The ever increasing requirements on the efficiency of production processes, on the protection of resources, and on lightweight energy-saving design are all creating challenges to the automotive industry which cannot be met with the traditional sheet metal design any longer. In order to reduce the total weight of the vehicles, many components must be manufactured in modern lightweight design. The subject of research of the joint project EFFICOAT which is funded by the German Federal Ministry of Education and Research and supported by the project promoter Karlsruhe, is the production of hybrid monocoque components with paintable Class A surfaces of thermoplastic composite structure while saving up to 50% of the resources at the same time.
Current project partners of the joint project EFFICOAT are: The Peguform GmbH, the Anchor Lamina GmbH, the GWK Gesellschaft Wärme Kältetechnik mbH, the KraussMaffei Technologies GmbH, the Plasmatreat GmbH, the Technical University of Chemnitz (Institute for General Mechanical Engineering and Plastics Technology) and the Volkswagen AG.
Plasmatreat has taken on the task to develop adhesion-promoting coatings for the pretreatment and in-situ embedding of sheet metal inlays such as antennas or sensors. For this purpose the most diverse precursors are applied to the surfaces of different metals by means of plasma polymerization with the aid of the PlasmaPlus® process, and the adhesive strengths are determined by tensile-shear testing after the plastic material is molded.
The initial results already indicate some substrate fracture and thereby impressively demonstrate the high adhesive strength of the PlasmaPlus®-treated components and the great potential of plasma coating at atmospheric pressure. Complete substitution of solvent-based primer systems becomes possible through inline application of a dry-chemical primer coating with the aid of the PlasmaPlus® process. The results from EFFICOAT can be transferred in full to other components and utilized by companies of the automotive industry and other industrial segments.
Within the framework of the joint project Protect-Select funded by the German Federal Ministry of Education and Research, the companies Siemens, Epcos and Infineon, the Fraunhofer Institute for Manufacturing Technology and Advanced Materials, and Plasmatreat as a plant manufacturer have got together. The objective was to give electronic components a thin and long-time stable, selective anti-corrosion coating as a protection against corrosive influences and extreme climatic conditions, and all this in an economical and resource-efficient manner. The deposition of these coatings was accomplished by means of the PlasmaPlus® process providing for plasma polymerization at atmospheric pressure.
The Starting Point
Affording electronic units and components selective protection against climatic effects is of utmost importance to the reliability of a wide variety of products. Almost half of all defects on modern passenger cars are attributable to climatically induced aging and corrosion damage to electronic components. Protection against humidity, chemicals and harmful gases - even under extreme temperatures - is an essential prerequisite for avoiding such system failures.
These requirements are presently mainly fulfilled by coatings from paint systems, polymer embedding compounds or gels (silicones). Their use, however, is reaching its limits in terms of economy and ecology given that their application is laborious and time-intensive. The usually solvent-based systems (VOC) can only be applied with comparatively thick coating thicknesses and little selectivity. Depending on the type of protective coating, additional disadvantages may occur such as poor heat dissipation, absorption of moisture, delamination of the applied overcoat or undesired attenuation of the sensors.
The joint project Protect-Select succeeded in the development of a new coating process for electronic components using the Openair-Plasma® technology. By employing the PlasmaPlus® process it is possible to effectively deposit thin, transparent and insulating plasma-polymer anti-aging coatings and to selectively protect electronic units and especially printed circuit boards. Thanks to the high barrier effect of the thin coatings, not only a longer lifetime and product safety can be achieved but also a significant cost reduction.
The project was funded by the German Federal Ministry of Education and Research under the announcement »Smartplas« and »Mikroplas« and the project reference number 13N9244 to 13N9248 and supported by the project promotor VDI Technologiezentrum in Düsseldorf.