The seals of domestic appliances such as tumble dryers need an extremely reliable adhesive bond to prevent any moisture penetration even after years of use – and this presents something of a challenge. Plasmatreat was commissioned by Miele to find a solution to this problem for their condenser dryers.
The answer lay in using 2-component PUR foam seals and pretreating the plastic material to be sealed with Openair® plasma: In a single operation, the PP surfaces were cleaned to a microfine level and the non-polar PP was activated to increase the surface energy to over 72mJ/m². This created the perfect conditions for long-term stable adhesion of the PUR foam seals to the plastic.
The entire system is computer-controlled and fully automated. The plasma system is equipped with a robot-controlled rotary nozzle for gently treating relatively large surfaces, as well as a static nozzle for intensively treating complex grooved geometries.