Thank you very much for the information Venkat.
As you well know, the fundamental purpose of a screen pack is to provide back pressure for the plastic in the extruder and thereby allow proper mixing and melt temperature stability.
Barrier screws also provide excellent back pressure and temperature stability in the mixing section of the extruder and thus, in this case, the importance of the screen packs is much reduced.
A second point is high shearing of the melt at the screen pack can generate a lot of heat which can in itself pre-cure the melt. A 300 mesh screen and two 150 mesh screens is a lot of screening.
How long could you run before cleaning out the extruders?
Thank you again.
Kindest regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com 
