The Stages Of A Single Stream Recycling System


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The recycling industry has come on in leaps and bounds in recent years. More material is being recycled than ever before – and for good reason. Humanity as a whole has come to realize the immensely detrimental effect that rubbish landfill is having on the globe. As recycling has become more widespread, the processes used for sorting out materials have improved. Today, 240 out of the 570 recycling centers in the USA run single-stream operations. Single stream recycling is essentially a production line style system where mixed recycling goes in one end, and sorted recycling comes out the other. Here are the stages necessary for that to happen.

The Stages Of A Single Stream Recycling System

Drum Feeder

Mixed recycling is transferred into a spinning drum using a mechanical claw. The spinning drum distributes recycling evenly onto a moving conveyor belt.

Initial Sorters

Line pickers pull out any large items that will not fit through the sorter. They also remove large plastic bags or ropes that might clog up machinery. This is an immensely important stage – any stoppage of the sorting machines can lead to a huge backup of recycled materials.

Large Star Screens

Star screens are interlocking star-shaped wheels that sort large items from small ones. They were originally developed in Holland for sorting tulip bulbs. The first star screens are large and primarily remove card items.

Second Sorters

After the materials pass through the first star screens, workers pull out any smaller contaminants or valuable items. This is where wallets, coins, and medical waste is removed from the stream.

Medium Star Screens

Smaller star screens pull out different grades of paper from the mix. Paper is one of the most efficient materials to recycle, as it can be repulped and repressed without any noticeable change in quality.

Glass Sorter

Glass is heavier than plastic or metal. This means that it can be separated from the stream using gravity. The glass is then ground up and sent to a specialist glass recycler, which usually melts it down and reforms it.

Magnetic Metal Sorter

Metals are then separated from the stream using a powerful electromagnet. Only around 4 percent of recycled material is magnetic metal, with most of the metals recycled being made of non-magnetic aluminum.


Once individual materials have been separated out, each material is fed through a baling machine. Baling machines use powerful pistons to compress the material into 1-ton cubes, which are then fastened with baler wire. Bales are far easier to store and transport than loose material and allow for the efficient auditing of recycled materials.


Unfortunately, lots of material that enters a recycling center cannot be reused. Plenty of plastics are incompatible with recycling processes. Some waste still has to be transported to landfill sites. Ultimately, recycling won’t spare the world of landfill waste. Instead, companies need to cut down on the production of plastics that are not compatible with recycling, and new regulations have to be placed on the world’s premier manufacturers of disposable products.


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