As the plastics industry grapples with solutions for a circular economy, low-constant-pressure molding is stepping up with breakthrough advances to run difficult sustainable materials, reduce energy use and offer design flexibility to lightweight parts.
Developed by Hamilton, Ohio-based Imflux Inc., a software and engineering firm that is subsidiary of Procter & Gamble, the processing software called Imflux uses low pressure and low heat to mold while taking advantage of the way polymers flow.
It's essentially the opposite to conventional high-pressure, fast-fill injection molding. The process is less abusive to the polymers, has lower shear rates and expands the capabilities of injection molding machines to run more post-consumer recycled content (PCR), according to Imflux Chief Technology Officer Gene Altonen.
Imflux has been partnering with machine builders, starting with Milacron in 2018, to integrate the processing technology into presses. The subsidiary also has strong partnerships with JSW and Haitian and is collaborating with more than 20 other machine maker OEMs to make Imflux broadly available to injection molders around the world.
In one demonstration at K 2022, a Milacron injection molding machine is producing custom krinkle bags made from PCR with different viscosities selected by trade show attendees.
"We're letting people make their own batch. They can mix whatever blend they want between a 14 melt flow index (MFI) and a 65 MFI, so there's a very big swing in viscosity. They feed it in and make their own unit," Altonen said. "We're showing the versatility of the system to adapt to whatever viscosity you throw at it. It recognizes the change and still molds a perfect part. We believe that's the future."
When it comes to running PCR, Altonen said the industry needs to embrace variation.
"This means we need to embrace technology solutions that enable running highly variable materials, since it is unnecessarily expensive and complex to attempt to remove this variation from PCR material," Altonen said.
Imflux offers the most effective adaptive technology available to handle this variation, he added, pointing to the Auto Viscosity Adjust feature, which automatically adapts the process to the resin viscosity changes experienced with each shot.