Each molecule in the molded product can have a different residence time. This variance is reflected in the Residence-Time Distribution, which you can learn how to determine below.
, Fimmtech Inc.
Advances in downstream extrusion equipment have boosted production control.
Learn the basics on how polymer melts in a single screw. Barrel temperature plays less of a role than you might think.
Your problem may be related to tooling, material, processing, or combinations thereof. Here’s how to find the root cause.
Gate size and shape—unlike gate location—don’t often get the attention they deserve. Many common assumptions about gate geometry deserve to be challenged
Just like selecting the extruder size and drive combination, the L/D should be carefully evaluated.
In injection molding, a seemingly minor change in a setpoint can have a significant impact on part quality and process robustness and repeatability. That’s why Scientific Molding focuses on process outputs, not setpoints.
Piston filtration offers many advantages over other systems. While pressure fluctuations could be regarded as their weakness, there are many ways to avoid them, both from the mechanical and the process side. Small adjustment can make a huge difference in the overall performance and efficiency of the system.
There are many reasons why off-center gates happen, and processors should be aware of all of them to quickly find the ones causing the problem.
Implementing a production monitoring system as the foundation of a ‘smart factory’ is about integrating people with new technology as much as it is about integrating machines and computers. Here are tips from a company that has gone through the process.
Which pelletizing system is right for your application? Is the one you’re using today necessarily the right choice for tomorrow? Here’s is an analysis that can help you decide among the three major options.
Understanding the concepts of pack and hold and applying them during process development is critical for molders to achieve consistent part quality.
To make identical parts, you need to keep fill time constant. In part one we covered the why. Here’s the how.
That is the question pipe and tubing processors typically confront when they specify a line for one product, only to have to add to the product mix when business conditions change. Here are some tips to guide you to the right answer.
To make identical parts, you need to keep fill time constant. Here’s why.
It’s the processors job to ensure molded parts contain enough stabilizer to perform to the expectations of the end use.
Gels…unmelt…contaminants…inclusions…whatever you call them, you want to avoid them. Proper maintenance and good housekeeping—lids on boxes, closed hopper doors, core-free reclaim systems—go a long way towards defect-free product.
Use drag- and pressure-flow equations to analyze fluctuating output.
The locking-ring style appears to dominate the market, as most believe it makes a make a better seal and leaks less. But is this really so?
How to establish molding conditions that minimize internal stress in a part.
Determining the source of streaking or contamination in your molded parts is a critical step in perfecting your purging procedures ultimately saving you time and money.
Scientific molding is centered around learning about key molding principles and theories. The strategic application of those principles and theories is what’s known as systematic molding.
Here’s how to find out what’s happening to your screw and what to do about it.
While considered acceptable in many cases, they need not be tolerated and are usually attributable to minor screw-design flaws. Here’s some advice on what to do about them.
Molders tend to think about the elements of a melt-delivery system, from screw to hot-runner gate, in isolation from each other. But taking an integrated view of the whole system can have big consequences for cycle time, part quality, scrap rates, and energy consumption.
You rightfully worry about melt temperature, but don’t overlook head pressure, because the two are closely linked and will influence line performance.
A case can be made for multiple variables—fill balance, fill time, injection pressure, cavity pressure—as most important. But there is something else altogether that is essential to successful injection molding.