US20050087202A1

US20050087202A1 - Apparatus for measuring a property of a cigarette paper wrapper and associated method

Info

Publication number: US20050087202A1
Application number: US10/695,495
Authority: US
Inventors: Alan Norman; Jason Caudle
Original assignee: RJ Reynolds Tobacco Co
Current assignee: SODIM INSTRUMENTATION Sas
Priority date: 2003-10-28
Filing date: 2003-10-28
Publication date: 2005-04-28

Abstract

An apparatus for measuring a property of a cigarette paper wrapper is provided and includes a sampling device having a first chamber portion capable of being engaged with a corresponding second chamber portion to define a sampling area configured to receive the wrapper such that the wrapper spans the sampling area and separates the chamber portions. A first gas source supplies a carrier gas to the first chamber portion and a second gas source supplies a detectable gas to the second chamber portion. An analyzer device in communication with the first chamber portion receives a resultant gas flow that includes the carrier gas and any of the detectable gas entering the first chamber portion through the wrapper. The analyzer device is capable of determining an amount of the detectable gas in the resultant gas flow so as to thereby determine a property of the cigarette paper wrapper, such as a diffusion coefficient with respect to the detectable gas. An associated method is also provided.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to smoking articles and, more particularly, to an apparatus for measuring a property of a paper material suitable for use as components of such smoking articles.
2. Description of Related Art
Popular smoking articles, such as cigarettes, have a substantially cylindrical rod shaped structure and include a charge, roll or column of smokable material such as shredded tobacco (e.g., in cut filler form) surrounded by a paper wrapper thereby forming a so-called “tobacco rod.” Normally, a cigarette has a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element comprises plasticized cellulose acetate tow circumscribed by a paper material known as “plug wrap.” Certain cigarettes incorporate a filter element having multiple segments, and one of those segments can comprise activated charcoal particles. Typically, the filter element is attached to one end of the tobacco rod using a circumscribing wrapping material known as “tipping paper.” It also has become desirable to perforate the tipping material and plug wrap, in order to provide dilution of drawn mainstream smoke with ambient air. A cigarette is employed by a smoker by lighting one end thereof and burning the tobacco rod. The smoker then receives mainstream smoke into his/her mouth by drawing on the opposite end (e.g., the filter end) of the cigarette.
Numerous references propose various types of cigarettes possessing various types of paper wrapping materials. See, for example, U.S. Pat. No. 1,909,924 to Schweitzer; U.S. Pat. No. 4,489,650 to Weinert; U.S. Pat. No. 3,030,963 to Cohn; U.S. Pat. No. 4,146,040 to Cohn; U.S. Pat. No. 4,489,738 to Simon; U.S. Pat. No. 4,615,345 to Durocher; U.S. Pat. No. 4,607,647 to Dashley; U.S. Pat. No. 5,060,675 to Milford et al.; U.S. Pat. No. 4,924,888 to Perfetti et al.; U.S. Pat. No. 5,143,098 to Rogers et al.; U.S. Pat. No. 4,998,543 to Goodman; U.S. Pat. No. 5,220,930 to Gentry; and U.S. Pat. No. 5,271,419 to Arzonico et al. Some paper wrapping materials are so-called “banded papers” and possess segments defined by the composition, location and properties of the various materials within those wrapping materials. Numerous references contain disclosures suggesting various banded wrapping material configurations. See, for example, U.S. Pat. No. 1,996,002 to Seaman; U.S. Pat. No. 2,013,508 to Seaman; U.S. Pat. No. 4,452,259 to Norman et al.; U.S. Pat. No. 5,417,228 to Baldwin et al.; U.S. Pat. No. 5,878,753 to Peterson et al., U.S. Pat. No. 5,878,754 to Peterson et al.; and U.S. Pat. No. 6,198,537 to Bokelman et al.; and PCT WO 02/37991. Methods for manufacturing banded-type wrapping materials also have been proposed. See, for example, U.S. Pat. No. 4,739,775 to Hampl, Jr.; U.S. Pat. No. 5,474,095 to Allen et al.; and PCT WO 02/44700 and PCT WO 02/055294. Some references further describe banded papers having segments of paper, fibrous cellulosic material or particulate material adhered to a paper web. See, for example, U.S. Pat. No. 5,191,906 to Myracle, Jr.; U.S. Pat. No. 5,263,999 to Baldwin et al.; U.S. Pat. No. 5,417,228 to Baldwin et al.; and U.S. Pat. No. 5,450,863 to Collins et al.; and U.S. Patent Application Publication No. 2002/0092621 to Suzuki. In addition, some references describe apparatuses and method for inspecting such papers and wrapping materials, some of which may be capable of operating in an automated and/or high speed process. See, for example, U.S. Pat. No. 4,845,374 to White et al.; U.S. Pat. No. 5,966,218 to Bokelman et al.; U.S. Pat. No. 6,020,969 to Struckhoff et al.; and U.S. Pat. No. 6,198,537 to Bokelman et al.; U.S. Patent Application Publication Nos. 2003/0145869 and 2003/0150466 to Kitao et al., and 2003/0197126 to Sato et al.; and U.S. patent application Ser. Nos. 10/645,996, filed Aug. 22, 2003, and Ser. No. 10/665,066, filed Sep. 17, 2003.
Since certain properties are often required to provide the desired burn characteristics and/or other characteristics of such wrapping materials and since consistency between individual paper wrappers for a particular product is also desired, it has been desirable, if not necessary, to determine certain physical properties or characteristics of wrapping materials for smoking articles. For example, techniques for measuring the air permeability or porosity of such wrapping papers, as well as the diffusion of gases, such as carbon monoxide, through such wrapping papers, have been developed. For example, the CORESTA method (CORESTA Publication ISO/TC0126/SC I N159E (1986)) details a procedure for measuring air flow through paper with a specified pressure difference across the paper. This procedure may generally provide accurate readings for large sample areas or relatively high flow rates. However, this method may also be undesirably subject to high relative errors and high variability for small sample areas and low flow rates.
Further, for example, Drake et al. (D. G. Drake, D. S. Riley, R. R. Baker and K. D. Kilbum, On a Cell to Measure Diffusion Coefficients of Gases Through Cigarette Papers, Int. J. Heat and Mass Transfer, 23 (1980) 127-134) describe a procedure for direct measurement of paper diffusion coefficients. However, this reference does not describe an apparatus suitable for measuring small band areas of a sample. In addition, Durocher (U.S. Pat. No. 4,615,345 and other patents) describes an indirect and destructive sample test producing results asserted to be proportional to paper diffusion coefficients. However, such a method is undesirably limited by destruction of the sample and the amount of time required to perform the test.
Thus, there exists a need for an apparatus and method capable of nondestructively measure certain physical properties or characteristics of wrapping papers, such as those used for the manufacture of smoking articles. Such an apparatus and method should be capable of expeditiously determining the value of the particular characteristic for the tested sample of the wrapping paper and, in some instances, would desirably have the capability of being applied in an automated and/or high speed process to perform regular or random evaluations of the paper wrappers. Further, such an apparatus and method should desirably be nondestructive to the paper wrapper, applicable to a small area of the paper wrapper (sample), cost and time effective, and capable of being implemented in an environmentally friendly manner.

BRIEF SUMMARY OF THE INVENTION

The above and other needs are met by the present invention which, in one embodiment, provides an apparatus adapted to measure a property of a cigarette paper wrapper. Such an apparatus includes a sampling device defining a first chamber portion and a corresponding second chamber portion, wherein the first and second chamber portions engage at and define a sampling area. The sampling device is configured to receive the cigarette paper wrapper such that the cigarette paper wrapper spans the sampling area and separates the first chamber portion from the second chamber portion. A first gas source is configured to supply a regulated flow of a carrier gas to the first chamber portion, while a second gas source is configured to supply a regulated flow of a detectable gas to the second chamber portion. An analyzer device in communication with the first chamber portion is configured to receive a resultant gas flow, wherein the resultant gas flow includes the carrier gas and any of the detectable gas entering the first chamber portion through the cigarette paper wrapper. The analyzer device is further configured to be capable of determining an amount of the detectable gas in the resultant gas flow so as to thereby determine a property of the cigarette paper wrapper, such as the diffusion coefficient with respect to the detectable gas.
Another advantageous aspect of the present invention comprises a method of measuring a property of a cigarette paper wrapper. First, a cigarette paper wrapper is received in a sampling device defining a first chamber portion and a corresponding second chamber portion, wherein the first and second chamber portions engage at and define a sampling area. The sampling device is further configured to receive the cigarette paper wrapper such that the cigarette paper wrapper spans the sampling area and separates the first chamber portion from the second chamber portion. A regulated flow of a carrier gas is then supplied to the first chamber portion, while a regulated flow of a detectable gas is supplied to the second chamber portion. A resultant gas flow is thereafter received at an analyzer device in communication with the first chamber portion, wherein the resultant gas flow including the carrier gas and any of the detectable gas entering the first chamber portion through the cigarette paper wrapper. An amount of the detectable gas in the resultant gas flow is then determined with the analyzer device, from which a property of the cigarette paper wrapper, such as the diffusion coefficient with respect to the detectable gas, is determined.
Thus, embodiments of the present invention meet the above-identified needs and provide distinct advantages as further detailed herein.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 is a schematic of an apparatus adapted to measure a property of a cigarette paper wrapper according to one embodiment of the present invention.
FIG. 2 is a schematic plan view of a banded cigarette paper wrapper advancing through an apparatus adapted to measure a property of a cigarette paper wrapper according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
FIG. 1 schematically illustrates an apparatus, indicated generally by the numeral 10, adapted to measure a property of a cigarette paper wrapper according to one embodiment of the present invention, wherein the apparatus 10 may be used, for example, to evaluate various types of paper wrapping materials and treated wrapping materials as disclosed in U.S. Patent Application Publication No. 2003/0131860 to Ashcraft et al., which is incorporated herein in its entirety by reference. Such an apparatus 10 comprises a sampling device 100 defining a first chamber portion 150 and a corresponding second chamber portion 200. The first and second chamber portions 150, 200 are configured to be capable of engaging about a sampling area 250, wherein the sampling area 250 is defined by one or more dimensions. The sampling device 100 is further configured to receive a cigarette paper wrapper 50 between the first and second chamber portions 150, 200. Preferably, the sampling area 250 and/or the cigarette paper wrapper 50 are dimensioned such that the cigarette paper wrapper 50 spans the sampling area 250 and extends sufficiently beyond the sampling area 250 so as to be capable of being secured between the first and second chamber portions 150, 200. For example, the first and second chamber portions 150, 200 may be movable with respect to each other so as to allow the cigarette paper wrapper 50 to be placed therebetween. Such a cigarette paper wrapper 50 may vary considerably in, for example, composition and characteristics, some of which are described in, for instance, U.S. Patent Application Publication No. 2003/0131860, also assigned to the assignee of the present invention. Accordingly, U.S. Patent Application Publication No. 2003/0131860 is incorporated herein in its entirety by reference.
In a particularly advantageous embodiment, the engaging faces of the first and second chamber portions 150, 200 are configured to be brought together, with the cigarette paper wrapper 50 therebetween, so as to form a seal therewith. For example, the engaging faces of the first and second chamber portions 150, 200 may be machined to respective flat surfaces or into any other suitable complementary configuration. However, if necessary, each of the first and second chamber portions 150, 200 may have, for instance, a gasket 140 on the engaging faces thereof surrounding the sampling area 250. Such a configuration is shown in FIG. 1, but it will be understood that the gaskets 140 may not be necessary in light of the particularly advantageous gasket-less embodiment previously described. If gaskets 140 are used, the gaskets 140 form a seal between the respective chamber portion and the cigarette paper wrapper 50 when the cigarette paper wrapper 50 is placed between the first and second chamber portions 150, 200 and the first and second chamber portions 150, 200 are brought together. In particularly advantageous instances, with or without the gaskets 140, the first and second chamber portions 150, 200 are configured to form a substantially air-tight seal about the cigarette paper wrapper 50. One skilled in the art will appreciate, however, that many different configurations for sealing the cigarette paper wrapper 50 between the first and second chamber portions 150, 200 may be possible, preferably without causing damage or deformity to the cigarette paper wrapper 50, and that the configurations presented herein are merely examples thereof. In any instance, the cigarette paper wrapper 50 essentially separates the first chamber portion 150 from the second chamber portion 200 when secured therebetween.
Each of the first and second chamber portions 150, 200 further includes a respective gas inlet port 160, 210 and a respective gas outlet port 170, 220. The gas inlet port 160 of the first chamber portion 150 is connected a gas supply 180 of a carrier gas. According to one advantageous embodiment of the present invention, the carrier gas is substantially inert, comprising, for example, nitrogen, helium, argon, or the like. Further, the gas inlet port 210 of the second chamber portion 200 is connected to a gas supply 230 of a detectable gas. In one advantageous embodiment, the detectable gas is detectable over the carrier gas. In addition, the detectable gas is preferably substantially harmless if released to atmosphere. As such, the detectable gas may comprise, for example, carbon dioxide, oxygen, or the like. Respective gas flow regulating devices such as, for example, mass flow meters 190, 240, are disposed between the gas supplies 180, 230 and the respective gas inlet ports 160, 210 for regulating the flows of the gases. In advantageous instances, the mass flow meters 190, 240 are adjustable such that substantially equal mass flows of the respective gases are directed to flow into the first and second chamber portions 150, 200 through the gas inlet ports 160, 210 such that the pressures in the chamber portions 150, 200 are also substantially equal. In this manner, the gases do not provide a driving force in either direction through the cigarette paper wrapper 50. In one advantageous embodiment, the apparatus 10 is operated such that the pressures in the chamber portions 150, 200 are close to atmospheric pressure.
The detectable gas leaving the second chamber portion 200 through the gas outlet port 220 may, in some instances, be vented directly to atmosphere. However, in other instances, where the detectable gas cannot be safely vented to atmosphere, one skilled in the art will appreciate that the waste detectable gas may be directed to a variety of devices for collecting, neutralizing, and/or otherwise converting the detectable gas into a form suitable for disposal. The gas outlet port 170 of the first chamber portion 150, however, is connected to an analyzer device 300. Such a connection can be established, for example, through the use of a sample loop (not shown) or other mechanism configured so as to avoid elevating the pressure in the first chamber portion 150 over the second chamber portion 200. The analyzer device 300 is thus configured to receive a resultant gas flow from the first chamber portion 150, wherein the resultant gas flow is comprised of the carrier gas and any of the detectable gas that diffuses across the cigarette paper wrapper 50 from the second chamber portion 200 into the first chamber portion 150. As such, in one advantageous embodiment, the analyzer device 300 is configured to be capable of conducting at least one analysis to determine the amount of the detectable gas in the resultant gas flow. Such an analysis can indicate, for instance, the diffusivity or diffusion coefficient of the cigarette paper wrapper 50 as described herein in further detail. In some instances, under the conditions in the sampling device 100, the diffusion of the detectable gas across the cigarette paper wrapper 50 may require a certain amount of time to reach an equilibrium, after which time the amount of the detectable gas in the resultant gas flow remains substantially constant. Accordingly, the analyzer device 300 may be configured, for example, to make several measurements or analyses in order to determine when such an equilibrium has been reached, or to perform the measurement following a certain elapsed time from the start of the test for the particular cigarette paper wrapper 50. For instance, the analyzer device 300 may be configured to perform the necessary measurement at between about 3 seconds and about 10 seconds after the test process is initiated.
According to one advantageous aspect of the present invention, the diffusivity of the cigarette paper wrapper 50 can be determined according to the following methodology. More particularly, a sample of a cigarette paper wrapper 50 is first placed between the first and second chamber portions 150, 200 so as to span the sampling area 250. Once the wrapper 50 is secured between the chamber portions 150, 200, a steady stream of a substantially inert carrier gas, such as N₂, is fed into the first chamber portion 150 through the gas inlet port 160 thereof, while a steady stream of a detectable gas, such as CO₂, is fed into the second chamber portion 200 through the gas inlet port 210 thereof. Since cigarette paper wrapper 50 is at least partially porous, some CO₂detectable gas will tend to migrate from the second chamber portion 200, through the wrapper 50, and into the N₂carrier gas stream (and likewise, some of the N₂carrier gas will tend to migrate through the wrapper 50 and into the CO₂detectable gas stream). The rate at which the detectable gas migration occurs is related to, for example, the diffusion coefficient of the wrapper (D_p), the binary diffusion coefficient of CO₂into N₂(D_g=0.171 cm²/s), the temperature (T), the differential pressure (ΔP), and the gas concentration differential between the first and second chamber portions 150, 200. The diffusion coefficient D_pof the wrapper 50 can be subsequently calculated, for instance, from the concentration of the detectable gas in the resultant gas flow (the measured outlet gas concentration (CO_out)) and the aforementioned parameters.
One skilled in the art will also appreciate that the concentration of the respective gas in each chamber portion 150, 200 may change along the length of the sampling area 250 (δC/δx) depending on the amount of the respective gas migrating across the wrapper 50. Likewise the concentration of the respective gas will vary over the depth of the respective chamber portions 150, 200 (δC/δz), corresponding to a distance away from the sample of the wrapper 50. Thus, taking these various factors into consideration, the resultant system of partial differential equations relating the concentration of the detectable gas in the resultant gas flow (% CO₂) in the first chamber portion 150 to the diffusion coefficient DP of the cigarette paper wrapper 50 (as discussed in D. G. Drake, D. S. Riley, R. R. Baker and K. D. Kilburn, On a Cell to Measure Diffusion Coefficients of Gases Through Cigarette Papers, Int. J. Heat and Mass Transfer, 23 (1980) 127-134, the contents of which are incorporated herein by reference) may have the general form: $\begin{matrix} θ_{m} = 2 α^{2} \sum_{n = 1}^{\infty} \frac{1}{μ_{n}^{2} [μ_{n}^{2} + α^{2} + α]} ⅇ^{- 6 μ_{n}^{2} x} & Eqn . 1 \end{matrix}$
where μ_nare the positive roots of
μ tan μ=α Eqn. 2
Further:
θ_m=2C _out /C _CO2−1 Eqn. 3
χ=bD _g x/6Ve Eqn. 4
α=2eD _p /tD _g Eqn. 5
where:

- C_CO2=input CO₂concentration=100%;
- b=chamber portion width;
- x=chamber portion length;
- V=volumetric flow rate;
- e=chamber portion depth; and
- t=wrapper thickness.

The solution is subsequently determined, for example, by a numerical iteration procedure, as follows:

- 1) Determine an initial estimate for D_p;
- 2) Calculate α using Eqn. 5;
- 3) Determine the first ten positive values for μ that satisfy Eqn. 2;
- 4) Calculate C_outas predicted by Eqn. 1;
- 5) Compare to calculated C_outto C_outactually measured; and
- 6) Increment D_pand repeat steps 2-5 until calculated C_outis within 0.01% of C_outactually measured.

D_p, expressed in units of, for example, cm²/s, describes a rate of migration through a material and is independent of the material's geometry. Further, a cigarette burn rate is at least partly governed by the amount of oxygen that diffuses from ambient through the cigarette paper wrapper 50 and into the fire coal. Accordingly, another relevant measurement may be a diffusive flux (D*) across the cigarette paper wrapper 50, expressed in terms of volume of gas per unit area per unit time (cm³/cm²/s or cm/s). D* may also be expressed as the ratio of DP and the wrapper thickness t (D*=D_p/t).
In order to simplify these calculations for routine use, D* and CO_outas calculated can be related with the aforementioned procedure at standard ambient conditions (725 torr, 299° K.) by, for example, a fourth degree polynomial regression (at least partially dependent on the dimensions of the chamber) having an applicable equation as follows:
D* _s=λ₄ C _out ⁴λ₃ C _out ³+λ₂ C _out ²λ₁ C _out Eqn. 6
wherein this equation is applicable to a chamber having particular dimensions for chamber width (b=0.4 cm), chamber length (x=2.0 cm), and chamber depth (d=0.175 cm), and
where:

- λ₄=1.530E-04;
- λ₃=−887.513E-04;
- λ₂=8.624E-03; and
- λ₁1=1.184E-01.
  D*_sthus denotes the diffusion coefficient at the standard environmental conditions and for the specific chamber dimensions described above. However, in instances where a controlled mass flow is fed into the respective chamber portions 150, 200, the volumetric flow and resultant D* must be corrected for temperature and barometric pressure, as follows: $\begin{matrix} D^{*} = D_{s}^{*} \times \frac{725}{P_{a}} \times \frac{T_{a}}{299} & Eqn . 7 \end{matrix}$
  where:
- P_a=ambient pressure; and
- T_a=ambient temperature.
  The flow rates of both the carrier gas and the detectable gas may be readily determined from the respective mass flow meters 190, 240. As such, the diffusion coefficient D_pof the cigarette paper wrapper 50 may be determined using the described apparatus 10, as detailed, according to embodiments of the present invention.

In some instances, as shown in FIG. 2, the cigarette paper wrapper 50 may be provided as a contiguous roll 350 of cigarette paper wrappers 50, wherein, in some instances, each cigarette paper wrapper 50 may comprise two contiguous bands 60, 70 though, in some instances, each cigarette paper wrapper 50 may comprise more than two bands. According to other aspects of the present invention, the bands 60, 70 can have different values of a common property, as will be appreciated by one skilled in the art. For example, one band may have a greater diffusion coefficient than the other band. When arranged along the roll 350, the bands 60, 70 are regularly repeating. As such, in some instances, the apparatus 10 may be configured to selectively perform a measurement of either or both bands 60, 70 at selected points along the roll 350. In such instances, the apparatus 10 further includes an advancement device 400 for advancing the cigarette paper wrappers 50 from the roll 350 through the sampling device 100.
One skilled in the art will further appreciate that embodiments of the apparatus 10, applicable to a roll 350 of cigarette paper wrappers 50, may be configured in many different manners. For example, the apparatus 10 may be configured to perform a measurement of each and every band 60, 70 along the roll 350. However, such a configuration may not be practical in a manufacturing process. Accordingly, the apparatus 10 may be configured so as to selectively perform a measurement at various intervals along the roll 350. For example, the apparatus 10 may be configured to measure each tenth occurrence of the first band 60 and/or the second band 70. In such instances, the apparatus 10 may further include a sensor 450 operably engaged with the advancement device 400 and capable of directing the advancement device 400 to stop the advancement of the cigarette paper wrappers 50 on the roll 350 when a certain point on the roll 350 is reached such that a particular band lies within the sampling device 100. More particularly, the sensor 450 may be configured to analyze the roll 350 so as to direct the advancement device 400 to stop the advancement of the cigarette paper wrappers 50 when only one of the bands 60, 70 is spanning the sampling area 250 within the gaskets 140. Such a sensor 450 may comprise an optical sensor, though one skilled in the art will appreciate that many different types of sensors and/or other mechanisms may be implemented to accomplish the selective stopping of the advancement of the roll 350 as described herein. For example, a registration and inspection system (not shown) may be implemented, wherein such a system may include, for instance, a detection apparatus utilizing a spectroscopic (non-optical) system such as a non-contact ultrasonic transmission system or a near infrared (NIR) absorption system.
In addition, in other instances, the apparatus 10 may also include a sensor 500 operably engaged with the analyzer device 300, wherein such a sensor 500 may be configured to determine when the advancement of the roll 350 has stopped and when the sampling device 100 is prepared for a measurement with only one of the bands 60, 70 spanning the sampling area 250. Upon sensing the necessary conditions, the sensor 500 may actuate the gas supplies 180, 230 to start the gas flows, may actuate the mass flow sensors 190, 240 to appropriately regulate the gas flows, and then actuate the analyzer device 300 to perform the measurement at the appropriate moment. However, one skilled in the art will appreciate that several sensors or other mechanisms may be implemented to perform such tasks.
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, embodiments of the apparatus 10 as described herein may be controlled by, incorporate, or otherwise include a computer device (not shown) such as a computer, controller, or the like capable of controlling any or all of the described components and/or functions of the apparatus 10. In addition, where such a computer device is included, one skilled in that art will appreciate that associated methods and computer software program products will be within the spirit and scope of the present invention. Further, one skilled in the art will appreciate that the described apparatus may be other wise configured or include additional components so as to be capable of determining other properties of the cigarette paper wrapper 50, such as, for example, a tensile strength or porosity thereof (that may be related to the diffusion coefficient D_p), other than those properties described in detail herein. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. An apparatus adapted to measure a property of a cigarette paper wrapper, said apparatus comprising:

a sampling device defining a first chamber portion and a corresponding second chamber portion, the first and second chamber portions engaging at and defining a sampling area, the sampling device being configured to receive the cigarette paper wrapper such that the cigarette paper wrapper spans the sampling area and separates the first chamber portion from the second chamber portion;

a first gas source configured to supply a regulated flow of a carrier gas to the first chamber portion;

a second gas source configured to supply a regulated flow of a detectable gas to the second chamber portion; and

an analyzer device in communication with the first chamber portion and configured to receive a resultant gas flow, the resultant gas flow including the carrier gas and any of the detectable gas entering the first chamber portion through the cigarette paper wrapper, the analyzer device being further configured to be capable of determining an amount of the detectable gas in the resultant gas flow so as to thereby determine a property of the cigarette paper wrapper.

2. An apparatus according to claim 1 further comprising a mass flow meter operably engaged between each of the first and second gas sources and the first and second chamber portions, respectively, the respective mass flow sensors being adjustable to regulate the flows of the carrier gas and the detectable gas such that substantially equal mass flows thereof are supplied to the first and second chamber portions, respectively.

3. An apparatus according to claim 1 wherein the cigarette paper wrapper is provided as a roll of paper wrapper having regularly repeating contiguous first and second bands, each band having a defined area and the first band and the second band having different values of a common property, and the sampling device is further configured such that the sampling area is smaller than the respective defined areas of the first and second bands.

4. An apparatus according to claim 3 further comprising an advancement device configured to selectively advance the paper wrapper from the roll and through the sampling device.

5. An apparatus according to claim 4 further comprising a sensor operably engaged with the advancement device and configured to be capable of directing the advancement device to selectively stop the advancement of the paper wrapper through the sampling device such that only one of the first and second bands spans the sampling area.

6. An apparatus according to claim 5 further comprising a sensor operably engaged with at least the analyzer device and configured to direct the analyzer device to determine the amount of the detectable gas in the resultant gas flow at least when the advancement of the paper wrapper through the sampling device is stopped and only one of the first and second bands spans the sampling area.

7. An apparatus according to claim 1 wherein the analyzer device is further configured to be capable of determining a diffusion coefficient of the cigarette paper wrapper with respect to the detectable gas.

8. An apparatus according to claim 1 wherein the carrier gas is a substantially inert gas.

9. An apparatus according to claim 1 wherein the detectable gas is substantially harmless and capable of being released to atmosphere from the second chamber portion.

10. An apparatus according to claim 1 wherein the analyzer device is further configured to determine when the amount of the detectable gas in the resultant gas flow reaches an equilibrium.

11. A method of measuring a property of a cigarette paper wrapper, said method comprising:

receiving a cigarette paper wrapper in a sampling device defining a first chamber portion and a corresponding second chamber portion, the first and second chamber portions engaging at and defining a sampling area, the sampling device being configured to receive the cigarette paper wrapper such that the cigarette paper wrapper spans the sampling area and separates the first chamber portion from the second chamber portion;

supplying a regulated flow of a carrier gas to the first chamber portion;

supplying a regulated flow of a detectable gas to the second chamber portion;

receiving a resultant gas flow at an analyzer device in communication with the first chamber portion, the resultant gas flow including the carrier gas and any of the detectable gas entering the first chamber portion through the cigarette paper wrapper; and

determining, with the analyzer device, an amount of the detectable gas in the resultant gas flow so as to thereby determine a property of the cigarette paper wrapper.

12. A method according to claim 11 further comprising regulating the flows of the carrier gas and the detectable gas with a mass flow meter operably engaged between each of the first and second gas sources and the first and second chamber portions, respectively, such that substantially equal mass flows of the carrier and detectable gases are supplied to the first and second chamber portions, respectively.

13. A method according to claim 11 further comprising supplying the cigarette paper wrapper as a roll of paper wrapper having regularly repeating contiguous first and second bands, each band having a defined area and the first band and the second band having different values of a common property.

14. A method according to claim 13 wherein receiving the cigarette paper wrapper in the sampling device further comprises receiving the cigarette paper wrapper in a sampling device having a sampling area is smaller than the respective defined areas of the first and second bands.

15. A method according to claim 13 further comprising selectively advancing the paper wrapper from the roll and through the sampling device with an advancement device.

16. A method according to claim 15 further comprising directing the advancement device to selectively stop the advancement of the paper wrapper through the sampling device, with a sensor operably engaged with the advancement device, such that only one of the first and second bands spans the sampling area.

17. A method according to claim 16 further comprising directing the analyzer device to determine the amount of the detectable gas in the resultant gas flow, with a sensor operably engaged with at least the analyzer device, at least when the advancement of the paper wrapper through the sampling device is stopped and only one of the first and second bands spans the sampling area.

18. A method according to claim 11 wherein determining an amount of the detectable gas in the resultant gas flow further comprises determining an amount of the detectable gas in the resultant gas flow so as to determine a diffusion coefficient of the cigarette paper wrapper with respect to the detectable gas.

19. A method according to claim 11 wherein supplying a regulated flow of a carrier gas further comprises supplying a regulated flow of a substantially inert gas.

20. A method according to claim 11 wherein supplying a regulated flow of a detectable gas further comprises supplying a regulated flow of a substantially harmless gas capable of being released to atmosphere from the second chamber portion.

21. A method according to claim 11 wherein determining an amount of the detectable gas in the resultant gas flow further comprises determining an amount of the detectable gas in the resultant gas flow when the amount of the detectable gas in the resultant gas flow reaches an equilibrium.