Borosilicate Clear Glass
Physical data sheet
|
No. |
Physics performance
|
Numerical Value
|
Unit
|
|
1
|
coefficient of mean linear thermal expansion(20ºC;300 ºC)
|
3.3±0.1
|
10-6 K-1
|
|
2
|
Transformation Temperature
|
525±15
|
ºC
|
|
3
|
Softening point
|
820±10
|
ºC
|
|
4
|
Working point
|
1260±20
|
ºC
|
|
5
|
Density at 20ºC
|
2.23±0.2
|
g/cm2
|
|
6
|
Mean thermal conductivity(20ºC-100ºC)
|
1.2
|
W/m.K
|
|
7
|
Refractive Index
|
0.92
|
l
|
Chemical Composition in approximate weight %( main components)
|
Item . |
SiO2
|
B2O3
|
AL2O3
|
Na2O +K2O
|
|
%
|
81
|
13
|
2
|
3.08
|
Chemical Data:
Hydrolytic resistance at 98ºC ISO719-HGB 1
Hydrolytic resistance at 121ºC ISO720-HGB 1
water resistance Grade 1 Test method: ISO1776
Acid resistant Class Grade 1 Test method: ISO1776