Turning Plastic Trash into Treasure

08/03/2007
By Used with permission from the Nashua Telegraph Online By ALASDAIR STEWART

Next time you find yourself sipping soda from a plastic bottle in Bridgetown, Barbados, raise a toast to the plastics engineering department at University of Massachusetts Lowell.

While you’re at it, take a close look at the roofs of nearby buildings, and be sure to toss your empty bottle in a recycling bin.

This seemingly strange behavior won’t come as a surprise to a savvy host on the island, because a local company, Duraplast, manufactures roof shingles from recycled plastic and the process was developed in close cooperation with UMass Lowell researchers, including Professor Robert Malloy of Londonderry.

The shingles, which are lightweight and hold up well under the tropical sun, do much more than cover homes. The Duraplast plant in Newton, in Christ Church Parish, became the island’s first plastics compounding and injection molding facility when it opened in 2001.

On an island about 2½ times the size of Washington, D.C., with a population over a quarter-million and many visitors, keeping plastic bottles out of landfills is a big benefit, too.

Pretty neat, but shingles are just a drop in the bucket of innovations UMass Lowell researchers have come up with over the years to turn junk plastic into good stuff.

Other products include toothbrushes, light-blocking milk jugs ߝ which help preserve milk’s nutritional value ߝ construction materials and yam sticks.

The yam sticks are particularly interesting from a conservation standpoint, because farmers in numerous countries use large tapered sticks to encourage creeping plants to grow, increasing their foliage and the quality of crop.

Ordinarily, yam sticks are made by cutting and stripping saplings by the millions, which contributes, of course, to deforestation. A technique developed at UMass Lowell makes manufacturing yam sticks out of plastic bottles and the like fairly simple, especially helpful on islands where space, forests and resources are limited.

While the plastics engineering department has had its hands in the plastic-lumber scene for some time, other construction materials are quite new. The materials, which have yet to be widely commercialized, combine used plastic with high-carbon ash that is a waste product of coal-fired power plants. There’s plenty of ash to spare ߝ only about a quarter of the nearly 50 million tons produced nationwide each year gets used.

By mixing ash and plastic, researchers have made “synthetic lightweight aggregate,” industrial-ese for fine gravel.

The aggregate could be used for a variety of construction purposes, such as fill around foundations, or could be formed into strong, lightweight cinder blocks.

Although there is no shortage of gravel, recycling ash and plastic would reduce the need for mining, which is not always the most popular of industries, as well as giving waste ash and plastic a home.