Extruder gets tubular with IIoT

June 14, 2017
Teel Plastics handles complex recipes and reduces errors with help from Kepware's KEPServerEX software with IoT Gateway

Regular experts know a lot, but veteran experts know how much they still have to learn. Such is the case with Teel Plastics Inc. in Baraboo, Wis., which has been specializing in custom, extruded plastic tubing and profiles for more than 60 years, but still seeks user input and external know-how in new areas to keep on improving.

The company's products are used in geothermal pipes, solar film cores, co-extruding products, healthcare tubing, film cores, converting cores, filtration components, industrial tubing, consumer products and for many other purposes. Because they're used in so many applications and industries, Teel has added numerous engineered characteristics to its tubes, such as specialized layers, coatings, finishes and other physical characteristics to meet customer requirements.

“On any day, a consumer is likely to interact with at least one product we’ve had a hand in making,” says Owen Gwynne, senior programmer at Teel. “We view our customers as partners and invite them to work collaboratively during the design and development of their projects. As such, we’ve been able to complete products quicker and innovate to keep up with demands and anticipate future needs."

Not surprisingly, all this innovation, collaboration and variety in so many applications has produced thousands of recipes and procedures, which Teel's skilled managers, technicians and operators must preserve and recall to maintain the high-quality tubing their customers trust them to produce. Fortunately, the firm's professionals are also expert enough to know when to enlist help with recipe management, network connectivity and production scalability. As a result, they recently sought assistance from Kepware and its IoT Gateway for KEPServerEX software on 10 of their 50 production lines. Kepware is a software development business of PTC.    

Go tubing, avoid errors

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The basic extrusion process on Teel's production lines begins with screw machines and equipment that generate internal pressure and friction to form and melt raw plastic pellets into liquid. The plastic passes over a metal shaft suspended in the stream to create its ever-present hole, is squeezed into a vacuum tank to prevent it from collapsing, and moves into water or air tanks to harden before cutting. These continuous production lines vary between 40 feet and 100 feet (Figure 1). 

Each line requires a custom recipe for every product, and these recipes include different material inputs, equipment, heating devices, and other variables. Recipes can change several times in one day, and ones that haven’t been used in months can resurface when new orders come in. Many components on the lines are controlled by PLCs and other controls, mainly from Rockwell Automation, Siemens and Red Lion, which manage and optimize temperature, pressure, speed, air and vacuum, heaters and screw speeds.

"In the past, the lines were mechanically connected and coordinated, and operators would go down each line, and adjust settings manually," says Gwynne. "This meant a lot of resetting for new products several times per shift. We were dealing with five or six different machines and components per line, and 30-40 different adjustments were needed either manually or through a PLC."

However, all these shifting variables could quickly cause situations in which human error deviated the recipes. These deviations inspired Teel Plastics to find a solution that would allow operators to control all pieces electronically and reduce human error.

“There are many variables that go into a single recipe, and our employees interact with, memorize and apply multiple recipes during a single shift,” explains Gwynne. "There are a lot of different reasons for errors: employees are moving too quickly, it’s a recipe they're unfamiliar with, or they’ve arrived in the middle of a production run. However, what seems like a miniscule issue can lead to our products having flaws or to manufacturing downtime. We knew there had to be a way to minimize some of these errors.”

Left hand knows right

To gain the connectivity, data access and scalability they needed, Teel's executives recently developed a strategy that would allow the machines and equipment on their extruding lines to link up via the Internet of Things (IoT) and capitalize on its benefits. They evaluated several IoT offerings, and found many that could address one or a few of their needs, such as business, protocol or standards functions, but not all of their requirements. Teel's search was further complicated by the fact that many of its lines and machines are custom built, which means they needed a system that could speaking to their range of PLCs from several suppliers. 

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Initially, Teel considered developing an IoT solution in-house, but eventually found that Kepware’s IoT Gateway for KEPServerEX provided a most seamless, reliable, and scalable way to control all their essential components through one web interface. Gwynne adds that Kepware's software serves as a bridge between many of these individual PLCs and controls, which maintain customized, web-based interfaces that can be displayed on PCs anywhere, and allow operators to use web-based inputs to their equipment. To maintain the interoperability granted by Kepware's software, Teel doesn't use a proprietary Ethernet protocol on its network, and interacts via the Internet's standard hypertext transfer protocol (HTTP).

"IoT Gateway begins with Java code and a representational state transfer (RESTful) server, which convert PLC commands," explains Gwynne. "IoT is okay with the web-based controls we built because they're sent via Java, which is web-based, too, and gives us the ability to communicate with the huge variety of equipment we have. It was also nice to build our application using IoT Gateway for KEPServerEX because it could handle other devices besides our on-line work." (Figure 2) 

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Alex Herbert, manager of strategic accounts at Kepware, adds that Kepware released KEPServerEX version 6.1 in April, and adds it includes new drivers, added IIoT connectivity, configuration API updates, and support for complex data via OPC-UA for more PLC types. "Kepware and KEPServerEX have always sought to fit into existing architectures, and provide quicker access to data for better decisions," says Herbert. "Now, with IoT Gateway, we can get data flowing through more interfaces and the cloud to help users even more."

In addition to its extruders, Teel performs data acquisition and archiving, operations and material management. Kepware's software was able to assist all of these interactions and tasks. "Kepware helps us interact with the PLCs, but it covers a range of other equipment, too," says Gwynne. "We handle many devices ourselves, but we put on Kepware where we can."

Gwynne reports that Teel's newly web-based and IoT-enabled extrusion lines are also helping its operators input and extract more accurate information, and making it easier for rookies to learn and run their equipment. "We're able to put experienced operators to work on the lines because Kepware's system guides them and holds their hands better," adds Gwynne. "Also, because we're on the web with Internet protocol (IP), we can interact with the lines internally and externally, do remote log ins, and allow supervisors and managers to check production."     

Herbert adds, "Other users can use KEPServerEX and IoT Gateway to achieve benefits like Teel has by defining their own specific challenges and use cases, and determining what's needed to make their operations and businesses run more effectively. "IoT can seem daunting at first—how can you connect a whole enterprise? However, you can just start out small and simple. It only takes a few minutes to connect KEPServerEX, and with IoT Gateway, it's easy to add applications, and show data to staff and customers. We have users that previously took manual data samples every 30 minutes and then made changes to their equipment, and now they're gathering data every few seconds and controlling their applications iteratively."

Gain ground, report results

Following its integration of KEPServerEX, Teel determined that its operators could send pre-saved recipes with more than 20 parameters from a web interface to IoT Gateway, which then distributes instructions to the machines on the line. This is much more efficient than Teel's former manual process, and enabled it to reduce setup times by 30%. Plus, by providing device connectivity to multiple PLCs, Teel adds it dramatically reduced its risk due to human error.

"Our operators have been able to simplify the reconfigurations and adjustments they have to make to fulfill their changing recipes because IoT Gateway for KEPServerEX connects to multiple devices, sends all settings needed to the lines, and translates them for the different PLCs in their equipment," says Gwynne. “By incorporating IoT throughout our shop floor, we’ve been able to take tasks that previously required memorization and 30 to 40 clicks, and bring them down to just one click of a button." 

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Since implementing IoT Gateway, Teel's staff has also increased their visibility into granular details of their manufacturing process. This in-depth plant floor data enables the company's engineers to test different variables, which further cuts downtime. Also, by monitoring different aspects of production, such as room temperature, and making slight adjustments, its operators and managers can make its recipes more efficient.

Likewise, seamlessly aggregating data on indicators, such as humidity or parts wear, into a central database enables operators to monitor equipment for predictive maintenance. This database also lets Teel's leaders make more informed decisions about recipes, so the company can increase output and maintain higher quality at the same time.

"Because the IoT Gateway accepts commands from the web interface, and spreads temperature or other data to an array of PLCs, these upgraded connections let our extruder lines and machines run much more quickly," adds Gwynne. "For example, prior to implementing the IoT Gateway, one line was completing 18 units a minute, and now it's outputting 35 units a minute—nearly doubling its capacity."

In addition, IoT Gateway also gives Teel personnel peace of mind. Operators no longer have to memorize recipes, which allows them to complete tasks with greater confidence. Also, Gwynne reports that shift changes have never been smoother because incoming operators can easily pick up right where previous operators left off.

Finally, Teel's customers can now see detailed data that proves their requests are being met to their exact specifications. This visibility has increased their comfort with standard requests, and has even led many to expand their requests.

“While we were initially focused on eliminating human error in our manufacturing process, the IoT Gateway is empowering us to do much more,” adds Gwynne. “Our employees are a huge asset to our company’s success, and this new technology empowers them in their positions and allows them to do a better job. Also, we’re able to produce many more units per minute, and can reduce our waste from erroneous products. All in all, we’re providing our customers with more product at a higher quality, and they're taking notice.”

Though the firm has only implemented IoT Gateway for KEPServerEX on 10 of its 50 extrusion lines so far, Gwynne adds that Teel will likely expand its use of the software to more lines and equipment soon. "Kepware has already met many of our needs, but we may begin to look at functions we can build on top of it," says Gwynne.    

About the Author

Jim Montague | Executive Editor

Jim Montague is executive editor of Control.