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10.3 CHIP SIzE
The polymer chips must be ground to fine powder (<0.5mm) using the polymer chip grinder.
10.4 DRYING PRINCIPLE
Weigh out 3.6g of polymer powder and transfer to a sample drying tube (glass phial).
High IV polymers (>0.7) are dried under vacuum at 170ºC for 55 minutes.
Low IV amorphous polymers (<0.7) are dried under vacuum at 170ºC for 50 minutes.
Too short a drying time will result in the sample still being wet and so degrade in the test giving low
results.
Too long a drying time will result in the sample starting to polymerise.
NoTE: The above values are guidelines based on the experience of many users.
Adjustment to temperature and drying time may be required to get the best and most
repeatable results.
10.5 USING THE POLYMER CHIP GRINDER
The Polymer Chip Grinder is designed to grind polymer chips down to particles of either 1mm or
0.5mm using the supplied grinder bowls.
Davenport recommends only using the 0.5mm bowl for the purposes of grinding polymer chips to
powder.
The polymer grinder should only be used for the purpose for which it was designed, as an accessory
to the Davenport PET Plus, as described in this operating manual.
Compressed air is used to drive the Polymer Grinder. Setting up, maintenance and service should
only be carried out by trained technicians or service personnel.
WARNING: The blades of the Polymer Grinder rotate at very high speeds. Therefore they
continue to rotate for a few seconds after the timer has operated or the Timer Valve knob
is pulled.
WAIT FOR 5 SECONDS BEFORE OPENING THE GRINDER AFTER IT HAS BEEN
SWITCHED OFF.
NOTE THAT PULLING THE TIMER VALVE KNOB FORWARDS STOPS THE GRINDER
AT ANY TIME.
60 PET Plus User Manual
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