Everyone knows that nylon is hygroscopic right ?

It absorbs water from the atmosphere until it reaches an equilibrium point and that property can cause issues when 3D printing using nylon filaments. But what happens when you print a 3D form then immerse it in, lets say, a washing machine simulation?

The following photo shows a bunch of control forms, then the same design of form made from the same batch of the same recycled nylon monofilament. The second bunch has been immersed for 17 days continuously, exposed to sunlight (through a jar) and boil washed 10 times with a generous helping of a non-biological washing detergent called Surcare. OK, its not the harshest detergent in the world, but I hope you agree that this test scenario represents a good first go for any clothing related applications.

17 days and 10 boil washes

Left; Control form made of recycled nylon fishing nets and 3D printed. Right; Same material after 17 days immersed in detergent/water mix and including 10 ‘boil washes’

Some things to notice;

There is a slight bleaching of the original so we know that the detergent has been doing its job, but otherwise the nylon is showing is legendary resilience. There is no delamination, no cracking, no warping or visible deformation due to water ingress or absorbtion.

There is one key change though; flexibility.

Check out the clip.


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As you can see the second form is far more easily deformed under pressure. It springs back very well when pressure is released but there is a definite change in its deformability.

In fact, the ease of deformation rose rapidly to a peak after a couple of days immersion and stayed around the same after that suggesting that the material had reached some kind of equilibrium state.

As a control on our control, we’ve also printed the same form using the industry leading ‘open source’ nylon filament. There is little discernable difference in print quality or in a squeeze test carried out after 3 days atmospheric exposure.

Obviously 17 days and 10 boil washes isn’t enough to prove definitely that 3D printed nylon forms can be used in clothing applications, or indeed fisheries, marine or water management applications, but its a damn good start. And I’ll repeat my statement from a previous post that this is all done using a sub-£400 printer and pre-commercial filament.