Downtime Resolved and Operator Control Simplified
“We are very happy with our recent control system upgrade to the packing list envelope line. The equipment operates much better than it used to. EDC’s engineering team communicated with us extensively during the project to really understand our needs. This included streamlining the controls with advanced technology to simplify operator control making it user-friendly and easy for operators. Now it takes just two weeks to train a new operator before they can run the line on their own, a much quicker learning curve to bring new employees up to speed.”
Vergilio Jacinto, ADM Production Manager – First Shift
BACKGROUND
Founded in 1964, ADM Corporation is the industry leader in the manufacturing and supply of high-quality pressure sensitive envelopes and packaging and shipping products worldwide. ADM puts quality first in all aspects of the business including strict quality control standards; whether it is investing in new equipment or keeping current equipment in peak operating condition, ADM is proactive.
PROBLEM
Downtime for one of ADM’s envelope converting lines for its pressure sensitive envelopes had become problematic and costly. The equipment’s legacy Indramat drive and control system was causing the increased downtime. Finding replacement parts for the obsolete system was difficult at best.
SOLUTION
EDC is an expert in control and drive systems for converting, coating and laminating processes and equipment. EDC has worked with ADM for 24 years upgrading equipment and providing 24/7 responsive service when needed. “If we have issues with our equipment, we always try to fix the problem with our in-house resources first. If we can’t resolve the problem in-house, we call EDC. We have tried another less expensive resource and always come back to EDC. They are very responsive, know what they are doing and work well with our people,” said Susan Mota, VP of Operations.
One of the keys to success for any upgrade/retrofit project is understanding the process and thoroughly evaluating what current drive and control components should be replaced and what should stay for the optimal solution. In this application, the web unwinding system feeding material to two DC drive-controlled dancers controlling the web tension before the laminating process was maintaining proper tension and providing reliable web transport. EDC determined that section should be left alone.
In order to address downtime and restore the envelope converting machine’s typical production rates, EDC recommended retrofitting the envelope converting equipment with a state-of-the-art PLC-based motion control system with new motors and drives. In addition, EDC recommended replacing the operator’s cumbersome variety of push buttons, knobs, dials and meter controls with a new simplified user-friendly touch screen HMI. Some improved mechanical modifications to the clamp section and the implementation of a heater lane robotic set-up helped to add to product quality and increase OEE (Overall Equipment Effectiveness).
The new components included:
- Siemens S7-1500 PLC
- Siemens 1FT7 motors for high-performance motion control applications with integrated DC brakes
- Siemens S120 drive for the three main motion axes
- AMCI Stepper Drive
- 15” Siemens Comfort Panel for the HMI
EDC retrofitted three legacy Indramat TDM servo drive motors with three new state-of-the-art Siemens 1FT7 servo motors with integrated DC brakes, and integrated DRIVE-CLiQ with a single-turn absolute position encoder. The new motors have an integrated DC brake that gets powered on the same cable that powers the motor. The DRIVE-CLiQ system interface is an innovative, high-performance interface that supports simple data communication among the converter components. It speeds installation and commissioning while virtually eliminating wiring errors.
The servo drives need to perform a very precise coordinated motion for a quality cut. The goal was to achieve 120 cycles per minute for a 4.5” envelope. The pull roll needed to feed 4.5 inches, cut and seal, and repeat the process 120 times per minute with a 1/16th inch tolerance. The first drive controlled the pull roll (index roll) of the material – moving it forward the appropriate length. The second drive controlled a guillotine blade, and the third drive controlled the clamp. Programming the axes needed to be precise as there is potential for the two axes to collide – they need precise motion to go down and up in unison so that the clamp is holding the paper down for a stable, clean cut.
To simplify the equipment’s operator control, EDC moved a lot of the manual dials and push buttons into a user-friendly Siemens HMI touch screen monitor. For example, the old Eurotherm temperature control units with dial heating control for the side sealing bars was moved to the PLC using Watlow SSR (solid state relay) outputs for easier operator temperature control through the Siemens HMI touch screen.
Working with ADM to determine how best to streamline operator control, EDC left some of the basic start-stop selector switches, e-stop, and the e-stop reset as physical buttons. All other modes were centralized and integrated into the new HMI touch screen. Enhancements to the system were also added including recipe control and the ability to create a production report with screenshots of different production parameters and the current date easily downloaded through a USB port.
To further enhance usability, EDC worked with ADM’s staff, to make everything clear and concise for the operator to enable and disable different features of the machine as it’s running. This included registration control, table speed and other auxiliary devices operators can enable/disable and control. Verbiage for control was also adjusted to provide a clear, simple interface to the operator.
RESULTS
The control system retrofit added years of new life to the envelope converting equipment achieving production output goals while meeting ADM’s strict quality control standards. The benefits of this upgrade included:
- Improved reliability
- Reduced maintenance cost
- Expanded capabilities
- Comprehensive, efficient code for motion control
- Recipe-based seal parameter helps machine operator control complex parameters
- Total management of real-time quality-related data for accurate adjustments
- More complete operator control of weld/seal quality and consistency
- High throughput (120 cycles/minute for 4.5” envelope with a 1/16th inch tolerance)
- Fast switchover between jobs
- Substantial reduction in rejected seals and material waste
- Saved space in control cabinet with use of newer technology
- Consolidated knobs, dials and meters into a user-friendly color touch screen
ADM’s Plant Manager Gene Potts has been with the company for 29 years. Gene spoke about ADM’s long relationship with EDC. “I have been working with Chuck Dillard (VP of Engineering) from Electronic Drives and Controls for around 24 years now. He has been a reliable partner with great integrity and that means a lot to us. In addition, it is clear that EDC invests in their people – they are highly trained and professional. They understand our equipment and processes. When we need help with our equipment, they fully analyze the problem and we can trust they will recommend the best and most cost-effective solution. When we do encounter an urgent problem beyond our staff’s ability to resolve, EDC response time is swift to get us back up and running.”
