Superwool XTRA low biopersistent fibre for iron and steel

Superwool XTRA, a low-biopersistent fibre, meets stringent environmental requirements in addition to high-temperature tolerance and improved pollutant resistance.

Lining iron and steel furnaces is critical to extend the life of the furnaces and to protect the purity of the metals being heat treated. Therefore, choosing the best material to meet these needs is crucial. For many years, the first-choice material for the industry has been refractory ceramic fibre (RCF), which can withstand the extreme temperatures within the furnace and has strong resistance to pollutants.

However, RCF has environmental, health, and safety (EHS) concerns. After numerous studies, RCF was classified as a category 1b carcinogen in Europe and is considered a substance of very high concern (SVHC) under REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals).

There’s already pressure from European legislators to find safer alternatives, under the Carcinogens Directive, where technically possible, substitutes to RCF should be used. RCF is currently under consideration for further regulation in Europe, which will make the use of RCF more difficult with constraints and stringent controls likely to come into force.

This is compounded by the increasing commitment of major industrial companies and trade associations to improve green standards, placing the onus on the fibre industry to find alternatives that match the performance of RCF without adverse effects.

Backed by almost 10 years of research and development and more than 30 months in trials at customer furnaces, Morgan Advanced Materials’ Thermal Ceramics business has launched Superwool XTRA, a material that delivers the performance of RCF without the inherent EHS risks associated with it.

Since the 1990s, the Superwool brand has been a mark of quality in creating low bio-persistent (LBP) fibres that minimise health risk to furnace installers, operators, and other factory employees. Morgan Advanced Materials has achieved major advances in the performance of LBP fibres through Superwool HT and Superwool Plus grades.

A different fibre
Superwool XTRA delivers the strength that industrial applications need, both in terms of its resistance to high temperatures and pollutants, but also its improved EHS credentials.

With a classification temperature of 1 450 degrees C, Superwool XTRA offers a performance equal, and in many cases superior, to RCF. The fibre is unusual in that it expands when heated to close shrinkage gaps at high temperatures. This is reversible, so when it cools, the shrinkage gaps return and are visible. Once heated again, it expands and closes the gaps again.

This means there is no reason to fill the shrinkage gaps with blanket – the normal practice for RCF. With a two per cent shrinkage, open gaps with RCF normally require an installer to fill these gaps with thin blanket. This is not only time-consuming, but more material is required, adding to costs.

In terms of EHS qualities, Superwool XTRA is exonerated from any carcinogenic classification under nota Q of directive 97/69EC.

A key benefit is Superwool XTRA does not form crystalline silica, a common by-product when many refractories are heated to high temperatures. Having a fibre that produces no crystalline silica is a major breakthrough for the industry, which enhances EHS compliance.

For further details contact Morgan Advanced Materials on TEL: 011 908 0108 or visit