TFE-M - Chemically Modified PTFE Shapes :
To over come some of the weaknesses of conventional PTFE , scientists has developed the new chemically modified PTFE available as Dupont's Teflon Nxt or Dalkin's TFM and have improved some of the properties for the benefit of consumers
Improvements At a Glance :
Improved Creep Resistance :
As PTFE Gasketing & Sealing materials used in chemical process industries, due to improved creep resistance & increased stiffness even at elevated temperatures. The modified PTFE components can be used for higher pressure conditions.
Enhanced Permeation Resistance
:
The vessal linings, Tubings, Sealing materials, Expansion joints, Made out of modified PTFE have more life & less / near zero leakage due this enhanced permeation resistance.
Superior Surface Finish :
The Components, surfaces made out of modified PTFE have superior surface finish with silky / glossy surfaces. The components remain absolutely clean as there is virtually no place for impurities to get a grip.
Reduced Porousity :
The parts made out of modified PTFE have low microvoid content, thus showing the transmigration of aggressive liquids & gases through.
Better High Voltage Insulation :
Modified PTFE allows better high voltage insulation giving new opportunities to improve performance particularly in electrical applications.
Weldability :
The threaded joints / snug fit joints can be avoided by using directly welded part to part, thus reducing the risk of leakage through threaded joints.
Typical Properties of Modified PTFE V/V Conventional PTFE :
| PROPERTY |
TEST METHOD |
UNIT |
Teflon
NXT |
PTFE |
| Tensile Strength |
ASTM-D-4894 |
MPa (psi) |
31 (4,500) |
34 (5,000) |
| Elongation at Break |
ASTM-D-4894 |
% |
450 |
375 |
| Specific Gravity |
ASTM-D-4894 |
|
2.17 |
2.16 |
Deformation Under Load (Creep),
23oC (73oF) |
ASTM-D-695 |
% |
100 |
|
| 3.4 MPa (500 psi) |
|
|
0.2 |
0.7 |
| 6.9 MPa (1,000 psi) |
|
|
0.4 |
1.0 |
| 14 MPa (2,000 psi) |
|
|
3.2 |
8.2 |
| Deformation Under Load (Creep), - DMA |
|
|
|
|
| 6.9 MPa (1,000 psi) at 25oC (77oF) |
|
|
5.3 |
6.7 |
| 3.4 MPa (500 psi) at 100oC (212oF) |
|
|
5.4 |
8.5 |
| 1.4 MPa (200 psi) at 200oC (392oF) |
|
|
3.6 |
6.4 |
| Void Content of Typical Parts |
FTIR - Infrared
spectroscopy |
% |
Compression
Moulded: 0-0.5 |
Compression
Moulded: 0-1.5 |
Dielectric Strength, 76.2um
(0.003 in) Film |
ASTM-D-149 |
kV/mm
(V/0.001 in) |
32 |
24 |
| Weld Strength ( Specimens welded after Sintering) |
ASTM-D-4894 |
% |
66-87 |
|
Comparative Permeation Rates For Modified PTFE & Conventional PTFE :
| Permeant |
Specimen Thickness,
mm (in)
| Vapor |
Liquid |
Gas |
| PTFE |
TFE-M |
PTFE |
TFE-M |
PTFE |
TFE-M |
| Perchloroethylene |
1 (0.04) |
5.5 |
2 |
13 |
4 |
- |
- |
| Perchloroethylene |
2 (0.08) |
1.4 |
0.1 |
0.019 |
0.005 |
- |
- |
| Perchloroethylene |
3 (0.16) |
0.08 |
0.05 |
0.006 |
0 |
- |
- |
| Perchloroethylene |
4 (0.20) |
0.055 |
0.050 |
- |
- |
- |
- |
| Hexane |
5 (0.08) |
3.4 |
0.2 |
23.4 |
0 |
- |
- |
Hexane |
6 (0.20) |
0.045 |
0.015 |
- |
- |
- |
- |
| MEK |
7 (0.08) |
36.3 |
23.3 |
49.4 |
34.2 |
- |
- |
| MEK |
8 (0.20) |
22.6 |
20.8 |
35.5 |
25.2 |
- |
- |
HCI, 20% |
9 (0.04) |
0.4 |
0.1 |
- |
- |
- |
- |
Helium |
10 (0.08) |
- |
- |
- |
- |
93 |
1 |
Helium |
11 (0.20) |
- |
- |
- |
- |
0.18 |
0.12 |
Applications :
Due to superior properties of TFE-M to conventional PTFE, the typical application of TFE-M includes Pumps Diaphragms (Improved permeation), Ball Valve Seats (Improved Creep Resistance), Components of Mechanical Seals (Improved permeation and surface finish), Dipped Pipes for reaction vessels (Improved surface finish and weldability), Vessel Lining (Improved permeation and weldability)
Product Range :
All the products mentioned in 'FLUSTOX' can be made available in TFE-M
 |
