Laminate floors are particleboard planks topped with a wood veneer, then topped with clear gloss. When laminate floors get dull and worn, you shouldn't fully sand them as you might a hardwood floor, because you're likely to take off the wood veneer layer. A more prudent approach is to screen-sand the floor, using a screening disk that's designed to remove the top layers of gloss but not affect the wood veneer, the re-gloss. Normally, screening involves rough, medium and fine screens, but for laminate, skip the rough screen.
Set up your floor buffer with a medium screening disk.
Set the machine in one corner of the room and turn it on. Begin moving it immediately, running it along the direction of the laminate boards.
Screen the entire laminate floor, always running the buffer with the direction of the floorboards. Keep the buffer moving at all times while it's running. The screen should take up the very top layer of gloss from the laminate floor, without digging into the wood itself.
Sweep up the dust with a broom.
Re-load the buffer with a fine screening disk. Repeat Step 1, going over the whole floor, moving the machine with the direction of the floorboards. The fine disk should smooth out the floor surface, leaving the finish dull and flat, but not affecting the wood layer underneath.
Sweep up the dust. The floor is now ready for re-glossing.