Basalt fiber

Basalt fibers are thin fibers of basalt and belong to the category of chemical fibers.

They are made of a liquid basalt melt at about 1400 ° C. The fiber has a greenish-brown color. The composition of the melt, affect the physical properties of the basalt fiber. In contrast to the carbon fiber or aramid fiber, the basalt fiber is not stretched, but, as the fiber is amorphous. The high strength of the basalt fiber, in comparison to the compact basalt, therefore depends only on the size effect.

Basalt fibers are used as reinforcing fibers in fiber - reinforced polymer composites or used as thermal protection. The physical properties and thus the areas of application are similar to those of glass fiber. However, in the form of insulating wool they thicker than fiberglass and very brittle. In dealing with the basalt wool fiber smallest pieces break off and can penetrate the skin, where they can keep for several days. However, one must clearly distinguish between basalt wool and continuous basalt fiber here. Continuous basalt fibers are not harmful to health and find their use mostly in composite applications (lightweight for cars and trucks). With new technologies but can also be made very fine fibers having a thickness of less than 10 microns, and processed to the tissue.

In the production of basalt fibers, the Soviet Union was a leader. Today, basalt fibers are mainly manufactured in Russia, China, USA and Germany.


The exact chemical composition of the basalt fiber depends on the manufacturer. Information in mass percent, according to company Basaltex.

  • 52%
  • : 17%
  • : 9%
  • : 5%
  • Other ingredients: 17%
  • Man-made fiber
  • Reinforcing fiber
  • Dämmfaser

Pictures of Basalt fiber