Although chemically PA11 and PA12 are very similar polymers, they are two different terms that produce very different results, all due to a different carbon atom.
The growing popularity of multi-jet fusion 3D printing in the evolving digital age has inevitably sparked deep-seated curiosity involving the process.
One of the main questions for beginners, for example, is what exactly nylon PA11 and nylon PA12 are and whether there really are significant differences between the two.
What Is Nylon? The Define Of Nylon
Before we discuss the differences between PA11 and PA12, let’s talk about what nylon actually is to get a better overall picture of the structure. Developed by Wallace Carothers and first seen in 1935, nylon is a flexible, durable plastic material that was first used in the 1940s in the production of ladies’ stockings. Later adopted by the automotive industry for its frictional properties, the material became popular and today is the most commonly used material in traditional thermoplastic manufacturing.
In the world of multi-jet fusion 3D printing, nylon is once again the most commonly used material when creating products in this light. As for the PA abbreviation followed by a number, this helps the user to understand the number of carbon atoms in the diamine and diacid monomers in the material used. In fact, the carbon atom ratio is the very thing that gives nylon its unique characteristics.
What Are PA11 And PA12?
Starting with nylon PA11, a bioplastic polyamide powder made from renewable resources derived from vegetable/castor oil. Furthermore, it has only one manufacturer, and that is Arkema. On the other hand, nylon PA12 is a subtle synthetic power grown from petroleum-based materials and has several manufacturers, such as Arkema again and Evonik.
Based on the development method, PA11 clearly has a low environmental impact and can be produced without requiring several tonnes of non-renewable material. In addition, it has excellent heat resistance, is stable in light and weather and is impressively flexible. As for PA12, although less environmentally friendly, it can withstand sharp drops in temperature and remains strong even in periods below freezing. Overall, it is rigid, resistant to cracking and exhibits impressive long-term qualities.
The Differences Of PA11 And PA12
Based on the information above, you may have already considered your preferred PA option for your 3D printing needs. For example, if you want a high quality product without leaving a carbon footprint on the environment, then PA11 would be the best choice. Alternatively, if you need a product that is stronger and more resistant to cracking during drastic temperature changes, then PA12 is recommended. even with this note, although it has been touched upon a little above, here is a more transparent, breakdown of the differences between PA11 and PA12 for easy reference.
The Chemical Properties Of Nylon PA11
- Chemically resistant to elements such as hydrocarbons, ketones, aldehydes, fuels, alcohols, oils, fats, mineral bases, salts and detergents.
- Low water absorption
- Good heat resistance
- Low impact on the environment
- Less consumption of renewable resources
- Commonly used for functional prototypes for mechanical loading, automotive interior components, long-term mobile production (e.g. hinges) and parts families
The Chemical Properties Of Nylon PA12
- Chemically resistant to elements such as oil, fuel, hydraulic oil, grease, salt, solvents and water
- Noise and vibration suppression
- Excellent heat resistance
- High machinability
- High wear resistance
- Multiple manufacturers
- Preferred for fully functional plastic parts (e.g. gears) which are often used as replacements for common injection moulded plastics.
The 3D Printing Differences Of PA11 And PA12
Nylon (nylon), polyamide, was the first fully synthetic material for mankind, and is one of the most widely used plastics, covering almost every aspect of life, from what is worn to what is used, and is a very comprehensive material in terms of performance. Nylon itself is a semi-crystalline, thermoplastic material with a low annual flow at the melting point, making it a relatively ideal material for 3D printing.
- The most common nylon materials in industry and life are PA6 and PA66, both are short chain (6 carbon chain) synthetic materials, material strength, temperature resistance, aesthetics, corrosion resistance, etc. are excellent, PA6 crystallinity is not as good as PA66, melting point is also slightly lower, slightly stronger toughness, slightly better processing performance, the difference between the two is not great. Unfortunately, due to the high moisture absorption of the material (1.5%-2.8%), these two nylon materials are not very good 3D printability, an important goal for us is to provide customers with more options closer to the real use of the material, if a customer needs to use PA6 to print samples, we can achieve PA6 printing through industrial grade FDM equipment according to customer demand.
- Nylon PA12 is the most common 3D printing material, the HP nylon, high performance nylon and imported nylon we offer are all Nylon 12 by default, we also offer PA11 for 3D printing, PA12 was developed to replace most of the functions of PA11, so most of the properties are the same, all belong to the long chain nylon x (12 or 11 carbon chain), with good mechanical properties, electrical PA11 is more expensive, as PA11 is prepared from castor oil and PA12 is prepared from oil. From an environmentally friendly point of view, PA11 is undoubtedly more green and sustainable, using renewable biological resources, but the raw material price of PA11 is more than three times that of PA12. It has better high and low temperature properties, with a melting point 10 degrees higher than PA12, reaching 200 degrees, and a slightly higher working temperature than nylon 12 + glass fibre.
- At low temperatures, PA11 is significantly more flexible than PA12. An important difference between PA12 and PA11 and PA6(6) is the moisture absorption, which is only 0.25% for PA11 and PA12, 10 times less than PA6/PA66, making them easier materials for 3D printing Both SLS and FDM processes are sensitive to moisture absorption and shrinkage. The properties of PA12 and PA11 fall between PA6 and PE, with better toughness than PA6(6), and in some applications, such as electrical cables, PA6 may be too stiff and PA12 and PA11 are up to the task. However, PA12 and PA11 have lower melting temperatures, lower strength, lower dielectric properties and are more expensive, which is the main reason why PA12 is not as widely used as PA6 in actual industrial production.
One Less Carbon Atom Can Make A Huge Difference
Nylon is one of the most widely developed engineering thermoplastic materials available today and is heavily incorporated into HP multi-jet fused 3D printing. With this comes a variety of variations, including nylon PA11 and nylon PA12. Both options are excellent in their own way and can achieve a wide range of 3D printing goals. It is important to remember, however, that simply because both come from the same chemistry, they are very different. It is therefore important that you understand these potential differences in order to really improve your 3D printing goals and get favourable results every time.
In summary, from the low water absorption and dimensional stability of PA11 to the ideal impact properties and stress corrosion resistance of PA12, both are great, but be sure to do your due diligence and choose the one that best suits your needs for the best 3D printing success.