Energy costs possess an ever-increasing share of manufacturing costs. For this reason, KraussMaffei Berstorff, a market specialist in machines and systems for plastics and rubber processing, is identifying ways of helping customers to reduce power consumption. For example, the company now offers its range of 36D single-screw extruders with energy-efficient, high-performance, three-phase AC motors.
As a supplier of extrusion machinery, KraussMaffei Berstorff has taken up the power-saving challenge. The starting point is always a detailed energy audit of the main energy consumers in an extruder in order to pinpoint the modules with the highest energy consumption and the greatest losses. The main areas of heat loss are the barrel of the plasticizing unit and the drive train -- the gearbox and a conventional DC motor. In response to these results, KraussMaffei Berstorff offers solutions that address these heat losses.
The company now offers -- as standard -- all the single-screw extruders in its 36D Exclusive series for PO pipe extrusion with three-phase AC motors instead of DC motors. The efficiency of AC-driven extruders is higher than the equivalent DC versions; the efficiency gain is between 5 and 12%, depending on the operating point.
Low maintenance and cleaning effort improves uptime. This in turn improves extruder productivity. A reduction in the number of wear parts, for example, no carbon brushes or collectors, makes the machines even more rugged and reliable. The AC motors also show substantially better behavior under part-load than the DC drives. One of the contributory factors here is the sharply reduced reactive current requirement.