Characteristics and Behavior
Description: PTFE is polytetrafluoroethylene and is available in many grades for a wide range of applications. Products are fabricated from PTFE resin using ram extrusion, molding (for granular resin), and paste extrusion and calendaring techniques (for fine-powder resin), dispersion coating (dispersion based resin).
- Fluorotherm manufactures PTFE paste extruded tubing with the following features:
- PTFE tubing does not contain processing aids that intended as part of the final product.
- External fillers for PTFE tubing may consist of materials such as carbon, boron-nitride, bronze, glass etc., to provide specific performance features such as thermal or electrical conductivity, improved abrasion or cut through resistance
- Extremely high lubricity, thus low coefficient of friction compared to other materials
- PTFE is non-stick and non-wetting (hydrophobic), low surface tension with water
- Excellent dielectric and electrical insulation characteristics
- Exceptional chemical inertness
- Upper temperature use limit for PTFE is 500°F (260°C) under non-stress conditions
- Suitable for
cryogenic conditions. PTFE resins remain
strong and tough down to -320°F (-96°C);
the boiling point of liquid nitrogen.
Several sources have reported some ductility
at -450°F
(-268°C). For details on cryogenic behavior and properties, please contact Fluorotherm - Low extractables
- PTFE is FDA approved resin
- PTFE has UL 94 VO rating for flame resistance, does not burn
- Autoclave and ETO sterilizable
- PTFE resin is USP Class VI approved
- PTFE tubing is easily purged and cleaned
- Tubing made of PTFE fine powder resin is clear at wall thicknesses of less than 0.020” (0.5 mm) and translucent with reasonably good visibility at higher wall thicknesses
- The chemical inertness and UV resistant characteristics of PTFE leads to excellent weathering and aging properties even under aggressive conditions
- PTFE is adversely affected by ionizing (electron beam) irradiation; in fact irradiation is used to produce some useful products
PTFE – Poly tetra fluoro ethylene - TYPICAL PROPERTIES
| Property | Value | Units | Method |
| MECHANICAL PROPERTIES | |||
| Tensile Strength, 73°F | 2500-3000 17 to 21 |
lb/sq.in MPa |
D 638 |
| Elongation, 73°F | 300-600 | % | D 638 |
| Flexural Strength, 73°F | No break at flexure | D 790 | |
| Impact Strength, Izod | 320 @ 77 deg C | J/m | D 256 |
| Compressive Stress at 1% deformation | 609 4.2 |
psi MPa |
D 695 |
| Yield Strength At 23 deg C |
1697 11.7 |
psi MPa |
|
| Density (as polymerized) | 2.28 – 2.29 | gm/cu.cm | |
| THERMAL PROPERTIES | |||
| Coefficient of Linear Expansion | 99 x 10-6 | K-1 | |
| Melting Point | 621 327 |
deg F deg C |
|
| Thermal Conductivity | 1.7 2.94 |
Btu/hr-.ft-deg F watt/meter-K |
ASTM C 177 |
| Specific Heat | 0.25 1.047 |
Btu/lb/deg F kJ/Kg/deg K |
|
| Heat Distortion Temperature, 66 lb/sq.in (0.455 MPa) |
132 | D 648 | |
| Service Temperature | -452 to 500 -269 to 260 |
deg F deg C |
|
| Processing Temperature | 662 to 752 350 to 400 |
deg F deg C |
|
| ELECTRICAL PROPERTIES | |||
| Dielectric Strength, short time, 0.080” | |||
| Surface Arc-Resistance | 700 (no carbon track formed) | sec | D 495 |
| Volume Resistivity | 1019 | ohm-cm | D 257 |
| Surface Resistivity, @ 100% RH | 3.6 x 106 | Ohm sq-1 | D 257 |
| Dielectric Constant, 60 to 2 x 109 cps | 2.1 | ε | D150-81 |
| Dielectric Strength | 15.7 to 19.7 | MV m-1 | |
| Dissipation Factor, 60 to 2 x 109 cps (GHz) | <3 x 10-4 | D150-81 | |
| OTHER PROPERTIES | |||
| Refractive Index | 1.376 | nD 25 | D 542 |
| Water Absorption | <0.01 | % increase in weight | D570-81 |
| Flame Rating+ | VE-0 | UL-94 | |
| Limiting Oxygen Index | >95 | % Oxygen | D 2863 |
| Resistance to Weathering | Excellent | * No change in appearance or properties after more than 20 years exposure in Florida, USA | |
| Static coefficient of friction | 0.05-0.08 | D 1894 | |
| Specific Gravity | 2.1-2.3 | D792-66 (1979) | |
+ Numerical rating for flame spread is not intended to reflect hazards presented by this or any other material under actual fire conditions
NOTE: The information, recommendations and opinions contained herein is only a guide and is intended solely for your consideration, inquiry and verification. The suitability of any material under specific conditions of application is not guaranteed in any manner. Fluorotherm Polymers Inc does not assume legal responsibility for the use of data presented here in any form, under any circumstances, any application, test or communication. Nothing contained herein is to be interpreted as a license or authorization to operate under or infringe any patent.