rewinding

What are Terminal Web Guides?

Terminal web guides are devices used at the entry and exit of a roll-to-roll machine to appropriately align the web to the desired cross machine location. Entire roll of the web, on the unwind/rewind stand, is moved along the cross-machine direction for the proper alignment.

The process of manufacturing products using roll-to-roll (R2R) methods involves unwinding of thin, flexible material in rolled form into machinery for processing and winding of the processed material into a roll. This paper describes modeling and control of a rotating turret winder in the rewind section of a R2R printing press. Governing equations for web speed and web tension within the rewind section are described by taking into consideration the motion of the rotating turret winder. Data from production runs of an industrial R2R printing press are analyzed to determine web behavior during a wound roll change sequence accomplished by the rotating turret. Model simulations are conducted and data from these simulations are compared with typical data from production runs. The key challenges associated with controlling web speed and web tension in a rewind section containing a rotating turret winder are discussed along with recommendations for machine and control design to achieve improved regulation of process parameters.

In this paper, winding issues in an industrial R2R printing press using a rotating turret winder are investigated by utilizing a new mathematical model and data are collected during production runs. Production data and simulation results from the developed model are analyzed to identify the causes for tension disturbances that affect winding quality. Model simulations are conducted by incorporating production data as inputs to the model to gather insights into the effect of dynamic behavior of the rotating turret winder on winding web tension. The developed model captures the various dynamic events associated with the roll change operation with a rotating turret winder. Measured data are provided to support the results of this work in improving winding tension regulation during the roll change operation. The new model together with the analysis and recommendations provides a good framework for the development of model-based tension control schemes that can further improve winding tension regulation performance, and thereby improves wound roll quality.