Like many petroleum-derived plastics, closed-cell extruded polystyrene foam—known commonly by the brand name Styrofoam—poses a waste problem. Although the material can be recycled, it is more often discarded. And as a result, current recycling streams aren't designed to take full advantage of the material’s potential second life.
In Mexico, where approximately 60,000 tons of the material are produced annually and its recycling channels are underdeveloped, startup Rennueva is developing a novel way to convert the waste material into a usable substance. Its Reps-01 prototype machine transforms the air-entrained product, which is made up of 5 percent polystyrene and 95 percent air, into hard plastic pellets. The tiny beads can be used to create new polystyrene products and they occupy much less volume than the original material.
"The [closed-cell extruded polystyrene foam] has a very high potential for recycling, but the problem is the lack of formal gathering practices, as well as the lack of Mexican technology for this purpose," Rennueva founder Hector Ortiz told Investigación y Desarrollo, adding that Rennueva is partnering with the Mexican subsidiary of Road Mason, Mich.–based Dart Container to develop and commercialize the new technology.
The machine converts the material through the process of thermodensification, through which it is crushed, compressed, and melted, before it is cooled and cut into pellets. According to Ortiz, Rennueva's technology can transform approximately 220 pounds of the closed-cell extruded polystyrene foam into 213 pounds of small plastic beads in one hour.
Although safe and VOC-free polystyrene extraction methods have been developed, it's not yet clear whether Rennueva's version poses human-health concerns related to off-gassing. Such potential challenges aside, the technology represents a promising method of converting waste into usable feed-stock for new products.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.