JP2009057678A - Process for making fiber-on-end materials - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for making fiber-on-end materials, wherein the materials can be used to make a variety of finished articles, and the process capable of making fiber-on-end materials of large planar dimensions, e.g., one meter wide or more, in an at least partly continuous or automated manner. <P>SOLUTION: A fiber-on-end material is prepared by skiving material of a desired thickness from a billet to produce comprising a plurality of fibers arranged parallel to and fused to each other, wherein at least one step in the preparation or skiving of the billet is carried out in a continuous manner, and wherein the skived material is optionally contacted with a solvent to dissolve a component of the fibers. An article contains the fiber-on-end material, a process for affinity separation uses a fiber-on-end capillary array, and an article comprises the capillary array. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

This application claims the benefit of US Provisional Application No. 60/83389, filed July 28, 2006, which is incorporated herein in its entirety for all purposes. To do.
The present invention is directed to fiber-on-end materials and articles made therefrom.

  Microporous membranes are prevalent in the chemical, food, pharmaceutical and medical industries, which separate impurities from the desired and unwanted components of the process stream, for example to remove impurities by filtration. Or used to separate and retain valuable or useful particulate species. Microporous membranes are also used for custom clothing such as outings that protect the wearer from elements such as wind and rain while providing breathability. They are also used in the processing of protective masks and clothing to help protect against toxic particulate species such as carcinogenic aerosols, spores and bacteria. In all of the above applications, performance is greatly limited by the largest pores in the membrane. Because the largest pores regulate the size of particles that can be excluded, the majority of the flow is driven to larger pores and the smaller pores will give the membrane a higher porosity number, This is because it hardly contributes to the flow rate. It is therefore desirable to be able to produce a porous membrane with little or no change in pore size.

  Uniform holes in a planar film can be created by many different processing techniques. For example, uniform capillary pores can be created by ion bombardment and track etching. They can also be created by using laser ablation, ion beam etching or photolithography. However, all these microfabrication methods are limited by one or more of a variety of factors such as cost, a limited number of suitable material substrates, the ability to create large area films, and low porosity. The

  The membranes without the open holes are used to separate chemical species by allowing some to diffuse and others not to diffuse. Life itself is maintained by selective diffusion through cellular lipid membranes, and desalination is used worldwide to make fresh or drinking water from seawater or brackish water; as well as gas purification, kidney dialysis, And many other chemical separations are known as entropy driven methods. Many materials with high selectivity that can be used as membranes are not used because the membranes themselves are substantially inferior in physical properties that allow them to be used as large area membranes with commercial value.

  Membrane or sheet structures can also be created by a “fiber on end” (FOE) process, in which multicomponent fibers with microfeatures are gathered in a preferred direction and then integrated together or Sintering produces a defect-free structure. When this solid structure is cut or fragmented in a direction perpendicular to the direction of the fibers, films and sheets with fine features are created. We have found that fiber-on-end arrays have useful properties for membranes and capillary arrays. Although hand lay-up of such materials is possible, it is not practical for commercial manufacture.

  One way to create a fiber-on-end material is to place thermoplastic fibers that have been pre-cut to a certain length in the cavity of the press mold. When the mold is closed and heat and pressure are applied, the fiber walls soften and fuse together. The amount of pressure and heat applied will depend on the fiber composition and structure. If too much pressure is applied, the hollow fibers can collapse or the core of the sheath-core fibers can deform. If the pressure applied is insufficient, the fibers will only coalesce and leave voids and defects behind. It is desirable to apply sufficient pressure to allow the fibers near the center to be compressed and to avoid collapsing of the fibers near the outside. Heat is also applied from the outside and is transmitted through the fiber assembly to the center. Careful heating and sufficient rate of heat conduction can allow the outermost fiber core to avoid breaking down, deforming or melting and still allowing the fibers near the center to fuse. it can.

  Similar care is taken when making fiber-on-end materials using binders or solvents. Sufficient time is required to allow the binder or solvent to diffuse to the surface and, if appropriate, evaporate. When heat activated binders are used, the thermal conductivity may be rate limiting, so as to ensure that the center fiber is cured before the outer fiber ,Pay attention.

  It can be seen that the creation of fiber-on-end materials with large dimensions by this method is limited by thermal conductivity and requires careful control and selection of time and heat.

  In European Patent Application Nos. 195860 A1 and 167094 A1, parallel fibers are united into a solid by wrapping the fibers on a drum and then combining or thermally fusing them, after which they are converted into parallel fibers. Skiving is performed in a direction perpendicular to the direction. The fibers arranged concentrically on the surface of the winding drum must be sliced radially with respect to the winding direction of the fibers. This cuts the integrated fiber layer, presses it to flatten it, cuts out a section of the flattened layer, reorients that section 90 degrees, fuses the sections together into a block, Can be achieved by cutting again into a trapezoid, placing the trapezoid along the periphery of the support drum, skiving the layers perpendicular to the fiber axis, and forming a membrane. In European Patent No. 0167694, a solid cylinder of sea polymer was made at a temperature above the melting point of the sea polymer, then cut axially into four segments that were flattened by pressing it flat. Cut into thin segments. By pressing and flattening this thick fused polymer block reinforced with a small polymer core, high tensile stresses are applied to those cores with a smaller curvature inside the quadrant and to a larger curvature outside. High compressive stress is applied to the near core. This adds high strain to the core and gives a non-uniform capillary structure. EP 195860 A1 and EP 167094 A1 require many steps to handle and are not readily adaptable to large, continuous or automated operations. Also, how quickly each fusion step can be accomplished using thermoplastics or reactive binders is the rate of heat conduction. These features limit the productivity of these methods and the practical membrane size.

  Accordingly, there remains a need for a method that can produce large dimension planar fiber-on-end materials, such as one meter or more wide, in at least a one-part continuous or automated manner. Exists.

  One aspect of the present invention is a fiber-on-fabrication produced by skiving material of a desired thickness from a billet comprising a plurality of fibers arranged in parallel and fused together. end) material, wherein at least one step in manufacturing or billet skiving is performed in a continuous manner, and the skived material is optionally contacted with a solvent to dissolve the fiber components. Material.

  Articles comprising such fiber-on-end materials are also provided.

  As used herein, the term “fiber on end” (FOE) refers to an array of fibers in which substantially all fibers are parallel to a common axis and perpendicular to any processing means. Say. In one embodiment of the invention, a plurality of fibers are arranged in parallel to each other and formed into a fabric or ribbon that maintains parallel fiber orientation. The fabric or ribbon is pleated and fused to form a solid material block or “billet”. As used herein, the term “billet” refers to a semi-finished solid material containing fused fibers. The fibers can be bonded together by thermal fusion of the fibers, by covering the fibers with a binder, or by solvent bonding. As used herein, the term “fiber” means any material having an elongated, elongated structure, such as a polymer or natural fiber. A fiber is generally characterized by having a length at least 100 times its diameter or width. As used herein, the term “filament” means an indefinite or extreme length of fiber as found naturally in silk. As used herein, the term “yarn” refers to a material in a form suitable for textile fibers, filaments, or other entanglements to form a knitted, woven, or textile fabric. A general term for continuous yarns.

  The fused solid formed from “fiber on end” generally does not necessarily need to be perpendicular to the fiber orientation, but is further processed by removing a thin layer using a sharp blade to form a membrane. Form. This process is known as “skiving”. As used herein, the term “membrane” is a discrete thin structure that can moderate the movement of species in contact with it, such as gases, vapors, aerosols, liquids and / or particulates. Thicker sections may be desired to reproduce the thickness of thin films and their unique end use, and even thicker ones, for example, to reproduce leather or slit leather applications; For example, such an article may be desired for cutting into tablets that can contain substances such as pharmaceuticals. A porous membrane can be formed by using hollow fibers or by using multicomponent fibers and dissolving and removing the components after the membrane has been skived from the billet. As used herein, the term “multicomponent fiber” means a fiber that contains two or more components (two components, three components, etc.). The term “porous membrane” as used in the present invention means a membrane containing openings (pores) that can be moved across the membrane, but not completely. The term “capillary array” as used in the present invention means, in the present invention, a membrane or sheet in which the holes can be partially or completely filled with other species.

  The process herein can be carried out continuously or partly continuously. One example of a continuous process is shown schematically in FIG. 1, which allows the continuous production of large area membranes without the heat conduction limitations of the prior art process. Various methods of billet manufacture are described below. If desired, billets can be made and then stored for subsequent skiving.

  Membrane and capillary arrays can be manufactured by skiving layers from fused blocks and optionally dissolving one or more fiber components. The skiving direction is generally essentially perpendicular to the fiber axis, but in certain applications it may be required to cut at an angle to the capillary axis.

Fiber Suitable fibers for use in embodiments of the present invention can be made by any of a variety of methods known in the art. Depending on the particular polymer (s) used, the fibers can be spun from solution (eg, polyurea, polyurethane) or melt (eg, polyolefin, polyamide, polyester). Materials, equipment, principles and methods for fiber production are discussed in detail in Fourne, F., Synthetic Fibers, (Carl Hanser Verlag, 1999) (translated and published by HHA Hergeth and R. Mears). .

Hollow fibers are well known and their manufacture and application are described, for example, in Fourne, p. 549 and Irving Moch, Jr., in “Hollow Fiber Membranes,” Kirk-Osmer Encyclopedia of Chemical Technology, 4 ^th edition, Volume. 13, p.312-337 (John Wiley & Sons, 1996).

  Bicomponent fibers and multicomponent fibers (eg, “sea-island” and “core-sheath” fibers) are discussed, for example, in Fourne, p. 539-548 and p. 717-720. As used herein, the term “islands in the sea” refers to one type of bicomponent fiber or multicomponent fiber (also described as multi-interface or filament-in-matrix). . An “island” is a finite length core or fibril of one or more polymers embedded in an “sea” (or matrix) of another polymer. The matrix is often dissolved away leaving very low denier filaments per filament. Conversely, the islands can be dissolved away leaving the hollow fibers. As used herein, the term “core-sheath” means a bicomponent or multicomponent fiber of two polymer types or two or more variants of the same polymer system. In a bicomponent core-sheath fiber, one polymer forms the core and the other polymer surrounds it as a sheath. Multicomponent core-sheath type fibers or two or more polymers can also be made containing a core, one or more inner sheaths, and an outer sheath. If the core is made as a cavity, there can be more than one cavity and more than one sheath can surround the cavity. The cavity can also have various shapes.

  Many polymeric materials can be used to create a fiber-on-end membrane by the methods described herein. The appropriate choice of polymer material will depend on several factors. One factor is the integration process and conditions that bind the fibers into a defect-free FOE billet. If high pressures and high temperatures are to be used to sinter adjacent fibers in the FOE bundle, the outer sheath or the polymer that constitutes the sea of the multicomponent fiber is the inner sheath of the fibers, It preferably has a melting point or softening point lower than the melting point of the polymer constituting the core or island. It may also be desirable that the glass transition temperature, softening point or heat deflection temperature of the inner sheath, core or island be higher than the melting point or softening point of the outer sheath polymer or sea polymer.

  If one of the polymer components is to be later dissolved and removed to create pores, such component should be readily soluble in the solvent. It is also desirable that the other polymer component or phase in the fiber be resistant or insoluble in the solvent used to dissolve the soluble polymer component. Examples of soluble polymers and solvents in which they are soluble include, but are not limited to, polyamides in formic acid, polyesters in strong alkaline solvents, polyurethanes in polar solvents such as dimethylacetamide, and toluene. Mention may be made of polystyrene and its copolymers in aromatic solvents and non-polar solvents such as dichloromethane, as well as polyvinyl alcohol in water and some polyethers and polyether copolymers. One skilled in the art knows that some polymers are not soluble in pure solvents but are soluble in mixed solvents. Such polymers can also be used as a soluble component in multicomponent fibers used to create membranes made by the processes described herein.

  When selecting polymer components, mechanical properties must also be considered. The fibers are required to have sufficient mechanical flexibility to withstand folding during the pleating process. When the fibers are fused to form a billet, the material must be susceptible to skiving by skiving operations known to those skilled in the art once or several times.

  The selection of the polymer component comprising the fiber will be determined in part by the end use of the FOE material created from the fiber. For example, if the fiber-on-end membrane produced by the process described herein is used in the manufacture of chemical and biological protective clothing, the polymer component of the fiber is a toxic chemical. It should be inherently resistant and impervious to drugs and biological agents. If the membrane is to be used for filtration or purification of a process stream in the chemical, biochemical or pharmaceutical industry, the polymer component of the fiber may be resistant to different species present in the process stream. desirable. If the fiber-on-end membrane is to be used to create one or more layers that are hydrophobic but breathable in firefighters' outfits, the inherently hydrophobic nature and fire resistance It is desirable to select a polymer component that has the properties of sexuality. It is anticipated that there will be several other applications for FOE membranes produced by the processes described herein. Thus, the polymer component of the precursor multicomponent fiber can be selected to provide the desired properties required for a particular application.

One skilled in the art will know that multicomponent fibers can be spun from a wide range of polymeric materials. Examples of suitable polymer material classes include, but are not limited to, polyolefins, polyesters, polyamides, polyurethanes, polyethers, polysulfones, vinyl polymers, polystyrene, polysilanes and polysulfides and fluorinated polymer homopolymers, copolymers and blends thereof. . The copolymer within or between each class of the polymer can be a random copolymer or a block copolymer. Specific examples of polyolefins include, but are not limited to, ethylene and propylene stereoregularity and random homopolymers; and their butenes, isobutylene, octene, tetrafluoroethylene, hexafluoropropylene, tetrafluoroethylene, methacrylic acid, acrylic acid , Vinyl acetate, vinyl alcohol, and copolymers with vinyl chloride, methyl acrylate, ethyl acrylate, butyl acrylate, or maleic anhydride. For example, the DuPont ^TM Surlyn ^(R) ionomer resin (EIduPont de Nemours & Company, Inc. , Wilmington, Delaware, USA) ionomer is derived from a polyolefin copolymer such as it is also be used as a component in the multicomponent fiber Can do. Specific examples of fluorinated polymers include, but are not limited to, homopolymers and copolymers of vinyl fluoride, vinylidene fluoride, terafluoroethylene, perfluoropropyl vinyl ether and hexafluoropropylene. Specific examples of polyamides (PA) include, but are not limited to PA-6, PA-66, PA-610, PA-611, PA-612 and PA-1212, and their N-alkyl analogs. Polyamides obtained from aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and polyamides obtained from aromatic diamines such as meta-xylene diamine and para-xylene diamine can also be used to form multicomponent fibers. Specific examples of styrenic polymers include, but are not limited to, polystyrene, styrene and copolymers of 1,2-butadiene and 1,4-butadiene, isoprene and isobutylene. These copolymers can be fully saturated, partially saturated or unsaturated. Partial or complete saturation is achieved by reduction of double bonds in the polymer. Further examples include ionomers (eg, from acids) and ionomer salts of styrenic materials.

  Useful thermoplastic polyurethane elastomers that can then be used to make the membranes include those made from polymeric glycols, diisocyanates, and at least one diol or diamine chain extender. Diol chain extenders are preferred. This is because the polyurethane made using it has a lower melting point than if a diamine chain extender was used. Polymeric glycols useful for the production of polyurethane elastomers include polyether glycols, polyester glycols, polycarbonate glycols, and copolymers thereof. Examples of such glycols include poly (ethylene ether) glycol, poly (triethylene ether) glycol, poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyl-tetramethylene ether) glycol, poly (Ethylene-co-1,4-butylene adipate) glycol, poly (ethylene-co-1,2-propylene adipate) glycol, poly (hexamethylene-co-2,2-dimethyl-1,3-propylene adipate), Poly (3-methyl-1,5-pentylene adipate) glycol, poly (3-methyl-1,5-pentylene nonanoate) glycol, poly (2,2-dimethyl-1,3-propylene dodecanoate) Glycol, poly (pentane-1,5-carbonate) glycol Lumpur, and poly (hexane-1,6-carbonate) glycol. Useful diisocyanates include 1-isocyanato-4-[(4-isocyanatophenyl) methyl] benzene, 1-isocyanato-2-[(4-isocyanatophenyl) methyl] benzene, isophorone diisocyanate, 1,6-hexane. Diisocyanate, 2,2-bis (4-isocyanatophenyl) propane, 1,4-bis (p-isocyanato-α, α-dimethylbenzyl) benzene, 1,1′-methylenebis (4-isocyanatocyclohexane ), And 2,4-tolylene diisocyanate. Useful diol chain extenders include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propylenediol, diethylene glycol, and mixtures thereof. Preferred polymer glycols are poly (triethylene ether) glycol, poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyl-tetramethylene ether) glycol, poly (ethylene-co-1,4-butylene). Adipate) glycol, and poly (2,2-dimethyl-1,3-propylene dodecanoate) glycol. A preferred diisocyanate is 1-isocyanato-4-[(4-isocyanatophenyl) methyl] benzene. Preferred diol chain extenders are 1,3-propanediol and 1,4-butanediol. A monofunctional chain terminator such as 1-butanol can be added to control the molecular weight of the polymer.

  Useful thermoplastic polyester elastomers are prepared by the reaction of a polyether glycol having a low molecular weight diol, for example less than about 250, with a dicarboxylic acid or diester thereof, such as terephthalic acid or dimethyl terephthalate. Examples include polyether polyester. Useful polyether glycols include poly (ethylene ether) glycol, poly (triethylene ether) glycol, poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyl-tetramethylene ether) glycol [tetrahydrofuran and Derived from copolymerization with 3-methyltetrahydrofuran], and poly (ethylene-co-tetramethylene ether) glycol. Useful low molecular weight diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propylenediol, and mixtures thereof. 1,3-propanediol and 1,4-butanediol are preferred. Useful dicarboxylic acids include terephthalic acid, optionally containing a small amount (eg, less than 20 mol%) of isophthalic acid, and diesters thereof.

  Useful thermoplastic polyesteramide elastomers that can be used to form fibers and membranes include those described in US Pat. No. 3,468,975. For example, such elastomers include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,5-pentane. Diol, 1,6-hexanediol, 1,10-decanediol, 1,4-di (methylol) cyclohexane, diethylene glycol or triethylene glycol, malonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid , Using polyester segments obtained by reaction with 3-methyladipic acid, 3,4-dimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or dodecanedioic acid, or esters thereof be able to. Examples of polyamide segments in such polyester amides are those produced by the reaction of hexamethylenediamine or dodecamethylenediamine with terephthalic acid, oxalic acid, adipic acid or sebacic acid, or ring-opening polymerization of caprolactam. Can be mentioned.

  Thermoplastic polyetheresteramide elastomers, such as those described in US Pat. No. 4,230,838, can also be used to make fibers and membranes. Such elastomers include, for example, low molecular weight (eg, about 300 to about 15,000) polycaprolactam, polyoenantholactam, polydodecanolactam, polyundecanolactam, poly (11-aminoundecanoic acid). , Poly (12-aminododecanoic acid), poly (hexamethylene adipate), poly (hexamethylene azelate), poly (hexamethylene sebacate), poly (hexamethylene undecanoate), poly (hexamethylene dodecanoate) By producing dicarboxylic acid-terminated polyamide prepolymers from poly (nonamethylene adipate), etc., and succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, terephthalic acid, dodecanedioic acid, etc. Can be manufactured. The prepolymer is then a hydroxy-terminated polyether such as poly (triethylene ether) glycol, poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyltetramethylene ether) glycol, poly (propylene ether) glycol , Poly (ethylene ether) glycol and the like.

An important challenge in the fiber alignment and bonding FOE process is that as-spun yarns are aligned side by side with high packing density, the fibers are oriented in the preferred direction, and then skived to form a film. Is to integrate them into a block that can produce This integrated block can take many forms depending on the desired end product. For example, a cuboid billet with fibers oriented perpendicular to the surface to be skived would produce individual sheet films when skived linearly. Similarly, a cylindrical billet with fibers oriented radially relative to the axis of the cylinder will produce a long continuous film when skived rotationally.

  Proper fiber placement will help to produce defect-free FOE membranes. Preferably, the fibers are arranged parallel to each other in a direction called fiber direction or fiber axis, with little or no crossing or overlap. Fibers that are not arranged parallel to the axis may cause structural defects when the fibers are integrated and then skived. There are several ways to arrange the fibers; the usefulness of each depends on the orientation method, the integration method, the form of the final billet to be produced, and which method is the most cost effective. In general, as-spun yarn is first wound on a bobbin. Most (but not all) alignment methods use these bobbins as feedstock. Examples of alignment methods include, but are not limited to, methods of forming fibers into ribbons, methods of weaving yarns into unidirectional fabrics, methods of skein winding, and methods on the bobbin itself.

  Impurities on the fiber surface may prevent the fibers, that is, the sheaths, from being merged into a close block. Without this good adhesion, films cut from blocks may have too low a tear strength and fail to function properly in their end use environment. The water applied to the fibers at the spinning stage facilitates the handling of the fibers and provides a clean surface.

Ribbon As used herein, the term “ribbon” refers to an array of thin flat fibers that are several inches to several feet wide, but can generally be only a few fibers thick. . The thickness of the ribbon is desirably less than 0.2 inch (0.51 cm), preferably less than 0.1 inch (0.25 cm), and more preferably less than 0.05 inch (0.13 cm). The fibers are lightly tied together so that the ribbon can be handled without the individual fibers breaking up. A common textile process for creating a ribbon of material is to take yarn bobbins and assemble them using hundreds or thousands of bobbins to creel, so-called beaming. The ends of each of these bobbins are combined into a comb and then rolled up on a mandrel to form a beam. Once the beam is formed, the individual fibers that make up the beam can be joined or bonded together by one or more of several different means, creating a sheet-like structure. .

  The appropriate yarn density of the beam is defined by the number of yarn ends per unit width of the beam, but depends on several factors such as the number of fiber ends in a single yarn end and the filament denier Will do. For example, if the filament denier, including the yarn end face, is small, multiple yarn ends may be required to create a beam where some or all of the fibers are joined to adjacent filaments. Conversely, if the fiber denier is large, fewer yarn ends would be required to create a partially bonded fiber beam. An optimum yarn end density is desirable. A sparse yarn end density can create a poorly bonded beam, and a very high yarn end density will result in a stiff beam when bonded. Those skilled in the art will realize that in order to create a bonded fiber beam, the product of the total number of yarn ends and the diameter of the yarn ends should be greater than the beam width.

  The fibers can be bonded together by any of a variety of techniques, including heating and fusing the fibers, coating the fibers with a binder, and bonding with a solvent, It is not limited to these. There are many ways to heat and fuse the fibers. For example, the beam containing the fibers can be passed through or over a heating unit (radiant heater, hot air convection heater, microwave heater, etc.), thereby allowing the fibers to join together. Also, the fibers in the beam can be joined by passing the beam through one or more calendar rolls, driven or non-driven. The beam can also control the fiber beam thickness through heated or unheated nip rolls. The heating method used depends on the type of fiber to be fused and the beam density, as is known in the art. It is desirable to join the fibers in the beam only to an optimum degree. If the fibers are weakly bonded to each other, they will break away from the beam and break. Broken fibers or loose ends can cause defects in the final fiber-on-end product. Ribbons can be formed from one type of fiber or from two or more types of fibers. Fiber types can be identified in many different ways. For example, the fibers can vary in cross-sectional size or shape, core size, shape or number per fiber, polymer component comprising the fiber. Fibers can also vary in properties such as color, chemical composition, surface chemistry and electrical conductivity. Different types of fibers can be distributed randomly during the beaming operation, or they can be assigned to a desired repeating or non-repeating pattern.

Another way to arrange the fabric yarns is to weave them into a unidirectional fabric. As used herein, the term “fabric” means a planar textile structure made by entanglement of yarn fibers or filaments. A “unidirectional fabric” is a fabric made of a woven pattern designed in only one direction for directional strength. The yarn can be woven in either the weft direction or the warp direction. Each has different advantages. Weaving the yarn in the warp direction requires less equipment and can adjust the yarn density because the yarn can be fed from a single bobbin. Instead, using yarns in the weft direction (for “single weft” fabrics) requires a large number of bobbins as in the case of the beaming operation, but the advantage is that once the creel is prepared, the fabric Can be produced at high speed. In both cases, the cross-axis yarn is a coarsely woven low melting point bonding fiber that ties the fabric together. In one embodiment of the process described herein, a unidirectional weft (“uni-weft”) fabric has a high fiber density in the weft direction but very coarse warp fibers. Woven and warp fibers are low melting fibers, which are melted after the weaving process and are used thereby to hold the weft fibers together.

  Similar to ribbons, woven fabrics can include one or more types of fibers. Different types of fibers can be randomly woven into the fabric or can be woven to create a specific repeating or non-repeating pattern.

Bobbin winding General winding has a helical angle for winding, and the yarns cross-wrap each other at that angle. However, it is also possible to wind the yarn at a very small angle so that the fibers are essentially parallel to each other. The fiber can be wound up to a thickness of 1 inch or more. However, for subsequent processing, 1/16 "to 1/4" (1.6 mm to 6.4 mm) is advantageous. These fibers can be bonded together by thermal fusion of the fibers, coating of the fibers with a binder, or solvent bonding. In the case of heat fusion, the bobbin can be placed in an oven where the fibers are roughly fused together. The oven temperature will depend on the fiber composition. The fused fiber material is then cut from the bobbin and placed flat to form a one-way mat of fibers. In our testing, we generally wound the fiber on a 6 ″ (15 cm) core to a thickness of 1/16 ″ (1.6 mm) to 1/8 ″ (3.2 mm). The bobbins were heated in an oven for 2 hours at 80-90 ° C. After being cut from the core, the fiber mats were joined together well at high fiber density, since they were thin enough and easily flattened And subsequently cut into shapes called conpons or pre-pregs.

  As an example, the fibers were wound on bobbins to a thickness in the range of 1/32 "(0.8 mm) to 1/8" (3.2 mm). The temperature used to fuse the fibers on the bobbin is determined according to the melting point of the outer sheath of the fibers. The fusion temperature is desirably about 15 ° C. above or below the onset of melting of the polymer comprising the outer sheath. The onset of polymer melting can be determined using a differential scanning calorimeter. If the polymer does not have a melting point, the fusing temperature can be in the range of the softening temperature of the polymer. Once the wound filaments are partially fused by heat treatment, the partially sintered fiber structure can be shredded or cut in a direction parallel to the bobbin axis, A curved or flat plate is obtained that contains fibers running in one preferred direction.

The skein winding fiber can be wound on a skein winder to create a gentle coil of yarn. This yarn can then be placed directly in the mold as a bundle of parallel fibers and integrated under heat and pressure to form a billet. Alternatively, the fibers can be bonded together by coating the fibers with a binder or by solvent bonding. Procedures and equipment common to the composites industry can be used to achieve the desired structure in this process and cut out the cut pieces or prepregs.

Billet formation and skiving The final billet requirements are determined by the desired product and processing costs. In the case of billets skived into separate sheets (linear skiving), all the fibers are arranged parallel to each other and are usually oriented perpendicular to the skiving surface. In some applications, skiving at an angle to the fiber axis provides additional value to the membrane. This type of skiving produces a sheet having the surface area to be skived. Billets suitable for linear skiving can be manufactured in a variety of ways, including but not limited to fusion after pleating and fusion after stacking. A schematic diagram of the process is shown in FIG. A ribbon or fabric 1 formed from a plurality of parallel bonded fibers passes through a pleating zone 2 and enters a fusing zone 3 where the pleats are fused into a solid block 4. The fiber-on-end membrane 5 can be continuously skived from the block (using the skiving knife 6) because the block is integrated, or the block can be collected later, eg Machine into parts for rotary skiving as described in.

The pleated fused ribbon or fabric can be run through a continuous pleating operation, where the ribbon or fabric is repeatedly folded and then stacked together. This process is similar to the pleating process used to make folded filter media or to pleat fabrics. This process is illustrated in FIG. Typical conditions are used in Example 1 below where a single weft fabric is pleated at a pleat height of 0.5 "(1.3 cm) and a pleated unit of 30 pleats per minute. The speed was run at 80 ° C. and 30 psi (0.21 MPa).

  Under heat and pressure, these pleats can be fabricated to join together to form a batt, in which the fibers are typically substantially perpendicular to the bat surface. Oriented. This bat can be used in several ways. The bat can be placed in a cuboid mold and then integrated under heat and pressure to form a cuboid billet, which can be skived into a sheet. In addition, the bat or cuboid billet formed therefrom is fragmented into segments (eg, trapezoids or other shapes), which segments are prepared for rotational skiving, as described below, to provide fibers. It can be assembled to be oriented radially.

  The pleating process further reduces the problems of heat transfer and solvent diffusion and minimizes the number of layers that must be skived from the solid material, thereby increasing productivity (eg, FIG. 2). Reference) can be adapted. If a thick membrane is desired, for example, in the production of capillary arrays, the membrane can be made to a nearly final shape by adjusting the folding depth to the desired thickness.

In the stacked bobbin winding process, the resulting fused fiber mats can be stacked together and then shaped to create a three-dimensional billet. This billet can be skived to form individual sheet-like films, or the billet can be cut into sections and the sections can be assembled into a cylindrical billet for rotary skiving. . The mat can also be cut into sections that can be assembled to orient the fibers in a radial direction. For example, the trapezoidal section 7 is cut from the mat (FIG. 3A) and then stacked together into a hexagonal shaped molding (FIG. 3B). When molded under sufficient heat and pressure, the individual sections will fuse together to form a skivable solid billet. Alternatively, several such solid billets can be stacked and fused together to form a single large billet suitable for wide film skiving. This process allows other materials to be added during the molding operation. For example, high-strength material or fibers between the segments are added in one or both directions completely across the billet and / or around the billet from the outside to the inside of the billet thickness (8 in FIGS. 3B, 3C). That can achieve a higher strength skiving film in one or both directions than can be achieved by the fiber on end itself.

Manufacture of Cylindrical Billets for Rotary Skiving Any of the above methods can be used to make a cuboid billet of FOE material. While these billets can be used for linear skiving to make individual sheet films, continuous roll films have preferred applications. A continuous roll can be produced by rotary skiving, in which case a cylindrical billet rotates about its axis, and by skiving the width is the width of the billet but a very long length. The film is manufactured (FIG. 6). In such a cylindrical billet, the fibers are essentially oriented radially from the axis. The inventors have developed a process for assembling a rectangular billet section into a cylindrical form suitable for rotary skiving.

  First, the billet is cut or machined into sections. In one embodiment, the section is a trapezoidal section as shown in FIG. 4A. As used herein, the term “trapezoidal section” indicates that the shape cut from the billet is trapezoidal in cross section. In another embodiment, the section is an annular sector. As used herein, the term “annular sector” suggests that the shape cut from the billet is an annular sector in cross section, as shown in FIG. The trapezoidal section is cut so that the fibers are oriented perpendicular to the base of the trapezoid (FIG. 4A). Trapezoidal sections are used to make billets that are two polygons with concentric cross sections. In a preferred embodiment, the three trapezoids are welded together to form a triple (FIG. 5A), and then the two triples are welded together to form a solid that is two hexagons with concentric sections. (FIG. 5B). This hexagon is mounted on a skiving spindle (FIG. 9) to create a cylindrical outer surface and to allow rapid skiving of a continuous FOE membrane. Similarly, a large number of trapezoidal sections can be cut and fused in this way, for example, eight sections can be cut to form two quadruples, and the two quadruples can be joined together. Billets can be made by welding to form a solid that is two octagons in cross section. Alternatively, an annular sector may be cut out and the fibers oriented vertically with respect to the outer arc (FIG. 11) in the same manner (FIG. 11) to form a cylindrical billet with two concentric cross sections.

  There are many ways to weld cut sections together. Sections can be welded by heating in an oven with or without pressure. Most other known plastic welding techniques can also be used, including but not limited to hot plate welding, vibration welding, and ultrasonic welding.

  Sometimes it is desirable to cover the machined surface before welding. Heat sealing the solid film 9 onto its surface (FIG. 4B) protects the fibers during the welding process and prevents the core from moving.

  The annular sector shown in FIG. 11 consists of essentially parallel fibers with the longest fibers essentially oriented radially. These sections (fans) are stamped from the sheet of fused filaments fused on the yarn bobbins in the oven and then laid flat as described above. They can also be die cut on the bobbin, leaving a slight curvature in the section. This curved section can be flattened as needed when all sections are fused under pressure and heated to produce the final billet. As shown in FIG. 10, the capping film on these segments varies in composition, molecular weight, and / or melting point depending on the value added to either billet processing, skiving, or product selection.

  The process described herein can be a porous membrane or capillary array of any desired width and length from on-end aligned fibers using a continuous and / or automated process. To make it practical. Furthermore, lower manufacturing costs can be achieved as a result of continuous process processing and reduced processing steps.

  Where numerical ranges are recited in this specification, unless stated otherwise, ranges are intended to include both ends and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range.

Applications Further processing steps and final applications will depend somewhat on the nature of the initial fiber and the thickness of the skived layer. If the fibers used to make the fiber-on-end material have specific properties, the membrane or capillary formed by skiving the material also has specific properties and unique values Will. Such properties include, for example, a specific distribution of pore sizes to form a unique array or different multicomponent fiber geometries; a unique or complex slope of the fiber axis; conductivity, surface energy Selected values of surface chemistry or optical index; color; or species diffusion (selective penetration). As used herein, the term “angularity” refers to the angle that the fiber axis in a given FOE material makes with a normal to the surface of that FOE material. For example, an article can include at least two parallel capillary arrays, where the capillaries in each array are essentially all deviated by a specific angle from the normal to the surface of the array ( That is, they are arranged (with the same slope), but the slope of the capillaries in one array is different from the slope of the capillaries in at least one other array.

Porous membranes and capillary arrays In one embodiment of the invention, the fiber-on-end material is a porous membrane or capillary array. If the initial fiber is hollow (ie, the core is air), using a properly manufactured billet, the layer or membrane skived from the fused block of fibers is porous and regularly spaced Will have uniform sized holes. If the first fiber is a bicomponent fiber with a solid core made from a material that can be melted after spinning, a porous membrane is made after skiving by melting the core to form pores be able to. Similarly, if each fiber has multiple cores of “sea-island” type and has a number of smaller dissolvable fiber cores arranged in different polymer seas, dissolve the islands. A film having smaller pores, that is, a microporous film can be formed.

  Many other variations are possible. For example, the initial fiber is a central core that is air or a solid that can be dissolved and removed, an inner sheath that is rigid and contributes to a specific function (eg, hydrophilicity, hydrophobicity, conductivity), and an inner sheath or core It can be a tricomponent fiber having an outer sheath that can be fused at a lower temperature than the material.

  As another example, the first fiber is a central core that is air or a solid that can be dissolved and removed, an inner sheath that can change volume in the presence of external stimuli (ie, temperature, chemical exposure, etc.) And a tricomponent fiber having an outer sheath that can be fused at a lower temperature than the inner sheath or core. Membranes made from such fibers can change the size of the pores, thus making it possible to change the permeability whenever an external stimulus is loaded or removed.

  As yet another example, a fiber-on where the capillary wall has active or reactive chemical substructures on its surface, such as carboxylic acid groups, hydroxyl groups, amine groups, epoxy groups, anhydride groups, etc. -End sheets or membranes can be made. Such a sheet or membrane comprises a dissolvable central core, an innermost sheath containing an active or reactive chemical substructure on the surface after the central core has been dissolved, and an innermost sheath or core. It can be made by processing FOE billets using multicomponent fibers that include an outermost sheath that can be fused at a lower temperature than the material. Alternatively, the fibers may be comprised of an inner sheath that is hollow and has the desired partial structure on the surface, and an outer sheath that can be fused at a lower temperature than the innermost sheath. Membranes made from such fibers can be used for species affinity separation. Because, as in membrane chromatography applications described in R. Ghosh, “Protein separation using membrane chromatography: opportunities and challenges”, Journal of Chromatography, 952 (1-2), pp. 13-27, 2002, This is because the seed flows through the capillaries of one or more FOE capillary arrays. As known to those skilled in the art of chromatography, particularly membrane chromatography, active or reactive chemical substructures along the walls of the capillary need to be purified or removed from the process stream. To add or graft other reactive groups, such as sulfonic acid groups, quaternary amine groups, metal ions, enzymes, proteins, etc., that will selectively bind to other species or chemical species Can be used for Those skilled in the art know that conventional membranes exhibit a wide distribution in pore size. Because of this variation in pore size, fluid flow is biased through the largest pores in the membrane, and small pores do not contribute significantly to the overall flow rate. For membrane chromatography applications, it is desirable that all pores with active sites contribute to the fluid flow and therefore contribute to the separation process.

  The uniform capillary pores achieved with the FOE capillary array described herein can allow a more uniform flow through all the pores in the membrane and enhance the efficiency of the separation process.

  Some applications can benefit from a bimodal, trimodal, or other controlled distribution of hole or core size, where one hole is functional and other holes are not. This can be achieved by using a mixture of fiber diameters or fiber component diameters. For example, hollow fibers having the same outer diameter but different wall thicknesses and thus different pore sizes can be used.

  Examples of FOE membrane applications described herein include, but are not limited to, a defined size distribution (eg, monodisperse, bimodal if two different diameter fibers are used). Filters for particle size measurement, chromatographic membranes, and adaptive membrane structures and apparel that change permeability in response to a stimulus, as described below.

  The porous membranes described herein are described in pending U.S. patent application Ser. Nos. 11/118961, 11/119484, 60/729110, and 60/729193. Can be used as a pore-containing component of a compatible barrier membrane structure, as described in US Pat. The compatible membrane structure includes first and second membranes having pores, and moving the first membrane such that the pores of the first membrane are substantially or completely in register with the pores of the second membrane. By reacting with a second membrane in a non-located position, thereby responding to an actuation stimulus that alters the permeability of the membrane structure. In an alternative compatible membrane structure, the porous membrane of the present invention is one of two adjacent membranes, and the second membrane includes an array of protruding elements, each protruding element being porous. Can be inserted into the pores of the porous membrane and is shaped and in position to enter the pores of the porous membrane when one or both membranes are moved towards each other in response to a stimulus load or removal. As each protruding element enters its corresponding hole, it contacts the inner surface of the hole in a manner that creates a seal between the protruding element and its corresponding hole, thereby penetrating, convection and / or diffusing. Eliminate the path.

  Examples of articles in which a compatible membrane structure can normally be incorporated include, but are not limited to, clothing (eg, protective clothing, protective covers, hats or other head covers, hoods, masks, gowns, coats, jackets, shirts) Enclosures (eg, tents, safety rooms, clean rooms, greenhouses, residential facilities, office buildings or storage containers); and gases, vapors, liquids and / or Or the valve | bulb for controlling the flow of microparticles | fine-particles is mentioned. Protective covers are protective clothing for chemical protection, biological protection, or both, including but not limited to coveralls, protective clothing, coats, outerwear, limited use protective clothing; gloves; socks, boots Shoes or boot covers, subons, hoods, hats or other head covers, masks, shirts, medical garments, surgical masks, medical or surgical gowns, or slippers.

  The pores of the membrane can also be chemically functionalized to give special properties such as, for example, catalytic or enzymatic activity, reactivity, adsorptivity, hydrophilicity, hydrophobicity and the like.

  The porous membranes described herein can also be used to support other inorganic, organic or biological materials either on its surface or inside the capillary pores. These materials can be physically supported on the membrane or chemically grafted. By introducing other substances onto or within the pores of the membrane, a composite membrane is formed that can be used for many different applications such as filtration, separation, purification, protection, detection and diagnosis. be able to.

  The porous membrane described herein can also be used as a template for the synthesis or fabrication of advanced materials. The capillaries can be sites that die cast or replicate the inverted image structure. The uniform capillary pores of the membrane can be used as a small reactor for synthesizing materials such as microtubes or nanotubes. These state-of-the-art materials can be left in the pores to obtain a composite membrane, or the membrane can be dissolved and removed in a suitable solvent and recovered. If the latest materials are stable at very high temperatures, they can be recovered by incinerating or burning the outer membrane at high temperatures.

In another embodiment of a membrane with filled holes or capillaries , the fiber-on-end material is a membrane or capillary array containing filled or partially filled holes or capillaries. For example, the core-sheath fiber core material used may be left undissolved if necessary, depending on the composition, the core material, such as fire resistance, antibacterial activity, thermochromic properties, etc. Add special functions to the membrane. For example, the core material can include a polymer mixed with sufficient levels of flame retardants, antibacterial agents, insecticides and insect repellents to impart such properties to articles including membranes. A few examples of flame retardants that can be incorporated in this way are halogen-containing and phosphorus-containing flame retardants, including but not limited to decabromodiphenyl oxide, cyclic phosphonates, triphenyl phosphate, poly (sulfonylphenylenephenyl) Phosphonates) and ammonium polyphosphates. Surface properties can also be improved by using a core material comprising an antistatic agent or an electrically conductive material, or a hydrophobic or hydrophilic material (eg, a polymer or oligomer).

  If the fiber-on-end material is skived to form a thick layer, longer capillaries can be made rather than shorter holes. Such capillary membranes can be used to selectively remove fluid by capillary action or to store and distribute fluid in a controlled manner. Such membranes can be used for controlled release of drugs, for example in medical materials, devices or implants, including but not limited to bandages, wound dressings, catheters, prostheses, pacemakers, heart valves , Artificial hearts, knee and hip joint implants, vascular grafts, orthopedic fasteners, ear canal shunts, cosmetic implants, implantable pumps, hernia patches, and artificial skin. The membrane itself can be made from materials that are absorbed by the body for extended periods of time when implanted.

  The capillary membrane can be impregnated with a variety of functional materials. As used herein, the term “functional material” refers to pouring it into the capillary of the membrane, such as, but not limited to, thermoregulation, antibacterial activity, fire resistance, optical properties, electrostatic properties, and It means a substance that gives desired properties such as corrosion resistance. The functional material may be the liquid itself that has been drawn into the pores by capillary action or dissolved in the solution, where the solvent is evaporated after impregnating the membrane with the solution. The functional material may also be spun as part or all of the fiber sheath or core component used to make the membrane.

  For example, paraffin wax is an example of a phase change material used in thermoregulation applications. Accordingly, the paraffin wax can be dissolved in methylene chloride and taken into the porous capillary membrane by suction through capillary action, and then the solvent can be evaporated to leave behind the paraffin wax. Articles containing such filled capillary membranes exhibit desirable thermoregulatory properties depending on the ambient temperature. Representative examples of articles containing capillary membranes incorporating phase change materials include, but are not limited to, blankets, household and automotive seat quilts, bedding (eg, pillows, pillow cases, sheets, comforters, Bedspreads, mattresses, mattress covers), waterproof and cold-resistant clothing for underwater diving, footwear (eg shoes, boots, ice skating boots, sneakers and slippers), insole and lining, gloves and mittens, hat, ski mask , Jackets, coats, hoodies, winter clothes, ski trousers and other subons, warm underwear and inch metric apparel, vests, shirts, blouses, sweaters, dresses, and potholders.

  Antibacterial and deodorant agents can also be incorporated as functional fillers in the fiber-on-end materials described herein. Antibacterial agents are bactericidal, antifungal (including fungal activity) and / or antiviral agents. These include, for example, chitosan and its derivatives, triclosan, cetylpyridinium chloride, polybiguanide compounds; and alkyls of 4-hydroxybenzoic acid (especially methyl, ethyl, propyl, in particular) called “parabens”. And butyl) esters and benzylesters. The use of a specific antibacterial or deodorant functional filler in a specific capillary membrane structure requires a solvent that dissolves the functional filler but does not affect the membrane structure. The antibacterial and deodorant articles of the present invention are applied to applications such as clothing, including but not limited to footwear articles (eg, boots, shoes, slippers, sneakers) linings and insoles, Includes gloves and mittens, hats, shirts and blouses, outerwear, sweaters, dresses, inch-meter apparel, and medical clothing; health care products including medical draperies, antibacterial tissues, handkerchiefs, and medical packaging.

  Insecticides and insect repellents can also be used as functional fillers. Examples include, but are not limited to, N, N-diethyl-m-toluamide (“DEET”), dihydronepetalactone and its derivatives, citronella oil, backhousia citriodora oil, lavender tea tree oil ( essential oils such as melaleuca ericafolia oil, callitru collumelasis (leaf) oil, callitrus glaucophyla oil and white tea tree oil (melaleuca linarifolia oil); and limited Pyrethroid insecticides such as permethrin, deltamethrin, cyfluthrin, alpha-cypermethrin, etofenprox and lambda-cyhalthrin Is mentioned. Articles containing insecticidal and / or insect-repellent substances or compounds obtained therefrom, or articles incorporating the filled capillary membrane structure of the present invention are applied in applications such as clothing, and include Not including hats, hoods, scarves, socks, shoe linings, shirts and blouses, shorts, subons; tents, turpaulins and bedding.

In a "sea-island" type, where the microprojection fibers have a single core or a number of smaller fiber cores ("islands") placed in different polymer seas, and do not dissolve the islands If the sea is soluble, the sea can be etched to form a surface with many microprojections or hairs. Such a surface can be made to have superhydrophobic properties, useful for example for self-cleaning surfaces or waterproof materials.

  All of the above examples are of higher value and utility than the fiber itself. FOE materials produced as described herein can be applied to new applications in filtration, protective membranes, pharmaceutical delivery, self-cleaning superhydrophobic surfaces and many other exciting new materials. it can.

Examples The following examples illustrate specific embodiments of the present invention. The embodiments of the invention on which these examples are based are for illustrative purposes only and are not intended to limit the scope of the appended claims.

  Abbreviations have the following meanings: “h” for hours, “min” for minutes, “m” for meters, “cm” for centimeters, “mm” for millimeters, “μm” Is micrometer, "g" is gram, "mL" is milliliter, "psi" is pound per square inch, "ksi" is 1,000 pound per square inch, "MPa" is megapascal And “rpm” means the number of revolutions per minute, respectively.

Surlyn ^(R) is a registered trademark of EI du Pont de Nemours and Company.
Elvamide ^(R) is a registered trademark of EI du Pont de Nemours and Company.
Nucrel ^(R) is a registered trademark of EI du Pont de Nemours and Company.

[Example 1]
This example describes a lab-scale fiber-on-end process that was used to create a microporous membrane.

Core-sheath fibers were spun on a continuous fiber spinning line. A schematic diagram of the spinning line is shown in FIG. The spinback used to create the core-sheath filament structure has been previously described in US Pat. No. 2,936,482 and subsequent patents and publications. Sheath of the fiber is formed from Surlyn ^(R) 8150 resin. This resin is an ethylene / methacrylic acid copolymer in which the methacrylic acid groups are partially neutralized with sodium ions and is commercially available from EI du Pont de Nemours and Company (Wilmington, Delaware, USA). . Core of the fiber is formed from Elvamide ^(R) 8061 nylon multipolymer resins. This resin is a general-purpose nylon multipolymer resin having a low melting point (T _m = 156 ° C.) and is also commercially available from EI du Pont de Nemours and Company.

Before spinning fibers, the Surlyn ^(R) 8150 resin and Elvamide ^(R) 8061 nylon multipolymer resins, while flowing a vacuum oven in a dry nitrogen gas, and then dried for 16 hours at 60 ° C.. The dried polymers (12 and 13) were melted in two separate co-rotating twin screw extruders (14 and 15). Extruder supplied molten ionomer is set to 255 ° C., molten Elvamide ^(R) 8061 extruder supplying nylon multipolymer resins was set to 200 ° C.. Both polymer melt streams from each extruder were fed to separate Zenith gear pumps, which then metered the molten polymer into the spin pack 16. Speed of the two gear pumps, as ionomer 11.2 g / min and Elvamide ^(R) 8061 nylon multipolymer resin is 4.8 g / min, and set in advance. These flow rates allowed the outer sheath of the core-sheath fiber to be nominally 70 wt% and the core nominally 30 wt%. The spin pack was heated to 244 ° C. using the heating block 17. Both polymer streams were filtered through three 200 mesh screens and one 325 mesh screen in separate partitions in the pack. After filtration, the copolyamide was metered through an orifice with a diameter of 0.015 "(0.38 mm) and a length of 0.030" (0.76 mm) into the surrounding ionomer sheath pool. This ionomer is 0.004 "(0.10 mm) measured from the flat metal surface including the core orifice and the top surface of its plateau, as described in U.S. Pat. No. 2,936,482. The sheath and core were then weighed to be placed concentrically at an offset. The counterbore was then 0.0625 "(1.6 mm) in diameter and about 0.325" (8.26 mm) in length. ) To reach a filament forming orifice with a diameter of 0.012 "(0.30 mm) and a length of 0.050" (1.3 mm). At the outlet of the spinneret orifice, a total of 34 individual cores- A sheath filament was created.

  These resulting 34 filaments were cooled with ambient air (quenching zone 18), surfaced with water (19), and then placed on a guide about 8 feet (2.4 meters) below the spin pack. Focused. The 34 filament yarn was pulled away from the spinneret orifice by a pair of rolls (20) rotating at about 1,200 meters / minute through the guide. From these rolls, the yarn was taken up by a conventional winder 21 and wound on several bobbins. The average denier per filament of this yarn was determined to be 3.6.

The core / sheath yarn was removed from the bobbin and wound on a rotating heated roll set at 85 ° C. The rotation speed of the roll was set to about 58 rpm. The outer diameter of the roll was estimated to be 10.11 ″ (25.68 mm). While the yarn was being wound by the rotating roll, the guide was swung along the direction parallel to the axis of the rotating cylinder. The rocking guide was made by Mossberg Industries (Cumberland, Rhode Island), and the amplitude of the guide was set to 5 inches (13 cm), so that the yarn was 5 on the heated roll. Spread over an inch (13 cm) distance, keeping the guide linear velocity small and ensuring that the winding helix angle is extremely small, about 2,800 meters of core-sheath yarn heated After the winding was completed, the rolls were allowed to cool to room temperature. This allowed each winding yarn to be lightly fused to the nearest yarn and 5 "(13 m) were able to form a ribbon of width. This lightly fused ribbon was cut and removed from the roll and placed flat on the table. The resulting ribbon was 31.75 "(80.64 mm) long, 5" (13 cm) wide, and about 0.03 "(0.76 mm) thick. The weight of the ribbon was 38.24 g. There were about 118,500 core-sheath filaments, all running parallel to the longest axis of the ribbon, and the density of the ribbon was estimated to be 0.49 g / cm ³ . The density was estimated to be 349 yarn ends per linear inch, producing a total of 4 ribbons in this manner, and each ribbon was divided into 2 equal parts using a sharp blade to give 8 ribbons. The length was 31.75 "(80.64 mm), the width was 2.5" (6.4 mm), and the thickness was 0.03 "(0.8 mm).

Each ribbon was then manually folded to a repeat length of 2.25 "(5.72 cm) to form a pleat. The pleating was done along the length of the ribbon, but it also constituted the ribbon The pleated ribbons were then compressed in a convection oven set at 85 ° C. under a load of 8.5 lb (3.9 kg) for 30 minutes. The pleated ribbon fibers were fused to some extent with each adjacent fiber, and each plate was marked to indicate the orientation of the fibers, resulting in a total of 8 somewhat fused plates. They were approximately 2.5 "x 2.25" x 0.45 "(6.4 cm x 5.72 cm x 1.14 cm). The eight plates thus fused to some extent were stacked on top of each other while confirming that the orientation of the fibers on all the plates was in the same direction. The entire stack was heated in a convection oven at 85 ° C. for 60 minutes. The heated plate stack was removed from the oven and immediately sandwiched between two preheated aluminum plates and then compressed between heated Carver hydraulic presses. The press temperature was set at 85 ° C. and the compression pressure was 15 psi (0.10 MPa). After compression for 30 minutes, the hydraulic press heater was turned off and the stack was allowed to cool to room temperature while still applying a compression pressure of 15 psi (0.10 MPa). By this process of compressing the pre-integrated stack of plates, they fuse together and have a density of 0.83 g / cm ³ and 2.5 "× 2.25" × 1.99 "(6.4 cm A single block with dimensions of 5.72 cm x 5.05 cm) was formed and this block was used with a band saw to give a final dimension of 1.98 "x 1.98" x 1.99 " × 5.03 cm × 5.05 cm).

The pre-integrated block was placed in the mold cavity such that the oriented fiber orientation of the block was perpendicular to the vertical wall of the mold cavity. The cavity of the mold was 2.0 "x 2.0" (5.08 cm x 5.08 cm) square and its height was 5 "(13 cm). Two metal rams were placed at the open end of the mold cavity, the mold was placed between Carver hydraulic presses, and a pressure of 1,000 psi (6.9 MPa) was applied to the ram. The outer wall of the mold was heated using a circular Watlow band heater wrapped around and closely mounted, the mold temperature was measured by a thermocouple inserted in the mold wall, and the mold temperature was controlled by temperature. Once the heater was switched on, it took 40 minutes for the thermocouple to stabilize at 95 ° C. The polymer block was held at this temperature and a pressure of 1,000 psi (6.9 MPa) for 2 hours, Then turn off the heater, still 1,000p The block was allowed to cool while applying a pressure of si (6.9 MPa). When the block cooled to room temperature, it was removed from the mold cavity. The final dimensions of the block were 2.0 "x 2.0 "x 1.64" (5.08 cm x 5.08 cm x 4.17 cm). The density of the block was estimated to be 0.98 g / cm ³ . This density suggests that the block is fully integrated and that there is little or no void in the block.

  As shown in FIG. 7, from a completely integrated block, the thickness was changed by skiving to obtain a thin film. The film was skived on a Bridgeport vertical milling machine that had been modified for this particular application. As the cutting tool (22), a wedge-type tungsten carbide blade, HB971 (manufactured by Delaware Diamond Knife) was used. The cutting plane was perpendicular to the orientation axis of the fibers used to produce the solid polymer block. The angle between the workpiece surface and the blade was fixed at 20 degrees. The cutting speed was 100 inches / minute (254 cm / minute). The blade was moved along the plane of the cutting surface in a direction of 45 degrees to the workpiece (see FIG. 7). This angle generated both sliced and tilled vectors. The dimensions of the skived film were 2.0 "x 1.64" (5.08 cm x 4.17 cm). Three different thickness samples were obtained: 0.002 "(51 [mu] m), 0.004" (102 [mu] m) and 0.006 "(152 [mu] m).

The skived film sample was immersed in a high concentration of formic acid (90 mass%) for 5-10 minutes. Formic acid is eluted Elvamide ^(R) 8061 nylon multipolymer resin phase of each film, thereby produced a microporous membrane. The weight of the film sample before and after dissolution of the Elvamide ^(R) 8061 nylon multipolymer resin phase was measured. Gravimetric analysis showed that Elvamide ^(R) 8061 nylon multipolymer resin phase is about 30 wt% of the film. The density of Elvamide ^(R) 8061 nylon multipolymer resin was 1.07 g / cm ³ . Therefore, the porosity of the film was estimated to be 28%. A sample of the membrane thus created was analyzed with a scanning electron microscope (SEM). SEM images showed cylindrical holes in the membrane. SEM images also showed that there were no pinholes or other defects in the film sample. Analysis of the SEM images (NIH 1.62 image analysis software developed by the National Institute of Health, Bethesda, MD) showed that the average pore size of the membrane was 9.8 μm. The microporous membrane of this example was also characterized using a flow-through capillary porometer (supplied by Porous Materials Inc. (Ithaca, NY)). The porometer results indicated that the mean flow pore diameter was 11.4 μm.

[Example 2]
This example describes the formation of a solid billet by pleating and integrating a unidirectional fabric.
Core having a core Surlyn ^(R) 8150 resin sheath and Elvamide ^(R) 8061 nylon multipolymer resins - the sheath fibers were spun as described in Example 1. This core-sheath fiber was woven to obtain a plain unidirectional fabric. The fabric count was 5 × 35.6, the width was 18 3/16 inches [46.2 cm], and the weight was 5.913 oz / yd ² . The fabric was cut along the fiber direction to form several fabric ribbons 2.5 "(6.4 cm) wide and approximately 18" (46 cm) long. Using the same method as described in Example 1, each ribbon was manually folded to a repeat length of 2.25 "(5.72 cm) to form pleats. Four such pleated ribbons were stacked on top of each other and compressed and bonded together under a load of 8.5 lbs at 90 ° C. for 30 minutes, resulting in a density of 0.42 g. / stacking cm ³ of pre-integral of .10 like to obtain a plate such pre integral plate together by applying a pressure of 60 psi (0.41 MPa) using a hydraulic press at a temperature of 90 ° C., The resulting block had a density of 0.95 g / cm ^3. The block was finished to approximately 2.0 "× 2.0" × 2.17 "(5. 1cm x 5.1cm x 5.51cm) in the mold (actual Examples as described in 1) at a pressure of 95 ° C. temperature and 1,000 psi (6.9 MPa), and further integrated. The resulting block had a density of 1.0 g / cm ³ and was fully integrated.
In Examples 1 and 2, the fiber ribbon and unidirectional fabric that were integrated to some extent were pleated by hand. Pleating and integration can also be performed continuously at much higher speeds using automated machines. In a commercial process, a pre-integrated fiber beam or unidirectional fabric is continuously fed to the heating zone where the sheet is heated at the desired temperature. The heated sheet can then be passed through a commercial rocking knife pleating machine, such as that manufactured by JCEM Gmbh (Switzerland). This machine will produce pleats of the desired amplitude on the sheet. The pleated sheet can then be sent to a heated stuffer box where each pleat is pressed against the preceding pleat with the desired force. The high temperature and pressure in the stuffer box allow them to be joined together to form a solid sheet structure, where the fibers run perpendicular to the plane of the sheet and the thickness of the sheet is that of the pleats. Equal to amplitude. The solid can then be cut into the desired shape, which can then be further integrated at high temperature and pressure to form an FOE billet for skiving.

Example 3
Pleating and integration of unidirectional fabric with an automatic pleating machine The unidirectional fabric described in Example 2 was fed into an automated rocking knife pleating machine. The pleating speed was set at 30 pleats / min and the pleat height was set at 0.5 "(1.27 cm). The resulting pleats were continuously applied to their nearest pleats on the same machine. The bonding temperature was 80 ° C. and the applied pressure was 30 psi. The resulting integrated structure was 18 ″ wide and 0.5 ″ thick.

Example 4
Production of a continuous membrane by rotary skiving of fused trapezoidal sections is shown in FIGS. 4, 5 and 6. The FOE block was made as described in Example 1. The blocks were machined into trapezoids using conventional machining techniques. The block was machined so that the fibers were oriented perpendicular to the trapezoidal parallel surface. The trapezoidal diagonal surface was machined to an angle of 60 degrees with respect to the parallel surface. The dimensions of each trapezoid block were 2 ″ (5 cm) at the longest side L (FIG. 4A) and 2 ″ (5 cm) in thickness. Six trapezoidal blocks are required for each complete assembly.

Each block had a capping film bonded to two diagonal surfaces. A method of applying the film is shown in FIG. 4B. Capping film 9, 0.005 "composed of Surlyn ^(R) resin film having a thickness of (127 [mu] m). The film for coupling to block, using a hydraulic press with heated lower platen. Lower platen 11 It is allowed to act .Kapton heated to 100 ° C. ^(R) polyimide film, a thickness 0.005 "(127 [mu] m), as the peeling layer 10 laid on the lower platen. Capping film 9 is placed on the Kapton ^(R) polyimide film, and at that temperature over about 5 seconds. The trapezoidal block was placed on the film so that one diagonal surface was in contact with the film. The block was pressed against the film with a force of 600 lb (2.7 kilonewtons) to obtain a bond pressure of 200 psi (1.4 MPa). This pressure was maintained for 60 seconds. This process was repeated for another diagonal surface and for the remaining 5 trapezoids.

  The individual trapezoids were then welded together using a Branson vibration welder, Model Kiefel 240G. The machine had an upper platen fixed in the vertical direction and oscillated in the horizontal direction. The lower platen moved vertically but was fixed horizontally. Welding the trapezoid into a cylindrical billet was done in two stages. First, three trapezoids were welded together to form a triple body (FIG. 5A). The two triplets were then welded together to form the final billet (FIG. 5B).

  To form the triple, the two trapezoids were placed in a specially designed fixture that was secured to the lower platen. This fixture clamped the two trapezoids firmly so that they could not move during the welding process. Each trapezoid was oriented with one diagonal surface horizontally and the other diagonal surface so that the third trapezoid could fit snugly between these two trapezoids (FIG. 5A).

Once the trapezoid is firmly clamped in the fixture, the lower platen is raised and placed in contact with the trapezoid, where it is pressed together with a force of 1,800 lb (8.0 kilonewtons) A bond pressure of 130 ^* psi (0.90 MPa) was produced. The upper platen vibrates for 10 ^* sec at an amplitude of 0.070 ″ (1.8 mm) at 60 Hz (FIG. 5A, vibration direction is up and down with respect to the page), so that the three trapezoids are welded together to form a triple body. The second trapezoid set was also welded together according to the same process.

  The triples were then welded together using the same vibration welder used for trapezoidal welding. Specially designed fixtures were attached to the upper and lower platens to hold the triple body firmly during welding. These fixtures held the triplets so that when the lower platen was raised, the oblique surfaces of each triplet were in contact with each other.

  Once the triples were properly positioned and fixed, the lower platen was raised to place the triples in contact with each other (FIG. 5B). They were pressed together with a force of 1,800 lb (8.0 kilonewtons), which resulted in a bond pressure of 257 psi (1.77 MPa). The upper triplet was vibrated at 60 Hz with an amplitude of 0.070 ″ (1.8 mm) for 13 seconds. The triple was now welded into a single billet 23 of six trapezoids, In the trapezoid, the fibers were mostly oriented in the radial direction.

  A 1.0 "(2.54 cm) diameter hole was drilled in the center of the billet. A specially machined spindle 24 was designed to drive the billet 23 without overloading the welded joint. The spindle was fitted into a 1.0 "diameter hole and the plate 25 was bolted to the billet to drive the billet (Fig. 9A). The spindle was mounted on a standard metalworking lathe. A skiving knife was mounted on the lathe turret. The knife had a tungsten carbide blade polished at an angle of 36 degrees. The knife was mounted with a clearance angle of 8 degrees (FIG. 9B). The billet was rotated at 17 rpm and the knife was moved at a feed of 0.002 ″ (51 μm) per revolution. This resulted in a final film thickness of 0.002 ″ (51 μm).

Example 5
This is an example of forming a membrane from hollow fibers having inner and outer sheaths. Here, the outer sheath was thermally fused to the matrix while the inner sheath maintained a hollow hole. This also indicates that the holes can have many cross-sectional shapes. Sheath outer fibers, Nucrel ^(R) 0411HS ethylene copolymer, DuPont made of thermoplastic ethylene-methacrylic acid copolymer; and the inner sheath is 3.14IV polycaprolactam, their ratios are 40/60 met It was. A micrograph of a cross section of the raw fiber is shown in FIG. 12A.

  The fiber was wound on a bobbin at 3,500 meters / minute as a 45 denier 10 fiber yarn. In a concentric core-sheath polymer configuration, the polymer was fed from a spinneret at 225 ° C. and passed through an orifice as shown in FIGS. 6A and 4B of US Pat. No. 5,439,626. These yarns are then removed from the bobbins, arranged essentially in parallel, placed in a rectangular groove, compressed by a rod placed in the groove at about 120 ° C. and 780 psi, then cooled and blocked I made it. The membrane was obtained by skiving at about 90 degrees with respect to the fiber axis. A photomicrograph is shown in FIG. 12B. The resulting membrane was a flexible membrane and had inelastic pores that maintained constant dimensions when the membrane was bent or stretched.

1 is a schematic diagram of one embodiment illustrating a process of pleating, fusing and skiving. 1 is a schematic diagram showing the production of a thin solid by adjusting the depth of a pleat. 1 is a schematic diagram showing the manufacture of billets by cutting, stacking, and forming trapezoidal shapes from an integrated mat. 1 is a schematic diagram showing application of capping film to a trapezoidal section. Fig. 4 is a schematic diagram showing the integration of three triplets into a triple (5A) and two triples into a hexagon (5B). 1 is a schematic view of a spinning line used in Example 1. FIG. 1 is a schematic diagram of a skiving process used in Example 1. FIG. 2 is a scanning electron micrograph of the porous film produced in Example 1 at a magnification of three levels. FIG. 6 is a schematic side view and end-on view of a billet rotary skiving created by integrating the six trapezoidal sections shown in FIG. 5. Figure 2 is a schematic illustration of a skiving cylindrical billet made from stacked fiber mats using a solid capping film in two directions (front and back end caps not shown). Also shown is a solid capping film between the wafers around, across and through the billet. FIG. 11 is a schematic illustration of an annular sector of fused fibers, one of many segments stacked to make the billet shown in FIG. A hollow fiber (12A) having inner and outer sheaths and a cross-section of a fiber-on-end membrane (12B) made from them are depicted.

Claims (10)

  A fiber-on-end material produced by skiving a material of a desired thickness from a billet comprising a plurality of fibers arranged parallel to each other and fused, at least one step in billet production or skiving The fiber-on-end material as described above, wherein is carried out in a continuous manner and the optionally skived material is contacted with a solvent to dissolve the fiber components.   The fiber-on-end material according to claim 1, which is a porous membrane or a capillary array.   The fiber-on-end material according to claim 1, which is a film having microprojections.   The fiber-on-end material of claim 1, wherein the plurality of fibers comprises a mixture of fibers having at least two different defined diameters.   A central core in which the fibers are air or a solid that can be dissolved away; an inner sheath that is rigid and performs a specific function; and an outer sheath that can be fused at a lower temperature than the inner sheath or core material; The fiber-on-end material of claim 1, comprising a tricomponent fiber comprising   A central core where the fibers are air or a solid that can be dissolved away; an inner sheath that changes volume in the presence of an external stimulus; and an outer sheath that can be fused at a lower temperature than the inner sheath or core material The fiber-on-end material of claim 1, comprising a tricomponent fiber comprising a sheath.   A product comprising the fiber-on-end material of claim 1.   Clothes, hats, hoods, masks, gowns, coats, outerwear, shirts, bonnets, pants, gloves, boots, shoes, shoes or boot covers, socks, rain gear, ski pants, protective enclosures, protective coveralls, protective clothing , Protective coat, protective jacket, limited use protective clothing, protective gloves, protective socks, safety boots, safety covers for shoes or boots, protective pants, protective hood, safety cap or other protective head cover, protective mask, protective 8. A product according to claim 7, which is one item of clothing or protective cover selected from the group consisting of shirts, medical clothing, surgical masks, medical or surgical gowns or slippers.   4. At least one chemical moiety along the capillary wall that contains active or reactive chemical moieties that selectively bind to specific species and chemical species that need to be purified or removed from the fluid. A method for affinity separation of species in a fluid comprising flowing fluid through the capillaries of a fiber-on-end capillary array.   3. At least two parallel claims, wherein the capillaries in each array have essentially the same slope, and the slope of the capillaries in one array is different from the slope of the capillaries in at least one other array. An article comprising the described capillary array.

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