High loft low density nonwoven webs of crimped filaments and methods of making same
OwnerBraulio A. Polanco, Christopher Dale Fenwick +4inventors
InventorsBraulio A. Polanco, Christopher Dale Fenwick, Darryl Franklin Clark, Bryan David Haynes, Kurtis Lee Brown, Chad Michael Freese
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Abstract
High loft, low density nonwoven webs are produced by forming substantially continuous, spunbond, crimped, bicomponent fibers of A/B side by side morphology in an unheated fiber draw unit. The fibers are then heated and cooled in the absence of impeding forces to achieve maximum crimp in the z-direction and produce a web of lofted material. The resultant material is particularly suitable for use as an insulator. Particulates may be added to the webs if desired.
Claims34
A high loft, low density nonwoven web, the nonwoven web having x, y and z dimensions, with the x dimension being a machine direction, the y dimension being a cross machine direction and the z dimension being a loft direction, comprising:
- a web of substantially continuous, spunbond, crimped, bicomponent fibers of A/B side by side morphology, the fibers being randomly crimped to produce a material of high loft and of low density with heterogeneous fiber orientation, including heterogeneous z-direction orientation to produce loft of the web, and irregularly spaced openings between the crimped fibers.
A high loft, low density nonwoven web, the nonwoven web having x, y and z dimensions, with the x dimension being a machine direction, the y dimension being a cross machine direction and the z dimension being a loft direction, comprising:
- a web of substantially continuous, spunbond, crimped, bicomponent fibers of A/B side by side morphology, the fibers being randomly crimped to produce a lofted material with heterogeneous fiber orientation, including substantially heterogeneous z-direction orientation and shingled layers of buckled Z-orientation zones to produce loft of the web.
A high loft, low density nonwoven web, the nonwoven web having x, y and z dimensions, with the x dimension being a machine direction, the y dimension being a cross machine direction and the z dimension being a loft direction, consisting of:
- a web of substantially continuous, spunbond, crimped, bicomponent fibers of A/B side by side morphology, the fibers being randomly crimped to produce a lofted material with heterogeneous fiber orientation, including heterogeneous z-direction orientation to produce loft of the web, and irregularly spaced openings between the crimped fibers.
A method for producing a high loft, low density nonwoven web, the nonwoven web having x, y and z dimensions, with the x dimension being a machine direction, the y dimension being a cross machine direction and the z dimension being a loft direction, comprising:
- a) forming a group of crimpable, substantially continuous, spunbond, bicomponent fibers of A/B side by side morphology in an unheated FDU and depositing the group of fibers onto a forming wire;
- b) first heating the fibers at a time and a temperature sufficient to induce a relaxation of molecular orientation of one side of the fiber;
- c) after said first heating, cooling the group of fibers below the temperature where the fibers will bond to each other and thereby inducing the fibers to crimp;
- and
- d) controlling or minimizing the forces which tend to impede crimping of the fibers when performing steps b) and c) whereby the fibers are allowed to crimp in the z-direction.
Dependencies are inferred from the claim text.