posted June 15, 2011 by rudi |
while the photo below is an extreme example, many of us have been confronted with ever increasing amounts of plastic that wash up on our coastlines. it’s estimated that several billion tons of debris continue to be added to our oceans each year. cue cringing.
while many folks are actively working to try to clean up the trash that ends up on beaches, we couldn’t help but ask the question: what’s happening to all the plastic that’s recovered from the ocean? couldn’t we divert this plastic and reuse it?
last year method got involved with the California Coastal Commission and helped support California Coastal Cleanup Day at a beach here in South San Francisco (note: CA Coastal Cleanup Day will be taking place September 25th this year). we thought that if we could sort the right types of plastic from all the trash, we could use it to make new bottles. ocean plastic is especially challenging because of its exposure to the elements, which changes its composition + melting temperature, making it harder to process. this is why pre-sorting is especially important. so after hours of trolling the shores of San Francisco Bay, we had gathered several hundred pounds of rigid plastic deemed suitable for the experiment.
we then sent the collected plastic down to a recycler in LA who was kind enough to help us with our project. the process we undertook is really no different than what happens to all those bottles you throw into the recycling a home.
1. first, the material is chopped up into smaller pieces, resulting in a pile of plastic bits that look something like this:
2. then the little bits of plastic are put into a giant washing machine that removes any junk that may have come along for the ride. at this point in the process, many recyclers will optically sort the material and grade it by color (a step we did not take with the ocean plastic).
3. the chopped up and cleaned ocean plastic is then dried and put through an extruder—a machine that heats up and blends the material into a molten state. which results in this rather unimpressive looking blob of material.
3. but we’re not done yet. we still don’t have the plastic in the right form to make bottles. the last step is to make “pellets.” which are just little round disks of plastic. on the left, you can see plastic pellets made with our ocean plastic and on the right, plastic pellets that are made from typically recycled bottles. the color difference has to do with the fact we skipped the step of optically sorting the plastic. so we ended up with a mix of colored plastic, resulting in the black pellets you see below.
finally it was the moment of truth. could we take the ocean plastic pellets and actually make a bottle with it? (dun dun dun) after a number of tries, we were met with success. the bottle on the left was made with the ocean plastic and the bottle on the right was made with standard PCR. they’re a lovely pair, aren’t they?
this is an exciting first step, and without a doubt proved to us that ocean plastic can reincarnate itself as another bottle. we’re now working on creating a sustainable supply chain to continue doing just that. stay tuned!