Method of determining type of plastics
US5512752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1994 |
| Grant date | Apr 30, 1996 |
| Priority date | — |
| Expiry date | Jan 13, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/3563
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is provided for determining the type of an unknown plastic including the steps of irradiating an unknown plastic with near-infrared rays within a prescribed measurement wavelength range to measure an absorption spectrum, calculating the differential spectrum of the unknown plastic, measuring the differential spectrum at prescribed measurement intervals, determining the class of the differential spectrum by determining whether each measurement is on a plus-side, a minus-side or any other side, comparing the class of the differential spectrum measurement at each interval with a class of a differential spectrum measurement previously determined for each of the intervals over the range for a plurality of plastics of known types, and determining the type of the unknown plastic as the plastic having the highest class agreement ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.