TFE Monomer is generally manufactured by synthesis of Calcium Fluoride (Fluorospar), Sulphuric Acid & Chloroform. The polymerisation of TFE is carried out in carefully controlled conditions to form PTFE.
Due to presence of stable & strong C-F bonds, PTFE molecule possesses outstanding chemical inertness, high heat resistance & remarkable electrical insulation characteristics; in addition to excellent frictional properties.
PTFE is high performance engineering specialty polymer invented by Dr. Roy J. Plunkett at Du Pont's Jackson Laboratory, New Jersey, US, on 6th April 1938. As the polymer was found to have exceptional properties with regards to chemical inertness, heat resistance & frictional properties; developmental manufacturing began in 1943 with joint efforts of Kinetic Engineering Inc, USA & E.I. Du Pont de Nemours & Co. Inc., USA. The commercial production went operational by E.I. Du Pont de Nemours & Co. Inc., USA in 1948. The worldwide consumption of PTFE is around 45,000 Tonnes in 1997 & expected to grow at the rate of 10% per annum.
|Property||Unit||Test Method||Virgin PTFE||25% Glass Filled PTFE||25% Carbon Filled PTFE||60% Bronze Filled PTFE|
|Mechanical||1. Density||gm/cc||ASTM D-792||2.1-2.2||2.25||2.14||3.8|
|2. Tensile strength||kgf/cm2||ASTM D-638||210-350||125-200||120-155||105-140|
|3. Elongation of Break||%||ASTM D-638||250-400||200-300||100-150||80-160|
|4. Compressive strength||kgf/cm2||ASTM D-695||40-50||75-85||75-85||115-125|
|5. Compressive modulus||kgf/cm2||4000||7000||8400||8800|
|6. Deformation A. 2 Hrs 23°C, 140kg/cm2 B. 24 Hrs. 23°C, 140kg/cm2 C. Permanent D. 2 Hrs. 150°C, 200kg/cm2||%||ASTM D-621||12 15 8 50||9 11 7 50||4 5 2.5 33||4 5 2.5 40|
|7. Flexural strength||kgf/cm2||ASTM D-790||57||42||96||80|
|8. Flexural Modulus||kgf/cm2||ASTM D-790||3500-6300||16700||11900||13800|
|9. Impact Strength A. -20°C B. +20°C C. Static P-35 kg/cm2||cm kg/cm2||ASTM D-256||9 15||9.5 11||7.5 10||11 10|
|10. Hardness||Scale D||Shore||60-65||70-75||70-75||70-75|