- May 01, 2010, Edited by Claudia Hine, Managing Editor
A30-year-old, 75-ft-long Black Clawson two-station extrusion laminator dominates the production floor at Amgraph Packaging. As customer requirements surpassed the capabilities of this behemoth workhorse, Amgraph, which supplies flexible packaging for the food industry, had several choices. It could spend millions on a new machine, settle for the lower productivity and product diversity that come with aging equipment, or retrofit the extrusion laminator for the 21st century.
Instead of scrapping their investment, Amgraph's senior management decided to prepare their equipment for the needs of tomorrow by upgrading its analog control system to high-efficiency Siemens motors, Sinamics S120 digital drives, and newer control systems.
As a result of the retrofit, Amgraph now can produce a wider variety of coated film and foil flexible food packages, cut material expenditures, and improve throughput, while boosting productivity.
Improved Web Tension
Initially, the machine had four different motors with analog drives and controls, each with their own wiring harness and relay logic, making the machines a challenge to maintain. 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 handle only 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.
Engineers at Circonix Technologies, a Siemens Solutions partner, decided to retrofit the extruder's four existing analog drives with Siemens motors and Sinamics S120 drives, while adding four load cells in-line and a new Fulton Machinery dancer to the machine's two unwind spindles. Also, two Vetaphone treaters were added in-line 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.
By changing values on the HMI (human-machine interface) and PLC (programmable logic controller), David Rand, Amgraph's production manager, can control the speed and thickness of the web precisely; turn on or off various systems, such as treaters, laminators, and tension controls; 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 we used to purchase from other vendors with extruded materials we make ourselves, which saves us money,” says Rand. “Our initial trials have been successful.”
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% uptime for the retrofitted extrusion machine. “We've had some success since the machine was installed in January,” says Rand. “We spent a few months fine-tuning operations, [but] recently, we're starting to see [uptime] benefits. We should have some firm numbers in the next few months.”
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%, depending on the product line. “We've definitely increased production speeds,” he says. “We're happy where we are now, but we still have opportunities to improve throughput.”
Amgraph Packaging | 90 Versailles Rd., Versailles, CT 06383 | 860-822-2000 | www.amgraph.com
On Time, Within Budget
Retrofitting large production machinery, such as Amgraph Packaging's Black Clawson extrusion laminator, 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 also may want to use specific equipment providers for certain systems.
Because Amgraph was familiar with third-party HMI and PLC technology, Circonix Technologies had to interface the Sinamics S120 drives with third-party systems. Due to Circonix's partnership with Siemens, 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.
Profibus was used to tie the drives together, and an SST module was used in the PLC to talk to the Siemens drives. With Siemens DC bus lineup, all the drives fit in a single cabinet that was smaller than the space of one of the previous motor control systems. This upgrade simplified maintenance and troubleshooting for the customer while improving performance and uptime.
Just six months after Circonix started engineering development for the system, it installed and commissioned the retrofits. “We gave them a pretty intense schedule,” says 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.”