An automated conveyor system that identifies cases, totes or parcels and diverts each one to the right lane, chute or dock door, used in distribution and parcel centers.
Detailed Definition
A sortation system reads an identifier on each item, usually a barcode and sometimes an RFID tag, and a control system tells a divert mechanism where to send it. Common sorter types include sliding shoe, pop-up wheel or roller, cross-belt, tilt-tray and bomb-bay designs. Sorted items collect by store, route or carrier, where they are built onto pallets or loaded straight into trailers. Whole pallets are usually moved by forklifts, AGVs or pallet conveyors rather than by high-speed sorters.
How items move through a sorter
Items are inducted onto the sorter, spaced out, and scanned. The warehouse control system matches each scan to an order or route and triggers the divert at the right moment, pushing, tilting or dropping the item into its destination. Items that cannot be read or have no valid destination go to a recirculation loop or an exception lane for manual handling. Label quality and placement matter, because unread items slow the whole system.
Where sortation meets the pallet
On the outbound side, sorted cases arrive at lanes for each store or route and are stacked onto pallets by hand or by a robotic palletizer, then wrapped and labeled for shipping. In cross-dock operations, inbound pallets are broken down, the cases are sorted to outbound doors, and new mixed pallets are built for each destination without the product going into storage.
What limits sorter performance
- Items that are too small, heavy, soft, round or fragile to convey reliably.
- Damaged, wet or poorly sealed cartons.
- Missing or unreadable barcodes.
- Downstream bottlenecks, such as too few people building pallets at the lanes.
Related Glossary Terms
Frequently Asked Questions
Can a sorter handle every carton?
No. Every sorter has a conveyable range for size, weight and package type. Items outside that range, often called non-conveyables, such as very long, very heavy, bagged or irregular items, need a separate manual or pallet-based process. Facilities usually publish packaging requirements to suppliers so that most cases are conveyable. When you ship into a sorter-based DC, check the receiver's carton and labeling specifications.
What is the difference between sortation and cross-docking?
Sortation is the equipment and process of directing individual items to destinations. Cross-docking is an operating strategy in which inbound goods are moved to outbound shipments with little or no storage. Many cross-dock facilities use sortation to split inbound pallets into cases and route them to outbound doors, but cross-docking can also be done manually, and sorters are also used in conventional warehouses and parcel hubs.