NL8200141A - CIGARETTE FILTER. - Google Patents

Description

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Br / Bl / lh / 9 Cigarette filter.

The invention relates to cigarette filters and provides a cigarette filter rod consisting of a plug of tobacco smoke filtering material, a tube wall centered with it in the longitudinal direction, which extends to one end of the rod and a casing around the plug and the pipe wall, whereby the rod has a cavity extending from the plug and midway through the pipe wall to the open end of the rod, and which casing or casing and pipe wall, when used on the filter rod, is sucked in respectively. ensure lateral entry of outside air into the cavity.

In some embodiments, the tube wall extends from the plug and consists of a porous air permeable material, for example, tobacco smoke filter material, and is therefore the casing present pierced and / or is it inherently air permeable? instead, the pipe wall could consist of inherently air-impermeable material (for example, a sleeve of plastic material or cardboard) with openings therethrough, the enclosure therefore comprised of air-permeable material and / or punctures, which: i; n connect to the openings in the pipe wall. When the pipe wall is made of air-permeable material, it can also have openings therethrough to facilitate the lateral entry of outside air.

In other embodiments, the pipe wall is longitudinally spaced from the plug and the casing allows for lateral entry of outside air through the casing into the space between the plug and the pipe wall. In these cases, the pipe wall may be impermeable and the ventilation will take place directly in this space, or the casing and the pipe wall may be the same as described for the former embodiments, allowing some lateral entry of outside air through the casing, 8200141 * -2- and the wall is possible. As with all embodiments, the sheath may be pierced and / or may be of inherent air permeable material when the air is to pass laterally.

The types of filter rods according to the invention described above, when used in a filter cigarette, will usually be connected to the enveloped tobacco rod by an external mouthpiece casing; the external nozzle casing will usually consist of a substantially air-impermeable material which has penetrations in the region surrounding the tube wall and / or (in the embodiment where such a space is present) around the space between the plug and the pipe wall.

With filter rods according to the invention there will usually be practically no lateral entry of outside air into the plug. The outside air entering laterally into the cavity may be the only air dilution or ventilation provided by the use of the filter rods of the invention through the combination of plug, tube wall and casing. With filter cigarettes, which are combined with filter rods according to the invention, the cigarette paper around the tobacco rod is preferably practically impermeable and the air dilution or ventilation takes place almost only via the filter rod; if the cigarette paper is substantially air permeable, the degree of air dilution and CO removal will unacceptably vary as the cigarette is smoked and will decrease from the first to .30 puff with an unacceptably low flavor release on the first puffs.

The different dimensions of the filter rods according to the invention (for example lengths of the plug and the pipe wall and of possible space between them, thickness of the pipe wall) and the structure and composition of the components can be chosen to cover the total of required properties - for example pressure drop , degree of air dilution, filtration efficiency - to be provided; the filter properties ....... 82 0 0 1 4 1 -3- will, depending on the properties of the coated tobacco rod with which the filter is to be used, be designed to provide a filter cigarette with the required smoking properties .

With filter rods according to the invention the device is preferably such that the major part (preferably the major part, for example almost the whole) of the pressure drop as a result of the combination of plug and pipe wall is provided by the plug and correspondingly little (for example virtually no) pressure drop is delivered through the pipe wall section.

It is known that ventilated cigarette filters or air-diluted cigarette filters reduce the amount of harmful CO emitted by the filter cigarette; in known filter constructions, however, the reduction in CO emission is generally proportional to the degree of air dilution, which is, however, paired with a corresponding proportional decrease in the release of flavor components to the smoker, so that a desired strong CO reduction due to a high degree of air dilution has given rise to an unacceptably tasteless smoke.

In tests with cigarettes, which are provided with filters - according to the invention with the open end of the cavity against the tobacco rod, an unexpectedly high degree of CO reduction in the released smoke has been found for the respective degree of air dilution without an excessive reduction. of the release of flavor components.

In other embodiments of the invention, the filter cavity at the mouth end of the filter cigarette is open, the device preferably being such that the filter pressure drop is largely or substantially entirely in front of (i.e., toward, the tobacco rod) the region of the lateral entry of outside air into the cavity takes place - for example, where the filter and the tobacco rod are connected by an external nozzle casing with perforations for ventilation, which perforations will preferably be arranged after the plug. With such filter cigarettes according to the invention, in particular filter cigarettes, in which the filter pressure drop takes place almost entirely before the ventilation area, the tar yield can be reduced more by air dilution than by mechanical filtration. Known conventional filters, which are designed for a small mechanical filtration efficiency with a high air dilution, have the serious disadvantage that they exhibit a too small pressure drop, which is frustrating and unacceptable for the smoker. However, in the filter cigarette of the invention, wherein the plug portion is opposite the tobacco rod and the mouth portion cavity portion is open, high levels of ventilation can be provided at acceptable total pressure drops and a desired low degree of retention (mech-15). filtration). The high air dilution, low retention filter cigarettes of the present invention, with the mouth end cavity open, may have CO / tar yields less than those achievable when using conventional filters.

The filters according to the invention, the cavity of which is open at the nozzle end, can provide a pleasant end appearance both before and at the end of smoking, because, since the smoke exits through the cavities, the material of the pipe wall during the smoking is practically not polluted and thus retains its initial clean appearance from start to finish.

Filter rods of the invention will usually be produced continuously in endless lengths, which are cut to the required finite lengths for handling and use. For example, in the making of filter cigarettes, a double-length filter rod is usually inserted between and through an external mouthpiece casing joined with a pair of tobacco rods, after which the assembly is separated in the center to provide two filter cigarettes; and the initially manufactured endless rod will usually first be cut to multiple (e.g. sixfold) lengths for delivery to the filter cigarette manufacturer, which will cut these units to multiple 8200141 Φ Λ -5 length units for use in production, as described above.

The invention therefore also encompasses the continuously manufactured bars of alternating plugs and tube walls with the casing around them and the bars of multiple and double lengths obtained therefrom by cutting the plug and / or tube wall section crosswise . The plug and tube wall sections may abut or be longitudinally spaced apart.

The invention is illustrated only by way of example with reference to the accompanying drawings, in which

Figure 1 shows a schematic longitudinal view of a filter cigarette, which is provided with a filter rod according to the invention, with the filter cavity towards the tobacco open;

Figure 2 shows a similar schematic view of a filter cigarette, which is provided with another filter rod according to the invention, with the filter cavity 20 still open to the tobacco; and

Figures 3 and 4 show similar schematic images of resp. filter cigarettes are with filters according to the invention, wherein the filter cavity at the mouth end is open.

The figures, in which like reference numerals indicate the same parts, are not to scale.

The filter cigarette shown in Figure 1 has a conventional tobacco rod 2, which is enveloped with a conventional substantially air-impermeable cigarette paper 4 and is connected to a filter 6 according to the invention by a conventional external mouthpiece casing 18 of substantially air-impermeable paper . The filter 6 has a plug 10 of tobacco smoke filtering material which abuts against a pipe wall 12 of tobacco smoke filtering material, the two of which are joined together by an air-permeable casing 14. The plug 10 can be any conventional smoke filter element, for example corrugated paper or cellulose acetate filaments bonded together at contact points, while the separate tube wall 12 may similarly consist of smoke filtering material. The outer mouthpiece casing 8 circumferentially has a ring of bores extending therethrough around the tube wall 12, thereby providing air vents 16 whereby, when the cigarette is sucked during smoking, casing 14 and tube wall 12 enter the cavity 18 is sucked.

For example, the plug 10 may consist of bonded cellulose lose acetate threads and be made as described in British Patent No. 1,169,932. The tube wall 12 may consist of the same material, which is, for example, manufactured as described in the latter patent but with a central mandrel extending through the bore 15 of the steam chamber, or as described in British patent no. 970,817. The tube wall 12, although composed of inherently permeable material, may have lateral holes, as indicated by the broken lines at 20, to facilitate dilution with air; such openings are essential for the purposes of the invention if, as in other embodiments of the construction shown, the tube wall 10 is made of an inherently impermeable material.

The embodiment shown in figure 2 differs in that the plug 10 and the tube wall 12 are separated from each other by a space 22, the bores 16 in the outer casing 8 being arranged in a ring around this space. For example, the plug 10 may have a length 30 of about 10 mm, the space 22 a length of about 5 mm, and the tube wall 12 a length of about 15 mm, wherein the plug, the tube wall, and the plug shell may consist of materials, as noted with regard to figure 1.

Below is a specific example of a filter cigarette, with which a filter according to the invention of the construction type, as shown in the accompanying drawing, is combined.

8200141 -7-

Example

Filter cigarettes of the type shown in Figure 1 were made by standardized cigarette tobacco rods 2 (coated with conventional low porosity cigarette paper 4) with the resp. unite filter rods 6 using a conventional Ecusta external mouthpiece casing 8, which is impermeable paper casing with three ring bores 16 instead of the single ring / as shown in the drawing.

In either case, the plug 10 consisted of 10 an uncoated porous plug of bonded cellulose acetate 3 threads (2.5 denier wire titer / total 56 x 10 denier) with a length of 10 mm and a pressure drop (PD) of about 67 mm, the tube wall 12 similarly consisted of a porous wall of bonded cellulose acetate threads and was 15 mm in length and. 1-2 mm thick and had no lateral openings 20, and the plug 10 and the tube wall 12 were held together to form a filter rod according to the invention by a plug wrapper 14 of porous paper with an air permeability of 100 K, as on the The manner described below was determined. The filtered cigarettes were designed to provide about 50% by volume air dilution (ventilation).

20 of such substantially identical filter cigarettes were smoked (on a standardized smoking machine 25 according to the standardized smoking test regulations) with the vents 16 open and 20 were smoked in a similar manner with the vents closed; results were averaged and are listed in the table below.

In the table, the pressure drops (PD) are expressed in mm Wg (mm water30 water overpressure) as measured at an air flow rate of 17.5 ml / sec; TPM means total amount of particles of the material and WNF means free of water and nicotine.

8200141 -8-

TABLE

Air vents Open air vents

Vol% vol. Via filter rod 6 47.7

Vol% ventilation via cigarette casing 4 7.5 «M..I.

Total PD of cigarette mm Wg -89 113 5 PD of filter rod mm Wg 67 RPM Yield mg / sig. 10.5 2l, 0 RPM (WNF) "" 8.6 16.5

Nicotine "* * 1.13 1.55 CO" "4.99 16.73 10 Nicotine retention% 37.5 37.5

Puffs / cigarette 9.4 8.1% reduction TPM 48.6 TPM (WNF) 47.9 15 Nicotine 27.1 CO 70.1 CO / TPM (WNF) ratio 0.58

It will be understood that the filter rods 20; according to the invention (air vents 16 open) provided an excellent reduction in the CO emission, which reduction is greater than that which can be achieved at the same percentage of air dilution with conventional ventilated filters.

Figures 3 and 4 illustrate filter cigarettes according to the invention, which are made from substantially the same components as those of the embodiments of Figures 1 and 2, but with the filter portion reversed, so that the cavity 18 at the mouth end is open. For example, in Figures 3 and 4, the plug 10, the tube wall 12, the shell 14, and the external nozzle shell 8 can be made from the same resp. materials exist and have the same dimensions as proposed above with respect to Figures 1 and 2.

In each of the cases of the plug 1Ö adjacent to the enveloped tobacco rod 2 35 provide a relatively low retention of particulate material, but provide almost the entire pressure drop of the filter while the air dilution through bores 16 takes place entirely past the plug 10 in the cavity 18, allowing a high degree of air dilution 5 and low mechanical retention at an acceptably high total pressure drop.

In the description of the invention, an air permeability of nK means an air permeability of nx 1000 ml / min / 10 cm / 100 mm Wg pressure - as determined by measuring the pressure "p" in mm Wg (water overpressure) being developed at a flow of 1050 ml of air per 2 minutes through 10 cm of paper and calculate from the equation;

air permeability = 1050 x 1QQ

P

* 8200141

Claims (11)

1. Cigarette filter rod characterized by a plug of tobacco smoke filtering material, a longitudinally centered tubular wall extending therewith to one end of the rod, and a casing around the plug 5 and the tubular wall, whereby the rod extends from the plug and has a cavity extending through the tube wall to the open end of the rod, and which casing or casing adheres to the pipe wall when the filter rod is sucked in use. ensure the lateral entry of • air from outside into the cavity. Filter rod according to claim 1, characterized in that the pipe wall extends from the plug and consists of air-permeable material. Filter rod according to claim 1 or 2, characterized in that the pipe wall is a pierced element which abuts the plug. Filter rod according to claim 1, characterized in that the pipe wall is a separate element, which is longitudinally spaced some distance from the plug, and the part of the casing around the space between the plug and the pipe wall is made of air-permeable material. and / or pierced. Filter cigarette characterized by a filter rod according to any one of the preceding claims, wherein the tube wall is located between the plug and the tobacco rod. Filter cigarette characterized by a filter rod according to any one of claims 1-4, wherein the plug is located between the tube wall and the tobacco rod. A filter rod, characterized in that the rod 30 can be cut transversely into separate cigarette filter rods according to claim 1 and consists of plugs of tobacco smoke filtering material which are alternated along the rod by tube walls centered longitudinally therewith and casing about the plug and pin walls, through which the rods have cavities, extending from each plug and through each adjacent pipe wall, which casing or casing and the tubing walls resp. ensure lateral entry of outside air into the cavities. Filter rod according to claim 7, characterized by a cavity at each end. Filter rod according to claim 7, characterized by a plug at each end. 10. A filter rod according to any one of claims 7-9, characterized in that each pipe wall is located against the adjacent plug and is pierced and / or consists of an air-permeable material. A filter rod according to any one of claims 7-9. characterized in that adjacent plugs and tube walls are longitudinally spaced apart while the casing is pierced around each of these spaces and / or consists of air-permeable material. 8200141