Cap Ptfe Liner found in: PTFE Cap Liners, 9mm R.A.M. Caps with PTFE Liner, Cap, Phenolic, PTFE Liner, 38-430, Corning® Reusable Phenolic GPI 24-400.. PTFE-lined caps used on our aijiren Tech glass environmental sample containers. The PTFE liner is bonded to the cap so it won't fall out or become separated from the cap.