Sorry, I misspoke. Not Ultem, but garolite. I’ve printed well over 100lbs of nylon and the only two things I’ve had success with are heated glass with glue stick (55-60C), or garolite (with and without glue).
I think the glue fills in the tiny gaps in the weave of the garolite. You can get good results with raw garolite, but the larger the print, the more likely you’ll need some glue.
@Taylor_Landry I print nylon on gluestick on G10 (the fiberglass grade of garolite), works great.
Right, I meant garolite, not ultem
Here are some empirical results for (non-3D printed) nylon composites with short fibres.
Science and Engineering of Short Fibre Reinforced Polymer Composites
Page 100 shows some testing of the relative strengths of raw and reinforced polymers.
Nylon’s matrix strength of 74 MPa has been enhanced to over 200 MPa by reinforcing with short fibres. The mean length of the short fibres was about 0.8mm.
Perhaps more importantly, the critical length of the short fibres was around 0.6mm. I believe that the critical length is the minimum length to achieve any increase in strength.
The questions that then arise are:
1. What is the mean length and distribution of lengths for currently available formulations of CF filament?
2. With fibres of at least 0.6mm, does that mean a larger nozzle diameter is required to take advantage of any benefits?
It seems to be the case that current formulations may have fibres that are too short, and they just act to weaken, rather than strengthen, the polymer matrix.
But the possibilities look good - nearly tripling the strength using short fibres of around 0.8mm - it all depends on filament manufacturers putting in the R&D effort to reliably produce a useful filament.