Key Technology high-capacity sorting system for spinach

Key Technology has developed a sorting system for fresh spinach. The integrated system includes an Iso-Flo fines removal shaker or dewatering shaker together with an acceleration belt and Manta digital sorter to inspect fresh spinach and other leafy greens such as cut cabbage, cos and iceberg lettuce. It is suitable for sorting fresh product at receiving, after cutting, or after washing and drying.

In tests, the sorting system removed 100% of the foreign material (FM), while achieving a false reject rate of 0.5%. The system inspects up to 5.9 tons/h of spinach, 5.5 tons/h of romaine or iceberg lettuce and 22.7 tons/h of cut cabbage.

When located at receiving or after cutting, the first step in the process is a three-deck fines removal shaker. If the system is located after washing and drying, a dewatering shaker is the first step. Next, an acceleration belt spreads and stabilises product for optimal presentation to the sorter.

The sorter is equipped with three top- and two bottom-mounted Vis/IR (visible infrared) cameras and two fluorescence-sensing lasers. The cameras recognise colour, size and shape to detect leaf defects including mechanical damage, decay, wilting and colour defects. The lasers identify differing levels of chlorophyll to detect FM such as insects, larvae, weeds and leaves. When sorting chopped cabbage, cos or iceberg lettuce, the laser is also configured to detect and reject core.