Though centrifugal bucket elevators are the most common design for elevating bulk materials, attempting to discharge a low-density bulk material such as wood fiber would lead to much of it free floating within the elevator housing. A continuous bucket elevator allows the material to discharge by gravity and slide out of the bucket, using the back of the preceding bucket as a ramp. Such a controlled discharge is preferred to maximize transfer efficiency. In addition, a belt-type elevator was used rather than a chain to avoid open areas where wood fibers could potentially snag and form clumps.