Meet Murf.

I want to introduce you to one of my best friends: Murf. He isn’t very popular, he doesn’t get out much, and he smells pretty bad sometimes (but that’s not his fault), so I don’t blame you for not having met yet.

So here’s Murf:



See? How friendly!

*MRFs are challenging to photograph because they’re so big.

This is a Material Recovery Facility. A MRF. Pronounced “Murf”. These facilities are instrumental to the successful sorting, processing, and shipping of recyclable materials. When you throw something in the recycling, it comes here, to Murf.

Think of Murf like a big metal dragon that chews up mixed recycling and poops out perfectly square cubes of compacted metal, paper, cardboard, and plastic.

I used to think of recycling like this, and a MRF is the closest thing you’ll find to it:

Video from “Recycle Rex”

Some MRFs are fancy. These have many conveyer belts, magnets for capturing metal, computer laser eyes called “optical sorters” that scan and separate plastics by the little numbers on them, and metal cages holding the sorted goods together until they’re ready for the next step in recycling: compaction and bailing.

Other MRFs consist of a single conveyer line, a combination of mechanical and hand sorting, and large open dumpsters and piles of material on the floor replace the metal cages.


The fancier and more technologically advanced the MRF, the more expensive it is to own and operate, so municipal budgets and haulers determine what the recycling system can financially support.

The operating standard of the MRF can impact the material outputs as well. A fast moving MRF can sort more material, but it might make more mistakes. A slower MRF will make fewer errors, but it might not be able to keep up with the inflow of recyclables and end up costing more in overtime manpower.

When I was in Portland, OR, I saw a single-conveyer line MRF that relied nearly 100% on manpower to sort materials from a public drop-off facility. Meanwhile, that same summer in Seattle, WA, a brand new multi-million dollar MRF opened with optical sorters, magnets, and higher belt speed.

Is one of these better than the other? They were both suited for their jobs, they both achieved a high recoverability rate, they both created long-term jobs in the local economy, and they both solidified recycling in their communities. The bells and whistles are nice, but community interest is better.


Let’s look at a couple features on most MRFs in the order you might find them while going down the conveyor belt.

Star Screens and Rollers

Incoming recyclable material comes in a lot of shapes and sizes. To best sort the material by type, it helps to get rid of the big stuff first. Star Screens and Rollers spin the material forward; they send lighter items (big sheets of cardboard, newspaper, office paper, and plastics) up onto one conveyer line, and heavier items (metal, glass, heavier plastics) down another direction.


Star Screens and Rollers have one kryptonite: flimsy plastic (aka film plastic). Common film plastic items include plastic shopping bags, plastic trash bags, plastic wrap and cling film, and pallet wrap. These items wrap around the rollers and turn them into a useless mess. Film plastics gum up the works and grind the whole MRF to a halt. Fishing line and balls of string do the same thing.



Magnets can be placed at multiple points along the MRF line, and they’ll pick up ferrous metals (contain steel or iron). The non-ferrous materials (copper, aluminum, brass) can have a higher market value, so those are collected as well.


Common Ferrous Metals & Items:

Steel, Light Iron, Cast Iron, Appliances (Washer, Dryer, Refrigerators), Cars/Trucks

Common Non-Ferrous Metals & Items:

Copper, Brass, Aluminum, Stainless Steel, Electronic Scrap (E-Scrap)

Optical Sorters

These computerized laser scanners are often the hardest working piece of machinery on the MRF. They rapidly scan mixed plastic items and sort them into categories based on what kind of plastic they are. Now, a human could totally do this by picking up each item, looking for that little number inside of the chasing arrows symbol, and best-guessing for plastic items without labels. If this were the case, we would have to go back to a system where only certain numbered items are allowed into the recycling, and it would take forever, and be prohibitively expensive.


It’s hard to see, but the beam of light is the “optical sorter” component, and it uses a puff of air to either push the plastic item up and over to a conveyer belt, or let gravity take it down to a different conveyer line.

The optical sorters use a laser eye and to quickly assess what material type it is, and then decides whether to use a strong, weak, or no puff of air to push the exact item into the right direction onto the next conveyor line. Sadly, even the best optical sorters can only see so many things at a time, so post-sorted material tends to be large quantities of #1, #2, and a mix called #3-7.

Seriously, these things are impressive. I’ve also seen them at a glass processing facility sorting crushed glass into three different color categories. They’re super expensive to own and maintain, but they do a good job quickly and help facilities accept more types of plastic.

Hand Sorters

Ok so let’s give a big hand to the real heroes, the people working hard every day so that we don’t have to… the hand sorters. Sometimes, sorting by hand is the fastest and most efficient way to get materials off of the conveyor belt and into their correct categories. They’re also experts at spotting and fixing mistakes that the mechanical components make.

Health and safety is highly important to the hand sorters, so they should all have plenty of access and options for personal protective equipment: hard hats, glasses, gloves, face masks, and ear plugs are a mandatory basic. Maintaining a clean work environment when you’re working with waste is challenging, but there are several steps towards keeping people healthy and safe. Keep walkways clear of debris, mist water down from the ceiling to reduce dust in the air, and everything has to be well lit.

So please, let’s all give a big hand to the hand sorters.


What’s Next?

After the material is sorted into groups of sellable piles, they are compacted into cubes. It’s very satisfying to watch.

Yes, it’s EXACTLY like Wall-E


The cubes of recyclable material are stored on site until there are enough to pack a shipping container with. Then they’re loaded up, driven to the nearest port, and sent overseas to a re-manufacturer. There are some of these re-manufacturers in the US, but most of our stuff goes away, gets turned back into products, and then returns as new products.


For example, Zhang Yin, is recognized as an impressive entrepreneurial woman from China who become a billionaire in the recycling industry. She noticed that China sent over thousands of full containers on ships to America, but that they were coming back empty. She filled up these empty containers with bales of used American paper, recycled it into new paper in China, and then American markets would buy it back! At first she got the post-consumer paper for nearly nothing because it was so plentiful, the cost of  shipping was low from America to China because captains were happy to have their ships full of cargo. Also, you can charge more for paper with post-consumer recycled content. This smart lady made money on every end of this deal.

China’s Queen of Trash


Metals get melted down and get made into new metal products. Paper gets shredded and is made into new paper. Plastics get melted down and made into new plastics. Glass gets sorted for color, gets melted down, and is made into new glass. It’s the circle of life, and it ends when you put something in the garbage can.


Key takeaways:

  • MRFs are super cool machines that make recycling work at a large scale
  • They’re not perfect, so help them out by only putting recyclables into your recycling
  • Keep in mind the people who work at MRFs and don’t put anything dangerous in your recycling
    • Paint/Batteries/Florescent Lightbulbs
    • Household cleaners
    • Needles
    • Asbestos  materials

Thanks for learning more about MRFs! If you have additional questions, email me at

One thought on “Meet Murf.

Add yours

  1. Thanks for the info. I call myself a professional garbage picker and I’ve seen a lot of non-recyclables in people’s recycling bins, including straight up garbage (people treating their recycling bin like a garbage basically), paint cans, turpentine and other similar junk, laptops, and even a .22 calibre rifle. I’ll bet the hand sorters see lots of other crazy stuff!

    Check out my blog if you wish, I focus on picking household garbage and recycling and find some pretty interesting things. I hope to someday soon visit a recycling plant and see an MRF in action.


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