Causes and consequences of film type contaminats
Proper parts cleaning is becoming more and more relevant for many fields of industry. The verification of the cleaning result as well as the efficiency of cleaning are increasingly relevant. Whereas generally applicable methods for the detection of particular contamination have been established for some time, no adequate methods have existed for film-type contaminants so far.
In order to produce a flawless product, the parts are cleaned to achieve clean surfaces for subsequent processes and flawless finished products. The degree of cleanliness regarding film-type contaminants, however, is often not further specified due to the lack of suitable measuring equipment and process reliability. This means, that there is no certainty with regard to the efficiency of cleaning and the remaining contaminations. These, however, may vary from batch to batch despite an unchanged cleaning process. The reason for this is the use of different production aids at the suppliers and in the own production, which react differently on the type of cleaning, the used cleaning agent and the cleaning parameters.
What are chemical-film-type contaminants?
Chemical-film-type contaminants are thin, continuous (non-particular) films of undesirable, external substances partially or completely covering parts surfaces.
Origin and examples of chemical-film-type contaminants:
By means of a standardised process chain, we have listed possible sources of contamination, which should not be underestimated. Parts can get contaminated all along the process chain, starting from the goods receipt to production, cleaning and finishing to the shipping of goods and the selection of packaging.
What are the consequences of film-type contaminants?
Film-type contaminants endanger many subsequent processes and, thus, also the final product quality. Possible consequences may be, among others:
- coating defects and, thus, optical defects, which may impair the functionality (corrision-resistance, mounting ease, etc.)
- contamination of processing equipment, e.g. failure of optical components
- negative influence on the quality of joining processes, such as defective weld seams
- in case of medical technology: cytotoxic effects or insufficient biocompatibility of implants, instrument, etc.
- restriction of the service life of sensitive components
- outgassing, which can have a negative impact on the stability of vacuum based processes
- deteriorated characteristics of optical components (e.g. resolution of optical systems)
In order to minimise or prevent these consequences, it is necessary to check the parts cleanliness during the entire process chain by means of VIDAM®.
