In-line activation of plastic and metal surfaces in multicomponent injection moulding by means of Openair® Plasma allows integral composite bonding of plastic-plastic or plastic-metal combinations which hitherto had been incompatible or only slightly compatible for adhesion purposes. In the case of mated pairs which in principle are already compatible with one another the power of adhesion may be further increased and high robustness to external influences is also found.
The compact structure of the head of the Openair® Plasma jet allows its adaptation to a six-axis robot so that selective surface treatment of the bonding area can be carried out later with the injection mould open and under a normal atmosphere. The six-axis robot affords great degrees of freedom in movement which can be exploited with flexible moving lines for plasma pretreatment. Integration within the process chain ensures a continuous, robust and reliable sequence of operations offering advantages for novel part designs and opportunities for savings in mould and process tchnology.
Thanks to the use of the plasma technology supplied by the Plasmatreat company it has been possible in the course of our current projects, such as by way of example the special research area SFB 396 "Robust, shortened process chains for flat lightweight parts" (http://www.sfb396.uni-erlangen.de) or the "Plasma" Industry Group (http://www.inlineplasma.de), to bond initially incompatible materials simply and cleanly to one another by means of this integrated production process.
Prof. Dr.-Ing. D. Drummer
Department of Plastics Technology (Lehrstuhl für Kunststofftechnik LKT)
University of Erlangen-Nürnberg