KNOW HOW - EXTRUSION

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The Three Causes of Screw Wear

You run the risk of wasting time and money by not understanding what’s causing your screws to wear.

Join the Conversation!

In this Tech Day session, experts Walter Smith of Nordson and Steve DeAngelis of Davis-Standard will speak about new developments in high-speed sheet extrusion and next-generation tooling.

Try This Approach to Clean Up Your Recycled Material

CO2 can be used as a totally “green” solvent to remove many kinds of contamination in recycled plastics without the need for toxic solvents.
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Extrusion: Solving Surging in Two-Stage Screws

This usually crops up when the two stages are not matched in output. The best solution is to install a pressure-adjusting valve at the discharge end of the extruder.

Understanding the Effect of Polymer Viscosity on Melt Temperature

Every processor should get hold of the viscosity curves for the polymers they use or contemplate using in their operations, and learn how to read them.
#bestpractices

Extrusion: Evaluating Screw Design for Multi-Material Recycling

Since many plastic products are made of a combination of materials with very different melting points, careful consideration must be given to designing screws when it comes time to recycle these products.

Extrusion: 'Melt-Blown' Fiber: What You Need to Know to Enter the Face Mask Market

Coronavirus pandemic has made extrusion processors curious about entering the face-mask market. But melt-blown fiber is very different from most other extrusion processes and requires specialized equipment.
#bestpractices

Extrusion: The Importance of Zone 1 Barrel Temperature

Tweaking the temperature settings of the first barrel zones may not yield the desired result. In fact, they may yield the opposite. Here’s why.
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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: 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.

Try This Lower-Cost Purging Method

You might be able to reduce purging times and save money by scheduling processing jobs in order of the increasing material viscosity. But to get started, you'll need shear rate/viscosity curves for your polymers.

How to Optimize Usage of Recycled Material

Processors need to “engineer” feeding properties similar to virgin pellets into their regrind to efficiently and economically utilize more of their scrap.
#bestpractices

EXTRUSION: Melting 101

Learn the basics on how polymer melts in a single screw. Barrel temperature plays less of a role than you might think.
#bestpractices #processingtips

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.
#bestpractices #processingtips #screws

What You Need to Know to Get into Coextrusion

Key considerations range from determining the right extruder sizes to tooling, matching material viscosities, and lots more. Take a look.

Extruder Alignment: Important, but Only Half the Equation

The other half? Aligning and supporting downstream equipment. Here are best practices.

Understanding Viscosity in Extrusion

Both the power-law coefficient and the consistency index must be considered to calculate viscosity.

Cooling the Feed Throat and Screw: How Much Water Do You Need?

It’s one of the biggest quandaries in extrusion, as there is little or nothing published to give operators some guidance. So let’s try to shed some light on this trial-and-error process.
#bestpractices

Barrier Screws: Not All Are Created Equal

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

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.
#bestpractices #screws

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.

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.

Telltale Signs of Screw Wear

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