Polyvinylidene fluoride and PVDF rods Polyvinylidene fluoride and PVDF rods Polyvinylidene fluoride and PVDF rods
Polyvinylidene fluoride, or PVDF, is hailed as one of the most chemically resistant thermoplastics worldwide, capable of enduring temperatures ranging from -30°C to +150°C. Its exceptional dimensional stability and commendable tribological attributes make PVDF stand out. This flame-retardant, self-extinguishing plastic boasts high density and remarkable strength, even though it exhibits relatively low impact strength at low temperatures.
In a direct comparison with PTFE, PVDF rods exhibit greater durability, despite a higher coefficient of friction. What sets PVDF apart from other fluoropolymers is its unique blend of mechanical, thermal, and electrical properties when subjected to chemical environments.
Like other fluoropolymers, PVDF exhibits minimal moisture absorption and exceptional resistance to hydrolysis. Furthermore, PVDF rods can be welded using specialized welding rods, a feature not shared by PTFE.
Key Advantages of PVDF Rods:
- Lightweight
- Low thermal conductivity
- Exceptional resistance to chemical corrosion
- High heat resistance
- Impressive mechanical strength and toughness
- High abrasion resistance
- Resilience against most chemicals and solvents
- Low permeability to gases and liquids
- Thrives under harsh thermal and chemical conditions
- Unaffected by prolonged exposure to ultraviolet radiation
Applications of PVDF Rods:
Thanks to its excellent weldability, PVDF-coated fiberglass or polyester fabric stands out as the top choice for crafting chemically resistant protective linings in tanks, pumping equipment, and valves utilized in water treatment and TPP stations. It’s especially suitable for handling media containing abrasive or corrosive particles.
PVDF is indispensable in various applications, including:
- Sealing components (such as sealing rings and bushings) – not limited to the chemical industry.
- Electrical components (insulators, contact rails, plugs, connectors, and more).
- Anti-friction and chemically resistant structural elements (sliding bushings, gears, rollers, screws, etc.).
Moreover, PVDF finds extensive use in chemical engineering, where it serves as the go-to material for pump bodies, valve components, flow meters, fittings, and various other vital components used with chemical products and petroleum.
Mechanical Properties
| MECHANICAL PROPERTIES | VALUE | UNIT | PARAMETER | NORM |
|---|---|---|---|---|
| Tensile strength | 62 | MPa | 50mm/min | DIN EN ISO 527-2 |
| Tensile strength at yield | 62 | MPa | 50mm/min | DIN EN ISO 527-2 |
| Elongation at yield | 8 | % | 50mm/min | DIN EN ISO 527-2 |
| Elongation at break | 17 | % | 50mm/min | DIN EN ISO 527-2 |
| Flexural strength | 77 | MPa | 2mm/min, 10 N | DIN EN ISO 178 |
| Modulus of elasticity (flexural test) |
2100 | MPa | 2mm/min, 10 N | DIN EN ISO 178 |
| Compression strength | 16/28/59 | MPa | 1% / 2% / 5% | EN ISO 604 |
| Compression modulus | 1900 | MPa | 5mm/min, 10 N | EN ISO 604 |
| Impact strength (Charpy) | 150 | kJ/m2 | max. 7,5J | DIN EN ISO 179-1eU |
| Ball indentation hardness | 129 | MPa | ISO 2039-1 | |
| Modulus of elasticity (tensile test) |
2200 | MPa | 1mm/min | DIN EN ISO 527-2 |
Thermal Properties
| THERMAL PROPERTIES | VALUE | UNIT | PARAMETER | NORM |
|---|---|---|---|---|
| Glass transition temperature | -40 | C | DIN EN ISO 11357 | |
| Melting temperature | 171 | C | DIN EN ISO 11357 | |
| Service temperature | 150 | C | short term | NN |
| Service temperature | 150 | C | long term | NN |
| Thermal expansion (CLTE) | 16 | 10-5*1/K | 23-60°C, long. | DIN EN ISO 11359-1;2 |
| Thermal expansion (CLTE) | 18 | 10-5*1/K | 23-100°C, long. | DIN EN ISO 11359-1;2 |
| Thermal conductivity | 0.25 | W/(k*m) | ISO 22007-4:2008 | |
| Specific heat | 1.3 | J/(g*K) | ISO 22007-4:2008 |
Electrical Properties
| ELECTRICAL PROPERTIES | VALUE | UNIT | PARAMETER | NORM |
|---|---|---|---|---|
| surface resistivity | 1014 | O | DIN IEC 60093 |
Other Properties
| OTHER PROPERTIES | VALUE | UNIT | PARAMETER | NORM |
|---|---|---|---|---|
| Flammability (UL94) | V0 | – | corresponding to | DIN IEC 60695-11-10; |
| Resistance to hot water/ bases | + | – | – | |
| Resistance to weathering | + | – | NN | |
| Water absorption | <0.01 | % | 24h / 96h (23°C) | DIN EN ISO 62 |
