With filtration fineness of 60 µm, self-cleaning ECO melt filters by Ettlinger, Königsbrunn, Germany, part of Maag and Dover, Downers Grove, Illinois, are designed to facilitate treating recycled material for use in the film, packaging tape and fiber industries. The filters help plastic recyclers remove challenging contaminants, such as paints, silicones, barrier materials, cross-linked fractions and gels, from the melt. In particular, the new filter screens will enable cost-efficient conversion of postconsumer polyethylene terephthalate (PET) bottle flakes and fines into recycled material, according to the manufacturer.
The core component of the ECO filter is a rotating, cylindrical steel screen with millions of conical holes drilled by laser, Ettlinger says. When melt flows through this screen from the outside to the inside, any contaminants are retained on the surface and continuously removed by a scraper.
Ettlinger says its filter screens feature laser-drilled microperforations that offer separation efficiency. The woven steel mesh screens have a mesh size corresponding to the cross-section of the conical holes in the filter screen, which are tapered in the direction of the melt flow. When melt flows through the screens, all contaminants larger than the hole diameter are retained on the filter surface. With the new 60 µm filtration fineness, the few residual contaminants that penetrate the screen are no longer visible to the human eye, according to the company.