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Key Features |
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- smaller in size (1/40)
- faster response time (1/20)
- a longer illumination life (33 times)
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Alternative Method for
Plastic Sorting |
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In a study recently completed by IDEC, a
prototype sensor featuring InGaAsP laser diodes on three
different wavelengths was successful in identifying
transparent PET (polyethylene terephthalate), PVC (polyvinyl
chloride) and PS (polystyrene) plastic.
The primary intended application for such a sensor is the
recycling industry. Our society has promoted mass production
at the expense of the environment, but finite resources
require the circulation and recycling of parts in pre-consumer
as well as post-consumer markets. Plastic packaging and
components play a major part in manufacturing and recycling.
This new sensor will make smaller-scale, pre-consumer
recycling of goods much more feasible, and will offer more
options to larger facilities using current recycling methods.
Most PVC and PET plastics can be sorted visually by operators,
but there is no guarantee of accuracy, and other plastics
cannot be sorted this way. At present, automated plastic
identification systems use near-infrared spectroscopic
analysis, which, while highly accurate, requires large,
complicated equipment which is expensive to install and
maintain. The use of a small, low-cost sensor would help
create an easy-to-use recycling system in more modest
environments.
Optical transmittance can be used to identify different types
of plastics, and our studies showed that sequential radiation
(originally developed for full-color sensing technology) can
be used to send signals to an oscilloscope and thereby
differentiate between types of plastic.
Results of the sensor trials were comparable to results with a
standard spectrometer. But this sensor is smaller in size
(1/40), has a faster response time (1/20) and a longer
illumination life (33 times), and can be manufactured and
installed at a significantly lower cost.
IDEC will continue to research and refine plans for the new
plastic sensor in the coming year, and plans to have a
complete product offering in the fourth quarter of 2002. |
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