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How It Works: Mechanical Recycling

Mechanical recycling is the most desirable form of recycling because of its low cost and high reliability for producing usable recyclate.

There are two types of mechanical recycling, primary (for pre-consumer waste) and secondary (for post-consumer waste). Pre-consumer waste comes is manufacturing scraps and typically does not require the same collection and cleaning process as post-consumer waste.

There are four mechanical ways to collect and sort recycled material: source-separated, dual-stream, single-stream1, and mixed-waste collection2. The single-stream process is most commonly used and is outlined below.

This article deals with the basics of how mechanical recycling works. Visit Market for recycled plastic to learn how recycled plastic is turned into a sellable product.


How it works: single-stream mechanical recycling


Types of plastic sorting

To effectively bale and sell plastic recyclate, plastic needs to be correctly sorted. There are a number of ways to do this; we've outlined five below.

  • Manual Sorting: This method of sorting is very straightforward but requires a ton of manpower. Operators visually identify plastic based on their RIC, shape, colour, appearance and any trademark.
  • Float and Sink Sorting: The float-and-sink process sorts by flotation since plastics have different densities. The washed and chipped plastics are sent into tubs of water, and the pieces that float or sink are separated. This process is fast, inexpensive, and can be considered a washing stage.
  • Froth-Flotation Sorting: Materials are first treated with a surfactant and then put into water. Plastics that would normally sink in water are suspended in the water-surfactant mixture. Then, air is pumped into the system. The air bubbles adhere to some plastic pieces based on their resin type, and those that are not affected by the air bubbles sink to the bottom. The key advantage of this method is the ability to separate PET from PVC.
  • Near-Infrared Sorting: Near-infrared (NIR) sorting sorts plastic using infrared light transmission. Plastics absorb light of specific wavelengths unique to their chemical composition, allowing for the identification and separation of different types of plastic.
  • X-Ray Fluorescence: X-ray fluorescence generates a spectral fingerprint based on a plastic's chemical composition, and from this, it can be sorted into its resin type.


Can ECLIPSE™-enabled material be recycled?

Yes! First and foremost, all Smart Plastic products are designed to be recycled. The addition of our technology does not negatively impact the recyclability of the products or the recycling stream. If the material still has the mechanical characteristics of its original product, it can be recycled.

Are Materials Recovery Facilities (MRFs) and Plastic Reprocessing Facilities the same thing?

No. Sometimes they are close in proximity to each other, but they are owned by two separate companies (usually) and have different purposes. MRFs sort and sell plastic to Plastic Reprocessing Facilities. Plastic Reprocessing Facilities turn recycled plastic into usable products for plastic manufacturers.

How many recycling facilities are there in the U.S.?

As of 2018, there were over 600 materials recycling facilities across the United States.

Why is single-stream recycling most popular?

It increases the participation rate from consumers, effectively increasing recycling rates, and it saves on manpower cost and collection time.

How much waste do Material Recovery Facilities handle annually?

Around 120,000 tons of waste is handled per year at Material Recovery Center (MRFs), that’s 1,200,000 tons of waste every 10 years. Plastic Reprocessing Facilities handle 56,000,000 lbs plastic every year.

Do materials get recycled into the same product?

This depends on the material used to make the product and the company that buys the recycled material. Certain materials like glass and metal can be reused indefinitely, whereas plastic is usually down-cycled, meaning the recycled material is used to create a lower-value product.

Why is single-stream collection the most popular form of curbside recycling?

This option requires very little work on part of the consumer and does not require specific recycling trucks. All recycled waste can be collected in the same spot. Single-stream collection increases recycling rates because consumers don’t need to sort their recycling themselves.

Are recycling facilities privately owned?

Recycling plants are privately owned or are a government entity.

Is there a national law that mandates recycling in the United States?

There is no law that mandates recycling in the U.S. State and Local governments are in charge of their own recycling mandates.



We don't just talk the talk, at Smart Plastic we prove everything we say with credible third-party testing. Below you will find the corresponding tests that apply to all our claims.

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