I’ll share this here as well…I’m VERY impressed with Bambu Lab PET-CF (*Note PET-CF is NOT the same as PETG-CF):
I’ve spent the last few days experimenting with printing and annealing Bambu Lab PET-CF filament, which is incredibly heat resistant, yet still quite easy to print.
After watching Dr. Igor Gaspar’s (My Tech Fun) video on this filament, it became evident that annealing was absolutely necessary to achieve Bambu’s advertised heat deflection temperatures, however, I found that I achieved similar results to Dr. Gaspar’s oven annealing (2 hours @ 110°C) by simply “Lazy Annealing” my parts directly on the heat bed (which has much lower likelihood of part warpage).
In previous experiments I found I was able to achieve a consistent 90°C annealing temperature with the build plate set to 120°C and the parts covered with a foil wrapped filament box. My annealing process on this heat deflection test bridge was 3 hours @ 90°C started immediately after the print, followed by a slow (1-1/2 hour) cool down.
What you are seeing in the video is the heat deflection bridge, after being warmed to 425°F (218°C). After witnessing zero deflection with 2x 10mm nuts, I opened my oven and pushed down on the bridge with great force. I would have gone to a higher temperature, but the cardboard I was using as an insulator was starting to burn.
I hope this information is helpful. Heat bed annealing is really only practical for smaller parts, but the ability to retain dimensional accuracy is quite beneficial. After very underwhelming results with annealing Matter Hackers NylonX, annealed Bambu Lab PET-CF will be my go-to filament for anything going into an automotive engine bay application moving forward.
-Casey