Flottweg SE, Vilsbiburg, Germany, is bringing its trademarked Sorticanter technology to the North American market.
Sorticanter separates plastics by density using centrifugal force. This is significantly faster than the more common method of static separation in a liquid-filled tank, which depends on gravity, according to Flottweg.
"This is unique technology for the U.S. market," said Oliver Willmann, the U.S. sales manager at Flottweg Separation Technology Inc., the firm's Independence, Ky., U.S. subsidiary, in an interview at the Re|focus Recycling Summit and Expo held in April in Orlando, Fla.
Previously, the Sorticanter was primarily sold in Europe.
Before sorting, plastics such as PE, PP, PET and film and materials such as cable insulation or carpet fibers are shredded. Impurities such as paper labels are washed out of the shredded material. Particle size after shredding is typically 2mm to 16mm.
The shredded plastics go into a liquid-filled homogenization tank, then the slurry is pumped into the rotating bowl of the Sorticanter. The bowl accelerates and the centrifugal force packs heavier material against the wall of the bowl. The material against the wall is conveyed by a rotating screw to the conical end of the bowl and is discharged.
The lighter material concentrates on the surface of the liquid inside the bowl, where the screw moves it out of the opposite end of the Sorticanter. The carrier liquid is recycled back to the mixing tank.
The heavier material is sometimes separated and contaminants removed again before it is ready to be processed further. The lighter material can be dried, ground again, if necessary, and sent through an extruder.
The liquid used is typically water, but it must have a density that is between the densities of the plastics being separated. That means oils or brine may need to be used.
Willmann said the Sorticanter improves sorting accuracy, which results in higher value for the sorted material. It can handle some materials that are not suited for static separation and additional dewatering using screen centrifuges is not necessary. It also eliminates issues with air bubbles that can affect separation.
There are two Sorticanter models. Throughput is based on the density and other characteristics of the material being sorted, but an example would be sorting of PET bottle material. The K4D-4/444 model sorts about 1,700 pounds of it per hour, while the larger and more powerful K6E-4/444 sorts about 4,400 pounds of it per hour.
Flottweg, founded in 1932, manufactures decanter centrifuges, separators, belt presses and other mechanical separation systems that are used in a variety of industries, including the chemical, food, pharmaceutical and sewage industries. It has 826 employees worldwide, including 65 at its Cincinnati-area U.S. headquarters.
Ron Shinn, editor
Contact: Flottweg Separation Technology, 859-448-2300, www.flottweg.com
Ron Shinn | Editor
Editor Ron Shinn is a co-founder of Plastics Machinery & Manufacturing and has been covering the plastics industry for more than 35 years. He leads the editorial team, directs coverage and sets the editorial calendar. He also writes features, including the Talking Points column and On the Factory Floor, and covers recycling and sustainability for PMM and Plastics Recycling.
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