When a roll of fabric is produced on a nonwoven line, most customers want the edges of the fabric to be straight and the fabric to be a consistent width. For these reasons the raggedy edges are trimmed off. The material that is trimmed off can be thrown away or recycled. If the fibers in the fabric are not melted or glued together, then the trim can be reopened into individual fibers and recycled. This is often the case on a needlepunch production line.
The machine that opens the fibers and sends them back to the fiber system is called an edge trim shredder. Several companies make these machines and they are all similar. Usually they consist of a wire covered or fluted feed roll/ feed plate assembly, an opening cylinder that may be covered with pins or with wire, and a fan.
In the pictures you can see that the trim enters the machine through a safety grill that prevents fingers and hands from getting hurt. The trim goes under the feedroll and over the nose of the feed plate. The cylinder turns at very high speed and shreds the fabric into individual fibers as it is combed off the feed plate. The fan sucks the fibers off the cylinder and sends them to either a fiber reserve or a feed hopper.