During the production of its potato products, Wernsing Feinkost GmbH has been using optical sorting machines to assess the quality of the potatoes for many years. For a long time, it used so-called ‘free-fall’ optical sorting machines, where bad potatoes were ejected. Since the sorting quality of the machines was not high enough, a manual inspection was always carried out by several employees. However, due to rising personnel costs, labour shortages, and increasingly stringent quality requirements, Wernsing decided that they wanted to fully automate the entire sorting process without compromising on quality.
Wernsing came to Marcelissen, a Dutch company that builds food processing and sorting machinery, and told them they currently had 12 optical sorters and 10 employees who checked the potatoes after they were categorized as “good product” by the optical sorters. The sorting quality had an accuracy of about 60%. They wanted to get the sorting quality up to more than 90% and this without any manual inspection. Marcelissen accepted this challenge and a development process followed where they placed one optical sorter in the line next to the current installation for a null measurement.
From day one, the Marcelissen sorter performed much better and they concluded that with a number of small optimizations they could halve the number of sorting machines needed and also ensure that Wernsing would not need 10 employees but only one operator.
Marcelissen installed 6 optical sorting machines including an infeed system at Wernsing Feinkost GmbH. An important factor to achieve the set requirements was not the use of the highly accurate vision software but mainly the combination of this software with the Marcelissen philosophy regarding the ejection of different potatoes. Where other suppliers try to separate the bad (read: waste) product from the good product flow, Marcelissen separate both categories.
This means that not only is there a separate exit for the bad product but also a separate exit for the good product. This means that one action is required to sort both good and bad products, which results in a minimum chance of product flow mixing (good flow and waste flow).
After a year in production, Wernsing Feinkost GmbH is still working without any manual inspection and the quality is higher than 95%. The six optical sorters are functioning to full satisfaction and even the amount of maintenance and downtime has decreased in comparison to the original situation. The cooperation has worked out well for both parties and will only be further strengthened in the coming years with other great projects stated the companies.
