What happens after mixed recycling gets tossed into your bin? Let’s walk through the recycling process for plastic:
Waste Haulers collect mixed recycling materials, also known as single stream, from homes and businesses. In Sioux Falls, there are over 20 licensed waste haulers, so you have a wide selection to choose from for who picks up your trash and recycling (see a list of local haulers). After the material is picked up by your hauler, it is brought to Millennium Recycling (If you don’t have a waste hauler you can also bring it directly to the public dropoff bin).
The only types of plastic accepted in the single stream include Plastic Bottles, Tubs and Jugs (plastic bags are also accepted but we’ll address those in a separate post).
At Millennium, the mixed recyclables are dumped into a huge pile and a team member checks to make sure no large, bulky items are in the mix that could damage the equipment or hurt employees (i.e. tires, metal chunks, wood pieces, etc).
The materials are moved onto a conveyor belt where workers pull out plastic bags to be recycled, and other items found that are not recyclable or might jam up the equipment (i.e. clothing, wire hangers, garden hoses, etc). The cardboard and paper get separated out using screens (learn how) and the remaining items (plastic, glass and metal) fall through and continue on. Metal is separated off using a magnet for steel and an eddy current for aluminum (learn how).
Plastic containers left on the line are sent through a machine called an optical sorter to sort them by type. Infrared laser beams are used to shine on the plastic items, which lets the sensors detect different grades of plastics. Puffs of air then separate the types into different bins.
The separated plastic containers at Millennium get baled and then transported to plastic processors in Minnesota, Iowa, Illinois, and Ohio.
At the plastic processor, the bags are washed in flood tanks where all forms of non metallic contaminants including paper, food or sticky substances such as syrups are removed. They are then sent through magnets fitted next to the conveyor belt to remove any metallic pieces.
Next, the bags are melted into a plastic resin material, cooled and dried.
5. Chopping & Cleaning
The newly formed plastic resin then gets chopped into little pellets and washed again if needed.
The pellets are then sent to manufacturers who use the material for new bags or plastic lumber.