"We had several goals in mind for the project," says Erik Larson, project engineer. "First, we wanted to ensure that the meats were inspected with a high level of detection and a low false-reject rate. Second, we wanted the ability to match a rejected product with its specific X-ray image to allow rework of the rejected product. Finally, we wanted to find a product inspection machine that provided the basics-reliability, cleanability and ease of use."
Johnsonville kicked off the project with a six-month test using an unnamed inspection machine. This test process resulted in a higher-than-normal reject rate that came with the first X-ray scan. When rejected products were X-rayed for a second time, the results determined that only one-third of the initial rejects contained a contaminant.
"The big concern was the large number of false rejects, which leads to slower production time and profit loss," says Larson. This machine was also unable to successfully match the rejected product's computer-scanned image with the product or container as it was rejected.
The company then brought in the Eagle Pack X-ray system from Smiths Detection as well as machines from two other competitors for a side-by-side comparison. The Eagle Pack system was the clear winner. It is large enough to inspect two lanes running side-by-side through the machine. By configuring the system for dual-lane inspection, one lane could be running primary product constantly while the other lane could take the rejected product and be used as a rework lane. The X-ray system's display was modified to show only the rejected images from both lanes on the screen in a split-screen display.
Once the product is sent back through the rework lane, the Simul-Task 3.0 Image Analysis Software holds a picture of the scanned product so that the product can be retrieved from the reject bin, and the contaminated piece can be removed and replaced without affecting production.
Because it has the ability to rework rejected products through the rework conveyor lane, Johnsonville purchased several of the machines and uses them throughout the facility.
"We are impressed by the consistency and reliability in the Smiths Detection product line to detect and reject small contaminants," says Larson. "The equipment purchases continually pay for themselves as our contaminate complaints have been significantly reduced with Smiths X-ray equipment."
For more information: Art Schwinge, Smiths Detection;