Cargill Polymer Processing Aid Offers an Alternative to Fluoropolymers

In 2020, the agribusiness and industrial supplier Cargill repeatedly heard the same question from plastic film producers: What can we do without fluoropolymers? Five years later, at K 2025, Cargill presented its answer, the Incroflo P50 processing aid. 

During polyethylene extrusion, the difference between the slow-moving flow adjacent to the steel wall and the faster moving flow in the center increases with increasing speed. “What happens is the material at the die interface suddenly slips — but it doesn’t keep slipping. It stops. It slips again, and stops,” says Adam Maltby, research and technology fellow at Cargill. “You get a stick-slip motion and that causes this shark scale pattern on the surface.” Fluoropolymer processing aids added to the polymer clear this effect. Fluoropolymer acts as a flow promoter because it’s omniphobic and tends not to stick to either the metal of the die surface or the polymer. The result is slip-flow condition. Fluoropolymer processing aids also prevent the build up of material on the die. 

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Problems with PFAS

But concerns about the release of PFAS (per- and polyfluoroalkyl substances) and their effects on the environment and public health have placed the future of fluoropolymer processing aids in doubt. In the EU, proposed revisions to REACH (registration, evaluation, authorization and restriction of chemicals) restrict the use of PFAS materials of all types, including polymers along with other, more bioavailable types such as perfluoroalkyl carboxylic acids. A proposed “time-limited derogation” would allow 6.5 years for transitioning away from PFAS in film extrusion.

In the US, individual state legislatures have restricted PFAS: their approaches vary widely. Processors looking to get ahead are seeking alternatives, and several companies are supplying them — a group that now includes Cargill.   

Cargill’s Incroflo processing aid. Source: Cargill

Knowing they were unlikely to find any solution with the unique properties of fluoropolymers, Maltby and the research group at Cargill experimented with various chemistries. “We started with probably half a dozen chemistries, polymeric materials,” says Maltby. Trials included polyethylene glycols, but compatibility was an issue.

Another material borrowed from a separate project showed promise. The team took that polymer structure, simplified it, and found that it was working to eliminate sharkskin. “We then took that chemistry, complicated it, and varied all the components,” says Maltby. In successive trials they found formulations that removed sharkskin but ruined the output rate. So they focused on the chemistry to optimize both. Knowing that customers would want to target food applications, Maltby and his group found monomers that were already food approved to build their product.

At K 2025 Cargill exhibited LLDPE processed with (right) and without (left) Incroflo. Source: Matt Stonecash

Maltby says the Incroflo P50 is 86% bio-based but could be 100%. At present, the availability of one of the monomers from bio sources is limited, so going 100% bio-based would increase the cost dramatically. But that could change in the future. 

“One of the reasons we’re doing this is that we have access to bio-based monomers that we are already using, that we can access as an existing toolkit, if you like,” Tom Dutton, industry manager for polyolefins at Cargill, tells PT. 

Incroflo P50 is now available commercially, though Cargill plans to continue development, including exploring co-additives to boost performance. The product is polymer only at present, so customers can combine with additives without the concern of interference. 

“There’s a lot of good people working on this,” says Maltby.  “It may be that if you take technology A and technology B and put them together, you’ll get more than you thought.” Cargill has focused on LLDPE, but there are possible applications in HDPE and PP as well. 

“For me, as a scientist, to be involved in something that started in 2020 as an offhand comment at the end of a meeting, to start to work on it, see some effect with a new material, transfer that to the plant, scale it up and commercialize it ... to actually take something from the ground up, I would say it’s the most interesting thing I’ve done,” Maltby notes.