UNCC researchers create a formula for recycling old bottles into new building materials
By Amber Veverka, Special Correspondent, Charlotte Observer
A UNC Charlotte researcher with a passion for sustainability is creating a new building material out of recycled plastic bottles and an ancient grass.
Dr. Na Lu, an assistant professor at UNCC's Department of Engineering Technology, has created a material she believes may outperform composite lumber and wood lumber in many uses, and which has potential to be used in the residential and light commercial building industry.
In her lab at UNCC, Luna, as she prefers to be called, holds a dog bone-shaped sample of her creation: a beige plastic woven with threads of what looks like horsehair. "Hemp," Luna says, and points to a fluffy pile of the fibers on the table.
Unlike much present-day composite lumber, Luna's product substitutes hemp fibers for more typical chipped wood often mixed with virgin plastic. And unlike pressure-treated wood, the hemp material contains no toxic heavy metals.
Wood fiber is structured like a bundle of straws, she said, but hemp's crystalline structure gives it greater mechanical strength. She demonstrates by holding out a handful of hemp fibers to pull.
"This (hemp composite) material performs up to 4,000 to 6,000 psi (pounds per square inch)," Luna said. "That's as strong as medium-strength concrete."