Karl Trautz¹, Markus Mitschele², Alexander Götz³, Richard Starkey⁴, Daniel Schäfer^3
1HEMO GmbH, Bretten, Germany
²FIT Fachverband Industrielle Teilereinigung, Neuffen, Germany
³HEMO GmbH, Ötisheim, Germany
⁴Safechem Europe GmbH, Düsseldorf, Germany
High-tech coating processes require much higher component cleanliness levels compared to conventional coating processes. Considering the wide range of contaminants that need to be removed, it is a major challenge to find the optimum cleaning process in terms of the cost-benefit ratio.
Here it is interesting to consider the previously underrepresented use of modern organic solvents, if necessary, in combination with aqueous cleaning media.
In this context, the important principle of cleaning technology must be taken into account: "like dissolves like".
This principle means that non-organic (polar, hydrophilic) contaminants should preferably be cleaned with aqueous media and organic (non-polar, lipophilic) contaminants should preferably be cleaned with organic solvents such as modified alcohols or isoparaffins.
Tried and tested processes are provided by manufacturers of cleaning systems in combination with organic solvents and aqueous detergents from manufacturers and suppliers of solvents and detergents.
Manufacturers and suppliers of solvents provide various solvents that are already well known in degreasing of parts. They are approved solvents in many industries, such as the aviation and automotive industries. These organic solvents are isoparaffins (hydrocarbons with chain lengths C9 to C14) or modified alcohols.
Manufacturers and suppliers of aqueous detergents provide various detergents that are already known in parts cleaning, but also newly formulated cleaners, preferably salt-free, but in some cases also containing salt. They are also approved in many industries, such as the aircraft and automotive industries.
Manufacturers of cleaning systems provide the process engineering systems. Depending on requirements, these are either pure solvent applications or, if necessary, hybrid technologies such as Beyond or Hybrid.
In the hybrid process, organic solvents and aqueous media with detergents are used one after the other, but in the same working chamber. In the Beyond process, organic solvents are used in a mixture with demineralized water.