North Carolina-based eFactor3 says air classifiers, such as the Westeria AirLift it distributes in the United States, are a crucial piece of equipment when it comes to the type of precision sorting necessary in some plastic recycling applications. One such application is in polyethylene terephthalate (PET) bottle recycling, “in which the valuable PET fraction can efficiently and thoroughly be separated from lightweight contaminants such as PE films or paper labels” using the AirLift.
The Germany-made Westeria Airlift is capable of sorting fractions made up of components that differ in specific weight, according to eFactor3. The company says the AirLift has proven its worth in Germany, where that nation’s Packaging Act specifies a material recycling rate of 58.5 percent for plastics packaging, a rate that is set to rise to 63 percent starting next year.
The regulations disregard economic factors such as the oversupply of plastic scrap and the current reduced prices for virgin plastics, says the equipment company. “This means the requirements on the quality and purity of the input available for recycling are increasing,” states eFactor3. “If these greater quantities of recycled material are to be obtained from post-consumer [scrap], greater attention has to be paid” to the sorting stages ahead of reprocessing and compounding, adds the company.
Conventional over-conveyor extractors (or air classifiers) are well suited to separating different weight fractions in mixed material streams, says eFactor3. The company adds, however, that they cannot always “cope when it comes to differentiating presorted or similar lightweight components, which is why the Westeria AirLift plays a key role. The Airlift can replace conventional air classifiers in existing installations, where it can then separate plastic film from paper or different plastics from one another.”
The AirLift system consists of three components: the SpeedCon high-speed conveyor belt; the AirLift unit itself; and an AirWheel downstream to assist with output.
AirLift units can be configured in widths from between 1,000 millimeters (mm) to 3,500 mm (3 feet, 3 inches to 11 feet, 5 inches). Maximum ouput capacity, according to eFactor3, is 5.6 metric tons per hour.
“Levels of purity in excess of 95 percent are achievable depending on the input material,” states eFactor3. “For instance, an analysis of AirLift systems installed in the mixed plastics infeed to a near infrared (NIR) sorter revealed that, for a working width of 2,800 mm (9 feet, 2 inches), more than 90 percent of the desired film fraction [had been] reliably separated.”
Thus, says the equipment company, the system “considerably reduces disposal costs and increases recycling cost efficiency. Eliminating the film from mixed plastics facilitates NIR sorting and distinctly improves the sorting result.”
For existing plant operators, eFactor3 says the complete three-part AirLift system can be used as a sub-component of a more comprehensive sorting installation. “Its design also allows it to be straightforwardly retrofitted, if necessary,” says the firm.