Apparatus for producing multilayer fibrous structures

Claim 1

Apparatus for producing multilayer fibrous mats which comprises an elongate cylindrical separating wall having sifting openings uniformly distributed substantially over its entire circumferential areas, a rotary shaft journalled in said wall, a disintegrating means rotatably mounted on said shaft and operatively associated with said separating wall for disintegrating undispersed short-length fiber flocks of woodpulp fibers into finely dispersed elementary fibers, a casing disposed in surrounding relation to said separating wall and defining therewith an annular dispersing chamber having a downwardly directed fiber outlet for dispersed fibers, said casing flaring pRogressively towards said fiber outlet and being provided in opposite sides thereof with an elongate aperture communicating with the atmosphere for introducing a controlled volume of air into said chamber, a damper provided at the upper end of said dispersing chamber for regulating the volumetric ratio of air to fibers within said chamber, a moving endless wire conveyor underlying said fiber outlet for the deposition thereon of dispersed fibers, and defibration means for producing individually separated long fibers from chemical or synthetic fibers for mixing with the disintegrated short-length fibers, said means comprising a funnel extending to substantially full operating length of said casing and communicating with said fiber outlet, a plate member and a defibrator roll operatively associated therewith for separating a lap into individual long fibers.