From lab to production,
providing a window into the process
-29-
How to Do It and Why?
I.V. has been used to determine molecular weight relying on the key assumptions of
isolated flexible linear chains. You can eliminate the hindrances of the expertise, laboratory
and solvents required for solution measurements. Improvements in process control are
achievable using capillary rheometry methods over solution measurements due to their
simplicity and quick turnaround.
IV correlation calculations are only enabled when IV is set to ACTIVE in the SETUP mode.
IV results are based on an empirical study that included various PET resins. A reference
material of known IV is needed to calibrate the melt indexer.
You must get an IV value for your material prior to testing.
Dry PET for 5 hours at 150 ºC, use 6 grams material per test, clean machine thoroughly
and run at a temperature of 285 ºC.
This option, if purchased
,
enables only at 285 ºC
1.) Clean the orifice, piston rod and barrel thoroughly. This is very important! Put piston rod
back into barrel until temperature has locked.
2.) Enable IV calculations under the Setup on the indexer. Note that a typical Pet test
temperature is to 285 ºC.
3.) Set the following parameters accordingly in EDIT mode:
Acceptable Methods: A, A/B, B
Melt time: 360 sec
Temperature: 285 C
Flag: 2.54 cm
Weight: 2160 kg
Note
: Always perform a purge run of a new sample’
Example Settings/Procedures for known MFI’s
IV
MFI
Flag Length
(cm)
Method A
Time
(seconds)
Pull Plug
(seconds)
1.081
8
1.27
60
NA
0.975
10
2.54
40
270
0.950
16
1.27
40
220
0.749
35
2.54
20
30
0.705
43
2.54
20
30
0.662
57
2.54
20
15
0.660
53
2.54
10
40
0.626
73
2.54
10
25
0.556
11
2.54
10
15
0.554
143
2.54
10
0
0.389
180+
2.54
5
0
P/N: M0726(3)
| Rev: 012020 | ECO: 51182
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