Apparatus for automatically inspecting powdery products for the presence

Abstract

An apparatus for automatically and continuously inspecting a powdery product for the presence of foreign substances as contaminants, which permits highly precise inspection of powdery products, comprises static charge eliminator 10 for eliminating electrostatic charges generated on a powdery sample supplied to the apparatus; hopper 41 for receiving and storing the powdery sample whose electrostatic charges have been eliminated and dropped onto the hopper through static charge eliminator 10; conveyor 42 for conveying the powdery sample, as a subject to be photographed, discharged from hopper 41 and spread over conveyor 42 in the form of a layer having a uniform thickness; and video camera 43 for photographing, over a predetermined visual field, the powdery sample on the subject-conveyor. Images taken by video camera 43 do not include those originated from dark spots due to unevenness of the powdery sample distribution, but includes only those originated from foreign substances even when inspecting a powdery sample which is liable to be electrically charged such as a vinyl chloride resin, since the powdery sample is not agglomerated.