The technologies of sealing and adhesive bonding are closely related to surface engineering. Surfaces must be well prepared in order to obtain perdurable bonding results. Cleaning with solvents, grinding or pre-coating are traditional methods for the pre-treatment of a base surface. These methods share common disadvantages, however, including high costs, insufficient automation feasibility and, in some cases, a detrimental effect on the environment.
The use of atmospheric pressure plasma is an environmentally friendly, cost-efficient and high-tech alternative to traditional pretreatment methods. It allows for ultrafine cleaning and strong activation of material surfaces for lasting, stable adhesion of adhesives and coatings.
THE FOURTH STATE OF MATTER
Plasma is based on a simple physical principle. A supply of energy can change the states of matter from solid to liquid and from liquid to gaseous. If further energy is added to a gas, it becomes ionized (i.e., the electrons gain more kinetic energy and leave their atomic shells). Free electrons, ions and molecular fragments are formed, and the gas turns into a plasma state, which is also known as the fourth state of matter. Previously, however, this state could hardly be used in industrial production at normal pressure because of its instability.
In 1995, the invention of the patented Openair atmospheric pressure plasma-jet technology from Plasmatreat (Germany) opened up new possibilities. By developing and using plasma nozzles, it became possible to integrate a rarely used state of matter for industrial production processes and consequently make plasma usable for large-scale, in-line pretreatment of material surfaces in a normal atmosphere.