Is there such thing as HDPE filament and how does it print. I did an Amazon search on HDPE filament and got a ton of PLA hits and no HDPE which surprised me somewhat.
I’ve used HDPE in sheet form for cutting boards and other projects. Stuff if pretty durable
With HDPE being a strong and environmentally-friendly material, you might be wondering why it isn’t used more in 3D printing. Unfortunately, as a 3D printing material, HDPE currently leaves a lot to be desired.
Warping
HDPE has a tendency to warp while printing, leading to imprecise final objects. Unfortunately, while we can mitigate warping, it’s not avoidable as the issue stems from the chemical structure of HDPE. In simple terms, HDPE is composed of two different microstructures that don’t cool at the same rate, and this uneven cooling leads to warped prints.
Shrinkage
HDPE shrinks as it cools. If you don’t account for this during the design phase, you may end up with an object too small for its intended purpose. You can print a test object with HDPE, measure the shrinkage, and adjust your design upward accordingly, but this is still a less-than-ideal solution. This makes HDPE impractical for prints that need to fit together precisely, since you’ll have less control over the final shape than you would with other filaments.
Poor Self-Adhesion
While HDPE forms strong chemical bonds, that doesn’t equate to strong layer adhesion when printing, which will significantly impact the overall strength of the print. Several great 3D printer fillers can smooth out the rough layer lines and help with delamination, but be aware that by introducing new variables to an HDPE print, you may be affecting things like its buoyancy, watertightness, chemical resistance, and recyclability.
From Alll3dp.com