October 2019

48 n FOOD AND BEVERAGE October 2019 www.drivesncontrols.com Morrisons’ robots pack 66,000 tonnes of potatoes a year A t its fresh produce depot in Rushden, Northamptonshire, the supermarket Morrisons has installed what are thought to be Europe’s first single-pick potato-packing cells. Each of the two robotic pick-and-place cells can handle more than 75 packs of potatoes – each weighing 0.5–2.5kg – every minute, and load them one at a time into crates, in a choice of presentation formats. Designed to improve product handling, minimise waste and enhance the presentation of pre-packed potatoes for the 11 million people who shop at Morrisons each week, the robots load the vertical form fill and seal (VFFS) and flow-wrap bags gently into retail crates. According to Morrisons’ site manager, Andy Day, the cells orientate the packs quicker than any human being, and the robot arms “never miss a beat”. The installation, which forms part of a warehouse-wide investment in efficiency improvements, has resulted in a 90% reduction in labour requirements. It is expected to handle around 66,000 tonnes of potatoes every year. The UniPaker pick-and-place cell was engineered by Brillopak in collaboration with the Morrisons team. The cells incorporate high-payload Omron delta robots. Working in parallel, the robotic spider arms load individual packs of potatoes into crates in set patterns with programmed orientations. They can achieve this with a degree of dexterity and rotation that would not be possible using a conventional layer-based automated handling system. Mechatronic hand The robots use special end-effector grippers that can handle a wide range of pack formats. The end-effectors surround each pack in a similar way to a glove. This allows them to accommodate a variety of different sizes, weights and pack lumps – Morrisons uses more than 14 different pack formats during the course of a typical season – without having to swap the tooling. According to Day, the end-effectors have more than proved their capability. “With the level of air that’s in potato bags, it was hard to conceive that a robot hand could load crates at such speed without popping or piercing the bag and damaging product,” he explains. “Previously, pierced bags has been one of the downsides to using grippers on automated case loading systems,” adds Brillopak director, David Jahn. “Additionally, when layer-picking grippers or bomb-bay doors release potatoes into trays, they are typically dropped in a haphazard way above each tray in order for the tooling to have space to open. Not only does this damage the product, but the presentation is quite hit and miss. “Suctioning polybags of heavier potatoes with varied shapes is equally challenging,” he continues. “Because it’s not a smooth surface, bags frequently sag and drop onto the packing conveyor, causing the packing line to stop. These frequent line stops have a significant impact on line efficiency and ultimately bottom-line profit.” Rather than making the end-effectors from stainless steel, which would have added to the weight being lifted repeatedly, Brillopak used soft food-grade materials as the basis for the grippers. Delta dexterity Clean, empty crates are fed automatically into each cell by two Brillopak Crate DeStaker systems. Rumble conveyors settle the packs and deliver them in single file to the robotic cells, ready for automated case loading. Each of the four-arm delta robots used in the Morrison cells has a payload of 5kg, and includes a head that can rotate. With a reach of 1,130mm – 30% more than similar sized Morrisons has turned to robots to help it stack packs of potatoes quickly and neatly into crates ready for display in its supermarkets. A special glove-like end-effector picks the packs without piercing them. Four case-loading lines at Morrison’s Rushden facility pack more than 66,000 tonnes of potatoes annually for the supermarket’s customers