Yes! We have achieved deterioration! This is week three of my unofficial, unscientific test of 100% compostable packaging claims from SunChips and Boulder Canyon. Three weeks ago, I buried the bags in my home compost pile, along with a Doritos bag just for fun, and I have been digging them up to see how they are doing.
Although it’s mid-October, the weather has been holding nicely. It’s been averaging in the 60s, with a combination of sun and rain, so while I don’t actively turn the pile, it’s got lots of raw materials to work with.
This week, only three weeks into the experiment, I am seeing real deterioration of the Boulder Canyon bag.
I have been unsuccessful in finding out the substrate used for the SunChips bag. My assumption was corn, and after additional poking at SunChips, I have gotten confirmation only that the substrate is “vegetable-based.” The Boulder Canyon bag, on the other hand, is made from tree-fiber. The top layer of the packaging is already deteriorating, with large chunks already deteriorated or pulled away. By contrast, the SunChips bag looks no different from the non-compostable Doritos bag sitting next to it.
My assumption is that SunChips went for corn-based packaging rather than tree fiber for shelf life. Although tree-fiber-based bags can be made with various compostable liners, the issue is the longevity of the performance characteristics they exhibit. SunChips, as a larger company with larger volumes, is going to require more longevity than a smaller, regional company and therefore may not be able to “get away with” using fiber-based substrates.
Once I get an answer to that question, I’ll let you know. See y’all next week. Now that deterioration has started, it’s going to get more fun!
Heidi – thanks for your continued interest in the SunChips bags. The 100% compostable SunChips bags are made from plant-based materials and are designed to fully decompose in 14 weeks when placed in a hot active compost bin.
The three layers that comprise the bag packaging (outer print film, inner barrier film and adhesive layer) are all made with the plant-based polylactic acid (PLA) provided by NatureWorks LLCI and is trademarked under the Ingeo name.
To set up the optimal hot active compost bin, check out the video on our site at http://www.sunchips.com.