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The unique properties of polytetrafluoroethylene have made it an indispensable material for a broad and growing list of industries and applications.

PTFE with  high molecular weight and strong carbon fluorine bond in the polymer , makes it an extremely slippery, chemically inert polymer . It has the lowest coefficient of friction of any solid and is very thermally stable.

From friction/ lubricity standpoint of fluoropolymers have long been accepted as an ideal non lubricated bearing material for low speed applications at moderate temperatures.

They are maintenance free,offer extremely low coefficient of friction with out lubrication and are immune to degradation by most chemicals.

NEED FOR ADDING FILLERS :
However, unfilled or virgin PTFE is sometimes an inadequate material for many applications :


The disadvantage being

☛ Unsupported fluoropolymer deforms over time under sustained load, a property known as “Cold Flow”

☛ Fluoropolymer bearings are also prone to wear under continued use.

These short comings have limited the wider use of PTFE and other fluoropolymers in higher load and more critical applications


ROLE OF FILLERS :

Fillers in PTFE Compounds primarily serve


☛ To reduce abrasion in dynamic applications involving contact with mating surfaces

☛ To reduce cold flow typically in context with PTFE under pressure

TYPES OF FILLERS :

Fillers are basically classified as

Inorganic Fillers like

Glass Fiber, Carbon ( Powder / Fiber ), Graphite, Bronze, MoS2, Steel, Aluminium Oxide, Calcium Fluoride, Mica  Etc,.

Since compounds with inorganic fillers have higher frictional coefficient than PTFE , the addition of an internal lubricant to reduce friction is often required.

Typical inorganic fillers meeting this requirement are Graphite and MoS2

 

Organic Fillers like

Fillers with high temperature resistance like Polyimide, Polyphenylene sulphide, Polyether ether ketone ( PEEK), Aromatic Polyester, Aramide form part of this category

Because organic fillers lead to lower the increase of frictional coefficient   than an inorganic filler , PTFE Compounds usually do not require any lubricant additives with organic fillers

Fluoropolymer Blends adopts superior process in sourcing its fillers to achieve desired  electrical, mechanical, thermal and tribological properties that help provide improved wear resistance, increased hardness and thermal conductivity, and reduced linear coefficient of thermal expansion and contraction.