Abstract
There is provided a tobacco smoke filter (1) or filter element comprising: a rod (2) of a tobacco smoke filtering material; a continuous extruded element (7) extending longitudinally of the rod (2); and a flavouring agent.
Claims
1. A tobacco smoke filter or filter element comprising: a rod of a tobacco smoke filtering material; a continuous extruded element extending longitudinally of the rod; and a flavouring agent, wherein the continuous extruded element extending longitudinally of the rod further comprises a pigment of a contrasting colour to the tobacco smoke filtering material, wherein the continuous extruded element extending longitudinally of the rod is of diameter, or width at narrowest point, of from about 0.5 to about 10 mm, and the continuous extruded element extending longitudinally of the rod has a solid cross-section along a full length thereof and is visible at a mouth end of the filter or filter element.
Description
(1) The present invention will now be illustrated with reference to the attached drawings in which:
(2) FIG. 1 is a perspective, part cut away, view of a tobacco smoke filter according to an aspect of the invention;
(3) FIG. 2 is a schematic side elevation view of an example of an apparatus for forming the filter of FIG. 1; and
(4) FIG. 3 is a perspective, part cut away, view of a tobacco smoke filter according to another embodiment of the invention
(5) FIG. 1 is a perspective, part cut away, view of a filter 1. Filter 1 includes a substantially cylindrical rod 2 of tobacco smoke filtering material in the form of a cylindrical cellulose acetate plug of length 27 mm and circumference of around 25 mm. The substantially cylindrical rod 2 is made from cellulose acetate tow which has been gathered and condensed into rod form by methods which are well known in the art (see e.g. below). Filter 1 includes a continuous extruded element 7 extending longitudinally through rod 2, formed from extruded cellulose acetate. The continuous extruded element 7 also includes a green pigment, but it will be appreciated that other pigments (blue, red etc.) may be used, or the continuous extruded element 7 may be white. The continuous extruded element 7 is of solid, circular, cross-section, and extends through the body of the rod 2 from one end of the filter to the other, thus presenting a green circle at each end of rod 2, which contrasts with the white colour of the cellulose acetate tow which has been gathered and condensed into rod form. The continuous extruded element 7 has, applied thereon, menthol. The menthol may be applied e.g. by the methods discussed in U.S. Pat. No. 4,281,671. Methods of preparing extrusion grade cellulose acetate powder are known (e.g. see U.S. Pat. No. 4,228,246). Extrusion-grade cellulose ester pellets are commercially available from Rotuba Extruders of Linden, N.J. under the trade mark Naturacell. The extrusion-grade cellulose ester pellets are converted into an extruded element, and pigmented, by methods well known in the art. Filter 1 includes a paper wrapper 8 surrounding longitudinally extending core 2 which may be perforated (not shown) or air-permeable to provide a ventilated filter.
(6) It will be appreciated that the filter of FIG. 1 may be joined at its upstream end 9 to a wrapped tobacco rod (not shown) by means of, for example, a full tipping overwrap which surrounds and engages the full length of the filter 1 and the adjacent end only of the wrapped tobacco rod, to form a filter cigarette. The filter of FIG. 1 may also be attached to a tobacco rod to form a filter cigarette by other means known in the art, such as ring tipping.
(7) FIG. 2 shows a schematic side elevation view of an apparatus for forming filters of the invention, for example according to FIG. 1. The apparatus is well known in the art. A band of cellulose acetate tow 10 is drawn over an upwardly convex bowed bar 16 upstream of a ring or funnel 15. The bar 16 shapes the tow 10 reaching funnel 15 into a downwardly concave arch into which is positioned an extruded element guide mandrel 48. The tow passes through funnel 15, which has an internal wall converging downstream, and is further gathered and condensed into rod form as it enters and passes through the conventional rod making and wrapping garniture 20. A continuous extruded element 22 of (optionally pigmented e.g. green) extruded cellulose acetate is drawn continuously from a reel 24 (optionally, if flavour is desired, through a flavouring agent, e.g. menthol, applicator 26). Methods of preparing extrusion grade cellulose acetate powder are known (e.g. see U.S. Pat. No. 4,228,246). Extrusion-grade cellulose ester pellets are commercially available from Rotuba Extruders of Linden, N.J. under the trade mark Naturacell. The extrusion-grade cellulose ester pellets are converted into an extruded element, and e.g. pigmented, by methods well known in the art. The prepared extruded element is then stored on a reel (e.g. reel 24) for later use. The extruded element 22 is drawn from reel 24, optionally flavoured, and led directly into engagement with the tow by means of the extruded element guide mandrel 48 at a region just upstream of funnel or ring 15, and travels with the tow to and through the garniture 20, 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 garniture 20, and the free end of extruded element 22 is stuck to the tow upstream of funnel or ring 15; once the apparatus has been started, the advancing tow continuously entrains the extruded element 22 and draws it continuously from reel 24 via guide mandrel 48. Wrapping paper 28 is drawn continuously from reel 30 and fed continuously into the garniture 20, the paper 28 and the tow incorporating the thread 22 being carried continuously through the garniture by endless conveyor belt 32. In the garniture 20, the tow is shaped to rod form, and the paper 28 is wrapped around and secured with a lapped and stuck seam; member 34 applies a line of adhesive to one edge of paper 28, before the overlapping edges are bought into engagement. The continuously produced wrapped rod 36 passes to a cutter 38 which severs the rod 36 into individual lengths 40 each of which include a continuous extruded element of cellulose acetate. The lengths 40 may be single filter or filter elements, but, more usually, will be multiple double or higher multiple (usually quadruple or sextuple) lengths for subsequent use, as is well known. The above apparatus is well known and discussed in, for example, U.S. Pat. No. 4,281,671.
(8) It will be appreciated that in an alternative to the embodiment shown the extruded element may be drawn directly from an extruder. In other words, the extruded element may be produced (by extrusion) on site simultaneously and in-line with rod production, rather than being pre-produced and stored on a reel, and drawn from the reel as and when needed.
(9) FIG. 3 is a perspective, part cut away, view of a filter element 1. Filter element 1 includes a substantially cylindrical rod 2 of tobacco smoke filtering material in the form of a cylindrical cellulose acetate plug of length 18 mm and circumference of around 25 mm. The substantially cylindrical rod 2 is made from cellulose acetate tow which has been gathered and condensed into rod form by methods which are well known in the art (see above). Filter element 1 includes a continuous extruded element 7 extending longitudinally through rod 2, formed from extruded cellulose acetate. The continuous extruded element 7 also includes a green pigment, but it will be appreciated that other pigments (blue, red etc.) may be used, or the continuous extruded element 7 may be white. The continuous extruded element 7 is of hollow, circular, cross-section, that is, is a hollow tube (a hollow tubular element of circular cross section), and extends through the body of the rod 2 from one end of the filter element to the other, thus presenting a green ring at each end of rod 2, which contrasts with the white colour of the cellulose acetate tow which has been gathered and condensed into rod form. The continuous extruded element 7 has, applied thereon, menthol. The menthol may be applied e.g. by the methods discussed in U.S. Pat. No. 4,281,671. Methods of preparing extrusion grade cellulose acetate powder are known (e.g. see U.S. Pat. No. 4,228,246). Extrusion-grade cellulose ester pellets are commercially available from Rotuba Extruders of Linden, N.J. under the trade mark Naturacell. The extrusion-grade cellulose ester pellets are converted into an extruded element, and pigmented, by methods well known in the art. Filter element 1 includes a paper wrapper 8 surrounding longitudinally extending core 2 which may be perforated (not shown) or air-permeable to provide a ventilated filter. In a further example (not shown) the continuous extruded element 7 is of hollow, star shaped, cross-section, that is, is a hollow tube (a hollow tubular element of star shaped cross section), and extends through the body of the rod 2 from one end of the filter element to the other, thus presenting the green outline of a star at each end of rod 2, which contrasts with the white colour of the cellulose acetate tow which has been gathered and condensed into rod form.
(10) It will be appreciated that the filter element 1 of FIG. 3 may be joined at its upstream end 9 to another segment of a multi segment filter.
(11) It will be appreciated that filters and filter elements of this example of the invention may be made by methods other than those described above. For example, the filter or filter elements of the invention may be made using devices and/or processes which introduce the continuous extruded element (e.g. of cellulose acetate) or elements in a precise location or locations in or across the cross sectional area of the filter body, or on the surface of the filter body.
(12) It will be appreciated by the skilled man that filters or filter elements of other examples of the invention may be made by methods which are well known in the art.
