Basalt fiber

Typical properties of basalt fibers
density	2.60 ... 2.80 g / cm ³
Filament diameter	9… 13 µm
tensile strenght	4.84 GPa (kN / mm ² )
Tensile / E module	91… 110 GPa
Elongation at break	<4%
Temperature resistance	−260 ... + 800 ° C
Thermal conductivity	2 W / (m K)
Specific heat capacity	1 kJ / (kg K)

Basalt fibers are thin fibers made from basalt . Their properties are similar to ceramic fibers and belong to the category of man-made fibers .

Basalt fibers are prepared from a liquid basalt melt at about 1400 (+/- 50) ° C prepared. The fiber is greenish-brown in color. The composition of the melt influences the physical properties of the basalt fiber. In contrast to carbon fiber or aramid fiber , basalt fiber is not stretched but, like glass fiber , amorphous . The high strength of basalt fiber compared to compact basalt is therefore based only on the size effect.

Basalt fibers are used as reinforcement fibers in fiber-plastic composites or as heat protection material. The physical properties and thus the areas of application are similar to those of glass fiber. In the form of insulating wool, however, they are thicker than glass fiber and very brittle. When handling the basalt wool, the smallest pieces of fiber break off and can penetrate the skin, where they can stay for several days. However, a clear distinction must be made here between basalt wool and continuous basalt fiber . Continuous basalt fibers are harmless to health and are mainly used in composite applications (lightweight construction in cars and commercial vehicles). With new technologies, however, even the finest fibers with a thickness of less than 10 µm can be produced and processed into fabric .

The Soviet Union was a leader in the manufacture of basalt fibers . Today basalt fibers are mainly produced in Russia, China , USA and Germany.

composition

The exact chemical composition of the basalt fiber depends on the manufacturer. Figures in percent by mass according to Basaltex .

${\ displaystyle \ mathrm {SiO_ {2}}}$ : 52%
${\ displaystyle \ mathrm {Al_ {2} O_ {3}}}$ : 17%
${\ displaystyle \ mathrm {CaO}}$ : 9%
${\ displaystyle \ mathrm {MgO}}$ : 5%
other components: 17%

Web links

Wiktionary: fiber - explanations of meanings, word origins, synonyms, translations

Basalt, fibers and fabrics (PDF; 149 kB), at swiss-composite.ch, accessed on March 3, 2017.

Basalt fiber network on bafanet.com, accessed March 3, 2017.