CLEMSON In a well-lit testing facility several football fields away from the monumental stadium known as Death Valley, a team of researchers is searching for a material that might one day make football a safer sport.
The first phase of trials, which concluded this month, did not involve any pigskin, polycarbonate or padding.
Instead, it brought together a special hammer-like machine, an advanced spotlight and video camera and 25 different tiles made of high-strength hybrid yarns, one of which might prove ideal for replacing polycarbonate as the material of choice for use in football helmets.
The research comes at a key time, as new research about the cumulative health effects of helmet collisions is casting a growing question mark over the long-term future of a sport still by many measures is still peaking in popularity.
Dr. Elizabeth Cates is vice president for research and development at Innegra Technologies, a Greenville-based maker of high-performance fibers.
The project began when she and her colleagues saw a test dummy exhibit that Clemson made for the Roper Mountain Science Center.
“It allowed students to subject the dummy to impacts so they could measure the force of the impacts,” she said. “Some of the composite applications that our Innegra fibers go into have shown increased impact resistance, so we wondered if it could do anything in helmets?”
The start of tests
Innegra reached out to Clemson and soon teamed up with graduate student Natalie Patzin, Clemson packaging instructor Gregory Batt and Assistant Bioengineering Professor John DesJardins. They conceived of a three-step series of tests that will analyze different combinations of Innegra s fibers and measure them for their impact resistance.
DesJardins said much of the current helmet research involves altering its shape and padding but these tests will gauge whether the helmet material itself can promote safety.
“You want to have energy absorption by the material,” DesJardins said. “If not, the head is the thing that bounces.”
“The material that’s used for the shell of the helmet hasn’t changed in over 20 years,” Cates added. “We look at this as a real opportunity. It’s pretty well understood that fiber-reinforced composite material allows you to disperse the energy of the impact.”
Innegra’s 25 tiles made in conjunction with B&W Fiberglass out of Shelby, North Carolina have different combinations of different fibers, including glass and carbon and Innegra’s fibers, which are less stiff.
“Glass and carbon are both very brittle,” Cates said. “When you break them, it’s a fracture. Innegra really toughens them up and acts kind of like a safety layer, sort of like the plastic film on safety glass does.”
In recent months, Patzin has filmed a series of impact strikes on Innegra s different tiles with a high-speed camera, and then she has painstakingly replayed the film frame-by-frame to measure how much the material absorbed the impact. Both the extent of the deflection and its duration tell part of the story.
“It’s pretty labor intensive,” Batt said.
The next step
While the testing wrapped up last week, it is too soon to tell whether any of the 25 combinations show promise.
Patzin soon will begin the next step of tests, which will involve impacts more similar to those a football player might incur. Based on those results, there could be final phase of tests with molded helmets next year. Clemson already is ordering a dummy’s head form, complete with sensors like those used for automobile crash tests.
While the experiments are being designed with football helmets in mind, the results could show whether the fibers are suitable for other uses. Some already have been successfully used in things like kayak shells, snowboards and hockey sticks.
Cates described the current stage of research as very very preliminary, and she said other companies eventually could get involved.
“We’re not going to divine the best football helmet,” she said. “Our hope is that we come out of this with some compelling evidence that suggests one type of structure or another could provide more benefit over the conventional polycarbonate shell.
“And that will open the door with some of the equipment manufacturers about how we can use this information and work with them to design a better product.”
And the energy-absorption tests themselves are just one consideration of a material”s suitability for helmets.
Other factors include the material’s cost, durability, weight, moldability and appearance.
This article was republished with permission from the author, Mr. Robert Behre. The original article was published in the Post and Courier.