Nonwoven machines using staple fiber commonly move the fiber between the various opening machines through ductwork. The fiber can either be blown through or sucked through the ducts. One piece of equipment used to do this is a fiber fan. A fiber fan is a special type of centrifugal fan with blades made so fiber can actually pass through the fan. One would think that fiber would get tangled in the fan blades. However, the blades are made on a rotating disk and angle outward from the center of the disk. This design allows for the generation of air movement while preventing the fibers from getting entangled in the blades.
Smaller fiber fans are usually directly coupled to the motor while larger ones are belt driven from the motor. Safety is an important issues with these fans. They often have a cleanout door as they should be regularly inspected for nicks on the blades as well as buildup on the blades. The door must have a mechanical switch that requires several minutes to unscrew so that the fan will be at a complete stop and cannot start once the door is open.
Some fiber fans have motors that are controlled by inverters. This enables the fan speed to be changed while the fan is running. This is advantageous when changes are made in fiber length, type of fiber, or fiber denier.