Are you struggling with an enormous workload that never seems to let up? If so, the U.S. Postal Service (USPS) knows just how you feel. The federal mail service, which reaches every address in the coun try no matter how remote, handles an estimated 213 billion (yes, that's billion with a "b") pieces of mail in every con ceivable shape and size each year. That's more than 29 million pieces per hour.

To help it keep those letters and parcels flying through its system day in and day out, the USPS needed flexible material handling solutions that could process all those items at high speeds. Toward that end, the agency has launched the High Speed Universal Sorter (HSUS) initiative, a project that grew out of its search for a sortation system that could handle inconsistent volumes of a wide array of mail, packages, sacks, and containers.

USPS found what it needed in the UniSort Linear Belt Sorter manufactured by FKI Logistex. Packages ride along on moving slats, each of which contains a flat belt. When it's time to divert a piece of mail, package, or container, an electric switch releases the necessary number of belts, which then push the item off the sorter bed.

With so much variation in the quantities and types of items the USPS receives, flexibility was a top priority. The new sorter can simultaneously handle more than one type of item—sacks and irregular packages, for instance. Flexible configuration was another consideration for the Postal Service. The solution: design the sortation system in subassemblies and modules so that individual facilities could customize the equipment for their own space and mix of items.