Recology Recycling Central SFO RHRF

STEPS

Recycling Process

Curbside collection is the first step in the recycling process. The facility’s tipping floor receives the contents from about 185 local collection trucks. The gathered recyclables are then moved by a front loader into a drum feeder, which distributes materials uniformly onto a conveyor belt for reliable downstream processing. The pre-sort system, a 14-station line, is where the initial sorting is done. Trained manual sorters remove any problematic materials and non-recyclable contaminants such as wire hangers, bulky plastics, soft plastics, and ordinary garbage. These non-recyclable materials could damage the machinery.

The stream of materials is put through the automated sorting system after the initial manual sorting is finished. A number of disk screens and gravity-based systems are used in this sequence to separate materials according to their weight, size, and shape. Clean cardboard, a commodity with a particularly high volume, is isolated by the first of these machines. Rotating disks separate both heavier and lighter materials. Heavier materials like glass containers, metal cans, and plastic bottles drop onto a lower conveyor line for further processing. Lighter items continue along upper conveyors to specialized paper screens. These paper screens work in two stages: the first stage isolates the newspaper, while the second identifies mixed paper and deflects other containers for additional processing.

Next, the sorted paper is sent through three precision-engineered optical sorting units, which identify and eliminate plastic impurities like film plastic or bags that might have gotten past earlier stages using light-based sensors. Before the paper stream is compressed into thick bales using a high-capacity baler, a final manual QA/QC makes sure that any remaining garbage or non-paper materials are removed. In the process of handling heavier recyclables, smaller items like glass fragments and shredded paper are removed through intense vibration combined with pressurized air jets. Compressed air aids in differentiating lightweight waste from denser glass, and clean glass is eventually gathered into a specific pile. The leftover food and drink containers go through a magnet that removes steel cans, post which an eddy current separator ejects aluminum cans from the conveyor. This technique of utilizing opposing electrical currents enables efficient separation of non-ferrous metals.

Later in the process, more sophisticated optical sorters can classify plastics not only by their color and resin type but also by complex structures such as aseptic packaging. This MRF has three paper sorters, three plastic and multilayer carton sorters, and one sorter that completely reprocesses rejected or uncertain materials, which transfers them back into the complete sorting system for another pass.

Throughout the various steps in the process, operators track the equipment outputs to extract impurities and adjust material flows. All recoverable materials, with the exception of glass bottles, are baled into compact 3-foot by 4-foot by 5-foot units weighing about 1,300 pounds each. These bales are then readied for shipment to appropriate markets. Plastic waste is distributed domestically and internationally for re-processing into new plastic products, while paper bales are dismantled and then packed into containers, which are later shipped locally and globally for paper-based goods re-manufacture. Bottles can be delivered to local vendors for remanufacturing into new glass products. The metal bales, composed of aluminum and steel, are sent to facilities where they are recycled into new cans or aluminum goods. Steel cans and aluminum goods are manufactured from recycled metals.