Patent ID: 6877970

Claim:
An apparatus for making a web comprising continuous fibers of a thermoplastic synthetic resin, said apparatus consisting essentially of: a melt extruder having a plurality of nozzles from which the continuous fibers of said thermoplastic synthetic resin are to be extruded; a conveyor running in a machine direction for collecting thereon the continuous fibers extruded from said melt extruder; a guide box of a trapezoid shape located between said extruder and said conveyor and having an upper end opening at a small base of said trapezoid shape, said upper end opening being located immediately below the nozzles of said extruder and spaced from the nozzles by a free space of a desired dimension, and a lower end opening at a large base of said trapezoid shape, said lower end opening having a dimension measured in the machine direction larger than that of said upper end opening; and a single suction source located opposing said lower end opening of said guide box with said conveyor therebetween; wherein said guide box has front and rear walls spaced in the machine direction and side walls extending between said front and rear walls; at least one of said front and rear walls is provided with at least one intermediate opening lying between said upper and lower end openings end allowing an air flow between an exterior and an interior of said guide box; said at least one intermediate opening is adjustable by at least a shutter operatively associated with said at least one intermediate opening; said shutter comprises a plate moveable parallel to the respective front or rear wall in which the associated intermediate opening is formed; and each of said front and rear walls has only one said intermediate opening.