3D Printed Nylon Chainmail

This intricate chainmail fabric is made from nylon, a modern departure from traditional chainmail materials of metallic bronze, iron and steel. Unlike traditional chainmail fabrics , which are made by joining metal links by hand and one by one, this chainmail has been made in one go by a selective laser sintering (SLS) 3D printing process. In this process, a high-energy laser is fired onto a bed of nylon powder, which is maintained at a temperature just below its melting point. Powder particles in areas spot-heated by the laser become fused together to form a lightweight, porous solid. This is carried out in layers to gradually build up the shape of the object. The small details and overhanging, interlocking shapes that you can see on this chainmail are made possible by SLS printing, because the upper layers are supported by the unfused powder. These geometries wouldn’t be possible using other 3D printing processes, such as fused filament fabrication (FFF). 

 

SLS printed parts straight out of the printer can be identified by their powdery, grainy texture, of similar roughness to medium-grit sandpaper. A quick blast of compressed air can remove most of the unfused powder which tends to stick to the surface of parts. The creamy shade of this chainmail is the natural colour of nylon without pigments added, but the porosity of SLS prints makes them very easy to dye after they have been printed. This is most commonly done by leaving the parts to soak in a hot colour bath; the liquid dye is soaked up by the porous nylon like a sponge. Additional coatings for SLS 3D printed components such as protective lacquering or waterproofing may be sprayed onto the parts, and they can even be electroplated with metals.

 

The process of SLS printing was developed in the 1980s and is used for low-volume rapid prototyping applications, such as architectural scale-modelling and aeronautical designs tested in wind tunnels. Aside from the greater geometrical freedom afforded by this technique, SLS printed parts are strong and stiff, and the process has been extended to a range of materials, including metals, glass, ceramics and composite powders. It’s also faster than most other additive manufacturing methods. The technology is currently limited by the available size of the build volume, the expense of purchasing and running the machines, and wastage of powder, since the materials can degrade over time when held at elevated temperatures in the printer.