A customer who is a premier manufacturer in the metals industry came to us hoping to increase productivity and decrease downtime. The company markets strips made of innovative copper alloys, serving the electronics industry and other demanding markets that require the highest quality copper-based alloy strip available. This customer was experiencing downtime with its multi-strip traverse spool winding line related to its 20-year-old, obsolete General Electric control system. In addition to downtime, the line had never run at its max speed due to the loss of tension during the wind and unwind process. The inconsistent tension through the slitting section compromised the integrity of the splice causing quality control concerns.
In the steel industry, if your metal converting process is compromised, losing a roll of steel due to poor quality is an expensive consequence. With the mounting downtime and quality concerns, the company decided a major overhaul to the traverse winding line was needed. The company’s plant maintenance manager was tasked with successful completion of this project on a very aggressive timeline. Production needed to be back up and running before depleting the company’s built-up inventory. This required the entire custom mechanical and controls system retrofit be completed in just 3 weeks, which required seamless planning and execution.
Having hired Electronic Drives and Controls, Inc. (EDC) for smaller controls-related projects, the customer trusted EDC’s expertise to meet the company’s goals for the project. “EDC exceeded our expectations by having the line back up and running in just two weeks. We are all over the place with technology – Siemens, Rockwell and General Electric. EDC’s team has been great to work with because they really understand and can troubleshoot a wide variety of systems,” said the plant maintenance manager. “They are very professional onsite and always provide great documentation post-project. In addition to that, EDC’s team has always worked with us to complete projects within very tight time frames.”
“Results have been excellent,” he continued. “With the increase in running speed, we have nearly doubled the output. We always had the capability of running at a higher speed, but we could never achieve that speed because we could not control the tension enough – that was always the problem. We have realized a 40% increase in productivity since project completion.”
In a recent interview, Chuck Dillard, vice president of EDC, shared some of the ins and outs of the project and gave us insight on the success.
How did this project come about?
Chuck: “Several years ago, the customer was referred to us through one of our other customers that builds machinery. We soon started doing retrofits on what they had for traverse winding controls. Over the years, we have retrofitted six Ruesch Sidewinders into their production line. Last year, after they were experiencing persistent problems with tension control, they decided it was time to update the entire line.”
How exactly did EDC update the customer’s traverse winding line?
Chuck: “For traversing, we converted the hydraulic cylinder technology into electric linear actuators using servo motors with ball screw drive technology to achieve high thrust forces while maintaining the ability to produce repeatable, programmable motion. We also replaced all the variable speed drives in their cabinets and their PLC using Siemens S-120 vector, S-120 servo and S7-1500 for the PLC. For the operator interface, we used a Siemens Comfort Panel touchscreen human machine interface (HMI). We created a custom mechanical design, so they could very easily pull out the hydraulic cylinders and put in this electric actuator. The new electrically powered system was able to provide thousands of pounds of thrust with the linear actuator and then we interfaced it with the traverse winder controllers that we had upgraded a while back.”
Going from hydraulic cylinders to electric actuators, how does that impact the overall picture, and why did you want to do that?
Chuck: “Hydraulics are not nearly as efficient as an electric motorized system. Electric linear actuator systems use power as it is needed for traversing, in comparison to needing to have a big hydraulic power unit running at all times. Hydraulics are also very messy; their oil leakage causes the surrounding floors to be very slippery which is a big safety hazard. They are constant maintenance, from regular cleaning to more in-depth maintenance requirements. The electric servo gives the ability for more flexible, precise, and reliable control to follow the exact command for the traverse position requirements.”
How has operation of the equipment changed?
Chuck: “The customer has benefited greatly from an operational standpoint as a result of this upgrade. In the past, they had tension issues and had to slowly increase the speed. It made it hard for the management to give directions to run the line at a higher speed because the operators would run into issues and lose control of the line, leading to bad product that costs a lot in waste and scrap. During a run, they start with several master rolls. They run a master roll, then they have to splice a new one in. They can have 8 welds per traverse-wound reel. It’s important to maintain really good tension during the time they are stopping to make the weld and starting after the weld for the traverse wind to keep its integrity. Now, the tension issues have been resolved and they can just hit a start button and the line ramps right up to 600 feet per minute maintaining tension on all of the dancers.”
What were the results of the retrofit?
Chuck: “The customer’s average running speed prior to this project was 350 feet per minute – and even then, they were nervous to run the system at full speed with the risk of failure. Now they are regularly running at 600 fpm and are capable of running up to 850 fpm on a 1” strip which is a pretty impressive response on a traverse winding setup. With the increase in the overall speed of their line and the ability to now hold tension during acceleration and deceleration, they are realizing a 40% increase in productivity with much better quality.”
What contributed to the success of the overall project?
Chuck: “Winding and unwinding applications are certainly in our wheelhouse. We specialize in tension control and have engineered, built and retrofitted controls for hundreds of pay-offs, take-ups, rewinds and unwinds. Proper planning, project management and execution from start to finish is critical. We handled the entire project. Therefore, we had control over coordinating all the moving parts to achieve success in the tight time frame required. After the design phase, we completed as much of the programming and build as we could at our facility. On site, we had everything lined up and ready to go. We provided electrical contracting to run cables, wires and conduits. We did the mechanical retrofit on hydraulic cylinders. We replaced all of the panels within the enclosures. We performed start-up and connected all the wiring. In two weeks, the line was up and running with a significant improvement in productivity.”
The customer’s traverse winder line upgrade has proven to be a great investment. The plant manager shared his experience working with EDC over the years saying, “EDC does what they say they’re going to do. They were able to perform this project in a very tight time frame for us. Time is critical for us – EDC worked odd and extended hours to make this happen. We do not have redundancy in equipment, so the retrofit had to be quick. EDC originally estimated the project would take seven weeks, but they were able to revise their schedule to do it in less than the three weeks we gave them to complete the project.”