I’ve come across with some research showing stronger PLA-FDM parts under tensile and compression stress in longitudinal and transverse directions than Injected Moulding of the same material, as showed in Measurements of the mechanical response of unidirectional 3Dprinted, SONG 2017 (see attached image)
And the conclusion of the reseach states that :
“3D-printed PLA is tougher than injection-moulded PLA. This is due to the layered
and filamentous nature of the 3D-printed material and the complexity that this
induces in the microscopic mechanisms of fracture.”
Most studies with ABS shows that air gap and lack of strength in filament bonding decreases strength* in FDM parts.
Garyg
2
I think this study is goofy and incorrect.
FDM process is in no way is stronger than injection molding.
FDM 3D printed parts are very good under compression.
FDM printing has a grain similar to plywood.
If parts are designed for FDM 3d printing, they can be equal to injection molded parts.
…
Just my 2 cents worth.
TypeR
3
Nice find!
However, that said, 3D Printed parts are usually weaker than injection molded parts. Mainly because basically no one prints their parts at 100% infill.
Injection molden is always 100% infill, but 3D prints are usually somewhere between 20% and 50%.
3D prints are usually strong in the X and Y axis, but weak in the Z-axis.
Also, 3D printed walls need to be thicker than injection molded parts because they will snap rather easily in the Z-axis direction.
TexRob
4
My MK2S PLA prints are incredibly strong. I just tried to break the foot off of one of those Save the Pangolins legs before throwing it away, and it took a pair of pliers to finally break the joint. I’m just saying, I’ve seen people with junk PLA prints that you can break by hand, that’s definitely not what I get.
