We manufacture PTFE and other fluoroplastic parts. We have been requested to make parts that can be bonded to metals. Is there a good adhesive, some sort of additive to the PTFE, or a surface treatment that we can use?
Polytetrafluoroethylene (PTFE) is a high-performance plastic used in a variety of industries, particularly for its heat and chemical resistance and “non-stick” properties. However, PTFE has a low surface energy that does not allow adhesives to wet its surface and subsequently bond.
Some modern acrylic structural adhesives will give moderate adhesive strength. In order to get better adhesion, it is necessary to etch the surface aggressively with chemical agents. The oldest of these is a mixture of sodium metal and ammonia. This significantly improves adhesion, but the surface morphology is changed considerably and chemically damaged by the etching. Furthermore, the surface becomes brown in color, although this is usually not an issue in an adhesive.