Open house attendees watch a KMB single-screw machine with a 75-inch screw diameter extrude thick-wall PE pipe at KraussMaffei’s Kentucky plant. (Plastics News photo by Bill Bregar)
FLORENCE, KY. (Nov. 8, 2:55 p.m. ET) — Germany-based Ettlinger Kunststoffmaschinen GmbH has sold five of its rotation filters to North American customers since it launched Ettlinger North America last year, officials said at a KraussMaffei Corp. open house.
Ettlinger will open a U.S. headquarters by next summer, in the Chicago area, according to Mike Diletti, North American sales manager. The operation will house offices, spare parts and a material testing area, he said. Diletti is looking at locations now.
About 45 people attended the KM open house, held Oct. 4 in Florence. They saw two production lines.
A KraussMaffei Berstorff co-rotating twin-screw extruder, a model ZE 52, fed recycled and off-spec polystyrene into an ERF — Ettlinger rotation filter. KM had added a little polyester to the mix, and the EFR removed it, before moving the clean material to the pelletizer.
The other running KraussMaffei Berstorff extruder was a single-screw machine with a 75-inch screw diameter, making thick-wall, 4-inch polyethylene pipe. The line sported several features to boost productivity and accuracy.
KraussMaffei Berstorff’s internal pipe cooling (IPC) system sucks ambient air through the length of the pipe, to cool the inside of the pipe. That allows the pipe line to run faster, with a shorter cooling zone. The pipe ran through a conventional water cooling area. The PE pipe line also sported equipment from Inoex LLC of Lancaster, Pa. An Inoex ERS 250 ultrasonic measuring system continuously measured wall thickness, diameter, shape and other parameters. The pipe extruder also was equipped with an Inoex feeding system.
The IPC and Inoex instruments — plus downstream equipment such as the haul-off and saw — are all linked through the extruder’s C5 controller. That means, for example, that if the Inoex detects changes in wall thicknesses, it can signal the extruder to change speeds.
“It’s a complete package. It’s all integrated. It’s all talking to each other,” said Mark Giesey, operations manager of KraussMaffei Berstorff’s extrusion division.
Recycling was a major focus of the open house. The Ettlinger-equipped twin-screw ZE extruder had a screw diameter of 52 millimeters and the recycling line was running at 800 pounds an hour.
Martin Mack, vice president of research and development for extrusion at KraussMaffei Berstorff, said co-rotating twin-screw extruders do a good job with recycling of wet plastic scrap that comes from washing operations. “They can handle a large amount of moisture,” he said in a technical presentation at the open house.”
Running PET on a single-screw extruder requires pre-drying, a major investment in equipment, he said.
“With the twin-screw extruder, we do not need the pre-drying step,” Mack said. Moisture gets mechanically removed in the barrel, and vented out. So while the initial cost for the extruder is higher for a twin, the overall operating cost is lower, he said.
Diletti said Ettlinger North America has sold five systems that are in operation at recyclers that do compounding. Two of the customers each have two lines, giving the Ettlinger important repeat business.
Two more sold ERF systems are on boats coming over from Ettlinger headquarters in K"nigsbrunn, Germany, he said. Several other orders are pending, he said.
During a breakout session, Diletti explained what he called the “continuous and stable” operation of the ERF technology.
“It works in a completely different way from other melt filters,” he said.
Most filters push the melt through screens, which need to be frequently flushed. The material from the extruder enters the Ettlinger filter, moving through a rotating drum-shaped filter. On each rotation, contaminants get scraped off by a knife edge. “We’re just constantly cleaning the contamination off the drum, all day,” Diletti said.
Unmelted waste material, such as paper and rubber, gets immediately removed via an auger screw.
Diletti passed around samples of material from one customer that is using an Ettlinger ERF to remove aluminum from a scrap mixture of polystyrene and 20 percent aluminum foil. The recycler then sells the aluminum, he said.
“You’re able to take material that was previously worthless and turn it into something that’s worth quite a bit,” Diletti said.
The speed of the drum gets automatically controlled by pressure sensors — so the unit can speed up if it hits a heavy burst of contaminants.
Constantly cleaning the screen also helps avoid other problems, Diletti said.
“The exit pressure out of the filter is rock solid,” he added.
Some customers in Europe are running from the filter directly into a film line, he said.
Good material passes through holes in the drum-shaped screen, and on to the pelletizer.
Diletti said Ettlinger filters can handle up to 4,000 pounds of material an hour. The company is working on a larger ERF, he said.
“You only change a filter every few weeks or months, depending on what you’re running. And then, you can burn the filter in an oven and reuse it. So the filters last a long time,” Diletti said.