Plasma treatment of filtration media for smoking articles

Abstract

A smoking article includes smokable material, a filter downstream of the smokable material, and a breakable capsule (80). The filter is plasma treated or has an increased surface energy relative to standard filter material. The breakable capsule (80) includes a core surrounded by a frangible shell. The core contains a liquid composition comprising a sensory-enhancing agent. The breakable capsule is positioned to cause the liquid composition to contact the filter material (32) when the shell is ruptured.

Claims

1. A smoking article comprising: smokable material; a filter downstream of the smokable material, the filter comprising plasma-treated filter material; and a breakable capsule comprising a core surrounded by a frangible shell, wherein the core comprises a liquid composition comprising a sensory-enhancing agent, wherein the breakable capsule is positioned to cause the liquid composition to contact the filter material when the shell is ruptured, and wherein distribution of the sensory-enhancing agent in the filter material is increased by at least 10% relative to filter material that is not plasma treated.

2. The smoking article of claim 1, wherein the plasma-treated filter material has a surface energy at least about 20% greater than untreated filter material.

3. The smoking article of claim 1, wherein the liquid composition comprises one or more lipids.

4. The smoking article of claim 1, wherein the filter material is treated with plasma by radio frequency discharge at a discharge dosage of at least 30 W/min/m.sup.2.

5. The smoking article of claim 1, wherein the distribution of the liquid composition in the filter material is increased at least 10% relative to untreated filter material when the shell is ruptured.

6. The smoking article of claim 1, wherein when the smoking article is subjected to ISO 3308 (2102) smoking procedure a cumulative amount of the sensory enhancing agent delivered in smoke within two minutes of breaking the capsule is at least 10% more than a cumulative amount of a sensory enhancing agent of a substantially similar smoking article having untreated filter material.

7. The smoking article of claim 1, wherein when the smoking article is subjected to ISO 3308 (2102) smoking procedure a cumulative amount of the sensory enhancing agent delivered in smoke within two minutes of breaking the capsule is at least 20% more than a cumulative amount of a sensory enhancing agent of a substantially similar smoking article having untreated filter material.

8. The smoking article of claim 1, wherein the filter material comprises cellulose acetate.

9. The smoking article of claim 8, wherein the plasma-treated filter material comprising cellulose acetate has a surface energy of 50 mN/m or greater.

10. The smoking article of claim 8, wherein the plasma-treated filter material comprising cellulose acetate comprises fibers having a thickness in a range from 1.5 to 8.0 denier per filament.

11. The smoking article of claim 1, wherein the filter material comprises polylactic acid.

12. The smoking article of claim 1, wherein the smokable material comprises tobacco.

Description

(1) Referring now to the drawings, in which some aspects of the present invention are illustrated. It will be understood that other aspects not depicted in the drawings fall within the scope and spirit of the present invention. The drawings are schematic drawings and are not necessarily to scale. Like numbers used in the figures refer to like components, steps and the like. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labelled with the same number. In addition, the use of different numbers to refer to components in different figures is not intended to indicate that the different numbered components cannot be the same or similar to other numbered components.

(2) FIG. 1 is a schematic diagram depicting plasma treatment of filter material.

(3) FIG. 2 is a schematic perspective view of a partially unrolled cigarette.

(4) FIGS. 3-4 are schematic longitudinal sectional views of embodiments of mouthpieces for smoking articles that include treated filter material and a breakable capsule.

(5) FIGS. 5A and 5B are photographs of untreated and plasma-treated filter material after contact with an oily composition.

(6) Referring now to FIG. 1, a plasma generator 100 can be used to treat filter material 32 with plasma 110 to increase the effective surface area and wettability of the filter material. In the depicted embodiment, the filter material 32 is moved in the direction indicated by the arrow such that untreated filter material 32 is passed under the plasma discharge 110 resulting in treated filter material 32. The filter material may be in the form of a web of material or, preferably, a band of fiber tow. In embodiments as depicted, the filter material can be treated in a continuous online process. One surface of the filter material can be plasma treated as shown. The opposing major surface of the web or tow band can also be treated.

(7) Referring now to FIG. 2, a schematic perspective view of an embodiment of a partially unrolled smoking article 10, in this case a cigarette, is depicted. The smoking article 10 includes a rod of smokable material 20, such as a tobacco rod, and a mouthpiece 30 downstream of the smokable material. The depicted smoking article 10 includes plug wrap 60, cigarette paper 40, and tipping paper 50. In the depicted embodiment, the plug wrap 60 circumscribes at portion of plasma treated filter material 32′. The cigarette paper 40 circumscribes at least a portion of the rod 20. Tipping paper 50 or other suitable wrapper circumscribes the plug wrap 60 and a portion of the cigarette paper 40 as is generally known in the art. The mouthpiece 30 includes a breakable capsule (not shown in FIG. 2), which may be oriented as depicted in, for example, FIGS. 3-4.

(8) Referring now to FIG. 3, the depicted mouthpiece 30 includes plug wrap 60 that circumscribes treated filter material 32, which surrounds breakable capsule 80.

(9) Referring now to FIG. 4, the depicted mouth piece includes a plug wrap 60 that circumscribes treated filter segments 32′, which are oriented in a plug-space-plug configuration. Breakable capsule 80 is disposed in space 33.

(10) An example of the enhanced uptake of a composition that can carry flavour or fragrance by a plasma-treated filter material is set out below.

(11) Two types of regular cigarette filters, named 1802 and 0540 are used in the experiment. The filters having the same circumference (24.3 mm) and length (108 mm) were cut longitudinally through the tipping paper and plug wrap once to reveal the filter material. The material used in the 0540 filter contains cellulose acetate tow at denier filament and total denier of 2.7Y35,000. The filter material used in the 1802 filter contains polylactic acid tow at denier filament and total denier of 3.2Y50,000. Both sets of filaments have a Y-shaped cross-section. The cut filters were exposed to plasma in a chamber for surface activation made by Plasma Etch Inc. (Nevada, USA). The settings of the plasma treatment were: low pressure at 200 mbar under argon gas, power setting at 50 W, frequency at 13.56 MHz, and 2 minutes treatment.

(12) The surface properties of the plasma-treated filter material was assessed by the distribution of a liquid composition comprising 30 ml of coconut oil and 20 microgram of the food colouring E132, also known as indigo carmine. Sensory enhancing agents such as fragrance and flavours are commonly dissolved in and/or carried by an oily liquid composition, such as coconut oil. The same volume of 20 microlitres of the liquid composition is placed onto the exposed filtration material. An increase in the area of blue staining of the filter by the composition is an indication of an improved penetration and absorption of the composition. Taken about 5 seconds after the drop is placed onto the filter, the photograph of FIG. 5A shows the difference between an untreated reference 1802 filter and an argon plasma-treated 1802 filter when the oily composition contacted the filter material; the photograph of FIG. 5B shows the difference between an untreated reference 0504 filter and an argon plasma-treated 0504 filter when the oily composition contacted the filter material. In both types of filtration material, the staining is about 20% to 40% more widespread in plasma-treated samples than the reference samples. The conclusion is that plasma treatment of filter material made with typical substances, such as cellulose acetate or polylactic acid, can increase the distribution of sensory enhancing agent in the filter. For example, the penetration, absorption, or penetration and absorption of the sensory enhancing agent in the filter may be increased.

(13) Accordingly, it is shown that the distribution of a sensory enhancing agent in an oily liquid composition by a cigarette filter treated by plasma under argon, can be increased relative to an untreated filter by at least 10%, at least 20%, at least 30% or at least 40% or 10% to 20%, 10% to 30%, 20% to 40%, 30% to 40% as measured by the area of penetration and absorption of the agent in the filter in a method similar to the above-described example.

(14) Thus, methods, systems, devices, compounds and compositions for PLASMA TREATMENT OF FILTRATION MEDIA FOR SMOKING ARTICLES are described. Various modifications and variations of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are apparent to those skilled in cigarette manufacturing or related fields are intended to be within the scope of the following claims.