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The Oakwood Group's engineered polypropylene energy absorbers can be attached to a headliner via hot melt adhesive or an infrared energy joining process. Approximately 70% of Oakwood's energy absorbers for the automotive industry are for headliners. (For more images, click on the grey bar at the upper right corner of this image.)

Thermoplastic technology offers impact protection across automotive, sports, and defense

The Oakwood Group and its technology licensee companies are designing engineered thermoplastic solutions to help protect vehicle occupants, sports players, and soldiers from severe impact injuries.

“We’re big believers in being solution providers,” Joel Cormier, Director of Development Engineering for The Oakwood Group, told Automotive Engineering during an interview at the firm’s Taylor, MI, manufacturing center.

With 18 issued patents and several pending patents, The Oakwood Group’s engineered material safety solutions account for a hefty chunk of the privately held company’s $75 million in annual sales. The supplier claims a market-leading share for its polypropylene head impact energy absorbers used for headliner applications, and its technology licensee companies, Viconic Sporting LLC and Viconic Defense LLC, are making application inroads with the infinitely tunable plastic energy absorbers.

Matthew Gerwolls, Oakwood’s Director of Sales and Marketing, said the $250,000 that Viconic Sporting won from the National Football League, Under Armour, GE-sponsored Head Health Challenge II innovation contest in 2014 is game-changing.

“The grant money will be used to continue product development for an artificial turf surface underlayment designed to make the playing field safer for the players. It’s the same core technology that we use for vehicle applications,” Gerwolls explained to Automotive Engineering.

Oakwood began producing plastic-engineered energy absorbers for headliners in 2000, adding side impact energy absorbers for door panels four years later. Steering column energy absorbers will join the application lineup as early as 2016.

“The key difference from our automotive safety product is the turf underlayment is designed to work for multiple impacts,” said Gerwolls, a mechanical engineer with a master’s degree in engineering management from Wayne State University in Detroit.

In the turf underlayment prototype, the less than 1-in (25-mm) tall thermoplastic polyurethane cones are designed to recover their shape again and again after repeated impacts. “In an automotive application, the task of absorbing energy in a crash is only done once,” Gerwolls said. “But it’s possible a recoverable energy absorber could be used on future vehicles, such as a pedestrian safety application.”

Depending on the specific application, plastic cones are engineered to precise heights, draft angles, wall thicknesses, and matrix spacing. Said Cormier, “Because of that, it’s possible to cross-pollinate between industries.”

Another technology transfer example is Viconic Defense’s blast floor mats. The mats are designed to help improve injury outcomes, especially to the heel and tibia, resulting from an improvised explosive device (IED) hitting U.S. Army tactical vehicles. These blast floor mats are inspiring energy-absorbing undersurfaces for other industries.

“We are looking at flooring applications, whether that’s for a vehicle or something else, like the floors in a nursing home. It is possible that an energy-absorbing product could help prevent a hip break or other injury if grandma or grandpa were to fall down on a hard flooring surface,” said Cormier.

Oakwood’s product development wheel is expected to spin out a next-generation technology later in 2015 via an NVH solution that adds “silence domes” to the grid of plastic energy-absorbing cones used for headliner applications.

“This isn’t the first change to our energy absorbers. Over the years we’ve been integrating other features and functions, like ribbing for localized stiffness and retention hooks for wiring harnesses,” Cormier said. “We spend millions of dollars every year on research and development to get that next product that will carry the company forward for another 20 to 40 years.”

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