Extrusion Know How

AC Drives Take Hold

With progress in electronics and the introduction of the flux vector drive using complex control algorithms, AC drives are now equal to or better than DC drives for most applications.

Film Extrusion

Telltale Temperatures

Here's how to get a 'feel' for a screw design without actually seeing it. And how to use this information.
#bestpractices #processingtips


Don’t Overlook the Feed Section

Most extrusion screw designers often do not design the feed section with the same rigor as other sections. This is odd since nothing goes through the screw that doesn’t first go through the feed section.

Extrusion Know How

Regrind and Melt Pumps

Changing levels of regrind can result in unstable output. If not set up properly, a melt pump can add to this instability—the opposite of the intended effect.


‘General Purpose’ = No Purpose

Such screws have no value in extrusion operations.

Extrusion Know How

The Scale-Up Conundrum

There are many methods used to determine scale-up based on output, but most designers do not scale the melting requirement along with the output.

Extrusion Know How

Understanding Screw Breakage

You might think you're over-torquing the screw, but more often than not bending is the reason.

PET Processing - Extrusion

Extrusion: Where's the Data? The Importance of Melt Strength in Extrusion

All extrusion processes depend to some degree on the melt strength of the polymer, and this property is generally a no-show on data sheets.


The Cause of Catastrophic Screw Wear

Erratic feeding can be the culprit. This is not uncommon when dealing with recycled material.


The Limits Of Compression Ratio

Don't rely just on this value during the screw design process.