Sorter

A machine reads a label or barcode on each parcel or item as it passes by and sends it to the right place on its own. At speed it pushes, tips or drops each one into a lane, chute or container, one for every destination. Hundreds or thousands of items an hour end up where they belong without anybody reading an address; this machine is called a sorter.

Sorters come in several designs. Tilt-tray and cross-belt sorters carry items on small trays or belts that tip them sideways, sliding-shoe and pop-up wheel sorters push items off a belt, and pocket sorters hang items in bags. Which fits depends on the item: flat parcels, polybags, cartons and garments each behave differently.

A sorter is usually the last stage before despatch, sorting by carrier, route or store, but it is also used earlier, to sort picked items into orders.

When it pays off

A sorter pays off when many items a day have to be split among many destinations, such as parcels by carrier or route, store replenishment or returns. The volume has to be high enough to keep it busy, because the machine, its chutes and its control are a fixed cost. It pays off less at a few hundred parcels a day, where manual sorting into a few cages is quicker, and for items of very mixed shape that jam. With only a few destinations, a simple diverter on a conveyor may be enough.

What the warehouse system does with it

The WMS, or the order system, tells the sorter's control what belongs where: which order, carrier, route or store each barcode goes to, and the lane or container for each destination. The sorter reads the label and sends the item there; at the end it reports what went where and what could not be read or was rejected. Rejected items go to a manual lane, and the WMS keeps the record of what was sorted into which container, so that the container can be closed and despatched.

Who makes it

Alstef Group, BEUMER Group, Eurosort, Honeywell Intelligrated, Körber, TGW

In alphabetical order. Not a ranking or a recommendation.