Having decades of experience helping clients in the metals industry, our engineering team knows the slitting line process inside-out and are experts in automation and control system technology specific to the industry. Typically, when we start with one slitting line retrofit, the success of that first project leads to retrofits of their Metals converting equipment at multiple plants for the same client across the country.
Having implemented control systems for both new slitting lines and retrofitting a countless variety of older slitting lines, EDC has developed deep domain expertise to help our clients optimize production. Because of the complex and nuanced processes for this type of production equipment, there is no universal cookie cutter solution. Each new and retrofit project needs to be developed according to the manufacturers’ unique conditions and production goals.
EDC collaborates with plant managers and operators to evaluate the slitting line from loading the coil and set-up procedure through to the slitting and recoil process to tailor the optimal solution to improve production performance. Although each project is unique, there are 7 common problems we have encountered through the years which are triggers to consider a control system upgrade. In no particular order, here is our list of common problems and examples of solutions we deploy to solve these challenges:
Tension Problems Create Quality Control Issues
For slitting lines, tension is an important variable. If the tension is not controlled properly, material defects become a problem. Often the material is too taut going in and out of the slitter resulting in a host of quality issues from burring to scratching of the material. A slitting line makes a much better-quality cut at controlled low tension at the entry and little or no tension at the exit of a slitting head. To achieve optimal cut quality, adding a loop going in and a loop coming out of the slitter can solve the tension problem. If you have an entry and exit loop currently and are experiencing quality issues, the control system should be evaluated for potential adjustments. No matter what your problem EDC can help to improve your Precision width tolerances.
- EDC’s Entry Loop Solution – To solve for taut entry tension problems, EDC can implement controls to provide an entry loop section to the machine allowing for low tension slitter entry, which will assist in making a better split off. We can also add a sonic sensor above the loop for feedback to the control system to adjust the speed of the motors to maintain optimal loop position.
- EDC’s Existing Exit Loop Improvement Solution – In many of the facilities that we have visited, an operator is manually manipulating the exit loop which is an art and a nuanced talent. As many longtime operators are approaching retirement, the knowledge and know-how is hard to replace. If an operator is not experienced or not paying attention, either they might run the take up too fast creating a taut web on the exit, or they might run it too slow causing the slit metal to become scraped up at the bottom of the pit. Leveraging the control system, EDC can provide a loop position feedback on the exit loop, eliminating the need for the operator to have to constantly make adjustments.
- EDC’s No Exit Loop Solution – If you do not have an exit loop you would have to dig a pit that’s 30 feet deep which is not practical in many cases. Although not optimal, EDC can provide a controls solution to operate in a slip core configuration. Another solution can be the implementation of Traverse winding.
Slow Slitting Line Setup
Traditionally, slitting line setup is not a quick process and can hamper your ability to meet production goals. Setting up automated recipe management can significantly reduce setup time. Operators can easily select the appropriate recipe from a user-friendly touch screen, significantly reducing the setup process and improving product consistency between shifts.
Extended Downtime for E-Stop
There are cases when an e-stop is required during an operational anomaly. When this happens too quickly and is not controlled properly, it can cause extended recovery time and possible damage to the line.
EDC can incorporate a coordinated, rapid stop utilizing safe torque-off, web break sensors, and control algorithms to maintain web integrity, saving valuable minutes in setup recovery.
Difficulty Hiring Operators
The National Association of Manufacturers’ 1st quarter of 2021 survey of manufacturers report ranked the inability to attract and retain talent second place behind the rise in raw material goods on the list of top challenges. It was noted by 65.8% of those completing the survey. Previously, the labor issue was the primary concern in 11 of the past 13 quarters prior to this release. With approximately one quarter of the manufacturing workforce being age 55 or older, the skilled labor shortages are very real and not likely to improve anytime soon.
If you are too reliant on aging operators who have been with your company for a long time, it’s time to simplify running your manufacturing lines by leverage automation technology. Automating previously manual tasks (i.e., automating loop tension) will enable a less skilled operator to quickly complete training and smoothly transition into taking ownership of running the line. Automating allows new operators to achieve the same or better results of the retiring operator. Modern user-friendly touchscreen operator interfaces with built-in troubleshooting diagnostics will also help attract, train, and retain the younger generation of workers who have grown up with intuitive smartphones and computers.
Bearing Wear in the Slitter Head
Bearings in the slitter head will start to wear over time, causing loss of precision and other operational difficulties and quality degradation. To help our clients resolve this issue, EDC works with slitter manufacturers to facilitate an upgrade of the mechanical portion of the slitter to bring it back to original tolerances needed for precise slitting.
Edge Trim Control
All slitting lines produce some scrap due to edge trim. Whether you are using a scrap baller or a scrap winder to collect your edge trim, proper control of your edge trim motor can limit the amount of scrap produced. Limiting the amount of scrap adds to your bottom-line profitability. EDC can address this often-overlooked inefficiency by fine-tuning the motor and controls in your scrap winding section.
Legacy Control System
Many of the first six problems we have discussed could be related to operating your equipment with legacy controls. Slitting lines are true work horses; the physical equipment well exceeds the operating life of the control systems that run the equipment.
Running your slitting line on a legacy control system retired by the original manufacturer is like dancing with the devil – you never know when you will get burned. The longer the control system has been retired by a controls manufacturer, the higher your chances of extended downtime. If you have resorted to looking for parts on eBay, it is only a matter of time before unexpected downtime will translate into a costly emergency.
Legacy control examples include Allen Bradley’s PLC5, SLC-500, Siemens’ S5 and S7-300, GE 90-30, as well as many other obsolete AC and DC drives.
Evaluating a retrofit is highly recommended and you may be surprised at how the advancement in technology can offset the cost, yielding a favorable return on investment. In one case study, our client reported a 40% improvement in productivity after replacing an outdated General Electric control system. EDC can help you evaluate and map out the highest value retrofit.