Vejledning 3 - Isoleringssystemer / Mineraluld
Mineral Wool
Insulation made of man-made materials
The basic raw material for mineral wool is sand and basalt rocks. These resources are abundant and usually locally found. In the case only sand is used, the final product will be glass wool (fibre glass), in the case only slag and basalt are used, final product will be stone wool (rock wool). For glass wool the recycled glass and fluxing agents are usually added. Glass wool and stone wool together are covered under the name mineral wool.
During the production process, the raw materials are melted in a furnace where the temperature reaches 1300-1500 °C. The obtained liquid materials are going to fiberizing process. This process takes place in a device where disks with small holes and centrifugal force or rotating nozzles are used to create fibres. Binding products and additives (usually dust abatement oil and phenolic resin) are used to form the final product.
Typical final products are distributed as mats and boards or sometimes as filling material. The mineral wool can be used to fill in frames, cavities, floors and roofs. The perforation and cutting can be done at the construction site without losing the thermal properties of the material.
Thermal properties of mineral wool are dependent on temperature, moisture content and mass density of the material itself. Typical values for the thermal conductivity of mineral wool is 0.03 – 0.04 W/(mK), while the reference standard EN 13162:2012 gives values of 0.034 – 0.045 W/(m K) for dry material at 10 °C. The thermal conductivity increases 30 % (from 0.037 W/(m K) to 0.055 W/(m K)) in the case the moisture content in the insulation material increases from 0 vol% to 10 vol%.