Topic: Talc + ABS
I tried adding talc to ABS pellets at a 5% load, I was hoping to have a more warp resistant ABS (less shrinkage). It didn't go exactly according to plan.
The first thing that happened was filament started coming out much faster than it had been. Multiple times faster than the same plastic at the same temperature. Also, at the same temperature the plastic went from being 1.73-1.75mm to being over 2mm. Motor load also increased from .8A for the raw generic ABS to 1.1A when talc was added. Where things went wrong was I tried first reducing the cooling (no effect), then I tried increasing the drop distance (still oversized at max range for Filawinder sensor), and finally I tried increasing the temperature. Even at an increased temperature I continued to get vastly oversized filament with the talc, and the only apparent effect of increased temperature was even faster extrusion speed and higher motor load.
What I think is happening is the talc is conducting heat up the barrel more than plastic would. Higher temperatures are simply causing more melt further up the barrel thereby putting extra load on the motor. The plastic is cooling down faster after being extruded as well (giving off heat quicker) so I'm ending up with larger filament regardless of the higher temperature.
Perhaps if I tried with a nozzle that is even smaller than the default 1.6mm? Also, I believe the powder wants to fall down faster than the pellets, it doesn't entirely stick to them, so it might have a higher loading of talc than 5% where powder falls down into the hopper faster than the pellets. Any suggestions on how to make it stick/adhere to the pellets more?