When traditional chemical adhesives fail to sufficiently bond dissimilar types of materials, engineers often turn to plasma treatments to solve complex adhesion problems
Whether bonding metal to plastic, silicon to glass, polymers to other polymers of different durometers, biological content to polymeric microtiter plates or even bonding to polytetrafluoroethylene (PTFE), plasma can be used to promote adhesion. Adhesion promotion can be achieved by increasing the surface free energy through several mechanisms, including precision cleaning, chemically or physically modifying the surface, increasing surface area by roughening, and primer coatings, according to Michael Barden of PVA TePla, a company that designs and manufactures plasma systems.
“It is not a question of whether plasma is effective or not,” says Barden. “Plasma is the king of surface activation and the best technology available. It just depends on the circumstances of the application.”