PTFE (TFE) and Kynar both are in short supply.

PTFE - Polytetrafluoroethylene  product PTFE (TFE) and also Kynar-PVDF  manufacturing requires a mineral called Fluorspar that is mined in Mongolia and China. The world requirement for this mineral has grown significantly, additionally, the supply has tightened. PTFE materials have high temperature resistance, excellent chemical resistance and very low co-efficient of friction (slick) and is used throughout a bunch of applications from non-stick fry pots and pans to ptfe tape for use at home. This particular mineral is a critical raw materials within the production of fluoropolymers, fluorolubricants and quite a few refrigerants.This increasing amount of demand joined together with general shortage of raw materials is mainly responsible for a dramatic price increase (almost double throughout the last year), shortages, and we expect both these factors to keep at it in the near future.

Foraflon