off by a feed roll 6 which has a rotary axis 6 u2032 a direction of rotation 6 a and which cooperates with a feed tray array 7 formed of a plurality of individual feed trays 7 a as shown in fig4 b the fiber material iii is advanced from the reserve chute 2 by means of the slowly rotating feed roll 6 to a rapidly rotating opening roll 8 having pins 8 b or a sawtooth clothing on its circumferential surface one part of the circumference of the opening roll 8 faces a lower feed chute 9 the opening roll 8 which rotates in the direction of the arrow 8 a advances the fiber material iii into the lower chute feed chute 9 the feed chute 9 has at its lower end a withdrawing roll 10 which advances the fiber material to the roller card unit 1 the fiber feeder may be an exactafeed model manufactured by trutzschler gmbh amp co kg monchengladbach germany also referring to fig3 the lower part of the walls of the feed chute 9 are provided with air outlet openings 11 to separate the air stream v from the fiber stream vi at the top above the feed roll 6 the feed chute 9 is in communication with a duct 12 coupled to the output of a blower 32 the rotating feed roll 6 and the opening roll 8 continuously advance the mixture iv of air and fiber material at a certain flow.