PLA, or polylactic acid, is a compostable non-toxic plant plastic used in food packaging, toys, layered packaging, and 3D printing filament. Possibly the most well-known of bioplastics, PLA was first discovered in the 1920s. In 1989 U.S. chemical giant Cargill tackled the process of commercializing its production into polymers that could function as a replacement for single use petroleum plastics.
PLA is made by fermenting plant sugars from corn, sugar beets, and cane. PLA’s virtues are substantive: derived from plants instead of fracked gas, non-toxic, and relatively shelf-stable, PLA can be processed on the same equipment as petroleum plastic with testing and modifications.
PLA is fully compostable in commercial composting settings, however it can take a very long time to start to biodegrade in the general environment. Makers of early PLA product entered an unregulated market with sometimes hyperbolic marketing claims about its compostability and suffered a backlash of public sentiment.
Today, PLA is often blended with other raw inputs to enhance the mechanical properties of the final materials, and can be sourced globally. PLA coatings provide temporary water and oil resistance to bamboo and tree papers, while allowing the resulting package to remain fully compostable. PLA burns and melts cleanly, and so in recent years has become the filament of preference for the growing 3D prototyping market.
PLA product is also currently being reclaimed and recycled by a number of startups, and Ingeo is developing a process by which plant sugars are bypassed completely to produce PLA directly from greenhouse gases.