Material Science Part 2: Polyamide (PA 12) – A Boring Material or Actually a Game of Fire and Glass?

In Archive by Dorothée Doepfer

Do you like natural or colorful objects for a reasonable price? Does your model need to be flame resistant or has to survive high compressive strength? Then PA 12 is the most suitable material. Why? Then read here:

Polyamide 12 (PA12) – The Chameleon among the Nylons

The material PA 12 seems to me like a chameleon or some of the members of the House Lannister, characters in the worldwide known show ‘Games of Thrones’. PA 12 in its raw version is affordable and easy to handle, but by adding other components it appears to be expensive and very delicate.
PA 12 can be processed on fine layer thicknesses and it is post-processing friendly. Even though PA 12 is not as widely used as PA 6/6 it is known as a biocompatible, multipurpose material. It comes as a white powder as well, but its performance is much stiffer compared to PA 11, remember last blog article. As an add-on, it has a glass bead filled and flame retardant ‘brother’. 
Beside 3D printing PA12 is mainly used for films for packing material, in the food industry and for sterilized films and bags for use in the pharmaceutical and medical fields.

Find out here why PA 12 is the handyman for your model!

Advantages:

  • Minimal water absorption
  • High strength and stiffness
  • Extraordinarily high impact resistance (even well below freezing point)
  • Good resistance to greases, oils, fuels, hydraulic fluids, and many solvents as well as to salt solutions and other chemicals
  • Excellent resistance to stress cracking, even for metal parts encapsulated by injection molding or embedded into the plastic
  • Excellent long-term survival
  • Noise and vibration damping properties
  • Excellent resistance to fatigue caused by frequent load change
  • Easy processability

Limitations:

  • Lowest water absorption level in comparison to all other polyamides
  • Lesser flexibility in comparison to PA 11

Application Area:

  • Functional parts
  • Medical applications (e.g. prostheses)
  • Fully functional plastic parts of highest quality
  • Substitution for typical injection moulding plastics
  • Realization of movable part connections

Best Practice in 3D-Printing
PA 12 can be implanted in procedures e.g. stereolithography, fused deposition modeling and, of course, selective laser sintering (SLS) due to the following characteristics:

  • Suited to 90% of the designs
  • Strong material
  • Hard wearing
  • Flexible
  • Color-wise best results with matt coating
  • Can be combined with other materials e.g. glass or carbon
  • Excellent cost-performance
  • Wherever a high level of accuracy and detail resolution is required


Preferred for models such as:

  • Designs that need a very high level of flexibility and development
  • Prototypes that need mechanical strength or impact strength
  • Parts that need thermal stability or dimensional stability
  • Designs that need to be biocompatible

Extended PA 12 ‘family’ – Glass Filled Polyamide and Flame Retardant Polyamide


Glass Filled Polyamide (PA 12 GF or PA 3200-GF)

The use of PA powder which is generally filled with at the most 30% of glass particles (PA-GF) is typically used in functional tests with high thermal loads. It is available in natural color or black. Predominantly, PA 12 GF is used in the field of engines


Advantages:
In comparison to PA 12

  • Higher compressive strength
  • Higher rigidity
  • Much higher thermal resistance
  • 200% stronger
  • Excellent constant long-term survival
  • Excellent surface quality

Limitations:

  • Reduction of non-lubricated wear properties
  • Highly abrasive towards mating surfaces

Flame Retardant Polyamide (PA12 FR or PA 2241 FR)

PA12 FR is a flame retardant nylon which works via a halogen-based flame retardant and is predominantly used for aerospace applications (e.g. for flame resistant parts for the aircraft such like air ducts and air outlet valves). When the material is introduced to the conditions of a fire, it releases halogen that depletes the supply of oxygen to the flame and, therefore, extinguishes it. The powder is recyclable, i.e. it remains loose and not sintered after part production, and can be mixed with fresh powder and used in the next sintering process. PA 12 FR is available in natural color or black.


Advantages:
In comparison to PA 12

  • Flame-protected
  • Economical
  • High level of tensile strength
  • Enabling low-cost part production

Limitations:

  • Concern over the environmental toxicity due to halogen-based flame retardant
  • Limited accessibility

Read more about PA 6 and its newly-discovered use in 3D printing here on Thursday!

In case you have suggestions for other material which are important to you, let us know on twitter, FB or here as a comment. We will gladly include it in our material series.

For more information on materials read here:
Material Science Part 1: Polyamide (PA11) – Have You Ever Wondered What Nylons, Toothbrushes and 3D Printed Designs in SLS Have in Common?
Material Science Part 3: Polyamide (PA 6) – PA 6- Some Polyamides Like It Hot to Get in Shape
Material Science Part 4: ABS – PLA – the Magnificent Two
Material Science Part 5: Alumide – the ‘Hot Dog’ in the Polyamide Family
Material Science Part 6: Silver – The most precious of them all
Material Science Part 7: Ceramics – Not Only for Fine Art

Written By

Dorothée Doepfer

Hey, I am Dora and passionate to work at the interface of academia and old and new economy. I have been writing for quite a while now but with a focus on academic writing. I am looking forward to writing in a fresher style here. Besides working as a research manager at trinckle 3D, I am a vintage vinyl enthusiast and road trip addict.

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