Injection Molding

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.

Injection Molding: How Backpressure Adjustments Influence Shot Size
Raising backpressure results in increasing shot size, which can cause a host of other problems.

Tooling: Hot Sprues—Mold a Disk or Not?
Having a hot sprue shut off against the parting line versus intentionally molding a thin disk has been the subject of controversy for many years.

Injection Molding: How to Set Barrel Zone Temps
Start by picking a target melt temperature, and double-check data sheets for the resin supplier’s recommendations. Now for the rest...

Tooling: Tunnel Gates for Processors, Part 2
What you need to know to overcome problems out on the production floor.

Injection Molding: Melting Amorphous vs. Semi-Crystalline Plastics
Understanding the differences in how each melts is crucial to obtaining melt uniformity.

Injection Molding: Nozzle Heaters & Thermocouples: A Case of Wiring Done Wrong
Incorrect placement of wires for these components frustrates molders and costs them money to boot.

Are You a Molding ‘Hot Shot’?
Submit your part to a brand-new addition to Plastics Technology’s Molding Conference: The first annual Injection Molded Parts Competition.

Injection Molding: No, Backpressure Does NOT Raise Melt Temperature
It’s a classic confusion between cause and effect. Melt temperature rises when screw speed is increased. Check out this data.

Materials: Cycle Time: Science vs. Rules of Thumb—Part 5
Let’s examine the behavior of semi-crystalline materials that never reach their glass-transition temperature as they cool.