CA2226095A1 - Method of identifying post consumer or post industrial waste carpet utilizing a hand-held infrared spectrometer - Google Patents
Method of identifying post consumer or post industrial waste carpet utilizing a hand-held infrared spectrometer Download PDFInfo
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- CA2226095A1 CA2226095A1 CA002226095A CA2226095A CA2226095A1 CA 2226095 A1 CA2226095 A1 CA 2226095A1 CA 002226095 A CA002226095 A CA 002226095A CA 2226095 A CA2226095 A CA 2226095A CA 2226095 A1 CA2226095 A1 CA 2226095A1
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- 238000000034 method Methods 0.000 title claims abstract description 23
- 239000002440 industrial waste Substances 0.000 title claims abstract description 18
- 230000005855 radiation Effects 0.000 claims abstract description 100
- 239000000463 material Substances 0.000 claims abstract description 44
- 239000002699 waste material Substances 0.000 claims abstract description 39
- 229920002292 Nylon 6 Polymers 0.000 claims abstract description 28
- 229920002302 Nylon 6,6 Polymers 0.000 claims abstract description 22
- 238000001514 detection method Methods 0.000 claims abstract description 19
- 239000004020 conductor Substances 0.000 claims description 26
- 230000003287 optical effect Effects 0.000 claims description 9
- 230000001678 irradiating effect Effects 0.000 claims 7
- 238000001914 filtration Methods 0.000 claims 2
- 239000010817 post-consumer waste Substances 0.000 description 12
- 238000001228 spectrum Methods 0.000 description 12
- 239000000523 sample Substances 0.000 description 11
- 230000003595 spectral effect Effects 0.000 description 8
- -1 Polypropylene Polymers 0.000 description 7
- 230000009102 absorption Effects 0.000 description 7
- 238000010521 absorption reaction Methods 0.000 description 7
- 238000004064 recycling Methods 0.000 description 6
- 239000004743 Polypropylene Substances 0.000 description 5
- 229920000139 polyethylene terephthalate Polymers 0.000 description 5
- 239000005020 polyethylene terephthalate Substances 0.000 description 5
- 229920001155 polypropylene Polymers 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 238000005457 optimization Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 241000894007 species Species 0.000 description 4
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 230000002068 genetic effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 101100400378 Mus musculus Marveld2 gene Proteins 0.000 description 2
- 238000007621 cluster analysis Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 239000012925 reference material Substances 0.000 description 2
- 238000004611 spectroscopical analysis Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- 241000905957 Channa melasoma Species 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 229910020175 SiOH Inorganic materials 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 150000004770 chalcogenides Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
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- 239000000428 dust Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 229930002839 ionone Natural products 0.000 description 1
- 150000002499 ionone derivatives Chemical class 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- 238000012067 mathematical method Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000010187 selection method Methods 0.000 description 1
- SBIBMFFZSBJNJF-UHFFFAOYSA-N selenium;zinc Chemical compound [Se]=[Zn] SBIBMFFZSBJNJF-UHFFFAOYSA-N 0.000 description 1
- 239000013077 target material Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000012780 transparent material Substances 0.000 description 1
- 230000004304 visual acuity Effects 0.000 description 1
- 210000002268 wool Anatomy 0.000 description 1
Classifications
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- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/30—Measuring the intensity of spectral lines directly on the spectrum itself
-
- 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
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
- G01J3/0229—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/02—Mechanical
- G01N2201/022—Casings
- G01N2201/0221—Portable; cableless; compact; hand-held
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/12—Circuits of general importance; Signal processing
- G01N2201/129—Using chemometrical methods
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Spectrometry And Color Measurement (AREA)
Abstract
A method and apparatus for use in the recylcing of post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste utilizes a hand-held portable device utilizing spectroscopic principles to accurately and quickly identify the material of the waste (carpet). The spectrometer envisioned for this task includes an infrared radiation source for illuminating the waste (carpet) sample, a selector for selecting a predetermined number of discrete wavelengths and a detection system to detect reflected radiation within the discrete wavelengths. The selector can be either a plate with a plurality of slots which positionally correspond to locations in a dispersed light beam according to the predetermined discrete wavelengths or a plurality of filters selected to pass the discrete wavelengths. The selection of the discrete wavelengths can either take place before the carpet sample is irradiated or can take place by selecting the discrete wavelengths from reflected radiation.
Description
CA 0222609~ 1997-12-31 W O 97102481 PCT~NL96/00280 LU~ G RECYCLABLE C~URPET ~LATERU~LS USING A HUUNI~HE3LD INFRUIU3D
SPECTRO~lElE3R
BAC~GROUND OF THE lNV~ ION
Field of the Invention The invention relates to a method and apparatus for identifying post consumer or post industrial waste carpet using an infrared (IR) spectrometer, and more particularly to a method of identi~ying post consumer or post industrial waste carpet using a hand-held IR spectrometer having an IR
radiation source which illuminates the post consumer or post industrial waste carpet with IR radiation, a selector for selecting a predetermined number of discrete wavelengths of radiation and an IR detection system for detecting radiation reflected by the post consumer or post industrial waste carpet. The invention also relates to a method and apparatus for identifying Polyamide-6 and/or Polyamide-66 containing material using a hand-held IR-spectrometer enabling sorting of the Polyamides.
De~cription of the Related Art Recycling post consumer or post industrial waste carpet material requires the post consumer or post industrial waste carpet material to be sorted according to the type of face fiber used to manufacture the carpet. Throughout this application, applicants will repeatedly refer to "post consumer waste carpet", which is used by applicants as a generic term encompassing both post consumer waste carpet, post industrial waste carpet and Polyamide-6 and/or Polyamide-66 containing waste streams.
CA 0222609~ 1997-12-31 W O 97/02481 PCTnNL~ r-r Currently, carpets employ ~ace ~ibers produced ~rom materials such as Polyamide-6, Polyamide-66, Polypropylene, Wool, Polyester and blends o~ these component products. For a recycling program to be success~ul, it must be easy to accurately identi~y the type o~ ~ace ~iber used by the carpet.
One method o~ identi~ying carpets is to print a code on the back o~ the carpet. Un~ortunately, although this is the most ~ool-proo~ o~ all possible methods, it requires the carpets to have been marked when manu~actured. There~ore, even i~ marking was started today, this method would not become e~ective ~or approximately 10 years due to the expected li~e o~
the marked carpet. Further, this method may not be satis~actory when used with glued carpets, since the backing o~ glued carpets may be damaged, thus rendering the identi~ication code di~icult to read.
Alternatively, it is possible to identi~y the type o~ carpet by detecting the melting point o~ the ~ace ~iber. This identi~ication method is inadeguate because it is not able to separate streams o~ Polyester and Polyamide-66. Further, blends o~ the various types o~ ~ace ~ibers cannot be distinguished. Devices which utilize the melting point of the carpet material as a distinguishing characteristic are also de~icient in that they generally tend to have a long warm-up time, thus reducing e~iciency, and can be dangerous since they necessarily involve hot components.
A third way to identi~y the type o~ ~ace material used on a particular waste carpet sample is to use a spectroscope. It is well known that various materials can be identi~ied using vibrational spectroscopic technigues like mid-in~rared and near in~rared spectroscopy. In particular, near in~rared spectroscopy is a well known method, e.g. ~or the sorting o~ bottles. IR spectroscopy can be conducted on -CA 0222609~ 1997-12-31 W O 97/02481 PCTnNL96/00280 transparent materials by analyzing radiation passing through the materials, and on substances which are opaque to IR radiation by analyzing the di~use radiation reflected by the material. To con~orm with~ 5 the customary usage in optics, this application will sometimes re~er to IR radiation as "light".
IR spectrometers, ~or both the near-in~rared range (800-2500 nm) and the mid-in~rared range (2500-25000 nm), are o~ten used to identi~y and quanti~y materials on the basis o~ the material characteristics which cause them to absorb or re~lect particular wavelengths. In many cases, these characteristic ~requencies are only slightly dif~erent ~or di~erent materials. It is there~ore important to use a high spectral resolution spectrometer, especially when attempting to distinguish various materials mixed together.
An IR spectrometer generally includes a source which emits radiation in the desired wavelength range and auxiliary optics such as lenses and mirrors to ~orm the radiation into a beam of suitable shape and dimensions and to guide it along a light path. As a rule, all elements that make up the spectrometer are accommodated in an enclosure which preferably is sealed to prevent dust ~rom inter~ering with the components.
The light source is pre~erably placed in a re~lector casing so that the spectrometer can obtain as much light as possible. The light source is pre~erably incorporated in the optical casing, so that light egresses from the spectrometer via an optically transparent window to impinge on the target material.
The transparent window may be, ~or instance, glass or high-guality guartz or may be made of for instance RBr, RC1, ZnSe, RRS~, CaF2 or MgF2 for the mid-in~rared range.
The beam is directed at a site on the CA 0222609~ l997-l2-3l material to be examined. The reflected radiation is then collected, f'ormed to have a desired beam geometry and eventually directed onto a detection system. This detection system normally includes a detector capable of measuring the intensity o~ the incident radiation.
Several detectors which may be used in the near-in~rared range include PbS and InGaAs detectors, and detectors which may be used in the mid-inf'rared range include detectors made ~rom deuterized triglycinesulphate (DTGS).
There are several basic types of IR
spectrometers. Two types o~ IR spectrometers are discussed below. In the f'irst type, discrete wavelengths are selected by passing ref'lected radiation through dif'f'erent f'ilters that are only transparent to a particular wavelength range. In the second type, a beam of reflected IR radiation is dispersed and allowed to impinge on a diode array. Unf'ortunately, diode arrays o~ this nature and having the desired resolving power are very expensive, and selection of' the desired wavelength f'rom the absorbed spectrum must take place in a later phase in the downstream processing equipment, thus increasing the amount of' support electronics necessary to utilize the spectrometer.
The relationship between the intensity and the wavelength of the reflected or transmitted light ~rom a particular material is called the spectrum. The detector is linked to a processing system which converts the detector signals into a spectral ~orm accessible to the user or a computer such as a curve or numerical values.
In general, the mid- and near-infrared spectra of various types o~ ~ibers used in carpets differ signi~icantly. However, t~e spectra of polyamide-6 and polysmide-66 dif er only slightly: the mid-inf'rared spectrum is completely identical and the CA 0222609~ l997-l2-3l W O 97/02481 PCT~NL96/00280 - 5 -near infrared spectra is only slightly different in the 2000-2500 nm spectral range.
The quality of identification obtainable using a given spectroscopic system is expressed as the Mahalonobis-distance (MD), which is the center-to-center distance between the various clusters in relation to the spread within the clusters. For good separation, a minimum MD value of about 6 is required, but ideally the value should be larger than 10.
Unfortunately, although Ghosh and Rogers (Melliand Textilberichte 5, 1988, pages 361-364) indicated that the scanning spectrometer in their system achieved very good MD results for sorting Polyamide-6 and Polyamide-66 ~ibers (MD = 18), the size and price of the scanning spectrometer renders this system largely unsuitable for use in the carpet recycling business.
Ghosh and Roogers also demonstrated that it is possible to identify nylon 6 and nylon 66 fibers used for carpet production using a Bran&Luebbe (Formerly Technicon) InfraAlyzer 500C, with a combination of 3 filters, (2250, 2270 and 2310 nm).
These reported results are also deceiving, in that used carpets have different fiber materials than new carpets due to wear and contamination, thus complicating identification. For example, using these same 3 ~ilters on a sample o~ 113 post consumer carpet waste samples, applicants discovered that the obtainable MD ranged between 4 and 1.2, depending on the resolution of the spectrometer. As indicated above, results of this nature are clearly insu~ficient to accurately discriminate between various carpet samples.
Accordingly, it still has not been demonstrated to be possible to distinguish various types of post consumer waste carpet utilizing a cheap, small and portable spectrometer based on selected wavelengths.
CA 0222609~ 1997-12-31 W O97/02481 PCTn~L96/00280 -- 6 --Likewise, although portable inexpensive IR
~ilter-based spectrometers are commercially available ~or task speci~ic applications, such as to determine the moisture content o~ various materials, no one has been able to develop a hand-held spectrometer which is able to satis~actorily distinguish between various types o~ carpet ~ace material so that the spectrometer can be suitably used in recycling post consumer waste carpet.
S~MM~RY OF THE lNv~ ION
One object o~ the invention is to provide a method o~ reliably analyzing post consumer carpet waste using a hand-held IR spectrometer. To do this, the lS invention utilizes a hand-held spectrometer which is capable o~ measuring at a number o~ discrete wavelengths with su~icient resolution.
Two such hand-held spectrometers are envisioned in this respect. The ~irst hand-held spectrometer is capable o~ measuring a number o~
discrete wavelengths with good resolution by utilizing a radiation selector which disperses the radiation and selects discrete wavelengths ~rom the dispersed radiation using a plate provided with openings at locations corresponding to the positions o~ the discrete wavelengths in the dispersed radiation to be selected.
The second hand-held spectrometer is also capable o~ measuring a number o~ discrete wavelengths, but utilizes ~ilters which pass particular selected wavelengths optimal ~or use in the carpet recycling business.
Depending on the application to which the spectrometer will be applied, the spectra in the near-in~rared range or the mid-in~rared range o~ a series of samples are recorded using a high-resolution CA 0222609~ 1997-12-31 W O 97/02481 PCTnNL96100280 spectrometer. These high-resolution spectra are used to determine the combination o~ absorptions at dif~erent wavelengths which yield sufficient in~ormation ~or discriminating one polymer ~rom another. In the case of carpet recycling, ~or instance, one might wish to know i~ a carpet is made of Polypropylene, Polyamide-6, Polyamide- 66 or Polyethylene Terephthalate (PET).
Absorption o~ the detector should be checked against a reference material o~ a known substance.
Suitable reference materials for diffuse reflection in the near-in~rared range include, ~or example, small ceramic plates and small teflon plates.
Absorption is calculated as follows:
AA = l~g(I~(..mple)/IA(r.~.r.nc. mllt~ri~l))~ ... (1) where A~ is the absorption at wavelength A and I~ is the light intensity at wavelength A. An analysis is obtained on the basis o~ the absorption at di~erent wavelengths using standard mathematical methods. The analyses may be used ~or identi~ying and/or quanti~ying samples with the aid o~ che~o~tric methods.
Chemom~tric methods for identi~ication are described, ~or example, in Ghosh et al, Melliand Textilberichte 5 (1988) 361.
In order to be able to identify samples of various types o~ carpets, a mathematical analysis is made to establish the combination o~ wavelengths which ensures the best separation between the di~erent materials to be identi~ied. For a series o~ used and unused carpets, spectra can be recorded in the near-in~rared range with a resolution o~ 2 nm. Theseparation is calculated using cluster analysis for all possible combinations of, for example, 3 wavelengths 2, A3).
To do this, the values o~, ~or example, A(~2)-A(A1) and A(A3)-A(~2) are calculated, where AA is the absorption at the wavelengths specified. When these CA 0222609~ 1997-12-31 W O97/02481 PCT~NL96100280 values are plotted on a graph, there appear to be separate clusters for the different materials at different wavelength combinations. The quality of separation increases accordingly as the clusters are better isolated from one another. Optimum separation is accomplished by selecting the combination of, for instance, 3 wavelengths at which the Mahalanobis' distances between the 3 clusters (4 dif~erent Mahalanobis' distances) are maximum.
To separate Polyamide-6, Polyamide-66, PET
and polypropylene, a combination of the absorptions at 2432, 2452 and 2478 appears to be optimum. In this way, it is possible to determine which discrete wavelengths should be measured for a particular application to clearly distinguish the different materials with the spectrometer o~ this invention. Then, using standard optical calculation methods, the locations of the holes in the plate can be easily determined depending on the particular combination of grating, entry slit, grating-to-plate distance, etc.
A more extensive and broad optimization is done mathematically using a technique called 'genetic algorithms'. In this technique, the full spectrum of various samples are taken using a high quality scanning spectrometer having good spectral resolution and signal/noise ratios. The set of spectra are trans~ormed to simulate spectral resolutions that are worse (e.g.
10 nm, 20 nm, 30 nm and 40 nm) since for cheap hand-held devices the resolution is less than for research-grade spectrometers. In addition, the signal/noise ratio and the accuracy of the wavelength selection is less for hand-held devices. These ef~ects must therefore also be included in the wavelength selection procedure.
In the genetic algorithms optimization procedure, the optimization conditions can be defined CA 0222609~ 1997-12-31 W O97/02481 PCTnNL96/00280 in any desired way. For example, the optimization conditions could be set to maximize the MD o~
Polyamide-6 and Polyamide-66, maximize the minimum o~
the MD's o~ Polyamide-6 to the other types o~
materials, maximize all the MD's, etc.
An experiment was conducted using the genetic algorithms technique. In the ~irst example, it was chosen to maximize the minimum o~ the MDs o~ Polyamide-6 to the other types o~ materials (Polyamide-6 -Polyamide-66, Polyamide-6 - Polypropylene, Polyamide-6 - PET). The allowed shi~ts o~ the selected wavelengths was set to be +6nm, the spectral resolution was chosen at 16 nm, the signal to noise ratio was set at 200.
Four wavelengths were chosen using these 15 parameters: 2382, 2430, 2452, 2472, which rendered the ~ollowing results:
MD Polyamide-6 - Polyamide-66: 8.2-11.8 MD Polyamide-6 - PET: 16.5-22.5 MD Polyamide-6 - Polypropylene: 8.2-11.9 Below the IR spectrometers according to the invention are described.
The ~irst type o~ IR spectrometer o~ this invention has been demonstrated to be capable o~
selecting narrower wavelength ranges than known spectrometers by dispersing incoming radiation.
Dispersion in this context, means the spatial distribution o~ the di~erent wavelengths which occur in a beam o~ radiation. One well known device use~ul to cause dispersion o~ an incoming beam o~ radiation is a grating. In this tirst spectrometer, a grating is pre~erably stationary and has between 100-4000 lines/mm. The re~lected or transmitted light converges, with or without the aid o~ a system o~ lenses, so that it enters the grating through an inlet aperture measuring between 100 and 1000 ~m.
At any distance behind th~ aperture, a point CA 0222609~ 1997-12-31 W O 97/02481 PCT~YLg~ Q0 in the plane perpendicular to the direction o~
radiation corresponds with a particular wavelength.
This being so, a given, desired wavelength, can be selected ~rom the spectrum by transmitting or 5 collecting a portion o~ the spectrum radiation which passes through the corresponding location.
The grating may be placed in the optical system such that the beam is re~lected by the post consumer waste material. The re~lected radiation may be collected, ~or example, in a number o~ suitably positioned detectors. A problem here is the minimum dimension o~ the available detectors, which enables adjacent wavelengths to be observed by the detector as well as the desired wavelength.
In a pre~erred embodiment o~ the IR
spectrometer o~ this invention, this problem is resolved by selecting a discrete wavelength with a plate that is opaque to IR radiation, positioned between the source and the detection system, so that no radiation can reach the detection system other than through openings in the plate. The plate is provided with openings at locations corresponding to the positions o~ the discrete wavelengths in the dispersed radiation to be selected.
The openings in the plate may be made very small, in any case substantially smaller than minimum dimensions o~ available detectors. The openings in the plate may also be positioned~ with very high accuracy.
In this way it is possible to accurately select the desired wavelengths ~rom the dispersed beam o~
radiation with high resolution.
In this embodiment the intensities o~ the di~erent wavelengths may be measured individually by placing a detector behind each opening in the plate or by using a plate and detector which are moveable relative to each other so that the detector can be -CA 0222609~ 1997-12-31 W O 97102481 PCTnYL96/00280 serially placed behind each opening in the plate. In this case, problems associated with a ~inite detector dimension do not arise because the location and size o~
the openings independently determine the wavelength selection and resolution o~ the spectrometer.
Another possibility, which a~ords greater design ~lexibility, is to connect a light conductor to each o~ the openings in the plate and to convey the radiation to the detection system through these conductors. In this case, separate detectors may again be used, or the individual light conductors may also be connected to, ~or instance, a rotary system or a slide system, whereby the individual conductors may be individually disposed in ~ront o~ a single detector.
Alternatively, the detector may be moveable so that it can be placed in ~ront o~ various stationary light conductors.
Motion o~ the detector or of the sliding or rotary system is pre~erably controlled by a computer system which also is capable o~ processing the measurement results. The results can, ~or instance, be presented on-line on a display. In this way, in a separation system ~or material ~low, an operator can intervene on the basis of the value shown. Also, the computer can be connected to and control a downstream mechanical system. The measurement results may also be used for controlling a production process.
In another embodiment, the grating may be placed in the optical system be~ore the radiation beam impinges on the test material. In this instance, dispersed light is passed through a plate with slots and thus selected light with the desired wavelengths is passed via light conductors onto the material. The amount o~ re~lected light is then measured to obtain light which may be analyzed to determine the type o~
material.
CA 0222609~ l997-l2-3l In this case, each opening o~ the plate allows light o~ a desired wavelengths to pass. The passed light is transmitted by a light conductor, having one end positioned adjacent the slot in the plate and the other end positioned so that the exiting radiation can be aimed at the material.
Aiming the exiting radiation can be accomplished, ~or example, by terminating the ends o~
the light conductors in a rotary system which, when rotating, allows a particular light conductor to irradiate the material while optically isolating the other conductors ~rom the material. By causing the rotary system to successively assume a number o~
di~erent positions, ~or example, by using a stepping motor, the material can successively be irradiated with dif~erent wavelengths and the intensity o~ the wavelengths can be individually measured. A system o~
lenses may be optionally provided to ensure that the material to be examined is adequately illuminated.
Suitable light conductors ~or use in this system are optical ~ibers which are transparent to the in~rared range between 1000-2000 nm. Quality glass ~ibers with a low SiOH content are suitable ~or the in~rared range between 2000-2500 nm. Chalcogenide or Ag-halide ~ibers are suitable ~or the mid-in~rared range. Other optical ~ibers that are transparent in the desired wavelength ranges may also be used. The diameter o~ these ~ibers is preferably between 100 and 1000 ~m.
The positions o~ the openings are calculated ~rom the desired wavelengths, the geometry of the spectrometer and the characteristics o~ the grating.
The desired wavelengths depend on the materials to be detected and separated which determine the location o~
the holes in the plate. The positions o~ the holes can be determined using cluster analysis, as described CA 0222609~ l997-l2-3l W O 97/02481 - 13 - PCTnNL96/00280 above.
The second type o~ IR spectrometer o~ this invention uses a combination o~ ~ilters placed on a ~ilter wheel which is driven at a high speed (10-200 Hz). Using this embodiment, the sample is illuminated using a set o~ lamps and di~use re~lected light is collected using a lens. The light is then directed through the ~ilter wheel and detected using a PbS or InGaAs detector.
Using a ~ilter wheel has several unique advantages. For example, since the ~ilter wheel blocks the light beam ~our times during each rotation, the dark current o~ the detector may be ~requently sampled and used to correct for temperature dri~t and other ~luctuations o~ the detector.
The collection angle ~or this system should be kept small, pre~erably less than 5~, to keep the spectral resolution o~ the ~ilter below 20 nm. The detector signals are processed using an on-board microprocessor.
Alternatively, the ~ilters can be used to select predetermined wavelengths ~rom a source o~
in~rared radiation be~ore the radiation impinges on the sample o~ post consumer waste carpet. In this system, a ~ilter wheel is rotated to allow in~rared radiation having a predetermined wavelength range to exit o~ the spectrometer. The emitted light is re~lected by the sample of post consumer waste carpet, and then detected by the detector.
Instead o~ using a ~ilter wheel, it may also be possible to use acoustic optical tunable ~ilters (AOTF). AOTF devices are based on acousto-optic e~ects in which the optical re~ractive index o~ a medium is altered using ultrasound (see Laser Focus World May, 1992). Essentially, AOTF devices are crystals which receive a light beam and transmit selected wavelengths CA 0222609~ l997-l2-3l W O97/02481 PCT~NL96/00280 o~ the incident light beam based on a ~requency o~ an acoustical input signal. Using an AOTF device, wavelengths could be selected by adjusting a ~requency o~ ultrasound applied to the AOTF device, thus eliminating moving parts associated with a ~ilter wheel.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments o~ the present invention will now be described more speci~ically with re~erence to the attached drawings, wherein:
Figure 1 is a side view o~ a hand-held spectrometer according to a first embodiment o~ this invention;
Figure 2 is a side view o~ a hand-held spectrometer according to a second embodiment o~ this invention;
Figure 3 is a side view o~ a hand-held spectrometer according to a third embodiment o~ this invention;
Figure 4 is a side view o~ a hand-held spectrometer according to a fourth embodiment o~ this invention;
Figure 5 is a side view of a hand-held spectrometer according to a ~ifth embodiment o~ this invention;
Figure 6 is a ~ilter wheel ~or use with the hand-held spectrometer illustrated in Figure 5; and Figure 7 is a side view o~ a hand-held spectrometer according to a sixth embodiment o~ this invention.
nr.~ATr.Fn nrCc~TpTIoN OF 1~ PR~P~RE~D EMBOD~
The boundaries of the radiation beams are shown in the Figs. by dot-dash lines, and individual light rays are indicated by dotted lines. In Fig. 1, a CA 0222609~ l997-l2-3l W O 97/02481 PCT~NL96/00280 light source 1 is placed in a reflector casing 2. Light emitted from the light source 1 is directed onto a material to be examined 3. Reflected radiation converges at a lens 4, whereupon the central beam impinges on a grating 6 through an entrance slit 5. The radiation is dispersed by the grating 6 into different wavelengths. A plate 7 is placed in the dispersed radiation beam, and has openings 8 which correspond to selected wavelength positions within the spectrum.
First ends of light conductors 9 are installed in the openings 8 in plate 7. The other ends of the light conductors are each inserted into an opening in selector plate 10, with the light conductors ending at a surface 11 of the plate. The selector plate 10 can be moved with a stepping motor (not shown) so that the detector 12 only sees the light from a particular light conductor through an opening 13 in an opaque plate 14 inserted between the selector plate 10 and the detector 12. The detector 12 is connected to a processing system (not shown).
In Fig. 2, a light source 201 is placed in a reflector casing 202. The light converges at a lens 204 so that it impinges on a grating 206 through an entrance slit 205. The radiation is dispersed by the grating into different wavelengths. A plate 207 is placed in the dispersed radiation beam, which plate is provided with openings 208 positionally corresponding to selected wavelengths. Firs~t ends of light conductors 209 are installed in the openings 208 of plate 207. The other ends of the light conductors are each inserted into selector plate 210, with the light conductors ending at the surface 211 of the plate 210. An opaque plate 214 is provided behind this selector plate with an opening 213. This plate 214 can be moved with a stepping motor (not shown) so that only the light from a particular light conductor can pass through the CA 0222609~ 1997-12-31 W O 97/02481 PCT~L96/OOZ80 opening 213. The light passing through this opening 213 diverges at a lens 216 whereupon the diverged radiation impinges on the material to be examined 203. The radiation reflected by the material converges at lens 217 and then impinges on detector 212. The detector is connected to a processing system (not shown).
The IR spectrometer o~ the invention can be made very compact ~or easy handling. The IR
spectrometer may be advantageously used in the tield recycling of plastic materials in general, provided that the speci~ic wavelengths are selected as appropriate ~or the given material characteristics.
Figs. 3 and 4 are identical to Figs. 1 and 2, respectively, except that they illustrate the situation where light passing through the sample material is collected and evaluated in the spectrometer.
Fig. 5 shows a second embodiment of a device which may be used for determining the spectral ~ualities o~ post consumer waste carpet. In Fig. 5, a spectrometer 100 has a rotary filter wheel 102 which is driven by a motor 104.
Light is provided by one or more lamps 106 on one side o~ the spectrometer 100 to impinge on a sample of post consumer waste carpet 108. Light reflected by the sample 108 is collected by a lens 110, is directed through the rotary ~ilter wheel 102 and sensed by a PbS
or InGaAs detector 112.
One example of a rotary ~ilter wheel 102 is shown in Fig. 6. In this example, 4 ~ilters 114 (A-D) are provided on the rotary filter wheel 102. A hole 116 is provided in the center o~ the rotary filter wheel 102 to receive a drive sha~t 118 extending ~rom the motor 104.
In operation, the motor 104 causes the rotary filter wheel 102 to rotate so that light passing through lens 110 will be filtered according to the , CA 0222609~ l997-l2-3l W O 97/02481 PCTnNL~5.'~L29C
speci~ic qualities possessed by the ~ilters 114. The detector 112 detects the ~iltered light and provides signals to an electronic circuit 120 which outputs the result.
Fig. 7 iS another example o~ a spectrometer 100 which utilizes a rotary ~ilter wheel 102, except that the light is ~iltered be~ore being incident on the sample o~ post consumer waste carpet 108. As shown in Fig. 7, a light source 106 produces in~rared radiation 10 which is ~iltered by a rotary ~ilter system 102, 104, 118. The f ilter passes predetermined wavelengths which exit the spectrometer housing via optics 122.
A~ter exiting the spectrometer housing, the predetermined wavelengths impinge on the sample o~ post consumer waste carpet 108 and are re~lected by the sample o~ post consumer waste carpet 108. One or more detectors 112 detect the re~lected light and output a signal to an electronic circuit 120 which outputs the result. Although this example has illustrated optics which emit light ~rom only one side o~ the spectrometer, the light passing through the ~ilter could alternatively be divided and exit the spectrometer at various locations.
It is understood that various other modi~ications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit o~ this invention. Accordingly, it is not intended that the scope o~ the claims appended hereto be limited to the description as set ~orth herein, but rather that the claims be construed as encompassing all the features o~ patentable novelty that reside in the present invention, including all ~eatures that would be treated as equivalents thereo~
by those skilled in the art which this invention pertains.
SPECTRO~lElE3R
BAC~GROUND OF THE lNV~ ION
Field of the Invention The invention relates to a method and apparatus for identifying post consumer or post industrial waste carpet using an infrared (IR) spectrometer, and more particularly to a method of identi~ying post consumer or post industrial waste carpet using a hand-held IR spectrometer having an IR
radiation source which illuminates the post consumer or post industrial waste carpet with IR radiation, a selector for selecting a predetermined number of discrete wavelengths of radiation and an IR detection system for detecting radiation reflected by the post consumer or post industrial waste carpet. The invention also relates to a method and apparatus for identifying Polyamide-6 and/or Polyamide-66 containing material using a hand-held IR-spectrometer enabling sorting of the Polyamides.
De~cription of the Related Art Recycling post consumer or post industrial waste carpet material requires the post consumer or post industrial waste carpet material to be sorted according to the type of face fiber used to manufacture the carpet. Throughout this application, applicants will repeatedly refer to "post consumer waste carpet", which is used by applicants as a generic term encompassing both post consumer waste carpet, post industrial waste carpet and Polyamide-6 and/or Polyamide-66 containing waste streams.
CA 0222609~ 1997-12-31 W O 97/02481 PCTnNL~ r-r Currently, carpets employ ~ace ~ibers produced ~rom materials such as Polyamide-6, Polyamide-66, Polypropylene, Wool, Polyester and blends o~ these component products. For a recycling program to be success~ul, it must be easy to accurately identi~y the type o~ ~ace ~iber used by the carpet.
One method o~ identi~ying carpets is to print a code on the back o~ the carpet. Un~ortunately, although this is the most ~ool-proo~ o~ all possible methods, it requires the carpets to have been marked when manu~actured. There~ore, even i~ marking was started today, this method would not become e~ective ~or approximately 10 years due to the expected li~e o~
the marked carpet. Further, this method may not be satis~actory when used with glued carpets, since the backing o~ glued carpets may be damaged, thus rendering the identi~ication code di~icult to read.
Alternatively, it is possible to identi~y the type o~ carpet by detecting the melting point o~ the ~ace ~iber. This identi~ication method is inadeguate because it is not able to separate streams o~ Polyester and Polyamide-66. Further, blends o~ the various types o~ ~ace ~ibers cannot be distinguished. Devices which utilize the melting point of the carpet material as a distinguishing characteristic are also de~icient in that they generally tend to have a long warm-up time, thus reducing e~iciency, and can be dangerous since they necessarily involve hot components.
A third way to identi~y the type o~ ~ace material used on a particular waste carpet sample is to use a spectroscope. It is well known that various materials can be identi~ied using vibrational spectroscopic technigues like mid-in~rared and near in~rared spectroscopy. In particular, near in~rared spectroscopy is a well known method, e.g. ~or the sorting o~ bottles. IR spectroscopy can be conducted on -CA 0222609~ 1997-12-31 W O 97/02481 PCTnNL96/00280 transparent materials by analyzing radiation passing through the materials, and on substances which are opaque to IR radiation by analyzing the di~use radiation reflected by the material. To con~orm with~ 5 the customary usage in optics, this application will sometimes re~er to IR radiation as "light".
IR spectrometers, ~or both the near-in~rared range (800-2500 nm) and the mid-in~rared range (2500-25000 nm), are o~ten used to identi~y and quanti~y materials on the basis o~ the material characteristics which cause them to absorb or re~lect particular wavelengths. In many cases, these characteristic ~requencies are only slightly dif~erent ~or di~erent materials. It is there~ore important to use a high spectral resolution spectrometer, especially when attempting to distinguish various materials mixed together.
An IR spectrometer generally includes a source which emits radiation in the desired wavelength range and auxiliary optics such as lenses and mirrors to ~orm the radiation into a beam of suitable shape and dimensions and to guide it along a light path. As a rule, all elements that make up the spectrometer are accommodated in an enclosure which preferably is sealed to prevent dust ~rom inter~ering with the components.
The light source is pre~erably placed in a re~lector casing so that the spectrometer can obtain as much light as possible. The light source is pre~erably incorporated in the optical casing, so that light egresses from the spectrometer via an optically transparent window to impinge on the target material.
The transparent window may be, ~or instance, glass or high-guality guartz or may be made of for instance RBr, RC1, ZnSe, RRS~, CaF2 or MgF2 for the mid-in~rared range.
The beam is directed at a site on the CA 0222609~ l997-l2-3l material to be examined. The reflected radiation is then collected, f'ormed to have a desired beam geometry and eventually directed onto a detection system. This detection system normally includes a detector capable of measuring the intensity o~ the incident radiation.
Several detectors which may be used in the near-in~rared range include PbS and InGaAs detectors, and detectors which may be used in the mid-inf'rared range include detectors made ~rom deuterized triglycinesulphate (DTGS).
There are several basic types of IR
spectrometers. Two types o~ IR spectrometers are discussed below. In the f'irst type, discrete wavelengths are selected by passing ref'lected radiation through dif'f'erent f'ilters that are only transparent to a particular wavelength range. In the second type, a beam of reflected IR radiation is dispersed and allowed to impinge on a diode array. Unf'ortunately, diode arrays o~ this nature and having the desired resolving power are very expensive, and selection of' the desired wavelength f'rom the absorbed spectrum must take place in a later phase in the downstream processing equipment, thus increasing the amount of' support electronics necessary to utilize the spectrometer.
The relationship between the intensity and the wavelength of the reflected or transmitted light ~rom a particular material is called the spectrum. The detector is linked to a processing system which converts the detector signals into a spectral ~orm accessible to the user or a computer such as a curve or numerical values.
In general, the mid- and near-infrared spectra of various types o~ ~ibers used in carpets differ signi~icantly. However, t~e spectra of polyamide-6 and polysmide-66 dif er only slightly: the mid-inf'rared spectrum is completely identical and the CA 0222609~ l997-l2-3l W O 97/02481 PCT~NL96/00280 - 5 -near infrared spectra is only slightly different in the 2000-2500 nm spectral range.
The quality of identification obtainable using a given spectroscopic system is expressed as the Mahalonobis-distance (MD), which is the center-to-center distance between the various clusters in relation to the spread within the clusters. For good separation, a minimum MD value of about 6 is required, but ideally the value should be larger than 10.
Unfortunately, although Ghosh and Rogers (Melliand Textilberichte 5, 1988, pages 361-364) indicated that the scanning spectrometer in their system achieved very good MD results for sorting Polyamide-6 and Polyamide-66 ~ibers (MD = 18), the size and price of the scanning spectrometer renders this system largely unsuitable for use in the carpet recycling business.
Ghosh and Roogers also demonstrated that it is possible to identify nylon 6 and nylon 66 fibers used for carpet production using a Bran&Luebbe (Formerly Technicon) InfraAlyzer 500C, with a combination of 3 filters, (2250, 2270 and 2310 nm).
These reported results are also deceiving, in that used carpets have different fiber materials than new carpets due to wear and contamination, thus complicating identification. For example, using these same 3 ~ilters on a sample o~ 113 post consumer carpet waste samples, applicants discovered that the obtainable MD ranged between 4 and 1.2, depending on the resolution of the spectrometer. As indicated above, results of this nature are clearly insu~ficient to accurately discriminate between various carpet samples.
Accordingly, it still has not been demonstrated to be possible to distinguish various types of post consumer waste carpet utilizing a cheap, small and portable spectrometer based on selected wavelengths.
CA 0222609~ 1997-12-31 W O97/02481 PCTn~L96/00280 -- 6 --Likewise, although portable inexpensive IR
~ilter-based spectrometers are commercially available ~or task speci~ic applications, such as to determine the moisture content o~ various materials, no one has been able to develop a hand-held spectrometer which is able to satis~actorily distinguish between various types o~ carpet ~ace material so that the spectrometer can be suitably used in recycling post consumer waste carpet.
S~MM~RY OF THE lNv~ ION
One object o~ the invention is to provide a method o~ reliably analyzing post consumer carpet waste using a hand-held IR spectrometer. To do this, the lS invention utilizes a hand-held spectrometer which is capable o~ measuring at a number o~ discrete wavelengths with su~icient resolution.
Two such hand-held spectrometers are envisioned in this respect. The ~irst hand-held spectrometer is capable o~ measuring a number o~
discrete wavelengths with good resolution by utilizing a radiation selector which disperses the radiation and selects discrete wavelengths ~rom the dispersed radiation using a plate provided with openings at locations corresponding to the positions o~ the discrete wavelengths in the dispersed radiation to be selected.
The second hand-held spectrometer is also capable o~ measuring a number o~ discrete wavelengths, but utilizes ~ilters which pass particular selected wavelengths optimal ~or use in the carpet recycling business.
Depending on the application to which the spectrometer will be applied, the spectra in the near-in~rared range or the mid-in~rared range o~ a series of samples are recorded using a high-resolution CA 0222609~ 1997-12-31 W O 97/02481 PCTnNL96100280 spectrometer. These high-resolution spectra are used to determine the combination o~ absorptions at dif~erent wavelengths which yield sufficient in~ormation ~or discriminating one polymer ~rom another. In the case of carpet recycling, ~or instance, one might wish to know i~ a carpet is made of Polypropylene, Polyamide-6, Polyamide- 66 or Polyethylene Terephthalate (PET).
Absorption o~ the detector should be checked against a reference material o~ a known substance.
Suitable reference materials for diffuse reflection in the near-in~rared range include, ~or example, small ceramic plates and small teflon plates.
Absorption is calculated as follows:
AA = l~g(I~(..mple)/IA(r.~.r.nc. mllt~ri~l))~ ... (1) where A~ is the absorption at wavelength A and I~ is the light intensity at wavelength A. An analysis is obtained on the basis o~ the absorption at di~erent wavelengths using standard mathematical methods. The analyses may be used ~or identi~ying and/or quanti~ying samples with the aid o~ che~o~tric methods.
Chemom~tric methods for identi~ication are described, ~or example, in Ghosh et al, Melliand Textilberichte 5 (1988) 361.
In order to be able to identify samples of various types o~ carpets, a mathematical analysis is made to establish the combination o~ wavelengths which ensures the best separation between the di~erent materials to be identi~ied. For a series o~ used and unused carpets, spectra can be recorded in the near-in~rared range with a resolution o~ 2 nm. Theseparation is calculated using cluster analysis for all possible combinations of, for example, 3 wavelengths 2, A3).
To do this, the values o~, ~or example, A(~2)-A(A1) and A(A3)-A(~2) are calculated, where AA is the absorption at the wavelengths specified. When these CA 0222609~ 1997-12-31 W O97/02481 PCT~NL96100280 values are plotted on a graph, there appear to be separate clusters for the different materials at different wavelength combinations. The quality of separation increases accordingly as the clusters are better isolated from one another. Optimum separation is accomplished by selecting the combination of, for instance, 3 wavelengths at which the Mahalanobis' distances between the 3 clusters (4 dif~erent Mahalanobis' distances) are maximum.
To separate Polyamide-6, Polyamide-66, PET
and polypropylene, a combination of the absorptions at 2432, 2452 and 2478 appears to be optimum. In this way, it is possible to determine which discrete wavelengths should be measured for a particular application to clearly distinguish the different materials with the spectrometer o~ this invention. Then, using standard optical calculation methods, the locations of the holes in the plate can be easily determined depending on the particular combination of grating, entry slit, grating-to-plate distance, etc.
A more extensive and broad optimization is done mathematically using a technique called 'genetic algorithms'. In this technique, the full spectrum of various samples are taken using a high quality scanning spectrometer having good spectral resolution and signal/noise ratios. The set of spectra are trans~ormed to simulate spectral resolutions that are worse (e.g.
10 nm, 20 nm, 30 nm and 40 nm) since for cheap hand-held devices the resolution is less than for research-grade spectrometers. In addition, the signal/noise ratio and the accuracy of the wavelength selection is less for hand-held devices. These ef~ects must therefore also be included in the wavelength selection procedure.
In the genetic algorithms optimization procedure, the optimization conditions can be defined CA 0222609~ 1997-12-31 W O97/02481 PCTnNL96/00280 in any desired way. For example, the optimization conditions could be set to maximize the MD o~
Polyamide-6 and Polyamide-66, maximize the minimum o~
the MD's o~ Polyamide-6 to the other types o~
materials, maximize all the MD's, etc.
An experiment was conducted using the genetic algorithms technique. In the ~irst example, it was chosen to maximize the minimum o~ the MDs o~ Polyamide-6 to the other types o~ materials (Polyamide-6 -Polyamide-66, Polyamide-6 - Polypropylene, Polyamide-6 - PET). The allowed shi~ts o~ the selected wavelengths was set to be +6nm, the spectral resolution was chosen at 16 nm, the signal to noise ratio was set at 200.
Four wavelengths were chosen using these 15 parameters: 2382, 2430, 2452, 2472, which rendered the ~ollowing results:
MD Polyamide-6 - Polyamide-66: 8.2-11.8 MD Polyamide-6 - PET: 16.5-22.5 MD Polyamide-6 - Polypropylene: 8.2-11.9 Below the IR spectrometers according to the invention are described.
The ~irst type o~ IR spectrometer o~ this invention has been demonstrated to be capable o~
selecting narrower wavelength ranges than known spectrometers by dispersing incoming radiation.
Dispersion in this context, means the spatial distribution o~ the di~erent wavelengths which occur in a beam o~ radiation. One well known device use~ul to cause dispersion o~ an incoming beam o~ radiation is a grating. In this tirst spectrometer, a grating is pre~erably stationary and has between 100-4000 lines/mm. The re~lected or transmitted light converges, with or without the aid o~ a system o~ lenses, so that it enters the grating through an inlet aperture measuring between 100 and 1000 ~m.
At any distance behind th~ aperture, a point CA 0222609~ 1997-12-31 W O 97/02481 PCT~YLg~ Q0 in the plane perpendicular to the direction o~
radiation corresponds with a particular wavelength.
This being so, a given, desired wavelength, can be selected ~rom the spectrum by transmitting or 5 collecting a portion o~ the spectrum radiation which passes through the corresponding location.
The grating may be placed in the optical system such that the beam is re~lected by the post consumer waste material. The re~lected radiation may be collected, ~or example, in a number o~ suitably positioned detectors. A problem here is the minimum dimension o~ the available detectors, which enables adjacent wavelengths to be observed by the detector as well as the desired wavelength.
In a pre~erred embodiment o~ the IR
spectrometer o~ this invention, this problem is resolved by selecting a discrete wavelength with a plate that is opaque to IR radiation, positioned between the source and the detection system, so that no radiation can reach the detection system other than through openings in the plate. The plate is provided with openings at locations corresponding to the positions o~ the discrete wavelengths in the dispersed radiation to be selected.
The openings in the plate may be made very small, in any case substantially smaller than minimum dimensions o~ available detectors. The openings in the plate may also be positioned~ with very high accuracy.
In this way it is possible to accurately select the desired wavelengths ~rom the dispersed beam o~
radiation with high resolution.
In this embodiment the intensities o~ the di~erent wavelengths may be measured individually by placing a detector behind each opening in the plate or by using a plate and detector which are moveable relative to each other so that the detector can be -CA 0222609~ 1997-12-31 W O 97102481 PCTnYL96/00280 serially placed behind each opening in the plate. In this case, problems associated with a ~inite detector dimension do not arise because the location and size o~
the openings independently determine the wavelength selection and resolution o~ the spectrometer.
Another possibility, which a~ords greater design ~lexibility, is to connect a light conductor to each o~ the openings in the plate and to convey the radiation to the detection system through these conductors. In this case, separate detectors may again be used, or the individual light conductors may also be connected to, ~or instance, a rotary system or a slide system, whereby the individual conductors may be individually disposed in ~ront o~ a single detector.
Alternatively, the detector may be moveable so that it can be placed in ~ront o~ various stationary light conductors.
Motion o~ the detector or of the sliding or rotary system is pre~erably controlled by a computer system which also is capable o~ processing the measurement results. The results can, ~or instance, be presented on-line on a display. In this way, in a separation system ~or material ~low, an operator can intervene on the basis of the value shown. Also, the computer can be connected to and control a downstream mechanical system. The measurement results may also be used for controlling a production process.
In another embodiment, the grating may be placed in the optical system be~ore the radiation beam impinges on the test material. In this instance, dispersed light is passed through a plate with slots and thus selected light with the desired wavelengths is passed via light conductors onto the material. The amount o~ re~lected light is then measured to obtain light which may be analyzed to determine the type o~
material.
CA 0222609~ l997-l2-3l In this case, each opening o~ the plate allows light o~ a desired wavelengths to pass. The passed light is transmitted by a light conductor, having one end positioned adjacent the slot in the plate and the other end positioned so that the exiting radiation can be aimed at the material.
Aiming the exiting radiation can be accomplished, ~or example, by terminating the ends o~
the light conductors in a rotary system which, when rotating, allows a particular light conductor to irradiate the material while optically isolating the other conductors ~rom the material. By causing the rotary system to successively assume a number o~
di~erent positions, ~or example, by using a stepping motor, the material can successively be irradiated with dif~erent wavelengths and the intensity o~ the wavelengths can be individually measured. A system o~
lenses may be optionally provided to ensure that the material to be examined is adequately illuminated.
Suitable light conductors ~or use in this system are optical ~ibers which are transparent to the in~rared range between 1000-2000 nm. Quality glass ~ibers with a low SiOH content are suitable ~or the in~rared range between 2000-2500 nm. Chalcogenide or Ag-halide ~ibers are suitable ~or the mid-in~rared range. Other optical ~ibers that are transparent in the desired wavelength ranges may also be used. The diameter o~ these ~ibers is preferably between 100 and 1000 ~m.
The positions o~ the openings are calculated ~rom the desired wavelengths, the geometry of the spectrometer and the characteristics o~ the grating.
The desired wavelengths depend on the materials to be detected and separated which determine the location o~
the holes in the plate. The positions o~ the holes can be determined using cluster analysis, as described CA 0222609~ l997-l2-3l W O 97/02481 - 13 - PCTnNL96/00280 above.
The second type o~ IR spectrometer o~ this invention uses a combination o~ ~ilters placed on a ~ilter wheel which is driven at a high speed (10-200 Hz). Using this embodiment, the sample is illuminated using a set o~ lamps and di~use re~lected light is collected using a lens. The light is then directed through the ~ilter wheel and detected using a PbS or InGaAs detector.
Using a ~ilter wheel has several unique advantages. For example, since the ~ilter wheel blocks the light beam ~our times during each rotation, the dark current o~ the detector may be ~requently sampled and used to correct for temperature dri~t and other ~luctuations o~ the detector.
The collection angle ~or this system should be kept small, pre~erably less than 5~, to keep the spectral resolution o~ the ~ilter below 20 nm. The detector signals are processed using an on-board microprocessor.
Alternatively, the ~ilters can be used to select predetermined wavelengths ~rom a source o~
in~rared radiation be~ore the radiation impinges on the sample o~ post consumer waste carpet. In this system, a ~ilter wheel is rotated to allow in~rared radiation having a predetermined wavelength range to exit o~ the spectrometer. The emitted light is re~lected by the sample of post consumer waste carpet, and then detected by the detector.
Instead o~ using a ~ilter wheel, it may also be possible to use acoustic optical tunable ~ilters (AOTF). AOTF devices are based on acousto-optic e~ects in which the optical re~ractive index o~ a medium is altered using ultrasound (see Laser Focus World May, 1992). Essentially, AOTF devices are crystals which receive a light beam and transmit selected wavelengths CA 0222609~ l997-l2-3l W O97/02481 PCT~NL96/00280 o~ the incident light beam based on a ~requency o~ an acoustical input signal. Using an AOTF device, wavelengths could be selected by adjusting a ~requency o~ ultrasound applied to the AOTF device, thus eliminating moving parts associated with a ~ilter wheel.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments o~ the present invention will now be described more speci~ically with re~erence to the attached drawings, wherein:
Figure 1 is a side view o~ a hand-held spectrometer according to a first embodiment o~ this invention;
Figure 2 is a side view o~ a hand-held spectrometer according to a second embodiment o~ this invention;
Figure 3 is a side view o~ a hand-held spectrometer according to a third embodiment o~ this invention;
Figure 4 is a side view o~ a hand-held spectrometer according to a fourth embodiment o~ this invention;
Figure 5 is a side view of a hand-held spectrometer according to a ~ifth embodiment o~ this invention;
Figure 6 is a ~ilter wheel ~or use with the hand-held spectrometer illustrated in Figure 5; and Figure 7 is a side view o~ a hand-held spectrometer according to a sixth embodiment o~ this invention.
nr.~ATr.Fn nrCc~TpTIoN OF 1~ PR~P~RE~D EMBOD~
The boundaries of the radiation beams are shown in the Figs. by dot-dash lines, and individual light rays are indicated by dotted lines. In Fig. 1, a CA 0222609~ l997-l2-3l W O 97/02481 PCT~NL96/00280 light source 1 is placed in a reflector casing 2. Light emitted from the light source 1 is directed onto a material to be examined 3. Reflected radiation converges at a lens 4, whereupon the central beam impinges on a grating 6 through an entrance slit 5. The radiation is dispersed by the grating 6 into different wavelengths. A plate 7 is placed in the dispersed radiation beam, and has openings 8 which correspond to selected wavelength positions within the spectrum.
First ends of light conductors 9 are installed in the openings 8 in plate 7. The other ends of the light conductors are each inserted into an opening in selector plate 10, with the light conductors ending at a surface 11 of the plate. The selector plate 10 can be moved with a stepping motor (not shown) so that the detector 12 only sees the light from a particular light conductor through an opening 13 in an opaque plate 14 inserted between the selector plate 10 and the detector 12. The detector 12 is connected to a processing system (not shown).
In Fig. 2, a light source 201 is placed in a reflector casing 202. The light converges at a lens 204 so that it impinges on a grating 206 through an entrance slit 205. The radiation is dispersed by the grating into different wavelengths. A plate 207 is placed in the dispersed radiation beam, which plate is provided with openings 208 positionally corresponding to selected wavelengths. Firs~t ends of light conductors 209 are installed in the openings 208 of plate 207. The other ends of the light conductors are each inserted into selector plate 210, with the light conductors ending at the surface 211 of the plate 210. An opaque plate 214 is provided behind this selector plate with an opening 213. This plate 214 can be moved with a stepping motor (not shown) so that only the light from a particular light conductor can pass through the CA 0222609~ 1997-12-31 W O 97/02481 PCT~L96/OOZ80 opening 213. The light passing through this opening 213 diverges at a lens 216 whereupon the diverged radiation impinges on the material to be examined 203. The radiation reflected by the material converges at lens 217 and then impinges on detector 212. The detector is connected to a processing system (not shown).
The IR spectrometer o~ the invention can be made very compact ~or easy handling. The IR
spectrometer may be advantageously used in the tield recycling of plastic materials in general, provided that the speci~ic wavelengths are selected as appropriate ~or the given material characteristics.
Figs. 3 and 4 are identical to Figs. 1 and 2, respectively, except that they illustrate the situation where light passing through the sample material is collected and evaluated in the spectrometer.
Fig. 5 shows a second embodiment of a device which may be used for determining the spectral ~ualities o~ post consumer waste carpet. In Fig. 5, a spectrometer 100 has a rotary filter wheel 102 which is driven by a motor 104.
Light is provided by one or more lamps 106 on one side o~ the spectrometer 100 to impinge on a sample of post consumer waste carpet 108. Light reflected by the sample 108 is collected by a lens 110, is directed through the rotary ~ilter wheel 102 and sensed by a PbS
or InGaAs detector 112.
One example of a rotary ~ilter wheel 102 is shown in Fig. 6. In this example, 4 ~ilters 114 (A-D) are provided on the rotary filter wheel 102. A hole 116 is provided in the center o~ the rotary filter wheel 102 to receive a drive sha~t 118 extending ~rom the motor 104.
In operation, the motor 104 causes the rotary filter wheel 102 to rotate so that light passing through lens 110 will be filtered according to the , CA 0222609~ l997-l2-3l W O 97/02481 PCTnNL~5.'~L29C
speci~ic qualities possessed by the ~ilters 114. The detector 112 detects the ~iltered light and provides signals to an electronic circuit 120 which outputs the result.
Fig. 7 iS another example o~ a spectrometer 100 which utilizes a rotary ~ilter wheel 102, except that the light is ~iltered be~ore being incident on the sample o~ post consumer waste carpet 108. As shown in Fig. 7, a light source 106 produces in~rared radiation 10 which is ~iltered by a rotary ~ilter system 102, 104, 118. The f ilter passes predetermined wavelengths which exit the spectrometer housing via optics 122.
A~ter exiting the spectrometer housing, the predetermined wavelengths impinge on the sample o~ post consumer waste carpet 108 and are re~lected by the sample o~ post consumer waste carpet 108. One or more detectors 112 detect the re~lected light and output a signal to an electronic circuit 120 which outputs the result. Although this example has illustrated optics which emit light ~rom only one side o~ the spectrometer, the light passing through the ~ilter could alternatively be divided and exit the spectrometer at various locations.
It is understood that various other modi~ications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit o~ this invention. Accordingly, it is not intended that the scope o~ the claims appended hereto be limited to the description as set ~orth herein, but rather that the claims be construed as encompassing all the features o~ patentable novelty that reside in the present invention, including all ~eatures that would be treated as equivalents thereo~
by those skilled in the art which this invention pertains.
Claims (24)
1. A hand-held infrared spectrometer for use in analyzing post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising:
an infrared radiation source for illuminating the waste (carpet) with infrared radiation;
a selector for selecting a number of discrete wavelengths from infrared radiation reflected by the waste (carpet) in order to get a Mahalanobis-distance of at least 6; and an infrared detection system for detecting the selected discrete wavelengths.
an infrared radiation source for illuminating the waste (carpet) with infrared radiation;
a selector for selecting a number of discrete wavelengths from infrared radiation reflected by the waste (carpet) in order to get a Mahalanobis-distance of at least 6; and an infrared detection system for detecting the selected discrete wavelengths.
2. A hand-held infrared spectrometer according to claim 1, wherein the selector comprises a dispersing device which disperses the radiation and a discrete wavelength selector which selects the discrete wavelengths from the dispersed radiation.
3. A hand-held infrared spectrometer according to claim 1, wherein the selector comprises a filter system having a plurality of filters for transmitting only predetermined wavelengths of radiation.
4. A hand-held infrared spectrometer for use in analyzing post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising:
an infrared radiation source for irradiating infrared radiation toward a sample of waste (carpet);
a radiation selector which selects a plurality of discrete wavelengths, said radiation selector comprising a dispersing device which disperses the radiation and a discrete wavelength selector which selects the discrete wavelengths from the dispersed radiation; and a detection system which detects the discrete wavelengths.
Claims
an infrared radiation source for irradiating infrared radiation toward a sample of waste (carpet);
a radiation selector which selects a plurality of discrete wavelengths, said radiation selector comprising a dispersing device which disperses the radiation and a discrete wavelength selector which selects the discrete wavelengths from the dispersed radiation; and a detection system which detects the discrete wavelengths.
Claims
5. A hand-held infrared spectrometer according to claim 4, wherein the radiation is dispersed and select wavelengths are selected before the radiation impinges on the sample of waste (carpet).
6. A hand-held infrared spectrometer according to claim 4, wherein the radiation is dispersed and select wavelengths are selected after the radiation impinges on the sample of waste (carpet).
7. A hand-held infrared spectrometer for use in analyzing post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising:
an infrared radiation source for irradiating infrared radiation on a sample of waste (carpet);
a radiation selector which selects a plurality of discrete wavelengths from radiation reflected by the sample of waste (carpet), said radiation selector comprising a dispersing device which disperses the reflected radiation and a discrete wavelength selector which selects the discrete wavelengths from the dispersed radiation; and a detection system which detects the discrete wavelengths.
an infrared radiation source for irradiating infrared radiation on a sample of waste (carpet);
a radiation selector which selects a plurality of discrete wavelengths from radiation reflected by the sample of waste (carpet), said radiation selector comprising a dispersing device which disperses the reflected radiation and a discrete wavelength selector which selects the discrete wavelengths from the dispersed radiation; and a detection system which detects the discrete wavelengths.
8. A hand-held infrared spectrometer according to claim 7, wherein said discrete wavelength selector comprises a plate provided with openings in locations corresponding with positions of selected discrete wavelengths in the dispersed radiation, said plate being opaque to IR
radiation and being placed between the source and the detection system so that radiation cannot reach the detection system except through said openings in said plate.
- New set of Claims (continued) -
radiation and being placed between the source and the detection system so that radiation cannot reach the detection system except through said openings in said plate.
- New set of Claims (continued) -
9. A hand-held infrared spectrometer according to claim 8, wherein said detection system comprises plural detectors, one of each of said detectors being provided behind a respective opening in said plate.
10. A hand-held infrared spectrometer according to claim 8, wherein said detection system comprises a detector which can be disposed behind more than on of said openings in said plate.
11. A hand-held infrared spectrometer according to claim 8, further comprising a light conductor system, said light conductor system having a plurality of light conductors, each said light conductor connected to one of said openings in said plate to convey light passing through said opening in said plate to said detection system.
12. A hand-held infrared spectrometer according to claim 11, wherein said detection system comprises plural detectors and each said light conductor is connected to one of said detectors.
13. A hand-held infrared spectrometer according to claim 11, wherein the detection system and the light conductors are moveable relative to each other so that said light conductors can individually convey light to said detection system.
14. A hand-held infrared spectrometer for use in analyzing post consumer or post-industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising:
an infrared radiation source for irradiating infrared radiation on a sample waste (carpet);
a filter system comprising a plurality of filters for transmitting only predetermined wavelengths of radiation reflected with a collection angle of less than 5°; and a detection system which detects radiation transmitted by the filter system.
- New set of Claims (continued) -
an infrared radiation source for irradiating infrared radiation on a sample waste (carpet);
a filter system comprising a plurality of filters for transmitting only predetermined wavelengths of radiation reflected with a collection angle of less than 5°; and a detection system which detects radiation transmitted by the filter system.
- New set of Claims (continued) -
15. A hand-held infrared spectrometer according to claim 14, wherein said infrared radiation source irradiates infrared radiation on a sample of waste (carpet) and said filter system transmits only predetermined wavelengths of radiation reflected by the sample of waste (carpet).
16. A hand-held infrared spectrometer according to claim 14, wherein said filter system transmits only predetermined wavelengths of radiation to be reflected by the sample of waste (carpet).
17. A hand-held infrared spectrometer according to claim 14, wherein said filter system employs a rotary filter wheel having three or more filters.
18. A hand-held infrared spectrometer according to claim 14, wherein said filter system employs a rotary filter wheel having four filters which pass light having wavelengths of 2382 nm ~ 20 nm, 2430 nm ~ 20 nm, 2452 nm ~ 20 nm, and 2472 nm ~ 20 nm respectively.
19. A hand-held infrared spectrometer according to claim 14 wherein said filter system is an acousto optical tunable filter.
20. A method of discriminating between various types of post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
providing a hand-held infrared spectrometer; and utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
providing a hand-held infrared spectrometer; and utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
21. A method of discriminating between various types of post consumer of post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
- New set of Claims (continued) -Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
providing a hand-held infrared spectrometer;
irradiating infrared radiation onto a sample (carpet) waste from an infrared radiation source in said hand-held infrared spectrometer;
selecting a plurality of discrete wavelengths from radiation reflected by the sample of waste (carpet) by utilizing a radiation selector in said hand-held infrared spectrometer, said step of selecting a plurality of discrete wavelengths comprising the substep of dispersing the reflected radiation utilizing a dispersing device and the substep of selecting a plurality of discrete wavelengths from the dispersed radiation; and detecting the discrete wavelengths with a detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
- New set of Claims (continued) -Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
providing a hand-held infrared spectrometer;
irradiating infrared radiation onto a sample (carpet) waste from an infrared radiation source in said hand-held infrared spectrometer;
selecting a plurality of discrete wavelengths from radiation reflected by the sample of waste (carpet) by utilizing a radiation selector in said hand-held infrared spectrometer, said step of selecting a plurality of discrete wavelengths comprising the substep of dispersing the reflected radiation utilizing a dispersing device and the substep of selecting a plurality of discrete wavelengths from the dispersed radiation; and detecting the discrete wavelengths with a detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
22. A method of discriminating between various types of post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
providing a hand-held infrared spectrometer;
irradiating infrared radiation having a plurality of predetermined wavelengths onto a sample of waste (carpet) from an infrared radiation source in said hand-held infrared spectrometer, said plurality of predetermined wavelengths being selected by dispersing a beam of infrared radiation utilizing a dispersing device and selecting a plurality of discrete wavelengths from the dispersed radiation; and - New set of Claims (continued) -detecting the discrete wavelengths with a detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
providing a hand-held infrared spectrometer;
irradiating infrared radiation having a plurality of predetermined wavelengths onto a sample of waste (carpet) from an infrared radiation source in said hand-held infrared spectrometer, said plurality of predetermined wavelengths being selected by dispersing a beam of infrared radiation utilizing a dispersing device and selecting a plurality of discrete wavelengths from the dispersed radiation; and - New set of Claims (continued) -detecting the discrete wavelengths with a detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
23. A method of discriminating between various types of post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
providing a hand-held infrared spectrometer;
irradiating infrared radiation onto a sample of waste from an infrared radiation source in said hand-held infrared spectrometer;
selecting a plurality of discrete wavelengths from radiation reflected by the sample of waste (carpet) by utilizing a radiation selector in said hand-held infrared spectrometer, said step of selecting a plurality of discrete wavelengths comprising the substep of filtering the reflected radiation to thereby allow radiation of a plurality of predetermined wavelengths to pass to a detector system provided in the hand-held infrared spectrometer; and detecting the discrete wavelengths with the detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
providing a hand-held infrared spectrometer;
irradiating infrared radiation onto a sample of waste from an infrared radiation source in said hand-held infrared spectrometer;
selecting a plurality of discrete wavelengths from radiation reflected by the sample of waste (carpet) by utilizing a radiation selector in said hand-held infrared spectrometer, said step of selecting a plurality of discrete wavelengths comprising the substep of filtering the reflected radiation to thereby allow radiation of a plurality of predetermined wavelengths to pass to a detector system provided in the hand-held infrared spectrometer; and detecting the discrete wavelengths with the detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of the waste (carpet).
24. A method of discriminating between various types of post consumer or post industrial waste carpet or Polyamide-6 and/or Polyamide-66 containing non-carpet waste, comprising the steps of:
- New set of Claims (continued) -providing a hand-held infrared spectrometer; irradiating infrared radiation having a plurality of predetermined wavelengths onto a sample of waste (carpet) from an infrared radiation source in said hand-held infrared spectrometer, said plurality of predetermined wavelengths being selected by filtering a beam of infrared radiation utilizing a plurality of filters; and detecting the discrete wavelengths with the detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of he waste (carpet).
- New set of Claims (continued) -providing a hand-held infrared spectrometer; irradiating infrared radiation having a plurality of predetermined wavelengths onto a sample of waste (carpet) from an infrared radiation source in said hand-held infrared spectrometer, said plurality of predetermined wavelengths being selected by filtering a beam of infrared radiation utilizing a plurality of filters; and detecting the discrete wavelengths with the detector provided in the hand-held infrared spectrometer, thereby utilizing said hand-held infrared spectrometer to ascertain the type of material of he waste (carpet).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL1000738 | 1995-07-06 | ||
| NL1000738A NL1000738C2 (en) | 1995-07-06 | 1995-07-06 | Infrared spectrometer. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2226095A1 true CA2226095A1 (en) | 1997-01-23 |
Family
ID=19761275
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002226095A Abandoned CA2226095A1 (en) | 1995-07-06 | 1996-07-05 | Method of identifying post consumer or post industrial waste carpet utilizing a hand-held infrared spectrometer |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0836705A1 (en) |
| JP (1) | JPH11508689A (en) |
| KR (1) | KR100460972B1 (en) |
| CN (1) | CN1221799C (en) |
| CA (1) | CA2226095A1 (en) |
| MX (1) | MX9800206A (en) |
| MY (1) | MY118331A (en) |
| NL (1) | NL1000738C2 (en) |
| TW (1) | TW298614B (en) |
| WO (1) | WO1997002481A1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6031233A (en) * | 1995-08-31 | 2000-02-29 | Infrared Fiber Systems, Inc. | Handheld infrared spectrometer |
| EP0847524A4 (en) * | 1995-08-31 | 1999-10-13 | Infrared Fiber Syst Inc | Handheld infrared spectrometer |
| NL1006686C2 (en) * | 1997-07-30 | 1999-02-02 | Tno | Method and device for sorting carpet or similar textile pieces. |
| DE19820861B4 (en) * | 1998-05-09 | 2004-09-16 | Bruker Axs Gmbh | Simultaneous X-ray fluorescence spectrometer |
| WO2000064871A1 (en) * | 1999-04-23 | 2000-11-02 | Dsm N.V. | Process for nylon depolymerization |
| DE10011254C2 (en) * | 2000-02-28 | 2003-08-28 | Gusa Mbh | Process for the identification of the pile of textile materials, in particular for the identification of PA 6 and PA 66 in carpets |
| JP4054854B2 (en) * | 2000-10-17 | 2008-03-05 | 独立行政法人農業・食品産業技術総合研究機構 | Analysis of liquid samples using near infrared spectroscopy |
| US8044354B2 (en) * | 2008-12-04 | 2011-10-25 | The Boeing Company | Method for classifying resins types in carbon fiber reinforced plastic materials using IR spectroscopy |
| CN102680416A (en) * | 2012-04-19 | 2012-09-19 | 江苏大学 | Method and device for fast detecting caffeine content of summer and autumn tea |
| JP6235886B2 (en) * | 2013-01-08 | 2017-11-22 | キヤノン株式会社 | Biological tissue image reconstruction method and apparatus, and image display apparatus using the biological tissue image |
| JP2016028229A (en) * | 2014-07-08 | 2016-02-25 | キヤノン株式会社 | Data processing apparatus, data display system having the same, sample information acquisition system, data processing method, program, and storage medium |
| JP2019219419A (en) * | 2014-07-08 | 2019-12-26 | キヤノン株式会社 | Sample information acquisition system, data display system including the same, sample information acquisition method, program, and storage medium |
| CN104535526A (en) * | 2014-12-17 | 2015-04-22 | 中国科学院长春光学精密机械与物理研究所 | Linear gradual filter type handheld intelligent spectrometer based on microcomputer Edison |
| CN109425588B (en) * | 2017-08-30 | 2022-01-11 | 广州讯动网络科技有限公司 | Handheld device, method and computer-readable storage medium for quickly distinguishing huanglongbing |
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|---|---|---|---|---|
| FR1034328A (en) * | 1951-03-22 | 1953-07-22 | Cie Radio Cinema | Apparatus for spectral chemical analyzes |
| US2823577A (en) * | 1951-08-10 | 1958-02-18 | Leeds & Northrup Co | Multiple slit spectrograph for direct reading spectrographic analysis |
| US3696247A (en) * | 1970-11-12 | 1972-10-03 | Lionel D Mcintosh | Vehicle exhaust emissions analyzer |
| GB1392379A (en) * | 1972-08-17 | 1975-04-30 | Rank Organisation Ltd | Analytical apparatus |
| US4043668A (en) * | 1975-03-24 | 1977-08-23 | California Institute Of Technology | Portable reflectance spectrometer |
| US4345840A (en) * | 1980-04-08 | 1982-08-24 | California Institute Of Technology | Method and apparatus for instantaneous band ratioing in a reflectance radiometer |
| JPS61120023A (en) * | 1984-11-15 | 1986-06-07 | Shimadzu Corp | Spectrophotometer |
-
1995
- 1995-07-06 NL NL1000738A patent/NL1000738C2/en not_active IP Right Cessation
-
1996
- 1996-07-05 CA CA002226095A patent/CA2226095A1/en not_active Abandoned
- 1996-07-05 EP EP96922283A patent/EP0836705A1/en not_active Ceased
- 1996-07-05 WO PCT/NL1996/000280 patent/WO1997002481A1/en active IP Right Grant
- 1996-07-05 KR KR10-1998-0700096A patent/KR100460972B1/en not_active IP Right Cessation
- 1996-07-05 MX MX9800206A patent/MX9800206A/en not_active IP Right Cessation
- 1996-07-05 CN CNB961966890A patent/CN1221799C/en not_active Expired - Fee Related
- 1996-07-05 JP JP9505031A patent/JPH11508689A/en not_active Ceased
- 1996-07-06 MY MYPI96002800A patent/MY118331A/en unknown
- 1996-07-15 TW TW085108557A patent/TW298614B/zh active
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11508689A (en) | 1999-07-27 |
| NL1000738C2 (en) | 1997-01-08 |
| TW298614B (en) | 1997-02-21 |
| MY118331A (en) | 2004-10-30 |
| CN1221799C (en) | 2005-10-05 |
| MX9800206A (en) | 1998-04-30 |
| EP0836705A1 (en) | 1998-04-22 |
| KR100460972B1 (en) | 2005-05-17 |
| CN1195402A (en) | 1998-10-07 |
| KR19990028796A (en) | 1999-04-15 |
| WO1997002481A1 (en) | 1997-01-23 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Discontinued |