PSG boasts sustainability, efficiency with SureMix additive

KNOXVILLE, Tenn.—While Polymer Solutions Group's SureMix additive has been around for several years, it's coming to the forefront amidst the transition to an EV era and increased focus on sustainability.

And with this transition, demand for the additive is sure to increase.

"One thing with (electric) vehicles is they're very heavy," Aaron Puhala, vice president of innovation at PSG told Rubber News during the International Elastomer Conference. And this means EVs are very "torquey."

"There's a lot of weight and a lot of torque, so there's a tendency to need more traction (in tires)," he said.

To get this increased traction, tire makers must add more silica to their mixes.

"But they also want to maintain a fuel economy. So, they need things like SureMix to allow (the compound) to be processed and to bring the fuel economy."

From the point of development, SureMix has been around for about seven years, Puhala said, noting PSG's customers include "all of the top 20 tire companies, and then beyond that."

But the "genesis" of the additive, he said, was the common need across the tire industry for improvements in both processability and properties in silica-based compounds, "specifically for tread and for fuel economy."

"They're all trying to get more silica in, but if they put more silica in, it gets more difficult to process, and it gets more difficult to get the fuel economy," Puhala said.

The additive works for both carbon black- and silica-based compounds, coming in two grades: SureMix S6, for both carbon black and silica, and SureMix CO², which targets primarily silica.

Puhala said the best way to think of SureMix is less as an additive and more as an enabler.

"If you had a silica compound that has 80 parts of silica … and you want to improve the wet traction of that compound, the best way to improve the wet traction of that 80-parts silica compound is to put in more silica," he said as an example.

If a mixer goes from 80 parts of silica in a mix to 100 parts, they'll see a "dramatic improvement" in the wet traction.

"The problem is, your factories, if you try to tell them, 'Hey, put 20 more parts of silica in that compound,' they're going run you out of town."

With more silica in the mix, the processability of the compound becomes more of a challenge, he said, noting this typically would increase the number of mix passes.

"You may have a compound that's already going through the mixer three times with 80 parts of silica. If you try to add 20 more parts, it's going to have to go through the mixer at least one more time. And depending on how old your mixer is, you may have to go through even another time."

Which doesn't bode well for cost of production, energy consumption or efficiency.

"You have plants that are capacity constrained, and it's an expense. Every mix batch you add is an expense," Puhala said. "So, what we show is that if you use SureMix CO², you can get that extra 20 parts of silica in and actually get to a viscosity that's lower than what you started with.

"What you end up having is: you've increased the wet traction dramatically, you really haven't impacted your capacity at your plant because you're able to mix it and process it, and you've got the fuel economy of the 100-part compound," he added.

And it's all done through what's called hydrophobation.

"When you put silica into rubber, it's kind of like trying to mix oil into rubber. It doesn't want to be mixed in."

What SureMix does, he said, is it hyrophobates the silica, making its surface more like the rubber into which it is mixed.

"When you hydrophobate, you bring what's called the hysteresis down, which improves the fuel economy."

With SureMix, he said, PSG brings cost savings and efficiency to the mixing industry, which also results in improved and more sustainable products in the tire industry.

"SureMix products are sustainable in themselves in terms of their chemistry," Puhala said, noting the additive's composition is 100-percent biocarbon. But they're also sustainable in what they do for the rubber industry.

By improving the processability of silica-based compounds and increasing wet traction of tires, the additive brings higher efficiency and improved fuel economy to the mixing and tire industries.

"As the enabler, we're not only allowing our customers to use less energy—or decrease the amount of additional energy they need to use—the tire in use uses less energy."

Five-pass mixes without SureMix produce up to 2,600 metric tons of CO2, according to PSG's website. By adding SureMix, the number of passes can be reduced, eliminating up to 450 metric tons of CO2 production.

Likewise, the company also boasts energy reductions of up to 1,000 MWh per year due to fewer mix passes with SureMix.

PSG is headquartered in Cleveland, Ohio, where two plants and a technical center are located. The company also has two plants in Albany, Ga., and another technical center in Macon, Ga.

Puhala said PSG develops its SureMix across all these locations.

The additive is currently compatible with natural rubber, SBR, SSBR, FSSBR, BR, EPDM, NBR, HNBR and CPE.

But PSG is working to develop next generations of SureMix, as well as products beyond it.

"We have other things we're focusing on for carbon black even more specifically, … and we're working on next versions of SureMix," he said.

And as the company further develops this product, Puhala noted that it's critical for the company to work closely with its customers, or to break the ice with new customers.

"The leading tire companies are using silica everywhere, but you'd be surprised how many are just coming along with silica, and we're very cognizant of that.

"We find the most success when we work very closely with our customers," he said. "You're going to be seeing a lot from us with respect to sustainability and from SureMix."