New drives and motors help breathe new life into 30-yr old extrusion line

By: 
April 29, 2011

If money were no object, then most of us would opt to buy new. But money matters, plenty, so sometimes we need to reuse and refurbish. That was the case for flexible plastic films processor/converter Amgraph, which had a 75-feet (23m) long Black-Clawson two-station extrusion laminator it wanted to upgrade to meet new customer requirements.

Like any company, Amgraph (Versaille, CT) had a choice to make with its laminating machine. It could spend millions on a new machine, do nothing to its 30-yr old unit and settle for lower productivity, or retrofit the equipment. Amgraph's management opted for retrofitting, and planned to upgrade the analog control system with the use of Siemens motors, Sinamics S120 digital drives and newer control systems.

As a result of the retrofit, Amgraph can now produce a wider variety of coated plastic and foil flexible food packages, cut material expenditures and improve throughput, while boosting productivity.

The upgrade was handled by a Siemens solutions partner company, Circonix (Ringwood, NJ). "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," explained Circonix VP 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 reckoned that by upgrading the machine's analog drives and discrete controls to new Siemens motors and Sinamics S120 digital drives, Amgraph could accommodate new materials, process packaging with thicker coatings, achieve uptime of 95% or better, and increase throughput by 20% or more.

Circonix engineers retrofitted the extruder's four analog drives with Siemens 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 a primer coater, and served as pull stations for the machine, which was driven by Siemens motors and drives. These modifications allowed the machine to work in closed-loop tension control mode.

By changing values on the human/machine interface (HMI) and PLC, Amgraph's production manager, David Rand, could now 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."

It looks like the new motors, upgraded digital drives and new controls also will increase the extrusion machine's uptime, throughput and productivity. "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. We should have some firm numbers in the next few months." Rand says the retrofit already has increased throughput by up to 20%, depending on the product line.

As Amgraph's operators were familiar with third-party HMI and PLC technology, Circonix needed to interface the Sinamics S120 drives with these third-party systems.

 

 

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