Express sorting centers have huge throughput and tight timelines; wheeled warehouse cages move bundled bags and loose parcels from chutes to the loading dock, far faster than manual carrying. The core of cage selection is: run fast, carry a lot, fold empty cages back, and survive crashes.
Cage dimensions are designed around transit vehicle loads; common external size is 1100×800×1000 mm, holding dozens of bundled bags per cage. The cage has four swivel casters, two with brakes, 5–6 inch wheels, rolling smoothly on the sorting floor and tipping not when crossing speed bumps.
Make the sides a full-open or half-pull door so chute sorters place bags from the side without reaching over the cage top. Leave the top uncovered for dropping bags in from above; dense mesh at the bottom stops small parcels falling out. Choose 5 mm wire diameter, which survives hundreds of bumps a day. Add anti-collision strips at the four corners, lubricate wheel axles monthly, and switch to anti-freeze grease in the cold season.
Empty-cage return is key: make cages foldable or stackable. Once a loaded cage is pulled away, empty cages stack on the dock, five to six layers high, waiting for the return truck to take them back to origin. Paint numbers and flow labels on the outside, use different colors for different outlets, and count cages hand to hand at the handover.
Nanjing Tongnuo Warehouse Equipment Manufacturing Co., Ltd. can build wheeled transit cages to sorting-line chute dimensions, standardizing wheel diameter, door type and color coding, and supports batch sampling to test how many cages a truck holds before locking the final design.