I recently received this from an extruder manufacturing PP film… RB We are processing a 1.1mil 3-layer PP film with a random copolymer. Initially, we were processing at 210ºC with a kinetic COF (coefficient of friction) = 0.5 initially, and 0.2 after two weeks. Currently, if we process at 210ºC, we get a COF of 0.8, […]
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Routsis Training
Procedure for Measuring Screw Wear
As a follow-up to one of my recent posts, I received this question… Matt The problem we are encountering is the different opinions on how to measure the screw and barrel wear. Is there a procedure that is widely used throughout the industry to determine screw wear? My Response Regarding the screw – Most screw manufacturers […]
Applicable Training
During a recent seminar, an extrusion technician recently made this false statement… Technician None of the training out there applies to what my plant is doing. My Response I first asked him if his extruder had a barrel and screw… He said yes. I then asked about the barrel heaters, cooling fans, and temperature controllers… He […]
Measuring Screw Wear
A friend of ours recently asked this question about screw wear… Jim I can get maintenance to measure the screw, but their philosophy is that there’s no reason to do so. Typically we replace barrels and check rings, but do not know what the state of the screw is. I think we should know, and […]
Explaining Melt Flow Index
I receive this question very often, and feel it would be great for the blog… Larry Can you briefly explain melt flow index, and how processors use it? My Response Melt flow indexing is the most popular, and yet least accurate way to determine material viscosity. The melt flow index (MFI) is the measure of […]