Laser and plasma pre-treatment
Surface pre-treatment:
The purpose of
the surface pre-treatment is to remove disturbing films and to
build up films, which prevent corrosion and have
adhesion-providing qualities. Thus we achieve a good wetting
and a high bond strength by an intensive interaction between
the joint surface and the adhesive.
Laser pre-treatment:
By processing the joint surface with short-pulsed laser
radiation we remove organic and inorganic films, without
thermally stressing the joint. Here we mainly apply pulsed
solid-state lasers ( e.g.Nd:YAG) but also fiber lasers . In
dependence of the material, to be removed, we apply
wave-length ranging from the mean IR to the EV range. We
investigate further influences on the surface caused by
laser radiation.
Plasma pre-treatment:
Thin organic films are deposited by atmospheric plasma.
Nonpolar polymer surfaces, which hardly interact with the
adhesive, thus can be functionalized and be bonded.
Furthermore, at the IWS it is possible to deposit films,
suitable for the adhesive process, by atmospheric plasma
(PA-CVD).