Flipping pallet loads has evolved from an art to a science at Quebecor World, a printer in Clarksville, Tn.

There, the challenge was to create a system that could invert loads of printed signatures (groups of pages printed as a unified unit). At most printing plants, the codes on the signatures must face up before they are fed into the bindery pockets. This generally requires bindery personnel to flip the bundles of signatures by hand before they can be placed in the bindery pockets.

A pallet inversion system eliminates that manual process, and problems associated with it, most notably carpal tunnel syndrome of the hands and wrists from performing repetitive motions.

The process begins when a forklift operator places a load to be inverted on an in-feed conveyor line. Before the load can enter the inverter, it is centered from front to back and from left to right by a stop bar that rises up between two rollers that stops the load as the rollers continue to push forward. A pallet placer lowers a plastic pallet on top of the load, prior to being inverted.

The load is then conveyed into the inverter. Once inside, a top plate comes down to compress and hold the palletized signatures. The entire chamber then rotates 180 degrees, in a simple clockwise motion.

After rotation, the load exits to the next conveyor section, where four pneumatic actuators clamp and remove the plastic pallet. The load continues to the end of the line where a forklift operator removes it, ready to go to the bindery or storage area.