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

PTFE - Polytetrafluoroethylene  product PTFE (TFE) and Kynar  manufacturing requires a mineral called Fluorspar which is mined in Mongolia and China. The worldwide demand for this mineral has risen significantly, along with the supply has tightened. PTFE materials have high temperature resistance, excellent chemical resistance and very low co-efficient of friction (slippery) and is utilized within tons of applications from non-stick fry griddles to ptfe tape for personal use. This particular mineral is actually a crucial raw material inside the manufacturing of fluoropolymers, fluorolubricants and lots of refrigerants.This rise in demand coupled with shortage of raw materials is responsible for a dramatic price increase (almost double over the last year), shortages, and we expect both these factors to continue in the near future.

Foraflon