Hankook upending tire design paradigms with i-Flex airless tire

NASHVILLE, Tenn.— For Hankook Tire & Technology Co. Ltd., the nonpneumatic tire development space is one of those places where innovation and investments offer returns in the form of insights.

"It is always difficult to introduce new concepts that completely change existing perspectives," Ted Choi, Hankook Tire America Corp.'s vice president of marketing strategy told Tire Business sister publication Rubber News recently.

"However, we learned a lot in the process of making the initial idea a reality, which greatly improved Hankook Tire's technical capabilities. This process has reminded us of the importance of constant innovation and improvement."

Hankook's journey into the NPT space began roughly 13 years ago, when engineers started exploring the idea of using alternative materials to support the load on the tire and saw potential.

Lots of potential.

"We wanted to seek out technological advancement through the change of the tire paradigm," Choi said. "By removing compressed air, which is the basis of the performance of existing pneumatic tires, it was determined that access to a different performance area from pneumatic tires would be possible.

"NPTs open up new design and functional possibilities. No air space is required, allowing you to design the shape and structure of the tires more freely, which can open a new era in vehicle design."

Nnon-pneumatic designs offer the potential for enhanced safety as NPTs don't face failures from air loss, a n i operating parameter that opens possibilities for designing for tire performance because maintenance issues are less likely to impact key performance traits such as contact footprints.

Besides broader design parameters, Hankook engineers also saw opportunities in emerging vehicle technologies, such as autonomous operating technology, and changes in vehicle ownership behavior that would favor greater fleet applications, where downtime matters.

To that end Hankook moved forward with technologies that could make a difference with reduced maintenance time and costs.

That has led the company to the i-Flex, its first working prototpye.

"The i-Flex seems likely to be used in small vehicles, electric vehicles and self-driving vehicles such as robo-taxis, which are heavily driven in the city center," Choi said. "In these vehicles, the durability of airless tires and the reduction in maintenance requirements will be a major advantage."

And while i-Flex — which met the public at expos across the globe, including the 2022 Consumer Electronics Show in Las Vegas — may be the most talked about of Hankook's NPT concepts, the technology isn't reserved for the passenger vehicle space.

Hankook intends to develop NPT solutions for every sector that needs it.

"We are also looking at commercial vehicles and long-distance trucking," Choi said. "Even in these areas, the introduction of airless tires will reduce costs and increase efficiency, which in the long run will bring positive changes to the industry as a whole."

When it comes to those positive changes, Hankook sees NPT playing a critical role in moving the company — and the industry — closer to sustainability and circularity.

Because NPTs are much less likely to fail prematurely, they are also likely to last longer — particularly if the materials that make up their supporting structures are durable, keeping more end-of-life tires out of landfills.

That thinking has led Hankook to take retreading into consideration when designing its NPTs.

"Yes," Choi said, "i-Flex is developing manufacturing technology for retreads in parallel. To this end, we are studying tire casing (wheel and spoke) materials with improved heat and fatigue durability."

Any tire maker operating in the still-not-quite-conquered modern nonpneumatic tire space will tell you that's an aim easier stated than actually achieved.

In fact, there are a lot of challenges that come with NPT development. Ironically, the very essence of nonpneumatic technology is its challenge.

"The biggest challenge in developing NPTs is finding a structural design and optimized materials to achieve the ultimate performance of tires," Choi said.

"This is because these factors have a decisive impact on the durability, safety and performance of the tires. Material scientific challenges are critical in tire performance and are optimized in conjunction with structural deformation mechanisms."

The tire maker noted that its material science expertise gives it the flexibility to apply advanced materials technology that breathe life into its airless tire concept.

And that breathes life into other products.

Designing and optimizing its airless tire concepts has strengthened Hankook's innovation and development in ways that may be unexpected. By breaking down that air-filled-tire paradigm Hankook gained critical, new perspectives applicable to its pneumatic products.

"These technological advances help improve the performance, durability and safety of pneumatic tires," Choi said. "The development of NPTs allows us to explore the possibilities of tires with a broader perspective, (and) this makes us think about the new values and capabilities that tires can provide to vehicles and drivers beyond traditional pneumatic tire designs."

That's because Hankook looks at the big idea of airless tire design and sees something more — creativity, possibility and insights.

So when you look back on the tire maker's nonpneumatic tire development journey — from i-Flex to the future — don't lose sight of the fact that NPT is a relatively new and critical component to achieving a bigger goal.

"Hankook Tire's development of nonpneumatic tires is part of our innovative approach and constant research and development. Our efforts and enthusiasm in this area play an important role in keeping us at the forefront of the industry," Choi said.

"And finally, Hankook Tire's development of nonpneumatic tires means more than just making new products. This shows that we are working to create a sustainable future for the tire industry. This direction is a key part of our business model and corporate culture, which makes us proud."