Nylon is a material known for its flexibility, toughness and abrasion resistance. This is a type of polyamide that has a high melting point and creates no odours when you print with it. 3D printing with a nylon filament is done when you want to make moving parts or simply, items that will last a long time. For example, the gears in RC gearboxes are made of nylon and they don’t require lubrication. While nylon isn’t the most popular 3D printing material, it’s still up there with the likes of ABS and PLA. Like any 3D printing filament, nylon is available in different grades and you need to know certain things before you start using it.
Types of Nylon Filament
This is the most commonly used grade alongside nylon 6/6. Both nylon 3D filament grades offer excellent tensile strength and hardness.
Nylon 12 has the same tensile strength and hardness as nylon 6 but it is thermally and chemically more stable than nylon 6. This nylon 3D filament grade can also keep its shape over a wider range of temperatures and doesn’t absorb as much water as nylon 6.
Nylon 618 & 645
What sets nylon 618 apart from 6 and 12 is its flexibility. 645 nylon is more transparent and more flexible than 618 and although it looks similar to 618, it is a little bit stronger.
How to Print With It
Depending on the nylon grade you are suing, the nozzle temperature of your 3D printer should be set anywhere between 220 °C and 270 °C. The bed temperature should be set between 75 °C and 90 °C at a print speed set of about 40 mm/ s. The print speed can vary from grade to grade. You will also need to set the extruder temperature between 225 °C and 265 °C and you may need an all-metal hotend. While you won’t need a cooling fan to print with nylon, you will need either a glue stick or PEI build surface.
Nylon is a material that is also prone to warping and to prevent this you need to have the proper bed surface. The best surface for this is a garolite sheet as it provides consistent results. Glass plates are also a great choice which when used with PVA glue stick can provide the adhesion necessary for a smooth printing experience. A garolite surface offers strong adhesion which can be used for thousands of printouts. But you’ll need to sand out the top of the garolite surface with sandpaper in order to remove blemishes and make for a more textured and even surface.
SLS (selective laser sintering) is the best way to print with nylon since SLS works by using filaments in the form of powder. The wall thickness when working with this printing technology is 0.7 mm and the layer height is between 80 μm and 120 μm. The tolerance setting is ± 0.3% (min: ± 0.3 mm).
You can also print nylon using FDM (fused deposition modelling) technology but you have to remember that an FDM nylon filament is always hygroscopic – absorbs moisture from the air. When the 3D nylon filament gets heated during printing, the moisture bursts and it can affect both the printing bed and adhesion layer. This is why you need to store it in a dry place and know how to properly dry the material before printing with an FDM printer.
How to Dry Nylon Filament?
Drying nylon can be done in three different ways. The first and proper way of drying nylon is with a filament dryer. This device is dedicated solely for the purpose of removing moisture from filaments. Although there are various types of filament dryers they are all simple to use. Just put the spool inside, set the fryer at the correct setting (this varies with every filament manufacturer) and let it do what it does best. After a while, you just need to remove the spool from the dryer and you’re good.
The most commonly used method is with an oven as it is also the easiest. You don’t need to find the proper setting for your type of nylon filament, just set the temperature at 80 °C and leave the filament for about 4 to 6 hours. The longer the filament sits in the oven the drier it will become. Remember to place the spool in the oven when the target temperature is reached and not a second before it.
Another great way of drying nylon using household items is with a food dehydrator. Much like the oven they too are very good at drying the filament and they are also more affordable than an oven. Set the filament at the same temperature you did with the oven (or the highest you have on the food dehydrator) and wait for around 4-6 hours depending on how dry you want it to be. If the temperature is lower than 80 °C then you’ll need to wait a little bit more.