TECHNICAL CLEANLINESS
Technische Sauberkeit
Technische Sauberkeit
The basis for the methods for determining the technical cleanliness are the volumes VDA 19 and ISO 16232, parts 1-10.
- VDA 19: 2004: Testing of technical cleanliness - Particle contamination of functionally relevant automotive parts
- VDA 19-2: 2010: Technical cleanliness in the assembly
- ISO 16232, Parts 1-10: Road vehicles - Cleanliness of components for fluid systems
The cleanliness test is basically a sampling test. A test of this property by means of testing machines is not possible.
To achieve a requirement for the technical cleanliness of components, a holistic consideration of the processes, even after the added value of the individual product, is essential. These include, for example, processes such as sorting, packaging, transport and assembly. These are to be agreed with regard to the requirements for technical cleanliness between customer and supplier.
The technical cleanliness test is an indirect test requiring a sampling step. For the relevant surfaces of critical parts are often located in the interior of pipes, ducts, housings, tanks, pumps, valves or similar components in which fluids are often conveyed, which can transport particles to sensitive areas of systems. These inner surfaces are usually not accessible for direct tactile or optical inspection. In addition, most of the surfaces are not suitable for optical inspection due to material, roughness, and lack of contrast with the particle contaminants.
For this reason, extractions are first necessary for analyzes of technical cleanliness. In the first step, the particles are cleaned off the test part via a laboratory cleaning step. Subsequently, the filtration of the complete extraction medium and the separation of the particles extracted from the component are carried out on an analysis filter, which is then the actual analysis - usually under the microscope - is supplied.
Cleaning the component: Possible test cleaning methods are spraying, ultrasonic, shaking or rinsing. The procedure is often specified by the customer. The suitability of the test cleaning procedure must be validated using the decay curve (see VDA 19 and ISO 16232).
Determination of the blank value: The blank value represents the total value of impurities not originating from the component. It is the result of a complete test without components. The permissible blank value must first be determined / determined. It must usually not exceed 10% of the required value.
Evaluation: Gravimetric, where the particle mass (in mg) per area (converted to 1000 cm2) and / or per component is determined. In the latter case, the component size must also be taken into account.
Granulometric (morphology, particle size), here the number and size (length, width) of the particles (in m) per component or per area (converted to 1000 cm2) are determined.
Examples of metallic (shiny metallic) particles: machining chips, metallic blasting agent residues, metal residues, zinc flakes, etc. "A clear identification can only be made on the basis of further analysis, for example by means of scanning electron microscopy with micro-area analysis."
Examples of non-metallic (non-metallic shiny) particles: lacquer, plastic, non-metallic blast media residues, abrasive residues, etc.
Definition of Fiber Detection: A fiber is considered as such if its stretched length is at least 20 times the area circled. By definition, fibers are not wider than 50 m by definition.
For the purposes of the directive, a distinction is made between metallic and non-metallic particles. A definite distinction between the two types of particles is not possible by light microscopy. However, by means of polarization-optical effects with a relative probability, a metallic particle ("shiny metallic") can be identified.
Standards
VDA 19-Teil 2
ISO 16232
John Deere JDS G169
Steyr Werknorm WN0004
Amazone Werknorm
Liebherr Werknorm TLV 23028
Daimler VAM00328
Borg Warner Turbo Systems BWS 42001
Behr GN AR.01117
Audi PV 3336
Bosch PV 1 279 921 533
BMW QV 11 111
Continental GQR 10098907
Daimler VAM00328
Deutz PV 01620033
Deutscher Schraubenverband Richtlinie
Fiat FPI.MAN050
GIMA GSP 015
MAGNA POWERTRAIN S40 029
Mercedes Benz DBL 4953
Porsche PTL 14045
SAE J2045
Schaeffler Technologies S 252001-2
Seat S.A. PV 3336
Siemens SN 52820
Skoda Auto a.s. PV 3336
Thomas WN 0135
Thyssen Krupp Bilstein Suspension WNB -881 D
Verband der chemischen Industrie VPA 5
Volvo STD 107-0002
VW PV 3336
ZF Friedrichshafen AG WN 70/13
ZF Lenksysteme ZFLS NS 5-1
ZF Sachs AG ZFN 5008-1
Wacker Neuson WN 71/E
