Automated matting of shiny and transparent parts
Automation is progressing at breath-taking speed. Costs have to be lowered and capacities increased. In automobile manufacture in particular, this trend is clearly visible. And in optical measurement technology, too, processes are increasingly being automated. In spatially defined scanning boxes, 3D scanners mounted on robot arms rapidly and accurately digitalise the components in an extremely short space of time. However, automated measurement meets its limits when it is difficult or impossible to measure the dimensions of the components owing to their shape, size or material characteristics. These include transparent, reflective and uneven surfaces which hinder the entire optical measuring process and – if it is possible at all – often lead to distorted measurement results.
Problematic: scanning of transparent and reflective surfaces
With transparent surfaces, the light of the scanner shines through the surface which means that the surface structure cannot be captured.
Similarly, with reflective surfaces, the scanner is also not able to scan the surfaces. Here, the ray of light is reflected not in a diffuse, but focused manner.
A further problem comes from components with pronounced uneven areas. The walls of recesses cause reflections and lead to incorrect representations.
Matting of the surfaces
Transparent and reflective surfaces can be matted using scanning sprays. Using a newly developed spray, the AESUB scanning spray, a matt, white and homogeneous coating is generated in just a few seconds. As a result, the component’s surface become impervious to light and no longer reflects, which means that the objects can be scanned. Because the AESUB spray automatically sublimates, cleaning of the components after the scanning process – something which is time-consuming and/or costly – is no longer necessary.
Automated spraying
Using spray robots, the measurement of problematic surfaces is automated further: the matting is directly integrated into the automated digitalisation process. To do this, the component is arranged in the measuring cell and/or scanning box for the measuring process. Via a spraying mechanism, the
AESUB green scanning spray is fed into the robot arm. The robot arm travels along the path programmed for the digitalisation and, in the process, evenly sprays the component to be measured with the AESUB scanning spray. Depending on the component size, the entire spraying process lasts approx. 20 - 60 seconds. A white, homogeneous layer approx. 10 µm thick is generated, onto which reference points can also be applied without a problem. Subsequently, the digitalisation begins with a second robot arm on which the scanner is mounted and which travels along the same contours as the spray robot previously.
Automatically sublimating spray, no contamination of the measuring environment, no cleaning
The AESUB spray is free from pigments – such as harmful titanium dioxide – which are frequently used in conventional scanning sprays. Pigment-containing sprays inevitably cause contamination of the measuring environment. They put the user at risk and damage the component and also the sensitive measuring equipment. Because the AESUB spray evaporates automatically, no cleaning of the component or measuring environment is required. Unlike the pigment-containing sprays, the coating applied with AESUB sprays is touch-dry, which hugely simplifies the handling of the sprayed component.