Leistritz Extrusionstechnik GmbH used a bit of showmanship to roll out a quick-change version of its new twin-screw compounding extruders, and a newly designed shaft, during K 2004 in Dusseldorf.
As smoke billowed up and dramatic music swelled, Leistritz marketing officials Richard Steiner and Michael Thummert pulled back a black curtain to reveal the ZSE Maxx, which eventually will replace the ZSE HP range. The executives stood in front of the machine as they interacted with actors projected onto a large video screen.
``We optimized the volume and the torque ratio to maximize profitability,'' Steiner said at the October event.
Leistritz said that's been the dilemma over the past 15-20 years of making compounding extruders: Extruders that can pump through a high volume of plastic had to have their torque reduced significantly. The ZSE Maxx and ZSE Flexx can do both, they said.
The key is a new design of the machined spline shaft - dubbed maXXshaft - that allows Leistritz to keep the same distance between the centerline of the two screws, even as the firm uses larger-diameter screws. That means the screw flights can be cut deeper, allowing for more free volume in the high-torque machines.
The drive unit maintains the optimum screw speed and torque for each application. The drive is shrouded completely to reduce noise. The barrel is water-cooled.
Because the screws have the same centerlines as existing Leistritz compounding extruders, customers can use them on existing HP extruders, officials said. The ZSE Maxx, which will be commercialized in March, will be priced the same as the HP.
The ZSE Maxx comes in screw diameters of 27-135 millimeters.
Thummert echoed a common theme at K, when he said short runs are more common for compounders these days. ``Everything is done just like a pit stop on a Formula One race car,'' he said.
Leistritz Extrusionstechnik is based in Nuernberg, Germany. Its U.S. unit, American Leistritz Extruder Corp., is in Somerville, N.J.