Technical Data Sheet
Carbon Filled Teflon Seal Ring
Paper Industry
Polytetra Processors
Rakhial, Ahmedabad, Gujarat, India
www.automatasia.com
The heart of the rotary joint, manufactured from carbon filled Teflon offering more wear resistance than ordinary carbon seal rings with far less chance of bulging and breakage.
Specification
| Sizes | Custom rotary-joint diameters and sections |
|---|---|
| Tolerances | Machined fit and face finish to approved drawing |
| Grades | 25% Carbon-filled PTFE, Graphite-filled PTFE, Virgin PTFE on request |
| Standards | ASTM D4894, ASTM D4745 |
| Typical uses | Rotary joint sealing, Dryer cylinder service |
| Industries | Paper mills, Pulp & board |
Typical properties — virgin PTFE
| Property | Typical value | Test method |
|---|---|---|
| Specific gravity | 2.14 – 2.20 | ASTM D792 |
| Tensile strength | 20 – 35 MPa | ASTM D638 / D4894 |
| Elongation at break | 200 – 400 % | ASTM D638 / D4894 |
| Hardness | Shore D 50 – 65 | ASTM D2240 |
| Coefficient of friction (dynamic) | 0.04 – 0.10 | ASTM D1894 |
| Continuous service temperature | −200 °C to +260 °C | — |
| Melting point | ≈ 327 °C | ASTM D4894 |
| Dielectric strength | ≈ 32 kV/mm (short time, thin section) | ASTM D149 |
| Water absorption | < 0.01 % | ASTM D570 |
Typical values for guidance only, not guaranteed minimums. Filled grades, linings and finished parts differ; confirm limits for your application. Issued 2026.