What is glass fiber?

Composition/characteristics

As the industry becomes increasingly diversified from day to day, such properties as higher strength and higher elasticity as well as lower dielectricity than before are required particularly for special uses, such as electronic materials. In order to meet such needs, Nittobo offers a full array of glass fiber products composed of various elements that have unique functions and features.

  General purposes Special materials
Characteristics E glass T glass NE glass
Density (g/cm³)*1 2.6 2.5 2.3
Tensile strength (GPa)*2 3.2 4.8 3.1
Tensile elasticity modulus (GPa) 75 86 64
Maximum elongation percentage (%) 4.8 6.1 4.8
Thermal expansion coefficient (x 10-6/℃)*1 5.6 2.8 3.3
Softening point (℃)*1 844 >1000 -
Dielectric constant [1GHz]*1 6.8 5.4 4.8
Dielectric dissipation factor [1GHz]*1 0.0035 0.0043 0.0015
Characteristics
  • Electrical insulation
  • High tensile strength
  • High tensile elasticity
  • High heat resistance
  • Low dielectric constant
  • Low dielectric dissipation factor
  • *1 Measured values for lumps of glass
  • *2 Measured using glass fiber called "virgin fiber", which has less defects. Values thus obtained indicate those close to an ideal level of strength.
  • * All data listed above are examples of actually measured values and not standard ones.
  General purposes Special materials
Composition E glass (%) T glass (%)
SiO₂ 52 ~ 56 64 ~ 66
Al₂O₃ 12 ~ 16 24 ~ 26
CaO 20 ~ 25 -
MgO 9 ~ 11
R₂O 0 ~ 0.8 -
B₂O₃ 5 ~ 10 -
ZnO - -

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