Abstract: The web or mat producing unit including a fiber opening and doffing mechanism mounted on a vertically adjustable platform to direct fibers randomly downwardly through an opening in the platform and onto the horizontal upper run of an endless screen, which travels in one direction over a vacuum or suction opening positioned beneath and parallel to the upper run. Two, spaced side curtains or panels, which are suspended from the underside of the platform, guide fibers into a predetermined space located between opposite sides of the upper run of the screen, thereby to form the fibers into a shingle-free nonwoven mat which may, if desired, be fed successively onto the upper run of the screen in the next successive unit in a series thereof. The width and configuration of the mat can be changed by adjusting the panels toward and away from each other, and by placing a removable template or baffle over the suction opening.