Fluoropolymers are a group of polymers in which all, or most, of the hydrogen has been replaced with fluorine. They have a wide range of mechanical, frictional, chemical, and electrical properties which make them ideal for a many different applications. However, these properties result in such low surface energy levels they are difficult to bond without surface pretreatment.
Sodium-etch solutions are one common surface treatment used for bonding, but they have significant disadvantages. The wet chemicals are expensive and dangerous, do not coat uniformly, and are very difficult to dispose of. A better method of preparing polymers for bonding is by plasma treatment.
The TriStar team has had good results with surface treatment of fluoropolymers such as FEP,PFA, Tefzel®, and PTFE (Teflon®) with gas plasma. If an appropriate process is used, the surface of the fluoropolymer is chemically modified and becomes water-wettable, printable and bondable with structural adhesives. The plasma treatment is uniform, dry (no wet chemistries), efficient, and safe. And the process is earth-friendly with no disposal issues.