Polytetrafluoroethylene (Teflon). A slippery thermoplastic often used as a barrel in the extruder to minimize friction with the filament. Found on http://reprap.org/wiki/Glossary
Polytetrafluoroethylene,a form of synthetic used in waterproof garments. Also known as Teflon. Created by DuPont Chemicals. Found on https://www.encyclo.co.uk/local/23307