GB2127541A - Monitoring sheet material - Google Patents
Monitoring sheet material Download PDFInfo
- Publication number
- GB2127541A GB2127541A GB08325128A GB8325128A GB2127541A GB 2127541 A GB2127541 A GB 2127541A GB 08325128 A GB08325128 A GB 08325128A GB 8325128 A GB8325128 A GB 8325128A GB 2127541 A GB2127541 A GB 2127541A
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- GB
- United Kingdom
- Prior art keywords
- infra red
- additive
- constituent
- citrate
- wavelength
- Prior art date
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- Granted
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- 239000000463 material Substances 0.000 title claims abstract description 29
- 238000012544 monitoring process Methods 0.000 title claims description 14
- 239000000654 additive Substances 0.000 claims abstract description 32
- 230000000996 additive effect Effects 0.000 claims abstract description 27
- 239000000470 constituent Substances 0.000 claims abstract description 22
- 235000019504 cigarettes Nutrition 0.000 claims abstract description 16
- 238000002835 absorbance Methods 0.000 claims abstract description 13
- 230000003595 spectral effect Effects 0.000 claims abstract description 12
- 238000002329 infrared spectrum Methods 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 37
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 18
- 230000003287 optical effect Effects 0.000 claims description 16
- 150000001768 cations Chemical class 0.000 claims description 11
- 239000001508 potassium citrate Substances 0.000 claims description 10
- 235000011082 potassium citrates Nutrition 0.000 claims description 10
- 239000001509 sodium citrate Substances 0.000 claims description 10
- QEEAPRPFLLJWCF-UHFFFAOYSA-K potassium citrate (anhydrous) Chemical compound [K+].[K+].[K+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O QEEAPRPFLLJWCF-UHFFFAOYSA-K 0.000 claims description 9
- 229960002635 potassium citrate Drugs 0.000 claims description 8
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 claims description 8
- 238000010521 absorption reaction Methods 0.000 claims description 7
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 6
- 150000001450 anions Chemical class 0.000 claims description 5
- 238000003909 pattern recognition Methods 0.000 claims description 2
- 238000011481 absorbance measurement Methods 0.000 abstract 1
- KRKNYBCHXYNGOX-UHFFFAOYSA-K Citrate Chemical compound [O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O KRKNYBCHXYNGOX-UHFFFAOYSA-K 0.000 description 35
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 27
- 229910052708 sodium Inorganic materials 0.000 description 23
- 239000011734 sodium Substances 0.000 description 21
- 238000004458 analytical method Methods 0.000 description 20
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 15
- 229910052700 potassium Inorganic materials 0.000 description 15
- 235000011083 sodium citrates Nutrition 0.000 description 8
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 7
- 230000009102 absorption Effects 0.000 description 6
- 150000001860 citric acid derivatives Chemical class 0.000 description 6
- 229910021532 Calcite Inorganic materials 0.000 description 5
- FNAQSUUGMSOBHW-UHFFFAOYSA-H calcium citrate Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O.[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O FNAQSUUGMSOBHW-UHFFFAOYSA-H 0.000 description 5
- 239000001354 calcium citrate Substances 0.000 description 5
- 239000001913 cellulose Substances 0.000 description 5
- 229920002678 cellulose Polymers 0.000 description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 4
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 4
- 239000011159 matrix material Substances 0.000 description 4
- 229960003975 potassium Drugs 0.000 description 4
- 235000013337 tricalcium citrate Nutrition 0.000 description 4
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 3
- 238000005452 bending Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000011591 potassium Substances 0.000 description 3
- 238000012827 research and development Methods 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 238000004448 titration Methods 0.000 description 3
- 238000002479 acid--base titration Methods 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000004590 computer program Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 2
- 239000013074 reference sample Substances 0.000 description 2
- QNRATNLHPGXHMA-XZHTYLCXSA-N (r)-(6-ethoxyquinolin-4-yl)-[(2s,4s,5r)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]methanol;hydrochloride Chemical compound Cl.C([C@H]([C@H](C1)CC)C2)CN1[C@@H]2[C@H](O)C1=CC=NC2=CC=C(OCC)C=C21 QNRATNLHPGXHMA-XZHTYLCXSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 108010023321 Factor VII Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 241000208125 Nicotiana Species 0.000 description 1
- 235000002637 Nicotiana tabacum Nutrition 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 235000011001 calcium citrates Nutrition 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 235000015165 citric acid Nutrition 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- BNIILDVGGAEEIG-UHFFFAOYSA-L disodium hydrogen phosphate Chemical compound [Na+].[Na+].OP([O-])([O-])=O BNIILDVGGAEEIG-UHFFFAOYSA-L 0.000 description 1
- 229910000397 disodium phosphate Inorganic materials 0.000 description 1
- 235000019800 disodium phosphate Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000008246 gaseous mixture Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 159000000001 potassium salts Chemical class 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000013102 re-test Methods 0.000 description 1
- 238000000611 regression analysis Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000000391 smoking effect Effects 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- 239000008247 solid mixture Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- -1 that is Substances 0.000 description 1
- 238000002411 thermogravimetry Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3563—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing solids; Preparation of samples therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/314—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/86—Investigating moving sheets
Abstract
The concentration of a selected additive in a web of sheet material is determined by measuring the infrared absorbance at first and second wavelengths at which the absorbance of the additive is respectively a maximum and a minimum and finding the difference of the absorbance measurements. Inorganic constituents of cigarette paper are identified and monitored by scanning a region of the infra red spectrum of the paper, computing first and second order derivatives of the scan, comparing the first and second order derivatives by a best fit comparison with reference spectral data, and computing concentrations in the paper of the identified inorganic constituents.
Description
SPECIFICATION
Improvements in or relating to monitoring sheet material
This invention relates to improvements in or relating to the monitoring of constitutents of sheet material, in particular the on-line monitoring of additive constituents of cigarette paper.
It is customary in research and development work in the tobacco industry to measure a number of cigarette paper additives such as calcium carbonate, sodium, potassium, magnesium and mixed sodium and potassium citrates, and monammonium and disodium phosphate. It is for instance commonplace in research and development experiments to analyse paper before making and before smoking in order to minimize retests.
Calcium carbonate is a filler and affects air permeablity and burn rate of cigarette paper, while citrates affect burn rate and phosphates affect ash characteristics. In many research and development applications values of citrate and carbonate are among the most requested analytical data.
Carbonate is currently analysed by acid/base titration or carbonate electrode. Citrate is analysed by pyridine/acetic anhydride reaction or by using permanganate titration or metal analysis methods. Most methods thus measure the anion only and additive weight percentage is calculated using assumed cations.
It is seen that there is a need for a rapid automated system for paper additives analysis with immediate feedback of results and portability for siting in areas where fast data feedback can be used most effectively.
According to a first aspect of the present invention there is provided a method of monitoring online the concentration of a selected additive in a web of sheet material comprising selecting a first wavelength at which the infra red absorbance of the additive is at a maximum, selecting a second wavelength at which the infra red absorbance of the additive is at a minimum, measuring the infra red optical density of the material at the first wavelength and generating a first signal indicative of the optical density at the first wavelength, measuring the infra red optical density of the material at the second wavelength and generating a second signal indicative of the optical density at the second wavelength, determining the difference between the first and second signals and computing from said difference the concentration of the additive in the material.
According to a second aspect of the present invention there is provided a method of identifying and monitoring a constituent in a material comprising selecting and scanning a region of the infra red spectrum of the material, computing first and second order derivatives of the scan, comparing the first and second order derivatives by a best fit comparison with reference infra red spectral data of known constituents thereby identifying said constituent and determining its concentration in the material.
According to a third aspect of the present invention there is provided an apparatus for monitoring on-line the concentration of a selected additive in a web of sheet material, the apparatus comprising in combination means for measuring the optical densities of the additive at first and second selected wavelengths at which the infra red absorbance of the additive is respectively at a maximum and a minimum, means for generating first and second signals corresponding to said optical densities, means for determining the difference between the first and second signals, and means for computing from said difference the concentration of the additive in the material.
According to a fourth aspect of the present invention there is provided an apparatus for identifying and monitoring a selected constituent of a material, the apparatus comprising in combination means for scanning a selected region of the infra red spectrum, and means to compute first and second derivatives of the scan, to compare said first and second order derivatives by a best fit comparison with reference infra red spectral data, and means to determine therefrom the concentration of said constituent in the material.
The invention will now be described by way of example only with reference to the accompanying drawings, in which Figures 1-4 are flow charts, as follows.
The method of monitoring according to the invention is applied to cigarette paper analysis as a series of operations in which the additive anions are determined by their characteristic fundamental infra red absorptions, and the cation component, or the physical structure (e.g. crystalline structure), of the additive is identified by complex pattern recognition of the spectral fine structure. The anion is then measured by the method of the invention and the additive weight percentage is calculated with reference to the identified cation. The sequential steps and specific instructions to the spectrometer are processed automatically by an interfaced computer, which also interprets the spectral data and outputs the desired information on the number of additives, their percentage loading and, where appropriate, their respective physical structures.
Preliminary tests indicated that the citrate and carbonate ions gave characterisic peaks in the midinfra red region of the spectrum which were reasonably free from interference by other paper constituents. A quantitative infra red analyser, the Miran 80 (Trade Mark), was used as a central unit for analysis of cigarette paper additives in the examples.
The Miran 80 is a single beam infra red spectrometer with a spectral range of 2.5 to14.5 microns controlled by a dedicated microprocessor; (1 micron = 0.000001 m and is indicated in the drawings by the Greek letter "mu"). The instrument can be used qualitatively linked to a recorder to provide analog infra red scans, or digital scans using the inbuilt printer. This particular instrument is able to analyse up to a maximum of 11 components directly from liquid, solid, or gaseous mixtures, without the necessity for prior separation before analysis.
Peak maxima of the relevant infra red absorbances are selected from the literature and by running short digital scans over the areas of interest in the infra red spectrum of the mixture. The wavelengths of these peak maxima are then stored in the microprocessor together with a reference wavelength (i.e. a point in the spectrum where little or no absorbance occurs). The spectrometer measures optical densities at each of these wavelengths and converts them via a programmed matrix to concentration.
Parameters such as analysis time per wavelength and delay between repeat analysis may be varied to give the optimum optical density reading.
Calibration is carried out by measuring the optical density at the selected wavelengths of sampies of known concentration. An external computer program then converts the values of optical density and concentration to a matrix suitable for the Miran 80, using linear matrix algebra. It is convenient to use a program that can give either zero or non-zero intercepts on request.
When the matrix and parameters have been entered into the microprocessor, analyses may be carried out automatically at the press of a button.
Paper from a single cigarette may simply be clamped in a sample holder and exposed to the beam of light from the spectrometer. Alternatively, large reels of paper may be run through the light path while the instrument is analysing.
EXAMPLE 1
Determination of calcium carbonate.
Calcium carbonate occurs in two crystalline forms, namely aragonite (rhombic), calcite (ditrigonal), both of which are used in cigarette paper manufacture. Their main infra red spectral maxima of 6.90 and 11.77 microns, for aragonite, and 7.14 and 1 1.54 microns for calcite are due to doubly degenerate asymmetric stretching and out-of-plane bending of the carbonate ion respectively.
The mid-infra red spectrum of cigarette paper is dominated by its major constituent, that is, cellulose.
Its variable absorption at 6-8 microns precludes using the major carbonate peaks of 6.90 and 7.14 microns, so consequently the chosen analytical wavelength for paper analysis is the out-of-plane bending at 1 1.77 (aragonite) or 1 1.54 microns (calcite). A short digital scan between 11.4 and 1 1.8 microns will show the crystalline form present if the source is unknown. The reference wavelength used is 11.00 microns which is the minimum between a cellulose absorption and the out-of-plane bending of the carbonate ion, and is independent of crystal structure.
The zero and gain of the spectrometer were set prior to calibration using a chalk-free paper. The spectrometer was then calibrated using three papers previously analysed by acid/base titration and covering the range 5.9 to 29.9% by weight aragonite in approximately equal steps.
Table 1 shows the carbonate content of various papers obtained by the analysis technique of the invention and compared with analytical results obtained by a reference titrimetric procedure. Where a substantial anomaly was noticed the paper concerned was analysed again using a thermogravimetric technique. Such anomalies are believed to be due to the fact that reference values were determined on averages of approximately 2 meter lengths of paper, whereas infra red data and data obtained by thermogravimetric techniques were determined on 0.01 m lengths of paper.
EXAMPLE 2
Determination of citrate ion.
Cellulose and carbonate absorptions combine to give relatively few infra red transparent "windows" for citrate measurement, and there is only one peak in the citrate ion infra red spectrum that stands out from the normal paper background at low levels. This is at 6.352 microns and is due to asymmetric stretch of the strongly coupled carbon and oxygens of the acid functional groups. The absorption peak is dependent on the action associated with the citrate ion and is greater for a monovalent cation than for a divalent cation at the same level of citrate ion. The enhancement follows a linear relationship and so may be compensated for in the off line matrix program. Two wavelengths are required for the anaylsis. The analytical wavelength at 6.352 microns, and the reference wavelength, a minimum between cellulose and citrate absorbance, at 5.800 microns.
The zero and gain of the spectrometer were set prior to calibration using a non-citrate pauper. The spectrometer was then calibrated using two papers containing 2.08 and 3.95% by weight citrate ion, added as citric acid and therefore present in the paper as calcium citrate. The citrate levels had previously been determined using the pyridine/acetic ahydride reaction.
Table 2 shows the citrate content of various papers obtained by the analysis technique of the invention and compared with analytical results obtained by a reference titrimetric procedure.
A regression analysis carried out on the data of Table 2 gave the following equation:
spectrometer = 1.2728 x titrimetric method + 0.018
That is, the citrate absorbance for sodium and potassium salts is 1.273 times greater than that of
calcium citrate (the product of adding citric acid to chalk loaded paper, in samples 21 and 22).
The enhancement effect of monovalent cations was confirmed by standard additions of potassium citrate, sodium citrate and citric acid to base paper. Additions were calculated to give 10% citrate ion concentrations on the paper. Results are given in Table 3, where measured citrate refers to
measurements made by the method of the invention on the spectrometer, and corrected citrates are those values divided by 1.273.
Each citrate measurement made by the method of the invention using the spectrometer was taken over approximately 0.004 m paper, the width of the infra red incident beam. This gives the technique sufficient discrimination to measure short or long term distribution trends.
It is found by the method of the invention that cigarette paper can be analysed for carbonate and citrate content rapidly, automatically, and on line, without destroying or otherwise harming the paper.
An outline of the controlling computer program is described as follows, first in general terms, and then with specific reference to the flow charts shown in Figures 1 to 4.
The operator is presented with the choice of a full additives search and analysis or specific analysis of a known additive. Selection of the search routine will instruct the spectrometer to scan aragonite and calcite absorptions, identify the type, and to analyze and report the percentage loading.
The spectrometer is then instructed by the computer to scan the main citrate peak and, if citrate is detected, to measure the percentage citrate and then to scan the spectral region between 8.0 and 9.0 microns in 20 equal increments. These data are used to compute second derivatives at 8.70, 8.75 and 8.82 microns by a best fit technique using the central-difference formula given in "Interpolation and
Allied Tables", HMSO,1956, using four observations either side of each point. The spectra of pure sodium, potassium and calcium citrates can be characterised by a minor absorbance peak at 8.70 microns for sodium citrate, 8.75 microns for potassium citrate, and 8.82 microns for calcium citrate. In cigarette paper they occur as inflexions on a major peak at 8.50 microns but are resolved by the second derivative analysis described above.The presence of sodium citrate is confirmed by a minimum second derivative at 8.70 microns, potassium citrate is confirmed by a minimum second derivative at 8.75 microns and calcium citrate is confirmed by a minimum value at 8.82 microns. Similarly, the presence of mixed citrates is confirmed by minima at both 8.70 and 8.75 microns. From these identifications of the cation associated with citrate, the additive loading is computed and reported.
Selection of the analyse option requests the operator to enter the full identity of the additive. The spectrometer is then instructed to scan the appropriate fraction of the infra red spectrum; spectral values are converted to a percentage loading and final values are reported.
The use of first and second derivatives of the scan is a sensitive technique for identifying and measuring peaks that are close to and masked by another peak or peaks.
The invention is now described with specific reference to the flow charts of Figures 1 to 4.
With reference to Figure 1 the user is invited to choose either the search or the analyse option.
Figure 1 then proceeds with the search option by carrying out the "carbonate process" which is shown ir more detail in Figure 3.
In the carbonate process of Figure 3 the computer instructs the spectrometer to measure the peaks at 11.0, 11.77, and 11.54 microns. The heights of the peaks at these wavelengths are A, B and C, respectively. The computer then works out the percentages D and E of aragonite and calcite respectively from the formulae, D=(B-A) x factor 1 E=(C-A) x factor 2 where factor 1 and factor 2 are constants peculiar to the apparatus and which have to be determined by calibration.
Having determined the carbonate content by the process of Figure 3 we now return to Figure 1 and proceed with the "citrate process" which is shown in more detail in Figure 4.
In the citrate process of Figure 4 the computer instructs the spectrometer to measure the peaks at 6.352 and 5.800 microns. The heights of these peaks at these wavelengths are F and G respectively.
The computer then works out the percentage H of the citrate ion from the formula, H=(F-G) xfactor3 where factor 3 is a constant peculiar to the apparatus and which has to be determined by calibration.
Having determined the citrate ion content by the process of Figure 4 we return yet again to Figure 1 and proceed with the process of determining the ion to be associated with the citrate ion, i.e. sodium, potassium, sodium/potassium mixture, calcium or hydrogen (i.e. citric acid).
This is done by instructing the spectrometer to drive to 8.0 microns and to measure the peaks over the range 8-9 microns in 0.5 micron increments. The results are tested in the manner described above for the best statistical fit with the appropriate ion. If the best fit is with sodium we multiply H by factor 4
to obtain J, the percentage of sodium citrate. Likewise, if the best fit is with any of the three other
possibilities we multiply H by any one of factors 5-7 to obtain the respective percentage K, L or M of
potassium citrate, mixed citrates, or citric acid, as appropriate.
Factors 4-7 are the ratios for converting the percentage of citrate ion to sodium citrate,
potassium citrate, mixed citrates, or citric acid respectively.
The values of factors 4-7 are,
factor 4 = 1.366
factor 5=1.621 factor 6 = 1.493
factor 7 = 1.0158
Figure 2 is similar in detail to Figure 1 but illustrates instead the option of analysing for a single substance, i.e. citrate or carbonate, and if citrate, then the choice of sodium citrate, potassium citrate, mixed citrates, or citric acid. The "carbonate" and "citrate" processes are the same as described with reference to Figures 3 and 4 respectively, and factors 4-7 have the same values as listed above.
It will be understood that the technique of implementing the flow charts shown in Figures 1 to 4 on a computer is well known in the computer art and need not be described in this specification.
The method of the invention is particularly useful for analyzing the constituents of cigarette paper because cigarette paper is characterised by an even thickness and smooth surface. The method of the invention may clearly be adapted to other papers having similar properties such as banknote paper or the like.
The method of the invention may be used to identify or to measure other constituents of cigarette paper on line, such as the identification of the form of mineral chalk or the cation associated with citrate.
The form or source of the cellulose constituent of the paper may also be characterised.
The invention may also be used to analyse plug or plugwrap constituents or to analyse flavours.
The invention may also be used in paper making process control.
TABLE 1
Reference
Sample No. Titration Spectrometer Thermogravimetry
1 28.5 28.4
2 35.0 37.8 37.5
3 11.4 12.1
4 19.4 18.9
5 22.7 19.7 20.5
6 15.9 14.1 14.2
7 54.8 45.5 50.0
8 27.3 26.3
9 25.0 22.6 24.7
10 25.6 22.3 25.6
11 23.3 12.1 12.8
12 27.4 27.5
13 26.1 22.7 25.0
14 27.2 27.2
15 27.8 28.6
TABLE 2
Reference
Sample No. Titration Spectrometer Type of citrate
1 0.32 0.41 100% K 2 0.71 0.97 100% K
3 1.11 1.34 100% K
4 1.50 1.92 100% K
5 0.42 0.41 100% Na
6 0.88 1.28 100% Na
7 1.33 1.99 100% Na
8 1.65 2.12 100% Na
9 0,37 0.68 25% Na:75% K
10 0.38 0.63 50% Na:50% K
11 0.40 0.58 75% Na:25% K
12 0.74 0.90 25% Na:75% K
13 0.78 1.05 50% Na:50% K
14 0.82 1.20 75% Na:25% K
15 1.13 1.06 25% Na:75% K
16 1.16 1.55 50%Na:50%K
17 1.21 1.64 75% Na:25% K
18 1.53 2.05 25% Na:75% K
19 1.64 1.87 50% Na:50% K
20 1.68 1.95 75%Na:25%K 21 2.15 2.15 100% Citric acid
22 2.28 2.31 100% Citric acid
TABLE 3
Cation Measured citrate Corrected citrate
K+ 12.0 9.4
Na+ 12.9 10.1
H+(Ca) 9.8
Claims (9)
1. A method of monitoring on-line the concentration of a selected additive in a web of sheet material comprising selecting a first wavelength at which the infra red absorbance of the additive is at a maximum, selecting a second wavelength at which the infra red absorbance of the additive is at a minimum, measuring the infra red optical density of the material at the first wavelength and generating a first signal indicative of the optical density at the first wavelength, measuring the infra red optical density of the material at the second wavelength and generating a second signal indicative of the optical density at the second wavelength, determining the difference between the first and second signals and computing from said difference the concentration of the additive in the material.
2. A method as claimed in claim 1 wherein the sheet material is cigarette paper.
3. A method as claimed in claim 1 or 2 wherein the selected additive is selected from the group consisting of calcium carbonate, sodium citrate, and potassium citrate.
4. A method of idenfiying and monitoring a constituent in a material comprising selecting and scanning a region of the infra red spectrum of the material, computing first and second order derivatives of the scan, comparing the first and second order derivatives by a best fit comparison with reference infra red spectral data of known constituents thereby identifying said constituent and determining its concentration in the material.
5. A method as claimed in claim 4 in which the constituent comprises an anion and a cation, wherein the anion is determined by its characteristic fundamental infra red absorption and the cation is determined by complex pattern recognition of the infra red spectral fine structure.
6. A method as claimed in either of claims 4 and 5 in which the material is cigarette paper and the constituent is selected from the group consisting of calcium carbonate, sodium citrate, and potassium citrate.
7. A method of identifying and monitoring a constituent in a material substantially as hereinbefore described with reference to the Examples and the accompanying Figures 1 to 4.
8. An apparatus for monitoring on-line the concentration of a selected additive in a web of sheet material, the apparatus comprising in combination means for measuring the optical densities of the additive at first and second selected wavelengths at which the infra red absorbance of the additive is respectively at a maximum and a minimum, means for generating first and second signals corresponding to said optical densities, means for determining the difference the first and second signals. and means for computing from said difference the concentration of the additive in the material.
9. An apparatus for identifying and monitoring a selected constituent of a material, the apparatus comprising in combination means for scanning a selected region of the infra red spectrum, and means to compare said first and second order derivatives by a best fit comparison with reference infra red spectral data, and means to determine therefrom the concentration of said constituent in the material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08325128A GB2127541B (en) | 1982-09-27 | 1983-09-20 | Monitoring sheet material |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8227507 | 1982-09-27 | ||
| GB08325128A GB2127541B (en) | 1982-09-27 | 1983-09-20 | Monitoring sheet material |
| CA000455039A CA1221457A (en) | 1982-09-27 | 1984-05-24 | Monitoring sheet material |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8325128D0 GB8325128D0 (en) | 1983-10-19 |
| GB2127541A true GB2127541A (en) | 1984-04-11 |
| GB2127541B GB2127541B (en) | 1986-08-20 |
Family
ID=36685702
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08325128A Expired GB2127541B (en) | 1982-09-27 | 1983-09-20 | Monitoring sheet material |
| GB08524773A Expired GB2163552B (en) | 1982-09-27 | 1985-10-08 | Improvements in or relating to monitoring sheet material |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08524773A Expired GB2163552B (en) | 1982-09-27 | 1985-10-08 | Improvements in or relating to monitoring sheet material |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4718026A (en) |
| CA (1) | CA1221457A (en) |
| GB (2) | GB2127541B (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2147413A (en) * | 1983-09-28 | 1985-05-09 | Sentrol Systems Ltd | Infrared analysis |
| EP0186620A2 (en) * | 1984-12-24 | 1986-07-02 | Mitsubishi Jukogyo Kabushiki Kaisha | Method of controlling film thickness of mixture liquid layer of oil material and water in printing machines |
| US4631408A (en) * | 1984-09-24 | 1986-12-23 | Kollmorgen Technologies Corporation | Method of simultaneously determining gauge and orientation of polymer films |
| EP0332018A2 (en) * | 1988-03-10 | 1989-09-13 | Abb Process Automation Inc. | Clay sensor |
| WO1998036264A1 (en) * | 1997-02-13 | 1998-08-20 | Valmet Automation Inc. | Method for measuring the components of a coating on a moving base material |
| US5914490A (en) * | 1997-02-13 | 1999-06-22 | Valmet Automatic, Inc. | Procedure for measuring the components of a coating on a moving base material |
| WO1999041590A1 (en) * | 1998-02-12 | 1999-08-19 | Neles Paper Automation Oy | Method and device for measuring the amount of coating on a moving substrate |
| GB2533589A (en) * | 2014-12-22 | 2016-06-29 | Ndc Infrared Eng Ltd | Measurement of porous film |
| CN106770011A (en) * | 2016-12-26 | 2017-05-31 | 重庆中烟工业有限责任公司 | A kind of cigarette paper positive and negative discrimination method and system |
| CN106770012A (en) * | 2016-12-26 | 2017-05-31 | 重庆中烟工业有限责任公司 | A kind of cigarette paper positive and negative discrimination method and system |
| CN106841091A (en) * | 2016-12-26 | 2017-06-13 | 重庆中烟工业有限责任公司 | A kind of cigarette paper positive and negative discrimination method and system |
| CN107884360A (en) * | 2017-10-24 | 2018-04-06 | 浙江中烟工业有限责任公司 | A kind of cigarette paper combustion adjuvant detection method |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5104485A (en) * | 1988-05-31 | 1992-04-14 | Hercules Incorporated | Method of measuring non-aqueous constituents in a pulp slurry of a water/cellulose matrix |
| US5250811A (en) * | 1991-12-20 | 1993-10-05 | Eastman Kodak Company | Method for determining compositional information of a multilayer web |
| US5541413A (en) * | 1992-04-24 | 1996-07-30 | Thiokol Corporation | Acousto-optic tunable filter-based surface scanning system and process |
| US5406082A (en) * | 1992-04-24 | 1995-04-11 | Thiokol Corporation | Surface inspection and characterization system and process |
| DE4328357C2 (en) * | 1993-08-24 | 1995-08-17 | Herberts Gmbh | Process for the quantitative determination of the non-volatile components of coating agents or coating agent components different from pigments and fillers |
| US6075882A (en) * | 1997-06-18 | 2000-06-13 | Philip Morris Incorporated | System and method for optically inspecting cigarettes by detecting the lengths of cigarette sections |
| US6020969A (en) * | 1997-07-11 | 2000-02-01 | Philip Morris Incorporated | Cigarette making machine including band inspection |
| US6198537B1 (en) | 1997-07-11 | 2001-03-06 | Philip Morris Incorporated | Optical inspection system for the manufacture of banded cigarette paper |
| US5966218A (en) * | 1997-07-11 | 1999-10-12 | Philip Morris Incorporated | Bobbin optical inspection system |
| GB2367616B (en) * | 1999-06-23 | 2004-06-16 | Patrick Toomey | Water detection and source identification methods for structures using electromagnetic radiation spectroscopy |
| CN102507483B (en) * | 2011-10-12 | 2013-04-10 | 云南省烟草质量监督检测站 | Method for determining content of calcium carbonate in cigarette paper |
| CN104101572A (en) * | 2013-04-11 | 2014-10-15 | 江苏中烟工业有限责任公司徐州卷烟厂 | Method for detecting content of heavy metals in inner liner for cigarette |
| IT201800003041A1 (en) * | 2018-02-26 | 2019-08-26 | Gd Spa | Method and unit for processing a strip of the tobacco industry |
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| GB1039746A (en) * | 1962-04-06 | 1966-08-24 | Bayer Ag | An apparatus for measuring the water content of photographic layers |
| GB1069910A (en) * | 1963-10-01 | 1967-05-24 | Kalle Ag | Method of and apparatus for continuously measuring applied coatings |
| GB1126841A (en) * | 1964-09-25 | 1968-09-11 | Kollmorgen Corp | Improvements in photometric method and apparatus |
| GB2008745A (en) * | 1977-11-03 | 1979-06-06 | Anacon Instr Ltd | Spectrophotometer |
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| US3793524A (en) * | 1972-09-05 | 1974-02-19 | Measurex Corp | Apparatus for measuring a characteristic of sheet materials |
| US3851175A (en) * | 1972-10-27 | 1974-11-26 | Measurex Corp | Moisture gauge with opacity type compensation |
| JPS54131985A (en) * | 1978-04-05 | 1979-10-13 | Hitachi Ltd | Two-wavelength spectrophotometer |
| GB2020009B (en) * | 1978-04-08 | 1982-12-01 | Bodenseewerk Perkin Elmer Co | Apparatus for determining the concentration of components of a sample |
| US4363968A (en) * | 1979-07-19 | 1982-12-14 | Owens-Corning Fiberglas Corporation | Method and apparatus for determining the binder content in a fibrous mat |
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1983
- 1983-09-20 GB GB08325128A patent/GB2127541B/en not_active Expired
-
1984
- 1984-05-24 CA CA000455039A patent/CA1221457A/en not_active Expired
- 1984-05-25 US US06/614,171 patent/US4718026A/en not_active Expired - Fee Related
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1985
- 1985-10-08 GB GB08524773A patent/GB2163552B/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1039746A (en) * | 1962-04-06 | 1966-08-24 | Bayer Ag | An apparatus for measuring the water content of photographic layers |
| GB1069910A (en) * | 1963-10-01 | 1967-05-24 | Kalle Ag | Method of and apparatus for continuously measuring applied coatings |
| GB1126841A (en) * | 1964-09-25 | 1968-09-11 | Kollmorgen Corp | Improvements in photometric method and apparatus |
| GB2008745A (en) * | 1977-11-03 | 1979-06-06 | Anacon Instr Ltd | Spectrophotometer |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2147413A (en) * | 1983-09-28 | 1985-05-09 | Sentrol Systems Ltd | Infrared analysis |
| US4631408A (en) * | 1984-09-24 | 1986-12-23 | Kollmorgen Technologies Corporation | Method of simultaneously determining gauge and orientation of polymer films |
| EP0186620A2 (en) * | 1984-12-24 | 1986-07-02 | Mitsubishi Jukogyo Kabushiki Kaisha | Method of controlling film thickness of mixture liquid layer of oil material and water in printing machines |
| EP0186620A3 (en) * | 1984-12-24 | 1988-06-08 | Mitsubishi Jukogyo Kabushiki Kaisha | Method of controlling film thickness of mixture liquid layer of oil material and water in printer |
| EP0332018A2 (en) * | 1988-03-10 | 1989-09-13 | Abb Process Automation Inc. | Clay sensor |
| EP0332018A3 (en) * | 1988-03-10 | 1991-07-24 | Abb Process Automation Inc. | Clay sensor |
| WO1998036264A1 (en) * | 1997-02-13 | 1998-08-20 | Valmet Automation Inc. | Method for measuring the components of a coating on a moving base material |
| US5914490A (en) * | 1997-02-13 | 1999-06-22 | Valmet Automatic, Inc. | Procedure for measuring the components of a coating on a moving base material |
| WO1999041590A1 (en) * | 1998-02-12 | 1999-08-19 | Neles Paper Automation Oy | Method and device for measuring the amount of coating on a moving substrate |
| GB2533589A (en) * | 2014-12-22 | 2016-06-29 | Ndc Infrared Eng Ltd | Measurement of porous film |
| US10161863B2 (en) | 2014-12-22 | 2018-12-25 | Ndc Technologies Limited | Measurement of porous film |
| CN106770011A (en) * | 2016-12-26 | 2017-05-31 | 重庆中烟工业有限责任公司 | A kind of cigarette paper positive and negative discrimination method and system |
| CN106770012A (en) * | 2016-12-26 | 2017-05-31 | 重庆中烟工业有限责任公司 | A kind of cigarette paper positive and negative discrimination method and system |
| CN106841091A (en) * | 2016-12-26 | 2017-06-13 | 重庆中烟工业有限责任公司 | A kind of cigarette paper positive and negative discrimination method and system |
| CN107884360A (en) * | 2017-10-24 | 2018-04-06 | 浙江中烟工业有限责任公司 | A kind of cigarette paper combustion adjuvant detection method |
| CN107884360B (en) * | 2017-10-24 | 2020-01-07 | 浙江中烟工业有限责任公司 | Cigarette paper combustion improver detection method |
Also Published As
| Publication number | Publication date |
|---|---|
| CA1221457A (en) | 1987-05-05 |
| GB2127541B (en) | 1986-08-20 |
| GB8524773D0 (en) | 1985-11-13 |
| GB2163552B (en) | 1986-09-24 |
| US4718026A (en) | 1988-01-05 |
| GB2163552A (en) | 1986-02-26 |
| GB8325128D0 (en) | 1983-10-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |