Needling loops into carrier sheets
View Patent ↗A sheet-form loop product includes a flexible paper substrate and a layer of staple fibers disposed on a first side of the substrate, exposed loops of the fibers extending from holes through the substrate to a second side of the substrate, with bases of the loops being anchored on the first side of the substrate. The loops can be fastening loops. The product is formed by needling the fibers through the paper and then bonding the fibers. Examples include loop fastener materials, towels, abrasive scrubbing pads and sanding materials.
1. A method of making a sheet-form loop fastener product, the method comprising
placing a layer of staple fibers against a first side of a flexible paper substrate;
needling fibers of the layer through the paper substrate by piercing the substrate with needles that drag portions of the fibers through holes formed in the paper substrate during needling, forming loops of the fibers extending from the holes on a second side of the paper substrate;
selecting needling parameters so that the loops have a size and structure selected to engage a field of corresponding male fastener elements; and
anchoring fibers forming the loops sufficiently to resist pull-out loads caused by releasable engagement with the male fastener elements.
2. The method of claim 1 wherein the fibers include bicomponent fibers having a core of one material and a sheath of another material, and wherein anchoring the fibers comprises melting material of the sheaths of the bicomponent fibers to bind fibers together.
3. The method of claim 1 wherein needling fibers of the layer through the paper substrate and anchoring fibers forming the loops forms loops sized and constructed to be releasably engageable by a field of hooks for hook-and-loop fastening.
4. The method of claim 1 wherein the staple fibers are disposed on the substrate in a layer of a total fiber weight of less than about 2 ounces per square yard (67 grams per square meter).
5. The method of claim 4 wherein the staple fibers are disposed on the substrate in a layer of a total fiber weight of no more than about one ounce per square yard (34 grams per square meter).
6. The method of claim 1 wherein the staple fibers are disposed on the substrate in a carded, unbonded state.
7. The method of claim 1 further comprising, prior to disposing the fibers on the substrate, carding and cross-lapping the fibers.
8. The method of claim 1 wherein the loop product has an overall weight of less than about 5 ounces per square yard (167 grams per square meter).
9. The method of claim 1 wherein anchoring occurs subsequent to needling.