Nylon 910 (Taulman) and air moisture

[ultimprint 4]

Recently I have started to print with Nylon 910 and I was surprised that the air humidity moisten very quickly the filament. One day after the opening, I had already many bubble steam at the start of the print (not directly in the beginning but after about 1 minute).

The first layer wasn't good so I stopped all my prints... I tried maybe 10 times to start a perfect print and the number of bubble decreased with the number of test until disappear.

The next day I had exactly the same problem and I let the print carry on. The steam bubbles disappeared after 10 minutes. I heated a piece of filament with the bed until it reached 100°C and I let it cool down in the room where I have my printer.

When my piece was cold, I passed it through the nozzle, I had many steam bubbles. After that, I inserted a piece which was not heated through the nozzle and I didn't have any steam bubble.

My conclusion is when the Nylon filament is heated and cooled down, it absorbs the moisture... When you use the nylon 910, the best practice is to cut the piece heated or print a small thing just to use about 3 cm of filament.

When you heat up an entire spool to dry it, I think that you need to put the spool directly in a hermetic bag (when hot) and not let the spool cool down the spool otherwise you have opposite effect.

Someone have seen the same filament behavior?

Have fun!++

Edited October 12, 2016 by Guest

[avogra 68]

This is known behaviour of Nylons. They are all highly hygroscopic, so you have to keep it as dry as possible.

For storage, I put the spools in the plastic bags they came in, together with some extra desiccant bags and an indicator card. The cards have some spots that change color depending on humidity, I think, 10%, 30% and 50%. That helps me to know, if the spool is still dry enough.Then I put all that in an extra zipperbag.

For short prints (<2h) I don't care too much. For longer prints, I place the spoolholder and the spool into a bucket with cap and also put a bunch of desiccant bags into it.

For the dessicant bags, I found some, which change color when they are used up, so I know when to dry the dessicant in an oven or replace them.

What you say about the heated piece sounds interesting. I didn't have to dry the filament yet, but if I have to some time, I will take care of that

For the first part of the filament, which was heated by the nozzle: This should be only some centimeters right? Maybe just cut them off?

[ultimprint 4]

I knowed about the hygroscopic property of Nylon but I thought that would take many months, not few day^^

Yes you can cut some centimeters...

I bought some reusable desiccant bags, I look if it is reasonable to dry a moist filament with desiccant bags.

[meduza 191]

I read somewhere that standard nylon pellets left in air reach their max humidity in something like 13 hours... it is very fast indeed.