Three strategies for mixed-SKU palletizing in frozen food warehouses

For operators with steady demand for mixed-SKU pallets, a layer picking and palletizing system integrated with the ASRS can be an effective and feasible solution. Working together, the ASRS and layer picking system—connected by automated conveyors—enable efficient, fully automated mixed-layer palletizing that keeps personnel out of the freezer. 

As with any palletizing solution, the feasibility of layer picking for a particular warehouse is dependent on customer order profiles and the volume of pure mixed-layer pallets required. But remember that even if a full layer isn’t required for every mixed-SKU order, it can still be more efficient to customize a mixed-layer pallet to order requirements by swapping out some cases than it would be to build the entire pallet manually.

Swisslog has implemented layer picking solutions integrated with our Vectura pallet crane and PowerStore pallet shuttle ASRS solutions for a number of leading food manufacturers. Swisslog ProMove conveyors transport pallets to the layer picker from the ASRS where mixed-layer pallets are built and then moved outside the freezer or back into the ASRS for storage, with the entire process controlled by our SynQ software. 

While highly efficient, layer picking isn’t right for every application as it may not easily support the SKU variety customers are requesting. In this case, a light-goods shuttle system, such as the Swisslog CycloneCarrier, or mini-load crane, such as the Swisslog Tornado, can provide case storage and sequencing to support optimized manual palletizing. 

When cases are required for an order, the shuttle delivers them in the exact sequence required to pickers working just outside the freezer. Because of the efficiency of the process, product isn’t outside the freezer long enough to jeopardize quality and pickers are able to work in a much less harsh environment. Height-adjustable load holders at the picking station position the pallet or roll cage at the right height for each layer so the picker never has to bend down to place cases on the bottom layer or lift cases to build top layers, minimizing back strain and optimizing ergonomics. This solution also supports a smooth transition to fully automated palletizing as robotic palletizing modules can be added later to take the place of manual pickers.

This is the type of solution Swisslog deployed for Apetito, a European leader in frozen convenience foods that needed to modernize an aging frozen food warehouse that was unable to keep pace with growing demand. The solution deployed by Swisslog includes automated depalletizing robots that provide cases to an 18-aisle mini-load ASRS. The ASRS is connected via conveyor to the picking and shipping areas, in this case within the frozen area. The precise sequencing of cases presented to each picker by the ASRS enables orders to be fulfilled with maximum efficiency and accuracy.

Where warehouse space is limited or the volume of mixed-SKU pallets doesn't justify automation, a pick tunnel can be an effective strategy to increase the productivity of manual palletizing processes. With this approach, the ground level of selected aisles in the ASRS is designed to accommodate manual picking and palletizing. Conveyors enable the ASRS to replenish the pick tunnel on demand and remove completed pallets from the tunnel, eliminating the need for forklift operators to support palletizing. By organizing products efficiently and reducing picker travel and wait times, pick tunnels improve the efficiency and accuracy of mixed-SKU palletizing operations. Eliminating the need for forklifts in the freezer also enhances picker safety. 

Managing storage and palletizing in the deep-freeze warehouse