The VisionPak™ form/fill/seal machine from CP Packaging (www.cppac.com) is a six-axis machine for packaging deli-style and other types of meat products. Roll-fed forming stock is unwound and fed into the machine. The film is thermoformed into cavities into which sliced meat is inserted. Lidding material from a second unwind station is then heat-sealed to the formed cavities to finish the packs.
Designed “from a blank sheet of paper,” according to Ray Buchko Jr., vice president of operations at CP Packaging, the VisionPak makes especially good use of controls components from Bosch Rexroth Corp. (www.boschrexroth-us.com), including advanced pneumatics, IndraDrive Mi integrated servo motor/drive units, and IndraMotion MLC controller.
“On this type of machine the forming Web is usually pulled through by clips attached to a chain drive, one chain on the left and one on the right,” says Buchko. “A single motor, plus a drive shaft and gears, drives the two chains. But torsional pressure on the shaft causes the chains to stretch, and because they don’t stretch evenly you get uneven wear leading to uneven machine operation.
“In the VisionPak machine there’s no mechanical drive shaft and no chains. Instead of a chain drive, we have a belt drive, one belt on each side, and each is driven by a servo motor. These two motors are synchronized by a master encoder so that both belts are driven with the exact same amount of torque each cycle.”
All six servo motors are washdown-rated IndraDrive MI units, which combine a traditional servo motor and drive into a single compact unit. This design reduces the size volume by more than 50 percent compared to traditional servo drives using a separate motor and drive. With smaller integrated components, the size and expense of the control cabinet and the overall machine footprint are significantly reduced.
One feature that appealed to CP Packaging is the IndraDrive Mi’s innovative “daisy chain” cabling design, which significantly reduces the amount of cable connections. Only a single cable containing both power and communication is needed, so the drives are easy to connect without a lot of wiring. “With the IndraDrive MI system, not only did we eliminate the need for a remote cabinet, we reduced the control panel space by 50 to 60 percent and realized a 30 percent cost savings overall,” says Buchko. “By daisy-chaining the servos, we reduced our cabling, which helped improve sanitation, cut the potential for downtime, and lowered our cabling costs. Now we can run our cables better to protect them from the washdown process, and by getting rid of the remote cabinet, a crew can install the machine in a matter of hours instead of days.”
Not only is the control cabinet mounted within the machine frame, it swings out on hinges to make cleaning simpler and more effective.
The other area where the VisionPak shows advanced technology is in its pneumatics. Web-feed systems on vacuum-packaging machines like this typically require some type of film accumulation system or tensioning dancer bars because film can’t be pulled directly off the roll and straight into the machine without some slack in the film. But CP was able to eliminate the need for mechanical dancer bars by using Rexroth ED05 electro-pneumatic proportional valves to regulate the tension on the wind and unwind rollers and film-sealing bar.
“This is the first form/fill/seal machine in the industry to do that,” says Buchko. “Not only does it eliminate mechanical components, which reduces costs and potential downtime, it improves sanitation by minimizing the ability for any surface debris on the dancer bars to contact the film.”
Rexroth also provided HF03-LG valve manifolds with Profibus interface to control the air cylinders for the forming, sealing, evacuation, and cutting. The HF03 valve series is a modular valve manifold system providing high flow in a compact package with low power consumption.
Buchko also credits automation distributor CMA/Flodyne/Hydradyne (www.flodyne.com) for its use of Rexroth’s IndraWorks uniform software suite in crucial machine programming that gives the VisionPak its advanced functionality.
At Dietz & Watson, a Philadelphia-based provider of sliced luncheon meats and cheeses that is the first to install the VisionPak, vice president of engineering John Schoenfellinger says the new machine has been a welcome addition.
“The innovative motor and drive system pulls film smoothly through the machine,” says Schoenfellinger. “They also moved the drive motors out of the washdown area and gave the control cabinet an innovative hinge design that swings out of the way for total access to the machine. And while comparable machines require a lot of rollers and tensioning dancer arms for film feed, ours uses pneumatics to replace the dancer, giving us faster changeovers and better control of the film during operation. We’re seeing at least a 10 percent improvement in changeover speed. Plus we had the machine running within 24 hours of delivery.”
