摘要:
Nonwoven fibrous webs include elastic filaments such that the web as a whole exhibits elastic properties when stretched. The webs include a multiplicity of nonwoven fibers and at least one elastic filament entangled with at least a portion of the nonwoven fibers to form a self-supporting, cohesive, elastic nonwoven fibrous web. Methods of making such elastic nonwoven fibrous webs using hydro-entanglement, and uses of such webs to form articles are also described.
摘要:
Nonwoven fibrous webs include elastic filaments such that the web as a whole exhibits elastic properties when stretched. The webs include a multiplicity of nonwoven fibers and at least one elastic filament entangled with at least a portion of the nonwoven fibers to form a self-supporting, cohesive, elastic nonwoven fibrous web. Methods of making such elastic nonwoven fibrous webs using hydro-entanglement, and uses of such webs to form articles are also described.
摘要:
The present invention is directed at a hook mechanical fastener/fibrous composite comprising hook elements on hook containing backing elements or a netting embedded in a fibrous web. The hook elements preferably are on backing elements that are connected or integral and can be strands oriented at angles to each other in a net form. The backing elements generally have a first outer face and a second outer face. The backing elements on at least one of the first or second outer faces have a plurality of hook elements. The hook containing backing elements are embedded within a fibrous web, preferably by hydroentangling the fibers around the backing element, preferably without use of auxiliary attachment means such as adhesives or point bonding.
摘要:
A coherent nonwoven fibrous web comprises directly formed elastic fibers that have a molecular orientation sufficient to provide a birefringence number of at least 1×10−5 and preferably at least 1×10−2. The web can be made by a method that comprises a) extruding filaments of elastic-fiber-forming material; b) directing the filaments through a processing chamber in which gaseous currents apply a longitudinal stress to the filaments that attenuates and draws the filaments; c) maintaining the filaments at their orienting temperature while the filaments are under attenuating and drawing stress for a sufficient time for molecules within the filaments to become oriented along the length of the filaments; d) cooling the filaments to their orientation-locking temperature while the filaments are under attenuating and drawing stress and further cooling the filaments to a solidified fiber form; and e) collecting the solidified fibers as a fibrous nonwoven web. In a preferred aspect, the method includes the further step of annealing the collected fibers by exposing them to a temperature that is above their shrinking temperature but less than their relaxation temperature, and preferably bonding the fibers after (or before) the annealing step. Dimensionally stable webs comprising elastic oriented fibers are obtained.
摘要:
A porous monocomponent nonwoven web contains a bimodal mass fraction/fiber size mixture of intermingled continuous microfibers and larger size fibers of the same polymeric composition. There are at least five times as many microfibers as larger size fibers, and a histogram of the mass fraction of fibers vs. fiber size exhibits a larger size fiber mode greater than 10 μm. The web may be made by flowing fiber-forming material through a die cavity having larger size orifices and at least five times as many smaller size orifices to form filaments, attenuating the filaments into fibers and collecting the attenuated fibers to form the nonwoven web. The web is especially well suited to the manufacture of self-supporting three dimensional articles such as molded cup-shaped respirators and pleated air filters.
摘要:
A nonwoven fibrous web comprising a matrix of continuous meltspun fibers bonded to a coherent self-sustaining form, and separately prepared microfibers dispersed among the meltspun fibers. The microfibers may have median diameters less than one or two micrometers. A method for preparing such a nonwoven fibrous web comprises establishing a stream of continuous oriented meltspun fibers having a longitudinal axis, establishing a stream of meltblown microfibers that exit a meltblowing die at a point near the stream of meltspun fibers, the meltblown stream being aimed to merge with the meltspun stream and having a longitudinal axis that forms an angle of between 0 and 90 degrees to the longitudinal axis of the meltspun stream, capturing the meltblown fibers in the stream of meltspun fibers, and collecting the merged stream as a web on a collector spaced near the intersection point of the meltspun and meltblown streams.
摘要:
A pleated filter is made from a monocomponent monolayer nonwoven web containing a bimodal mass fraction/fiber size mixture of intermingled larger size and smaller size continuous monocomponent polymeric fibers of the same polymeric composition. Rows of pleats are formed in the nonwoven web, and the pleated web is cut to a desired size and shape to provide a filter element containing a self-supporting porous monocomponent monolayer matrix of fibers bonded to one another at least some points of fiber intersection and having an average initial submicron efficiency of at least 15% at a 1.52 meters/sec face velocity. The filter element is deformation resistant without requiring stiffening layers, bicomponent fibers or other reinforcing measures in the filter media layer.
摘要:
Shaped filtration articles are made from a monocomponent nonwoven web formed by flowing first and second fiber-forming materials of the same polymeric composition through first and second die cavities in respective fluid communication with first and second sets of orifices in a meltblowing die tip. The first fiber-forming material flows at a lesser flow rate or viscosity through the first die cavity and first set of orifices to form a set of smaller size filaments and the second fiber-forming material flows at a greater flow rate or viscosity through the second die cavity and second set of orifices to form a set of larger size filaments. The collected nonwoven web contains a meltblown bimodal mass fraction/fiber size mixture of intermingled continuous microfibers and larger size fibers of the same polymeric composition.
摘要:
Multilayered polymer films are configured so that successive constituent layer packets can be delaminated in continuous sheet form from the remaining film. The new films are compatible with known coextrusion manufacturing techniques, and can also be made without the use of adhesive layers between layer packets that are tailored to be individually peelable from the remainder of the film. Instead, combinations of polymer compositions are used to allow non-adhesive polymer layers to be combined in such a way that delamination of the film is likely to occur along a plurality of delamination surfaces corresponding to interfaces between particular pairs of layers for which the peel strength is reduced relative to the peel strength at other layer interfaces within the film. The absence of an adhesive between peelable layer packets results in the delamination being irreversible.
摘要:
A molded respirator is made from a monocomponent monolayer nonwoven web containing a bimodal mass fraction/fiber size mixture of intermingled continuous monocomponent polymeric microfibers and larger size fibers of the same polymeric composition. The respirator is a cup-shaped porous monocomponent monolayer matrix whose matrix fibers are bonded to one another at least some points of fiber intersection. The matrix has a King Stiffness greater than 1 N. The respirator may be formed without requiring stiffening layers, bicomponent fibers, or other reinforcement in the filter media layer.