Method and apparatus (discontinuous imperforate portions on backing means of open sandwich)

Claim 1

Apparatus for producing a patterned nonwoven fabric having a plurality of patterns of areas of low fiber density that alternate and extend throughout said fabric, from a layer of fibrous starting material whose individual fibers are in mechanical engagement with one another but are capable of movement under applied fluid forces, which comprises: backing means for said layer of fibrous starting material, said means having portions which are imperforate and portions which are foraminous, said imperforate portions being discontinuous and said foraminous portions being continuous and interconnecting the discontinuous imperforate portions, said continuous foraminous portions comprising at least 10 percent of the total area of the backing means, said foraminous portions having a plurality of protuberances and troughs alternating across the surface thereof in both the longitudinal and transverse directions, the tops of said protuberances rising above the bottoms of said troughs by a distance of at least .005 inch, the width of each trough being at least 0.025 inch, each of said discontinuous imperforate protions extending along the surface of the backing means a distance at least about twice the horizontal distance from the center of one of said troughs to the center of the trough immediately adjacent and parallel to it, and each pair of immediately adjacent discontinuous imperforate portions spanning between them at least one of said protuberances and at least part of one of said troughs on each side of said one protuberance; means for moving said backing means, with a layer of fibrous starting material positioned thereon, through a rearranging zone; means for projecting streams of rearranging fluid against said fibrous layer substantially uniformly and continuously across the surface thereof to pass through said layer, some of said fluid streams striking said imperforate portions of the backing means and other of said fluid streams striking said protuberances on the backing means, all to be deflected thereby in sidewise directions and all of said fluid streams, together with other streams of fluid that do not strike the backing means, passing through and beyond said foraminous portions of the backing means; and means to apply vacuum on the side of said backing means opposite to said fibrous layer to assist in moving all said rearranging fluid through the fibrous layer and in rearranging the fibers of said layer.