July 1, 2008 Materials scientists and engineers added reinforcements to flexible plastic fishing lures to keep them from snapping off their hooks. Braiding microfibers into the lures with techniques used in aircraft or bicycle frame construction, adds strength to plasticized lures that contain phthalates.
Fishing is one of America's most popular pastimes. The U.S. Fish and Wildlife service says more than 28-million people will go fresh-water fishing this year, spending billions on fishing lures, lines and poles.
But there's a downside -- researchers say 12-thousand tons of those plastic lures end up in lakes and waterways every year. But now, polymer scientists and one savvy fisherman may have the solution.
Fishing lures. For competitive fishermen like Drew and Derek Frederixon are as much a part of the sport as the rod and reel. But they're hardly indestructible. Drew goes through dozens of bags of lures in a single day. And it all adds up. In fact, more than 12-thousand tons of plastic lures wind up at the bottom of lakes and waterways every year, creating environmental and health hazards.
Many lures contain a chemical recently banned from children's toys in California.
"Half of that material are plasticizers are phthalates that are slowly seeping out and defusing out of those fishing lures that are in the rivers," Tim Osswald, Ph.D., polymer scientists at the Polymer Engineering Center at the University of Wisconsin, Madison, told Ivanhoe.
Some contain chemicals so corrosive they can eat through Styrofoam in less than two days.
Fisherman and entrepreneur Ben Hobbins had an idea. He called on Dr. Osswald and his polymer research team at to help him develop a plastic bait that wouldn't break.
"The mission was to create a soft plastic lure that the fish loved to munch that would not come off," said Hobbins.
They developed a new kind of lure called ironclad. Reinforced from inside with microfibers, it can take 93 pounds of force without breaking. These fishermen say when lures stay on the hook and off the bottom of lakes and waterways, everybody wins.
WHAT IS ELASTICITY? Different materials can withstand different amounts of deformation, a property known as elasticity. Most materials are elastic to some degree: when they are deformed or bent by an infusion of incoming energy, they will bounce back to their original shape. But elastic materials all have their limits. Traditional soft plastic fishing lures have a very low threshold and will snap or tear when only slightly deformed. The new types of soft plastic lures are reinforced to be stronger by braiding microfibers into the plastic. This technique had not been used with soft material before, but is used to construct aircraft and high tech bicycle frames.
WHAT ARE PHTHALATES? Most traditional soft plastic lures are made with polyvinyl chloride (PVC). To make PVC flexible, manufacturers add a large portion of plasticizer, a type of material called phthalates, which works its way in-between chains of polymers. This allows the long chains to be spaced farther apart, enabling the plastic to obtain the gummy worm –like consistency of soft bait lures. Concerns over the possible negative impacts of phthalates on health have led California to ban including certain types of toys for kids. Other states and countries have also considered or implemented similar restrictions.
The Materials Research Society contributed to the information contained in the TV portion of this report.