Physical properties

• P typically stands for ploly (as in polymer)
• Hydrolysis is when water breaks or shortens polymer chains.
• Hydrolysed filament pulls apart at the layers easier.

Keeping try

• Storing filament in a sealed container with a dessicant (salt cartridge) keeps moisture out of the filament.
• This will not pull moisture out of an already waterlogged filament.
• "PrintDry" sells storage containers where a top clamps on, and a vacuum pump slot exists to pull air out to prevent moisture.

Drying

• Ovens are not recommended because they can easily melt the plastic or release harmful offgas.
• Use of an oven: pre-heat the oven and wait for temperature to stabilize before inserting the filament. Preheat to 160-180F, cook spool for 4-6 hours. Remove from oven and place in sealed container with dessicant.
• There are also systems like a "PrintDry" which is a dedicated filament drying oven. And containers which have vacuum pump tops to keep filament sealed in.
• Food dehydrators are better than ovens; the dehydrator will not alter the properties of the filament.
• Make sure to check the melting points of your filaments; many users reported fusing their PETG at temperatures that were intended for ABS.