Practically any material that can withstand the sintering temperature of PTFE can be used as filler. Characteristics such as particle shape and size, and the chemical composition of the filler greatly affect the properties of the compound. All fillers used in PTFE compounds have been carefully selected and were in several cases specially developed to give the best balance of properties. The following paragraphs discuss the main features of the most commonly used fillers.

Category:

FEATURES

PTFE is available in virgin & filled compounds to improve the basic characteristics to match very diverse applications & optimization for specific end users.

Sr.No. Grade Filler Content by weight % Standard series Properties Applications
1 Virgin PTFE Yes Hygienic
Excellent chemical resistance

  • Outstanding electrical properties
  • Excellent flexural properties

 

Gaskets, bellows, food / contact &medicine / human consumption
applications.
2. Glass filled PTFE 15 – 25  Yes
  • High compressive strength
  • Excellent chemical resistance
  • Improved wear resistance under load & permanent deformation

 

Ball valve component, bridge bearing pads, ship launching pads, pipe supporting pads.
3. Carbon/Coke filled PTFE(soft amorphous/ hard fiber) 25 – 35 Yes
  • High compressive strength
  • Improved wear resistance under load & permanent deformation
  • Better thermal / electrical conductivity.

 

Rider and piston rings of air compressor
4. Graphite filled PTFE(pure crystalline carbon) 15 Yes
  • High compressive strength
  • Improved wear resistance under load & permanent deformation
  • Better thermal / electrical conductivity.
  • Good chemical resistance
  • Improved frictional properties.

 

Used as shaft bearings and in chemical high speed Chemical pumps.
5. Bronze filled PTFE(oxidising / Non oxidising) 40 – 60 Yes
  • High compressive strength
  • Excellent wear resistance improved under load & permanent deformation
  • Better thermal / electrical conductivity.
  • Good chemical resistance
  • Very low cold flow.

 

Wear  strips Machine tool liners, hydraulic seals.
6. Bronze plus, Molybdenum Disulphide filled PTFE 55 + 5 Yes
  • Improved fictional properties
  • High compressive strength
  • Excellent wear resistance improved under load & permanent deformation
  • Good thermal / electrical conductivity.
  • Very low cold flow.

 

Hydraulic Seals
7. Aluminium Oxide filled PTFE 5- 10 No
  • Excellent electrical properties
  • Excellent  compressive strength
  • Excellent wear resistance improved under load & permanent deformation

 

Electrical insulators in circuit breaker
8. Calcium Fluoride filled PTFE 5-10 No
  • Excellent chemical resistance
  • Improved wear resistance under load & permanent deformation
  • Excellent  compressive strength
  • Good with chemicals that attack glass

 

Mechanical Seal parts .
9. Stainless Steel filled PTFE 5- 10 No
  • Excellent chemical resistance
  • Outstanding mechanical properties
  • Good wear resistance

 

High Pressure chemical handling equipments
10. Mica filled PTFE 5-10 No
  • Very low coefficient of thermal expansion
  • Excellent compressive strength
  • Poor tensile properties

 

11. Glass + MoS2 filled PTFE 15 + 5 Yes
  • High compressive strength
  • Excellent chemical resistance
  • Improved wear resistance under load & permanent deformation
  • Improved frictional properties

 

Low torque valve components
12. Pigmented PTFE No Improved  visibility Colour  coded electrical  cable sheathings