Controlled loft and density nonwoven webs and method for producing same
A lofty, nonwoven material having a nonwoven web having a plurality of substantially continuous fibers oriented in a z-direction of the nonwoven web and a method for producing the lofty, nonwoven material from as-formed z-direction fibers. The method is fast, having no mechanical manipulation of the fibers to slow it down, easily adjustable and allows for in-line processing. The material can be varied from preponderantly open to preponderantly closed in its web structure.
1. A lofted web of nonwoven material comprising: a plurality of substantially continuous fibers, the web having x, y and z directions, edges, and a first major surface in an x-y plane, with x being a machine direction, y being a cross machine direction and z being a loft direction;
the substantially continuous fibers oriented in the z-direction and folded to form loops;
the loops form a waved material with a train of waves spaced along the machine direction running from edge to edge in the cross direction and extending in the z-direction; and
the first major surface is flat; and
the web is integrally fixed with each wave being a substantially “U”-shaped wherein said U-shape has a bight protruding in the loft direction and the legs of the “U” are spaced along the machine direction and extend towards the first major surface and the legs of the “U” extending retrograde towards the first major surface.
2. A lofted web of nonwoven material comprising: a plurality of substantially continuous fibers, the web having x, y and z directions, edges, and a first major surface in an x-y plane, with x being a machine direction, y being a cross machine direction and z being a loft direction;
the substantially continuous fibers oriented in the z-direction and folded to form loops;
the loops form a waved material with a train of waves spaced along the machine direction running from edge to edge in the cross direction and extending in the z-direction; and
the first major surface is flat; and
the web is integrally fixed with each wave being a substantially “U”-shaped wherein said U-shape has a bight protruding in the loft direction and the legs of the “U” are spaced along the machine direction and extend towards the first major surface; and further including the legs of the “U” extending retrograde towards the first surface; and
said material being made by a method for producing a lofty, nonwoven material comprising the steps of:
directing a plurality of substantially continuous fibers into a nip; and
subjecting said substantially continuous fibers to a vacuum from both sides of said nip, producing a lofty, nonwoven web having z-direction oriented fibers; and
wherein said nip comprises two nip elements having a surface moving at different linear speeds in a machine direction.
3. A lofted web of nonwoven material comprising:
a single layer formed from a plurality of substantially continuous fibers, the single layer having x, y and z directions, edges, and a first major surface in an x-y plane, with x being a machine direction, y being a cross machine direction and z being a loft direction;
the substantially continuous fibers oriented in the z-direction and folded to form loops;
the loops form a waved material with a train of waves spaced along the machine direction running from edge to edge in the cross direction and extending in the z-direction; and
the first major surface is flat; and
the single layer being integrally fixed with each wave being substantially “U”-shaped wherein said U-shape has a bight protruding in the loft direction and the legs of the “U” are spaced along the machine direction and extend towards the first major surface; and further including the legs of the “U” extending retrograde towards the first major surface.
4. A lofted web of nonwoven material comprising:
a single layer formed from a plurality of substantially continuous fibers, the single layer having x, y and z directions, edges, and a first major surface in an x-y plane, with x being a machine direction, y being a cross machine direction and z being a loft direction;
the substantially continuous fibers oriented in the z-direction and folded to form loops;
the loops form a waved material with a train of waves spaced along the machine direction running from edge to edge in the cross direction and extending in the z-direction; and
the first major surface is flat; and
the single layer being integrally fixed with each wave being substantially “U”-shaped wherein said U-shaped has a bight protruding in the loft direction and the legs of the “U” are spaced along the machine direction and extend towards the first major surface; and further including the legs of the “U” extending retrograde towards the first surface; and
made by a method for producing a lofty, nonwoven material comprising the steps of:
directing a plurality of substantially continuous fibers into a nip; and
subjecting said substantially continuous fibers to a vacuum from both sides of said nip, producing a lofty, single layer nonwoven web having z-direction oriented fibers; and
wherein said nip comprises two nip elements having a surface moving at different linear speeds in a machine direction.