Whadya Mean I Can’t Recycle This?

It’s (Glass, Paper, Plastic, …) isn’t it?

We are usually provided with lists of what is or isn’t recyclable. This lists change, with some items moving to the do not list that were previously OK. I sometimes am asked why something is not recyclable. I smile (behind my mask of course) and I ask if they want the short or long answer. The short answer is if it does not look like the picture on the bin, it isn’t recyclable. First of all remember that it may be that the item is recyclable, just not in the mixed recycling bin. It may need to be put in a different bin or taken to a different drop off location. Thurston County has a good resource for where to take items at Where Do I Take My?…

The long answer is, of course, more complicated. It is a function of economics, science, and technology.

Economics because we consumers are only willing to pay so much for products made from recycled material. Recycling is a business, or series of businesses, and each step adds cost to the final product. For some materials this works, for others it’s too costly. Recycling is a pull not a push cycle. If there is no business that wants a material or item, then no amount of push can force it through.

Science is a factor as some materials can be recycled only a limited number of times. Paper is a good example; wood fibers break down and become smaller and less useful with each step of the process. That is why the brown compressed paper products like egg cartons and some packaging are not recyclable. They are made from paper that has reached the end of useful life. Some plastics have a limited life as well. Others take large amounts of energy to turn them back into usable raw material.

Recycling technology used in the sorting and processing is being improved all the time, but there are limitations today in sensors and sorting that limit what can go into mixed recycling.

In the recycling circular economy, there are several steps involving many companies. After collection and sorting, each type of material goes to a different company for processing and then to hundreds of product companies to make the new products we buy.

Here are the processing steps:
1) Collection
2) Sorting
3) Processing to convert recycled products to usable raw material
4) Raw material to new products
5) Consumer purchases new products with recycled content

Contamination

One of the major issues with the process is at the beginning – CONTAMINATION. The processing companies in step 3 want to buy only specific materials that are clean and with no other materials mixed in. Anything else is contamination. Sorting out and disposing of contamination is a major cost. If the incoming load of material has too much contamination the entire load can end up at the landfill. Contamination is why China and many other countries will no longer take bulk recycled material from the U.S. What is contamination?

• Any item that the sorting facility does not want. if it does not look like the picture on the bin, do not put it in the bin.
• Containers with food residue, oils, cheese, etc. (It does not have to be perfect.)
• Non-recyclable items. See the list of non-recyclable items in the resident handbook.
• Items placed in the wrong bin.
• Items that are made of more than one material such as food wrappers and containers that are paper on the outside but coated with plastic on the inside.
• Dangerous materials in mixed recycling – Broken glass, aerosol cans, propane tanks (yes it happens), etc.
• Bags of material – All material must be loose.

For the rest of this article, we will look at the first two steps in the recycling process, Collection and Sorting.

Collection

Collection starts when we consumers place used material in the recycling bins. We then pay a service to pick up those bins and transport them to the sorting facility. Early in the history of recycling, many of us had several bins and had to sort the material by type. The industry has mostly gone to so called single sort collection for two reasons. First, we consumers were extremely poor at sorting and making sure items were clean, so additional sorting had to be done at the collection site. Second, the multi container trucks were expensive to own and operate. They were not efficient, when the bin for one material type was full on the truck, even if the others were only half full, the driver had to go empty the whole load and then restart the route.

Even with single sort collection, there are items that that are really hard to sort at the sorting facility so must be put in separate containers or taken to other collection locations. Glass is an example as broken glass is both difficult and dangerous to sort out. Plastic bags cannot be put in single sort as they get wrapped around gears and shafts, shutting down the sorting equipment. Having unsorted material pile up and a dozen workers stand around while a mechanic unjams a machine is not an efficient use of resources. Plastic bags are really bad in single sort bins.

Sorting

Once recycled materials are collected they are delivered to a Recycling Sort Plant. These plants use a system of conveyors to sort through a variety of co-mingled recycling materials. The materials are spread out along the conveyor belts and are transported throughout the recycling plant while being sorted by a combination of hand sorting and automated machinery. Equipment separates and measure materials like paper and plastic by weight. Magnets are used to sort out ferrous metals (i.e. iron and steel) while magnetic eddy current sensors are used to sort out non-ferrous (i.e. copper and brass). Optical sensors can differentiate and separate different types of paper and plastics. Larger plants that service major metropolitan areas often can justify the cost of a larger amount of automation than smaller plants.

With the large volume of material that moves through these plants, the human and machine sorters have only seconds or less than a second to make a decision on any one item. Imagine if your job was to watch a conveyor of material go by and have to rapidly remove items that would cause contamination downstream.

Materials are sorted into categories that the companies who process it back to usable raw material want to purchase. Anything else is refuse and is sent to normal trash disposal. Just like us, the sorting companies must pay to have the trash hauled away. This adds to the cost of the recycled materials. Below is a list of typical categories for sorted materials. Note that there are types of plastics and other materials that are not listed. These may have low demand or are too expensive to process.

• Cardboard
• Plastic Film
• Aluminum
• Copper
• Ferrous Metal
• Newspapers
• Mixed Paper
• PET/PE Transparent & PET/PE Colored
• HDPE Natural & HDPE Colored

In future articles we will discuss processing and why materials can be used or not. Hopefully, this helps you decide what to put into the recycling bin.

-Joe Palmiter

An excerpt from this article appears in the February 2021 Panorama News.