posted July 19, 2001 03:07 PM               

What are your opinions on the best method, and material to purge an extruder running PP (with a Melt Index of 8-12).

My thought was to use a PP with a melt index of 2-2.5. This line has been running a certain amount of coloured material, and may
not have been pulled apart for a while.

posted July 19, 2001 11:08 PM               

From my PVC experiences, I always liked to use a mild abrasive action with my PVC purge, to clean screws and barrels. Maybe your "stiffer melt" 2.0-2,5 MI PP could be enhanced with some 1-2 micron calcium carbonate, or some fumed silica to provide a "scrubbing" function??

posted July 20, 2001 08:06 AM            

You must have seen the discussion on purging and purge materials on the other site.

Ther are recommendations for purge materials, some of which are abrasive and some of which aren't.

Regards,

posted July 20, 2001 09:49 PM               

quote:

---

Originally posted by Steve H:
Hi Skip
The line in question has a Maag melt pump, and downstream from that a static mixing
adaptor. How would an abrasive cleaner
go on the melt pump bearings?

Steve

---

Steve,

I would think that if your melt pump and static mixer could handle 2-2.5 MI PP, it should be able to handle the same resin with calcium carbonate &/or silica.Melt viscosity would be somewhat higher, but you would get a definite cleaning action on all metal surfaces.

Regards,
Skip

posted July 13, 2005 11:44 PM               

Try Ultra Purge ready to use purge compound. It is non abrasive, uses base resins, and works great.

posted July 13, 2005 11:44 PM               

Try Ultra Purge ready to use purge compound. It is non abrasive, uses base resins, and works great.