Abstract: 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.

Abstract: 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.

Abstract: Nonwoven fibrous webs comprise fibers of uniform diameter that vary in morphology along their length. The variation provides longitudinal segments that exhibit distinctive softening characteristics during a bonding operation. Some segments soften under the conditions of the bonding operation and bond to other fibers of the web, and other segments are passive during the bonding operation. Webs as described can be formed by a method that comprises a) extruding filaments of fiber-forming material; b) directing the filaments through a processing chamber in which the filaments are subjected to longitudinal stress; c) subjecting the filaments to turbulent flow conditions after they exit the processing chamber; and d) collecting the processed filaments; the temperature of the filaments being controlled so that at least some of the filaments solidify while in the turbulent field.

Abstract: Nonwoven fibrous webs including amorphous polymeric fibers with improved and/or more convenient bondability are disclosed. The nonwoven fibrous webs may include only amorphous polymeric fibers or they may include additional components in addition to amorphous polymeric fibers. The amorphous polymeric fibers within the web may be autogeneously bonded or autogeneously bondable. The amorphous polymeric fibers may be characterized as varying in morphology over the length of continuous fibers so as to provide longitudinal segments that differ from one another in softening characteristics during a selected bonding operation.

Abstract: A new fiber-forming method, and related apparatus, and webs prepared by the new method and apparatus are taught. In the new method a) a stream of filaments is extruded from a die of known width and thickness; b) the stream of extruded filaments is directed through a processing chamber that is defined by two narrowly separated walls that are parallel to one another, parallel to said width of the die, and parallel to the longitudinal axis of the stream of extruded filaments; c) the stream of filaments passed through the processing chamber is intercepted on a collector where the filaments are collected as a nonwoven fibrous web; and d) a spacing between the walls of the processing chamber is selected that causes the stream of extruded filaments to spread before it reaches the collector and be collected as a web significantly wider in width than the die. Generally the increase in width is sufficient to be economically significant, e.g., to reduce costs of web manufacture.

Abstract: Nonwoven fibrous webs including amorphous polymeric fibers with improved and/or more convenient bondability are disclosed. The nonwoven fibrous webs may include only amorphous polymeric fibers or they may include additional components in addition to amorphous polymeric fibers. The amorphous polymeric fibers within the web may be autogeneously bonded or autogeneously bondable. The amorphous polymeric fibers may be characterized as varying in morphology over the length of continuous fibers so as to provide longitudinal segments that differ from one another in softening characteristics during a selected bonding operation.

Abstract: Nonwoven fibrous webs comprise fibers of uniform diameter that vary in morphology along their length. The variation provides longitudinal segments that exhibit distinctive softening characteristics during a bonding operation. Some segments soften under the conditions of the bonding operation and bond to other fibers of the web, and other segments are passive during the bonding operation. Webs as described can be formed by a method that comprises a) extruding filaments of fiber-forming material; b) directing the filaments through a processing chamber in which the filaments are subjected to longitudinal stress; c) subjecting the filaments to turbulent flow conditions after they exit the processing chamber; and d) collecting the processed filaments; the temperature of the filaments being controlled so that at least some of the filaments solidify while in the turbulent field.

Abstract: A new fiber-forming method, and apparatus useful for performing the method, are taught in which extruded filaments of fiber-forming material are directed through a processing chamber that is defined by two parallel walls, at least one of which is instantaneously movable toward and away from the other wall; preferably both walls are instantaneously movable toward and away from one another. Movement means provide instantaneous movement to the at least one movable wall. In one embodiment, the movement means comprises biasing means for resiliently biasing the wall toward the other wall. Movement of the wall toward and away from the other wall is sufficiently easy and rapid that the wall will move away from the other wall in response to increases in pressure within the chamber but will be quickly returned to its original position by the biasing means upon resumption of the original pressure within the chamber.

Abstract: New fibrous nonwoven webs are taught that comprise a mass of polyethylene terephthalate fibers that exhibit a double melting peak on a DSC plot: one peak is representative of a first molecular portion within the fiber that is in non-chain-extended crystalline form, and the other peak is representative of a second molecular portion within the fiber that is in chain-extended crystalline form and has a melting point elevated over that of the non-chain-extended crystalline form. Webs comprising fibers having such a morphology have a unique combination of durability and dimensional stability. The fibers are generally autogenously bonded at points of fiber intersection.

Abstract: A sorptive article is provided. The sorptive article includes a polyolefin, a wax which is miscible with the polyolefin at the melt temperature of the polyolefin but phase separates on cooling of the article, and sorptive particles distributed in the article. Also provided is a method for removing moisture or other vaporous or liquid material from air or an object in the environment utilizing a novel sorptive article of the invention.

Abstract: Fibrous webs of bicomponent fibers are made by extruding a layered molten mass through a row of side-by-side orifices into a high-velocity gaseous stream. Bicomponent fibers of small size can be obtained, and the webs offer unique properties.

Abstract: A microporous shaped article is provided. The article comprises ethylene-vinyl alcohol copolymer which has an internal structure of a multiplicity of spaced, randomly dispersed, non-uniform shaped particles of ethylene-vinyl alcohol copolymer.

Abstract: The present invention provides a method of modifying the surface of a polymeric substrate, e.g., to improve the wettability of the polymer film surface and/or affix silicon-containing structures to the substrate surface, comprising exposing the substrate to a flame. The flame is supported by a fuel and oxidizer mixture that includes at least one silicon-containing compound that functions as a fuel and is in an effective amount for modifying the surface of the polymeric substrate. Also disclosed are substrates with surfaces that are modified by exposing the substrate to a flame that is supported by the process of the invention. Large increases in the ASTM wetting test, e.g., greater than 13 mJ/m.sup.2 over that reported with conventional flame-treating processes, have been observed in polymeric substrates treated according to this invention.

Abstract: The present invention provides a method of modifying the surface of a polymeric substrate, e.g., to improve the wettability of the polymer film surface and/or alter the reactivity of the surface of the substrate by further oxidation, comprising exposing the substrate to a flame. The flame is supported by a fuel and oxidizer mixture that includes an effective amount, for modifying the polymeric substrate, of at least one oxygen-containing compound that functions as a fuel substitute. Oxygen comprises between about 10 and 50 atomic percent of the compound. Large increases in the ASTM wetting test over that reported with conventional flame-treating processes, have been observed in films treated according to this invention. In addition, significant increases in polymer film surface oxidation levels have been observed.

Abstract: A composition comprising: (1) a susceptor of magnetically coupled radio frequency energy comprising a non-magnetic particulate substrate, e.g., an electrically insulative material in particulate form, bearing a thin magnetic coating, e.g., a magnetic inorganic film, and (2) a matrix that is substantially non-reflective of radio frequency energy, e.g., silicone rubber, which matrix can be heated upon the composition's being subjected to magnetically coupled radio frequency energy. It has been discovered that thin magnetic coatings on non-magnetic particles provide energy transfer with induction heaters equal to or better than many commonly used solid susceptor particles. It has also been discovered that the temperature of the composition of this invention can be regulated so as not to exceed a predetermined temperature.

Abstract: A polymerization process produces polymers that are insoluble in a reaction mixture that was homogeneous before the polymer began to form. A dispersing agent in the polymerizing system (i.e., the reaction mixture plus the dispersing agent) allows a kinetically stable dispersion of the polymer to be formed in this polymerizing system. The polymerization process is performed in a fluid held under superatmospheric conditions such that the fluid is a liquid or a supercritical fluid; the fluid being carbon dioxide, a hydroflurocarbon, a perfluorocarbon, or a mixture of any of the foregoing.

Abstract: The present invention provides a method of modifying the surface of a polymeric substrate, e.g., to improve the wettability of the polymer film surface and/or alter the reactivity of the surface of the substrate by further oxidation or affixation of nitrogen, comprising exposing the substrate to a flame. The flame is supported by a fuel and oxidizer mixture that includes an effective amount, for modifying the polymeric substrate, of at least one compound that functions as a fuel or oxidizer substitute and is selected from an oxygen-containing compound, in which the oxygen comprises between about 10 and 50 atomic percent of the compound, a nitrogen-containing compound or an oxygen-nitrogen-containing compound. In a preferred embodiment, which affixes nitrogen or nitrogen-containing chemical groups onto the surface of the film, the flame is supported by a fuel and oxidizer mixture that includes ammonia, nitrous oxide, nitric oxide or a mixture thereof in an effective amount.

Abstract: A hydrophilic porous article is provided. The article comprises a hydrophobic porous substrate having coated on at least one external surface and on the internal surface a polyamide. Also provided is a method for making the hydrophilic porous article comprising forming a solvent solution of polyarnide in calcium chloride and methanol; treating a hydrophobic porous substrate by applying the solution to the substrate; rinsing the treated substrate with water to remove the calcium chloride and methanol; and drying the treated substrate.

Abstract: Spindle-shaped goethite particles are produced by oxidizing a ferrous carbonate intermediate in the presence of a growth modifier, or alternatively by changing the flowrate of oxidizing gas during oxidation. The goethite particles thus produced have a narrow size distribution, high aspect ratio and are substantially dendrite-free. These properties make the inventive goethite particles suitable for use in preparation of high density magnetic recording media.

Abstract: A method of preparing a porous article is provided. The method includes: contacting a porous substrate with a first reactant that enters pores of the substrate; and contacting the porous substrate bearing the first reactant with a second reactant that is capable of reacting with the first reactant in an interfacial polymerization reaction; the amounts of first and second reactant being selected such that there occurs no, or substantially no, closing of pores of the substrate by the formed polymer. The invention also provides a porous article bearing a compound which is photochemically reactive and capable of undergoing a substantially non-reversible chemical transformation upon exposure to ultra-violet, visible or near infra-red irradiation. The photochemically reactive compound can be derivatized by irradiation and further reaction to provide a wide variety of useful membranes, for example, for microfiltration or for biochemical reactions and separations.