I'm trying to make an evaluation of the available 3D printing options of polypropylene and I'm having difficulties comprehending material characteristics that make PP PP-like.
I realize this sounds a bit non-exact, but please bear with me. Polypropylene is very beneficial for this specific product because it handles repeated large plastic deformations very well and won't break. When you look at the material properties and compare them to other plastics for injection moulding, one characteristic stands out - elongation at break, which can be up to 150% or more for PP for injection moulding (this value is from a generic database, actual materials have similar values).
When I checked the HP's PP mateiral and Stratasys's Durus PP-like mateiral, their elongation at break was very low, around 20%, which is less than PA11 for SLS 3D printing.
Maybe elongation at break is not a good parameter to evaluate the response to large plastic deformation I mentioned. Maybe someone has more insight into this.
EDIT: I tested the PP printed part for bending fatigue. The part was printed on a HP fusion jet printer and the results are very similar to the injection molded part.