Mica plate for commutators is produced from Muscovite or Phlogopite mica paper by bonding with epoxy resin & subsequently heat pressed & grinded. It gives high mechanical strength & accurate thickness
Characteristics
|
Test Method |
Muscovite mica |
Phlogopite mica |
Mica Content (%) |
IEC 371-2 |
90 ~ 93 |
Binder Content (%) |
IEC 371-2 |
7 ~ 10 |
Colour |
|
White |
Brown / Golden |
Thickness (mm) |
IEC 371-2 |
0.4 – 2.0 |
Thickness Tolerance (mm) |
IEC 371-2 |
± 0.02 |
Standard Size (mm) |
IEC 371-2 |
1200 x 1000 , 1000 x 600 |
Density (kg/m3) |
IEC 371-2 |
2.30 ~ 2.50 x 103 |
2.30 ~ 2.50 x 103 |
Bending strength (N/mm2) |
ISO 178 |
≥300 |
≥300 |
Elastic Modulus (N/mm2) |
ISO 178 |
>80 000 |
> 70 000 |
Thermal Stability |
200ºC 69Mpa |
No Epoxy drop, No mica crack |
No Epoxy drop, No mica crack |
240ºC 69Mpa |
Dielectric strength (KV/mm) |
IEC 243 - 23o C |
>20 |
>20 |
Tensile strength (N/mm2) |
ISO 178 |
> 150 |
> 120 |
Compressibility (%) |
Ce-elastic % |
≤2 |
≤2 |
Cp-elastic % |
≤2.5 |
≤2.5 |
Coefficient of expansion (/ºC) |
┴ to the layers |
60 x 10-6 |
10 x 10-6 |
// to the layers |
10 x 10-6 |
10 x 10-6 |
Heat Conductivity (W/mºC) |
- |
0.3 |
Specific Heat |
- |
0.25 |
