Nylon is the polymer of choice for printed parts that have to work rather than merely exist. It is tough, it resists fatigue in flexure, it survives contact with most shop chemicals, and in sintered form it produces parts consistent enough in every direction to test with. Its one awkward property is that it absorbs water, which changes both its size and its behaviour.
Sintered against filament
Powder sintered nylon is heated close to its melting point throughout the chamber, so parts are dense, need no supports and behave similarly in every direction. Filament nylon is extruded, so it carries the layer bonding weakness of every filament process, and it warps as it prints. Where the part has to perform, sintered is the safer purchase.
What it is genuinely good at
Snap fits that snap and keep snapping. Living hinges. Clips, latches and catches. Gears and bushings, because it is self lubricating enough for light duty. Housings that get dropped. Shop fixtures that get knocked about. It is the material that lets a printed part be tested rather than merely looked at.
Moisture, and why it matters
Nylon absorbs water from the air, and as it does it grows slightly and becomes tougher and less stiff. Dry nylon is stronger and more brittle; conditioned nylon is more resilient. That means dimensions drift after printing and mechanical test results depend on conditioning. Filament must be dried before printing or the print bubbles and strings.
Filled grades
Glass filled nylon is stiffer and more dimensionally stable at the cost of toughness. Carbon filled nylon is stiffer again and lighter, and both abrade nozzles so a hardened one is required on filament machines. Aluminium filled sintered nylon gives a metallic appearance and better stiffness. Choose filled grades when stiffness matters and unfilled when impact does.
Questions people ask about nylon 3d printing service
Why is nylon used for functional printed parts?
Because it is tough, fatigue resistant in flexure and chemically resistant, and in sintered form it behaves consistently enough in every direction to test with.
Does printed nylon absorb water?
Yes, and as it does it grows slightly and becomes tougher and less stiff. Dimensions drift after printing and test results depend on conditioning.
Sintered or filament nylon?
Sintered for functional parts, because it needs no supports and has no weak layer bonding. Filament nylon is cheaper and carries the usual anisotropy.
Should I use a filled nylon?
Filled for stiffness and dimensional stability, unfilled for impact resistance. Filled grades abrade nozzles, so filament machines need a hardened one.