In order to test and evaluate the geometry of extruded profiles the Keyence laser profile measurement device was used for which a special construction with cabinet was build. The extruded plastic profiles were continuously measured with the laser profile measurement device for several days and the results showed that the geometry deviation on extruded profiles was constantly inside the tolerance range. This clearly showed that the extrusion production of plastic profiles was stable enough from geometrical point of view and that investment into expensive laser profile equipment in fact is not necessary neither justified. Picture 1 shoes the trials with Keyence laser profile measurement device for profile geometry inspection.
For testing and evaluating the surface quality of extruded profiles, ISOKON used two vision inspection cameras, one of which was mounted and positioned from top-down and the second one was positioned from the side on the same special construction with cabinet that was built also for laser profile device. In collaboration with AIMEN, ISOKON had to first properly calibrate entire vision system, detect the initial defects and conduct several trials to improve the detection ratio.
During these trials the vision system was able to spot very small defects like black dots, small voids, water drops etc. and ISOKON moved on to set-up a detection algorithm, which was further improved with AIMENs help in order to ignore small defects like water drops that don’t affect the surface quality and instead sharpened the focus on spotting the real defects like black dots and small voids.
This was successfully achieved, as seen from the images, where defects are spotted in real time and marked with yellow squares. Currently ISOKON is continuing with the detection algorithm trials improvement in order to increase the vision systems reliability of detecting and marking the surface defects on different extruded plastic profiles in order to have a more robust detection algorithm. Picture 2 shows the trials with vision system for surface quality inspection