Choose the right 3D printing process through material

The 3D printed material is usually of the filament type, powder type or resin type (depending on the 3D printing process used). Polymers (plastics) and alloys are the two main types of components for three-dimensional printing, while other materials (composites or ceramics) can also be used. We can further decompose the polymer into thermoset and thermoplastic materials.

If you know the materials you need, the choice of 3D printing process is relatively straightforward because only a few 3D printing processes use the same material to produce the part. In this case, choosing a 3D printing process is usually a comparison of cost and performance.

Thermoplastic:

Thermoplastics are best suited for functional applications, including the manufacture of end-use parts and the manufacture of functional prototypes.

They have good mechanical properties as well as high impact, chemical and abrasion resistance. They can also be filled with carbon, glass or other additives to improve their physical properties. 3D printing engineering thermoplastics such as PA, PEI and ASA will be widely used in end-use parts for commercial use.

SLS parts have better physical and mechanical properties and higher dimensional accuracy, but FDM is more economical and has a shorter lead time.

The pyramid below shows the most typical thermoplastic materials for 3D printing. According to experience, the higher the material in the pyramid, the better its mechanical properties and the more difficult it is to print, the higher the cost:

Thermosetting (resin):

Thermoset materials (resins) are more suitable for aesthetically demanding applications because they produce parts with smooth surfaces and fine details.

Generally, they have higher stiffness but are more brittle than thermoplastics and are therefore not suitable for functional applications. There are special resins that can be used in engineering applications (simulating ABS and PP properties) or dental implants.

Parts produced by material spraying typically have excellent dimensional accuracy and a smooth surface, but at a higher cost than SLA / DLP. Both methods use a similar UV curable acrylic resin.

Metal:

Metal 3D printed parts have excellent mechanical properties and can operate at high temperatures. The free-form features of 3D printing make it perfect for lighting applications in the aerospace and medical industries.
DMLS / SLM parts have excellent mechanical tolerances and properties, but Binder Jetting can be ten-times cheaper and may produce much larger parts.

Additional material:

Other materials can also be used for 3D printing, but they have not been widely used due to their limited applications .


Tips:

Due to the additive nature of this technique, 3D printed parts typically have anisotropic mechanical properties, which means they are weaker in the z-direction. For functional products, this feature should be considered when designing.