A surface inspection technique for continuously extruded cylindrical products

The objective of this paper is to provide a brief overview of various inspection methodologies for continuously extruded products, such as wire, cable and optical fibres, and to describe the implementation of a practical surface inspection technique. The main feature of the developed system is the use of a conic reflector arrangement to collect light scattered from a cylindrical surface. Illumination is supplied by optical fibres, strategically positioned around the cone, to provide full circumferential lighting. The inspection arrangement was implemented and tested in an industrial environment and effectively detected defects, such as blisters on wire (of diameters 0.2 mm to 3 mm), at a speed of up to .