ZSE 27 iMAXX Leistritz Extrusionstechnik GmbH gave this co-rotating, intermeshing twin-screw extruder for rapid in-line compounding and production of prototype sheet samples a new, user friendly redesign based on customer feedback. The machine has a length-to-diameter screw ratio of 40-1, with modular barrels and segmented screws. An LSB-26 side stuffer can be used for feeding filler or fiber.
WHAT'S NEW? PLC distributive processing control architecture: A master PLC manages the overall system, consolidates recipe management and data acquisition; and a discrete PLC controls sub-processes. Because the extruder and downstream lamination system have their own PLCs, they can operate independently or together. Also new: the unit's integrated construction. Leistritz did away with the control cabinet by putting all cables and electrical elements, including the water-cooled frequency converter, into the base frame. (The smaller, water-cooled motor is from Siemens.) The inlet, outlet and coaxial valves of the closed dual-circuit water supply are also integrated, into the supply frame. An inspection window allows monitoring of the safety coupling.
BENEFITS The PLC architecture is significant when integrating systems from multiple suppliers with different technologies. The PLC's tuning algorithm analyzes system input and corrects extruder RPM and feed rate to maintain gear pump inlet pressure at a given set point. The new design saves space, offers greater mobility and is easier to clean, but with the same high-torque and high-volume capabilities as before.
Leistritz Advanced Technologies Corp., Somerville, N.J., 908-685-2333, www.leistritz-extrusion.com
