Polymer Profile: Brennan Wodrig, Technical Service Engineer | Blown Film
Meet Brennan Wodrig, a Technical Service Engineer and polymer expert specializing in film extrusion. Brennan is conducting a series of trials around PPAs to help keep converters informed.
Brennan Wodrig
Technical Service Engineer | Film Extrusion
With the opening of its new polyethylene plant in Monaca, USA, Shell Polymers has been hiring a team of industry experts, aka Polymer Pioneers and Polymer Pros, who have a proven track record in polyethylene. Technical Service Engineer Brennan Wodrig has over a decade of experience in polymer processing, and he’s putting it to good use with his trials examining how PFAS-free PPAs stack up compared to traditional PPAs during film extrusion.
How Technical Service Engineers Conduct Research
Shell Polymer’s team is always interested in analyzing how new developments and innovations impact converters–and when there isn’t existing research to draw on, that means doing it ourselves. That’s why Brennan set out to help blown film converters looking to remove polyfluoroalkyl substances and perfluoroalkyl substances (PFAS) from their polymer processing aids (PPAs) with some answers.
“The goal of our trial was to compare the efficacy of PFAS-free PPAs with an industry standard fluoropolymer,” Brennan explained. “We started off with a barefoot material as a control, calculating that as our 100% melt fracture and zero-minute timestamp. From then on, we would introduce the PPA into the extrusion system, and with that, we measured various criteria.”
In addition to testing out PPAs on their own, Brennan conducted additional experiments using mixes of PPAs. “We haven’t found one single PPA out there that can suit everyone’s needs,” Brennan said. “So what’s going to happen to your process if you go from one PPA to another?”
Brennan ran these trials at Shell Polymers’ Applications Hall, which is open for converter use for experiments, demonstrations, and trial runs. “The equipment we used for this is an industrial-sized blown film line from Alpine. It’s a new piece of equipment.”
Brennan Wodrig“Performance isn’t the only consideration to look for when you’re looking at different PPAs. You need to consider cost, compatibility, loading, and printability.”
Brennan’s Top Four PPA Takeaways
PPAs have significant benefits.
Even before considering PFAS-free vs traditional PPAs, Brennan’s trials made clear that PPAs have significant benefits for film extrusion. Brennan explained that “Since the 1960s, PPAs have been perfected to reduce motor load, and they minimize or eliminate melt fracture at higher outputs.” Additionally, PPAs reduce die lip build-up and lower extrusion melt pressure.
Next-generation PPAs had mixed standalone performance.
For converters looking to eliminate PFAS from their PPAs, the head-to-head results from Brennan’s trial comparing next-generation PPAs to their traditional counterparts offered encouraging data, with a few areas of caution. “Most of these PPAs did decrease motor load, did decrease melt temperature, and did clear melt fracture. For some select PPAs, we had an increase in extruder output and a large deviation in melt temperature.”
Not all PPAs work well together.
After testing 50:50 mixes of different PPAs, it’s clear to Brennan that combining next-generation and traditional PPAs has to be done thoughtfully. “Both of the siloxane-based PPAs we tested were antagonistic, which means they took more time to clear together than when they were tested separately,” he explained. “For the non-siloxane-based PPAs, we found one combination was synergistic and another that was compatible.”
More testing is required for next-generation PPAs, but initial results are promising.
Brennan is interested in continued research and testing on next-generation PPAs, but based on his initial findings, there’s reason to be optimistic about the space–with a few caveats. “Most of the next-generation PPAs cleared melt fracture faster than a traditional PPA, and it took less time to purge them from the extrusion system. Some possible limitations with these PPAs include extruder output, melt temperature and pressure deviations, extruder stability, and surface build-up.”
An Unrivaled Customer Experience
At Shell Polymers, we want our customers to be the center of everything we do. To demonstrate this, our business has created a space unlike any other in the industry that will hold multiple pieces of new, industrial-sized machinery across five different markets and processes. We understand the challenges associated with shutting down a production line for a trial, so we want our customers to have the luxury of utilizing this space and equipment to avoid downtime.
For example, suppose a customer wants to test new multi-layer film designs but can’t afford downtime on their own coextrusion line. In that case, we are happy to provide testing using cutting-edge equipment in the Applications Hall.