On a drum carder, the fibers are deposited on the large drum, after a short carding process between the small and the large drums.

The fundamental differences between the industrial carders and the drum carders have resulted in the following design and operating consequences for the Louet drum carders:

The most important difference between the Louet drum carders and other drum carders is the method of supplying fiber to the drums. Most drum carders have a feed tray where teased fibers are deposited and then pushed towards the small or intake drum. Next, this intake drum transports the fibers to the large drum. The Louet drum carder has a small board below and in front of the in-take drum. This board exists for construction purposes only. The board is not designed to be a feed tray.