DE3246898A1 - TOBACCO SMOKING FILTER - Google Patents

Description

The present invention relates to a tobacco smoke filter according to the preamble of claim 1. Also relates to the invention filter rods for such filters.

The present invention provides a novel inhomogeneous tobacco smoke filter rod and a ventilated one Tobacco smoke filter with a stick of the same general Type indicated that the tar release mainly by air dilution and not by mechanical filtering while ensuring a pressure drop across the filter compared to a conventional one Filter with the same tar retention and air dilution is relatively high, e.g. compared with a conventional homogeneous filter, which cellulose acetate filaments with 12 or 15 DpF (denier per filament) contains and has a correspondingly low filter efficiency when the filter with a high degree of air dilution is used, but the pressure drop of the filter or the filter cigarette is unacceptable.

20 is reasonably low.

According to the present invention, a filter rod is used in which the filter material is a layer around

a denser, flow-hindering fiber or filament core forms, the latter can be impermeable to smoke or a very low smoke permeability exhibit.

In accordance with one aspect of the present invention, there is provided a tobacco smoke filter rod comprising a layer of Tobacco smoke filter material contains, which around a denser, the flow obstructing, thin or pulled down Surrounds core of connected fibers.

In accordance with another aspect of the invention, a ventilated tobacco smoke filter is provided which reduces tar delivery more through air dilution than mechanical Filtering reduced and in which a smoke filter material a layer around a denser, the flow obstructing Forms fiber or filament core and is in turn surrounded by an air-permeable covering or wrapping. With a filter cigarette with such a ventilated one

20 filter is the percentage of air dilution by the

Filters preferably greater than the percent "unventilated" tar removal of the filter, i.e., the Tar separation, which can be achieved with an equivalent filter and an equivalent cigarette with the prevention of air

25 dilution through the filter was measured.

The filter according to the invention has of course an air-permeable envelope or wrap, e.g. made of substantially impermeable paper with perforations therethrough; the air dilution of the smoke should preferably be at least 50% when using the filter. With cigarettes made with those according to the invention Filters are provided, a CO / tar ratio can be achieved, which is lower than at

35 cigarettes with conventional, highly ventilated

Filtering (where this ratio is generally around 1) while simultaneously pulling or Flow resistance has values similar to those of conventional unventilated or unventilated cigarettes

5 is comparable to only slightly ventilated filters.

The pressure drop across the entire filter is due to the reduced cross-sectional area of the filter material kept at a reasonable level. The mechanical efficiency of the filter is reduced because of this Cross-section as well as low because of the low efficiency of the filter material itself.

Under the percentage of air dilution, the amount of air added by the filter in percent by volume should be used here based on the total mixture that is released by the filter. 50% ventilation or Air dilution means that the ratio of added air to original smoke is 50/50 parts by volume amounts to; Accordingly, 40% air dilution means a ratio of 40/60 etc.

The enclosed filter (i.e. when air dilution is prevented) should preferably have a pressure drop of at least 90 mm water column (WS) and a mechanical Tar retention of. have at least 45%.

The filter material can be a conventional low filter efficiency material such as cellulose acetate or other fiber material with 8 DpF or more (as tow or staple fibers) or a pooled be corrugated sheet material.

The denser fiber or filament core obstructing the flow can be impermeable or made of one Consist of material with low permeability, e.g. made of fiber or fiber material with low permeability, e.g. a dense, thinly drawn rod of connected cellulose acetate fibers. A suitable material is available under the trade name "Transorb". The properties of such rods and procedures for their Manufacture (in which an initial curl of the filaments can be removed) are in GB-PS 970,817, from which further details can be found.

In the case of a core of low permeability, there may be a radial flow of smoke or air between the core obstructing the flow and the filter material by wrapping or a jacket (e.g. made of a non-porous paper or an impermeable) or by an integral skin surrounding the core will.

The one surrounded by the filter material and obstructing the flow

Core can extend over the entire length of the filter or

extend only over part of the filter length. In cases in which the core obstructing the flow does not extend from one end of the filter to the other, it can start at a free end or be spaced from both ends. The disabling core becomes ordinary run parallel to the filter axis and be arranged coaxially to the filter, but this is not essential necessary. The filter according to the invention can of course also have two or more flow-restricting elements Contains cores of the type described above. The filters according to the invention are easy to manufacture, by making the web or belt of the smoke filter material transported in a continuous longitudinal direction

continuously a continuous flow obstructing core or longitudinally spaced pieces of one applying such a flow obstructing core at a distance from one another, the arrangement continuously so summarizes a rod that the filter material surrounds the core or the core pieces, the rod-shaped structure then continuously with an air-permeable envelope surrounds, and cut the endless product thus obtained into pieces of the desired lengths.

If a perforated tip wrap and one extending only part of the length of the filter Core are used, the latter can advantageously be downstream or upstream of the perforations of the cladding be arranged, i.e. at the mouth end of the filter or removed from the mouth end.

The filters according to the invention can be used alone ! 20 or as part of a multiple filter together with at least one additional plug of low pressure drop and low tar retention.

The values given here for pressure drop, tar retention and air dilution are with procedures measured by CORESTA (Center de Cooperation pour les Recherches Scientifiques Relatives au Tabac) have been recommended.

When the arrangement of the flow obstructing core and the surrounding filter material after manufacture is self-supporting, the air-permeable envelope can be applied after the endlessly manufactured assembly has been cut into pieces; the wrapper can, for example, be the tip wrap be holding the filter with a wrapped tobacco rod

1 connects to a filter cigarette.

Instead, an air-permeable cover can also be used during the continuous production of the arrangement raise. In this case, the filter can then be inserted into the cigarette through a ring tip or a ring wrap be inserted or the air dilution can in use both through this wrapping as the tip wrapping or the tip paper done.

It has already been mentioned that the core obstructing the flow is completely and naturally smoke-impermeable can be; however, it can also have such a structure and composition that it itself has a measurable or even significant smoke permeability, but little or no smoke permeability of the filter as a whole. The or each flow obstructing core may, for example, be a be bound filament or fiber body, which has a certain permeability, the nonetheless when using the filter is much smaller than that of the surrounding smoke filter material. If the flow-hindering core or the flow-hindering Cores naturally have a certain smoke permeability

25, they can be smoke-permeable with a

Wrapping or skin to separate it from the surrounding smoke filter material.

In a preferred embodiment of the invention, the or each flow-restricting core is a "Transorb" rod of the above-mentioned type made of bonded cellulose acetate filaments and is surrounded by conventional smoke filter material, if desired one impermeable envelope can be interposed. 35

Ι In a group of such embodiments, the flow-impeding core rod a non-sheathed "Transorb" rod of the type mentioned above made of connected, substantially de-crimped cellulose acetate filament made according to the teachings of British Patent 970,817; and the filter material surrounding it consists of connected, crimped cellulose acetate filaments. Of the Core and the surrounding filter rod each extend over the full length of the filter, which is with is surrounded by a highly permeable (150 K) plug casing. In the following examinations of filter cigarettes were the aforementioned wrapped filter tips on conventional wrapped tobacco rods (with a Pressure drop of 45 mm WS) connected by a conventional lace wrap made of an impermeable Material existed, but had a perforation so that normal smoking would meet the requirements Adjusted the degree of air dilution. Details of three specific examples are given in

Table I listed below.

TABLE I.

Example filter material core material core top top Dr.Abf. Tar-

(Cable) (cable) 0 (mm) length circumference tip section

(mm) (mm) (mm WS) (%)

8/54 1.6 / 70 4.5 25 24.61 101 42

8/54 1.6 / 70 4.6 25. 24.61 118 45
3. 8/54. 1.6 / 70 4.5 25 24.61 92.00

CD OO CD OO

The indication "8/54" in the rubric "Filter material" means that it is a cable with the filament denier 8 and the total denier 54 χ 1O. The information "1.6 / 70" in the "core material" category has a corresponding meaning. The tip pressure drop is the pressure drop measured in mm water column at the enclosed filter tip alone, with a lateral Entry of air was prevented. The percentages under the heading "tar separation" mean the non-ventilated Retention of tar when smoking a filter cigarette of the above type under standard conditions on a Filtrona 300 smoking machine with the tip wrapper perforation closed.

Table II shows the pressure drop characteristics of the filter alone and the ventilated filter cigarette according to Example 1 compared with those of filters and filter cigarettes, in which the filter is a more uniform Plugs made from connected, crimped cellulose acetate filaments of coarse or conventional fiber strength duration. The comparison values apply as in Example 1 for a tip length of 25 mm, a tar separation of 42% with no ventilation and a tobacco stick with a pressure drop of 45 mm WS.

TABLE II

Pressure drop measurement (mm WS)

Included tip

Filter cigarette, air holes open, 50% valve.

Ex. 1 Coarse (12 DpF) Conventional Cellulose Acetate Cellulose Acetate

(2.5-5 DpF)

101

102

84.5

35-60

50-70

The properties for Examples 1 to 3 are given in Table III below. The smoke tests were under standard conditions with a Filtrona 300 smoking machine with the tip cover perforation open carried out. Example 1 of Table III differs from that in Table II only in that in the latter study the air dilution (ventilation) was limited to 50%. In every example the unfiltered cigarette had a pressure drop of 45 mm WS, a tar release of 29 mg *) and a CO2 emissions of 15.7 mg. The ventilated cigarette of Example 1 had a pressure drop of 95 mm WS.

example TABLE III 15th Pressure drop
Tip (mm WS) Levy - GTS (WNF)
(mg) 1 Levy - CO
(mg) 101 20th relationship
CO / GTS (WNF) 5.5 4, 1 25th 0.75

118 92

6.2 9.7

4.8 5.85

0.77 0.6

Top ventilation

62 58 50

GTS (WNF) means "total amount of particulate Substance (anhydrous and nicotine-free) ",

In the following Table IV a commercial Filter cigarette and its conventional, ventilated (homogeneous connected cellulose acetate cable) filter with a filter of the same dimensions and a *) (free of water and nicotine)

1 filter cigarette (example 4) according to the invention compared. The tobacco rods of Example 4 and the conventional, commercially available comparative cigarette are of course the same.

TABLE IV

Ventilated filter cigarette

Pressure Drop (mm WS) Peak Ventilation

GTS (WNF) levy
(mg)

CO emissions (mg)

CO / GTS (WNF) ratio

Pressure drop of the
not ventilated
Tip (mm WS)

Tar separation
without ventilation
(%)

Example 4 80 65.3

5.7 2.94

0.52 126

42

More conventional

more commercially available

comparison

89

56.4

5.0 4.09

0.82 98

53

An air permeability of nK means an air permeability of η χ 1000 ml / min / 10 cm ^2/100 mm WS pressure measured by the determination of the pressure ρ in 30 mm water column, the QCM by a flow of 1050 ml of air per minute through 10 of the test object , e.g. of the paper and calculate the air permeability K according to the equation:

Air permeability K =

χ 100

The invention also provides a tobacco filter rod that has a layer of tobacco smoke filter material contains, which has a denser, flow-restricting, thinly drawn core of connected filaments or surrounds fibers, this is the preferred shape of the present filter rod itself for the Use according to the invention with a ventilating tip wrapping or wrapping in a filter cigarette. The core filaments, such as cellulose acetate, preferably have substantially no crimp that is, they have been substantially uncrimped by the thinning of the core material during core formation or stretched. The filter material expediently consists of connected crimped filaments, e.g. from cellulose acetate. The composite rod can be covered with a plug with high (e.g. 150 K) air permeability be surrounded. If the stick itself is not covered, it can be put in a filter cigarette inserted through a ventilating tip sheath; if the rod itself is a highly breathable one Contains a stopper wrapper, it can be inserted into a filter cigarette through a ring tip or wrap or through a ventilated tip sheath, mostly through the latter, are inserted.

The filter according to the invention can by appropriate choice of the length, the core and the surrounding filter material, the structure, the packing density, the relative Cross-sectional areas and the like and the percent air dilution are designed so that they result in a ventilated filter cigarette with an acceptable total pressure drop with any given tobacco rod, e.g. 80 to 120 mm water column, especially with a currently preferred pressure drop of about 80 or about 90 or about 100 mm water column. However, you can also use ventilated filter cigarettes with a

significantly higher or significantly lower pressure drop (e.g. 70, 60, 50, 40, 30 or even 25 mm Water column) if so desired and in all cases a better result will be obtained than with the conventional filter arrangements.

In the drawing is an embodiment of a filter cigarette with a ventilated tobacco smoke filter shown schematically according to an embodiment of the invention.

The filter cigarette shown contains a tobacco rod 12 wrapped in cigarette paper 10, which passes through a wrap 14 made of a lace paper provided with a perforation 16 with a filter rod 18 connected is. The filter rod 18 contains a core 20 made of a relatively dense, the flow through A rod made of interconnected cellulose acetate filaments, practically preventing smoke and air, and a filter material 22 made of crimped acetate filaments which concentrically surrounds the core 20. In the illustrated embodiment, the core 20 begins at the mouth end of the cigarette and extends about 2/3 of the filter length. The perforation 16 is located at the end of the core 20 on the tobacco side.

The present invention thus creates tobacco smoke filters of new, inhomogeneous structures, which reduce CO preferentially over tar. This is done through a filter with a relative low mechanical efficiency in connection with relatively high air dilution achieved.

Conventional filters with a homogeneous structure made of, for example, cellulose acetate fibers of 12 DpF or 15 DpF, which is a relatively low mechanical

1 efficiency have the disadvantage that

when used in conjunction with high air dilution values, unacceptably low pressure drops across the filter or the filter cigarette. The present filters, however, have a relatively low mechanical Reluctance and on the other hand a relatively high pressure drop compared to that of conventional, homogeneously structured filters.

In this aspect, the invention provides a ventilated Tobacco smoke filter created, which preferentially reduces carbon monoxide with respect to tar and at which the smoke filter material is a layer or a layer around a denser, the flow obstructing fiber

15 or filament core forms.

Cigarettes provided with such filters according to the invention give a lower CO / tar ratio than cigarettes with the same tar output that conventional ventilated filters contain (for the this ratio has essentially the value one), since the contribution of ventilation increases and the contribution the mechanical reluctance to reduce the tar is reduced; the drag or drag however, the cigarette can be kept essentially the same.

So there is a tobacco smoke filter specified that the Tar release essentially reduced by air dilution rather than mechanical filtering and simultaneously ensures a relatively high pressure drop across the filter. It contains a filter material in the form of a layer, which surrounds a denser fiber or filament core which hinders the flow and which in turn is air-permeable Enclosure can be surrounded. The filter

material consists preferably of connected, crimped cellulose acetate filaments and the flow obstructing The core is expediently a thinly drawn rod made of connected, essentially uncrimped Filaments, e.g. made of cellulose acetate, and expediently has a very low or negligible Permeability. The filter can be inserted into a filter cigarette through a ventilating, e.g., perforated, tip wrapper be inserted, which can form the above-mentioned envelope. A tobacco smoke filter rod is also used specified, which contains a layer of tobacco smoke filter material, the denser, the flow obstructing, Contains a thinly drawn core of connected filaments.

Claims (12)

"- PAXENXAPJ W - DR. DiETE-R ν" BETZOLD DIPL. ING. PETER SCHÜTZ DIPL. ING. WOLFGANG HEUSLER MARIA-THERESIA-STRASSE 22 POST BOX 86 O2 60 D-8OOO MUENCHEN 86 GB-PA 81 38273 AT: December 18, 1981 APPROVED BY THE EUROPEAN PATENT OFFICE EUROPEAN PATENT ATTORNEYS MANDATAIRES EN BREVETS EUROPEENS TELEPHONE 6022 068-89 TELEPHONE 63 SOMBEZ 11385 Dr.vB / Ri CIGARETTE COMPONENTS LIMITED Friendly House, 21-24 Chiswell Street London EC1Y 4UD, England Tobacco smoke filter claims 1. Ventilated tobacco smoke filter, which the tar pollution more reduced by air dilution than by mechanical filtering, with a smoke filter material, thereby characterized in that the smoke filter material forms a layer around a denser, the flow obstructing fiber or filament core forms and is in turn surrounded by an air-permeable wrapping. 2. Filter according to claim 1, characterized / that the percentage Air dilution is greater than its percentage of unventilated mechanical tar retention, 5 Weil measured in connection with equivalent tobacco rods. 3. Filter according to claim 1, characterized in that it is a non-ventilated Pressure drop of at least 90 now WS and a non-ventilated mechanical tar retention of at least 45%. 4. Filter according to claim 1 or 2 with a wrapping or a jacket that separates the core from the surrounding Separate filter material. 5. Filter according to one of the preceding claims, characterized in that the core is a drawn down rod of connected, substantially uncrimped cellulose acetate filaments and that the filter material is made of connected, crimped cellulose acetate filaments consists. 6. Filter according to one of the preceding claims, characterized in that the wrap includes a tip wrap through which the filter is inserted into a filter cigarette. 7. Marked tobacco smoke filter stick through a layer of tobacco smoke filter material, which rides a denser, flow-hindering, pulled down Surrounds core of connected filaments. 8. Filter according to claim 7, characterized in that the filaments of the core are essentially uncrimped. 9. Filter according to claim 7 or 8, characterized characterized in that the filter material consists of interconnected crimped filaments. 10. Filter according to claim 7, 8 or 9, characterized characterized in that the filaments consist of cellulose acetate. 11. Filter or filter rod according to one of claims 1 15 to 5 and 7 to 10, characterized in that it is ventilated by a Tip wrap is inserted into a filter cigarette. 20th 12. Taka smoke filter, the carbon monoxide versus tar preferably reduced, with a smoke filter material, characterized in, that the smoke filter material is a layer around a denser, the flow obstructing fiber or Filament core forms.