Hydraulic-jet-treated stitchbonded fabric
AssigneeE. I. Du Pont de Nemours and Company
InventorDimitri P. Zafiroglu
Life of this patent
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Abstract
Stitchbonded fabrics are treated with columnar jets of water under specific conditions to rearrange fibers within the fabric so that holes caused by the stitches of the stitchbonding are substantially filled and the fabrics are made suitable for filter fabrics. The process requires at least the last part of the treatment to be performed on fine mesh screens with fine jets. The resultant fabrics are particularly suited for use as filter fabrics.
Claims7
A process wherein a stitchbonded fabric comprising a multi-needle stitched fibrous layer of substantially nonbonded fibers is subjected to a treatment wherein the stitchbonded fabric, while supported on a screen, is impacted by columnar jets of water, the stitchbonded fabric having initial compressed thickness in the range of 0.15 to 0.85 mm and a unit weight in the range of 50 to 350 g/m.sup.2, the jets imparting to the stitchbonded fabric a total impact-energy of at least 0.03 MJN/Kg, at least 0.02 MJN/Kg of the total impact-energy being imparted in a final part of the treatment with the stitchbonded fabric supported on a screen of no coarser than 40 mesh, and with the jets in the final part of the treatment being supplied through orifices of no greater than 0.15-mm diameter and being spaced with a frequency of at least 10/cm across the fabric, and the screen in the first part of the treatment having a thickness at least equal to the initial compressed thickness of the stitchbonded fabric.
A hydraulic-jet-treated stitchbonded fabric comprising a multineedle stitched layer of substantially nonbonded fibers, the fabric having a unit weight in the range of 50 to 350 g/m.sup.2, a Frazier air permeability of at least 0.3 m.sup.3 /min, a bulk of at least 6 cm.sup.3 /gram and a dust filtration leakage of no greater than 0.3 gram per day.
Dependencies are inferred from the claim text.