SCHOTT B 270® Crown White (Superwhite)
SCHOTT offers B 270® crown glass in sheet glass form to meet a wide variety of different market demands, especially suitable for Biotech applications. It is manufactured using a special up-draw process developed by SCHOTT.
B 270® i is highly resistant to solar radiation and offers high transmittance in the visible wavelength range. It also has a fire-polished surface and offers high chemical stability.
Features
- High transmission
- Excellent surface quality
- Can be thermally or chemically strengthened
Applications
- Large area LCD covers
- Cover panes for copying machines
- Front covers for oscillograph tubes
- Optical elements for light sensors
- Signal optics
Dimensions
Thicknesses
0.9mm – 10mm
Sizes
Up to 66" x 28" (1676.4 x 711.2mm)
Optical Properties
Index of Refraction @
546nm
1.5252
Index of Refraction @
588nm
1.5231
Electrical Properties
Log10 Volume Resistivity
(250°C, 482°F)
1 x 109 ohm*cm
Log10 Volume Resistivity
(350°C, 662°F)
1.6 x 107 ohm*cm
* Crown glass is a type of optical glass used in lenses and other optical components. It has relatively low refractive index (≈1.52) and low dispersion (with Abbe num- bers around 60). Crown glass is produced from alkali-lime (RCH) silicates containing approximately 10% potassium oxide and is one of the earliest low dispersion glasses.
Mechanical Properties
Density (25°C) ρ
2.55 g/cm3
159.2 lb/ft3
Young’s Modulus Ε
71.5 kN/mm2
10.4 Mpsi
Poisson’s Ratio μ
0.219
0.219
Knoop Hardness HK0.1/20
542
542
Bending strength σ
29.3 kN/mm2
4.2 Mpsi
Viscosity
Softening Point (107.6 poises)
724 °C
1335 °F
Annealing Point (1013 poises)
541 °C
1006 °F
Strain Point (1014.5 poises)
511 °C
991 °F
