John Bozzelli Founder

scientific molding 1 Aug 2018

Injection Molding: Fill Based on Volume, Not Weight

Most parts should be 90-99% full after first-stage—by volume not weight. Here’s why that’s important and how to make a first-stage-only part.

Injection Know How 1 Jul 2018

Injection Molding: Safety First—Know the Compatibility of Different Resins

Certain materials don’t play well together when mixed. So it’s best not to. Here are some guidelines.

processing tips 1 Jun 2018

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.

scientific molding 27 Apr 2018

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 Know How 29 Mar 2018

Injection Molding: How Backpressure Adjustments Influence Shot Size

Raising backpressure results in increasing shot size, which can cause a host of other problems.

Injection Know How 1 Mar 2018

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...

Injection Molding 23 Jan 2018

Injection Molding: Melting Amorphous vs. Semi-Crystalline Plastics

Understanding the differences in how each melts is crucial to obtaining melt uniformity.

technology in action 2 Jan 2018

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.

scientific molding 1 Dec 2017

Injection Molding: New Mold Trial—Will It Run 24/7?

Use this nine-step process to make sure you’ll be making good parts after a successful trial. But even then, be prepared for some hiccups.

processing tips 27 Oct 2017

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.

best practices 25 Sep 2017

Injection Molding: DOEs Done Right

Doing DOEs for the sake of doing them wastes time and money. But they can provide vital information to determine which process variable is determining a critical part characteristic.

Injection Molding 25 Jul 2017

Injection Molding: Time for Another Look at Non-Return Valves

First and foremost, they must seal properly, and check valves with stepped angles or radiused seats perform the best.

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