Internal and external cleanliness of products

Product cleanliness (purity) testing is a very important element in the quality assessment of many components used in the automotive industry (and beyond). Such tests are carried out in a clean room of ISO 6 cleanliness class (according to ISO 14644) and the basic factors determining the purity of the test object are: mass of insoluble impurities, mass of soluble impurities, amount of insoluble impurities of a certain size and type of contamination. In the case of insoluble impurities, it is possible to divide them according to their nature: metallic, non-metallic and fibres, as well as by chemical composition. In order to determine these properties, an appropriate method of extracting pollutants is selected: shaking, pressure washing, ultrasonic techniques, washing on functional test benches reflecting the working parameters of the test object. The choice of the method depends on the characteristics of the test object and on the specified properties: internal/external/overall purity.
 
Separated pollutants are analyzed by the following methods:
 
  • weight – the mass of contamination
  • microscopic – the quantity and size of the contaminants
  • scanning electron microscopy – the composition of the impurities
  • infrared spectroscopy – the composition of the impurities
 

Devices

  • Zeiss Axio Imager M1m optical microscope, with motorised table and AxioVision software
  • SEM EVO 25MA Zeiss scanning electron microscope with Bruker EDX and EBSD detectors
  • FTIR Nicolet 6700 spectrometer
  • Nicolet iS50 FTIR spectrometer with microscope
  • PALL Cleanliness Cabinet PCC-41-R0220-NG2 automatic pressure washer
  • Ultrasonic cleaners
  • Analytical balances
  • Temperature chambers

Testing norms

  • ISO 16232 -2 (shaking),
  • ISO 16232-3 (pressure washing),
  • ISO 16232-4 (ultrasonic),
  • ISO 16232-5 (functional test bench),
  • ISO 16232-6 (weight analysis),
  • ISO 16232-7 (microscope analysis),
  • ISO 16232-8 (SEM analysis),
  • ISO 16232-10 (codification of the degree of contamination).
 

Testing norms from the industry and customers’ own norms

  • VDA 19, DBL 6516, GMW 16037, Volvo STD 107-0002, Scania STD 4189, NW 22-10-202, QV 11111, SAE J1726, PV 3347, DBL 6515, BWS 42001, Renault 34-07-012, Renault 34-07-025 and others.
Document No. Title/Description
ISO 16232-3 Standard Test Method for Simultaneous Thickness and Electrode Potential Determination of Individual Layers in Multilayer Nickel Deposit (STEP Test)
ISO 16232-4 Road vehicles - Cleanliness of components of fluid circuits - Part 4: Method of extraction of contaminants by ultrasonic techniques
ISO 16232-5 Road vehicles - Cleanliness of components of fluid circuits - Part 5: Method of extraction of contaminants on functional test bench
ISO 16232-6 Road vehicles - Cleanliness of components of fluid circuits - Part 6: Particle mass determination by gravimetric analysis
ISO 16232-7 Road vehicles - Cleanliness of components of fluid circuits - Part 7: Particle sizing and counting by microscopic analysis
ISO 16232-8 Road vehicles - Cleanliness of components of fluid circuits - Part 8: Particle nature determination by microscopic analysis
ISO 16232-10 Road vehicles - Cleanliness of components of fluid circuits - Part 10: Expression of results
ISO 16232-2 Road vehicles - Cleanliness of components of fluid circuits - Part 2: Method of extraction of contaminants by agitation