Polymers shrink and orient. Sometimes orientation is unbalanced, resulting in misshaped parts. But there are steps beyond tweaking the die that can mitigate these effects.


Flight widths are almost always designed at 10% of the screw diameter. But they can be optimized to reduce melt temperature and perhaps boost output.

EXTRUSION: Barrier Screws and Mixers

For some reason, there are a lot of barrier screws in operation with high-shear mixers, when a distributive mixer is usually a better choice.


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EXTRUSION: Barrier Screws and Mixers
For some reason, there are a lot of barrier screws in operation with high-shear mixers, when a distributive mixer is usually a better choice.
Columns Published: 8/17/2015

EXTRUSION: How to Adjust for Shrinkage and Orientation
Polymers shrink and orient. Sometimes orientation is unbalanced, resulting in misshaped parts. But there are steps beyond tweaking the die that can mitigate these effects.
Columns Published: 7/16/2015

EXTRUSION: Another Technique for Controlling Melt Temperature
Flight widths are almost always designed at 10% of the screw diameter. But they can be optimized to reduce melt temperature and perhaps boost output.
Columns Published: 7/1/2015

EXTRUSION: Cooling: The Critical Function in Extrusion
Figuring out how much cooling your process needs is complicated. But there are ways to approximate.
Columns Published: 5/25/2015

EXTRUSION: Here’s Why You Shouldn’t Run Your Extruders Dry
At least not for longer than a few minutes. The thin film that’s captured between the screw flights and barrel wall supports the screw and acts as a lubricant. Without it, galling can occur.
Columns Published: 4/27/2015

Extrusion: What’s the Best Way to Vent?
There are advantages and disadvantages to each, and they must be evaluated before making a decision.
Columns Published: 3/31/2015

EXTRUSION: Are Grooved-Feed Extruders Right for You?
In specific circumstances, this design can increase output and reduce melt temperature. But grooved feed throats are not for every application.
Columns Published: 2/22/2015


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