So when my Prusa I3 is heating up, a small bit of filament is coming out of the nozzle, forming a small string at.
When the printing starts, this results in a small plastic ball on the bed, impacting the overall printing process.
How can I avoid this?
On my Kossel Mini I programmed it to go to the edge of the bed and purge a small amount of filament which creates a dot. I purge enough to get the dot to stick to the bed and then go on with printing, when the head moves the dot stays attached and usually pulls excess material off the nozzle. This can be added to the "Starting G-Code" section of your slicer.