High loft, low density nonwoven webs are produced by forming substantially continuous, spunbond, crimped, bicomponent fibers of A/B bilateral 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.