Material Drying

[processtech]

Hello,Back again with another question, In material specification it may say to dry a material at a certain temperature for a certain period of time. Is there any way you can measure if the material is dry enough. Is there a measurement device to do this. Thanks

[rickbatey]

There are moisture analyzers. Most work as loss in weight so the data can be skewed as some plasticizers may flash off from heat.
I've used glass slides heated with hot plate. You add some plastic between heated slides and mash. Voids can be from moisture.
BTW- most suppliers double actual time requirements as a safety factor in case you have a weak drier.
Rick.

[brentb]

We have an OmniMark Mark 2 (Lost Weight) I questioned the data for reasons stated by Rick, especially for implantable biosorbable resins. We then bought a Computrac Vapor Pro. This is said to give Karl Fisher- like results without the KF drawbacks.
We have been doing side by side comparisons, and the jury is still out. So far results are very similar, but still must bias test more "challenging " resins.
If you want to quantify your moisture content (which can dictate how many resins run) do analyze. Here glass plates and hours/temps dried won't suffice.

KOM

brent

[jeffieg]

dewpoint should be -40 or lower, does your drier not give this info?

[rickbatey]

Jeffieg, At times you may see -40* listed on the drier. But that may not mean that the resin is dry. You need to be able to confirm actual moisture levels in the polymer.
Rick.