PA12 Smooth - Nylon-12 powder

Nylon-12 is one of the many materials belonging to the group of aliphatic polyamides. Despite the fact that nylonss are one of the oldest groups of thermoplastic materials, their use has not only not declined, but has surpassed many other more modern thermoplastic polymers in almost all industrial sectors, from textiles to aeronautics.

Imagen 1: Nylon-12 Structure

Within the group of aliphatic polyamides, perhaps the most widely used materials are nylon-6 or nylon-6,6, due to their good mechanical, chemical and thermal properties. Despite the fact that PA12 has slightly lower mechanical properties than PA6 or PA6-6, it has become the most common material in 3D SLS printing mainly for two reasons: its lower melting point and its low hygroscopicity.

This last property is of great importance. One of the main general characteristics of polyamides is their great capacity to absorb water, except in the case of PA12 and PA11 in which the range is considerably less. During the 3D printing process the powder is heated to high temperatures, removing the hydration water during the process. A material with a high hygroscopicity will release high amounts of water during the printing process, reducing its volume and being able to interfere in the sintering process.

Image 2: Polyamides water absortion plot. Source: http://www.plastix-world.com

PA12 Smooth is a nylon-12 powder specially formulated by Sinterit for its Lisa and Lisa Pro printers. It stands out for its good value for money, its good mechanical properties and its resistance to chemicals and UV radiation.

Video 1: PA12 Smooth promotional video. Source: Sinterit

It has an ultimate tensile strength of 41 MPa with an elongation of 13%, as well as an impact resistance of 15 KJ/m², which makes it a highly versatile material. Furthermore, its low hygroscopicity makes its dimensional stability very good, especially in environments with high variations in temperature and humidity. It also stands out for its high reusability, as it requires only 26% refreshment material.

Image 3: Stress-strain curve for PA12 Smooth. Source: Sinterit

In addition to their good technical properties, parts printed with PA12 Smooth have an excellent surface finish. On the walls parallel to the XZ and YZ planes the average roughness (Ra) is 9.7 µm and the depth of roughness (Rz) is 54.2 µm, while on the faces parallel to the XY plane it is 6.5 µm and 31.6 µm respectively.

Image 4: Surface comparison between PA12 Smooth and PA12 Industrial. Source: Sinterit

The smooth surface finish is especially noticeable when compared with that of the PA12 Industrial powder by Sinterit.

Among the main applications of the PA12 Smooth powder we can find:

• The printing of models that require a high level of detail, both functional and mockup, such as architectural or engineering scale models, prototypes of jewelry and consumer products, functional tests of complex mechanisms, etc.
• Small series of products such as custom technical device housings, orthopedic products, or machinery parts.
• Instrumentation housings or protectors or devices that are subject to outdoor environments, chemical environments, etc.

All this makes PA12 Smooth the most versatile material in Sinterit, due to its balance between cost, surface finish and physico-chemical properties.