TOBACCO SMOKE FILTER AND METHOD OF PRODUCTION

Abstract

A method of producing a flavoured tobacco smoke filter or filter element comprising a self-sustaining longitudinally extending cylindrical core comprising fibres or filaments of tobacco smoke filtering material which are bonded at their points of contact; the method comprising a step of applying a flavouring agent to a longitudinally advancing flow of filters and/or filter elements and/or multiple filter rods. Filters and filter elements are also provided.

Claims

1. A method of producing a flavoured tobacco smoke filter or filter element comprising a plurality of individual tobacco smoke filters or filter elements abutted end to end, each filter or filter element including a self-sustaining longitudinally extending cylindrical core comprising fibres or filaments of tobacco smoke filtering material bonded at their points of contact and a flavouring agent; and a wrapper around the plurality of individual tobacco smoke filters or filter elements; the method comprising a step of applying the flavouring agent to a longitudinally advancing flow of pre-formed multiple filter rods immediately prior to wrapping.

2. The method according to claim 1 wherein the wrapper extends longitudinally at each end beyond the abutted plurality of individual tobacco smoke filters or filter elements and is sealed or partially sealed.

3. The method according to claim 2 wherein the flavouring agent is applied in amount of between 0.1 and 8 milligrams per filter or filter element.

4. The method according to claim 3 wherein the tobacco smoke filtering material is cellulose acetate tow.

5. The method according to claim 4 wherein the wrapper is transparent.

6. The method according to claim 3 wherein the wrapper is transparent.

7. The method according to claim 2 wherein the tobacco smoke filtering material is cellulose acetate tow.

8. The method according to claim 7 wherein the wrapper is transparent.

9. The method according to claim 2 wherein the wrapper is transparent.

10. The method according to claim 1 wherein the flavouring agent is applied in amount of between 0.1 and 8 milligrams per filter or filter element.

11. The method according to claim 10 wherein the tobacco smoke filtering material is cellulose acetate tow.

12. The method according to claim 11 wherein the wrapper is transparent.

13. The method according to claim 10 wherein the wrapper is transparent.

14. The method according to claim 1 wherein the tobacco smoke filtering material is cellulose acetate tow.

15. The method according to claim 14 wherein the wrapper is transparent.

16. The method according to claim 1 wherein the wrapper is transparent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present invention will now be illustrated with reference to the following Examples and the attached drawings in which FIG. 1 schematically illustrates a product rod of filters according to an embodiment of the invention; FIG. 2 schematically illustrates a product rod of filters according to a further embodiment of the invention; FIG. 3 schematically illustrates a method and apparatus according to further embodiments of the invention which may be used to manufacture the product of e.g. FIG. 1 or 2; FIG. 4 illustrates a product rod of filters according to a further embodiment of the invention; and FIG. 5 is a schematic side elevation view of an example of an apparatus used for forming the filter of FIG. 4.

DETAILED DESCRIPTION

[0057] FIG. 1 shows a flavoured NWA “Pop-a-tip” product 1 according to one embodiment of the invention.

[0058] The product 1 comprises a plurality of six tobacco smoke filters 3 each of around 17.5 mm circumference and length 14 mm abutted end to end. Each filter 3 includes a self-sustaining substantially cylindrical core formed from a plurality of longitudinally extending substantially continuous filaments of crimped cellulose acetate tow which are bonded at their points of contact (i.e. each filter 3 is a NWA filter), to which menthol flavouring agent has been applied in an amount of 6 mg per filter (see method below). The product 1 also includes a wrapper 5 comprising a transparent film made of BOPP or cellophane which surrounds the filters 3 thereby forming a wrapped cylinder of six filter elements.

[0059] In use the smoker takes product 1 and pushes or pops a filter 3 individually out of the transparent wrap; the filter is then used when rolling a RYO cigarette. It was expected that mentholated “Pop-a-Tip” products according to the invention would be more difficult to ‘pop’ than the equivalent non-mentholated tips because the presence of tiny menthol crystals on the surface of the filter (after menthol application) would increase frictional forces within the transparent wrap. Surprisingly, the applicants have found that there is no discernable difference between the ‘ease of popping’ of the product of the invention and the prior art non-mentholated “Pop-a-Tip” products.

[0060] FIG. 2 shows a flavoured NWA “Pop-a-tip” product 11 according to a further embodiment of the invention. The product 11 comprises a plurality of six tobacco smoke filters 13 each of around 17.5 mm circumference and length 14 mm abutted end to end. Each filter 13 includes a self-sustaining substantially cylindrical core formed from a plurality of longitudinally extending substantially continuous filaments of crimped cellulose acetate tow which are bonded at their points of contact (i.e. each filter 13 is a NWA filter), to which menthol flavouring agent has been applied in an amount of 4 mg per filter (see method below). The product 13 also includes a wrapper 15 comprising a transparent film made of BOPP or cellophane which surrounds the filters 13 thereby forming a wrapped cylinder of six filter elements 13. As can be seen in FIG. 2 the wrapper extends longitudinally at each end 17a, 17b of the cylinder beyond the abutted plurality of individual tobacco smoke filters or filter elements and is sealed (or partially sealed) by crimping. The crimping advantageously reduces loss of flavouring agent from the product wrapped filters or filter elements prior to use. The method of use of product 11 is similar to that of product 1; the user simply pushes or pops a filter 13 individually out of the transparent wrap. As will be understood, the first filter which is popped from the product may either be popped through the crimped end (17a or 17b) of the product, or the crimped end may be torn or cut away prior to popping the filter out.

[0061] It will be appreciated that in further embodiments of the invention, the filters 3, 13 in the above examples could instead be replaced with filters comprising a self-sustaining (longitudinally extending) cylindrical core formed from a plurality of randomly oriented individual or staple fibres of tobacco smoke filtering material (e.g. cellulose acetate tow) which are bonded at their points of contact, for example as disclosed in U.S. Pat. No. 3,552,400. The flavouring agent would be applied in a similar way (see below).

[0062] FIG. 3 shows a method and apparatus according to a further embodiment of the invention which may be used to manufacture the product of FIG. 1.

[0063] As can be seen in FIG. 3 a flow of pre-formed filters 103 and pre-formed dual filter rods 103a is longitudinally advanced in the direction of arrow 104 into a garniture unit 106.

[0064] The pre-formed filters 103 are each of around 17.5 mm circumference and length 14 mm. Each filter 103 includes a self-sustaining substantially cylindrical core formed from a plurality of longitudinally extending substantially continuous filaments of crimped cellulose acetate tow which are bonded at their points of contact. The pre-formed dual filter rods 103a are each of around 17.5 mm circumference and length 28 mm. Each rod 103a includes a self-sustaining substantially cylindrical core formed from a plurality of longitudinally extending substantially continuous filaments of crimped cellulose acetate tow which are bonded at their points of contact. The filters 103 are NWA filters and may, as well as dual rods 103 a, be manufactured by a process similar to that described in UK Patent No. 1169932 (U.S. Pat. No. 3,455,766), in which filaments of cellulose acetate tow to which a plasticiser has been applied are fed into a forming station where a belt is folded around the tow until the longitudinal edges of the belt are juxtaposed and the tow is confined within the belt; the tow is thus formed into a longitudinally extending cylinder by the belt. The belt is then moved to a heat treating station where a heating fluid (e.g. steam) is passed through the belt into contact with the tow to activate the plasticizer. The belt and tow therewithin are then moved through a cooling station where cool air or other fluid is passed through the belt into contact with the tow to deactivate the plasticizer, if necessary, and dry the tow by removal of condensed steam, whereby the tow is made rigid to form a continuous self sustaining and stable longitudinally extending rod. The continuous self sustaining and stable longitudinally extending rod is cut into base rods of filters for subsequent use also by methods well known in the art.

[0065] As indicated above, conventional Pop-a-Tip manufacture takes place on a dual rod filter making machine. These machines are well known in the art and normally used for combining two different types of base rod, which are held in two different hoppers on the machine. For Pop-a-Tip manufacture the two hoppers are filled with the same base rod type and these base rods are cut down (to provide the required tip length), aligned in an end-to-end relationship, wrapped in transparent film and cut to the final required Pop-a-Tip length. In the process of the present invention the two hoppers of the dual rod filter making machine (not shown) are also filled with base rods of filters 103 manufactured as set out above. One hopper is used to cut down the base rods to individual filters 103 of the required tip length (14 mm) and the other hopper is used to cut down the base rods to dual filter rods 103a of the required tip length (28 mm) and the dual rod machine is then set to arrange and align the filters 103 and dual filter rods 103a in an end-to-end relationship such that each dual filter rod 103 is separated form the next rod 103a by four individual filters 103 to provide the flow of pre-formed filters 103 and multiple (dual) filter rods 103a. As can be seen In FIG. 3 the filters 103 are aligned and abutted end to end (i.e. there are no spaces between individual filters 103 or filters 103 and filter rods 103a) prior to longitudinal advancement in the direction of arrow 104 into the garniture unit 106.

[0066] The garniture unit 106 includes a compression shoe 108 through which the aligned and abutted filters 103 and dual filter rods 103a are passed prior to wrapping in the garniture. Compression shoes are known in the art for control of the final circumference of the finished rod, but novel compression shoe 108 includes flavor applicator inlet 110 and outlet 112 (in other examples the inlet may feed more than one outlet). A flavouring agent in the form of a menthol solution is pumped under pressure through compression shoe 108 via inlet 110 and outlet 112 to apply menthol to the aligned and abutted filters 103 and filter rods 103a as they are advanced longitudinally through the shoe 108 and garniture 106.

[0067] The flow of flavouring agent is controlled by methods known in the art such that the desired flavor loading (e.g. 6 mg menthol per filter 103, 12 mg per filter rod 103a) is achieved. The applicants have surprisingly found that flavour can be applied to the filters immediately prior to wrapping in the (e.g. transparent) film thereby avoiding problems associated with removal of volatile flavouring agents during manufacture of the filters.

[0068] A transparent cellophane wrapper 105 is applied to the continuously advancing flow of filters or filter elements to which the flavouring agent has been applied in the garniture 106 in the conventional manner, to thereby form a continuous wrapped rod 111 comprising groups of four filters 103 bearing flavouring agent separated by dual flavour agent bearing filter rods 103a. The continuous wrapped rod 111 is then cut in register with a position half way along each dual filter rod 103a (see arrow 222) by methods known in the art to provide products 101 each comprising a plurality of filters 103 in a common cellophane wrapper, for example such as those illustrated in FIG. 1.

[0069] It will be appreciated that a product as shown in FIG. 2 may be made by modification of the method of FIG. 3. The settings of the dual rod maker are adjusted to provide a longitudinally advancing flow comprising pluralities of abutted filters 103 with each plurality of filters longitudinally spaced from the next along the flow. The wrapper is then applied to the continuously advancing flow (after menthol application) to form a continuous wrapped rod comprising longitudinally spaced pluralities of abutted filters bearing flavouring agent. The continuous wrapped rod is then cut in register with the spaces between the pluralities of abutted filter or filter elements and the cut ends of the wrapper crimped and/or otherwise at least partially sealed.

[0070] FIG. 4 shows a flavoured NWA Flavour Thread “Pop-a-tip” product 301 according to one embodiment of the invention.

[0071] The product 301 comprises a plurality of six tobacco smoke filters 303 each of around 17.5 mm circumference and length 14 mm abutted end to end. Each filter 303 includes a self-sustaining substantially cylindrical core formed from a plurality of longitudinally extending substantially continuous filaments of crimped cellulose acetate tow which are bonded at their points of contact, and a continuous component in the form of a green cotton thread 307 which extends longitudinally of the cylindrical core (i.e. each filter 303 is a NWA filter which includes a thread). Menthol flavouring agent has been applied in an amount of 6 mg per filter to each filter 303, by the method described above with reference to FIG. 3. The product 301 also includes a wrapper 305 comprising a transparent film made of BOPP or cellophane which surrounds the filters 303 thereby forming a wrapped cylinder of six filter elements.

[0072] In use the smoker takes product 301 and pushes or pops a filter 303 individually out of the transparent wrap; the filter is then used when rolling a RYO cigarette. Surprisingly, as with the embodiment of FIGS. 1 and 2, the applicants have found that there is no discernable difference between the ‘ease of popping’ of the product of the invention and the prior art non-mentholated “Pop-a-Tip” products. Further, it will be appreciated that the green thread 307 visible at each end of filter 303 provides a distinctive end appearance which is useful as e.g. an indicator that the filter tip is flavoured and/or for anti-counterfeiting measures.

[0073] FIG. 5 shows a schematic side elevation view of an apparatus for forming filters 301 of the invention according to FIG. 4. The apparatus is well known in the art. A band of cellulose acetate tow 510 to which plasticiser has been applied (application of plasticiser not shown) is drawn over an upwardly convex bowed bar 516 upstream of a ring or funnel 515. The bar 516 shapes the tow 510 reaching funnel 515 into a downwardly concave arch into which is positioned thread guide mandrel 548. The tow passes through funnel 515, which has an internal wall converging downstream, and is further gathered and condensed into rod form as it enters and passes through a rod forming station 520. A continuous component in the form of (optionally dyed e.g. green) cotton thread 522 is drawn continuously from a reel 524 (optionally, if flavour is desired, through a flavouring agent, e.g. menthol, applicator 526). The thread 522 is drawn from reel 524, optionally flavoured, and led directly into engagement with the tow by means of the thread guide mandrel 548 at a region just upstream of funnel or ring 515, and travels with the tow to and through the rod forming station 520, to become incorporated in and extend the length of the rod produced. On start up of the apparatus, the tow is threaded through the machine into the rod forming station 520, and the free end of thread 522 is stuck to the tow upstream of funnel or ring 515; once the apparatus has been started, the advancing tow continuously entrains the thread 522 and draws it continuously from reel 524 via guide mandrel 548. The cellulose acetate tow to which a plasticiser has been applied is fed, together with the entrained thread 522, into the rod forming station 520 where a belt is folded around the tow until the longitudinal edges of the belt are juxtaposed and the tow is confined within the belt; the tow is thus formed by the belt into a longitudinally extending cylinder enclosing the thread 522. The belt is then moved to a heat treating station where a heating fluid (e.g. steam) is passed through the belt into contact with the tow to activate the plasticizer. The belt and tow therewithin are then moved through a cooling station where cool air or other fluid is passed through the belt into contact with the tow to deactivate the plasticizer, if necessary, and dry the tow by removal of condensed steam, whereby the tow is made rigid to form a continuous self sustaining and stable longitudinally extending rod 536. The continuously produced rod 536 passes to a cutter 538 which severs the rod 536 into individual lengths 540 each of which includes a continuous self-sustaining longitudinally extending cylindrical core comprising a plurality of longitudinally extending substantially continuous filaments of tobacco smoke filtering material (the cellulose acetate) which are bonded at their points of contact surrounding a continuous component (the thread) extending longitudinally of the core. The lengths 540 may be single filter or filter elements, but, more usually, will be multiple double or higher multiple filter rods (usually quadruple or sextuple) lengths for subsequent use, as is well known. The above apparatus is well known and similar to that discussed in, for example, U.S. Pat. No. 4,281,671.

[0074] It will be appreciated that the lengths 540 may be used to make a product as shown in FIG. 1, using a modification of the method of FIG. 3. The two hoppers of a dual rod filter making machine (not shown) are filled with base rods of filters 303 manufactured as set out above. One hopper is used to cut down the base rods to individual filters 303 of the required tip length (14 mm) and the other hopper is used to cut down the base rods to dual filter rods 303a of the required tip length (28 mm) and the dual rod machine is then set to arrange and align the filters 303 and dual filter rods 303a in an end-to-end relationship such that each dual filter rod 303 is separated form the next rod 303a by four individual filters 303 to provide the flow of pre-formed filters 303 and multiple (dual) filter rods 303a. The filters 303 are aligned and abutted end to end (i.e. there are no spaces between individual filters 303 or filters 303 and filter rods 303a) prior to longitudinal advancement into a garniture unit, for example a garniture unit as shown in FIG. 3.

[0075] The garniture unit 106 includes a compression shoe 108 through which the aligned and abutted filters 303 and dual filter rods 303a are passed prior to wrapping in the garniture. A flavouring agent in the form of a menthol solution is pumped under pressure through compression shoe (as in FIG. 3) to apply menthol to the aligned and abutted filters 303 and filter rods 303a as they are advanced longitudinally through the shoe and garniture. A transparent cellophane wrapper is applied to the continuously advancing flow of filters or filter elements to which the flavouring agent has been applied in the garniture in the conventional manner, to thereby form a continuous wrapped rod comprising groups of four filters 303 bearing flavouring agent separated by dual flavour agent bearing filter rods 303a. The continuous wrapped rod is then cut in register with a position half way along each dual filter rod 303a by methods known in the art to provide products 301 each comprising a plurality of filters 303 in a common cellophane wrapper, for example such as those illustrated in FIG. 4.

[0076] It will also be appreciated that filters and filter elements according to some embodiments of the invention may be made by forming filaments of cellulose tow (to which plasticiser has been applied) around a continuous element bearing a flavouring agent; and then using a heating fluid (and optionally cooling) to activate the plasticiser, whereby the filtering rod is made rigid and stable. In other words, filters and filter elements according to some embodiments of the invention may be made using the apparatus of FIG. 5, wherein the flavouring agent is applied only using the flavouring agent, e.g. menthol, applicator 526. It will be appreciated that this method of manufacture does not require application of flavouring agent to the filtering rod after it has been made rigid and stable, because the flavouring agent will be dispersed over the continuous element and the remainder of the filter element. However, this method, although simpler, may not be preferred where high loadings of flavouring agent are required, because flavouring agent is lost during manufacture (due to its inherent volatility).