Abstract: A system produces segmented tubular products such as filters from nonwoven fibers and includes a die assembly, a collector assembly including a rotating mandrel, a withdrawer assembly, and a post-treatment assembly. The withdrawer assembly utilizes at least one threaded roller contacting either the inner or outer periphery of a tube formed on the mandrel to withdraw the tube from the mandrel in a controlled manner. The post-treatment assembly smoothes the outer surface of the tube prior to cutting by melting loose fiber strand strands extending therefrom. The properties of the finished product can be varied by altering the operation of the collector assembly and/or the withdrawer assembly.

Abstract: A cylindrical filter formed of stacked microfine, conjugate fibers consisting of a higher melting point component and a lower melting point component, the fiber diameter of the conjugate fibers being varied into a smaller one in the thickness direction of the filter and along with the passing direction of a fluid to be filtered, and the contact points of the conjugate fibers being melt-adhered by the lower melting point component is provided.

Abstract: Meltblown thermoplastic fibers are cooled by microsized water droplets produced by airless ruby nozzles. The droplets have an average diameter of less than 20 microns.

Abstract: An improved process and apparatus are provided for the formation of a spun-bonded fibrous web suitable for service in nonwoven end uses. A melt-processable thermoplastic polymeric material is melt-extruded to form a multifilamentary spinline, is quenched, and is wrapped about at least two spaced driven draw rolls that are surrounded by a shroud prior to collection to form a web, and is bonded to form a spun-bonded nonwoven product. The draw rolls exert a pulling force on the multifilamentary spinline so as to accomplish drawing of the molten multifilamentary spinline prior to complete solidification. The shroud makes possible the self-stringing of the spinline around the draw rolls. A pneumatic jet located at the exit end of the shroud assists in the contact of the multifilamentary spinline with the draw rolls in order to facilitate the imposition of a uniform pulling force and expels the multifilamentary spinline in the direction of its length toward a support where it is collected.

Abstract: A topsheet of body fluid absorptive articles comprising a first sheet made of thermoplastic synthetic resin sheet and having liquid passages each downwardly extending therethrough and a second sheet containing 70 to 100% by weight of cellulose fibres bonded to said first sheet around lower openings of the respective liquid passages and comprises mechanically intertwined fibres only. The second sheet has a density higher than a density of fibres contained in the liquid-absorbent core.

Abstract: Apparatus and methods are disclosed whereby elongate preformed thermoplastic elements are friction-welded coaxially in an end-to-end manner so that the core elements are joined integrally to one another. Most preferably, the elongate elements are perforated tubular elements formed of a thermoplastic material which are employed as core elements in the production of cylindrical melt-blown filter cartridges. As such, the integrally joined core elements can be rotated and traversed as a unit relative to a melt-blowing die during the continuous production of indefinite length cylindrical melt-blown filter cartridges.

Abstract: A nonwoven disposable face mask includes a filtration layer formed of a plurality of thermoplastic microfine meltblown microfibers having an average fiber diameter of less than 1.5 microns. The filtration layer also has a basis weight of less than ten grams per square meter. The resultant face mask provides improved wearer comfort and barrier and filtration properties.

Abstract: Disclosed is a drawn, polyolefin fiber useful for nonwoven fabrics, the thermobonding index of said fiber being 4.5-9 Newtons, and the flexibility index thereof being 1020-1500. The fiber is composed of a blend of specified polymers. Also disclosed is a process for making the fiber by spinning the blend from a die hole having at the output end a diameter less than 0.5 mm, and drawing the resulting fiber at a draw ratio of 1.1 to 1.8.

Abstract: A topsheet for use in body fluid absorptive articles is so improved that collapse and clogging of liquid passages therein may be reliably avoided. The topsheet includes an upper sheet, provided with skin-contacting areas and liquid passages, and a lower sheet provided with skin-non-contacting areas, areas welded to the liquid passages, and exposed areas. The exposed areas are welded to each of the liquid passages around lower openings thereof so as to protect the liquid passage against collapse and clogging. The exposed areas define a skin-contacting surface which rises up into each of the liquid passages without extending above the upper surface of the skin-contacting areas. The upper sheet cooperates with the lower sheet to define cavities extending in the direction of the topsheet thickness.

Abstract: Conductive meltblown fabrics are disclosed which have improved strength and hand over conventional conductive meltblown fabrics. Also disclosed is a process for spraying a solution containing a conductive agent into a molten stream of meltblown fibers before they are deposited onto a forming wire. By applying the solution onto the fibers before they are deposited onto the forming wire, the heat of the molten stream vaporizes the solvent carrying the conductive agent and thereby eliminates the need to subsequently dry the formed material. By eliminating the drying step, degradation of the strength and hardening of the hand of the material normally resulting from the wetting and drying of meltblown fabrics are avoided. There is also disclosed a conductive SMS laminate having a conductive meltblown layer sandwiched between two untreated and nonconductive spunbond layers.

Abstract: A fiberglass product usable as an end product or an intermediate product is formed as a pack in a forming station but only 1/7th of the conventional quantity of binder is applied. After curing to a self-sustaining form, additional binder is added in an amount in excess of the amount required in the final product and then the excess binder and moisture is removed by one or more stripping steps. Additional moisture is removed by electronic means to the desired moisture level for commercial products.

Abstract: A patterned nonwoven fabric comprising polymeric strands which include a primary polymeric component and are bonded together without the use of compression, but instead with a heat activated adhesive polymeric component which adheres the respective primary components together. The fabric has an embossed pattern of densified areas separated by high loft areas. Preferably, the strands are continuous, crimped, multicomponent filaments. Also preferably, the nonwoven fabric is laminated to a liquid barrier film to form an outercover material for products such as personal care absorbent articles, and the like. Methods for making these materials are also encompassed.

Abstract: The present invention provides a method of making an orthopedic casting article comprising an apertured, extruded sheet. The method involves the steps of charging an extrudable material selected from the group consisting of low temperature thermoplastic polymers and viscous curable resins to an extruder; and extruding the material through a die to form an apertured sheet. The sheet is used as an orthopedic casting material and has a sufficient number of apertures after application to the patient to allow moisture vapors produced by the skin to freely escape through the cast or splint. The sheet preferably has at least 20 percent aperture volume. The apertured, extruded sheet may optionally contain a filler associated with the resin. The incorporation of fillers adds substantially to the strength of the cured casting material as well as to the handling properties of the uncured casting tape or bandage.

Abstract: Nonwoven material comprising a web of spunbonded polymer filaments in combination with at least one other spunbond or meltblown nonwoven layer with the combination impregnated with a stabilizing agent and the spunbond layer having been hot calendered to improve surface abrasion resistance. Preferred embodiments using a coating bath also including a surfactant and smooth calendering.

Abstract: A composite includes a first substrate, a second substrate, a third substrate and a discontinuous adhesive structure disposed intermediate the first and second and the second and third substrates for securing the first, second and third substrates together to form a composite without significantly modifying the properties of any of the substrates. The discontinuous adhesive structure is an array of substantially linear filaments or strands of an adhesive. The composite combines high moisture vapor transmission, high resistance to penetration by liquids and high resistance to viral penetration even at a pressure of at least 3 psi, thereby rendering it suitable for medical applications such as surgical gowns, etc.

Abstract: Multiconstituent fibers prepared from two or more polymers, with at least one of these polymers being randomly dispersed through the fiber, in the form of domains. At least about 40 percent by weight of these domains have one length of at least 20 microns, measured in the direction along the fiber axis, and have another length, measured along the longest line dissecting the domain cross-section in a plane perpendicular to the fiber axis, of at least about 5 percent of the fiber equivalent diameter.

Abstract: A shaped nonwoven fabric comprises continuous spunbond filaments made by directly forming the spunbond filaments into a web in a single process. The fabric has an array of discrete surface features such as apertures or projections, or both. The spunbond filaments are bonded together with an adhesive polymeric component so that the shape of the fabric is retained. The fabric can be engineered to have particular fluid handling properties, strength properties, abrasive properties and aesthetic properties. Articles such as personal care products, garments, medical products and cleaning products are also disclosed.

Abstract: A composite includes a first substrate, a second substrate, and a discontinuous adhesive structure disposed intermediate the first and second substrates for securing the first and second substrates together to form a composite without significantly modifying the properties of either of the first and second substrates. The discontinuous adhesive structure is an array of substantially linear filaments or strands of an adhesive.

Abstract: A process for preparing an ignition resistant carbonaceous material by exposing a meltblown or spunbonded acrylic precursor material in the form of at least one ply of a generally planar fibrous web, matt or batt to ionizing radiation to crosslink said acrylic material which is then heat treated in an inert atmosphere to increase the carbon content of said irradiated material to form said carbonaceous material. The invention also resides in a continuous self bonded fibrous carbonaceous material having a carbon content of from about 65% to less than about 92%, an oxygen content of less than about 2%, and a specific resistivity of from about 10.sup.-1 to about 10.sup.-10 ohm-cm. Preferably said carbonaceous material has an oxygen content of less than about 1% and a nitrogen content of from about 5% to about 30%.

Abstract: Sheath-core bicomponent fibers comprising a core of a low-cost, high strength, thermoplastic material, preferably polypropylene, completely covered with a sheath formed preferably of plasticized cellulose acetate, ethylene-vinyl acetate copolymer, polyvinyl alcohol or ethylene-vinyl alcohol copolymer, are produced, preferably melt blown to an average diameter of 10 microns or less, and formed into tobacco smoke filters. The resultant filters retain the desirable taste properties and processing capabilities of conventional cellulose acetate filter elements, but are substantially less expensive. Because the core material is non-absorbent, less plasticizer or additive is required for comparable properties, and a web, roving or filter made of such materials has a longer shelf-life. The very fine fibers can be formed of various cross-sections, providing higher surface area and requiring less air in the melt blowing and manufacturing processes.

Abstract: A method of making a microfibrous sorbent article is provided. The method includes the steps of a) extruding molten thermoplastic fiber forming polymer from multiple orifices in a fiber-forming die, said orifices being aligned along the face of the die; b) attenuating the fibers in a stream of hot air to form a fiber stream of microfibers; and c) collecting said microfibers on a collector having a forming surface, said surface being aligned with said die and substantially parallel to and equidistant from said die such that the fibers form a spirally wound microfibrous sorbent article which is supported on its exterior surface by said forming surface and which is drawn across said forming surface substantially parallel to said die. Also provided is a microfibrous sorbent article prepared according to the method.

Abstract: A threadlike or ribbonlike elastic strand is provided with a substantially continuous filament of adhesive helically wrapped around the elastic strand. The elastic strand is suitable for use in disposable absorbent products such as diapers and adult incontinent products. Also disclosed is a method and apparatus for making such adhesive-wrapped elastic strands.

Abstract: A method of making a flexible fabric composed of a fibrous matrix of ribbon-like, conjugate, spun filaments. The method includes the following steps: 1) providing a fibrous matrix composed of individual, spun filaments bonded at spaced-apart bond locations, the filaments themselves being composed of: (i) a core formed of at least one low-softening point thermoplastic component; and (ii) a sheath formed of at least one high-softening point component; and 2) applying a flattening force to the fibrous matrix to durably distort the core of individual filaments into a ribbon-like configuration having a width greater than its height so that: (i) the individual filaments are substantially unattached between the spaced-apart bond locations, and (ii) the width of individual filaments is oriented substantially in the planar dimension of the fabric. Also disclosed is a flexible fabric composed of a fibrous matrix of ribbon-like, conjugate, spun filaments joined at spaced apart bond locations.

Abstract: The invention is directed to a composite nonwoven fabric comprising first and second nonwoven webs of spunbonded substantially continuous thermoplastic filaments, and a nonwoven hydrophobic microporous web of thermoplastic meltblown microfibers sandwiched between the first and second nonwoven webs. The filaments of the nonwoven spunbond webs are formed of continuous multiconstituent filaments which include a lower melting gamma radiation stable polyethylene polymer component and one or more higher melting gamma radiation stable polymer constituents, wherein a substantial portion of the surfaces of the multiconstituent filaments consists of the lower melting gamma radiation stable polyethylene constituent. The nonwoven hydrophobic microporous web is formed from a gamma radiation stable polyethylene polymer.

Abstract: A method for making a door mat comprising an integral mass of loops of synthetic resin monofilaments which includes a surface layer having a decorative pattern on its upper side and a reverse surface layer having its upper side joined to the lower side of said surface layer. The underside of the reverse surface layer may be joined to an anti-slip layer, which may be in the form of a lattice layer.

Abstract: There is disclosed a novel apparatus and process for melt-blowing fiberforming thermoplastic polymers to form fine fibers by extruding through spinning nozzles arranged in four or more rows. The molten fibers are accelerated to near sonic velocity by gas being blown in parallel flow through small circular gas orifices surrounding each nozzle. The air orifices are formed by a family of plates which effect the perfect centering of each nozzle in each of the circular air orifices.

Abstract: An improved reinforced laminate for use in sails or other flexible sheet or membrane applications utilizes a pull-truded thin lightweight reinforcing sheet of unidirectional extruded monofilaments in which the reinforcing sheet or sheets form one or more uni-tapes laminated to a polymer film such as Mylar, or other extended sheet of material. The monofilaments are uniformly embedded in the uni-tape via an elastomeric polymer matrix, with the reinforcing sheet, when incorporated into sails via lamination resulting in sails with reinforcing monofilaments having diameters 5 times less than conventional strands or threads. The use of small diameter monofilaments greatly increases the monofilament-over-monofilament crossover density, resulting in a dramatic increase in shear strength, and Youngs' Modulus, with an accompanying dramatic decrease in weight. In one embodiment the improvement in specific modulus over conventional sail laminates is about six-fold.

Abstract: A method for producing a mat including a three dimensional filament loop aggregate comprises extruding molten thermoplastic synthetic resin die to form a plurality of filaments. The filaments are heated and descend onto a surface of a cooling liquid, between a pair of rotatable rolls submerged in the cooling liquid. The filaments are all cooled simultaneously by the cooling liquid and form loops on the surface thereof. A first series of loops formed from outermost filaments are supported on one of the rotatable rolls in the cooling liquid, with the loops being horizontal. Rotation of the roll moves these loops into a vertical position. Thereafter, all the loops are integrated, with the loops formed by the outermost filaments being in a vertical position, and the loops formed by the remaining filaments being in the horizontal position.

Abstract: The present invention is directed to an absorbent article with a tissue-wrapped absorbent core wherein the tissue is made from a specifically designed thermoplastic fibrous nonwoven web which is particularly well-suited to trapping and retaining particulate material such as superabsorbent particles. The invention has particular application in conjunction with personal care products such as diapers, training pants, incontinence garments, sanitary napkins, bandages and the like.

Abstract: A multiplicity of closely spaced thermoplastic polymer filaments are extruded from an elongated orifice plate through a draft protected free-fall zone onto a rotating cylinder surface, landing between about 30.degree. before and after upper dead center of rotation. Filament extrusion velocity and cylinder rotational velocity are coordinated to pile the filament into a mat continuum of accumulated filament laps. Filament temperature and viscosity are coordinated to provide thermoplastic bonding at the filament lap crossings to integrate the continuum. The rotating cylinder carries the matted continuum over an arc of about 150.degree. to 210.degree. to about lower dead center of rotation where the mat peels from the cylinder surface. After separation from the cylinder surface, the mat is supported by a transitional air jet on to a horizontal run surface of a traveling endless belt for consolidated support until the lap crossing bond joints are securely set.

Abstract: Method and device for manufacturing a flat textile structure in which two melts of at least two polymer materials are changed to the form of fibers with the aid of a spinning device and in which fibers are then combined and then solidified. The spinning device consists of a spinning rotor and the polymer materials employed have an charge difference of at least ten unit charges. The two materials are first melted separately from one another. Each melt, by means of a distributor device, is then fed to a group of outlet openings of a spinning rotor unmixed. The fibers emerging from the outlet openings are then stretched and combined to form a common flat structure with the flat structure then being charged triboelectrically by an aftertreatment.

Abstract: A process for producing nonwoven webs having improved strength properties at high throughputs is provided. In the process, a non-uniform blend of a polyolefin and a prodegradant is formed. The non-uniform blend is then rapidly heated to cause the substantially immediate thermal degradation of the prodegradant, thus providing a non-uniformly degraded polyolefin having a fraction substantially reduced in molecular weight and a fraction substantially unaffected in molecular weight as compared to the starting polyolefin.

Abstract: Spunbonded nonwoven nylon fabrics are formed from a blend of nylon 6 and nylon 6,6 polymers. A blend or copolymer of 0.1 to 10 percent by weight of nylon 6, balance nylon 6,6 is extruded into continuous filaments, pneumatically attenuated and drawn, and deposited onto a collection surface forming a web. The web is bonded either chemically or thermally. The fabric exhibits improved filament bonding. The addition of nylon 6 also improves the spinning performance of a nylon 6,6 spunbonded nonwoven process.

Abstract: A cylindrical filter formed of stacked microfine, conjugate fibers consisting of a higher melting point component and a lower melting point component, the fiber diameter of the conjugate fibers being varied into a smaller one in the thickness direction of the filter and along with the passing direction of a fluid to be filtered, and the contact points of the conjugate fibers being melt-adhered by the lower melting point component is provided.

Abstract: Method and device for producing a flat textile structure in which a melt of a polymer material is changed to the form of fibers with the aid of a spinning rotor. The still sticky fibers are impacted with a mixture of hot gas particles; the particles are then ionized in a high-voltage electrical field for longer duration of the filter effect.

Abstract: A melt-extrudable thermoplastic composition is provided which includes a thermoplastic polyolefin and an additive system made up of a first component and a second component, in which (A) the first component is a defined polysiloxane polyether having a molecular weight of from about 350 to about 18,000 and which is present in an amount of from about 0.1 to about 3 percent by weight, based on the amount of thermoplastic polyolefin; and (B) the second component is a hydrophobic fumed silica, in which the weight ratio of the first component to the second component is in the range of from about 20 to about 300. Such composition yields, upon melt-extrusion, either nonwoven webs having significantly increased tensile strengths when compared to nonwoven webs prepared from the thermoplastic polyolefin alone, or wettable webs requiring an amount of first component which is significantly less than that required in the absence of the second component.

Abstract: The improved nonwoven fabric in an electret state is composed of monofilaments with an average fiber diameter of 0.5-100 .mu.m that are formed of a polymer composition containing no more than 1 mol % of polar groups; the fabric has a weight of 5-100 g/m.sup.2, a bulk density of 0.05-0.40 g/cm.sup.3 and an average surface charge density of at least 0.1.times.10.sup.-9 C/cm.sup.2. This nonwoven fabric is capable of efficient dust collection and its trapping ability is retained for a prolonged time even in a hot and humid condition. Also disclosed are a process for producing this nonwoven fabric, as well as a filtering and an air masking material which are composed of that nonwoven fabric.

Abstract: An apparatus and method for producing a meltblown continuous and seamless nonwoven tube is described. The apparatus comprises a meltblowing die for extruding two groups of polymer thermoplastic filaments onto a rotating mandrel to form a multilayer layer tube thereon. The tube is withdrawn from the mandrel by a rotating screw. The present apparatus is capable of producing nonwoven tubes having variable fiber diameters and/or composition in the radial direction, making them ideally suited for filtration purposes.

Abstract: A method of attenuating a molten thermoplastic polymer stream into polymer fibers for forming a non-woven fiber mat, and the non-woven fiber mat formed thereby. The method applying a gas stream to a molten polymer stream, and inducing a cyclic pulsation in the gas stream. The cyclic pulsation further comprises a discontinuous flow of the gas stream. The application of the gas stream to the molten polymer stream causes the attenuation of the molten polymer stream into a plurality of fibers which are collected onto a receiving surface thereby forming a non-woven fiber mat. The method may be used to impart a particularly unique or otherwise desirable configuration to the fibers or to the fiber mat produced from them. The gas stream may be comprised of a primary gas flow having a first stream and a second stream. The gas stream may be further comprised of a secondary gas flow having a first stream and a second stream.

Abstract: Reinforcing material which does not have a melting point which is compatible with the processing temperature of an elastomer can be incorporated into the elastomer in the form of melt blown fibers. In the method of the invention, melt blown fibers are made by melting a reinforcing material in an extruder, and extruding the reinforcing material through a die comprising many small holes, while simultaneously blowing air or nitrogen, under high pressure, through the die holes, and collecting the resulting material on rotating rolls. The fibers thus formed are mixed into an elastomer using conventional mixing means. A composite made by the method is also provided.

Abstract: A slot draw attenuator apparatus and method are provided for producing webs of spunbonded thermoplastic filaments having improved cover even at low basis weights. The filaments are introduced to a slot draw attenuator having corona electrodes mounted in an elongate insulator bar and staggered and spaced along one wall of the attenuator slot near the exit end thereof. The corona electrodes are electrically connected to a high voltage source. The opposing wall of the slot is grounded. A corona is created in the attenuator slot so that the filaments are charged as they exit the attenuator. The electrostatic charge induces repelling forces in the filaments so that the filaments spread before they are randomly deposited upon a forming belt.

Abstract: The core of a honeycomb panel consists of a set of corrugated strips each of which alternate abut the immediately adjacent strips. Interlocking protrusions are formed in the abutting portions of the strips. The protrusions provide automatic registration of the strips without jigging or fixturing. Preferably the protrusions are somewhat undercut to provide a detent or snapping action upon assembly to provide mechanical integrity prior to bonding. The snapping action also holds the abutting surface together for uniform bonding. Lateral registration of the strips can be provided by, for example, forming a lance and window or mating dimples in the abutting surfaces. Bonding of the abutting surfaces can be done by soldering, brazing, or gluing. This honeycomb core structure is suitable for the continuous fabrication of panels of arbitrary length, width, and thickness.

Abstract: Disclosed is an anisotropic elastomeric nonwoven fibrous web composed of a substantially homogeneous distribution of elastomeric meltblown fibers that are physically aligned along one of the planar dimensions of the web. The anisotropic elastomeric nonwoven web of meltblown fibers has a strength index of at least about 2. Also disclosed is process of making such an anisotropic elastomeric nonwoven web of meltblown fibers as well as a composite elastic material which contains an anisotropic elastomeric nonwoven web of meltblown fibers.

Abstract: Provided is a polyethylene terephthalate-based meltblown nonwoven fabric comprising a mixed polymer comprising 75 to 98% by weight of polyethylene terephthalate and 2 to 25% by weight of a polyolefin. The meltblown fabric has excellent thermal resistance, dimensional stability, strength and hand. Also provided is a process for producing a polyethylene terephthalate-based meltblown nonwoven fabric, which comprises melt blowing a mixed polymer comprising 75 to 98% by weight of polyethylene terephthalate and 2 to 25% by weight of a polyolefin. It is preferable that the melt blowing is conducted at a single orifice throughput of 0.2 to 1.0 g/min and under an air-jet pressure of 0.1 to 1.0 kg/cm.sup.2.

Abstract: Drawing, from a first installation, organic filaments in the form of one or more layers which converge toward a same point, and drawing, from a second installation, glass filaments which are joined together to form at least one strand. Guiding structure is provided to laterally introduce the glass strand into the area defined by the organic filaments before it is combined with the filaments at their point of convergence. A blowing device (48, 36) is also provided either outside or inside the area defined by the organic fibers.

Abstract: The invention is directed to elastomeric meltblown webs having desirable strength and stretch/recovery properties which can be produced at relatively high throughputs and/or relatively low die pressures. The meltblown webs of the invention comprise a blend of (i) a fully hydrogenated diblock or triblock thermoplastic elastomer copolymer or mixtures thereof based on polystyrene and poly(ethylene-butylene) blocks; and (ii) from about 5% by weight up to about 50% by weight of a copolymer of ethylene and acrylic acid or ethylene and a lower alkyl ester of acrylic acid in which the ethylene content ranges from about 5% by weight up to about 50% by weight.

Abstract: An elastic nonwoven web of microfibers of radiation crosslinked ethylene/alpha-olefin copolymers. The web has an elongation to break of at least 400 percent and generally is comprised of meltblown microfibers. The ethylene/alpha olefin is preferably an ethylene/1-octene copolymer having a density less than 0.9 g/cm.sup.3 and a melting point of less than 100.degree. C.

Abstract: An apparatus for manufacturing a strand composed of organic filaments and glass filaments for use in the production of composite materials. This apparatus comprises at least one die, which is supplied with molten glass, and at least one drawing head, which is supplied under pressure with organic thermoplastic material, and from which are simultaneously drawn continuous filaments that are combined to form a composite strand. The drawing head comprises a central passage through which filaments of glass are drawn, and is shielded by a hood. The top of the hood includes an opening situated in the centerline of the passage, and the bottom of the hood is formed of a wall which surrounds the drawing head and extends below the level of the bottom of the head. The drawing head is connected with a device for cooling the organic filaments.

Abstract: A non-woven fabric is characterized by including a filament layer in which one or more continuous filaments composed of a polymeric material are spirally collected substantially along a shape obtained by offsetting an ellipse having an elongated major axis in a plane. This non-woven fabric can be obtained by spinning a filament composed of a polymeric material, vibrating the filament, amplifying vibration of the filament, and collecting the filament into an elliptic shape having an elongated major axis so that the filament is arranged in a direction of the major axis.

Abstract: Controlled porosity composite sheets comprising a melt-blown polypropylene fiber web having a spunbonded polypropylene fiber sheet laminated to at least one side thereof are made by calendering an assembly of the component webs in such a manner that, when a two-layer composite sheet is made, the web of melt-blown fibers is in contact with a metal roll heated to 140.degree.-170.degree. C. operating against an unheated resilient roll; and, when a three-layer composite sheet is made, the spunbonded web in contact with the heated metal roll has a dtex per fiber value of less than 6.These composite sheets have a Gurley-Hill porosity of about 5-75 seconds, excellent mechanical and tear strengths, high water vapor penetration rate, and low liquid water permeability. They are particularly suitable for making housewrap sheets and sheets for sterile packaging. In the sterile packaging field, they are significantly better than medical paper used for the same purpose.