Patent ID: 7161151
Filing Date: 2007-01-09
Classification: G01N

Abstract:
1. A plastic material identifying method comprising: (i) a step of obtaining a first infrared absorption spectrum by irradiating infrared light of a predetermined wave number onto an item to be identified that contains a plastic material and measuring the intensity of the infrared light that is totally reflected by the item; and (ii) a step of identifying the plastic material contained in the item to be identified by matching the first infrared absorption spectrum with a group of infrared absorption spectra that have been measured for a predetermined group of materials; wherein the predetermined group of materials is a group of materials containing plastics; and each infrared absorption spectrum in the group of infrared absorption spectra is obtained by irradiating infrared light of a predetermined wave number onto each material included in the group of predetermined materials, and measuring the intensity of the infrared light that is totally reflected by the material; and matching is carried out by comparison between the first infrared absorption spectrum and each infrared absorption spectrum in the group of infrared absorption spectra in terms of presence or absence of a peak in a predetermined wave number range and by comparison between the first infrared absorption spectrum and each infrared absorption spectrum in the group of infrared absorption spectra in terms of a value obtained by dividing a highest peak intensity in a wave number range of 1,000 cm