New Technology Opens a Predictive Window Onto Screw Wear

Despite their integral role in transforming pellets fed through the hopper into parts ejected from the mold, visibility into the performance, health and efficiency of screws is difficult to discern for many reasons, not the least of which being the fact they’re located inside a barrel.


Nordson Selling Screw, Barrel Business

Private equity firm Altair expects to close on acquisition during the first quarter of next year.

Extrusion Know How

What You Should Know About Miniature Extrusion Screws

Very small screws have become more common with the growth of additive manufacturing. Designing such screws requires balancing their output requirements with their torque strength.

Extrusion Know How

Extrusion: Important Polymer Melting Equations for Extrusion Processors

The more you know about what happens in a screw, the more you’ll be able to work with your supplier to optimize design.

Milacron Renews Partnership With Barr for Screw Technology

Milacron has extended its exclusive partnership to offer Robert Barr Inc. designed screws on new Milacron injection molding machines or as aftermarket add-on to existing presses.


Extrusion: How Much L/D Do You Really Need?

Just like selecting the extruder size and drive combination, the L/D should be carefully evaluated.

Sheet Extrusion

Nordson to Open Xaloy Tech Center in Ohio

Sixth new Nordson lab will open in Austintown, Ohio, at a newly built plant for Xaloy screws and barrels.

Pipe, Profile & Tubing Extrusion

Extrusion: Two-Stage Screw Offers Distributive, Dissipative Mixing

New design from Davis-Standard offers outputs comparable to barrier screws at lower melt temperatures.

Extrusion Know How

Barrier Screws: Not All Are Created Equal

Let’s take a deep dive into parallel and crossing types and see where each fit in.

Extrusion Know How

Why Barrel Temperatures Have a Small Effect on Melt Temperature

Extruders are not like ovens. Tweaking barrel-temperature profiles will not influence melt temperature all that much. Here’s why.


Simple Scale-Up Calculations for Melting

You can avoid complicated melting equations when designing or evaluating a screw by using simpler methods that can save time and provide good results.


Partner Sought for Commercialization of "Revolutionary" Extruder for Recycling

The cylindrical extruder developed by VTT could revolutionize processing of recyclable materials including plastics, textiles and food waste.

Sheet Extrusion

Extrusion: Compact Extruder Is Potent, Energy Efficient

Small-footprint machine reportedly uses up to 95% less energy/lb of material processed and can typically achieve dimensionally stable product within 20 min. of being turned on.


Unraveling the Complexity of Single-Screw Scale-Up

Variables such as shear rates, melting rate, residence time and conductive heating are all influenced in the scale-up.

Extrusion Know How

Telltale Signs of Screw Wear

Determining the cause of wear is the first step in eliminating it.


Screw Wear: Understanding Causes, Effects, and Solutions

Here’s how to find out what’s happening to your screw and what to do about it.

Extrusion Know How

Extrusion: A Simple Way to Evaluate Your Screw Performance, Part 2

A hand-held calculator and some basic equations can help determine whether your screw is up to snuff.


Extrusion: A Simple Way to Evaluate Extruder Screws

While there’s lots of data that influences screw design, processors usually don’t have access to it. So instead, try calculating drag flow to see if your screw is working properly.

Extrusion Know How

Extrusion: Barrier Screws: Metering Section or Not?

A barrier screw without a metering section can reduce output and increase melt temperature.

Extrusion Know How

Extrusion: Understanding Weld Failures

Hard-surfacing failures without evidence of burrs indicate possible weld bond issues.

Film Extrusion

What is Your Extruder Trying to Tell You?

Being in tune with your film extrusion equipment will allow you to identify issues before they start impacting production.

Extrusion Know How

Extrusion: The Role of Polymer Density in Screw Design

Density affects the mass flow rate, and energy transfer is based on mass, not volume. As a result, polymer density enters into practically every calculation in a screw design.

Injection Know How

Injection Molding: Are You Using More Than 65% Of Your Barrel Capacity?

If you are, you are inviting Murphy—as in trouble—to the party.

Extrusion Know How

Sizing the Barrier Gap

Here’s a less complex way to properly size the barrier gap for barrier screws.

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