Field Reports: Keeping an eye on quality

Vision system removes potato strip defects with three times the accuracy of previous sorters.

By using Optyx sorters from Key Technology, Frigemo was able to accurately remove defects while keeping acceptable product out of the reject stream. The reject stream typically contains less than three percent good product. Source: Key Technology.

Employees at Frigemo, a Swiss processor of frozen vegetables and potato products, keep an eye on quality at all times. And, their dedication has paid off. McCain Foods, the exclusive supplier of french fries to McDonald's worldwide, licensed Frigemo to produce french fries under the McCain brand. The company also proudly boasts that it has earned a 58% share of the Swiss french fry market.

In an effort to keep customers happy and further increase market share, the company strives to ensure that final product quality meets high specifications. In 2004, the processor installed its first Optyx vision inspection system from Key Technology, which automatically removes defects and foreign material from the product stream. Now, Frigemo has a total of four sorters on its production lines-two handle potato products and two handle vegetables.

To satisfy the demands of each application. Optyx can be equipped with high-performance color, monochromatic and visible infrared cameras as well as Key's Raptor laser technology. The 24-in. wide Optyx 3000 Series sorters and the 48-in. wide Optyx 6000 Series sorters handle up to 20,000 and 40,000 lbs. per hour, respectively.

As product passes through the sorter, it is launched off the end of the belt for in-air viewing. Using proprietary image processing technology, the sorter analyzes the images, comparing each object to accept/reject standards. When defective product is found, the system activates one or more air jets to remove the defect from the product stream.

"The precision of Optyx is a real asset for us," says Urban Reifler, plant manager at Frigemo's Weinfelden plant, which produces frozen potato products. "Compared to the sorter we previously had on the potato strip line, our defect removal accuracy is at least three times better. We're able to focus the sorter to precisely identify the kinds of defects we want to reject."

Frigemo selected an Optyx 6455 for its potato strip line. With four top-mounted color cameras, the sorter detects and removes defects with black and green spots and remaining peel. This new sorter, installed in 2005, replaced a sorter with monochromatic cameras that could not recognize green spots as accurately as color cameras.

And while rejecting defects is a key measure of success, minimizing the removal of acceptable product is also crucial. "Key was willing to give us specific guarantees for the performance of the sorter," says Reifler. "For example, they guaranteed that less than ten percent of the product in the reject stream would be good product. In fact, it's been less than three percent. By fine-tuning the system, we can improve our yield."

For the vegetable processing lines that handle carrots, peas, green beans and other products, Frigemo installed Optyx 3755 sorters to replace manual inspection.

Peas and green beans often arrive with the green stems, leaves, pods and knuckles. Optyx identifies and removes this same-color foreign material with its shape recognition capability, while brown blemished and other color variations are easily detected and removed with color recognition.

But is it the Optyx 3355 at Frigemo that handles the most challenging application. On one line, Frigemo produces a sticky shredded potato product that is very difficult to spread. For this line, Key designed an Iso-Flo vibratory conveyor that spreads the product evenly as it enters the sorter and customized the transport belt within Optyx to assure product would not stick. This allowed Frigemo to automate what had previously required manual inspection.

"By eliminating hand sorting, Optyx gave us very rapid payback," says Reifler.

For more information:

Anita Funk, Key Technology, 509-529-2161;

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