Specification
ards.
Non-toleranced numerical values are reference values of an average production quality.
Values marked with
do not apply to the type of glass or no values are available.
Requirements deviating from these specifications must be defined in writing in a customer agreement.
Date of release:
May 02, 00
Form 0050/6A
SCHOTT DESAG
PCE - TKT
B 270 Superwite
04.00/1
page: 1 to 14
S
Specification
Physical and chemical properties
1.
Optical properties
1.1
Refractive indices ( 20C )
Pretreatment of samples
n
g
1.5341
annealed at 40C/h
n
F
1.5297
n
F
1.5292
n
e
1.5251 0.001*
n
d
1.5230
n
D
1.5229
* 0.0003 upon request
n
C
1.5207
n
C
1.5203
Further refractive indices in UV and IR (reference values)
see annex
1.1.1
Abbe value
e
58.3 0.6
d
58.5
1.2
Transmittance data
1.2.1
Spectral transmittance
( )
1.2.1.1
( )
- curve
Plot of spectral transmittance
( )
for
d = 2.0 mm und d = 15 mm (
= 280 nm - 650 nm)
d = 2.0 mm und d = 15 mm (
= 280 nm - 2000 nm)
1.2.1.2
( )
- individual values in %
1.2.1.3
Edge wavelength (d = 2.0 mm)
Edge wavelength
C
(
= 0.46) in nm
312
Solarization refer to 6.2
Additional data
S
(
= 0.05) in nm
294
P
(
= 0.85) in nm
340
1.2.2
Luminous transmittance
v
1.2.2.1
Luminous transmittance as a function of thickness
vD65
in %
vA
in %
91.7
91.7
91.6
91.6
91.0
91.0
4.0
15.0
thickness in mm
see annex
see annex
see annex
2.0
SCHOTT DESAG
Form 0050/6B
PCE - TKT
B 270 Superwite
04.00/2
page: 2
S
Specification
Physical and chemical properties
1.2.3
Special transmittance values in % (d = 2.0 mm)
1.2.3.1
UV - transmittance
UVA
84
UVB
1.2.3.2
IR - transmittance
A
92.5
1.2.3.3
Radiant transmittance
e
1.3
Colour
1.3.1
Visual evaluation
disregard
1.3.2
Colorimetry (d = 2.0 mm)
D
65
x
Chromaticity coordinates (colour locus) are referred
y
to the namend Standard Illuminant according to
A
x
CIE 2-observer
y
1.3.3
1.3.4
General colour rendering index R
a
(d = 2.0 mm)
19
91.4
0.314
100
0.332
0.448
0.408
disregard
Form 0050/6B
SCHOTT DESAG
PCE - TKT
B 270 Superwite
04.00/1
page: 3
S
Specification
Physical and chemical properties
2.
Thermal properties
2.1
Viscosities and corresponding temperatures
Designation
Viscosity
Temperature
log
in dPas
in C
Strain point
14.5
511
Annealing point
13.0
541
Softening point
7.6
724
Forming temperature
6.0
827
Forming temperature
5.0
915
Forming temperature
4.0
1033
2.2
Transformation temperature Tg in C
533
2.3
Coefficient of thermal expansion
2.3.1
Coefficient of mean linear thermal expansion
in 10
-6
K
-1
for the indicated temperature range
(static measurement)
(20C-300C)
9.4
(20C-200C)
9.0
(20C-100C)
8.2
2.3.2
Coefficient of mean linear thermal expansion
in 10
-6
K
-1
for the indicated temperature range
(dynamic measurement)
(20C-100C)
7.8
(20C-150C)
8.4
(20C-200C)
8.8
(20C-250C)
9.1
(20C-300C)
9.4
(20C-350C)
9.6
(20C-400C)
9.8
(20C-450C)
10.0
(20C-500C)
10.3
Form 0050/6B
SCHOTT DESAG
PCE - TKT
B 270 Superwite
04.00/1
page: 4
S
Specification
Physical and chemical properties
2.3.3
Coefficient of mean linear thermal expansion
in 10
-6
K
-1
for the mentioned temperature intervals
(dynamic measurement)
2.4
Fuseability
Stress-free fusion with suitable SCHOTT DESAG lower
segments is possible.
2.5
Mean specific heat capacity c
p
(20C-100C) in J/ (gK)
2.6
Thermal conductivity
in W/ (mK) for the
indicated temperatures
= 24.5C
=
1
89C
= 127C
= 167C
2.7
Specific thermal stress
in N/ (mmK)
1.08
1.15
0.86
see annex
0.86
0.92
1.01
Form 0050/6B
SCHOTT DESAG
PCE - TKT
B 270 Superwite
04.00/1
page: 5
S
Specification
Physical and chemical properties
3.
Mechanical properties
3.1
Density
in g/cm
2.55
3.2
Stress optical coefficient C in 1.02
10
-12
m/N
2.7
3.3
Breaking strength
Admissible value for the bending strength
zul
of technically
annealed glasses as calculation basis (air) in N/mm
30
A higher mechanical strength can be realized by chemical
toughening according to the ion exchange procedure
(refer to annex 3.3.1) or by thermal toughening.
3.3.1
Chemical toughening
Processing temperature
in C
420
Processing time t in h
16
Compressive stress Ds as birefringence in nm/cm
7200
Penetration depth Nz up to neutral zone in m
48
Further information
see annex
3.3.2
Thermal toughening
Recommended minimum thickness d in mm for toughened safety
glass for building purposes according to DIN 1249 T10 - 1990
3.4
Youngs modulus E in kN/mm
71.5
3.5
Poissons ratio
0.219
3.6
Torsion modulus G in kN/mm
29.3
3.7
Knoop hardness HK
100
542
Form 0050/6B
SCHOTT DESAG
4.0
PCE - TKT
B 270 Superwite
04.00/1
page: 6
S
Specification
Physical and chemical properties
4.
Chemical properties
4.1
Hydrolytic resistance acc. to DIN ISO 719
Hydrolytic class
HGB 3
Equivalent of alkali (Na
2
O) per gram of glass grains in
g/g
170
4.2
Acid resistance acc. to DIN 12 116
Acid class
2
Half surface weight loss after 6 hours in mg/dm
1.4
4.3
Alkali resistance acc. to DIN ISO 695
Class
A 2
Surface weight loss after 3 hours in mg/dm
140
5.
Electrical properties
5.1
Dielectric constant (Permittivity)
r
at 1 MHz
7.0
5.2
Dissipation factor tan
bei 1 MHz
30 10
-4
5.3
Electric volume resistivity
D
in
cm
at the specified temperatures
5.3.1
D
for alternating current 50 Hz and 3 kHz
= 1260C
10.2
= 1386C
6.8
5.3.2
D
for direct current
= 250C
10
9
= 350C
1.6 10
7
= 400C
2 10
6
5.4
Temperature t
k100
in C for a specific electric
volume resistivity of 10
8
cm
301
Form 0050/6B
SCHOTT DESAG
PCE - TKT
B 270 Superwite
04.00/1
page: 7
S
Specification
Physical and chemical properties
6.
Other properties
6.1
Lead equivalent in mm Pb at 15 mm glass thickness for X-rays
Voltage
1
50 kV/0.16 mm Cu total filtering
0.24
Voltage
1
80 kV/0.16 mm Cu total filtering
0.32
Voltage 110 kV/0.40 mm Cu total filtering
0.33
Voltage 150 kV/0.70 mm Cu total filtering
0.27
Measuring and Test Procedures
For X-radiation (constant voltage) the lead equivalent is defined by
the total filtering specified in the table (refer also to DIN 6845).
The exposed area has a diameter of 50 mm. The absorption of
radiation in the sample piece is compared to lead absorbers of such a
thickness that the same attenuation of the dose performance is reached
in both cases.
As detector, a scintillation dosimeter (scintillator 44 mm diameter,
15 mm height) is used.
The measuring inaccuracy is 0.03 mm.
6.2
Solarization
Shifting of the edge wavelength
C
(
= 0.46)
after
UV-radiation in the direction of longer wavelength
2
Measuring and Test Procedures
The sample will be irradiated with a UV - F 400 floodlamp.
The irradiation time amounts to 7h; the distance between
floodlamp and samplefastening is 14 cm.
7.
Annex (diagrams, curves)
Form 0050/6B
SCHOTT DESAG
C
in nm
PCE - TKT
B 270 Superwite
04.00/2
page: 8
Form 0050/6B
04.00/1
Physical and chemical properties
Specification
Annex 1.1
PCE - TKT
B 270 Superwite
page: 9
Refractive indices of B 270 Superwite in relationship to the wavelength
Refractive index
n
300
350
400
450
500
550
600
650
700
750
800 850 900 950 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
2100
2200
2300
Wavelength
in nm
1,42
1,43
1,44
1,45
1,46
1,47
1,48
1,49
1,50
1,51
1,52
1,55
1,56
1,57
1,54
1,53
313
334
365
405
436
480
486
546
589
633
656
707
852
1014
1060 1129
1395
1530
1970
2249
x
1813
SCHOTT DESAG
Form 0050/6B
04.00/1
Physical and chemical properties
Specification
Annex 1.2.1.1
0
10
20
30
40
50
60
70
80
90
100
280
300
320
340
360
380
400
420
440
460
480
500
520
540
560
580
600
620
640
Wavelength
in nm
Spectral Transmittance
Type of Glass: B 270 Superwite
Thickness: 2.0 mm Thickness: 15.0 mm
Transmittance
in %
PCE - TKT
B 270 Superwite
page: 10
SCHOTT DESAG
Form 0050/6B
04.00/1
Physical and chemical properties
Specification
Annex 1.2.1.1
PCE - TKT
B 270 Superwite
page: 11
0
10
20
30
40
50
60
70
80
90
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
Wavelength
in nm
Spectral Transmittance
Type of Glass: B 270 Superwite
Thickness: 2,0 mm Thickness: 15,0 mm
Transmittance
in %
SCHOTT DESAG
S
Annex 1.2.1.2
Specification
Physical and chemical properties
Spectral transmittance
( )
in % for the named thickness
thickness in mm
in nm
1
2
3
4
5
6
7
8
9
10
15
20
25
30
300
35.1
13.5
5.2
2.0
0.8
0.3
0.1
0.0
0.0
0.0
310
60.0
39.6
26.1
17.2
11.4
7.5
4.9
3.3
2.2
1.4
320
76.0
63.4
52.9
44.1
36.8
30.7
25.6
21.4
17.8
14.9
10.9
5.4
2.6
1.3
330
84.2
77.8
71.8
66.3
61.3
56.6
52,3
48.3
44.6
41.2
34.6
25.0
18.1
13.1
340
88.0
84.9
81.9
79.0
76.3
73.6
71.0
68.5
66.1
63.8
59.6
51.8
44.9
39.0
350
89.8
88.4
87.1
85.7
84.4
83.1
81.8
80.6
79.3
78.1
75.1
70.4
65.9
61.8
360
90.6
89.9
89.2
88.5
87.9
87.2
86.5
85.9
85.2
84.6
83.0
80.4
77.8
75.4
370
90.8
90.4
89.9
89.4
89.0
88.5
88.0
87.6
87.1
86.7
85.6
83.8
82.0
80.3
380
90.9
90.4
90.0
89.5
89.1
88.6
88.1
87.7
87.2
86.8
85.4
83.6
81.7
79.9
390
91.2
91.0
90.7
90.5
90.3
90.1
89.9
89.7
89.5
89.2
88.6
87.7
86.8
85.9
400
91.3
91.2
91.0
90.9
90.7
90.6
90.5
90.3
90.2
90.0
89.5
88.9
88.2
87.6
410
91.3
91.2
91.1
91.0
90.8
90.7
90.6
90.4
90.3
90.2
89.7
89.1
88.5
87.9
420
91.4
91.2
91.1
91.0
90.8
90.7
90.6
90.4
90.3
90.2
89.6
88.9
88.3
87.7
430
91.4
91.2
91.1
91.0
90.8
90.7
90.6
90.4
90.3
90.2
89.4