Analysis of Contaminant Films
The cleanliness of components is of great importance in many branches of industry. For e.g. adhesive and joining processes, painting and many other coating processes require clean surfaces in order to obtain perfect results on various substrates such as metals, polymers, glasses or ceramics. Despite state-of-the-art production processes and numerous protective measures to ensure cleanliness, production-related contamination and contamination on surfaces in production often cannot be completely avoided. In the past few years, mainly particulate contaminations from the production processes have been considered. Today, contaminant films have come into focus. Contaminant films arise, for example, from residues of media from production such as oils, greases or cooling lubricants, as well as from the use of other operating aids. Passivation and corrosion protection layers can also be mentioned here as contaminant films. In many cases it is possible to eliminate the problem of contaminant films with simple cleaning steps. However, it can also happen that the cleaning process itself contaminates components and surfaces. Surfactants and additives from the cleaning agents used in the cleaning process can lead to coating and adhesive problems in the next step. Optical inspection and the use of test colors in the laboratories are established methods for controlling cleaning processes. However, if there are persistent particles or if there is evidence of contaminant films, more detailed laboratory analyses are needed to identify possible sources of contamination. In the Tascon laboratory you will find a variety of methods for the analysis of contaminant films. Depending on the exact damage pattern, the use of techniques such as SEM / EDX, FTIR or ToF-SIMS is helpful here. The following example will demonstrate the analysis of a contaminant film.
Contaminant film on metal surfaces
ToF-SIMS analysis to control the cleaning process
In metal processing, thorough surface cleaning is necessary prior to many process steps. In the event of an insufficient cleaning result, the question arises as to which components are left on the treated surface. If these are very thin, flat or spot-like deposits (contaminant film), a ToF-SIMS analysis in the Tascon laboratory can help identify sources of contamination. In addition, the effect of a reliably functioning cleaning process can be documented by analyses before and after a cleaning step, as the following example from our laboratory shows:
The sections from ToF-SIMS spectra shown in the figure illustrate the chemical changes caused by a cleaning process (surfactant solution & ultrasound) on a stainless steel surface. Mineral oil and fatty acid conjugates are clearly detected on the unwashed surface. On the basis of the spectrum of negatively charged secondary ions, even individual fatty acid conjugates (e.g. palmitate (255 u), arachidate (311u)) can be distinguished. After the cleaning step, the intensities of the characteristic mineral oil and fatty acid conjugate signals are significantly reduced.
Tascon - Your partner for the analysis of filmic contaminants
Are you active in a manufacturing industry where it is crucial to avoid contaminant films? Then you are at the right address at Tascon: Thanks to our many years of experience in the analysis of contaminant films, we can assist you in a targeted and supportive manner. Are you interested in an analysis for contaminant films? Then get in touch with us. We look forward to your inquiry.