Rudi Becker, method’s Resinator (Director of Package Development) explains the process of creating Ocean PCR, from his blog post on method’s website from June 15 of the this year.
While the picture below is an extreme example, many of us have been confronted with ever increasing amounts of plastic that wash up on our coastline. It’s estimated that several billion tons of debris continue to be added to our oceans each year.
Many folks are actively working to try to clean up the trash that ends on beaches, but we had to ask the question: What is happening to all that plastic that is recovered from the ocean? Couldn’t we divert this plastic and reuse it?
Late 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. We thought that if we could sort out the right types of plastic from all the trash, we could take ocean plastic and remake it into new bottles.
After hours of trolling the shores of San Francisco Bay we were able to pull together several hundred pounds of rigid plastic that we deemed suitable for the experiment. We had to be careful to try to only select plastics that we knew had relatively the same melt temperature which would help with processing of the material later on.
The collected plastic was sent to Envision Plastics in Southern California, 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 bin at home. Envision took the ocean plastic we collected and put it through the following process:
- First the material is chopped up into smaller size pieces of plastic. You get a pile of plastic bits that look something like this:
- The little bits of plastic are then put into a giant washing machine that removes any junk that may have come along for the ride. At this point in the process Envision will optically sort the material and will grade it by color (we did not take this step with the ocean plastic, since this was experimental).
- The now chopped up and washed ocean plastic is then dried and put through and extruder. You can think of this as a machine that heats up and blends the material into a molten state. You end up with this rather unimpressive looking blob of material:
- We are not done yet. We still don’t have the plastic in the right form to make bottles. The last step is to make what are called “pellets”. These are just little round disks of plastic. On the left you can see plastic pellets made with our ocean plastic and on the right you can see plastic pellets that are made from typical bottles you throw into your recycling bin. 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 now take the ocean plastic pellets
and actually make a bottle with it. After a number of tries we were able to setup up the extrusion blow molding equipment to make pretty decent looking bottles. Again the bottle on the left was made with the ocean plastic and the bottle on the right was made with standard PCR.
This is an exciting first step and without a doubt proved to us that ocean plastic can reincarnate itself as another bottle.