Pressed for time: An innovative approach to an elaborate upgrade with limited downtime spells savings for a Canadian manufacturer
A wall in the lobby of Packaging Technologies Inc.'s (PTI) Concord, Ont. facility is adorned with awards that honour the manufacturer of corrugated packaging and point-of-purchase displays with excellence in packaging and printing. For 20 years, the company has been helping its customers with their creative needs - from concept to the finished product. In order to maintain its award-winning status, the company has to maintain the crown jewel of its printing operation - an eight-colour Uteco Jade 815 CI Flexo printing press. The press prints on paper substrate, and allows PTI to produce very highly visible printing on the corrugated packaging and displays that it manufactures. However, after more than a decade of production, key parts on the press were starting to wear out, and the company worried that downtime associated with equipment failure and repair would prevent it from maintaining the high standards of work and service that its customers have grown to expect over the last 20 years.
"We were having difficulty maintaining our operating parameters," explains John Franciosa, president and CEO of PTI. "It just wasn't performing to our standards."
The machine was in good mechanical shape, so the company elected to upgrade the drives and the electronics - everything from the PLC, HMI, controls, drives and more.
The challenge here was how to complete an upgrade of this size without interfering with production. PTI turned to Leading Edge Automation, a Mississauga, Ont.-based systems integrator and a provider of variable speed drive, motion control and automation solutions to the industrial marketplace.
"Since it was, at the time, not financially practical to upgrade the entire press all at once due to capital cost limitations and customer delivery schedules, this had to be done in steps," explains Craig Davis, president of Leading Edge Automation. "Through careful planning and the utilization of some unused mezzanine and cabinet space, the entire upgrade was completed in two phases."
It is this careful planning and creativity that allowed the team to complete the two-phased approach with minimal downtime. In fact, 75 percent of the job was completed while PTI was in production, or on days when the press had some downtime, says Leading Edge Automation's vice-president, Robert Cappuccitti.
Phase one: Drive replacement
The press' original analog DC drives were failing periodically, resulting in substantial losses in production while repairs were made or replacements were shipped and installed, explains Davis. To make matters worse, troubleshooting these drives was difficult, as there were no board level schematics to refer to, he adds.
Replacing these drives was a priority; however, the production schedule for the press did not allow for any downtime in the foreseeable future.
"The drives needed to be replaced to ensure reliability, but there was no possibility of interfering with production," explains Davis.
As it turns out, there was just enough space at the end of the existing lineup of enclosures to mount a new drive cabinet.
"This had the added benefit of being in close proximity to the existing drives, so that connecting the motors to the new drives would be quite simple," says Davis.
Leading Edge designed and built the enclosure using drives from the SSD Drives 590+ DRV digital DC drive family from motion and control technologies and systems manufacturer Parker. The cabinet was put in place one week prior to the scheduled shutdown in January 2007.
"The way we laid out the system was to build a new drive panel that we added onto the existing panels. This allowed us to keep them running while we got as much of the retrofit as we could in place," says Cappuccitti.
"The press was turned over to us at noon [on] Friday. The old drives were removed and replaced with a Parker SSD LINK rack and accessories," explains Davis. "The LINK rack communicates via fibre optic cables with LINK techboxes mounted on each of the 590+ drives. The program in the rack and drives interfaced through the I/O cards to the existing PLC. No changes were made to the PLC program or wiring. The motors were connected to the new drives, which were then commissioned. The press was back in full production the following Tuesday morning."
This approach allowed them to complete phase one with less than two days of interruption in production.
Phase two: PLC, controls, wireless, HMI
The drive upgrade got PTI through busy times without any costly downtime, but a well running drive system is only partly responsible for producing a high quality finished product. The print deck control system is the key ingredient, as it ensures that the ink is accurately applied onto the moving substrate.
As Davis describes: "The PLC was obsolete and failing periodically. It was difficult to work on, especially the communications with the HMI and handsets used for setting up the print. The 32 servo amplifiers controlling the eight print decks were failing in increasing numbers. Whenever one of the print decks jammed, the servos would lose calibration and a technician had to be called in [to] reset the positioning system."
Upgrading the print deck control system was important, but since it was such an elaborate upgrade, it would put the press out of commission for a long period of time. Therefore, there had been no attempt to schedule it. Then came the recession, and with it a serious decline in production. That is when Leading Edge was given the green light to proceed with the second phase.
Phase two involved upgrading the PLC, controls, the HMI and converting to wireless. Typically an upgrade of this magnitude would take three to four weeks, says Cappuccitti. Leading Edge was given just two weeks of downtime.
"Even when things are slow, you still have to produce. So we minimized the downtime," Franciosa says.
To complete this in only a two-week window of downtime, careful planning and precise timing was needed.
First, the new PLC - an Allen-Bradley ControlLogix controller - was installed to co-ordinate the operations between the drive system, the stepper system that replaced the old servo system, the new HMI and the new WiFi handsets. An Ethernet switch connected all of these subsystems together. As Davis recalls, "At nearly 1,000 I/O points, we had to work quickly and accurately to make the change."
A panel was installed in its own NEMA 12 air conditioned enclosure in a spot on the mezzanine near the old controllers a few weeks before the scheduled two-week shutdown.
Each print deck is controlled by a single ACR9000 motion controller that communicates to the main PLC over Ethernet. Each ACR9000 has a dedicated interface to six Parker EAC stepper drives that in turn control the movement of six Parker HV-343 stepper motors. Accuracy is to within one micron for each of the decks' four print and anilox cylinder axes, explains Davis.
Leading Edge developed a communications driver to allow the ACR9000 controllers to become gateways to the rest of the system for the next piece of equipment - the WiFi handset.
The original handsets were functional, but had some shortcomings - they were not wireless. They had a cord that needed to be plugged into the machine, requiring the operators to be in close proximity to the print deck they were working on in order to make adjustments. Also, being proprietary, replacements were quite expensive, and lead times were lengthy, Davis explains.
Given the circumstances, wireless was the best option to give the operators flexibility. Though wireless is becoming more common in industrial applications, using a wireless handset for precision control on a retrofitted machine in a printing environment is not commonplace, which made the task challenging for Leading Edge, especially given their time constraints.
"There were a few challenges," explains Cappuccitti. "The first [was] maintaining a strong signal in an industrial plant and around the press steel structure. We overcame this [by] moving our receiver to different locations until we found the optimum location. Also, finding a handset manufacturer to work with us that had a device that could handle this kind of wear and tear [was a challenge]."
After some digging into the wireless marketplace, Leading Edge partnered with QSI Corporation from Salt Lake City, Utah. (The company was recently acquired by Beijer Electronics.)
"QSI proved themselves to be a strong ally, from assisting in the customization of the keypad, right through to providing us with technical support while commissioning the control system software, which we developed for the application," says Davis.
"The other main issue," Cappuccitti explains, "was allowing the response from the wireless handset to our controllers and back to our motors to be fast enough. Our programmer, Ralph Tang, developed our own code to communicate between the handset and motion controllers, while allowing for the response we needed."
The final piece of equipment in this upgrade was the main operator's HMI - a Parker CTC 15-inch HPX PowerStation. The HMI allows the operator to set up and monitor the entire printing press. The recipe manager stores valuable setup information by customer/product number. It also remembers where the side lay adjustments were for each print cylinder, saving material and time when a particular order is run again.
The user administration features offer six user levels of security. Every possible adjustment, switch or button can be assigned a specific user level, making certain that special calibration and maintenance features are made by only those authorized users.
Historical trending keeps a record of all production and downtimes to track productivity and changes in the machine's operational characteristics, possibly signalling mechanical wear or some other maintenance issue.
"By using the WiFi handset and the various pages on the HMI, the operator very quickly gets a clear picture of the machine's operation. The operator can make handset adjustments and see the changes on the HMI in real time," explains Davis.
In addition, remote support is established with a VPN or any standard Internet connection, giving support staff the ability to monitor and change any program in any device in the entire control system.
After the upgrade
Reliability is a huge benefit following the installation.
"Before, we were down with components failing, and since we've installed it, we haven't experienced any appreciable downtime at all," says Franciosa.
Another benefit, he says, is a reduction in startup time. "We are able to get to the operating parameters much faster. Because of the sensitivity of the equipment now, we're able to preset and obtain the operating starting point much faster."
And as far as throughput goes, he estimates that they've experienced a five to 10 percent improvement on an overall production level.
Another benefit is servicing the upgraded system. Leading Edge removed the OEM black box technology and replaced it with updated, readily available product that the customer could source for themselves in the future without being tied to a certain company.
"That is what our goal is when we design our systems - that the product is readily available and that once it is up and running it can be maintained by in-house maintenance personnel," explains Cappuccitti.
The addition of wireless to the printing operation has proven to be a big asset on the plant floor.
"When the press was turned back over to production, the first noticeable change was the location the operators chose to stand [in] while setting up," explains Davis. "They were no longer tied to being in close proximity to the print decks. To set the initial impression (the amount of ink across the printed web), they took their usual places by each print deck. But after that, they would move down to the inspection station to fine tune the lateral and longitudinal registration. They found it much simpler and faster to set up a job, saving time and scrap."
Franciosa agrees. "It's a lot more flexible for our operators to handle the operation of the equipment, and gives them a chance to be more intuitive with the machine, because they're freer to move around with the wireless handset as opposed to before being tied in...So now with the wireless, they're able to be a little closer to the operation and make sure that everything is running smoothly."
Thanks to the innovative approach and technologies used to upgrade the company's eight-colour Uteco Jade 815 CI Flexo printing press, PTI is on the road to maintaining its status as an award-winning company. The manufacturer has recently been nominated for a 2011 Excellence in Flexography Award - a competition held by the Flexographic Technical Association that honours excellence in high graphic flexo printing in North America.
Whether or not PTI will be adding another plaque to its wall of awards, both PTI and Leading Edge are pleased with the outcome of the upgrade, and they are especially happy that it was all done in a small window of downtime with very little impact on production.
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