Apparatus for the twin-wire air laying of fibrous pads

Claim 1

Apparatus for air laying fibers to form a composite pad comprising wall means defining a forming chamber having an inlet, a plurality of air removal openings, and an outlet, a pair of endless foraminous carriers supported for movement into said chamber, over respective ones of said air removal openings, and out said outlet, means for suspending fibers in air, means for directing said fibers suspended in air into said inlet between said carriers, means for applying pressure differential across said carriers in said chamber to force air from said suspension through said carriers and thence through respective ones of said air removal openings, said carriers blocking the passage of fibers therethrough, whereby respective layers of said fibers build up on said carriers, said carriers being supported within said chamber to converge in their direction of motion to join the facing surfaces of the respective layers to form a composite pad moving from said outlet between said carriers and at the same time substantially to block fibers suspended in air from flowing out of the outlet between said carriers, and fiber removal means adjacent the facing surfaces of said carriers, said fiber removal means comprising a source of reduced pressure, elongated restricted snout means having an inlet disposed contiguous to but spaced apart from and above the situs of convergence of said carriers and extending transversely across substantially the full width of said carriers, means substantially dividing said forming chamber into two portions and connecting said source of reduced pressure to said snout means for pulling air from said chamber across the exposed surface of each of said layers of fibers in the direction of forward movement of said layers at a relatively high velocity that shears excess fibers from the facing surfaces of said layers.