Paper machine applications require the DC Drive to electronically synchronise axes across the machine so that line speed & tension can be varied or kept constant as required. Because reel diameters are constantly changing, the DC Drive has to control the motor under separate speed-torque conditions to ensure constant speed & paper quality. Sprint Electric Digital DC Drives can control multiple-axes using deterministic position control to provide exceptional machine performance for paper applications. Naturally regenerative, our Digital DC Drives provide energy-efficient solutions.
Paper mills use specialist machines equipped with large DC motors to produce pulp from raw material, convert pulp to paper, wind to reel and post-produce by slitting, coating, printing and packaging.
Paper Processing Applications
Paper machine applications require particularly wide speed & torque control from the Drive system. For example, winders and coilers require the DC Drive to provide constant torque over a wide speed range down to very low motor speeds or even standstill. Large diameter paper reels present high-inertia loads to the DC motor that requires high-bandwidth control from the DC Drive – as well as the ability to regenerate back to the mains. Sprint Electric Digital DC Drives are installed in hundreds of paper mills globally and provide consistent and durable performance across the entire range of paper machine applications.
Sprint Electric Digital DC Drives are used in the forming, press, drying and calendar sections for unwind, rewind, traverse, and general motor control applications. DC Drives are also used in post-production applications such as grinding, folding, printing, stamping, slitting, packaging and wrapping.
WINDERS & REELERS
When the paper has been wound onto reels from the paper machine, it must be cut into sizes that suit the downstream printing process.
Re-sizing is carried out on a slitter re-winder. Paper is fed from the unwind stand, through a set of slitter knives, then driven back to a re-wind system. This process requires separate speed control and torque control to ensure consistency of paper wrap during the wind-up process. Sprint Electric Digital DC Drives provide exceptional-bandwidth for high inertia loads as well as full regenerative capabilities providing energy efficient quick stop capabilities.