MaterialsGuru

The June 2007 issue of Plastics Engineering provides several interesting facts about the demand, usage and production of bioplastics in the cover story. Quoting a Freedonia Group report (Degradable Plastics, September 2006), it estimates that the demand for biodegradable and compostable plastics in the U.S. is expected to increase 20% per year through 2010. Led by polylactic acid (PLA) and starch-based bioplastics, the total volume by 2010 is estimated to be around 420 million pounds. Packaging industry presents the best opportunity for these materials in applications such as films, bottles and food service products.

Contrast that to the following growth projections for some of the major plastics film markets (see Freedonia Report Plastic Film, August 2006):

• Low density polyethylene film used in produce and snack packaging, shrink wraps and trash bags: 2.8% per year growth to 9.7 billion lbs by 2010
• Polypropylene film used in produce, grain mill and dairy products packaging: 3.4% per year to 1.5 billion lbs by 2010

Certainly, market growth rates for bioplastic film packaging are significantly higher than those for the conventional plastics, although the total market is still quite small. In order to compete with low density polyethylene and polypropylene, PLA and starch-based bioplastics will need to be cost-effective on both resin and film processing costs. Although, petroleum-based plastics have recently seen various price increases/volatility and supply interruptions, cost of corn-derived bioplastic such as PLA is still sky-high in comparison. According to one estimate, currently PLA is at an average of $1.3/lb, which is expected to fall below $1/lb within a year as more capacity becomes available. Still, there is considerable risk to PLA cost due to volatility in corn and energy prices. Starch-based bioplastics are likely to be less expensive; however they too are not immune to rising energy prices. Therefore, resin cost is likely to remain a key barrier for growth of these bioplastics.

Despite the cost challenge, several interesting examples of packaging applications are emerging. A few are listed below:

• Biophan(R) crystal-clear PLA film from Treofan GmbH for food packaging
• BIOTA (Blame It On The Altitude) water bottles (Naturworks PLA)
• NaturallyIowa Milk bottles (Natureworks PLA)
• PLA bottles in the German drugstore IhrPlatz (drinking water)
• Earthfirst(R) PLA film for various applications
• Clear oxide barrier coating on PLA film for oxygen-sensitive packaging