4162results about "Stretch-spinning methods" patented technology

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.

A lyocell nonwoven fabric having fibers characterized by pebbled surfaces and variable cross sections and diameters along the fibers and from fiber to fiber, is disclosed. The lyocell nonwoven fabric is produced by centrifugal spinning, melt blowing or spunbonding. The lyocell nonwoven fabric has fibers that can be made in the microdenier range with average weights as low as one denier or less. The lyocell nonwoven fabric has fibers with low gloss, a reduced tendency to fibrillate and have enhanced dye receptivity.

A low profile resorbable stent comprising an oriented, resorbable material, wherein said material has Young's Modulus and tensile strength in the oriented state greater than Young's modulus and tensile strength of unoriented material is disclosed. The low profile resorbable stent has a resorbable material with Young's modulus about 2-300 GPa and/or tensile strength 50-200 MPa. The resorbable material of the present invention is oriented such that the tensile strength and modulus are higher than the unoriented materials allowing for the low profile stent design. Also disclosed is a method of manufacturing a low profile resorbable stent. The method comprises providing an extrudate comprising a resorbable material, inducing molecular alignment in the extrudate to form an oriented extrudate and forming the stent from the oriented extrudate. The extrudate of resorbable material can be a sheet, tube or some other form. The sheet extrudate is stretched axially or biaxially to induce molecular alignment. The tubular extrudate is blow-molded to induce molecular alignment.

Disclosed are a graphene composite nanofiber and a preparation method thereof. The graphene composite nanofiber is produced by dispersing graphenes to at least one of a surface and inside of a polymer nanofiber or a carbon nanofiber having a diameter of 1˜1000 nm, and the graphenes include at least one type of monolayer graphenes, and multilayer graphenes having a thickness of 10 nm or less. The graphene composite nanofiber can be applied to various industrial fields, e.g., a light emitting display, a micro resonator, a transistor, a sensor, a transparent electrode, a fuel cell, a solar cell, a secondary cell, and a composite material, owing to a unique structure and property of graphene.

Improved polymeric endoprostheses and methods of manufacturing endoprostheses are disclosed herein. The endoprostheses may comprise one or more polymers wherein the polymer chains are substantially aligned circumferentially, and comprising increased radial strength and flexibility. An endoprosthesis according to the invention may comprise a smooth surface. Endoprostheses disclosed herein may be used in the treatment of strictures in lumens of the body. Alternatively, endoprostheses disclosed herein may be used as anchors to secure medical devices within lumens of the body. The endoprostheses disclosed herein may comprise one or more erodible polymer.

A film for use in absorbent articles is first microscopically textured and then macroscopically apertured while maintaining the microscopic texture. The micro-texturing may be done by a variety of means including vacuum forming, and may include micro-apertures. The macroscopic texture may be done by a variety of means including thermo-mechanical means with a heat shielding means. Where heated pins are used, the heat shielding means protects the micro-texture from the heat so that the heat does not deform the micro-texture.

A dryer operable in close proximity to and in series with an inkjet printhead comprises a heat source and an air bearing structure on one side of the predetermined path and having a pressurized air inlet and an air outlet adjacent to the drying position of the receiver medium. Air flow from the air bearing structure outlet forms an air bearing for the receiver medium. A microporous filter positioned at the outlet and being adapted to convert the air flow from the outlet to a diffuse flow, the microporous filter being formed of an inner layer of very fine screen for optimum air diffusion and an outer layer of courser woven screen to add rigidity and protection from scuffing.

A stent formed of polymeric material, useful for the expansion of a lumen and the delivery of one or more therapeutic agents in situ is disclosed. The stent may be multi-layered, and may change shape at a state transition temperature governed by the materials forming the layers. Methods of use and manufacture are also disclosed.

Absorbable polyester fibers, braids, and surgical meshes with prolonged strength retention have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available, and could offer additional benefits such as anti-adhesion properties, reduced risks of infection or other post-operative problems resulting from absorption and eventual elimination of the device, and competitive cost. The devices may also be particularly suitable for use in pediatric populations where their absorption should not hinder growth, and provide in all patient populations wound healing with long-term mechanical stability. The devices may additionally be combined with autologous, allogenic and/or xenogenic tissues to provide implants with improved mechanical, biological and handling properties.

In the invention, a method is provided for producing a composite nonwoven fabric. A polymer is extruded into heated continuous filaments, possibly elastic, from the die head to a first chilled roller, wherein the extruder is configured to provide the continuous filaments to the chilled roller in a canted direction that is at a tangent or angle to the surface of the first chilled roller. The filaments are conveyed in a downward direction by way of chilled rollers to a nip. In a next step, the nonwoven web is sprayed with an adhesive and is laminated on the continuous filaments in the nip to form a composite nonwoven fabric. The continuous filaments move vertically downward approximately in line with the lamination process, facilitating automatic re-threading of filaments when they are broken or interrupted in their travel downward onto the chilled rolls.

A beaded preform includes a plurality of adjacently positioned beads for forming a plurality of voids in an engineered material. The beaded preforms may be comprised of a filaments (single strand of beads) and mats (two-dimensional and three dimensional arrays of beads). The filaments and mats may be coated to become tows and laminates, respectively, which may then be assembled into composite materials. The preforms may be produced using novel manufacturing apparatuses and methods, and incorporated into known manufacturing processes to produce porous structures, including stress-steering structures, in any material including metals, plastics, ceramics, textiles, papers, and biological materials, for example.

A peelable sealable co-extruded film, comprising: i. a skin layer capable of heat sealing against a rim of a container, to itself, or to another film and adapted to be peeled there from and comprising a hot melt adhesive resin; and ii. a core layer underlying said skin layer and comprising crystalline homopolymer polyethylene terephthalate; and a method for the preparation thereof.

Cellulose containing dope is extruded through orifices and into a stream of gas moving in a direction generally parallel to the direction that the filaments are formed with varying degrees of mechanical attenuation provided to the filaments using a take-up device, such as a winder.

A thermal bonding pattern for nonwoven fabric possessing improved abrasion resistance while retaining softness, comprising a basket-weave pattern or other pattern having a transition area (2) equal to at least 10% of bonding spot area (1) in FIG. 1, more preferably a transition area (2) equal to at least 50% of bonding spot area (1), and most preferably a transition area (2) equal to at least 100% of bonding spot area.

Absorbable polyester fibers, braids, and surgical meshes with improved handling properties have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available and have a decreased tendency to curl, in the preferred embodiment, due to the inclusion of relaxation and annealing steps following extrusion and orientation of the fiber. Filaments prepared according to these methods are characterized by the following physical properties: (i) elongation to break from about 17% to about 85% (ii) Young's modulus of less than 350,000 psi, (iii) knot to straight ratio (knot strength/tensile strength) of 55-80% or (iv) load at break from 1100 to 4200 grams.

A process and apparatus for making a shingle, together with the shingle made thereby, is provided, in which one or more thermoplastic materials are extruded or co-extruded to form an extrudate, with the extrudate being cut into a preliminary shingle shape, which is allowed to dissipate heat, and then is delivered to a compression mold, wherein the preliminary shingle shape is compression molded to substantially its final dimensions and is then discharged from the mold and allowed to cool.

The invention relates to a process for the production of a plastics article with a microstructured surface via production of a composite composed of a backing layer composed of a thermoplastic or thermoelastic with one or more structure layers, characterized in that the structure layer(s) is/are composed of from 1 to 100% by weight of a polymethacrylate moulding composition which comprises from 80 to 100% by weight of free-radical-polymerized methyl methacrylate units and from 0 to 20% by weight of other comonomers capable of free-radical polymerization, and which has an average (weight-average) molar mass Mw of from 30 000 g/mol to 70 000 g/mol and, where appropriate, is present in a. mixture with up to 99% by weight of a polymethacrylate moulding composition which is composed of from 80 to 100% by weight of free-radical-polymerized methyl methacrylate units and from 0 to 20% by weight of other comonomers capable of free-radical polymerization, and which has an average (weight-average) molar mass Mw of from 90 000 g/mol to 200 000 g/mol and the structure layer(s) obtain microstructuring via known structuring processes, after production of the composite. The invention further relates to the plastics articles themselves which are capable of production according to the invention, and also to their uses.

A robust process for the continuous preparation of solutions of high molecular weight UHMW PO that is capable of producing strong materials at high production capacity, is conservative of capital and energy requirements, and the articles made therefrom.