What is PTFE?
PTFE (Polytetrafluorethylen) hat eine molekulare Struktur basierend auf einer Kette von Kohlenstoffatomen. Im Gegensatz zu einigen anderen Fluorkunststoffen ist jedes PTFE Kohlenstoffatom mit zwei Fluoratomen verknüpft, die spiralförmig die Kohlenstoffkette umgibt und so vor den Einwirkungen durch Chemikalien schützt.
Diese Kohlenstoff-Fluorverbindung ist eine der stärksten Bindungen in der Polymerchemie. Es ist diese Bindung, die PTFE zu seinen einzigartigen Eigenschaften und unvergleichlichen chemischen Beständigkeit verhilft.
Key properties
PTFE ist FDA konform 21 CFR 177.1550 bzw. FDA 21 CFR 178.3297 (antistatisches PTFE)
The table below lists a generally accepted summary of properties that we believe to be reliable. Please note that many of these resins are produced in several varieties and property characteristics may vary. Therefore, determination of resin is dependent on the application and this table is only meant to serve as a general guideline.
Properties | ASTM or unit | PTFE |
MECHANICAL PROPERTIES | ||
Specific Gravity | D792 | 2.18 |
Elongation % | D638 | 200 ~ 450 |
Tensile Strength (psi) | D638 | 2,000~7,000 |
Flexural Strength (psi) | D790 | no break |
Compressive Strength | D695 | 3.500 |
Tensile Elastic Modulus (Young’s Modulus) (psi) | D638 | 57.000 |
(psi) Flexural Modulus 103MPa (103kgf/cm2) | D790 D790 |
71,000 ~ 85,000 0.5-0.6 (5.0-6.0) |
FlexLife (MIT cycles) | D2176 | >1,000,000 |
Hardness Durometer Shore D | D636 | D50 ~ 65 |
Coefficient of Friction | On steel | 0.02 |
Abrasion Resistance 1000 revs. | Taber | 12 |
Impact Strength IZOD 73°F/23°C, notched ft/lbs/in | D256 | 3 |
Properties | ASTM or unit | PTFE |
THERMAL PROPERTIES | ||
Melting Point | °C (°F) | 327 (621) |
Upper Service Temperature(20,000h) | °C (°F) | 260 (500) |
Flame Rating** | UL 94 | V-0 |
Thermal Conductivity | BTU/hr/ft2/deg F in cal/sec/cm2,ºC/cm |
1.7 6 x 10-4 |
Linear Coefficient of Thermal Expansion 10-5 °C | D696 | >11.6 |
Heat of Fusion | BTU/LB | 29-37 |
Heat of Combustion | BTU/LB | 2200 |
Low Temperature Embrittlement | °C (°F) | -268 (-450) |
Properties | ASTM or unit | PTFE |
ELECTRICAL PROPERTIES | ||
Dielectric Constant | D150/103Hz D150/106Hz |
2.1 2.1 |
Dielectric Strength 10 mil film | D149 | >1400 |
Volume Resistivity ohm-cm | D257 | >1018 |
Surface Resistivity ohm/sq. | D257 | >1017 |
Properties | ASTM or unit | PTFE |
GENERAL PROPERTIES | ||
Chemical/Solvent Resistance | D543 | Excellent |
Water Absorption, 24h | % | >0.01 |
Deformation Under Load | *D621/100°C **D621/25°C |
5.0 7.0 |
Refractive Index | 1.35 | |
Limiting Oxygen Index | >95 | >95 |
Properties | ASTM or Unit | PTFE |
*6.8 MPa (986 psi),24h **13.7 MPa (1987 psi),24h |