Know-How
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.
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Injection Molding: Process Documentation Is Crucial to Making ‘Identical’ Parts
Use a machine/mold setup sheet to document plastic parameters and use them on any acceptable machine into which the mold is placed.
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A Processor's Most Important Job, Part 6: Long-Term Effects
The importance of mold temperature to the development of the desired polymer crystalline structure becomes absolutely crucial in the case of high-performance materials.
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Tooling: Clamp Pressure and Cavity Land Area
What you need to know to prevent flashing and mold damage.
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Extrusion: Barrier Screws: Metering Section or Not?
A barrier screw without a metering section can reduce output and increase melt temperature.
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Injection Molding: A Practical Approach to Calculating Residence Time
Toss the formulas. The best way to determine residence time is to conduct a simple experiment.
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A Processor's Most Important Job, Part 5: POM Polymers
Using a mold temperature above a polymer’s Tg ensures a degree of crystallinity high enough to provide for dimensional stability, even if the part must be used at elevated temperatures. But POM is an exception. Why?
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Tooling: What You Need to Know About Jump Gates
Many molders don’t care for jump gates because they have to process around them. But here are some tricks of the trade.
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Extrusion: Why There Are No Truly Universal Dies
Flow characteristics of different polymers vary considerably. So while adjustment features are available, for the most part dies must be designed for an individual polymer.
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Injection Molding: How Backpressure Adjustments Influence Shot Size
Raising backpressure results in increasing shot size, which can cause a host of other problems.
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