Polylactic Acid (PLA) has been around for more than a decade. Formulated from corn starch in the U.S. (tapioca root in Asia and sugar cane in other parts of the world), PLA has gained some ground in the “green” packaging market. PLA was designed for and is used to thermoform food containers such as deli containers for take-out food and drinking cups.NatureWorks LLC, which began as a Cargill research project in 1989, is today the largest producer of PLA in North America. Their newest product, Ingeo, is made from wheat, sugar beets, sugar cane and corn. Their products are compostable, but only in a biodegradable organic composting facility – not out in the open in road-side ditches, which is a common misperception of PLA.Additionally, there is today a big controversy over whether diverting thousands of pounds of food into PLA food containers and drinking cups, is the best use of agricultural resources. A recent article pointed out that this diversion is playing a role in the higher cost of food in the worlds grocery markets.If you do decide to incorporate PLA into your sustainable manufacturing plan you will need to consider both the benefits and challenges.
The benefits of PLA are substantial PLA (Polylactic Acid) could be a natural replacement for many products currently made of polyester, polyolefins, polystyrene and cellulosics. The performance characteristics of PLA are consistent with these materials and PCC produces a wide variety of compounds designed to maximize its effectiveness. PLA is perfect for a broad range of packaging applications including rigid thermoformed food and beverage containers, coated papers and boards and other packaging applications. PLA biopolymers can be clear, opaque, flexible or rigid. PLA biopolymers provide a gloss and clarity similar to polystyrene, and exhibit tensile strength and modulus comparable to hydrocarbon-based thermoplastics. But PLA polymers are corn-based so they are abundant yet renewable, strong yet flexible. They don’t deplete petroleum reserves and they come from the U.S.A., reducing our dependence on foreign imports. Like polyester, PLA resists grease and oil, and offers an excellent flavor and odor barrier. PLA provides heat seal capabilities at temperatures equivalent to polyolefin sealant resins.
As the market for PLA grows, the interest in expanding the range of uses has been limited by a variety of processing challenges. Improved impact and aesthetic properties of PLA could expand its use. There are issues with the noisy nature of the polymer when used in certain packaging applications. High clarity and improved impact properties are critical in many widely used PLA applications, such as thermoformed food packaging. These issues are routinely cited as major challenges that must be addressed for PLA to expand into additional markets.