Editorial: Shooting trouble and reinventing the wheel

Injection molding does funny things to people.

I was in a molding shop once on a visit with a consultant who was helping troubleshoot some molds. It was a multiday trip and on the morning of the second day the consultant and I were greeted on the floor by an obviously flustered and perturbed plant manager, who walked up to the consultant with accusation in his eyes. The exchange went something like this:

PM: That mold we fine-tuned last night and had working so wonderfully is now shorting in the third cavity! Consultant: Hmm. What changed?

PM: What changed? Nothing! It was running fine and now it’s not.

Consultant: Well, something must have changed. Let’s take a look . . .

PM: I’m telling you, absolutely nothing has changed. I checked everything myself. It’s just messed up. Gremlins? Aliens? Resin mites? Well, it turns out something did change. Someone, during the night, had changed the barrel heats. It was probably done in an attempt to get the process “back” to where that night-shift operator was used to having it, despite the fact that in-spec parts were falling onto the conveyor.

Injection molding does funny things to people because it’s a process based largely on faith. You can’t actually see the material in the barrel, melting as it churns forward. You can’t actually see the melt shooting into the mold and filling the cavities. You can’t actually see the water moving through the cooling channels.

Sure, you have instruments that reflect certain process conditions, but you don’t have direct evidence of a process at work except for the finished part. So, when something goes wrong, it’s easy to lose that faith. And it’s sometimes even easier to think that you’re the only molder in the entire history of molding who’s ever had the problem you’re having right now—that it’s a mystery beyond all human knowledge.

To understand how erroneous this is, spend a few minutes perusing the Networking Forum. You will quickly realize that there are no unique problems in molding. It’s an almost sure bet that the problem you’re having right now has been faced and solved by hundreds of people just like you. And the beauty of this industry is that you’re not on your own. Through devices like the Networking Forum, you can find a whole universe of knowledgeable, helpful, and friendly molders just like you who are trying to make good parts fast without losing their minds.

You don’t have to reinvent the wheel; you just have to know where to look for it. And remember, something must have changed.

Editor [email protected]