Imaging Inline Measuring System Detects Contamination On 3D Components

2023 Author: Hannah Pearcy | [email protected]. Last modified: 2023-08-25 03:36

The smallest things can have a big impact: For example, tiny dirt particles that stick to their surface during the manufacture of components. Take the oil pan, for example: If oil contamination is located where the sealant is to be applied later, the seal will not hold at this point - the pan will probably be permeable here. So far it has not been technically possible to check all components for residual contamination. Only random samples are taken, which are time-consuming on the one hand, and on the other hand do not allow a statement to be made as to where the contamination was located on the component.

Spatially resolved inline measurement: 100% quality

In the future, manufacturing companies can play it safe when it comes to contamination. This is made possible by the inline measuring system F-Scanner, which researchers at the Fraunhofer Institute for Physical Measurement Techniques IPM in Freiburg have developed. "With the scanner, we can not only measure every single metallic component inline - i.e. directly during production, without additional time - but also tell exactly in which area there are dirt particles," explains Andreas Hofmann, business unit manager for production control at Fraunhofer IPM. "We are able to identify even the smallest contaminants or oil films of less than ten milligrams per square meter."

Oil films, shavings and the like reveal themselves through their fluorescence

The principle: While the oil sumps are being transported on a conveyor belt from A to B, a UV laser illuminates a small punctiform area of the component. If there are oil, residues of organic cleaning substances or fibers on the surface, they send back a visible fluorescent light, quasi in response to the UV light of the laser. This is exactly the light that a detector picks up; it is blind to all other wavelengths. It can therefore detect the fluorescence signals of the contaminants very sensitively. The metallic component itself does not send back fluorescent rays. A scanner ensures that the laser dot rushes over the surface very quickly, thus scanning it point by point. The laser beam scans over the object about 200 times per second. As a result, the quality manager gets a picturewhich shows exactly whether and where dirt particles or oil films are present.

The F-Scanner can even identify the actually non-fluorescent component chips that have stuck to the test object from preprocessing steps. "Since the components are cleaned with water or air after the pre-processing, only those chips stick that are contaminated with oil or other substances - and these substances fluoresce," says Hofmann.

Local resolution and speed can be adapted to production

The researchers adapt the spatial resolution of the system and the speed to the respective conditions, such as the clock rate in production. The use of the F scanner is not limited to metallic components alone - however, specific tests are required for other materials. (yup)