Markets for recyclable materials change constantly. Following is a snapshot of what happens to curbside single-stream recycling.
Recycling saves energy throughout the production cycle because recycled materials require less processing than raw "virgin" materials. According to a report by the Environmental Defense Fund, recycling a ton of material collected by a typical curbside recycling program saves the energy equivalent of $265 worth of electricity, petroleum, natural gas and coal--that’s after deducting the energy used to collect materials.
Plastic containers and rigid plastic are generally recycled in the Pacific Rim. Chasing arrows (#1-#7) found on most plastic items helps identify plastic resins. Plastic types are separated whenever possible to increase the market value of the material.
#1 plastics (such as PET water bottles), can be recycled into fiber products, such as carpets, fiberfill, polyester fabrics.
#2 plastics (such as HDPE milk jugs) are usually recycled back into similar containers, plastic lumber, baby bathtubs, detergent bottles, and traffic cones.
#5 plastics (such as Polypropylene lid tops) are often mixed with other resins and made into items like road marker reflectors.
#6 plastics (such as formed polystyrene, or Styrofoam) cannot be recycled locally, although some packing stores accept the foam “peanuts” for reuse.
#7 plastics (such as composite plastics and rigid plastics) are recycled into more rigid plastic materials. The #7 materials also include some corn-based plastic products which are not recyclable and not compostable locally.
Glass containers are being recycled domestically, mainly into wine bottles. Glass shards from broken bottles are mixed with asphalt for road base. Recycling glass saves energy. Making glass from raw material such as soda and pot ash requires the material to be heated to 1800 degrees and then held for 45 minutes. When remanufacturing glass, the glass pellets need only be heated to 1400 degrees.
Aluminum cans are being recycled domestically, mainly into aluminum cans. Aluminum is unique in that the material can be recycled over and over again. It also has one of the shortest journeys from the sort line back to the shelf. An aluminum can you put out for recycling today, can be back on the shelf at your local grocer in as little as 30 days.
These containers are made of high quality paper and if marketed domestically, may be recycled into tissue products.
Clean white paper (such as generated by an office) is generally recycled domestically and made into more paper. Mixed paper captured through the single-stream sort line is usually shipped to the Pacific Rim where it is also made into paper products such as chipboard (cereal and tissue) boxes. Recycling paper saves energy. Making paper from paper pulp rather than wood requires much less energy as it is not a heat-intensive process.
Most of Sonoma County’s single-stream recycling is sorted and baled for shipping at Recology’s Materials Recovery Facility in Santa Rosa.
The process starts when giant mounds of recycling are sorted daily in a process which incorporates both mechanical and human sorting. The first sort is done by hand where large pieces of cardboard, rigid plastics, garbage, and plastic bags are removed.
Next, the material is pushed up a large conveyor belt with a row of rods that contain series of offset lobes (similar to a cam shaft) which “float” the lighter material, such as paper, to an upper belt which feeds directly to the baler where paper and other fiber products are collected and prepared for shipping.
Beverage/food/household containers and smaller bits of paper fall through the first set of cams onto another belt. These are fed up a second incline conveyor containing a smaller set of offset lobes to capture the smaller pieces of paper. That belt feeds to a baler for processing.
The beverage/food/household containers which fall through to the container line pass under a strong magnet which removes all steel cans and other magnetic materials. Remaining plastic containers are sorted into different grades by hand, and an “eddy” current pushes aluminum cans into a collection hopper.
For this complex sorting process to operate efficiently, it is important to make sure the recyclables placed in your blue single-stream container are free of contamination and garbage.
If you would like a tour of the Materials Recovery Facility located at 3400 Standish Ave., Santa Rosa, call (800) 800-0291.