PTFE (TFE) and PVDF both are experiencing long lead times.

PTFE - Polytetrafluoroethylene  product PTFE (TFE) as well as Kynar  manufacturing requires a mineral called Fluorspar that is mined in Mongolia and China. The world requirement for this mineral has grown significantly, along with the supply has tightened. PTFE materials have high temperature resistance, excellent chemical resistance and really low co-efficient of friction (slick) and is used within a great deal of purposes from non-stick fry cookware to ptfe tape for personal use. This specific mineral is actually a crucial raw material in the manufacturing of fluoropolymers, fluorolubricants and quite a few refrigerants.This escalating demand combined with shortage of raw materials is responsible for a dramatic price increase (almost double in the last year), shortages, and we expect both these factors to keep at it in the near future.

PVDF