In digital sorting, to optimize performance, the system must be designed specifically for the products being sorted and properly sized for the application. It must also be well maintained by the user, to prevent diminishing performance. 

In digital sorting, performance is typically measured as a ‘defect removal rate’ as well as a ‘good-to-bad ratio.’ Sophisticated sorters typically achieve defect removal rates of 90 to 99 percent or higher. The good-to-bad ratio often ranges from 1:4 to 1:10 and is sometimes as high as 1:50 or 1:100. These results depend on the nature of the product, the effectiveness of the sorter’s infeed and the pitch of the sorter’s ejection system, among other things.

Challenges from A to Z

The primary challenge associated with sorting wet potato products comes from the splatter that can obstruct sensor windows, light sources and backgrounds, which hurts the sorter’s performance. For whole potato sorters, the biggest sanitation challenge comes from dirt. Here, high-performing mechanical pre-cleaning solutions and the sorter’s mechanical design help to overcome the challenge.

In the case of Key Technology, for sorting whole potatoes, the Herbert Oculus sorters were recently added to the Key sorting product range. Inspecting tubers with 360° vision, Key’s Herbert Oculus sorters detect color defects, diseases and surface abnormalities. This includes skin discoloration, green and dark colors, bumps and notches, mechanical damage, common scab, cracks and black dot. Oculus is ideal for sorting pre-peeled whole potatoes, either unwashed or washed, in or immediately following storage to eliminate defects and FM and identify the dimensional profile of incoming raw whole potatoes to improve downstream processes. For potato strip sorting, Key’s VERYX® continues to lead the industry with the most advanced features. As the world’s only sorter that is able to inspect product entirely in-air with both top- and bottom-mounted cameras and laser sensors, VERYX achieves sustainable all-sided surface inspection to detect and remove more FM and defects.

“For whole potatoes, the 360° roller system on the Oculus sorter achieves 20 percent more potato surface inspection to improve sort efficiencies and offers gentler handling than traditional cascade sorters. Compared to other 360° sorters, Oculus is the only sorter that can reach capacities of up to 80 metric tons per hour,” says Karel Van Velthoven, Advanced Inspection Systems Product Marketing manager at Key Technology.

“For potato strips, VERYX is our best-selling digital sorter. Featuring sustainable all-sided surface inspection, unique multi-sensor Pixel Fusion™ and the highest resolution cameras and laser sensors on a digital sorter, VERYX removes more FM and the right amount of product defects to make grade while virtually eliminating false rejects to maximize yield,” Van Velthoven adds.

You can read the rest of this article in your complimentary e-copy of the March-April Issue of Potato Processing International magazine, which you can access by clicking here.