Surface pretreatment of plastics for adhesive bonding

Many plastics have a poor tendency to bond to other materials because of their inherent inert chemical structure and thus require a pretreatment. Wet chemical methods are expensive because of the disposal of the waste liquids. In this study, the corona treatment (Ional process), the low-pressure plasma process, and the fluorination process were tested and compared with each other. The following plastics were tested: PP (polypropylene), PBT (polybutyleneterephthalate), PBT blends, and a high-temperature thermoplastic, PEEK (polyetheretherketone). In particular, the low-temperature plasma process results in excellent adhesion strength. In addition, we have shown that the stability of freshly plasma-treated surfaces could be maintained for time periods of at least several days.