Basis weight control is critical to the operation of paper machines.
The basis weight control valve must be able to respond to small input changes of <1%. In the vast majority of applications, this requirement is met with either a pulsed input gear motor or a stepper motor actuator with a complex electronic controls interface.
The problem is the high-cost of maintenance for these specialized actuators. Many mills keep dedicated onsite spares due to long lead times for spare parts. Also, there is often a lack of in-house expertise to troubleshoot and repair these actuators, which can result in machine downtime.
