Know-How
The Fundamentals of Polyethylene – Part 2: Density and Molecular Weight
PE properties can be adjusted either by changing the molecular weight or by altering the density. While this increases the possible combinations of properties, it also requires that the specification for the material be precise.
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Understanding the Effect of Pressure Losses on Injection Molded Parts
The compressibility of plastics as a class of materials means the pressure punched into the machine control and the pressure the melt experiences at the end of fill within the mold will be very different. What does this difference mean for process consistency and part quality?
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The Fundamentals of Polyethylene – Part 1: The Basics
You would think we’d know all there is to know about a material that was commercialized 80 years ago. Not so for polyethylene. Let’s start by brushing up on the basics.
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How to Start a Hot-Runner Mold That Has No Tip Insulators
Here's a method to assist with efficient dark-to-light color changes on hot-runner systems that are hot-tipped.
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Maximize the Cooling Capacity of Your Extrusion Line
Maximizing output in extrusion requires a thorough understanding of not only the cooling requirements of the extruder but of the extrudate as well.
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How Polymer Melts in Single-Screw Extruders
Understanding how polymer melts in a single-screw extruder could help you optimize your screw design to eliminate defect-causing solid polymer fragments.
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Unraveling the Science and Myth Associated With Moisture Analysis— Part 1
The first task in moisture measurement is to purchase an instrument that is based on sound fundamentals. Then, before it goes into use, method development must be undertaken for all polymers that are going to be processed in the plant.
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Improve Production Rates Via Screw Design — Barrier vs. General Purpose vs. Melt Uniformity
I’m looking for a few good molders to help trial a new screw design, and share data and results for a future article to prove the benefits of a melt uniformity screw.
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How to Design Three-Plate Molds – Part 3
There are many things to consider, and paying attention to the details can help avoid machine downtime and higher maintenance costs — and keep the customer happy.
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Is a Gear Pump Right for Your Single-Screw Operation
As with everything else, there are pros and cons, but more of the former. They provide processors higher rates while decreasing the temperature of the extrudate while enabling downgauging.
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