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Engineered mineral fibres (Note Q)


Reinforcement and dimensional stability

Due to their shape, Lapinus fibres provide reinforcement and dimensional stability to a composite. The superior performance of Lapinus engineered fibres compared with other mineral fibres is a result of their surface treatment, which ensures chemical or physical bonding between the fibres and the matrix material.

Improved thermal resistance and heat stability

The extremely high melting temperature, a result of our unique chemistry, gives Lapinus mineral fibres excellent performance at elevated temperatures, exceeding other fibrous materials such as cellulose, slag, glass and aramid.

Mechanical resistance

As a result of Lapinus fibres’ excellent bonding qualities, the mechanical resistance of the composite increases significantly. This creates increased performance and an extended life span for the end product.

 Fibre characteristics


Fibre index:Up to 99.9%
Fibre diameter (num. av.)Approx. 5.5 micron
Specific surface areaApprox. 0.20 m2/g
Fibre length125-650 micron
ColourGrey/green or off-white
Hardness6 Moh
Melting pointRoxul®1000 > 1000 ºC/CoatForce® > 700 ºC
Ignition lossMax. 0.3%wt
Moisture contentMax. 0.1%wt
Specific density2.75 ± 0.15 g/cm3


Chemical composition of high-alumina low-silica fibres

Lapinus Roxul®1000 chemistry
Rockbrake®, Rockseal®, Rockforce®
typical average values (%)

Lapinus CoatForce® chemistry

typical average values
CaO + MgO
Na2O + K2O
Other oxides

Chemical Abstract Service (CAS) Registry Number
Roxul®1000 fibres: RN287922-11-6
CoatForce® fibres: RN1010466-98-6

To see the Engineered mineral fibre production process click here.