Melt filtration for contaminants

At the Compounding World Expo 2018 (June 27-28) in Essen, Ettlinger shares a booth with the Maag Group (Stand 123) where it will present its expertise in all filtration tasks connected to thermoplastic compounding and recycling plus the entire post-extrusion process. One highlight is Ettlinger’s ECO family of filter systems for easy-flowing materials as well as the recently launched ERF350 melt filter, which has an extra-high throughput and the power to handle feedstock with higher contaminant levels. The Maag Group has a broad portfolio of products specially tailored to the needs of the compounding industry, which apart from filtration systems also includes pumps, strand and underwater pelletizing systems and pulverizers.

 

The decisive hallmark of both the ECO and the ERF filter series is their long runtimes virtually free of interruptions. This advantage derives from the rotating cylindrical screen with conical holes over which the scraper slides, reliably separating all retained contaminants from the melt with every rotation and feeding them immediately to a discharge unit. This effectively avoids blockage, even if the filter is in use for several weeks or months at a time. The result: absolutely constant pressure with significant benefits for sensitive applications like film, sheet and pipe extrusion or downstream strand or underwater pelletizing systems. Thanks to the special discharge principle, these Ettlinger filters moreover have the lowest melt losses in the industry, leading to low operating costs and hence a rapid return on investment.

 

 

The melt filters in the ECO series are mainly designed for very easy-flowing materials such as PET or PA containing up to 1.5% contaminants but are also suitable for filtering polyolefins and polystyrenes. They are offered in two different sizes with a maximum throughput of 1000 kg/h or 3000 kg/h. Their typical applications include the manufacture of PET packaging tape, films and sheets as well as fiber production and PET bottle recycling. Compounders choose ECO filters to separate gels and agglomerates reliably from virgin material. In particular, the ability to recycle PET packaging tape and the fact that the melt filters can be directly integrated into PET thermoforming lines are opening up attractive growth opportunities.

 

The Ettlinger ERF series is ideal for filtering heavily contaminated polyolefins and polystyrenes as well as styrene copolymers, TPE and TPU. Foreign particles such as paper, aluminum, wood, elastomers or high-melting polymer composites can be reliably removed from materials containing up to 18% contaminants. The treatment of post-consumer plastic waste, which can have a high aluminum, rubber or silicone content, is one very common application. However, these filters are also used to convert recycled automotive plastics, where paint particles have to be efficiently removed from the recycled material, for instance, or to treat refrigerator and electronic waste. ERF melt filters are available in three different sizes with a maximum throughput of 6000 kg/h. Nearly 400 of these units are meanwhile in action very successfully every day around the world. The ERF350 is the first model in a new, performance enhanced generation. Depending on the type of material, the level of contamination in the melt and the selected screen size, it achieves a maximum throughput of 3800 kg/h – around 28% more than its predecessor, the proven ERF250 – for the same filtration surface, the same small footprint and similarly high energy efficiency.

 

Ettlinger Kunststoffmaschinen GmbH was founded in 1983 and engaged in the development and manufacture of high performance melt filters and injection moulding machines. Ettlinger has been part of the Maag Group since 2018.