COATED PLUG WRAP TO ENHANCE FILTER HARDNESS

Abstract

A method for enhancing hardness of a filter for a smoking article includes disposing a plug wrap about filter material; and applying a hardness-enhancing coating composition to the plug wrap after the plug wrap has been disposed about the filter material to enhance the hardness of the filter.

Claims

1-8. (canceled)

9. A method for enhancing hardness of a filter for a smoking article comprising: disposing a plug wrap about filter material; and applying a hardness-enhancing coating composition to the plug wrap after the plug wrap has been disposed about the filter material to enhance the hardness of the filter.

10. A method according to claim 9, wherein the coating composition comprises polyvinyl alcohol having a solid content from 10% to 70%.

11. A method according to claim 9, wherein the coating composition consists essentially of polyvinyl alcohol.

12. A method according to claim 9, wherein the coating composition is applied to the plug wrap at a rate from 20 meters/min to 50 meters/min.

13. A method according to claim 9, further comprising curing of the coated filter to remove solvent from the applied coating composition.

14. A method according to claim 13, wherein the drying occurs at ambient temperature.

15. A method according to claim 13, wherein the coating composition is applied to the plug wrap in an amount sufficient to produce a coating layer having a thickness is a range from 2 micrometers to 200 micrometers after the filter is dried.

16. A method according to claim 10, wherein the polyvinyl alcohol has a molecular weight in a range from 40 to 125,000 grams/mol.

17. A method according to claim 9, wherein the filter has a longitudinal hardness that is at least 2N greater than a filter having a plug wrap to which the coating is not applied.

18. A method according to claim 9, wherein the filter has a radial hardness that is at least 2% greater than a filter having a plug wrap to which the coating is not applied.

Description

[0040] 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 schematic drawings 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.

[0041] FIG. 1 is a flow diagram of an embodiment of a method for manufacturing a smoking article having a filter with enhanced hardness.

[0042] FIG. 2 is a schematic sectional view of an embodiment of a filter having a coated plug wrap.

[0043] FIG. 3 is a schematic perspective view of an embodiment of a partially unrolled cigarette having a filter with a coated plug wrap.

[0044] Referring now to FIG. 1, an embodiment of a method for manufacturing a smoking article having a filter with enhanced hardness is depicted. The method includes wrapping a plug wrap around filter material to form a filter (100). The filter material may be formed on conventional filter-forming equipment and manufacturing lines. For example, the filter material may be formed from cellulose acetate tow using standard equipment. Once formed, the plug wrap may be wrapped around to the filter material to form the filter. A filter precursor consisting of a multiple of filter units may be formed and then cut to appropriate lengths to form the filter. Once the filter is formed, the plug wrap is coated (110) with a hardness-enhancing composition and dried to form a coating that enhances the hardness, preferably the radial hardness and the longitudinal hardness, of the filter. Preferably, the plug wrap is coated at high speeds on the manufacturing line. The filter with the coated plug wrap may then be incorporated into a smoking article (120) in a manner as generally known in the art.

[0045] Referring now to FIG. 2, a schematic sectional view of an embodiment of a filter 30 is shown. The filter 30 includes filter material 32 forming a core and a plug wrap 62 circumscribing the filter material 32. An outer surface (the surface facing away from the filter material) of the plug wrap 62 is coated with a hardness-enhancing coating 65.

[0046] Referring now to FIG. 3, 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 is depicted as partially unrolled merely to illustrate representative components of the article. The smoking article 10 includes a rod of smokable material 20, such as a tobacco rod, and a filter 30 downstream of the smokable material 20. The filter 30 and the rod 20 are coaxially aligned with the longitudinal axis of the smoking article 10, which axis is depicted by line A-A. The depicted smoking article 10 includes a coated plug wrap 60, cigarette paper 40, and tipping paper 50. The cigarette paper 40 circumscribes at least a portion of the rod 20. Tipping paper 50 or other suitable wrapper circumscribes the coated plug wrap 60 and a portion of the cigarette paper 40 as is generally known in the art. The filter 30 includes the coated plug wrap 60 and filter material 32. The plug wrap includes an inner surface 62 that faces the longitudinal axis A-A of the smoking article 10 and that may contact the filter material 32. The coated plug wrap includes an opposing outer surface (not shown in FIG. 3) that faces away from the longitudinal axis A-A of the smoking article 10. The hardness-enhancing coating (not shown in FIG. 3) is on the outer surface of the plug wrap 60 (see, for example, FIG. 2).

[0047] The exemplary embodiments described above are not limiting. Other embodiments consistent with the exemplary embodiments described above will be apparent to those skilled in the art.

[0048] All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein.

[0049] As used herein, the singular forms “a”, “an”, and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise.

[0050] As used herein, “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. The term “and/or” means one or all of the listed elements or a combination of any two or more of the listed elements.

[0051] As used herein, “have”, “having”, “include”, “including”, “comprise”, “comprising” or the like are used in their open ended sense, and generally mean “including, but not limited to”. It will be understood that “consisting essentially of”, “consisting of”, and the like are subsumed in “comprising,” and the like.

[0052] The words “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure, including the claims.

[0053] Thus, methods, systems, apparatuses, assemblies and articles for coated plug wraps for enhancing filter hardness 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 the mechanical arts, electrical arts, and aerosol generating article manufacturing or related fields are intended to be within the scope of the following claims.