Post-treatment of laminated nonwoven cellulosic fiber webs
AssigneeThe University of Tennessee Research Corporation
InventorsCharles B. Hassenboehler, Jr., Larry C. Wadsworth
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Abstract
A method for post-treating a laminated precursor nonwoven web which includes layers of thermoplastic man-made fibers and at least one layer of cellulose-based staple natural fibers, including consolidating the web laterally and thereby reducing the maximum pore size measure of the web. The precursor web and the resultant consolidated nonwoven web are also disclosed, as is utilization of the product web in medical uses.
Claims45
A planar consolidated multilayered nonwoven web which is consolidated in the cross-direction having a reduced maximum pore size which is at least 20% less than that of the web prior to consolidation, wherein the web comprises first and third layers which each comprise a layer of randomly organized, nonelastomeric thermoplastic man-made fibers bonded to each other, said thermoplastic fibers having a crystallinity prior to consolidation of at least 30%, and a second layer, sandwiched between said first and third layers, which second layer comprises non-wood cellulose-based staple fibers, and wherein in at least one of said first or third layers a majority of the fibers are aligned generally in the direction of draw and a minority of the fibers are disposed in a cross-direction transverse to the direction of draw.
A method for forming a planar consolidated multilayered nonwoven web which comprises at least one thermoplastic component, which method comprises concurrently heating a nonwoven precursor web to a temperature between the softening temperature and melting temperature of at least one of the thermoplastic components and drawing the web in a substantially longitudinal direction which web comprises first and third layers which each comprise a layer of randomly organized, nonelastomeric thermoplastic man-made fibers bonded to each other, said thermoplastic fibers having a crystallinity of at least 30%, and a second layer, sandwiched between said first and third layers, which second layer comprises non-wood cellulose-based staple fibers, wherein, in at least one of said first or third layers, a majority of the fibers are aligned generally in the direction of draw and a minority of the fibers are disposed in a cross-direction transverse to the direction of draw, and forming the consolidated web which has a reduced maximum pore size by at least 20% than that of the web prior to consolidation.
Dependencies are inferred from the claim text.