Recycling facilities (called Materials Recovery Facilities-hereafter known as MRFs) do NOT mix together everything from a certain resin type. The numbers inside the recycling circle tell you nothing about recyclability and only tell you what general category (resin type) of plastics something belongs to. (Yes, even though it has a recycle symbol, it still tells you nothing about recyclability, recycled content, etc.) A perfect example of this is #1 (PETE or polyethylene terephthalate.) #1 bottles and #1 tubs are not recycled together. Another really striking example (and something I often use in my classes) is #6-polystyrene. Block foam or styrofoam is a #6, but so are Solo party cups. Obviously, these types of plastics are very different, even though they're both polystyrene. They cannot be recycled together.
Dear EarthTalk: Why can’t plastics of all types, instead of being initially sorted, simply be melted together to be separated later? It must be a monumental and error-prone task to separate truckloads of plastics. — L. Schand, via emailThe reason plastics aren’t typically melted together and then separated later is a matter of both physics and economics. When any of the seven common types of plastic resins are melted together, they tend to separate and then set in layers. The resulting blended plastic is structurally weak and difficult to manipulate. While the layered plastic could in theory be melted again and separated into its constituent resins, the energy inputs required to do so would make such a process cost prohibitive.As a result, recycling facilities sort their plastics first and then melt them down only with other items made of the same type of resin. While this process is labor-intensive, the recycling numbers on the bottom of many plastic items make for quicker sorting. Many recycling operations are not only reducing sizable amounts of waste from going into landfills but are also profitable if managed correctly.
The process of sorting plastics for recycling is labor intensive (mostly done by hand) but the recycling numbers on the bottom are rarely, if ever, used to help at this point in the process. The only time when the # may be used is when a material comes through that is wildly different from the "usual" materials. Someone on a sort line or who runs a MRF could conceivably then check the # inside the recycle symbol to ascertain the resin type. In practice, though, I've never heard of this being done. People who own and operate MRFs are very good at sorting plastics, mostly by sheer recognition. When looked at from this point of view, it's a feat that MRFs are able to keep up with all the thousands of different types of plastics constantly on the market.
That "reclaimed polymer can be used to create new items just like their virgin plastic forebears." is technically correct, although this is rarely the case. It's rare for plastic items to be recycled into what they were originally. It's much more common for them to be downcycled into a different product (milk jugs into benches, for example) that then can't be recycled any further. (Another example that illustrates this point: plastic lumber is often old plastic bags mixed with sawdust. While it is nice that this material is made from recycled plastic, it cannot be recycled at the end of its life cycle.) Also, this is a bit nit-picky but I wouldn't necessarily use the term "common types" of plastic. The 7 #s are resin codes. They are the 7 codes that are currently in use. Every type of plastic fits into one of these 7 codes, even if they are very uncommon (see more about #7 plastics below.)Manufacturers of plastic items choose specific resins for different applications. Recycling like items together means the reclaimed polymer can be used to create new items just like their virgin plastic forebears. The seven common types of plastic are: #1 Polyethylene terephthalate (PET or PETE); #2 High-density polyethylene (HDPE); #3 Polyvinyl chloride (PVC); #4 Low-density polyethylene (LDPE); #5 Polypropylene (PP); #6 Polystyrene (PS); and #7 Other/Mixed (O).
I have a real problem with this paragraph, so I'm going to do it bullet point style.One complicating factor is trying to recycle unmarked plastics and those embossed with a #7 (representing mixed resins, also known as polycarbonate). According to Earth911, a leading online source for finding recyclers for specific types of items across the United States, in some cases #7 plastics can be “down-cycled” into non-renewable resin, in other cases recycling operations just send their unmarked and #7 plastics into local landfills.Even though recycling operations have developed relatively efficient systems for generating reclaimed resins, many environmentalists recommend that consumers still avoid plastics as much as possible.
- I would say the more complicating factor for recycling plastics is that there are literally hundreds, if not thousands, of different types of plastics, even within a resin code. (Fillers, dyes, etc are added to the resins to make them behave in specific ways.) There is no standard of one type of plastic within a resin type.
- The other really complicating factor is lack of markets. Every recycling decision is based on whether there is a market for that material and the market is based on there being consumers willing to buy whatever product is being made from that recycled resin. I've heard some people go so far as explaining it thusly: If you're not buying recycled materials, you're not recycling. Consuming willy-nilly is not excusable by recycling. If the materials you put in your recycling bin don't have a strong market behind them, the system is not a closed loop.
- As far as unmarked plastics: I would assume that most MRFs don't even mess around with unmarked plastics. In other words, if something is made from plastic but they can't determine the type, it will likely end up in the landfill.
- I don't know that #7 always is a mixed resin and it's certainly not always polycarbonate. #7 plastics are simply "other" They are plastics that do not fit into any of the other 6 categories and these days, this includes PLA (see below.)
- On the west coast, unknown plastics are often sent overseas instead of to the landfill, in mixed plastic bales. These are then hand-sorted (usually in China) I cannot guarantee what happens to them at that point in the line.
Agreed. Recycling is not the only solution and we aren't ever going to be able to recycle our way out of the mess we're in. More important solutions include reducing the amount of consumption we do in general and reusing what we can at every opportunity. The only gripe I have with this part of the article is the very end. I'm not sure that metal, glass or wood is always "recycled more efficiently" than plastic. All recycling takes energy and resources to complete, although in every case I've ever seen, this will be less energy and resources than it would take to extract the resources and make the product from scratch.
“Simply recycling these products does not negate the environmental damage done when the resource is extracted or when the product is manufactured,” reports EcoCycle, a Colorado-based nonprofit recycler with an international reputation as an innovator in resource conservation. The group adds that over the past half century, the use of disposable packaging, especially plastic, has increased by more than 10,000 percent.Along these lines, products (or packaging) made out of reusable metal, glass or even wood are preferable to equivalent items made from plastic. For starters, an item of metal, glass or wood can be re-used by someone else or recycled much more efficiently than plastic when it does reach the end of its useful life to you.
This is where the article really started to irritate me. PLA plastic does NOT break down in a home compost system (at least not in my experience!) I've never heard of or seen anyone with a home compost system that can handle PLA plastics. PLA plastics can break down in a commercial composting facility, but even then, these facilities are very careful about what they will accept. With new products coming out virtually every day, each product needs to be tested to make sure it will break down. Finally, when people see that a plastic product is supposedly biodegradable, they often assume that means it will break down into useful components in a landfill. I know of no proof of that. Even if plastics did break down in a landfill, you then have to consider increased methane production and the shifting of the landfill structure if things are breaking down on some regular basis. To see or laud PLA plastics as necessarily better than traditional plastics is folly.Wood products and other items crafted out of plant material, even so-called “polylactic acid (PLA) plastic” made from plant-based agricultural wastes, can be composted along with your yard waste and food scraps, either in your backyard or, if your town or city offers it, through your municipal collection system.
That sentence I can get behind! Indeed!Happy reducing, reusing and recycling!
As I said earlier, everything I've written here is "to the best of my knowledge." If you have specific examples of where I'm wrong, please let me know and I will update the post.
I get frustrated by encountering scores of people who are so excited about this "new" biodegradable plastic they've found and paid extra money for (but then are going to throw in the landfill.) Or, people who get upset with our collection system because we don't use the resin code system. (Trust me, I'd love to, it would certainly be easier...) Plastics recycling is a complicated issue. Unless and until there is some standardization or clarification of the resin code system, many communities will continue to not use it because it simply doesn't work for the materials they need to collect and send to end markets. In my opinion, articles like this one that try to simplify a complex issue only continue to confuse the public. I hope I've provided some more insight into the complicated world of plastics recycling. If you have further questions, please feel free to contact me.