Components and Assembly

© Fraunhofer IPA
Components and assembly

Whether crankshaft or gear block, filter element or screw – dirt particles can have devastating effects. The Fraunhofer IPA has been testing various components for many years and hence covers pollution causes of claims or, in the ideal case, prevents them. If the particle sources are suspected in the assembly environment, the experienced staff also support the optimisation of processes and production design.

Under the leadership of Fraunhofer IPA both the VDA Volume 19.1 valid guidelines for the testing of functionally relevant automotive parts and the guidelines published in the VDA Volume 19.2 for the cleanliness of the environment, logistics, personnel and assembly facilities have emerged.

Component cleanliness in the automotive industry is a technical quality characteristic that must be controlled and documented. The so-called residual dirt test must provide reliable data on product and process quality in order to base the associated investment decisions and quality measures on a solid foundation. The residual dirt analysis for functionally relevant automotive parts requires special expertise and laboratory equipment.


As an independent reference laboratory and head of the Policy Working Groups, we offer:

  • Standardized cleanliness analyses of parts and assemblies in accordance with the established standards
    • VDA Volume 19.1
    • DIN EN ISO 16232
    • as well as customer/company standards
  • Qualified testing specifications
  • Analyses of sediment traps and particulate stamps from the environmental monitoring or for the localisation of particle sources

Our laboratories also provide analysis for highly-clean or large components. After consultation you are welcome to pursue the examination of your components in our laboratory.


Liquid extraction

Due to the mostly internal or difficult to access functional areas of parts and components relevant particles must be cleaned from the areas concerned by means of liquid. To this end, we have a wide variety of methods and equipment available.

  • Extraction equipment for the process: Spraying, Rinsing, Shaking, Ultrasound
  • Variable Ultrasonic Equipment
  • Extraction systems for components up to 1m in length
  • Highly-clean extraction systems for clean components
  • If required, extraction by clean media


Air extraction

For a number of components such as electronics, extraction by liquid can result in a destructive test. The damage is particularly high for high-priced components. In addition, some tested components during manufacture or in their final use never come into contact with liquids and thus the question can be asked as to whether a test with liquids can deliver a meaningful result. In studies for the testing of optical, electronic and precision engineering composite systems, packaging materials, as well as car headlights, in which the removal of pollution particles is now performed with clean air pressure instead of the usual test liquid, there has been impressive evidence for the suitability of this new so-called air extraction. This process will be possible in the future in the context of the VDA Volume 19.1.



Thanks to the extensive analytical capabilities in the technical cleanliness laboratory, not only the quantitative determination of particle addition but also information such as elemental composition and the size of particles in three dimensions can be determined. Features of the analysis technique:

  • Five-digit analytical scales
  • Scanner for particle analysis
  • Light optical microscopes for automated particle analysis from 5 microns
  • Fluorescence microscope
  • Scanning electron microscopes for automated particle analysis of inorganic / metallic particles
  • Analysis of organic material, for example plastic particles by:
    • RAMAN spectroscopy
    • FTIR (Fourier transformations infrared spectrometer)
  • Micro-CT for 3D particle analysis
  • Correlative analysis between light microscopy and SEM-EDX systems

From consulting days with manufacturing inspections, staff awareness regarding protection of the product or sampling of a production line using particle traps and residual dirt analysis to cleanliness audits. For more than a quarter of a century, we have been looking for the proverbial needle in the haystack of a production area, in order to deal with urgent problems of cleanliness quality (process chain analysis).

We drew on this experience as leader of the industrial alliance »Assembly Cleanliness« during the making of »VDA 19.2 – Technical Cleanliness in Assembly«.

Initial Situation

  • Non-clean production and assembly conditions are the causes of faults of workmanship, malfunctions of the final product, scrap and rework as well as dissatisfied customers.
  • Meticulously clean components often fail to produce clean products.



  • The potential for error caused by impurities in the manufacturing process can have subtle and varied causes.
  • Possible causes range from the construction and operation of production facilities to the personnel, the logistics or even building technology.
  • Often the instinct, experience or special knowledge needed to get the disruptive impurities in the right places and costs under control is lacking.
  • Sometimes the necessary distance and an independent view (operational blindness) is also lacking.



  • Finding risks and potentials in the process chain
  • Independent sparring partners for sensitive and strategic issues and investment decisions
  • Examinations and measurements to determine the cleanliness of manufacturing facilities and production environments; e.g. cleaning validation, particulate traps
  • Training and sensitisation of managers and employees
  • Cleanliness oriented design of production facilities and jobs
  • Planning of product and process adapted cleanrooms

We educate

We provide the knowledge on VDA Volume 19 and 19.2 in our seminars at the Stuttgart Fraunhofer Institute Centre but also to your business via tailored in-house training on site.