DEVICE AND METHOD FOR DISCRIMINATING PLASTIC

PROBLEM TO BE SOLVED: To provide a plastic discrimination technique which enables the convenient discrimination of polystyrene (PS) and acrylonitrile butadiene styrene (ABS). SOLUTION: A device 1A for discriminating plastic includes semiconductor light-emitting elements 2, 3 capable of irradiating an object 4 to be discriminated with a first detection light L1 with a wavelength of 1,141 nm and a second detection light L2 with a wavelength of 1,205 nm, and the method for discriminating plastic has the steps of irradiating the first detection light L1 using the semiconductor light-emitting element 2 and the second detection light L2 using the semiconductor light-emitting element 3, receiving the light reflected from the object 4 to be discriminated by a light-receiving element 5 which is irradiated with the first and the second detection light L1, L2, and measuring each reflection factor of the object 4 for the first and the second light L1, L2. Also, the method has the step of discriminating whether a plastic type making the object 4 is polystyrene (PS) or acrylonitrile butadiene styrene (ABS) by determining the difference in reflection factor between the light L1 and L2 and comparing the magnitude of this difference value and predetermined threshold values. Thus, PS and ABS can be discriminated precisely and conveniently. COPYRIGHT: (C)2009,JPO&INPIT