bar. The content of binder in the web after drying is 15%.

[0099] The nonwoven substrate obtained has a density of 41 mg/cm.sup.3, a thickness of 900 m, a grammage of 37 g/m.sup.2 and an air permeability of 345 cm.sup.3.Math.cm.sup.2.Math.sec.sup.1.

Example 1.3: Nonwoven Substrate Prepared by an Airlaid Process and Comprising 95% by Weight of Solids of Said Nonwoven Substrate of Softwood Fluff Pulp and 5% by Weight of Solids of Said Nonwoven Substrate of Carboxymethyl Cellulose

[0100] The nonwoven substrate is obtained by the process described in example 1.1. A solution comprising 0.7% solids content of carboxymethyl cellulose (Blanose 7LCF with a degree of substitution of 0.65-0.9, manufactured by Ashland) is sprayed onto both sides of the web. The content of binder in the web after drying is 5%.

[0101] The nonwoven substrate obtained has a density of 21 mg/cm.sup.3, a thickness of 2340 m, a grammage of 51 g/m.sup.2 and an air permeability of 407 cm.sup.3.Math.cm.sup.2.Math.sec.sup.1.

Example 1.4: Nonwoven Substrate Prepared by an Airlaid Process and Comprising 92% by Weight of Solids of Said Nonwoven Substrate of Softwood Fluff Pulp and 8% by Weight of Solids of Said Nonwoven Substrate of Highly Hydrolyzed Polyvinyl Alcohol

[0102] The nonwoven substrate is obtained by the process described in example 1.1. A solution comprising 0.8% solids content of polyvinyl alcohol (Elvanol 71-30 with a degree of hydrolysis of 99.5%, manufactured by Kuraray) is sprayed onto both sides of the web. The content of binder in the web after drying is 8%.

[0103] The nonwoven substrate obtained has a density of 21 mg/cm.sup.3, a thickness of 1900 m, a grammage of 40 g/m.sup.2 and an air permeability of 403 cm.sup.3.Math.cm.sup.2.Math.sec.sup.1.

Example 1.5: Nonwoven Substrate Prepared by an Airlaid Process and Comprising 92% by Weight of Solids of Said Nonwoven Substrate of Softwood Fluff Pulp and 8% by Weight of Solids of Said Nonwoven Substrate of Partially Hydrolyzed Polyvinyl Alcohol

[0104] The nonwoven substrate is obtained by the process described in example 1.1. A solution comprising 0.87% solids content of polyvinyl alcohol (Poval 6-88 with a degree of hydrolysis of 88%, manufactured by Kurary) is sprayed onto both sides of the web. The content of binder in the web after drying is 8%.

[0105] The nonwoven substrate obtained has a density of 24 mg/cm.sup.3, a thickness of 1690 m and a grammage of 41 g/m.sup.2 and an air permeability of 480 cm.sup.3.Math.cm.sup.2.Math.sec.sup.1.

Example 2: Manufacture and Characterization of Filters for a Smoking Article

[0106] Filters for a smoking article were manufactured with the substrates of examples 1.1 to 1.4 by a standard method for manufacturing filters without passage through a crimping machine. A nonporous plug wrap paper was used to wrap the rods of nonwoven filtering material.

[0107] The filters of the invention were compared with the paper filter and with the commercial cellulose acetate filter. The paper filter was made using a standard method for manufacturing filters by crimping the substrate CF 36 of 36 g/m.sup.2 and 100 m thickness. The filters obtained for each term were cut into 21-mm sticks.

[0108] The characteristics of the filters are given in table 1 below.

TABLE-US-00001 TABLE 1 Commercial Filter Filter Filter Filter Filter cellulose comprising the comprising the comprising the comprising the made from acetate substrate of substrate of substrate of substrate of crimped filter example 1-1 example 1-2 example 1-3 example 1-4 CF36 paper Length of the filters [mm] 21 Diameter of the filters [mm] 7.8 Weight of the filters [mg] 139 5 124 1 151 1 118 1 120 1 221 1 Density of the filters [mg/cm.sup.3] 138 127 154 120 111 226

Example 3: Manufacture and Characterization of Cigarettes

[0109] Cigarettes were prepared using the filters described in example 2. To form the cigarettes, the rods of tobacco were assembled with the filters using tipping paper. A commercial American blend tobacco was used to form the rods of tobacco. The cigarettes were prepared with a pressure drop similar to that of the commercial cigarette. The ventilation of the cigarettes was blocked.

[0110] The cigarettes prepared were smoked on a Borgwaldt RM20 smoking machine in accordance with the standard ISO 3308:2000. The pressure drop (PD in Table 2) was measured in accordance with the standard ISO 6565: 2002. The nicotine content in the smoke was measured in accordance with the standard ISO 10315: 2000. The smoking results are given in Table 2 below.

TABLE-US-00002 TABLE 2 Commercial Filter Filter Filter Filter Filter cellulose comprising comprising comprising comprising made from acetate the substrate the substrate the substrate the substrate crimped filter of example 1-1 of example 1-2 of example 1-3 of example 1-4 CF36 paper Number of cigarettes smoked 30 PD of the cigarettes [mmWC] 104 1 100 1 95 1 106 1 90 1 100 1 Nicotine [mg/cigarette] 0.85 0.04 0.80 0.10 0.79 0.01 0.71 0.04 0.87 0.05 0.5 0.19

[0111] Table 2 demonstrates that, with an equivalent pressure drop, the cigarettes with filters according to the invention and the cigarettes comprising a commercial cellulose acetate filter have a nicotine content in the smoke which is of the same order of magnitude, whereas the cigarettes comprising a filter made from crimped paper have a much lower nicotine content in the smoke.

[0112] This example 3 thus demonstrates that the user experience provided by the cigarettes comprising the filters according to the invention is as satisfactory as that provided by cigarettes comprising a commercial cellulose acetate filter.

Example 4: Dispersion of the Filters in Water at Ambient Temperature

[0113] The filters comprising the substrates of example 1 without plug wrap paper, a commercial cellulose acetate filter without plug wrap paper and a paper filter without plug wrap paper were independently placed in 100 ml of tap water at 22 C. and stirred manually at 60 rpm for 30 sec every 4 hours to verify the dispersion thereof in the water. The time required for the fibers to detach from one another was noted. This time is indicated in table 3.

TABLE-US-00003 TABLE 3 Commercial Filter Filter Filter Filter Filter Filter cellulose comprising comprising comprising comprising comprising made from acetate the substrate the substrate the substrate the substrate the substrate crimped filter of example 1-1 of example 1-2 of example 1-3 of example 1-4 of example 1-5 CF36 paper Time required for the >24 h 20 sec 20 sec 20 sec >24 h 20 sec 8 h filter to disperse

[0114] The fibers of the filters from examples 1.1, 1.2, 1.3 and 1.5 come apart after 20 sec. The wood fibers of the filter made from crimped paper start to come apart from each other after 8 h. The paper filter is therefore less dispersible in water than the filter comprising the substrates of examples 1.1, 1.2, 1.3 and 1.5. After 24 h, the cellulose acetate filter and the filter of the invention of example 1.4 were unchanged. The cellulose acetate filter and the filter of example 1.4 do not disperse in the water.