Empty can inspection: top performance due to depth of field

The new HEUFT canLine upholds the productivity of filling lines for drinks cans as well as the safety and quality of the end product.

Compact, light, unbreakable, gas and light proof, good for pasteurising, can be quickly cooled and recycled any number of times:  there are many reasons which speak in favour of the can for packaging  drinks.  Thus it sells well.  Annual growth rates were up to 35% worldwide recently and this year the magic mark of 300 billion will be exceeded.
The upward trend is continuing.  Consumers regard the robust lightweight, the wall of which is thinner than a human hair, highly for reasons of convenience.  Logistics and trade industries appreciate the little amount of space required.  And the producers of beer, soft drinks, wine products and alcoholic mixed drinks are pleased with, among other things, high filling performances of far more than 100,000 containers per hour provided that the filling process is running smoothly without jams and standstills.  For this a new development for inspecting empty cans makes a fundamental contribution:  the HEUFT canLine identifies misshapen or damaged containers and removes them before they can cause obstructions in the filler / closer system and thwart the efficiency and productivity of the complete line.  At the same time the system detects and removes cans which are soiled, contaminated with foreign objects and which could possibly have leaks thus sustainably safeguarding the integrity and quality of the final product.


Preventing obstructions in the closer


The compact HEUFT canLine examines the base, the inner sidewalls and the flanged edge in the finish area of the empty can which is still unsealed from above with a single camera.  The optics system has such a depth of field that faults in all these areas become clearly visible in the high–resolution images.  Specially arranged LED strobes make sure that the containers are illuminated without reflections and shadows, the new HEUFT reflexx² high–performance image processing system, with greatly increased computing power, resolution and colour depth, provides more contrast and the optimised filter and analysis technologies ensure a new quality of detection reliability.  Minute faults are precisely detected even along high–speed lines.  Deformations, indentations and damage, which could result in cans not being sealed at all or not being tightly sealed, are tracked down and rejected by the flanged edge inspection.  This prevents possible closure obstructions and protects the microbiological purity of the drink.  The base and inner wall inspection identifies dents, bumps, dirt and foreign objects which are potentially dangerous to health.
The HEUFT canLine examines the outer appearance of the cans with the optionally integrable HEUFT FinalView technology for an optical 360 degree inspection of the sidewall.  In this way scratched, misprinted and non–brand cans can be tracked down and sorted out even before they are filled.  Brand and format changes are carried out within a very short time without any mechanical changeover work:  the height and position of the detection units as well as the passage width of the guide rails in the inspection area automatically adapt themselves to the changed production program at the touch of a button.  Consistent monitoring ensures that each empty can is inspected and each can identified as being faulty is rejected.


This new development attracted a great deal of interest during its debut at the Brau Beviale 2011 exhibition.  The first successful installations prove that the HEUFT canLine is highly efficient in practice and effectively prevents jams in the filler feed by removing containers which cannot be closed from the line in good time.  This has a positive effect on the efficiency and productivity of the complete can filling line.