Specific Property Information

Chemical Resistance

Saffil Alumina Fibres Technical Data
Saffil Fibre with its very high alumina content has outstanding chemical stability and resistance to degradation in a variety of demanding conditions including reducing atmospheres, vacuum at high temperatures and metal oxide contaminated furnace atmospheres.

Operating Atmospheres  Max Saffil Operating Temperature (degC)
Air  1600
Vacuum  1500
Hydrogen  1300

Transition Metal Oxides
In general terms transition metal oxides (eg Pb, Cu, Cr) act to reduce the melting point of fibres based on alumina and silica compositions. The rate of this reaction is considerably less for 96% alumina fibres such as Saffil Fibre due to the low levels of silica giving Saffil Alumina fibre longer lifetimes under these conditions than any other alumina containing fibre.

Saffil alumina fibre can be susceptible to attack from hydrofluoric acid, phosphoric acid and hydrochloric acid. However, in furnace applications these forms of attack will typically lead to premature failure of surrounding steelwork and supports before any serious damage occurs to the fibre.

For further information: telephone the Technical Service Department on:
+44 (0)151 422 6700 Fax: +44 (0)151 422 6701

Saffil Alumina Fibres Technical Data
Typical Physical Properties

Melting Point  >2000 deg C
Specific Heat  1 kJ/kg deg C
Tensile Strength  1.5x103 MN/m 2
Young's Modulus  3x105 MN/m 2
Median Diameter  3.0-3.5 microns
Shot Content  negligible
Alumina Content  95-97 %

For refractory applications, SAFFIL fibres' benefits include:

Stability to 1750°C
Resistance to chemical attack
High resilience
Low linear shrinkage
Very low 'shot' content (negligible)
Low thermal conductivity
Low thermal mass
Immunity to thermal shock
Ease of fabrication
High strength & modulus
Uniform fibre diameter

For other applications, such as filtration and catalyst supports, special grades of SAFFIL fibre are available which offer additional valuable features:
Large surface area
High strength and modulus

SAFFIL fibre, 96 - 97% alumina, is available in mat, bulk, blanket and milled bulk fibre forms.
Products made with SAFFIL fibre can be engineered to be stable to 1750°C. SAFFIL fibre-containing products such as veneering modules, boards, vacuum formed shapes and papers are available for a range of temperatures 1100°C to 1750°C.

Saffil Fibre Products Technical Data Sheets
1. Saffil Felt

Saffil Felt is made from high purity polycrystalline Saffil alumina fibres, designed for use in
applications up to 1600°C . Since their development in the early 1970’s Saffil fibres have been used successfully to overcome problems in demanding high temperature insulation and many other speciality applications.

Saffil Felt is lightweight, intumescent and dust-free. It is supplied as a flexible sheet, which is easily cut to shape. The fibres are held in compression by an acrylic polymer binder which burns out completely at temperatures in excess of about 400 °C and an expansion in its thickness occurs.

The highly resilient and flexible Saffil fibres show exceptional recovery after exposure to heat expanding up to 4x the original thickness after removal of the binder.

Furnace lining life can be extended and installation of the lining can be made easier using Saffil Felt’s expansion characteristics.

The use of Saffil Felt as an installation aid or as a means of upgrading a lining specification allows considerable cost savings to be made.

Control of the crystalline microstructure during manufacture and a high classification temperature result in a highly resilient fibre even when exposed to elevated temperatures.

Low shrinkage at high temperature (1600°C) ensures long life in the most demanding applications.

Resistance to Chemical Attack
The high levels of alumina and low levels of silica and trace element levels ensure chemical stability in the
majority of industrial process conditions.

Saffil Felt is widely used as an expansion gap filling in the construction of industrial furnaces, kilns and in the manufacture of high temperature seals and gaskets. It can also be used in the installation of new refractory linings to overcome the effects of shrinkage in fibre linings and to accommodate expansion in dense refractory installations.

Saffil Customer Services

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+44(0) 151 422 6700
+44(0) 151 422 6701