ANISOTROPIC EXTENSIBLE NONWOVENS
This invention relates to nonwoven fabrics in which the fibers of the fabric are laid down such that a majority of the fibers have a fiber direction making an angle substantially parallel to or within an angle in a range of +/−45° of the machine direction. The invention also relates to a nonwoven fabric bonded web having bonding points in a pattern arranged along an axis perpendicular to the machine direction spaced and more widely apart than the bonding points arranged along an axis parallel to the machine direction. The resulting nonwoven having a very low elongation in the machine direction can be elongated with relatively little force in the cross machine direction.
1 . An extensible nonwoven having substantially different physical properties in the machine direction versus the cross direction, characterized in that said nonwoven has a cross direction elongation of at least about 50 percent.
2 . The extensible nonwoven of claim 1 having a cross direction elongation of about 100 to about 200 percent.
3 . The extensible nonwoven of claim 1 selected from the group comprising:
spunbonded, melt blown, carded thermally bonded, and spunlaced structures.
4 . A process for making an extensible nonwoven comprising the steps of: laying down a fibrous web and bonding the web by selecting a bonding pattern comprising a plurality of bonding points and wherein, the bonding points arranged along an axis perpendicular to the machine direction are spaced more widely apart than the bond points arranged along an axis parallel to the machine direction and wherein the bonding points are provided by thermal energy.
5 . A process for making an extensible nonwoven comprising the steps of: aligning carded bats of fibers such that a majority of the fibers have a fiber direction making an angle substantially parallel to or within an angle in a range of +/−45° of the machine direction and bonding the web.
6 . A process for making an extensible nonwoven comprising the steps of: laying down a fibrous web using randomizing air jets such that a majority of the fibers have a fiber direction making an angle substantially parallel to or within an angle in a range of +/−45° of the machine direction and bonding the web.