New controls give aging extrusion lamination line new life

At 30 years old and approximately 75-feet long, the Black-Clawson two-station Extrusion Laminator dominates Amgraph’s Versaille, CT production floor. To say that it was no longer on top of its game would be putting it mildly. But management decided to prepare their outdated equipment for the needs of tomorrow by upgrading the analog control system to high-efficiency Siemens motors, Sinamics S120 digital drives, and newer control systems. As a result of the retrofit, Amgraph

• can now use the 30-year-old system to produce a wider variety of coated plastic and foil flexible food packages
• has cut material expenditures, and
• has improved throughput while boosting productivity.

Andrew Alaya, vice president of engineering at Siemens Solutions Partner Circonix, knew that by upgrading the machine’s analog drives and discrete controls to the latest Siemens motors and Sinamics S120 digital drives, Amgraph could accommodate new materials, manufacture packages with thicker coatings, achieve uptime of 95 percent or better, and increase throughput by 20 percent or more. “Initially, the machine had four different motors with analog drives and controls, each with their own wiring harness and relay logic, which really made the machines a challenge to maintain,” says Alaya. “Only one of the sections was capable of tension control, which forced Amgraph to operate the extrusion machine in draw mode. This meant that the machine could only handle certain types of coatings without breaking the web and going down. Improving that uptime through better tension control was the main goal of the project.”

Circonix engineers decided to retrofit the extruder’s four existing analog drives with Siemens motors and Sinamics S120 drives, while adding four load cells inline plus a new Fulton Machinery  dancer to the machine’s two unwind spindles. Also, two Vetaphone surface treaters were added inline as part of the retrofit. These effectively eliminated the need for the primer coater and served as pull stations for the machine, which were driven by Siemens motors and drives. These modifications allowed the machine to work in closed-loop tension control mode. A change in the values on the HMI and PLC enabled Amgraph production manager David Rand to precisely control the speed and thickness of the web, turn various systems such as treaters, laminators, and tension control systems on or off, and apply either thinner coatings to package materials without worrying about additional web breaks and downtime, or thicker coatings to meet special customer needs.

“Now that we have more control of the system, we’re looking at replacing thicker films that we used to purchase from other vendors with extruded materials we make ourselves, which saves us money,” says Amgraph’s Rand. “Our initial trials have been successful.”

Better uptime and throughput

The new motors, upgraded digital drives and new controls also increased the extrusion machine’s uptime, throughput, and productivity. The high bandwidth of the Sinamics S120 digital drives allows for improved speed regulation and faster response, both of which are key to improving tension control. Amgraph set aggressive goals of 95 percent uptime for the retrofitted extrusion machine. “We’ve had some success since the machine was installed in January,” says Amgraph’s Rand. “We spent a few months fine-tuning operations, but recently we’re starting to see uptime benefits.”

In addition to increasing uptime and the number of products the machine can handle, Rand says the retrofit has increased throughput by up to 20 percent, depending on the product line. “We’ve definitely increased production speeds,” he said. “We’re happy where we are now, but we still have opportunities to improve throughput.”

Retrofitting large production machinery like Amgraph’s Black-Clawson extrusion laminator machine rarely comes in as scheduled because changing a machine from discrete analog to digital control systems with the latest energy-saving AC induction motors presents significant electronic and mechanical engineering challenges. Customers may also want to use specific equipment providers for certain systems. In this case, Amgraph was familiar with third-party HMI and PLC technology, which meant Circonix needed to interface the Sinamics S120 drives with third-party systems. However, thanks to Circonix’s close partnership with Siemens as an official Siemens Solutions Provider, Siemens’ STARTER drive engineering/commissioning software, and the easy integration of the Sinamics S120 drives using the electronic name plate capabilities of Drive-Cliq for the motors and drive components, the project was delivered to Amgraph on time and within budget.

“We used Profibus to tie the drives together and an SST module in the PLC to talk to the Siemens drives,” Alaya explains. “It was easy to meet Amgraph’s development schedule. With Siemens DC bus line up, all the drives fit in a single cabinet that was smaller than the space of one of the previous motor control systems. We were able to eliminate the wiring mess and relay logic that came with the older analog controls, which significantly simplified maintenance and troubleshooting for the customer while improving performance and uptime.”

Circonix started engineering development for the system and, just six months later, installed and commissioned the retrofits.

“We gave them a pretty intense schedule,” says Amgraph’s Rand. “What’s remarkable about this project is that it was done on-time. We have some machines that came in before we did this project and they’re still not up and running.”