Abstract
A technique for inspecting the deterioration of plastics has been developed to enable the plastic chassis (ABS copolymer and high-impact polystyrene) of office automation appliances to be reclaimed. First, infrared spectra of degraded plastic samples were measured with a Fourier transform infrared spectrometer using the attenuated total reflection method. The ratio of C=O bond peak intensity to benzene ring peak intensity was found to correlate with the deterioration depth from the surface. This ratio was defined to be the degree of deterioration. Next, the strength of the samples of reclaimed plastic was tested, and it was found that the Izod impact value decreased as the blending ratio of degraded plastic increased. Equations determining conditions for classifying degraded plastic were derived using the relationship between degree of deterioration and deterioration depth, and between Izod impact value of reclaimed plastic and the blending ratio of degraded plastic. An example of classification condition was calculated using these equations. Three classifications were made for molding of blending virgin material, sandwich molding and thermal recycling. Finally, a plastic deterioration inspection appliance was produced and used to inspect the chassis of used personal computers. The results showed that the increase in the degree of deterioration with a number of years of use was greater for ABS copolymer than for high-impact polystyrene.
