Melt Problems with LDPE and Colour additives

[Timbersteel]

Yes, I am curious as to whether or not anyone could have a clear idea on how colours continue to separate or cool in the screenchanger and the block adapter on a blown film extruder resuting in blowing chunks. I am having problems finding this information and anyone in my position, would Greatly appreciate some advice. It seems that when temps above 390 F these colours should have melted and mixed well, but once above those temperatures, severe problems arise. Could it be the supplier problems, LDPE resin problems, Junk rejected material, or just the extruder itself. It seems that at times that temps above 390 produce better frost lines, more visual, much more clarity to the film.

 

[unclesyd]

Make sure your screw is the correct design for LDPE and has the proper mixing design for what you are trying to accomplish.

If it is the right design are you running it under the design conditions?

What is your procedure/schedule for cleaning or purging the extruder?