Polymer Profile: Elliot Carnevale, Technical Service Engineer | Injection Molding

It is quite common for injection molders to become comfortable running a specific resin and they often extend its use to multiple applications. But that can result in overengineered, more costly parts. I think there’s a real opportunity for converters to look at each application critically, and with an open mind, before deciding on what material is most appropriate.

Most injection molders experience some defects and processing issues and, when problems occur, it can be a mistake to look for a single cause. Engineers will typically hunt for a magic bullet and, when they find it, assume that it will solve all their future problems. In my experience, it’s far more likely the result of multiple variables combining.

In injection molding, shear has a far more significant impact on the flow behavior of a material than the temperature of the barrel. Higher shear generally means lower viscosity. So, consider your screw design, your injection velocity and the diameter of your flow channels.

If you are not already using simulation, it can be a hugely valuable tool because it avoids the need to iterate on the press. Instead, you get to understand the impact of different variables at the click of a button.