Method for producing a variable density, corrugated resin-bonded or thermo-bonded fiberfill and the structure produced thereby

A corrugated fiberfill structure comprising two fibrous webs folded to form a plurality of pleats having alternating crests and bases, each of the pleats having a pair of legs, each of the legs having a first leg surface and a second leg surface, the first leg surface of a first leg being in intimate contact with the first leg surface of an adjoining leg of the pleat and the second leg surface of the first leg being in intimate contact with the second leg surface of an adjoining leg of an adjacent pleat over a portion of each leg, at least some crests defining a first structural surface and at least some bases defining a second structural surface, a line transverse to and between the first and second structural surfaces defining a thickness direction of the structure, the pleats of the structure being arranged so that the structure has a density that varies in the thickness direction between the first and second structural surfaces wherein the legs of adjoining pleats are unequal in length.

A corrugated fiberfill structure comprising three fibrous webs folded to form a plurality of pleats having alternating crests and bases, each of the pleats having a pair of legs, each of the legs having a first leg surface and a second leg surface, the first leg surface of a first leg being in intimate contact with the first leg surface of an adjoining leg of the pleat and the second leg surface of the first leg being in intimate contact with the second leg surface of an adjoining leg of an adjacent pleat over a portion of each leg, at least some crests defining a first structural surface and at least some bases defining a second structural surface, a line transverse to and between the first and second structural surfaces defining a thickness direction of the structure, the pleats of the structure being arranged so that the structure has a density that varies in the thickness direction between the first and second structural surfaces wherein the legs of adjoining pleats are unequal in length.

A corrugated fiberfill structure comprising at least one fibrous web folded to form a plurality of pleats having alternating crests and bases, each of the pleats having a pair of legs, each of the legs having a first leg surface and a second leg surface, the first leg surface of a first leg being in intimate contact with the first leg surface of an adjoining leg of the pleat and the second leg surface of the first leg being in intimate contact with the second leg surface of an adjoining leg of an adjacent pleat over a portion of each leg, at least some crests defining a first structural surface and at least some bases defining a second structural surface, a line transverse to and between the first and second structural surfaces defining a thickness direction of the structure, the pleats of the structure being arranged so that the structure has a density that varies in the thickness direction between the first and second structural surfaces wherein crest portions and base portions of at least some of the pleats are folded and at least partially overlap and contact corresponding crests and base portions, respectively, of adjacent pleats.

A method for forming a corrugated bonded fiberfill structure having pleats, a first surface defined by crests of at least some of the pleats, and a second surface defined by bases of at least of some of the pleats, the method comprising:

• lapping at least one fibrous web formed from first fibers and second fibers in alternating directions to form alternating pleats, adjoining pleats having unequal lengths, to form a corrugated fibrous web varying in density between the first and second surfaces;
• and
• bonding the pleats of the corrugated fibrous web.

A corrugated fiberfill structure comprising at least one fibrous web folded to form a plurality of pleats having alternating crests and bases, each of the pleats having a pair of legs, each of the legs having a first leg surface and a second leg surface, the first leg surface of a first leg being in intimate contact with the first leg surface of an adjoining leg of the pleat and the second leg surface of the first leg being in intimate contact with the second leg surface of an adjoining leg of an adjacent pleat over a portion of each leg, at least some crests defining a first structural surface and at least some bases defining a second structural surface, a line transverse to and between the first and second structural surfaces defining a thickness direction of the structure, the pleats of the structure being arranged so that the structure has a density that varies in the thickness direction between the first and second structural surfaces wherein fibers from at least some of the crests and at least some of the bases extend to adjoining crests and bases, respectively, bridging gaps between adjacent crests and adjacent bases, thereby defining the first and second surfaces.