Specific AC and DC motor and drive solutions can be applied dependent on the type of end plastic product being produced as well as the type and size of the extruder. Motor types typically used include AC induction (enclosed or laminated frame designs), DC, servo or permanent magnet.
Variable speed drives are used for precise motor control and increased energy efficiency, as well as for environmental and cost reasons. Drives also provide dynamic torque limit for protection of the extrusion screw without speed or position feedback devices, resulting in lower initial investment and installation costs and higher operational reliabilit.
Various types of downstream machinery may be present to facilitate necessary cooling, take-off and/or other discrete handling of the extruded material, such as cut-to-length, slitting, stacking, coiling, etc. These are in general typical drive applications requiring drive performance characteristics ranging from speed or torque regulation to simple motor control.
The melt pump is fed by a speed-regulated, pressure-controlled extruder which provides precise control of the molten plastic output flow, optimizing the consistency of the flow delivery rate.
Precise tension control is vital for plastic film processing. The superior speed regulation of ABB drives maintains the tension within the established limits and the fast, accurate drive-to-drive line speed communication provides precise synchronization of take-off roll sets.
Film must be wound under constant tension, requiring torque regulation of the winder motor, which must continually adapt to ever-changing roll diameters. This can be achieved either by using an ABB drive with winder software or integrating a separate PLC into the control system.