TFE is the precursor monomer for making PTFE. So I'm guessing they just didn't bother with the 'P'. FEP and PFA are two other common variants of Teflon. They are melt processable while PTFE is not. All of the variants are typically difficult to bond to. The typical tricks used to make it bond are chemical etching(probably what you are attempting), plasma pre-etching, corona treatments, etc.