"Fly ash" is pretty much what it sounds like: fine airborne particles of ash. It's generated in large quantities during the manufacture of paper and cardboard, along with a lot of sludge. Although a certain amount of that waste can be used as aggregate in concrete, most of it just ends up being dumped in landfills. That could be about to change, however, as Finnish scientists have discovered that it can also be used as a raw material in plastic goods.

As part of the European Union's Reffibre project, researchers at the VTT Technical Research Centre of Finland performed lab tests which indicated that the ash and sludge could replace up to 50 percent of polypropylene in injection-molded or extruded plastic composites.

Not only would this keep the paper waste products out of the landfill, but it could also bring down the production costs of the plastic items, plus it would reduce the amount of petroleum-based polypropylene required.

Additionally, by tweaking the ratio of ash/sludge to polypropylene, it's possible to tweak plastic characteristics such as strength, stiffness, heat resistance, appearance and surface texture.

So far, the VTT team has created plastic floor tiles and storage containers which are composed of 30 percent paper waste. Down the road, the process may also be used for items like crates and pallets.