
Compressed fibre materials are based upon production techniques initially used for compressed asbestos fibres, the so called IT techniques (gumI asbesT). After the banning of asbestos, there has been no direct equivalent due to its unique chemical properties. Compressed fibre materials can be an alternative to the solution, but the range of use is much smaller than that of the asbestos and is much more dependent on the fibre mixture used during manufacturing.
Asbestos-free sealing plates are bonded during manufacturing by using elastomers. This provides more safety when cutting, and flexibility for handling and assemblage. During its usage, especially with temperatures above 100°C, the elastomer will bind. Even though this does not necessarily affect the integrity of the gasket at its place, it can affect its ability to offer a reliable performance regarding temperature and pressure. Usually, good quality gaskets contain a small quantity of binder. Nowadays, aramide, carbon, glass fibres are being used in order to replace the asbestos ones, and for the growth of density – mineral fibres.
Standard size 1500 mm x 1500 mm; 1500 mm x 3000 mm.
Standard thickness: 0,5 mm; 0,8 mm; 1 mm; 1,5 mm; 2 mm; 2,5 mm; 3 mm; 4 mm; 5 mm; 6 mm.
Upon client request, the plates can be reinforced or graphited on both sides (AF 302 – ZS, AF 302 – 2G, respectively AF 302 – ZS – 2G).
Main types of asbestos-free sealing sheets:
Name | AF-302 | AF 302 ZS | AF-200 UNIVERSAL | AF-200 Universal ZS | AF-Oil | AF-Oil ZS | Grafex Carb |
Composition | Mineral fibres + Natural fibres+ NBR | Mineral fibres + Aramid fibres + NBR | Aramid fibres + Mineral fibres + NBR | Carbon fibres + NBR | |||
Sheet type | No insertion | Wire mesh insertion | No insertion | Wire mesh insertion | No insertion | Wire mesh insertion | No Insertion |
Pmax (bar) | 30 | 40 | 60 | 80 | 100 | 120 | 100 |
Tmax (°C) | 180 | 230 | 300 | 350 | 350 | 380 | 450 |
Tmax continuous (°C) | 150 | 200 | 220 | 270 | 300 | 350 | 250 |
Tmax steam (°C) | 130 | 130 | 180 | 180 | 230 | 230 | 200 |
Working fluids | Water, steam, oil, solvents, etc | Water, steam, oil, solvents, etc | Water, steam, oil, solvents, weak acid or base solutions etc | Water, steam, oil, solvents, weak acid or base solutions, etc | Water, steam, oil, solvents, weak acid or base solutions, etc | Water, steam, oil, solvents, weak acid or base solution, etc | Water, steam, oil, solvents, acid or base solution, etc |