Borosilicate glass Suprax 8488
Characteristics of the borosilicate glass SUPRAX 84488 
Thermal extension: a20/300 = 4,3.10-6 /K
Transformation temperature: 540°C
Density: 2,3 1 g/cm3
Modulus of elasticity: 67000N/mm2
Poisson's ratio m: 0,20
Specific thermal stress w=: 0,36 N mm-2 K-1
Thermal conductivity l at 90°C: 1,20 W m-1 K-1
tk100 (DIN 52326) : 200°C
Logarithm of the electrical volume resistance in V.cm
at 250°C 7,1
350°C 5,8
Dielectrical properties for 1 MHz at 25°C:
DZ 5,4
tand (10-4) 96
Refractive index nd (l=587,6 nm): 1,484
Stress-optical constant: 3,2.10-6
Chemical resistance
Resistance to water (ISO 719): Hydrolytic class 1
Resistance to acid (DIN 12116): Acid class 1
Resistance to alkali (DIN ISO695): Alkali class 2
Transmittance:
Comparison of various attacks to borosilicate and soda-lime glass
Chemical studies showed that borosilicate glass is ten times less subject to erosion than soda-lime glass, at a low pH value (pure water) as well as at an increased pH value (10). The divergence is considerable and starts already at 134°C. To illustrate this, the figure shows the erosion at a temperature of 150°C.
[from: “VGB Kraftwerkstechnik“, Dr. A. Peters, Feb. 1979]
Abb. Erosion of borosilicate and soda-lime glass in the liquid phase at 150°C. Water exchanged pH 6 and pH 10
(Suprax 8488 is a registered trade mark of the Schott group)
AR-Glass
AR-Glass® is a transparent glass that achieves water resistance class 3. It is a soda-lime glass with a high proportion of alkali metal oxides and alkaline earth metal oxides.
Characteristics of AR-Glass
|
Thermal extension: | a20/300 = 9,1.10-6 /K |
Transformation temperature: | 525°C |
Density: | 2,50 g/cm3 |
Modulus of elasticity: | 73000N/mm2 |
Poisson's ratio m: | 0,22 |
Thermal conductivity l at 90°C tk100 (DIN 52326) 200°C | 1,1 W m-1 K-1 |
Logarithm of the electrical volume resistance in V.cm at 250°C |
7,1 5,7 |
Dielectrical properties for 1 MHz at 25°C DZ 7,2 Refractive index nd (l=587,6 nm) | |
1,514 | |
Stress-optical constant: | 2,7.10-6 |
Chemical Resistance
Resistance to water (ISO 719): Hydrolytic class 3
Resistance to acid (DIN ISO 12116): Acid class 1
Resistance to alkali (DIN ISO 695): Alkali class 2
B270
Characteristics of B 270 Superwite®
(B270 Superwite® is a registered trademark of the Deutsche Spezialglas AG)
B 270 Superwite is a colorless and highly transparent crown glass, melted from completely clean raw materials.
This type of glass has a particularly high transmittance in the visible wavelength, IR and UV range.
B270 meets the requirements of the US-FDA (Food and Drug Administration) concerning food contact substances (FCS). It also meets the requirements of the US Pharmacopeia for "parenteral use" (glass type III).
Thermal extension: a20/300 = 9,4.10-6 /K
Transformation temperature: 533°C
Density: 2,55 g/cm3
Modulus of elasticity: 71500N/mm2
Poisson's ratio m: 0,219
Refractive index nd (l=587,6 nm): 1,5251
Chemical resistance
Resistance to water (DIN ISO 719) HGB 3 hydrolytic class 1
Resistance to acid DIN 12116) acid class S2
Resistance to alkali (DIN ISO 695) alkali class A2
Quartz glass
Characteristics of quartz glass
Quartz glass is a one-component glass (SiO2). It is one of the most valuable materials for both science and industry. There is a distinction between synthetic and natural quartz glass. Synthetic quartz glass is made from pure silicon tetrachloride (SiCl4) following the Flammpyrolyse-method. The raw material of quartz glass is a natural crystal mined from the earth as rock crystal or pegmatite quartz. The raw material is pulverized to a fine-particle granulate and melted to quartz glass in an oxy-hydrogen flame.
Quartz glass features
- good transmission behavior in ultra-violet, visible and infrared wavelengths
- high temperature endurance
- a low coefficient of thermal expansion
- good thermal shock resistance
- excellent electrical insulation
- high chemical purity
- a maximum operating temperature of 1100°C (permanently), or 1300°C (short-time)
Thermal extension: a20/300 = 5,1×10-7 K-1
Density: 2,2 g/cm3
Modulus of elasticity: 70000 N/mm2
Poisson's ratio m: 0,17
Compressive strength: 1150 N/mm2
Tensile strength 50 N/mm2
Bending strength 67 N/mm2
Thermal conductivity lw (20-100°C) 1,38-1,46 W m-1 K-1
Logarithm of the electrical volume resistance in V/cm
at 20°C 20
100°C 18
600°C 12
1000°C 8
Dielectrical properties for 1 MHz at 25°C
DZ 3,7
Refractive index nd (l=587,6 nm) 1,459
Stress-optical constant 3,57×10-6 N -1
Chemical resistance
Resistance to water (DIN ISO 719): HGB 1 Hydrolytic class 1
Säurebeständigkeit nach (DIN 12116): class 1
Laugenbeständigkeit (DIN ISO 695): class 1
Use
- high-temperature processes (high temperature resistance)
- semiconductor- and light-industry (purity)
- optics (good light transmission in visible, UV and IF wavelengths)
- laser technology
- electronics and electro-technology (low conductivity, high penetration field strength, low dielectric loss factor)
- chemistry and pharmaceutics (chemical resistance, not hygroscopic, chemical purity, thermal shock resistance)