Project goal:

A large number of different types of particles are present in the environment (biogenic particles, eroded soil materials, industrial or volcanic emissions, desert sand or salt crystals in maritime regions, and burn-off residues). For sustainable product development and product qualification, the property profile of the dusts must be known and the effect quantified with regard to possible product stress.
The effect of particulate materials on a wide range of products is investigated in test chambers (e.g. IP protection class tests). The aim is to determine a property-effect function with regard to product functionality and service life, taking into account transport behaviour, climate, material pairing, electrical properties and reliability.

Main areas of work:

- Incidence and properties of the particles in the physical environment
- Simulation of the property profiles with test dusts
- Design of test chambers
- Characterization of the effect of particles

 

At Nuremberg Tech, we are investigating external influences on the resistance of particle fractions.

Test chambers at Fraunhofer ICT, Arizona test dust

DETERMINING THE RESISTANCE OF PARTICLE FRACTIONS

Resistance or electrical conductivity is an important product property in addition to often discussed particle characteristics such as particle size distribution, specific surface area, density, and polymorphism. When testing the impermeability of electronic devices or components, the penetration of particles can lead to bridging as a result of the dust layers deposited inside, which, depending on the humidity, may possibly cause short-circuit reactions.

 

Objective

Investigation of various powders and influencing factors that encourage unwanted current flow. The influence of the particle size, sample mass, and relative humidity is investigated in particular.

Sample pre-treatment

  • Particle size determination: Laser diffraction spectrometry
  • Compression: Jolting volumeter

Measurement

  • TeraOhmmeter
  • Shielding chamber
  • Powder electrode

Literature

U. Teipel, A. Ditts, H. Winter, J. Cäsar
Charakterisierung von Prüfstäuben
VFI: Versuchs- und Forschungsingenieur 40 (2007) 2, 28 - 33

U. Teipel, H: Winter, J. Cäsar
Produktqualifikation durch Staubprüfung: Charakterisierung von Prüfstäuben
Gefahrstoffe - Reinhaltung der Luft 69 (2009) 1/2, 43 - 48

U. Teipel, J. Cäsar, 7th-semester students of process engineering at the Nuremberg Institute of Technology
Wirkung von Partikeln – Produktqualifikation durch Staubprüfung
Proc. 38th Annual Conference of the Society for Environmental Engineering (GUS), Blankenloch, 2009, 179 - 194


Further information