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.
Acids
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) |
| • | Lightweight |
| • | 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 Introduction
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.
Description
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.
Benefits Expansion
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.
Resilience
Control of the crystalline microstructure
during manufacture and a high classification temperature result in a highly
resilient fibre even when exposed to elevated
temperatures.
Refractoriness
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.
Applications
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.