A method of forming carded fibers of different materials. A feed system has a plurality of separate laterally spaced chambers containing fibers of different materials. The different fibers are fed in separate laterally spaced paths into a carding apparatus having a plurality of rollers and cylinders each having laterally spaced sections in alignment with the laterally spaced paths to receive and maintain the different fibers in the laterally spaced paths thereon as they move through the carding apparatus. The different fibers are combined into a multi-fiber roving or web after they exit the carding apparatus. Depending on the composition of the different fibers, they may be combined by conveying them through a humidifying and heated chamber or chambers.

A fiber preparation machine for processing fiber material includes a store or filling chute for storing the fiber material before or after processing. A camera is directed into an interior of the store or filling chute, the camera having an optical axis oriented at an angle () with respect to a vertical axis that is perpendicular to a surface of the fiber material in a range of plus 30 degrees to minus 30 degrees. The camera has a resolution for detecting a particle having an extension of 0.1 mm2 on the surface of the fiber material.

A fiber preparation machine for processing fiber material includes a store or filling chute for storing the fiber material before or after processing. A camera is directed into an interior of the store or filling chute, the camera having an optical axis oriented at an angle () with respect to a vertical axis that is perpendicular to a surface of the fiber material in a range of plus 30 degrees to minus 30 degrees. The camera has a resolution for detecting a particle having an extension of 0.1 mm2 on the surface of the fiber material.