More X-ray vision
Most baked foods and snacks are packaged in plastic films or paperboard cartons, materials essentially transparent to metal detectors. Those baked and sold in foil pans or packaged in metalized films present a different problem, one requiring another sort of electromagnetic radiation: X-rays.
In the past, slow inspection speeds tended to work against use of X-ray technology. Modern systems, however, solve such limitations. For example, Mekitec USA offers the Midmeki, a mid-range unit in its Meki line, which operates efficiently at conveyor speeds nearing 6.5 ft per second, according to Rick Clayton, general manager and global service manager, Mekitec USA.
He described a recent installation where the baker added a Midmeki to look at products baked and packaged in aluminum foil tins and other products too large to pass through the existing metal detector. With a detection zone 16- by 8-in., it could handle the large trays of brownies and loaf cakes. “With in-foil scanning, no manual intervention was necessary to prepare goods for inspection,” Mr. Clayton observed.
The compact units have on-screen displays that pinpoint the exact location of the contaminants in the product. This helps operators take corrective action more quickly. All reject images are saved for later analysis and traceability, an important aspect of any inline safety management program.
Because X-rays provide an inside look at every product, they exceed human inspection capabilities. They can find broken cookies or cracked pizza crusts within packages and count objects to verify coverage or fill.
And this applies to all products that pass through the system. Mr. McGhie compared this method to manual inspection. “Samples measured [manually] can represent just a small fraction of the products made on the line, whereas the inline inspection system measures 100% of the products made and records statistics for each measurement every two minutes or for a period set by the user,” he said. “The system generates reports based on shift, day, week and month, with date and time stamps, providing results for all products inspected.”
To give users a head start, Heat and Control’s new Ishida IX-EN and IX-Gn Series X-ray (IX) line of inspection systems provides patented Genetic Algorithm (GA) image processing. Systems come with many standard GA settings for a range of products and possible foreign bodies already stored in the machines. Also available is an optional fail-safe system that prevents a contaminated product reaching the consumer in the event of a power outage or breakdown, helping to minimize the potential for costly recalls.
Read on for practical advice for buyers of inline safety equipment.
