Extrusion Temp ≠ Printing Temp

An interesting phenomenon in 3D printing is that what you set your printing temperature at may not be what the temperature of your actual filament extrudes at.

We cover this in our Warping section in Material Science, but essentially it takes time for material to heat up. This means if you print faster than the hotend can melt your material, you will extrude at a lower temperature than what you set in your slicer.

Extrusion Temperature: The temperature at which the plastic exits the nozzle (in ˚C)

Extrusion Rate: The rate at which the plastic is extruded from the nozzle (in mm3/s)

This is why when you print really fast on a printer that does not have a very high flow hotend - you may need to set your printing temperature above manufacturer recommendations. If you extrude at too low of a temperature due to print speeds, you may get a part that has a matte finish, under extrudes, or potentially even clogs.