FIELD: production of corrugated constructions from fibrous filler having variable density with corrugations bound by resins or by thermal treatment. SUBSTANCE: corrugated construction has fibrous fabric folded so as to form plurality of creases having ridges and bases arranged in alternation. Each crease has two sides, each having first and second surfaces. First surface of one side of crease is in contact with first surface of adjacent side of crease and second surface of one side of crease is in contact with second surface of adjacent side of crease. Distance between first surface of ridges and second surface of bases defines thickness of construction. At least some of ridges define first surface of construction and at least some of bases define second surface of construction. Creases are arranged through thickness of construction so that density of construction between first and second surfaces has variable values. Method involves folding fibrous construction; providing first surface defined by certain number of ridges and second surface defined by certain number of bases to produce corrugated fibrous fabric having different density values between mentioned surfaces. Fibrous fabric has first and second filaments extending in alternate directions so as to form alternate connecting members. Method further involves binding creases of fibrous fabric by means of resins or thermal treatment. EFFECT: increased strength and resiliency of construction having smooth and even surface, increased compression strength and improved air-permeability. 31 cl, 38 dwg
