1993 results about "Fiber diameter" patented technology

An electret filter media, and mask, that is made of a nonwoven web of thermoplastic microfibers. The thermoplastic microfibers are of substantially the same composition, are nonconductive, and have an effective fiber diameter less than about 15 micrometers. The nonwoven web also has sufficient unpolarized trapped charge to exhibit an initial filtration quality factor of at least 0.31 when measured under the DOP Penetration and Pressure Drop Test.

This invention relates to a process of melt blowing a cellulose solution through a concentric melt blown die with multiple rows of spinning nozzles to form cellulosic microfiber webs with different web structures. The process comprises the steps of (a) extruding a cellulose solution (dope) through a melt blown spinneret with multiple rows of spinning nozzles; (b) drawing each individual extrudate filament to fine fiber diameter by its own air jet; (c) coagulating and entangling the fine fibers with a series of pressured hydro needling jets of recycling solution of the mixture of cellulose solvent and non-solvent in the spin-line; (d) collecting the stream of microfibers, air and needling jets on a moving collecting surface to form cellulosic fiber web; (e) hydro-entangling the said pre-bonded web downstream with at least one set of hydro needling jets of recycling solvent/non-solvent solution for forming well bonded nonwoven web; (f) regenerating the fine fibers in at least one bath for at least 5 seconds; (g) further regenerating and washing the fine fibers in another bath for at least 5 seconds; (h) pinching the well bonded melt blown cellulosic nonwoven with pressure rollers to remove major portions of the non-solvent; (i) drying the nonwoven web by heat, or vacuum or both, and (j) winding the nonwoven web into rolls.

Vacuum heat insulator comprising a laminated core made of a plurality of sheets of inorganic fibers having 10 μm or smaller in diameter and a certain composition including SiO₂ as a main component, Al₂O₃, CaO, and MgO, a gas barrier enveloping member, and an absorbent. The vacuum heat insulator is characterized by having at least one groove formed therein after fabrication of the vacuum heat insulator. Further, the vacuum heat insulator is characterized by using inorganic fiber core of which a peak of distribution in fiber diameter lies between 1 μm or smaller and 0.1 μm or larger, and not containing binding material for binding the fiber material. Electronic apparatuses use the vacuum heat insulator. With use of the vacuum heat insulator, electronic and electric apparatuses superior in energy saving and not to present uncomfortable feeling to the user can be provided.

The present invention relates to an acoustical insulation material containing a first layer formed from a nonwoven web having a density of at least 50 kg/m³ wherein the nonwoven web is formed from thermoplastic [meltblown] fibers having an average fiber diameter of less than about 7 microns; and a second layer of a high loft material. The high loft material of the present invention provides bulk to the first layer and may or may not have sound attenuating properties. Examples of the high loft material include, for example, fiberglass and high loft nonwoven webs. Also disclosed in a method of attenuating sound waves passing from a sound source area to a second area. The method includes positioning an acoustical insulation material containing a first layer formed from a nonwoven web having a density of at least 50 kg/m³ wherein the nonwoven web is formed from thermoplastic [meltblown] fibers having an average fiber diameter of less than about 7 microns; and a second layer of a high loft material, between the sound source area and the second area.

The nozzle piece of the present invention is provided with circular cross sectional nozzles having different sizes disposed in a row in front of the die, with n-numbered smaller nozzles B (hole diameter: Db) between adjacent larger nozzles A (hole diameter: Da). It gives melt-blown non-woven fabric of monolithic structure in one step, composed of fine fibers having a diameter in a range from 1 to 10 mum diameter Variance ratio F of 2.0 or more and wide fiber diameter distribution.

A high efficiency filtration medium comprised of a nonwoven filter web of electret charged fibers of a nonconductive thermoplastic resin having a resistivity greater than 1014 ohm-cm, preferably polypropylene. The nonwoven filter web has a basis weight (BW) of less than 60 grams/m2, an effective fiber diameter (EFD) of less than 5 microns and a penetration (PEN) of less than 0.03%, wherein the ratio); BW/(EFD.PEN) is greater than 200. The invention filter medium can be easily used in applications requiring HEPA performance at relatively low pressure drops.

A suturable adhesion-preventing membrane has high suture strength, good biocompatibility, decomposition and absorption in a living body, sufficient adhesion-preventing effect, and desirable guided tissue regeneration. The membrane is composed of at least one non-woven fabric layer made of collagen fibers, or a laminated membranous substance consisting of at least one non-woven fabric layer made of collagen fibers and at least one sponge layer made of collagen, and a coating layer of gelatin or hyaluronic acid on the surface or surfaces of the above membrane. Preferably, the membrane comprises one to six compressed cross-linked collagen non-woven fabric layers wherein a layer has a fibers having a fiber diameter of 0.05 mm to 1.0 mm, a bulk density of 5.0×10⁻⁴ to 5 g/cm³ and a thickness of 0.1 mm to 50 mm, and a coating layer containing gelatin or hyaluronic acid and having a thickness of 0.05 mm to 20 mm, wherein the coating layer covers one or both sides or a part or whole of the surface of the membrane.

A coalescing filtration medium is disclosed for removing liquid aerosols, oil and/or water from a gas stream. The medium contains a nanofiber web of at least one nanofiber layer of continuous, substantially polyolefin-free, polymeric nanofibers, each nanofiber layer having an average fiber diameter less than about 800 nm and having a basis weight of at least about 2.5 g/m².

The present invention is directed to a method of forming nonwoven webs comprising coated fibers. The method of forming the nonwoven web generally comprises the steps of forming fibers from a melt fibrillation process, forming at least one fluid stream containing a coating substance, applying the coating substance onto the surface of the fiber, and depositing the coated fibers on a surface to form a web. Typically, the fibers are coated in flight. Preferably, the melt fibrillation process to form the fibers is a melt film fibrillation process. A melt film fibrillation process generally includes the steps of providing a polymeric melt, utilizing a central fluid stream to form an elongated hollow polymeric film tube, and using air to form multiple nanofibers from the hollow tube. The nonwoven web may comprise a layer having a significant number of nanofibers with diameters less than one micron. The layer may comprise two or more pluralities of fiber diameter distributions wherein at least one plurality has an average fiber diameter of less than about one micron. The coating substance can be selected from the group consisting of lotions, powders, surfactants, softeners, nanoparticles, creams, gels, conducting fluids, hydrophilic agents, hydrophobic agents, hygroscopic agents, emollients, plasticizers, absorbent gelling material, antimicrobial agents, and combinations thereof. A preferred coating substance is a surfactant. Another preferred coating substance is a hydrophilic or hydrophobic substance. The present invention is also directed to a nonwoven web comprising a layer having a significant number of nanofibers with diameters less than one micron and a coating substance is applied to a surface of said nanofibers

A filter media comprising a nanofiber layer and a substrate layer; the nanofiber layer comprising a polymer material and having a fiber diameter of about 0.01 to 1.0 micron, a basis weight of about 0.5 to 30 gsm, and a thickness of at least about 2 microns, the nanofiber layer further having a surface stability index of at least about 5 kN/m, the media further being pleated.

Provided is a vacuum heat insulating material, using inorganic fibers as a core material, high in heat insulating performance (low in thermal conductivity), capable of maintaining the heat insulating performance for a long period, free of defects such as projections and depressions on a large scale on a surface thereof, short in manufacturing time and advantageous in terms of cost; and a manufacturing method therefor. A vacuum heat insulating material of the present invention is of a construction in which a core material 1 and a gas adsorbent 2 are housed in a bag 3 made from a gas barrier film and the interior thereof is reduced in internal pressure thereof and air-tightly sealed, wherein the core material 1 is a molded product obtained by coating a binder B on inorganic fibers having an average fiber diameter in the range of from 3 to 5 mum at a coating amount in the range of from 0.5 to 1.5 wt % relative to the fibers and heat pressing the inorganic fibers, or a laminate fabricated by stacking two or more sheets of the molded product.

A vacuum heat insulator according to the present invention includes a core molded to be plate-shaped with the use of a binding agent. The vacuum heat insulator assumes any one of the following configurations. A) The core is formed by curing a fiber aggregate by means of a binding agent. The fibers have an average fiber diameter of at least 0.1 μm but at most 10 μm, and voids defined by fibers have a void diameter of at most 40 μm. The core has a percentage of the voids of at least 80%. B) The binding agent is varied in concentration in a through-thickness direction of the core. C) A cured layer solidified by the binding agent is formed on at least one side surface of the core. D) The core contains fibers having a length of at most 100 μm. The fibers are oriented perpendicular to a direction of heat transmission. Such vacuum heat insulator is excellent in adiabatic property. Refrigerators, to which such a vacuum heat insulator is applied, are made small in size, or have a large inner volume, or contribute to energy saving.

Disclosed is a cellulose nonwoven fabric containing cellulose fibers having a maximum fiber diameter of not more than 1500 nm and a crystallinity determined by solid state NMR techniques of not less than 60%. The porosity of the cellulose nonwoven fabric is not less than 40% and not more than 99%.

Disclosed is a highly transparent fiber-reinforced composite material including an assembly of cellulose fibers of 4 to 200 nm average fiber diameter impregnated with a matrix material so as to not only remedy the moisture absorbency attributed to cellulose fibers but also further improve transparency. There is provided a fiber-reinforced composite material including an assembly of cellulose fibers impregnated with a matrix material. In the fiber-reinforced composite material, hydroxyl groups of cellulose fibers are chemically modified through a reaction with one or more chemical modifiers selected from the group consisting of an acid, an alcohol, a halogenating reagent, an acid anhydride, and an isocyanate so that the ratio of a functional group introduced by the chemical modification is 5 to 40 percent by mole based on the hydroxyl groups of cellulose fibers before the chemical modification. The chemical modification of hydroxyl groups of cellulose fibers can reduce the hydrophilicity of cellulose fibers to thereby reduce the moisture absorbency of fiber-reinforced composite material. Further, the affinity between cellulose fibers and matrix material can be enhanced to thereby further improve transparency.

Various high performance, high efficiency, long service interval air filter media that are cost effective and easy to manufacture are provided. The filter media of the present invention can have at least two layers comprising blends of binder and non-binder fibers that are thermally bonded to one another and set to caliper in a high velocity forced draft oven. The layers can also be subsequently resin saturated, dried, and optionally cured. The resulting media can be characterized as having a gradient in properties such as fiber composition, fiber diameter, solidity, basis weight, and saturant content.

An absorbent article may comprise a barrier component, the barrier component may comprise a nonwoven barrier sheet, the nonwoven barrier sheet may comprise a spunbond nonwoven web comprising spunbond fibers, and the nonwoven barrier sheet may further comprise a meltblown nonwoven web comprising meltblown fibers. The spunbond fibers may have a number average fiber diameter of from about 6 to about 18 microns. The meltblown fibers may have a number average fiber diameter from about 1 to about 5 microns. And, the total weight percentage (by basis weight of the nonwoven barrier sheet) of the meltblown web may be from about 5% to about 30%.

An antimicrobial, dustproof fabric includes a textile material layer which is composed of microfibers with an average fiber diameter of from 1 to 100 μm and contains an inorganic porous substance, and a nanofiber nonwoven fabric layer which is laminated on the textile material layer and has an average fiber diameter of at least 1 nm but less than 1,000 nm. Hygienic products such as masks obtained using the fabric efficiently block microbes such as viruses, and inactivate or destroy the captured microbes.

A nonwoven fabric composed of ultra-fine continuous fibers having a mean fineness of not more than 0.5 dtex is prepared. The nonwoven fabric comprises a water-soluble thermoplastic resin in a proportion of not more than 5% by weight relative to the nonwoven fabric, has an absorbing height of not less than 30 mm as determined at 20° C. after 10 minutes based on Byreck method when the nonwoven fabric immersion-treated for 60 minutes in a water of 80° C. is used, and satisfies the following formula: (B)/(A)≧0.25, wherein the symbol (B) represents a tensile strength [N/5 cm] in the longitudinal direction and the lateral direction of the nonwoven fabric and the symbol (A) represents a fabric weight [g/m] of the nonwoven fabric. In the nonwoven fabric, not less than 30% of the surface may be coated with the water-soluble thermoplastic resin. The water-soluble thermoplastic resin may be a water-soluble thermoplastic polyvinyl alcohol, e.g., a modified polyvinyl alcohol containing an ethylene unit in a proportion of 3 to 20 mol %. The present invention provides a nonwoven fabric composed of ultra-fine continuous fibers, having a high flexibility or softness, and having a high mechanical strength even when the fiber diameter is small, and having an excellent water absorbency, as well as a production process and an application thereof.

Filter media, including those suitable for hydraulic applications, and related components, systems, and methods associated therewith are provided. The filter media described herein may include two or more layers, at least one of the layers having a relatively high percentage of microglass fibers. Additionally, the filter media may be designed such that the ratio of average fiber diameters between two layers is relatively small, which can lead to a relatively low resistance ratio between the layers. The filter media has desirable properties including high dirt holding capacity with low basis weight and a low resistance to fluid flow. The media may be incorporated into a variety of filter element products including hydraulic filters.

The present invention provides a medical adhesive tape or sheet having a superior texture, which can be easily cut with hands to form a good cross-section. The medical adhesive tape or sheet of the present invention is characterized in that it comprises a support, which is a multi-layer laminate of non-woven fabrics having different fiber diameters and treated with a sealer, and an adhesive layer laminated on one surface of the support, wherein at least the support is perforated, the perforation forms plural pores sequenced at least in one direction, the ratio (b/a) of interval a of the perforated part and interval b of the non-perforated part in one direction is 1-1.5, and the ratio (c/d) of the tensile strength c in the longitudinal direction and the tensile strength d in the width direction is 0.8-1.7. Consequently, a medical adhesive tape or sheet having a superior texture, which can be easily cut with hands to form a good cross-section without using a cutting tool such as scissors and the like is provided.