TIPPING ASSEMBLY FOR AN ELONGATE SMOKING ARTICLE

Abstract: A tipping assembly for a cigarette comprises an open-­ ended tube 30 provided with a plurality of apertures 60 spaced round its circumference, and a tipping wrapper 20 surrounding the tube, the tipping wrapper being provided with perforations 70 in the region overlying the apertures 60. The perforations 70 are substantially smaller than the apertures 60.

Description: TIPPIK; ASSF'.(BLY FOR AN F1N3ATE S\.OKI ARTICLE This invention relates to a tipping assembly for an elongate smoking article, such as a cigarette. Traditional methods of achieving low,tar yields from a cigarette.in combination with high nicotine levels and leo carbon monoxide levels use high levels of filtration and ventilation, but have the disadvantages of a high pressure drop perceived b the smoker and a reduced subjective response compared with the pressure drop and subjective response associated with a non-filter cigarette. It is an object of thepresent invention to provide a tipping assembly that substantially reduces the above disadvantages. According to the present invention there is provided tipping assembly for an elongate smoking article, the assembly comprising an open-ended tube provided with a plurality of apertures) spaced round the circumference of the tube, thereby dividing the tube into two sections and-providing sommunication between the inside and outside of the tube, and a tipping wrapper. surrounding the tube, characterised in that said portion of the tipping wrapper overlying the apertures is adapted to permit gas flow both through the apertures and said portion and to offer greater resistance to the gas flow than is provided by the apertures alone; The invention will non be described by way of example only with reference to the accompanying nonscaled diagrammatic drawings in which, Figure 1 is an exploded perspective view of a first embodiment of a cigarette rod and tipping assembly according to the invention, Figure 2 is a longitudinal cross-section through the cigarette roland tipping assembly of Figure 1, when assembled, Figure 3 is an exploded perspective view of a secondembodimcnt of a cigarette rod and tipping assembly according to the invention, Figure 4 is a longitudinal cross-section through the cigarettc rod and tipping assembly of Figure 3, when assembled, Figure 5 is a longitudinal section through a third embodiment of a tipping assembly according to the invention, in combination with a tobacco rod, Figure 6 is an exploded perspective view of the tipping assembly of Figure 5, Figure 7 is a longitudinal section through a fourth embodiment of a tipping assembly according to the invention, in combination with a tobacco rod, Figure 8 is an exploded perspective view of the tipping assembly of Figure 7, Figure 9 is a lateral section through the tipping assemblies of Figures 5 and 7 taken at line IX-IX, Figure 10 is an exploded perspective view of a fifth embodiment of a tipping assembly according to the invention, and, Figure 11 is an end view of the tipping assembly of Figure 10 taken in the direction of arrow XI. Referring to Figures 1 and 2 there is shown a cylindrical tobacco rod 10 enwrapped in cigarette paper 15, and a tipping assembly indicated generally at 100. The tipping assembly 100 comprises an open-ended polyethylene tube 30, 25 mm in length, wrapped in tipping paper 20 by means of which the tube 30 is attached to the tobacco rod 10. The polyethylene tube 30 is provided with four apertures or slots 60 each 3 mm long and 1 mm wide and extending through the wall of the tube 30. The longer axis of each slot 60 is parallel to the longitffdinal axis of the tube 30. The slots 60 are equidistantly spaced round the circumference of the tube 30 about half-way along the tube. The tipping paper 20 is provided with a circumferential series of perforations 70 overlying the slots 60. Typically, the perforations 70 are of 0.80 rnm diameter or less. Referring to Figures 3 and 4 there is shown a second embodiment comprising a tobacco rod and tipping assembly similar to that shown in Figures 1 and 2, identical features retaining the same numbering, and further provided with a sheet 50 of porous plug wrap material (of porosity 850-1600 Filtrona K units) between the tube 30 and the perforated tipping paper 20 and a 5 mm plug 40 of acetate filter material at the mouth end of the tube. In this embodiment the tube is 20 mm in length, making an overall tube and plug length of 5 mm. In an example, cigarettes provided with tipping assemblies according to the embodiments of Figures 1/2 and 3/4 were prepared and compared with a conventional filter cigarette (the control) using standard methods of analysis on a smoking machine and were also subjectively assessed by a smoking panel. All the cigarettes in the example, both those of the invention and the control, each had an overall length of 84 mm, a tobacco rod length of 59 mm, a circumference of 25 mm, joining paper length of 29 mm, an oven dry density of 226 kg/cubic metre, a rag nicotine content of 2.55%, and a rag sugar content of 15.55 The tipping wrapper of each of the cigarettes of the invention was perforated with four holes, one hole above each slot in the tube. The four holes were each about 0.8 mm diameter and 0.75 mm diameter for the embodiments of Figures 1/2 and 3/4 respectively. The results of the comparisons on the smoking machine are shown in the accompanying Table 1. Table 1 Control Fig.l/2 Fig.3/4 Filter type acetate tube tube + acetate Nominal nicotine retention So 63 0 15 Nominal ventialtion % 50 80 75 Nominal rag nicotine % 2.6 2.6 2.6 Puff number 9.7 10.0 9.7 PM wnf, mg/cig 4.5 5.5 5.5 Smoke nicotine, mg/cig 0.56 0.93 1.01 Tip dilution % 48.3 79.5 75.6 Pressure drop, mm H20-V0 125 7 31 Pressure drop, mm H2O-VC 176 40 61 Tip retention % 65.3 - 14.8 CO, mg/cig 5.8 1.5 2.0 Smoke pH 6.38 6.91 6.82 PM/Nicotine ratio 8.0 5.9 5.4 CO/PM ratio 1.30 0.27 0.36 Note: "PM wnf" is an abbreviation for "Particulate material (i.e. tar), water and nicotine free". It will be observed from Table 1 that, compared with the control, both the emboiments of the invention had lower pressure drops, as would be expected. This had little effect on the dynamic burn rate, and puff numbers for the control and both the embodiments of the invention were similar. Likewise, particulate matter yields for all three cigarettes were reasonably matched. However, it was found that, (i) smoke nicotine for the cigarettes of the invention was increased significantly over that of the control; (ii) carbon monoxide was greatly reduced for the cigarettes of the invention compared with the control; and, (iii) the CO/PM (carbon monoxidelparticulate material) ratios for the cigarettes of the invention were low beyond expectation for a 5 mg tar cigarette compared with the control. The smoking panel results showed that the embodiment of Figure 1/2 gave the highest scores for flavour amplitude impact and perceived smoke per puff. These scores were reduced in the embodiment of Figure 3/4 but were still significantly higher than those attributed to the control. The scores obtained in respect of the invention were similar to those expected from at least a 10 mg tar filter cigarette of conventional design. Referring now to Figures 5,6 and 9 there is shown a third embodiment of the invention comprising a cylindrical tobacco rod 110 enwrapped in cigarette paper 115, and a tipping assembly indicated generally at 1000. The tipping assembly comprises a cellulose acetate filter rod 200 of conventional construction and in abutment therewith an open-ended polyethylene tube 130 wrapped in tipping paper 120 by means of which the tube and filter rod are attached to the tobacco rod. The tube 130 is divided into two tubular sections 131 and 132 by three apertures 160 extending round the circumference of the tube 130 and separated by three narrow integral webs 161 of the material of the tubing which hold the two sections 131,132 in a fixed relationship apart from each other. The tipping paper 120 is provided with a circumferential series of perforations 170 overlying the apertures 160. Typically, the perforations 170 are 0.8 mm diameter or less, considerably smaller than the width of the apertures 160, which is about 2 mm. Referring to Figures 7,8 and10 there is shown a fourth embodiment comprising a tobacco rod and tipping assembly similar to that of Figures 5,6 and 9, identical features retaining the same numbering, and further provided with a plug 140 of cellulose acetate filter material at the mouth end of the tube. In this embodiment the tube 130 is substantially shorter than the tube of Figures 5 and 6. Referring to Figures 10 and 11 there is shown a fifth embodiment similar to that of Figures 5 and 6 except that the separated sections131,132 of the tube 130 are held in a fixed relationship to each other not by integral webs but by rectangular vanes 180 of polyethylene extending longitudinally within the tube 130 from one section to the other and radially outwards from the longitudinal axis of thetube to a distance at least equal to the internal radius of the tube. In further embodiments, not illustrated, any of the third, fourth, and fifth embodiments may be modified by the incorporation of a sheet of porous plug wrap material (of typical porosity 200-1600 Filtrona K.units) between the tube and the tipping paper. The tube 130 may be divided into its sections 131, 132 by a number of apertures 160 other than three together with the respective number of webs 161 in order to suit specific smoking requirements. The tube may be filled partly or wholly with highly porous material such as cellulose acetate in the sections 131 or 132. For instance, the filter rod 200 may at least in part occupy section 131. The tipping assembly of the invention shows that it is possible to achieve low tar yields with high nicotine, lo carbon monoxide, and acceptable smoking panel ratings, compared with conventional filters which utilise high levels both of filtration and dilution. Perforations in the tipping wrapper may be provided by a large number of small perforations or by a small number of relatively large perforations, The tipping wrapper may alternatively be adapted to permit gas flow through the apertures in the tube by providing a tipping wrapper having a very high porosity rather than by providing perforations. The tube may be made of impervious material other than polyethylene, such as cardboard. Other shapes, sizes, positions, and numbers of apertures in the tube may be contemplated in further embodiments of the invention.

Claims: CLAIMS 1. A tipping assembly (100) for an elongate smoking article, the assembly comprising an open-ended tube (30) provided with a plurality of apertures (60) spaced round the circumference of the tube, thereby dividing the tube into two sections and providing communication between the inside and the outside of the tube, and a tipping wrapper (20) surrounding the tube, characterised in that the portion of the tipping wrapper (20) overlying the apertures (60) is adapted (70) to permit gas flow both through the apertures and said portion and to offer greater resistance to the gas flow than is provided by the apertures alone. 2. An assembly as claimed in claim 1 wherein said portion of the tipping wrapper (20) is adapted to permit gas flow therethrough by means of perforations (70), the perforations being substantially smaller than the apertures (60). 3. An assembly as claimed in claim 1 or 2 wherein the apertures (60) are provided by slots. 4. An assembly as claimed in claim 3 wherein the major axes of the slots (60) are parallel to the longitudinal axis of the tube. 5. An assembly as claimed in claim 3 wherein the slots (160) are defined by a plurality of webs (161) of tube material parallel to the axis of the tube. 6. An assembly as claimed in claim 5 wherein the width of each web (161) is substantially less than that of an adjacent aperture (160). 7. An assembly as claimed in any preceding claim wherein there is provided a sheet of porous plug wrap material (50) between the tube (30) and the tipping wrapper (20), at least in the region overlying said apertures (60). 8. An assembly as claimed in any preceding claim wherein a first rod (200) of filter material is provided in axial abutment to, or inserted in, that end of the tube (130) distal to the mouth end, and a second rod (140) of filter material is provided in axial abutment to, or inserted in, the mouth end of the tube (130). 9. An assembly as claimed in claim 1 wherein the two sections (131,132) of the tube are axially spaced apart from each other and there is provided means (180) to hold the sections fixed relative to each other and to provide the plurality of apertures. 10. An assembly as claimed in claim 9 wherein the holding means is provided by a plurality of rectangular vanes (180) extending longitudinally within the tube from one section to the other and radially outwards from the longitudinal axis of the tube to a distance at least equal to the internal radius of the tube.

Inventors: BALE, CHRISTOPHER RALPH, BASSETT, DAVID WYN, GILL, BERESFORD ROY
Applicants: IMPERIAL TOBACCO LIMITED
Application year: 1983
Main classification: A24D3
IPC codes: A24D3