This story appeared in the Winter 2020 edition of Plastics Recycling.
Anzano del Parco, Italy-based Previero N. Srl seeks to patent equipment and a method for washing plastics and separating them from contaminants, particularly metal.
The method and apparatus are simple from a functional and structural point of view but also are efficient, limiting consumption of washing fluid and energy, according to the patent application.
The invention includes a washing container with inlet and outlet ports that are arranged opposite each other. It also features angled stirring elements driven by variable-speed motors to create turbulence, moving the plastic pieces upward. A speed of between 200 rpm and 400 rpm is most effective for washing and separating the plastic and contaminants.
“The method and the apparatus disclosed above enable high levels of purity to be obtained in the recovered plastics material in reduced time, owing to the immediate continuous removal of the contaminants from the washing container,” the application states. “Owing to the dual function of the mechanical stirring and floating thrust performed by the stirrers … optimum separation of the contaminants from the plastics materials is obtained.”
Patent application 20190351427; published Nov. 21, 2019