Polylactic Acid or PLA is a biopolymer derived from renewable resources such as corn and cane sugar. The method of developing PLA has been known for many years, but commercial interest in PLA has grown significantly over the past few years due to the ability of the polymer to biodegrade in a commercial composting facility.
Corn is harvested from the field and is broken down into its various components. The corn sugar, dextrose, is then removed. Dextrose is fermented, distilled, and transformed into lactic acid and lactic acid is then converted into PLA.
PLA is typically formed into pellets. PLA pellets are purchased by manufacturers and used in molds to create a variety of products and packaging, including: food packaging (e.g., corn cups
), textiles, furnishings, medical devices, and more.
PLA Plastic's Physical Properties
PLA plastic (often referred to as "corn plastic") has physical properties that are very similar to traditional petroleum
based plastics like PETE.
Natureworks and Other Manufacturers
Natureworks LLC is a wholly owned subsidiary of the Cargill company, is the leading manufacturer of PLA. Natureworks produces PLA under the brand name Ingeo, with a production capacity of 300 million pounds per year. PLA is also manufactured by Purac Biomaterials and a variety of other Chinese manufacturers.
PLA may be certified compostable under the standards ASTM D-6400 and EN13432 for compostable plastics. These certifications confirm that a product or packaging made from PLA will 1) biodegrade by 60-90% within 180 days of entering a commercial composting environment, 2) disintegrate by 90% into pieces no greater than 2 millimeters in size, and 3) will leave no heavy metals or other eco-toxicity into the compost beyond comparable levels in a control group.