Method for the routine identification of plastics
First Claim
1. An infrared spectroscopy method for the routine identification of a plastic component in refuse for the purpose of recycling, comprising the steps of:
- a) taking an IR reflection spectrum of the plastic component in the near infrared range (NIR) of wave numbers between 4,000 and 10,000 cm-1 ;
b) comparing the spectrum of step a) to reference spectra;
c) selecting the plastic component if steps a) and b) do not lead to a unique identification;
d) guiding light from a mid-infrared range (MIR) source having a wave number range between 400 and 4000 cm-1 through a Fourier transform infrared (FTIR) spectrometer;
e) focussing the light of step d) onto a surface region of the plastic component selected in step c);
f) passing light reflected from the surface region through onto a mid-infrared detector;
g) recording an MIR spectrum of the selected plastic component;
h) comparing the MIR spectrum to a set of reference spectra having a plurality of member spectra, each member spectrum corresponding to a class of plastic materials; and
i) correlating the selected plastic component to one member spectrum of one class of plastic materials.
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Accused Products
Abstract
A method for routine identification of materials of plastic components with the assistance of infrared spectroscopy with which an infrared reflection spectrum is taken from the surface of a plastic component to be investigated and compared to a set of reference spectra, whereby the material of the plastic component under investigation is correlated to a class of plastic materials represented by one of the reference spectrum, is characterized in that the plastic component under investigation is positioned with the assistance of a video device (25, 26) and in that the infrared reflection spectrum is recorded in the range of the mid-infrared (MIR) in a wave length region between 400 and 4,000 cm-1. In this fashion even plastics which, for example, are filled with carbon can be routinely identified. It is preferred when the first derivative of the recorded IR spectrum with respect to wave number is taken and compared to the first derivative of the IR spectra of the reference spectra.
76 Citations
21 Claims
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1. An infrared spectroscopy method for the routine identification of a plastic component in refuse for the purpose of recycling, comprising the steps of:
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a) taking an IR reflection spectrum of the plastic component in the near infrared range (NIR) of wave numbers between 4,000 and 10,000 cm-1 ; b) comparing the spectrum of step a) to reference spectra; c) selecting the plastic component if steps a) and b) do not lead to a unique identification; d) guiding light from a mid-infrared range (MIR) source having a wave number range between 400 and 4000 cm-1 through a Fourier transform infrared (FTIR) spectrometer; e) focussing the light of step d) onto a surface region of the plastic component selected in step c); f) passing light reflected from the surface region through onto a mid-infrared detector; g) recording an MIR spectrum of the selected plastic component; h) comparing the MIR spectrum to a set of reference spectra having a plurality of member spectra, each member spectrum corresponding to a class of plastic materials; and i) correlating the selected plastic component to one member spectrum of one class of plastic materials. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. An infrared spectroscopy method for the routine identification of a plastic component in refuse for the purpose of recycling comprising the steps of:
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a) taking an IR reflection spectrum of the plastic component in the near infrared range (NIR) of wave numbers between 4,000 and 10,000 cm-1 ; b) comparing the spectrum of step a) to reference spectra; c) selecting the plastic component if steps a) and b) do not lead to a unique identification; d) guiding light from a mid-infrared range (MIR) source having a wave number range between 400 and 4000 cm-1 through a Fourier transform infrared (FTIR) spectrometer; e) focussing the light of step d) as a first light beam through a first MIR transparent window in a direction perpendicular to a plane of the first window onto a surface region of the plastic component selected in step c); f) passing light reflected from the surface region as a second light beam through a second MIR transparent window in a direction perpendicular to a plane of the second window onto a mid-infrared detector within the FTIR spectrometer, the first and second light beams having an opening angle between 5° and
30°
;g) recording an MIR spectrum of the selected plastic component; h) comparing the MIR spectrum to a set of reference spectra having a plurality of member spectra, each member spectrum corresponding to a class of plastic materials; and i) correlating the selected plastic component to one member spectrum of one class of plastic materials.
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21. An infrared spectroscopy method for the routine identification of a plastic component in refuse for the purpose of recycling comprising the steps of:
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a) taking an IR reflection spectrum of the plastic component in the near infrared range (NIR) of wave numbers between 4,000 and 10,000 cm-1 ; b) comparing the spectrum of step a) to reference spectra; c) selecting the plastic component if steps a) and b) do not lead to a unique identification; d) positioning the selected plastic component with a video device, the video device comprising an endoscope and video camera; e) guiding light from a mid-infrared range (MIR) source having a wave number range between 400 and 4000 cm-1 through a Fourier transform infrared (FTIR) spectrometer; f) focussing the light of step d) as a first light beam through a first MIR transparent window in a direction perpendicular to a plane of the first window onto a surface region of the plastic component selected in step c); g) passing light reflected from the surface region as a second light beam through a second MIR transparent window in a direction perpendicular to a plane of the second window onto a mid-infrared detector within the FTIR spectrometer, the first and second light beams having an opening angle between 5° and
30°
;h) recording an MIR spectrum of the selected plastic component; i) comparing the MIR spectrum to a set of reference spectra having a plurality of member spectra, each member spectrum corresponding to a class of plastic materials; and j) correlating the selected plastic component to one member of one class of plastic materials.
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Specification