Vol 17 #1, Feb. 1990 - Start up 1
When extruding a plastic material that is susceptible to degradation, it can be helpful to start running the clean extruder and die with a highly stabilized version of the plastic.
This will coat the extruder and die surfaces with a more degradation resistant material, and will reduce the chance of degradation problems. After 15 to 30 minutes, a switch can be made to the regular (not highly stabilized) plastic.
See also,
Melt blocking
Start up 2
Start up efficiency
Start up help
Start up timers