PAPER WRAPPER FOR AN ELECTRICALLY HEATED AEROSOL-GENERATING ARTICLE

Abstract

An electrically heatable aerosol-generating article is provided, including an aerosol-generating substrate including at least one aerosol former; a mouthpiece; and a paper wrapper circumscribing at least a portion of the aerosol-generating substrate, the paper wrapper having a wet tensile strength of at least 5 Newtons per 15 millimeters when measured in accordance with the Wet Tensile Strength Test.

Claims

1. An electrically heatable aerosol-generating article, comprising: an aerosol-generating substrate comprising at least one aerosol former; a mouthpiece; and a paper wrapper circumscribing at least a portion of the aerosol-generating substrate, the paper wrapper having a wet tensile strength of at least 5 Newtons per 15 millimetres when measured in accordance with the Wet Tensile Strength Test.

2. The electrically heatable aerosol-generating article according to claim 1, wherein the paper wrapper has a dry tensile strength of at least 10 Newtons per 15 millimetres when measured in accordance with the Dry Tensile Strength Test.

3. The electrically heatable aerosol-generating article according to claim 1, wherein the at least one aerosol former comprises at least one polyol.

4. The electrically heatable aerosol-generating article according to claim 2, wherein the at least one aerosol former comprises at least one polyol.

5. The electrically heatable aerosol-generating article according to claim 3, wherein the at least one polyol comprises at least one of sorbitol, glycerol, propylene glycol, and triethylene glycol.

6. The electrically heatable aerosol-generating article according to claim 4, wherein the at least one polyol comprises at least one of sorbitol, glycerol, propylene glycol, and triethylene glycol.

7. The electrically heatable aerosol-generating article according to claim 1, wherein the aerosol-generating substrate further comprises water in an amount of between 10 percent and 20 percent by weight of the aerosol-generating substrate.

8. The electrically heatable aerosol-generating article according to claim 2, wherein the aerosol-generating substrate further comprises water in an amount of between 10 percent and 20 percent by weight of the aerosol-generating substrate.

9. The electrically heatable aerosol-generating article according to claim 3, wherein the aerosol-generating substrate further comprises water in an amount of between 10 percent and 20 percent by weight of the aerosol-generating substrate.

10. The electrically heatable aerosol-generating article according to claim 4, wherein the aerosol-generating substrate further comprises water in an amount of between 10 percent and 20 percent by weight of the aerosol-generating substrate.

11. The electrically heatable aerosol-generating article according to claim 5, wherein the aerosol-generating substrate further comprises water in an amount of between 10 percent and 20 percent by weight of the aerosol-generating substrate.

12. The electrically heatable aerosol-generating article according to claim 6, wherein the aerosol-generating substrate further comprises water in an amount of between 10 percent and 20 percent by weight of the aerosol-generating substrate.

Description

[0056] FIG. 1 illustrates the measuring principle and the relevant dimensions of the test specimen before the test and when stretched during the test.

[0057] FIG. 2 illustrates a typical force/elongation curve obtained for a single test specimen and the relevant formulae for calculating the tensile strength and stretch at break.

[0058] FIGS. 3A-3B illustrate results of the Dry Tensile Strength Test for standard paper used to construct the reference articles and for RD paper used to construct the test articles, according to an embodiment.

[0059] FIGS. 4A-4B illustrate results of the Wet Tensile Strength Test for standard paper and for RD paper, measured for the addition of 2 μL of water, according to an embodiment.

[0060] FIGS. 5A-5B illustrate results of the Wet Tensile Strength Test for standard paper and for RD paper, measured for the addition of 2 μL of glycerine, according to an embodiment.

[0061] FIGS. 6A-6B illustrate results of the Wet Tensile Strength Test for standard paper and for RD paper, measured for the addition of 2 μL of a 1:1 mixture of water and glycerine, according to an embodiment.

[0062] FIG. 7 illustrates results of the smoking test for reference articles constructed with standard paper and for test articles constructed with the RD paper, according to an embodiment.

WET TENSILE STRENGTH TEST

[0063] The Wet Tensile Strength Test measures the tensile strength of a paper sample conditioned under wet conditions. The test is identical to the Dry Tensile Strength Test, except for the addition of 2 micro litres of liquid to the test sample after conditioning for at least 24 hours at 22±2 degrees Celsius and 60±5% relative humidity and after cutting the test sample to size. The 2 micro litres of liquid is applied with a syringe to the centre of the test sample, immediately prior to the pulling step of the test procedure.

BREAKAGE TEST

[0064] The breakage test subjects an aerosol-generating article comprising a paper outer wrapper to a full heating cycle in the appropriate aerosol-generating device, without puffing, followed by extraction of the aerosol-generating article from the aerosol-generating device. The test is repeated for a number of identical aerosol-generating articles and the percentage of aerosol-generating articles exhibiting a breakage of the paper outer wrapper is determined by a visual inspection.

SMOKING TEST

[0065] To determine the composition of the aerosol generated by an aerosol-generating article the aerosol-generating article is subjected to a heating cycle in the appropriate aerosol-generating device under the Health Canada smoking regime (12 puffs with a puff volume of 55 millilitres, puff duration of 2 seconds and a puff interval of 30 seconds).

EXAMPLE

[0066] A number of reference aerosol-generating articles were constructed using an outer wrapper formed from a conventional paper wrapper, and a number of test aerosol-generating articles were constructed. The test aerosol-generating articles were constructed identically to the reference aerosol-generating articles, except the outer wrapper was formed from a paper in accordance with the first aspect of the present invention. The paper used for the test aerosol-generating articles is available from Delfortgroup AG under product code CP.A646.

[0067] FIG. 1 illustrates the measuring principle and the relevant dimensions of the test specimen before the test and when stretched during the test. In FIG. 1, w indicates the width of the test specimen in mm; I.sub.o indicates the initial length between grips in mm; l indicates the length between grips during the stretch in mm; Δ.sub.l indicates the elongation during the stretch (*l=l−l.sub.o) in mm; and F indicates the force during the stretch in N.

[0068] FIG. 2 illustrates a typical force/elongation curve obtained for a single test specimen and the relevant formulae for calculating the tensile strength and stretch at break. In FIG. 2, the following definitions are for plug wrap paper, cigarette paper, banded cigarette paper, tipping paper, and pre-cut tipping paper: L indicates the load max in N; S indicates the tensile strength in N/mm; “S at break” indicates the tensile breaking strength in N/15mm; ε.sub.b indicates the stretch at break in %; F.sub.max indicates the maximum force during the stretch in N; w indicates the width of the test specimen in mm; l.sub.o indicates the initial length between grips in mm; Δ.sub.lb indicates the elongation at break in mm; the tensile breaking strength is given by

[00001]$S=\frac{F_{\max }}{w}\left[N\text{/}\mathrm{mm}\right];$

the stretch at break is given by

[00002]${\mathrm{.Math.}}_b\frac{\Delta l_b}{I_o}.Math.100\left[\%\right];$

and the force at break of pre-cut tipping paper is given by L=Load Max [N].

[0069] The conventional paper (standard paper) used to construct the reference articles and the test paper (RD paper) used to construct the test articles were both subjected to the Dry Tensile Strength Test and the results are recorded in FIGS. 3A-3B. The results show that the conventional paper and the test paper both exhibit substantially the same dry tensile strength, which advantageously permits the use of the test paper in the construction of aerosol-generating article without the need to substantially modify existing manufacturing machines and processes.

[0070] The conventional and test papers were also subjected to three separate Wet Tensile Strength Tests: addition of 2 micro litres of water (results recorded in FIGS. 4A-4B); addition of 2 micro litres of glycerine (results recorded in FIGS. 5A-5B); and addition of 2 micro litres of a 1:1 mixture of water and glycerine (results recorded in FIGS. 6A-6B). The Wet Tensile Strength Test results show that the test paper exhibited a significantly larger wet tensile strength when compared to the conventional paper. In the test in which a mixture of water and glycerine was added to the papers, which most closely resembles the moisture content of a typical aerosol-generating substrate in an electrically heated article, the test paper exhibited a wet tensile strength nearly 8 times larger than the wet tensile strength of the conventional paper.

[0071] The increased wet tensile strength of the test paper is also evident in the results of the breakage test, in which a number of each of the reference articles and the test articles was subjected to the Breakage Test. Specifically, the reference articles constructed with the conventional paper exhibited breakage in approximately 59 percent of the articles tested, whereas none of the test articles constructed with the test paper exhibited any breakage of the paper wrapper.

[0072] Finally, the reference articles constructed with the conventional paper and the test articles constructed with the test paper were both smoked according to the Smoking Test and the results recorded in FIG. 7. The results show that substituting the conventional paper with the test paper did not create any significant change in the composition of the aerosol delivered from the aerosol-generating article.