Thermal Properties

Only the temperature fluctuates

A particularly low coefficient of thermal expansion is what makes BOROFLOAT^®glassremarkably resistant to high temperature levels. Our borosilicate glass is proven to stand up to high and fluctuating temperatures typical of applications such as high-performance lamps, cinema projectors and inspection panels for chemical reactors. Even with applications where rapid cooling down from higher temperatures is the requirement, BOROFLOAT^® glass easily passes the test. For example, the temperature difference between a hot panel center and a cold panel edge.

Key benefits:

Outstanding thermal resistance

Very good temperature stability
Excellent resistance to thermal shock
Can be thermally toughened
Can be thermally shaped (3D)

Thermal properties
Coefficient of Linear Thermal Expansion (C.T.E.) α _{(20 - 300 °C)}	3.25 x 10-6 K^{-1 *}
Specific heat capacity c_{p (20 - 100 °C)}	0.83 kJ/(kg·K)
Thermal conductivity λ _{(90 °C)}	1.2 W/(m·K)^-1
* According to ISO 7991.

Maximum operating temperatures
For short-term usage (< 10 h)	500 °C
For long-term usage (≥ 10 h)	450 °C

Viscosity of BOROFLOAT^® 33
Working Point (10⁴ dPas)	1270 °C
LITTLETON temperature / Softening Point (10^7,6 dPas)	820 °C
Annealing Point (10¹³ dPas)	560 °C
Strain Point (10^14,5 dPas)	518 °C
Transformation temperature (T_g)	525 °C