A German supplier of construction moisture-barrier sheeting recently equipped its extrusion line with an Eco melt filter from Ettlinger Kunststoffmaschinen GmbH.
Ettlinger did not identify the customer, but said the sheeting is a mixture of linear low density polyethylene and a polyolefin-based, elastic-thermoplastic material. The manufacturer wanted to use industrial regrind, but this was difficult to do with its prior double-piston screen changer. Two or three screen changes per shift were the norm, according to Ettlinger.
The Eco filter gives a trouble-free service life of four weeks, without disrupting production.
Also using the old double-piston screen changer, the starting mixture had to contain some virgin material, and the proportion of elastic material had to be increased. If there was no virgin material or too much elastic material in the regrind, it led to quality defects such as holes in the film, caused by unmelted gels, which are initially retained by the filter but then gradually pass through the screen as the filter cake grows steadily larger and more pressure builds up, according to Ettlinger.
The Eco filter uses a rotating, cylindrical filter screen with millions of conical holes. When melt flows through the filter, contaminants are retained on the outside of the screen. The waste particles are continuously removed from the screen surface and fed to a discharge shaft, which is driven be a servo-motor. With every rotation, the drum is cleaned by a scraper.
Ettlinger is based in Konigsbrünn, Germany.
Ettlinger North America LP is in Tyrone, Ga.
Tel. 630-596-7449, email [email protected]