The carding machine is a tool consisting of a bench, shaped like a seat on one side and supported by four legs. On the opposite side to the seat is a sort of box, equipped with very large and hooked nails positioned in opposite directions, above which is a frame that supports a curved tilting surface, also equipped with nails in opposite directions and adjustable in height. The tilting surface of the carding machine was moved back and forth, so that the wool, positioned between the latter and the base, could be "frayed" thanks to the nails present and made very airy for the purpose of filling mattresses or pillows. Basically, the carding machine performs the opposite operation to that of the carder, with which the knots are untied and the fibres are positioned in the same direction for the purposes of spinning.