There has been recent interest in the Stratasys Nylon 12 3D Printing material. To showcase some of the features of this great product, we have put together Nylon 12 FAQ, usage tips and best practices information. Continue reading to learn more about this innovative material.
What is Nylon 12?
Nylon is classed as a PA (Polyamide) thermoplastic. It was initially developed in 1939 as a synthetic replacement for silk. It was used extensively in parachutes, flak jackets and vehicle tires. Today, the main use for Nylon is in automotive parts.
Stratasys Nylon 12 is an unfilled Nylon material. Some Nylons are classified as filled. This means they contain fibers that impart additional or improved material properties. The most common is glass filled Nylon, which contains glass fibers to improve the thermal and strength characteristics of the material. The number 12 in the material name indicates how many carbon atoms are in the molecule.
Why would I use it? What is it good for?
Nylon 12 has the following key material characteristics:
Good chemical resistance
Nylon 12 has good chemical resistance to most moderate solvents, alcohols and chemicals. It would be a good choice if you expect your part to be exposed to chemicals in either liquid or gas/vapor form. Refer to this document for chemical compatibility information. Of course, this document is only a guide to see if a given chemical is compatible – testing with a 3D printed material sample and the correct concentration of the chemical needs to be performed.
Moderate temperature resistance
Nylon 12 has a HDT (heat deflection temperature) of 55 °C (131 °F). The heat deflection temperature is the temperature when deformation will occur under load – so in most cases you will not want to exceed this. The HDT of Nylon 12 can be further improved to 82 °C (180 °F) through an annealing process performed after the part has been printed. Annealing is the process of baking the part in an oven for a specified duration. This causes changes in the crystalline structure of the material and, in this case, will improve the HDT. See below for the HDT comparison between Nylon 12, PC-ISO and PC-ABS materials.
Nylon 12 annealed = 82 °C
Nylon 12 = 55 °C
PC-ABS = 110 °C
PC-ISO = 133 °C
Any part that may be used in an environment where the temperature could approach the HDT should be thermally verified. Bearings or surfaces that are exposed to friction that could generate high temperature should be verified as well.
Nylon 12 has a tensile elongation of 30%. This is an indicator that this material is very flexible and tough. Tensile elongation expresses the capability of a material to resist changes of shape without crack formation. This means that Nylon can bend significantly more than materials with lower elongations before it will break. See the comparisons to PC and PC-ABS below.
Nylon 12 = 30%
PC = 6%
PC-ABS = 4.8%
You can see why PC is considered brittle compared to Nylon 12. Nylon 12 is ~5 times tougher than PC in terms of elongation at break. Nylon 12 is a great choice for any application that will be exposed to bending or twisting such as snap fits, friction fits, covers, handles, levers or shafts. It’s ability to resist cracking and toughness also make it a good choice for applications that require tapped holes or inserts.
High Fatigue Resistance
Nylon 12’s flexibility and good tensile strength gives it high fatigue resistance. Fatigue is caused by repetitive loading cycles or vibration and will eventually cause a part to crack and fail. If your part will be exposed to any type of vibration, such as a motor mount or any component used on a machine or vehicle, then this material would be the correct choice. Snap fits and press fits are also exposed to repetitive loading so Nylon 12 is ideal for these features as well.
Good Impact Strength
Again, due to the flexibility and toughness of Nylon 12, the material exhibits good impact strength. Impact strength is the capability of the material to withstand a suddenly applied load (impact) without cracking or permanent deformation. This is especially important with parts that can be dropped or require drop testing, such as any hand held device or jig/fixture.
Additional material strength and improved aesthetics can be achieved by modifying the part tool paths in INSIGHT. We will cover this in a future blog post, where we will discuss Nylon 12 printing best practices.
In review, we recommend Nylon 12 for the following applications:
- Panels, covers, housings with snap fits, bosses and other small features.
- Environmental ducting and control.
- Components or products with high vibration, repetitive stress or fatigue.
- Drill guides, cutting fixtures and prototypes with press fits and inserts.
- Prototypes or end use parts requiring tough bosses, tapping or threaded inserts.
- Parts requiring good impact strength such as hand held devices and jig/fixtures.
- Parts requiring good chemical resistance.
Due to the semi-crystalline nature of this material, there are additional factors to consider to ensure good part quality and build reliability. Stay tuned for Nylon 12 Spotlight Part 2, where we will discuss printing and part quality best practices to ensure success with your Nylon 12 projects.
Contact us to learn more about Nylon 12 FDM material, to order a sample part, or to determine what 3D Printing material is best suited to your application.