At 30 years old and approximately 75-feet long, the Black-Clawson two-station Extrusion Laminator dominates Amgraph’s production floor like a dinosaur lining up at a bone yard. As customer requirements surpassed the capabilities of this aging behemoth, the Versaille, Conn., company, which supplies flexible packaging systems for the food industry, had several choices. It could spend millions on a new machine, settle for lower productivity and product diversity or retrofit the equipment for the 21st century. Senior Management decided to prepare their 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.
Engineers retrofitted the extruder’s four existing analog drives with motors and Sinamics S120 drives, while adding four load cells inline, and a new Fulton Machinery dancer to the machine’s two unwind spindles. These modifications allowed the machine to work in closed-loop tension control.
Siemens Solutions Partner, Circonix, located in Ringwood, N.J., knew that by upgrading the machine’s analog drives and discrete controls Amgraph could accommodate new materials, manufacture packages with thicker coatings, achieve uptime of 95% or better, and increase throughput by 20% or more.
“Initially, the machine had four different motors with analog drives and controls, each with their own wiring harness and relay logic,” explained Circonix Vice President of Engineering Andrew 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 retrofitted the Extruder’s four existing analog drives with motors and Sinamics S120 drives, while adding four load cells inline, and a new Fulton Machinery dancer to the machine’s two unwind spindles. Also, two Vetaphone 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 the motors and drives. These modifications allowed the machine to work in closed-loop tension control mode. By changing values on the HMI and PLC, Amgraph’s Production Manager, David Rand, could now 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,” said Rand. “Our initial trials have been successful.”
The high bandwidth of the digital drives improved speed regulation and response, both of which are key to improving tension control. Amgraph set aggressive goals of 95% uptime for the retrofitted extrusion machine.
In addition to increasing uptime and the number of products the machine can handle, Rand said the retrofit has increased throughput by up to 20%, depending on the product line. “We’ve definitely increased production speeds,” he said.
Amgraph was familiar with third-party HMI and PLC technology, which meant Circonix needed to interface the drives with third-party systems. The engineers used Siemens’ STARTER drive engineering/commissioning software to deliver the project 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,” said Alaya. “With Siemens DC bus line up, all the drives fit in one 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 in July of 2008, and six months later, installed and commissioned the retrofits.
Siemens Industry, Inc., Drive Technologies — Motion Control
www.usa.siemens.com/MotionControl
Filed Under: Machine tool industry + subtractive manufacturing, Mechanical, Motion control • motor controls
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