For sealing applications that push the limits of temperature and chemical exposure, our silica filled PTFE gasket sheet for high temp is a proven performer in flanged joints, heat exchangers, and reactor covers. This material combines the inherent non-stick and corrosion-resistant properties of polytetrafluoroethylene with a precisely controlled silica filler that raises compressive strength, lowers creep, and improves heat transfer compared to unfilled grades. As a dedicated silica filled PTFE sheet manufacturer, we calibrate filler distribution to avoid weak spots that can lead to premature gasket failure. The result is a PTFE gasket sheet with silica filler that resists cold flow under high bolt loads, maintains dimensional stability through thermal cycling, and seals aggressively against acids, caustics, solvents, and steam. When maintenance intervals are long and process uptime is critical, the high temperature PTFE gasket silica filled version delivers reliable sealing from -200°C up to 260°C, making it a versatile choice for chemical processing, power generation, and pharmaceutical production.
The Silica PTFE Sealing Sheet is manufactured from virgin PTFE resin compounded with amorphous silica, which is uniformly dispersed throughout the matrix. This filler increases hardness, reduces elongation under load, and improves thermal conductivity while retaining the chemical inertness of PTFE. The sheet can be cut into custom gasket shapes with standard cutting tools and is available in thicknesses from 0.5 mm to 6.0 mm. Typical applications include strong mineral acids, alkaline media, heat transfer fluids, food-grade processes, and high-purity chemical lines where contamination must be avoided. Because the sheet is free of binders and lubricants, it does not harden or crack with age and has an indefinite shelf life when stored away from direct sunlight.
Key product attributes:
Typical technical parameters:
| Parameter | Value | Test Method |
|---|---|---|
| Density | 2.1 – 2.2 g/cm³ | ASTM D792 |
| Tensile strength (transverse) | ≥ 14 MPa | ASTM F152 |
| Compressibility | 8 – 12% | ASTM F36 |
| Recovery | ≥ 40% | ASTM F36 |
| Hardness | 60 – 65 Shore D | ASTM D2240 |
| Sealing tightness | < 0.1 mg/(s·m) helium | DIN 3535-6 |
| Thickness tolerance | ±0.05 mm for sheets ≤ 1.5 mm | Internal standard |
| Standard sheet sizes | 1500 mm × 1500 mm, 1500 mm × 3000 mm | Custom cutting available |
This filled PTFE grade is particularly recommended for large-diameter flanges and glass-lined equipment where excessive bolt torque can crush softer gaskets. The silica reinforcement gives the sealing sheet a higher modulus, so it holds torque better over time and reduces the need for hot retorquing. It also performs well in vacuum service and in cyclic temperature conditions that would cause standard PTFE to relax and leak.
For optimal sealing performance, flange faces should be clean, dry, and free from scratches or corrosion. The sheet can be used with raised face, flat face, and tongue-and-groove flanges, and it is compatible with most standard gasket cutters. It is also suitable for use in oxygen service after proper cleaning and degreasing. Because it contains no asbestos, solvents, or heavy metals, the material meets many environmental and workplace safety requirements.
