Products - Hybrid DynaTest™

The Hybrid DynaTest measuring device has been developed to analyze dynamic behavior of a roll. Measurement information is used by Hybrid GrindControl 3D and Hybrid RollManufacturing systems.

Research and development has been carried out in co-operation with Helsinki University of Technology, Metso Corporation, AK-Tehdas and Finnish paper industry. Metso and AK-Tehdas are using their Hybrid DynaTest measuring devices in roll manufacturing.

Improvement of the runnability of a paper machine and reduction in the quality variation of a paperweb requires a control of the rolls dynamic behavior at an operating speed. Balancing machines can not provide adequate information of the rolls dynamic behavior, because measurement system determines only the state of unbalance. The Hybrid DynaTest measuring device utilizes the Hybrid multi-point algorithm.

Measurement detects phenomena resulting from the structural inaccuracies, an error motion of a bearing assembly and properties of the support structures. With an aqcuired data the dynamic behavior of a roll is finally optimized at the operating speed by either Hybrid GrindControl 3D NC-device or Hybrid RollManufacturing system.

Software consists of the routines for the measurement, analysis and numerical calculations together with an interface to provide machining information for Hybrid GrindControl 3D NC-device. Connections to the external systems such as measurement unit of a balancing machine, a control system of a drive unit and roll maintenance data systems are optional.

Hybrid DynaTest - Characteristics

Runout in any direction

• Harmonics of runout (runout spectrum)
• Runout tolerances (runout at contact point)
• Detection of quality variation of paper resulting from rolls
• Resonance vibrations at subcritical speeds
• Detection of runnability problems

• deflection compensation by 3D Grinding Technology
• 3-plane balancing with counterweights
• displacement of centre axis of mass

• geometry compensation by 3D Grinding Technology
• dynamic deformation of roundness profile
• mass compensation

• Bearing excitations and geometric errors of roller path and shaft error motion.

Mill Experience

Tero Olander, Manager, Roll Factory, Metso Paper Järvenpää, Finland (November 12, 2001):

"The backing rolls of Metso Paper for the broad and top speed coating machines are inspected with Hybrid DynaTest™ roll dynamics measuring device. Precision backing rolls compliance with the requirements pertaining dynamic deformations and vibrations are difficult to perceive during the manufacturing process without Hybrid DynaTest™."

"Hybrid DynaTest™ has assisted us to clarify and improve an ability of our manufacturing process to produce quality. Now we know, how different rolls act dynamically in the process conditions. We've been able to optimize design, manufacturing and balancing processes while the requirements have continuously arised."