a method and apparatus for forming a fiber preform for use in molding fiber - reinforced , plastic articles is disclosed . the apparatus includes a perforated form which is rotated about its longitudinal axis while a vacuum is applied internally . cutters deposit short lengths of fibers on the rotating form by traversing the form from one end to another , and a binder resin is sprayed onto the fibers as they are deposited . the form is cylindrical and at least a major portion of its sidewall is initially covered with a flexible bellows . as the cutters traverse the form , the bellows is collapsed ahead of the cutters to incrementally expose the perforations . an oven is provided to cure the resin while the preform remains on the form .