Nylon (PA)

What nylon is good at

Prusa describes polyamide (nylon) as having excellent thermal and mechanical resistance: it is extremely abrasion resistant, has excellent layer adhesion, a low friction coefficient and a high melting temperature, and suits parts that need heat, chemical and mechanical resistance. Thick sections are strong while thin sections stay flexible. Prusa also calls it very hard to print and recommends it for experienced users. Its two main problems are warping (for plain polyamide) and moisture.

Water: the first thing to control

Prusa says nylon is highly hygroscopic and, stored badly, can absorb water weighing up to 10 percent of the filament's weight Rule of thumb. Prusa lists bubbles, uneven layers and a poor surface finish as the result. Treat an opened nylon spool as wet until you have dried it.

• Dry before printing. Prusa's general polyamide guidance is at least 4 hours below 90 °C Starting point. Polymaker gives 100 °C for 8 hours for PolyMide CoPA Maker spec. These differ, which is why the product's own figure wins.
• Store airtight with desiccant, as Prusa advises, and keep the spool dry while it prints on long jobs (a dry box that feeds the printer).

See Drying and Storing Filament and Wet Filament Symptoms.

Water also changes printed parts. Polymaker reports some PolyMide CoPA properties on specimens soaked in water at 60 °C for 48 hours, with an average moisture content of about 6 percent Maker spec, alongside dry-tested values. Expect a nylon part's properties to depend on the moisture it picks up in service.

Two makers, two sets of numbers

Setting	Prusa knowledge base (its polyamide profile)	Polymaker PolyMide CoPA TDS
Nozzle	285 °C Starting point	250 to 270 °C Maker spec
Bed	110 °C Starting point	25 to 50 °C Maker spec
Surface	Prusa's PA Nylon sheet for best adhesion	PC and textured PEI, glue when needed Maker spec
Cooling fan	Not specified	Off Maker spec
Enclosure	Helps greatly with warping	Closed chamber needed Maker spec
After printing	Not covered	Anneal at 80 °C for 6 hours Maker spec

The bed temperatures differ by more than 50 degrees. "Nylon" covers many polymers (PA6, PA11, PA12, copolymers such as CoPA, filled grades), so copy settings only from the data sheet for your product, then test.

Warping and the enclosure

Prusa says a high ambient temperature, such as an enclosure, helps greatly with nylon's warping. It also notes that carbon-fiber-filled polyamides warp much less, and that its PA11 Carbon Fiber can be printed without an enclosure. See Warping and Carbon, Glass and Wood-Filled Filaments.

Bed adhesion

Use the surface and adhesive the filament maker names. Prusa gets the best results for most polyamides from its dedicated PA Nylon sheet; Polymaker lists PC or textured PEI with glue when needed for CoPA. A brim gives corners more grip; see Brims, Rafts and Skirts.

Nozzle wear

Polymaker states that brass nozzle abrasion happens quite often when printing PolyMide CoPA, and highly recommends a wear-resistant nozzle such as hardened steel or ruby. Filled nylons are abrasive too. Check your product's data sheet; see Hardened Nozzles and Abrasive Filaments.

Ventilation

Prusa states that polyamides emit a strong odor and potentially dangerous ultrafine particles, and says to print in a well-ventilated room or in an enclosure. An enclosure contains fumes rather than removing them; see the ventilation notes in the ABS and ASA lesson. See FDM Emissions and Ventilation.

Post-processing

Polymaker recommends annealing PolyMide CoPA parts in an oven at 80 °C for 6 hours after printing Maker spec. Annealing is product-specific: anneal only when your filament maker gives a procedure, and use its temperature and time. Prusa also notes that pure polyamide is suitable for cold pulls to clean a nozzle.

Common failures

What you see	Usual cause	Where to go
Bubbles, uneven layers, rough walls	Wet filament	Wet Filament Symptoms
Corners lift, part lets go	Warping, wrong surface or adhesive	Warping
Extrusion thinning over time	Worn brass nozzle	Hardened Nozzles
Weak layers	Moisture or settings outside the maker's range	Poor Layer Adhesion