Can you see the bag? Look for the blue spots
Today marks the first week of my SunChips compostable bag experiment. These updates will be brief without any fluff and stuff. My format will be more scientific and less opinionated!
I. Title: The SunChips Compostable Bag Experiment.
II. Purpose: To test the compostability of the SunChips bag. Will it compost in a worm bin in 13 weeks, using the correct amount of browns and greens?
III. Prediction: I believe the bag will break down into usable compost in 21 weeks. (I loved when I was 21! Oh, that summer at college was amazing!). I just picked that number out of my as%, just knowing it will be longer than 13 because SunChips recommends the hot composting method over the cold vermicomposting method. 21 just sounds like a good # and the movie wasn’t too bad either! The book was better!
IV. Materials: Wonder Worman Bin, about 2lbs of Red Wigglers, a bunch of food scraps, a bunch of leaves, some peat moss, some shredded newspaper and about 30 compostable plates. Those plates are still there since July, but they are slowly breaking down. I will be tearing them up before December. I gave those suckers 4 months (16 weeks) to do it themselves. I think they need some of my help. Oh, I almost forgot and ONE SUNCHIPS bag!
V. Procedure: Cover the SunChips bag with the bedding mixture and let is decompose with the help of the various decomposers that inhabit a Wonder Wormin bin. Did you know there are more than Red Wigglers in a bin? That’s saved for another post.
Bag in the bin. The plates are removed for better viewing.
VI. Observations and Data: When the SunChips bag was first put into the bin on 11/10, the bin’s temperature was 60F. On 11/18 the temperature was 58F. When uncovering the bedding and looking at the bag, without taking it out of it’s place, the bag looked as it did at the initial start of the experiment.
It looks like things aren’t happening……… BUT WAIT!!!!
Look there's a rip in the bag!
The bag ripped when I took it out of the bin! This is a sign. The bag is breaking down on some molecular level! I think……I have no idea, but for it to rip when I gently lifted it to take a picture, something must be breaking down within the bag!
VII. Discussion: Anyone want to discuss with me???? more later…
Happy Wormin’
I think your observations are right-on. Brittleness is a key feature in the early stage of biodegradation of PLA and other bio-plastics. In fact, once it reaches brittleness it may already be about 30% internally biodegraded- its just not obvious at first.
What you need now is some level of heating in the compost to speed the intrusion of moisture into the inter-laminar layers of PLA and to widen the cracks.
Thanks for your comment William! Are you a vermicomposter? I don’t want to raise the temperature in the bin too high. I may add some bread products over the winter. That seems to add some heat and the worms will eat them. I usually don’t add bread products over the summer. They attract too many other creatures. Do you have any other recommendations to raise the temperature in the bin without killing the worms? besides bringing the bin indoors…