Glass Filled PTFE
Glass-filled PTFE is available in various stock shapes—including rods, sheets, and tubes—for custom machining. You can explore sizing, technical data, and pricing directly through us.
Description
Glass-filled PTFE is a composite material made from virgin PTFE and reinforced with 5% to 40% glass fibres. The glass fibre filler significantly improves PTFE’s mechanical limits by increasing compressive strength, stiffness, and wear resistance. It has improved dimensional stability with a lower coefficient of linear thermal expansion and higher deformation under load.
The material is available in rod, tube, and sheet forms. The most typical percentages of glass fibre in PTFE are 5%, 8%, 10%, 15%, 20%, and 25%.
Advantages and Benefits
Below are the reasons to use glass-filled PTFE materials in rods, tubes and sheets.
Reduced Creep & Cold Flow
Virgin PTFE flattens when subjected to sustained pressure. The glass filler functions as a structural stabiliser.
Increased Compressive Strength
Compressive properties can improve by up to 40% compared to unfilled material.
Improved Wear Resistance
The blend extends the lifespan of moving parts by resisting abrasion.
Maintained Chemical & Electrical Resistance
Glass fillers have minimal negative effect on PTFE’s legendary resistance to most chemicals and high-temperature environments.
Applications
Glass-filled PTFE material is suitable for valve seats and gaskets, washers, and O-rings. It is typically used in seal components for dynamic applications.
Physical Properties of Glass-Filled PTFE
| Test Items | Test Methods | Unit | 10% Glass | 15% Glass | 25% Glass |
|---|---|---|---|---|---|
| Density | ASTM D792 | g/cm3 | 2.2 | 2.22 | 2.24 |
| Hardness Shore D | ASTM D2240 | Sh.D | 59 | 60 | 62 |
| Tensile strength | ASTM D638 | mpa | 23 | 22 | 21 |
| Elongation at break 23°C | ASTM D638 | % | 250 | 230 | 210 |
| Coefficient of static friction | ASTM D1894 | - | 0.15 | 0.16 | 0.18 |
| Thermal conductivity 23°C | DIN 52612 | W/K.m | 0.28 | 0.39 | 0.46 |
| Max water absorption | ASTM D570 | % | 0.013 | 0.015 | 0.02 |
