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> Glass
microfibre filters |
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Whatman offers two types of glass microfibre filters
manufactured from 100% borosilicate glass: binder-free glass
microfibre that is chemically inert and binder glass microfibre.
These depth filters combine fast flow rates with high loading
capacity and the retention of very fine particle, extending into
the sub-micro range. Glass microfibre filters can be used at
temperatures up to 500°C and are ideal for use in applications
involving air filtration and for gravimetric analysis of
volatile materials where ignition is involved.
Whatman glass microfibre filters have a fine capillary
structure and can absorb significantly larger quantities of
water than an equivalent cellulose filter, making them suitable
for spot tests and liquid scintillation counting methods. The
filters can also be made completely transparent for subsequent
microscopic examination.
The particle loading capacity of a filtration system can be
greatly increased by using a prefilter. Whatman glass microfibre
filters such as GF/B or GF/D are ideal because of the low
resistance to fluid flow and high particle loading capacity.
Whatman Multigrade GMF 150 is particularly valuable for the
prefiltration of larger volumes and solutions that are normally
difficult to filter.
| Typical Properties of
Binder-free Glass Microfibre Filters |
| Grade |
Particle Retention*
Liquid (µm)
|
Air Flow Rate
(s/100 mL/in2) |
Basis Weight
(g/m2) |
Thickness
(µm) |
Wet Burst
(psi) |
Tensile MD Dry
(N/15 mm) |
| GF/A |
1.6 |
4.3 |
53 |
260 |
0.3 |
5.5 |
| GF/B |
1.0 |
12 |
143 |
675 |
0.5 |
6.4 |
| GF/C |
1.2 |
6.7 |
53 |
260 |
0.3 |
6.6 |
| GF/D |
2.7 |
2.2 |
121 |
675 |
0.3 |
6.4 |
| GF/F |
0.7 |
19 |
75 |
420 |
0.3 |
8.9 |
| 934-AH |
1.5 |
3.7 |
64 |
435 |
0.5 |
4.1 |
| QM-A |
2.2 |
6.4 |
87 |
475 |
1.5 |
7.3 |
| GMF 150 |
1.2 |
3.1 |
139 |
730 |
1.4 |
4.2 |
| EPM 2000 |
2.0 |
4.7 |
85 |
450 |
1.8 |
6.3 |
| *98% Particle Retention Rating. |
| Technical
Specifications of Binder Glass Microfibre Filters |
| Grade |
Binder |
Retention rate
to BS 4400
(%) |
Air resistance
at 1m/s mm water
column
|
Filtration time to: |
Weight
(g/m2) |
Thickness
(µm) |
| |
|
Herzberg
(s) |
Gurley
(s) |
|
|
| GF 8 |
inorganic |
99.00 |
700 |
80 |
8 |
75 |
350 |
| GF 9 |
inorganic |
99.97 |
700 |
120 |
20 |
70 |
350 |
| GF 3362 |
inorganic |
99.99 |
1000 |
120 |
25 |
130 |
500 |
| GF 6 |
inorganic |
99.97 |
1500 |
200 |
40 |
80 |
350 |
| GF 10 |
organic |
99.97 |
650 |
80 |
12 |
70 |
350 |
| GF 92 |
inorganic |
— |
— |
120 |
20 |
70 |
350 |
|
+32 (0) 16
58 90 45 
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50 90 45