What are the benefits of using fillers in PTFE?
February 2018
What are the benefits of using fillers in PTFE?
PTFE is a tough, non-stick, low friction material. Because of its flexibility PTFE can creep and deform under heavy loads but this can be alleviated by adding filler. Fillers can also add other advantages such as improved thermal properties or increased wear resistance but which filler should you use?
Glass
Glass is the most commonly used filler for PTFE, its advantages are it makes PTFE more resistant to creep and wear, it provides increased chemical resistance and makes it more suitable for higher pressure applications.
The disadvantage is that it will make the PTFE much more abrasive on mating surfaces.
Carbon
Carbon improves compressive strength making the PTFE more resistant to wear and reducing deformation. Carbon is also conductive so it is suitable to applications that require higher thermal conductivity.
Carbon is less abrasive than Glass.
Graphite
Graphite provides a self-lubricating property to PTFE; it is usually combined with other fillers such as Glass or Carbon.
Graphite reduces the coefficient of friction of PTFE.
Bronze
Bronze makes PTFE more resistant to wear and creep, it also improves thermal and electrical conductivity.
The disadvantages are reduced chemical resistance and non-stick properties.
Stainless Steel
Stainless steel increases resistance to wear and load, Stainless Steel filled PTFE works well in applications that are subject to steam or hot liquids.
May cause wear to mating surfaces.
MoS2 (Moly)
Moly is used to increase anti-friction properties as it has a lubricating effect. Moly is often used with Glass or Bronze
