Nailono (PA, PA-CF) gijų džiovinimas ir laikymas: kodėl drėgmė gadina detales
Nylon (PA – polyamide) is one of the best filaments for functional spare parts: gears, bushings, sliders, brackets. But it has one quirk – it absorbs moisture from the air. Damp nylon filament crackles when printing, and parts come out with bubbles, rough and weaker than they should be. The good news: the problem is easy to solve once you know how to dry and store the filament.
Why nylon “fears” moisture
Nylon is a hygroscopic material – it draws water molecules from the surrounding air. A reel freshly opened from vacuum packaging is dry, but if left in open air it can absorb moisture within a few days, and even faster in a humid room.
When damp filament enters a hot nozzle (nylon usually needs 240–300 °C), the water instantly turns to steam. As a result:
- you hear crackling or popping – this is the first sign that the filament needs drying (as Polymaker also recommends);
- the surface becomes rough, with bubbles and pits;
- more “stringing” appears between parts of the print;
- layers bond worse – the part is weaker, and may split between layers;
- dimensional accuracy suffers.
For a functional part, this is the worst outcome: it looks neat, but breaks sooner than it should.
How to dry nylon filament
Always take the drying temperature and time from the specific filament manufacturer's technical data sheet (TDS) – different nylons and additives have different recommendations. For example, Polymaker Fiberon PA6-CF20 data sheet specifies: dry at 100 °C, for 10 hours.
| Method | Advantages | Things to note |
|---|---|---|
| Filament dryer | Simple; the reel can stay in the dryer while printing | Check that it reaches the temperature specified by the manufacturer – nylon needs more than PLA or PETG |
| Oven with accurate temperature | Reaches high temperatures | Household oven temperature can fluctuate – check with a thermometer; the reel housing must withstand that temperature |
| Printer heated bed | No extra equipment needed | Unreliable – the reel heats unevenly, and often isn't enough for nylon |
For some filaments, the manufacturer recommends printing directly from a heated dryer. For example, the Polymaker Fiberon PA6-CF20 and PA612-ESD descriptions state that the filament must stay in the dryer for the entire printing time.
How to store it so you don't have to dry it every time
- Airtight box with desiccant. A plastic box with a gasket and silica gel packs is the cheapest solution. Polymaker advises storing and using PA6-CF20 filament in a dry environment where relative humidity is below 20%.
- Humidity gauge in the box. Without one you won't know whether the desiccant still works. A simple hygrometer will do, e.g., UNI-T UT333.
- Vacuum bags. Suitable for longer storage – especially if you print nylon infrequently.
- Don't open the packaging in advance. The factory reel is usually in a vacuum bag with a desiccant – open it only when you are ready to print.
What about a part that has already been printed?
Nylon absorbs moisture, and so does the printed part. This is not all bad: moist nylon becomes slightly more flexible and impact-resistant, but less stiff. That is why manufacturers often list properties for both dry and 'conditioned' (moisture-saturated) parts in their data sheets. If stiffness and dimensional accuracy matter for your part, bear in mind that its properties will change slightly in use.
For some nylon filaments, the manufacturer also recommends annealing (cf. annealing) after printing – for example, the PA6-CF20 data sheet specifies 100 °C for 16 hours. Annealing dries the part, so afterwards it absorbs moisture from the environment again.
One more practical tip: if you print supports from the same nylon, Polymaker advises removing them before the part absorbs moisture – otherwise the supports may become stuck permanently.
Which nylon to choose
- PA12 (Devil Design) – pure nylon without fibre additives, suitable for sliders, bushings and more flexible parts.
- PA612-CF15 and PA12 + 15 % CF (Rosa3D) – with carbon fibre, stiffer parts: holders, jigs.
- PA6-GF25 – with glass fibre, for strong engineering parts.
Carbon fibre and glass fibre filaments are abrasive – they require a hardened nozzle. You can read more about this in our article 'Carbon fibre (CF) filaments: when worth it, what nozzle is needed', and find a comparison of materials in the article "Which filament to choose for spare parts".
Short checklist
- Before printing, dry the filament according to the manufacturer's TDS.
- Print from a drying box or a sealed container.
- If you hear crackling, stop and dry the filament.
- After work, put the reel straight into a sealed box with a desiccant and a hygrometer.
- Keep in mind that the printed part will absorb some moisture in use.
How to find them on inteq.lt
You can find all nylon and other engineering filaments in the category Filaments. In the search you can enter the manufacturer's code or upload a 📷 photo – the system will suggest a match and alternatives. If you are looking for a specific filament or are not sure which one will suit your part, send us an enquiry and we will find it.
