Biopolymers are springing up throughout the packaging landscape like wildflowers, adding fresh touches of “green” to markets sensitized to sustainability.

             Among the applications for foods, biofilm bags seem to be a highly popular variety this year.

Packaging Strategies last issue reported on Snyder’s pretzels, which made the move into snacks packed in bags made of Ingeo polylactic acid (PLA) from NatureWorks LLC.

Snyder’s is following along the lines of Frito-Lay’s SunChips conversion from a 33% PLA structure last year to a 100% compostable PLA structure in 2010.

          But not all bio-film bag structures rely on PLA. Consider Boulder Canyon, which claims to be using the first compostable packaging for natural snack food. Instead of PLA, the 7.5-ounce bags are made from wood pulp sourced from plantations that have Forestry Stewardship Council (FSC) or similar certification.

          The packaging uses materials certified to meet the "Specification for Compostable Plastics" standards set by the American Society for Testing and Materials (ASTM). The bags can be composted in home or industrial composters, recycled through approved organic recycling programs, or incinerated at modern incineration plants.

          The company says the wood pulp sourcing avoids the potential negative impact on existing food supplies of biopolymers made from corn or other starches such as PLA.

The new packaging is available immediately at Colorado-area Whole Foods stores with a suggested retail price of $3.49 to $3.99.

          A fresh new segment for this kind of sustainable bag structure springs up with Stahlbush Island Farms, , , which launched a first-of-its-kind biodegradable bag – the BioBag ---- for the company’s frozen fruit and vegetable lines. Supplied in rolls by Cadillac Products Packaging Co. for form-fill-seal application, the bags rely on brown kraft paper and water-based inks. The material’s 3- to 3 ½-mil structure comprises seven-color flexo-printed kraft paper laminated to a polymeric sealant with a special additive that makes it also degrade, according to Chris Mitchell, Cadillac’s business manager.

          Cadillac reports that the key challenge was to create a biodegradable bag that maintains a normal shelf life across products. Mitchell says the company is experiencing 20% growth in sustainable-related packaging materials compared to 5% to 10% growth for that of conventional materials.

          On yet another flexible front, calcium carbonate -- a common, naturally occurring material found in limestone used recently in bowls for General Mills’ Betty Crocker Warm Delights -- is being applied to kraft-paper-based substrates applicable for bags, sacks, and pouches by Smart Planet Technologies, a supplier of sustainable packaging materials.