Hello, I am new to this forum and hoping I may be able to obtain some good information. I work in plastic extrusion for sheet and was wondering if anyone knew about the blue and black specs phenomenon. It seems that everyone is aware of each of the issues, but no one has been able to find a "fix" per se. The black specs I understand to be degraded polymer, which can result from hot zones or aby checkit13 - Plastic Extruder Working Group