September 2014 Roundtable on Web Guiding & Tension Control
Director of Sales
General Manager, Guiding Systems
Q: What are some new developments of your company that fall under this category?
Breen: One of the more exciting recent developments in tension control for us has been the SteadyWeb5 digital tension controller and the associated Wi-Fi communications features that we recently added to the product. For converters or printers who choose the web-server option, the tension, tension set-point and other control parameters can be accessed by any Wi-Fi-enabled device. Customers can control who has access to the controller through the software.
In addition to the remote access capability, customers can download the tension controller setup and tuning parameters for individual jobs onto a USB for sharing with additional SteadyWeb5 controllers, or to add to a spreadsheet for documenting and comparing the setup parameters between different jobs. This can be useful as a diagnostic tool or for reference when optimizing controller tuning.
What we find driving the popularity of this controller with web converters and flexible packaging printers is the fact that even though it is packed with slick digital features – like the job settings transfer via USB memory stick – the device has retained some of the useful analog user-interface attributes – like the big round adjustment dial – that made controllers from previous generations easy for machine operators to use.
Closed-loop controllers of any type that are active in a fast-moving production environment can seem complicated and may take the average machine operator a long time to master. However, the color, backlit, graphic LCD display and that rotating knob on the front of the SteadyWeb5 make it less intimidating for operators than the more traditional soft-key buttons and text-only displays that are prevalent in digital tension controls in the industry.
Schmidt: We are continuously developing new web-guiding sensors to detect materials and communicate with our customers’ data collection needs. A recent development is our DSE-17 digital edge/center guide sensor. This sensor is digital as opposed to analog, which simply means when it scans looking for the edge of the web, it is not looking for a certain preset light level to determine the guide or point, but simply a transition from light to dark. This allows us to lock onto edge of webs that have varying opacity or non-uniform density.
A side benefit of this sensor is that it detects contamination in the sensor field of view, either in the atmosphere or on the sensor view glass, and ignore it or compensate to prevent an undesired guide point shift. This sensor is designed with a wide field of view, allowing for web center guiding without repositioning the sensors or, depending on your web width, you may be able to center guide your web with one sensor. This is one of many recent new sensor developments from the Fife brand at Maxcess.
Jonozzo: We are focused on expanding our product line’s ability to communicate with a customer’s overall machine control or plant industrial network. Specifically, enhancing our HMI’s external interface capability and simultaneously providing backward compatibility so customers can retain the other elements of their existing web guide system. The enhanced HMI will add features such as smart alarms, a range of industrial networking options and expand sensor options, all while maintaining our brand’s ease of use and “plug-and-play” functionality. We recognize the investment customers have made in SimPlex systems and want to meet their plant process needs while minimizing the necessary investment.
Q: What can be improved upon when a converter is looking for better web guiding/ tension control?
Schmidt: A better understanding of web guiding accuracy, what components affect accuracy and how to ensure you have the most accurate system available today. Also, system gain, sensor sampling rate, actuator design, guide structure geometry, etc.
Jonozzo: First and foremost, web guiding must be properly applied to maximize its effectiveness and results across a wide range of webs. In many instances, we encounter poor web path geometry and the guiding deployed just will not deliver the desired results. Next, ensure a system is robustly designed and routinely maintained to deliver the desired accuracy, repeatability, and reliability for continuous operation. All web guide systems employ some combination of electronic, mechanical, hydraulic, and/or pneumatic devices that require some periodic attention to provide optimal performance. Lastly, improving the guide point accuracy, so that the material webs are positioned precisely just prior to a critical application is paramount. In some instances, web guiding needs to be physically moved closer to a key process in order to offer the maximum control.
Breen: Loss of color-to-color registration while running at speed, splicing or changing speed; inconsistent repeat length; and slack web which can cause web breaks and wrap-ups around driven rolls are perhaps the most obvious consequences of inadequate tension control on a web press.
Others include deformation of web due to stretching or wrinkling; variation of coating thickness; unwind or rewind core crushing; reduction of machine speed to accommodate web handling problems or any of the problems above; hard rolls; soft rolls; telescoping rolls; excessive waste of web material; and the inability to run a wide range of web thickness’, widths and materials.
Many of these problems are simply accepted as normal and are not attributed to inadequate control of web tension. However, printers and converters experiencing such trouble and recognizing the relationship can improve efficiency and profits by employing tension control.
In the case of converters who are already using functioning tension-control equipment, they may not need to upgrade to newer equipment until their existing devices fail, which in some cases takes ten, twenty or even thirty years. We have customers who return older tension controllers for repair that have been working reliably on converting or coating lines for the last three decades. We let the customer decide whether they want us to repair the old unit, or whether it might be time to invest in an upgrade to the newer more compact digital controllers that are easier for operators to master.
Q: What kinds of trends/technologies is the web guiding/ tension control sector seeing?
Jonozzo: Customers continue to demand products and systems that require less operator intervention and involvement while providing a higher level of intelligence to the overall machine’s automation. Web guide controls are becoming more integrated in the operator’s machine control, less a standalone system, and more integrated into the overall process control.
Breen: In line with the environmental movement that’s driving industry to develop packaging solutions that leave a smaller carbon footprint in society, we see the trend toward thinner flexible substrates continuing. We also expect the efforts of materials processors, converters and printers to lower production waste to continue.
As a manufacturer of electronic controls, we are deploying rapidly advancing digital processing technology. Because of smaller IC’s (integrated circuits) with larger processing density, we also see computing power concentrating into smaller packages just as we see in the consumer electronics world.
This CPU compression translates into more features, smarter devices and easier-to-use interfaces in upcoming generations of the sensing, display, measurement and control equipment that machine designers build into their web presses and converting machinery. So, newer, faster, waste-cutting production devices for the flexible packaging industry will be a continuing trend from the tension control manufacturers too.
Schmidt: We are seeing more requests for completely integrated guide systems that have the control panel and sensor(s) pre-mounted to the guide structure, which mounts directly to the customers pre-existing mounting holes. This allows the user to quickly and easily install the system, and with the Fife one-button automatic setup, you can be up and running quickly.
Q: What are your customers requesting more of these days?
Breen: Although tension measurement and control equipment plays a vital role in the production quality aspect of flexible packaging converting and web printing, it’s a process variable that our customers want to work invisibly, without them having to worry about how or why it’s working. The greatest compliment we can hear from customers is that they’re not even aware that their tension control equipment is doing anything. They mount it to the machine; and it sits there and works. That’s how it should be.
Customers also expect fast deliveries, fast and friendly customer service and tech support, and reliable equipment that is easy to order, install and use.
Technology-wise, customers are requesting more features in their tension controllers and lower prices. Features such as adaptive tuning for applications with rapid accelerations or decelerations, digital calibration, and color GUI displays are now common and are appreciated by customers.
When a new tension controller with more advanced technology, a larger feature set and a smaller footprint becomes available on the market, and at a reasonable price, users can often justify the retirement of an older controller on a cost/benefit basis.
Also, certain segments of the industry, like the bag makers, would appreciate a very low-cost, unwind tension control system that doesn’t necessarily have to use direct tension-sensing technology. We started to address this need with the EasyWeb torque controller this past year.
Jonozzo: Cost-effective solutions that provide ease of use and minimal setup while requiring as little incremental operator intervention as possible. In essence, web guiding products that are smarter, provide more information and improve reliability. The bottom line is to decrease a converter’s operating cost.
Q: Why is web guiding/tension control such an important part of the converting process?
Jonozzo: In many cases today without properly applied web guiding, the printing and converting industry’s end products could not possibly be manufactured to the exacting specifications required. Further, web guiding is an instrumental tool for the typical converting operation to achieve the throughput, yield and waste-reduction goals necessary to achieve profitable results and remain competitive. Without web guiding, line speeds decrease significantly, material shape problems dramatically affect end product quality, and scrap increases. For a relatively small investment, the opportunity to ensure greater productivity for a printing press or slitter is a fairly simple decision.