Originally Published PMPN October 2003
EDITORIAL
On the Record
Machine vision systems are masters at finding defective products and packages. For instance, the Alumivision system from Micron Development Group can find pinhole defects in moving webs of blister foil. Uhlmann Packaging's VisioNIR can find incorrect product composition as well as empty capsules, without touching product. And the latest smart cameras from DVT, Cognex, and others help packagers put eyes anywhere along the line, easily and economically.
But can machine vision find the cause of defects? Not always, explains Jim Dechman, president of Monitoring Technology Corp. As a former production manager for Procter & Gamble, he recalls the labor needed to find the source of defects on a high-speed packaging line. "When we couldn't find the problem with our sensors, we would bring out a high-speed camera and position it to record parts of our process where we felt the trouble was. It required a couple hours of setup. Then we'd find nothing and have to position it elsewhere and spend another couple of hours. Finding the cause could take three days."
Dechman says that he wasn't the only packaging professional in search of an easy-to-use troubleshooting tool. "Every line produces off-quality product once in a while. And the machines are moving so quickly, motion is often a blur."
When Dechman joined Monitoring Technology Corp. in 1996, the firm was just starting to offer digital video for recording processes. Typical applications involved positioning 10–20 digital cameras along a moving web, say, for paper machine operations. Dechman was interested in using the technology to help packagers, but he knew that placing cameras at every location where a packaging process could break down would be an "enormous economic commitment."
In addition, he says, "Packaging folks need flexibility—something they can roll around the line. They also need simple systems that can be set up easily and quickly."
When Monitoring Technology came up with 20/20 Hindsight, Dechman knew that it would work for packaging. "The system is designed for easy use on the line 24 hours a day," he says. "It is another set of eyes that a production or maintenance person can use to quickly determine the cause of jams or off-quality production. They just point the camera at the problem area and walk away. After the equipment jams, they scroll back through the video and replay the jam in slow motion. No wiring is required."
Dechman explains that 20/20 Hindsight takes 60 pictures a second, recording each photo separately. It holds the last nine hours of video for reviewing purposes, and users can index to a single photo.
But 20/20 Hindsight isn't meant to replace machine vision, says Dechman. He says the two can work in concert to keep quality in check. He cites a project in which a packaging line's sensor was rejecting about 25% of product. The firm placed a 20/20 Hindsight system near the sensor to find the trouble. Operators found that due to timing problems in the line's rejection system, the sensor was rejecting the wrong 25% of product, kicking out good product and keeping bad product.
Dechman will be speaking about Procter & Gamble's use of 20/20 Hindsight at Pack Expo Las Vegas, along with Chris Froah, a packaging engineer for Procter & Gamble. The system will also be on display in 15 booths at the show, including R. A. Jones' and SIG's booths.
Jams and rejects may be at minimum on your lines, and your sensors may be telling you all you need to know. But a picture of your process could be worth thousands in rejected products.
Daphne Allen , Editor
Copyright ©2003 Pharmaceutical & Medical Packaging News
