Patent ID: 8562879

Claim:
A method of making a gravity-laid inorganic fiber web, comprising: introducing inorganic fibers into a first forming chamber that comprises a plurality of first fiber-separating rollers provided in at least one row within the first forming chamber and that comprises a first moving endless belt screen; mechanically separating at least some of the inorganic fibers with the first fiber-separating rollers; capturing any remaining agglomerates of the inorganic fibers by the first moving endless belt screen and returning the captured agglomerates to the first fiber-separating rollers to be mechanically separated by the first fiber-separating rollers; collecting the mechanically separated inorganic fibers; introducing at least some of the collected mechanically separated inorganic fibers into a second forming chamber that comprises a plurality of second fiber-separating rollers provided in at least one row within the second forming chamber and that comprises a second moving endless belt screen; mechanically separating at least some of the inorganic fibers with the second fiber-separating rollers of the second forming chamber; capturing any remaining agglomerates of the inorganic fibers by the second moving endless belt screen and returning the captured agglomerates to the second fiber-separating rollers to be mechanically separated by the second fiber-separating rollers; collecting the mechanically separated inorganic fibers as a gravity-laid inorganic fiber mat; removing the gravity-laid inorganic fiber mat from the second forming chamber; and, consolidating the gravity-laid inorganic fiber mat to form a gravity-laid inorganic fiber web.