Session: 16-02-01: Poster Session: NSF Research Experience for Undergraduates (REU), NSF Posters

Paper Number: 99642

99642 - Close-Loop Control of a Roll-to-Roll Gravure Printing Process 

Roll to roll (R2R) Gravure Printing transfers ink from an ink tray to depressions in a printing roller and from depressions to a moving web substrate. During the R2R Gravure Printing process, a doctor blade scrapes off any excess ink that is left on the printing roller. Once the ink is in only the depressions of the roller, it stamps the pattern of ink onto a web substrate under the pressure of an impression roller. This type of printing process has been developed to produce flexible electronic devices including thin-film transistors, wireless cyclic voltammetry tags, a carbon nanotube-based active matrix for tactile sensors, and wearable electrochemical biosensors, as it produces high-resolution patterns at high precision and with high throughput. In the state of the art of this printing process, unsynchronized speeds between different rollers, including impression roller, depression roller, and the rollers on the upstream and downstream of the Gravure printhead, create defects in the designed patterns and cause poor product quality. In detail, the setup consists of two rollers that are upstream and feed the substrate through the gravure cylinder and impression roller and then around two more rollers downstream that collects the final product. The rollers that function to feed and collect the substrate before and after going through the gravure cylinder and impression roller are connected to a separate motor that is not synchronized to the motor that powers the gravure cylinder. To resolve this issue, we design a closed-loop feedback control system for the gravure roller. An encoder will be installed onto the gravure roller to measure and control the roller’s speed corresponding to the web moving speed. To ensure accurate and precise speed and position reading of the gravure roller, the encoder needs to be mounted to the roller in high positioning accuracy and precision.  We design and print an adaptor to secure the encoder into place in trivial and tolerant calibration errors. Through this encoder, the gravure roller speed is measured in real-time using transfer functions in LabView and then is controlled for synchronization with the other rollers. Once the synchronization has been completed, the system will be tested to observe the printing quality. After testing, an overall analysis of the printer setup will be evaluated and improved to optimize the printing productivity. The printer is theoretically analyzed in SOLIDWORKS, and from there the printing process can be observed and any potential issues can be identified and fixed to optimize the printing process. The desired results for this project are to control the misalignment between the web speed and the roller speed. 

Presenting Author: Ryan Packer UMass Amherst

Presenting Author Biography: Ryan Packer is working toward his B.S. and M.S. in Mechanical Engineering at the University of Massachusetts Amherst. Ryan is a member of the Commonwealth Honors College and a club chairman. His research areas include roll-to-roll printing and flexible electronics manufacturing.

Authors:

Ryan Packer UMass Amherst
Jingyang Yan UMass Amherst
Xian Du UMass Amherst