- Foreign debris in the pocket (metallic, non metallic, bugs etc.).
- Missing tablets.
- Wrong shape tablets.
- Tablet’s position.
- Cracked tablets.
- Scratched or broken tablets.
- Pinhole detection on the PVDC foil.
- Print defects.
- Hair or fibers sealed between the PVDC and the aluminum foils.
- Foreign objects sealed between the PVDC and the aluminum foils.
- Blister incomplete cutting.
- Print defects such as embossing.
- Scratched or dirty pockets. (under development)
- Deformed pockets. (under development)
- Torn pockets. (under development)
The automatic blister (32x84mm) inspection machine consists of a regular speed blister feeder that loads the blisters on a conveyor that distributes them on 2 other sideline conveyors bringing the blisters along the different control stations. Both sides of the blister are inspected.
Once the inspection is completed, rejects are segregated and collected at a waste station. All control stations are connected to the machinery bearing structure in such a way that line operator’s access meets all safety and cleaning requirements. A machine management PLC operates the machine and manages input and output signals from the different control stations and handle the rejects station. The complete machine is GMP compliant.
There are four Vision Inspection Stations
Station 1 inspects the blister from the pocket side. The lighting system consists of white high luminosity leds (for stability and life-span) combined with a dedicated light diffuser that sheds homogenous and diffused light on the object under inspection. The camera is positioned vertically above the blister, at a distance of 200 mm from bliste level, which produces a framing field of 90×70 mm. For performance purposes, it uses a color, high resolution (1600×1200 pixels) camera.
Station 2 inspects pocket deformation and detecting ripped pockets, using light reflection. The white led illuminator projects light onto the blister under inspection, from an angle of 45°. The camera that frames the blister is also positioned at 45° with respect to the reference perpendicular, so that the light it receives comes from the most external pocket area.
Station 3 inspects the print on the side of the aluminum cover. The visual configuration is similar to the S1 Station system, but here the 1600×1200 pixel resolution camera is black and white, since no relevant color detail is to be examined. For Print defects the lighting system has to cater with the highly reflecting aluminum foil surface affecting control quality. This same camera will also carry out the pocket sealing inspection
Station 4 inspects the lateral embossed type of printing. The visual configuration is similar to the S2 Station system; here the 640×480 pixels resolution camera is black and white.