Machine vision systems automatically detect chocolate residues and contaminants and prompt the removal of unclean moulds. Given the limited installation space in many cases, Berlin-based machine vision specialist Bi-Ber manufactures modular systems in different configurations to provide flexible solutions.
The times of individually manufactured mechanical stamps to check the state of moulds are over. Today, inspection of all kinds of moulds is the domain of machine vision technology. Instead of long changeover times for the installation of mould-specific stamps, various shapes and sizes are now stored in the system memory, which can be called up instantly. Moulds can be automatically identified, for example via RFID codes. New moulds can be quickly added via teach-in.
Commercially available systems for this task come with image sensors of various kinds, although colour cameras are best suited to check empty moulds. They achieve excellent results in detecting brightness and colour differences between mould and possible contaminants. Combining megapixel cameras with powerful software, Bi-Ber manages to identify dirt and foreign objects as small as 1 mm². This clearly surpasses industry requirements which allow for tolerances up to 5 mm², depending on the manufacturer. The system captures up to 60 moulds per minute.
Bi-Ber configures such inline inspection systems as fully operational software and hardware solutions. All components are mounted in a compact stainless-steel cabinet, which is placed directly over the transfer system. Integrated service doors allow line operators to access the process. Foreign objects as potential contaminants are ruled out by design, since there are no user controls and no loose parts over the moulds. The imaging and lighting components are shielded against the empty moulds by a protective pane. The panel PC with a touch screen for controlling the system is positioned on the side of the transfer system.
Latest-generation inspection systems from Bi-Ber feature various improvements. They can be equipped with two cameras instead of just one. This allows for shorter working distances and a reduced height. New benefits also include greater flexibility, because two cameras can monitor up to 1,050 mm wide moulds. All segments, all the way to the edges, will be captured with only small distortions. Using LED technology instead of fluorescent tubes also saves space. Moreover, LEDs are very low-maintenance.
A compact design is a concern to many system builders. Consequently, Bi-Ber now manufactures its empty mould check systems in different configurations and sizes. The standard design for 640 mm wide moulds is 1,370 mm high and 600 mm long in transfer direction. Alternatively, the switchgear and panel PC can be installed in a separate control cabinet. The remaining camera and lighting enclosure has a cross section of 200 mm x 162 mm (width depending on mould sizes). It is suitable for extremely flexible integration even if installation space is tightly constrained.
The compact enclosure does not require a mounting surface that matches the full size of the base but can instead be attached with custom mounting brackets. Instead of service doors, it features inspection flaps. The two-part design includes a control cabinet that is about 1,000 mm tall and can be positioned freely, for example next to the transfer line.
