Only a few years ago, aerosol cans had an almost standardized form.
Today, diverse can geometries and thin materials present new challenges
to automated visual control.
How fast is such an inspection process? The final consideration
is that the faster the inspection, the more suitable the
automated production process. In most cases, the camera is too
slow for modern production processes or can only be used for
small-sized products with acceptable accuracy but not for the full
range of aerosol can production. The camera used in the shape
control system is the world’s fastest 3D camera and inspection
can be performed at line speed during the production process.
Inspection results
The data gained by the shape control system could be used to
generate colorful, three-dimensional height profile images of the
can that are aesthetically pleasing but data-intensive and not very
efficient for an analysis in a fast running process. In the end,
only one question is relevant—is this can flawless or does it have
defects such as dents, grooves, holes or scratches? The software
behind the acquired data has to give the answer. As we know
from previous inspection methods, the process uses a reference
comparison to provide a final decision of can viability. Dimensional
height profiles are only available for the operator to gain
a better understanding of which defect has been detected and
where it occurred.
When products change,
inspection technology must follow
New aerosol can designs require new inspection methods. This
simple fact continuously instigates exciting developments and
solutions. Only a few years ago, aerosol cans had an almost standardized
form. Today, diverse can geometries and thin materials
present new challenges to automated visual control.
Two-dimensional inspection systems need to be compact and
comprehensive in order to detect a large variation of defect types.
For example, inspection systems inside the necking machine
should view the can top without any blind sectors and be able to
catch print defects on the shoulder, a split curl or dimensional
deviations.
The three-dimensional inspection of the can shape at the end
of the production process is an innovative approach and combines
the latest camera technology with new inspection concepts.
Shape control is an important step towards fully automated final
inspection for aerosol cans and must be a priority for all modern
production sites in the near future. SPRAY
Contact the authors: christiane.blasiuse@muehlbauer.de
or ralf.freiberger@muehlbauer.de
34 SPRAY January 2018