WO2005087673A1 - Method for the production of fibres by means of extrusion with a focusing gas in subsonic regime - Google Patents

Method for the production of fibres by means of extrusion with a focusing gas in subsonic regime Download PDF

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Publication number
WO2005087673A1
WO2005087673A1 PCT/ES2005/000117 ES2005000117W WO2005087673A1 WO 2005087673 A1 WO2005087673 A1 WO 2005087673A1 ES 2005000117 W ES2005000117 W ES 2005000117W WO 2005087673 A1 WO2005087673 A1 WO 2005087673A1
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WIPO (PCT)
Prior art keywords
fluid
fiber
nozzle
focusing
focusing fluid
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PCT/ES2005/000117
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Spanish (es)
French (fr)
Inventor
Alfonso Miguel GANÃN CALVO
Miguel PÉREZ-SABORID SÁNCHEZ-PASTOR
José María LÓPEZ-HERRERA SÁNCHEZ
Miguel Ángel HERRADA GUTIÉRREZ
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Universidad De Sevilla
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Publication of WO2005087673A1 publication Critical patent/WO2005087673A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/022—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from molten glass in which the resultant product consists of different sorts of glass or is characterised by shape, e.g. hollow fibres, undulated fibres, fibres presenting a rough surface
    • C03B37/023—Fibres composed of different sorts of glass, e.g. glass optical fibres, made by the double crucible technique
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
    • C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres

Definitions

  • the method described in this invention is applied to the manufacture of fibers by combining two overlapping actions.
  • the fiber material from here, fiber material or constituent fluid
  • another fluid from here, focusing fluid
  • the focusing fluid is flowed subsonically to the focusing material with the fiber material through a small convergent nozzle.
  • the solidification of the fiber material, which is jetted out of the nozzle is promoted by one of the following three procedures: cooling, solvent evaporation, or component reaction. It is an essential feature of the invention that the focusing fluid circulates through the nozzle in a subsonic regime, specifying the precise speed limits allowed for the focusing fluid in the nozzle if it is desired to avoid jet instabilities.
  • thermoplastic materials are used which, once cast, are subjected to extrusion through a narrow hole, followed by solidification in the ambient air.
  • the filament or fiber thus obtained then passes to a post-processing unit that, depending on the use to which the product is intended, will perform the corresponding spinning, stretching, twisting, curling, coating and other tasks.
  • optical fibers using silicon dioxide, quartz or silica as raw material. Doped additives are incorporated during the manufacturing process, which allow the value of the refractive indexes of the core and the fiber optic coating to be modified.
  • high optical transparency materials are required, so the silicon dioxide used must ensure a high degree of purity.
  • the fiber optic extrusion processes are based on a preform, that is, a solid doped silicon dioxide cylinder that provides as raw material for
  • the preform is extruded.
  • a part of the preform is subjected to heating and traction, the fiber being extracted from it, with the desired section and production rate.
  • the induction furnace used must heat the fiber material without causing contamination problems and ensuring reliable thermal control.
  • textile synthetic fiber polymers, nylon, aquatic, rayon, viscose
  • extrusion processes of molten polymers through a row (spinneret, strainer), that is, a die with one or several small holes.
  • the filaments thus obtained are stretched and rolled in a coil.
  • the ways of processing the polymer are diverse, and the choice of technology depends on the nature of the polymer.
  • the main options, all based on direct extrusion processes, are:
  • the filaments thus produced are subsequently subjected to cold stretching that reorder the crystalline structure in the longitudinal direction.
  • extrusion fiber production is also important.
  • the granular raw material (flours and the like) is transported, mixed, kneaded, cooked, pasteurized, pressurized, solubilized, molded and / or expanded.
  • Continuous presses for extrusion of pasta are well known. To do this, it has the mechanical action of one or two screws that rotate inside a container at rest.
  • agribusiness it is worth mentioning the production of breakfast cereals, as well as noodles and spaghetti.
  • fibers for example, polypropylene
  • suture threads surgical material and personal hygiene equipment
  • the method described in this invention is applied to the manufacture of fibers of a solid material from its fluid or ductile, molten or plastic form (high viscosity liquid) by heating, or from its more or less form dissolved in sol-gel phase, or from its components in fluid or ductile, molten or plastic phase.
  • the fiber is produced after the following steps: a) Conformation of the fiber material (from here, fiber material or constituent fluid) in its fluid or ductile phase by means of another fluid (from here, focusing fluid ) immiscible with said fluid or ductile phase, for example a gas, which is flowed in a subsonic regime concentrically with the fiber material through a small convergent nozzle. b) Solidification of the fiber material by (i) cooling, (ii) evaporation of the solvent, or (iii) reaction of the components that produce the final solid material of the fiber.
  • the focusing fluid is of lower viscosity and density than the fiber constituent material, and must be of a nature that allows its rapid removal after being expelled with the fiber by the nozzle.
  • a focusing fluid is used that transmits to the fiber material that the necessary mechanical stresses are being extracted so that it is stretched and ⁇ -decreases its diameter or transverse dimension.
  • the viscous fluid that is to be shaped as a fiber is fed into a pressure chamber, on which the focusing fluid is also fed, and both fluids are made to flow concentrically (in the center the constituent fluid) through of a convergent nozzle.
  • the focusing fluid which flows subsonically and concentrically with the fiber through the extrusion nozzle, transmits its pressure to the fiber during said nozzle.
  • the pressure distribution of the focusing fluid must guarantee the absence of the axilsymmetric and asymmetric instabilities generally associated with the stretching of fibers, and for this the speed of said fluid must be between two limits: the lower limit corresponds to the minimum speed for which axilsymmetric instabilities would be suppressed; the
  • SUBSTITUTE SHEET RULE 26 upper limit corresponds to the maximum speed for which asymmetric or "whip" instabilities would not appear. Specifically, the speed of the focusing fluid at each point of the nozzle must be less than:
  • the speed of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the fiber material, multiplied by the final output speed of the fiber, divided by the gas density (before entering the nozzle) and divided by the length of the nozzle.
  • the shape of the nozzle, convergent, must be such that the focusing fluid is accelerated producing a pressure distribution whose axial dependence is approximately exponential, that is, directly proportional to:
  • L is the axial length of the nozzle
  • x the axial coordinate measured from the entry into the nozzle
  • ⁇ a dimensionless parameter between 3 and 8.
  • the focusing fluid can contribute, by virtue of its intrinsic properties, to control or favor the fiber solidification process.
  • a gas is used as the focusing fluid, its expansion in the nozzle causes its cooling and consequently, by means of energy transfer mechanisms, the cooling of the fiber material itself. This allows the control of the solidification rate of the material and its final properties if the material is being processed in the ductile phase by heating.
  • a solvent defect fluid is used as the focusing fluid that keeps the fiber material in a ductile or sol-gel phase, the additional effect of the focusing fluid is its contribution to extracting excess solvent from the fiber material (by mass transfer mechanisms), so that the fiber solidification process can be controlled.
  • a fluid with a chemical component catalyst or accelerator of the reaction of the components of the fiber material is used as the focusing fluid, similarly, by means of mass transfer mechanisms, the solidification process of the fiber.
  • the described procedure is applicable to any type of ductile material that is susceptible to subsequent solidification after forming it in the form of fiber. Therefore, its application is enormously wide, in sectors such as the manufacture of optical fiber, capillary micro-tubes, polymeric, ceramic or metallic fibers.
  • the present invention ensures the following advantages: o It provides a high degree of control over the fiber diameter. o It allows exceeding the maximum speed limit of fiber extraction associated with the instability of said fiber, o It avoids intense tangential stresses and frequent jamming problems in direct extrusion.
  • the focusing fluid can contribute, by virtue of its intrinsic properties, to control or favor the fiber solidification process.
  • the present invention ensures the following advantages: a Extension to various fiber production fields, exceeding the optical fiber limit of the procedure described in DI. "Applicability to constituent fluids of different viscosity. The highly viscous nature of the fiber raw material is not essential.” Specification of a range of flow velocities for the focusing fluid within the subsonic regime, with a precision of limits that allows prediction the absence of instabilities in the flow of the emerging fiber of the device.
  • the object of the invention is a process for producing a fiber starting from a cylindrical preform, by means of: a) Introduction of the first of the ends of the cylindrical preform into a pressure chamber so that the axis of the cylinder is aligned with a longitudinal axis; b) Exposure of the first end of the preform to a treatment that allows the ductility of the preform at this first end; c) Application of a pressure by means of a focusing fluid, which is introduced into a pressurized chamber through an entrance to that effect in said chamber; said focusing fluid flows along the predominance and towards the first end of said preform, forcing this first ductile end of the preform through an outlet nozzle of the pressure chamber; in said nozzle the concentric flow of the ductile end of the preform and the focusing fluid occurs; said nozzle is aligned
  • SUBSTITUTE SHEET RULE 26 with the axis of the preform and is located downstream in the flow direction of the focusing fluid; said focusing fluid helps to expel a fiber from the exit orifice of the pressure chamber, resulting in a reduction in the transverse dimension of the fiber with respect to the transverse dimension that the preform has inside the pressure chamber;
  • This procedure differs from the one described in DI because the speed of the focusing fluid at each point of the nozzle is lower than the speed of sound propagation within the focusing fluid at that point, that is, it occurs in a subsonic regime; and the speed of the focusing fluid at each point of the nozzle is also less than 0.25 times the viscosity of fiber material in said ductile state divided by the geometric mean of the densities of the fiber material and the focusing fluid, and divided by the final radius of the fiber that you want to obtain; on the other hand, the velocity of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the fiber material in said ductile state, multiplied by the exit velocity of the fiber, divided by the density of the gas before entering the nozzle and divided by the length of the nozzle.
  • the object of the present invention is also a process for producing a fiber using a constituent fluid as a supplier of raw material for said fiber, by the following steps: a) Extrusion of a current of said constituent fluid so that it flows from a power source into a pressure chamber in which a focusing fluid is located; b) Supply of focusing fluid to the pressure chamber so that said fluid, which is introduced into said chamber through an inlet opening, exits through an outlet nozzle of the pressure chamber, said nozzle located downstream of the flow of viscous fusion fluid; c) the focusing fluid surrounds the jet of constituent fluid so that said jet leaves the pressurized chamber, surrounded by the focusing fluid, by the nozzle of the same; the transverse dimension of said jet at the outlet of said nozzle is smaller than that of the power supply; d) Solidification of said jet to produce a fiber, which moves away from the nozzle at a certain output speed;
  • SUBSTITUTE SHEET RULE 26 This procedure is characterized in that the speed of the focusing fluid at each point of the nozzle is lower than the speed of sound propagation within the focusing fluid at that point, that is, it occurs in a subsonic regime; and the speed of the focusing fluid at each point of the nozzle is also less than 0.25 times the viscosity of constituent fluid divided by the geometric mean of the densities of the constituent fluid and the focusing fluid, and divided by the final radius of the fiber that you want be obtained; on the other hand, the velocity of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the constituent fluid, multiplied by the speed of exit of the fiber, divided by the density of the gas before entering in the nozzle and divided by the length of the nozzle.
  • the object of the invention is also a process for producing a fiber like the one above, characterized in that the constituent fluid is a viscous fluid obtained by melting another solid substance.
  • a process for producing a fiber according to the above is object of the invention, in which the constituent fluid is composed of two or more components in the form of liquids of which at least one will be viscous, so that said components , which are introduced into said pressure chamber through one or more inlet openings, are in intimate contact in the pressure chamber before being extruded as a single viscous fluid surrounded by the focusing fluid through said outlet nozzle of the pressure chamber, which is located downstream of the flow of said components in intimate contact.
  • the object of the invention a device like the previous one, characterized in that the components react chemically in their flow along the nozzle and after being expelled through it in the form of a jet together with the focusing fluid, so that finally the curing of the mixture of components and the solidification of the fiber takes place.
  • Another object of the invention is a process for producing a fiber in which the constituent fluid is a solution of the raw material of said fiber in a solvent, so that the solution is a viscous or sol-gel phase fluid.
  • the object of the invention is also a process for producing a fiber according to the above, characterized in that said solution totally or partially loses the solvent in its flow along the nozzle and after being expelled through it in the form of a jet together with the focusing fluid, so that the solidification of the fiber finally occurs.
  • the object of the invention is a process for producing a fiber based on the foregoing, in which the solvent concentrate in said solution is controlled by the focusing fluid by means of chemical mass transfer phenomena.
  • Figure 1 shows a device adapted to the described process for producing a fiber using a constituent fluid as a supplier of raw material for said fiber, showing the following aspects of the invention: a) power supply of constituent fluid or solid preform (7 ) into a pressure chamber (1) in which a focusing fluid is located; b) inlet opening (2) for the introduction of focusing fluid; c) outlet nozzle (3) of the pressure chamber; d) jet at the outlet of the nozzle.

Abstract

The invention relates to a method which is intended for the production of fibres and which combines two operations. According to the invention, the first operation comprises the formation of the material of the fibre (referred to hereafter as fibre material or constituent fluid) in the fluid or ductile phase thereof using another fluid (referred to hereafter as focusing fluid) which is immiscible with said fluid or ductile phase, e.g. a gas. For said purpose, the focusing fluid is made to flow concentrically with the fibre material through a small converging nozzle. The second operation, which is performed simultaneously with the aforementioned coaxial flow, comprises the solidification of the fibre material leaving the nozzle in the form of a jet, using one of the following three methods: cooling, evaporation of the solvent or reaction of the components. The invention is essentially characterised in that the focusing fluid flows through the nozzle in the subsonic regime, the precise velocity limits permitted for the focusing fluid in the nozzle being specified in order to prevent irregular fluctuations in the jet.

Description

PROCEDIMIENTO PARA LA FABRICACIÓN DE FIBRAS MEDIANTE EXTRUSIÓN CON UN GAS ENFOCANTE EN RÉGIMEN SUBSÓNICOPROCEDURE FOR THE MANUFACTURE OF FIBERS BY EXTRUSION WITH A FOCUSING GAS IN SUBSONIC REGIME
OBJETOOBJECT
El método que se describe en esta invención se aplica a la fabricación de fibras mediante la combinación de dos acciones superpuestas. Por un lado, se conforma el material de la fibra (a partir de aquí, material de la fibra o fluido constituyente) en su fase fluida o dúctil por medio de otro fluido (a partir de aquí, fluido enfocante) inmiscible con dicha fase fluida o dúctil, por ejemplo un gas. Para ello se hace fluir en régimen subsónico al fluido enfocante concéntricamente con el material de la fibra a través de una pequeña tobera convergente. Por otro lado, y simultáneamente al citado flujo coaxial, se propicia la solidificación del material de la fibra, que sale en forma de chorro de la tobera, por uno de los tres procedimientos siguientes: enfriamiento, evaporación del solvente, o reacción de componentes. Es característica esencial de la invención el que el fluido enfocante circula por la tobera en régimen subsónico, especificándose los límites precisos de velocidad permitidos para el fluido enfocante en la tobera si se desean evitar las inestabilidades del chorro.The method described in this invention is applied to the manufacture of fibers by combining two overlapping actions. On the one hand, the fiber material (from here, fiber material or constituent fluid) is formed in its fluid or ductile phase by means of another fluid (from here, focusing fluid) immiscible with said fluid phase or ductile, for example a gas. For this, the focusing fluid is flowed subsonically to the focusing material with the fiber material through a small convergent nozzle. On the other hand, and simultaneously with the aforementioned coaxial flow, the solidification of the fiber material, which is jetted out of the nozzle, is promoted by one of the following three procedures: cooling, solvent evaporation, or component reaction. It is an essential feature of the invention that the focusing fluid circulates through the nozzle in a subsonic regime, specifying the precise speed limits allowed for the focusing fluid in the nozzle if it is desired to avoid jet instabilities.
ESTADO DE LA TÉCNICASTATE OF THE TECHNIQUE
La mayor parte de las fibras que se usan hoy día son sintéticas, y para su manufactura se acude a materiales termoplásticos que, una vez fundidos, son sometidos a extrusión a través de un orificio estrecho, produciéndose seguidamente su solidificación en el aire ambiente. El filamento o la fibra así obtenida pasa seguidamente a una unidad de post-procesamiento que, dependiendo del uso a que se destina el producto, realizará las correspondientes tareas de hilado, estirado, torcido, ovillado, revestimiento y otras.Most of the fibers that are used today are synthetic, and for their manufacture, thermoplastic materials are used which, once cast, are subjected to extrusion through a narrow hole, followed by solidification in the ambient air. The filament or fiber thus obtained then passes to a post-processing unit that, depending on the use to which the product is intended, will perform the corresponding spinning, stretching, twisting, curling, coating and other tasks.
Las aplicaciones son numerosas y se centran el hilado de resinas, polímeros o vidrio con fines industriales (fibra óptica, elementos estructurales, industria textil). Las fibras son también utilizadas como ingrediente de materiales compuestos, como los polímeros reforzados o los composites. Los procedimientos de extrusión presentan numerosas ventajas, entre las que destacan sus costos de producción moderados, su escaso requerimiento de espacio, simplicidad conceptual de diseño, reducida generación de desechos y funcionamiento como proceso continuo.The applications are numerous and focus the spinning of resins, polymers or glass for industrial purposes (fiber optics, structural elements, textile industry). Fibers are also used as an ingredient in composite materials, such as reinforced polymers or composites. Extrusion procedures have numerous advantages, among which stand out their moderate production costs, their low space requirement, conceptual simplicity of design, reduced waste generation and operation as a continuous process.
De particular importancia es la fabricación de fibras ópticas, empleándose para ello como materia prima dióxido de silicio, cuarzo o sílice. Durante el proceso de fabricación se incorporan aditivos de dopado, que permiten modificar el valor de los índices de refracción del núcleo y del revestimiento de la fibra óptica. Para la fabricación de fibra óptica se requieren materiales de alta transparencia óptica, por lo que el dióxido de silicio utilizado debe asegurar un alto grado de pureza.Of particular importance is the manufacture of optical fibers, using silicon dioxide, quartz or silica as raw material. Doped additives are incorporated during the manufacturing process, which allow the value of the refractive indexes of the core and the fiber optic coating to be modified. For the manufacture of optical fiber, high optical transparency materials are required, so the silicon dioxide used must ensure a high degree of purity.
Los procedimientos de extrusión de fibra óptica se basan en una preforma, es decir, un dlindro macizo de dióxido de silicio dopado que proporciona como materia prima para laThe fiber optic extrusion processes are based on a preform, that is, a solid doped silicon dioxide cylinder that provides as raw material for
elaboración de la fibra. Seguidamente se procede a la extrusión de la preforma. Para ello, una parte de la preforma es sometida a calentamiento y tracción, extrayéndose de ella la fibra, con la sección y tasa de producción deseadas. El horno de inducción empleado debe calentar el material de la fibra sin ocasionar problemas de contaminación y asegurando un control térmico fiable.fiber processing Next, the preform is extruded. For this, a part of the preform is subjected to heating and traction, the fiber being extracted from it, with the desired section and production rate. The induction furnace used must heat the fiber material without causing contamination problems and ensuring reliable thermal control.
La manufactura de fibra sintética textil (poliéster, nylon, acrüicos, rayón, viscosa) se basa asimismo en procesos de extrusión de polímeros fundidos a través de una hilera (spinneret, strainer), es decir, un dado con uno o varios pequeños orificios. Los filamentos así conseguidos se estiran y se enrollan en una bobina. Son diversos los modos de procesar el polímero, y la elección de tecnología depende de la naturaleza de éste. Las principales opciones, basadas todas ellas es procesos de extrusión directa, son:The manufacture of textile synthetic fiber (polyester, nylon, aquatic, rayon, viscose) is also based on extrusion processes of molten polymers through a row (spinneret, strainer), that is, a die with one or several small holes. The filaments thus obtained are stretched and rolled in a coil. The ways of processing the polymer are diverse, and the choice of technology depends on the nature of the polymer. The main options, all based on direct extrusion processes, are:
• Hilado fundido (rnelt-spinning process): el polímero es sometido a calentamiento, fusión y bombeo a través de la hilera. Los filamentos emergentes son estirados y se enfrían en el aire exterior, siendo luego recogidos y devanados en una bobina. • Hilado en seco (clry-spinning process): la materia prima es una disolución cuyo solvente es extraído por evaporación. El proceso de extrusión se combina con el paso del material de fibra por una cámara caliente o un flujo a contracorriente de aire cálido, etapa en la que el solvente se evapora. • Hilado húmedo ( et-spinning process): el polímero está presente como disolución, con un solvente no volátil. Los dos o más componentes de la disolución son separados químicamente, mediante el paso del material extruido a través de un baño coagulante donde se produce la precipitación del polímero en forma de hilos.• Molten spinning (rnelt-spinning process): the polymer is subjected to heating, melting and pumping through the row. The emerging filaments are stretched and cooled in the outside air, then being collected and wound in a coil. • Dry spinning (clry-spinning process): the raw material is a solution whose solvent is removed by evaporation. The extrusion process is combined with the passage of the fiber material through a hot chamber or a counterflow of warm air, a stage in which the solvent evaporates. • Wet spinning (et-spinning process): the polymer is present as a solution, with a non-volatile solvent. The two or more components of the solution are separated chemically, by passing the extruded material through a coagulating bath where the precipitation of the polymer in the form of threads occurs.
Los filamentos así producidos se someten posteriormente a estirados en frío que reordenan la estructura cristalina en dirección longitudinal.The filaments thus produced are subsequently subjected to cold stretching that reorder the crystalline structure in the longitudinal direction.
En el sector agroalimentario, la producción de fibras por extrusión tiene también importancia. Mediante la extrusión, la materia prima granular (harinas y similares) es transportada, mezclada, amasada, cocida, pasteurizada, presurizada, solubilizada, moldeada y/o expandida. Son bien conocidas las prensas continuas para la extrusión de pastas alimenticias. Para ello se cuenta con la acción mecánica de uno o dos tornillos que giran dentro de un recipiente en reposo. En la agroindustria cabe citar la producción de cereales para el desayuno, así como de fideos y espaguetis.In the agri-food sector, extrusion fiber production is also important. By extrusion, the granular raw material (flours and the like) is transported, mixed, kneaded, cooked, pasteurized, pressurized, solubilized, molded and / or expanded. Continuous presses for extrusion of pasta are well known. To do this, it has the mechanical action of one or two screws that rotate inside a container at rest. In agribusiness, it is worth mentioning the production of breakfast cereals, as well as noodles and spaghetti.
En la industria médica, por otra parte, son asimismo frecuentes las fibras (por ejemplo, de polipropileno), aplicadas en la producción de hilos de sutura, material quirúrgico y pertrechos de higiene personal.In the medical industry, on the other hand, fibers (for example, polypropylene), applied in the production of suture threads, surgical material and personal hygiene equipment, are also frequent.
La extrusión de polímeros conductores está siendo investigada en electrónica dado su posible utilidad en la producción de transistores de efecto de campo (FET) y en diodos emisores de luz. En esta línea se han registrado avances en el estudio de transistores mediante nanofibras poliméricas: véase el artículo "Field effect conductance of conducting polymer nanofibers" (p. 2674-2680), Jeffrey A. Merlo, C. Daniel Frisbie, Journal of Polymer Science Part B: Polymer Physics, Nolume 41, Issue 21 (1 Νovember 2003).The extrusion of conductive polymers is being investigated in electronics given its possible utility in the production of field effect transistors (FET) and in light emitting diodes. Along these lines, advances have been made in the study of transistors using polymeric nanofibers: see the article "Field effect conductivity of conducting polymer nanofibers" (p. 2674-2680), Jeffrey A. Merlo, C. Daniel Frisbie, Journal of Polymer Science Part B: Polymer Physics, Nolume 41, Issue 21 (1 Νovember 2003).
En numerosas aplicaciones de las fibras, es esencial asegurar un estricto control sobre la estructura cristalina o amorfa de las cadenas moleculares del material de fibra, que, dependiendo de las etapas de proceso a que se ~ve sometida, experimenta reordenaciones muy significativas para el posterior uso de la fibra. En efecto, de dicha estructura depende la posterior conductividad térmica u óptica, así como la resistencia mecánica de la fibra.In numerous fiber applications, it is essential to ensure strict control over the crystalline or amorphous structure of the molecular chains of the fiber material, which, depending on the process stages to which it is subjected, undergoes very significant rearrangements for subsequent fiber use Indeed, the subsequent thermal or optical conductivity depends on said structure, as well as the mechanical resistance of the fiber.
Se han descrito procedimientos, orientados a la producción de fibra óptica, en los cuales es esencial el auxilio de una corriente envolvente de fluido enfocante. Véase para ello la patente WO 01/69289 (Dl= "Methods for producing optical fiber by focusing high viscosity liquid"). La presente invención es un desarrollo independiente y posterior del estado de la técnica alcanzado con dicha patente, en el que se avanza decisivamente hacia la generalización del procedimiento descrito en DI.Procedures, oriented to the production of fiber optics, have been described in which the aid of a focusing current of focusing fluid is essential. For this, see WO 01/69289 (Dl = "Methods for producing optical fiber by focusing high viscosity liquid"). The present invention is an independent and subsequent development of the state of the art achieved with said patent, in which decisive progress is made towards the generalization of the procedure described in DI.
HOJA DE SUSTITUCIÓN REGLA 26 DESCRIPCIÓN DETALLADA DE LA INVENCIÓNSUBSTITUTE SHEET RULE 26 DETAILED DESCRIPTION OF THE INVENTION
El método que se describe en esta invención se aplica a la fabricación de fibras de un material sólido a partir de su forma fluida o dúctil, fundida o plástica (líquido de alta viscosidad) por calentamiento, o bien a partir de su forma más o menos disuelta en fase de sol-gel, o bien a partir de sus componentes en fase fluida o dúctil, fundida o plástica. La fibra se produce tras los siguientes pasos: a) Conformación del material de la fibra (a partir de aquí, material de la fibra o fluido constituyente) en su fase fluida o dúctil por medio de otro fluido (a partir de aquí, fluido enfocante) inmiscible con dicha fase fluida o dúctil, por ejemplo un gas, que se hace fluir en régimen subsónico concéntricamente con el material de la fibra a través de una pequeña tobera convergente. b) Solidificación del material de la fibra por (i) enfriamiento, (ii) evaporación del solvente, o (iii) reacción de los componentes que producen el material sólido final de la fibra.The method described in this invention is applied to the manufacture of fibers of a solid material from its fluid or ductile, molten or plastic form (high viscosity liquid) by heating, or from its more or less form dissolved in sol-gel phase, or from its components in fluid or ductile, molten or plastic phase. The fiber is produced after the following steps: a) Conformation of the fiber material (from here, fiber material or constituent fluid) in its fluid or ductile phase by means of another fluid (from here, focusing fluid ) immiscible with said fluid or ductile phase, for example a gas, which is flowed in a subsonic regime concentrically with the fiber material through a small convergent nozzle. b) Solidification of the fiber material by (i) cooling, (ii) evaporation of the solvent, or (iii) reaction of the components that produce the final solid material of the fiber.
El fluido enfocante es de menor viscosidad y densidad que el material constituyente de la fibra, y ha de ser de naturaleza tal que permita su eliminación rápida tras ser expulsado con la fibra por la tobera.The focusing fluid is of lower viscosity and density than the fiber constituent material, and must be of a nature that allows its rapid removal after being expelled with the fiber by the nozzle.
En esta invención se utiliza un fluido enfocante que transmite al material de la fibra que se está extrayendo los esfuerzos mecánicos necesarios para que se estire y ά-isminuya su diámetro o dimensión transversal. Para ello, se alimenta el fluido viscoso que se va a conformar en forma de fibra hacia una cámara de presión, sobre la cual se alimenta también el fluido enfocante, y ambos fluidos se hacen fluir concéntricamente (en el centro el fluido constituyente) a través de una tobera convergente. De esta forma, el fluido enfocante, que fluye en régimen subsónico y concéntricamente con la fibra por la tobera de extrusión, transmite durante el recorrido por dicha tobera su presión a la fibra.In this invention a focusing fluid is used that transmits to the fiber material that the necessary mechanical stresses are being extracted so that it is stretched and ά-decreases its diameter or transverse dimension. To do this, the viscous fluid that is to be shaped as a fiber is fed into a pressure chamber, on which the focusing fluid is also fed, and both fluids are made to flow concentrically (in the center the constituent fluid) through of a convergent nozzle. In this way, the focusing fluid, which flows subsonically and concentrically with the fiber through the extrusion nozzle, transmits its pressure to the fiber during said nozzle.
La distribución de presiones del fluido enfocante ha de garantizar la ausencia de las inestabilidades axilsimétricas y asimétricas generalmente asociadas con el estiramiento de fibras, y para ello la velocidad del mencionado fluido debe estar entre dos límites: el límite inferior corresponde a la mínima velocidad para la cual se suprimirían las inestabilidades axilsimétricas; elThe pressure distribution of the focusing fluid must guarantee the absence of the axilsymmetric and asymmetric instabilities generally associated with the stretching of fibers, and for this the speed of said fluid must be between two limits: the lower limit corresponds to the minimum speed for which axilsymmetric instabilities would be suppressed; the
HOJA DE SUSTITUCIÓN REGLA 26 límite superior corresponde a la máxima velocidad para la cual no aparecerían inestabilidades asimétricas o "de látigo". Concretamente, la velocidad del fluido enfocante en cada punto de la tobera debe ser inferior a:SUBSTITUTE SHEET RULE 26 upper limit corresponds to the maximum speed for which asymmetric or "whip" instabilities would not appear. Specifically, the speed of the focusing fluid at each point of the nozzle must be less than:
• La velocidad de propagación del sonido en el seno del fluido enfocante en ese punto (régimen subsónico), • 0.25 veces la viscosidad de líquido dividida por la media geométrica de las densidades del material de la fibra y el fluido enfocante, y dividida por el radio final de la fibra que quiere obtenerse.• The speed of sound propagation within the focusing fluid at that point (subsonic regime), • 0.25 times the viscosity of the liquid divided by the geometric mean of the densities of the fiber material and the focusing fluid, and divided by the final radius of the fiber you want to obtain.
Por otra parte, la velocidad del fluido enfocante en cada punto de la tobera debe ser superior a la raíz cuadrada de 2 veces la viscosidad del material de la fibra, multiplicada por la velocidad de salida final de la fibra, dividida por la densidad del gas (antes de entrar en la tobera) y dividida por la longitud de la tobera.On the other hand, the speed of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the fiber material, multiplied by the final output speed of the fiber, divided by the gas density (before entering the nozzle) and divided by the length of the nozzle.
La forma de la tobera, convergente, ha de ser tal que el fluido enfocante se acelere produciendo una distribución de presiones cuya dependencia axial sea aproximadamente exponencial, esto es, directamente proporcional a:The shape of the nozzle, convergent, must be such that the focusing fluid is accelerated producing a pressure distribution whose axial dependence is approximately exponential, that is, directly proportional to:
-mil-thousand
siendo L la longitud axial de la tobera, x la coordenada axial medida a partir de la entrada en la tobera y λ un parámetro adimensional comprendido entre 3 y 8.where L is the axial length of the nozzle, x the axial coordinate measured from the entry into the nozzle and λ a dimensionless parameter between 3 and 8.
Las características del flujo del fluido enfocante anteriormente enunciadas confieren las ventajas siguientes:The flow characteristics of the focusing fluid mentioned above confer the following advantages:
1- El consumo energético del proceάtmiento aquí descrito es menor que el de cualquier otro método que use gas en régimen supersónico como fluido enfocante, 2- Se eliminan todo tipo de inestabilidades en la formación de la fibra (tales como irregularidades en la sección transversal, o los movimientos laterales, "de látigo" o helicoidales) sin restricción en la velocidad de salida de la fibra, con lo que se puede incrementar sustancialmente la productividad manteniendo un diámetro final de la fibra extremadamente delgado (en el rango de la miera).1- The energy consumption of the procedure described here is lower than that of any other method that uses supersonic regime gas as a focusing fluid, 2- All kinds of instabilities in fiber formation (such as irregularities in the cross-section, are eliminated, or lateral movements, "of whip" or helical) without restriction in the speed of exit of the fiber, with what can increase substantially the productivity maintaining a final diameter of the extremely thin fiber (in the range of the miera).
HOJA DE SUSTITUCIÓN REGLA 26 Asimismo, el fluido enfocante puede contribuir, en virtud de sus propiedades intrínsecas, a controlar o a favorecer el proceso de solidificación de fibra. o Si se utiliza un gas como fluido enfocante, su expansión en la tobera provoca su enfriamiento y consecuentemente, por mecanismos de transferencia de energía, el enfriamiento del propio material de la fibra. Esto permite el control de la velocidad de solidificación del material y sus propiedades finales si el material se está procesando en fase dúctil por calentamiento. o Si se utiliza como fluido enfocante un fluido con defecto del solvente que mantiene al material de la fibra en estado dúctil o en fase sol-gel, el efecto adicional del fluido enfocante es su contribución a extraer del material de la fibra el exceso de solvente (por mecanismos de transferenda de masa), de manera que se puede controlar el proceso de solidificación de la fibra. o Si, por otra parte, se utiliza como fluido enfocante un fluido con un componente químico catalizador o acelerante de la reacción de los componentes del material de la fibra, análogamente, mediante mecanismos de transferencia de masa, se puede controlar el proceso de solidificación de la fibra.SUBSTITUTE SHEET RULE 26 Likewise, the focusing fluid can contribute, by virtue of its intrinsic properties, to control or favor the fiber solidification process. o If a gas is used as the focusing fluid, its expansion in the nozzle causes its cooling and consequently, by means of energy transfer mechanisms, the cooling of the fiber material itself. This allows the control of the solidification rate of the material and its final properties if the material is being processed in the ductile phase by heating. o If a solvent defect fluid is used as the focusing fluid that keeps the fiber material in a ductile or sol-gel phase, the additional effect of the focusing fluid is its contribution to extracting excess solvent from the fiber material (by mass transfer mechanisms), so that the fiber solidification process can be controlled. o If, on the other hand, a fluid with a chemical component catalyst or accelerator of the reaction of the components of the fiber material is used as the focusing fluid, similarly, by means of mass transfer mechanisms, the solidification process of the fiber.
El procedimiento descrito es aplicable a cualquier tipo de material dúctil que sea susceptible de una posterior solidificación tras su conformado en forma de fibra. Por ello, su aplicación es enormemente amplia, en sectores tales como la fabricación de fibra óptica, micro-tubos capilares, fibras poliméricas, cerámicas o metálicas.The described procedure is applicable to any type of ductile material that is susceptible to subsequent solidification after forming it in the form of fiber. Therefore, its application is enormously wide, in sectors such as the manufacture of optical fiber, capillary micro-tubes, polymeric, ceramic or metallic fibers.
Con respecto a las tecnologías de extrusión directa extendidas en el sector, la presente invención asegura las siguientes ventajas: o Proporciona un alto grado de control sobre el diámetro de fibra. o Permite rebasar el límite de veloddad máxima de extracción de fibra asociado a la inestabilidad de dicha fibra, o Evita los intensos esfuerzos tangenciales y los problemas de atasco frecuentes en la extrusión directa.With respect to the direct extrusion technologies extended in the sector, the present invention ensures the following advantages: o It provides a high degree of control over the fiber diameter. o It allows exceeding the maximum speed limit of fiber extraction associated with the instability of said fiber, o It avoids intense tangential stresses and frequent jamming problems in direct extrusion.
HOJA DE SUSTITUCIÓN REGLA 26 o El fluido enfocante puede contribuir, en virtud de sus propiedades intrínsecas, a controlar o a favorecer el proceso de solidificación de fibra.SUBSTITUTE SHEET RULE 26 o The focusing fluid can contribute, by virtue of its intrinsic properties, to control or favor the fiber solidification process.
Con respecto a la patente anterior DI, la presente invención asegura las siguientes ventajas: a Extensión a diversos campos de producción de fibras, superando la limitadón a fibra óptica del procedimiento descrito en DI. " Aplicabilidad a fluidos constituyentes de diversa viscosidad. No es imprescindible el carácter altamente viscoso de la materia prima de la fibra. " Especificación de un rango de veloddades de flujo para el fluido enfocante dentro del régimen subsónico, con una precisión de límites que permite predecir la ausencia de inestabilidades en el flujo de la fibra emergente del dispositivo.With respect to the previous DI patent, the present invention ensures the following advantages: a Extension to various fiber production fields, exceeding the optical fiber limit of the procedure described in DI. "Applicability to constituent fluids of different viscosity. The highly viscous nature of the fiber raw material is not essential." Specification of a range of flow velocities for the focusing fluid within the subsonic regime, with a precision of limits that allows prediction the absence of instabilities in the flow of the emerging fiber of the device.
Las reivindicaciones de la presente invención se exponen partiendo del estado de la técnica definido por la patente DI .The claims of the present invention are set forth based on the state of the art defined by the DI patent.
Objeto de la invenciónObject of the invention
Es objeto de la invención un procedimiento para producir una fibra partiendo desde una preforma cilindrica, mediante la: a) Introducción del primero de los extremos de la preforma cilindrica en el interior de una cámara a presión de manera que el eje del cilindro esté alineado con un eje longitudinal; b) Exposición del primer extremo de la preforma a un tratamiento que permita la ductilidad de la preforma en este primer extremo; c) Aplicación de una presión mediante un fluido enfocante, que es introducido en el interior de una cámara a presión por una entrada a tal efecto en dicha cámara; dicho fluido enfocante fluye a lo largo de la prefomia y hacia el primer extremo de dicha preforma, forzando a este primer extremo dúctil de la preforma a través de una tobera de salida de la cámara a presión; en dicha tobera se produce el flujo concéntrico del extremo dúctil de la preforma y el fluido enfocante; dicha tobera se encuentra alineadaThe object of the invention is a process for producing a fiber starting from a cylindrical preform, by means of: a) Introduction of the first of the ends of the cylindrical preform into a pressure chamber so that the axis of the cylinder is aligned with a longitudinal axis; b) Exposure of the first end of the preform to a treatment that allows the ductility of the preform at this first end; c) Application of a pressure by means of a focusing fluid, which is introduced into a pressurized chamber through an entrance to that effect in said chamber; said focusing fluid flows along the predominance and towards the first end of said preform, forcing this first ductile end of the preform through an outlet nozzle of the pressure chamber; in said nozzle the concentric flow of the ductile end of the preform and the focusing fluid occurs; said nozzle is aligned
HOJA DE SUSTITUCIÓN REGLA 26 con el eje de la preforma y está situada aguas abajo en la dirección de flujo del fluido enfocante; dicho fluido enfocante contribuye a expeler una fibra desde el orificio de salida de la cámara a presión, produciéndose una reducción en la dimensión transversal de la fibra con respecto a la dimensión transversal que la preforma tiene en el interior de la cámara a presión;SUBSTITUTE SHEET RULE 26 with the axis of the preform and is located downstream in the flow direction of the focusing fluid; said focusing fluid helps to expel a fiber from the exit orifice of the pressure chamber, resulting in a reduction in the transverse dimension of the fiber with respect to the transverse dimension that the preform has inside the pressure chamber;
Dicho procedimiento se diferencia del expuesto en DI por que la velocidad del fluido enfocante en cada punto de la tobera es inferior a la velocidad de propagación del sonido en el seno del fluido enfocante en ese punto, es decir, se produce en régimen subsónico; y la velocidad del fluido enfocante en cada punto de la tobera es asimismo inferior a 0.25 veces la viscosidad de material de fibra en dicho estado dúctil dividida por la media geométrica de las densidades del material de la fibra y el fluido enfocante, y dividida por el radio final de la fibra que quiere obtenerse; por otra parte, la velocidad del fluido enfocante en cada punto de la tobera debe ser superior a la raíz cuadrada de 2 veces la viscosidad del material de la fibra en dicho estado dúctil, multiplicada por la velocidad de salida de la fibra, dividida por la densidad del gas antes de entrar en la tobera y dividida por la longitud de la tobera.This procedure differs from the one described in DI because the speed of the focusing fluid at each point of the nozzle is lower than the speed of sound propagation within the focusing fluid at that point, that is, it occurs in a subsonic regime; and the speed of the focusing fluid at each point of the nozzle is also less than 0.25 times the viscosity of fiber material in said ductile state divided by the geometric mean of the densities of the fiber material and the focusing fluid, and divided by the final radius of the fiber that you want to obtain; on the other hand, the velocity of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the fiber material in said ductile state, multiplied by the exit velocity of the fiber, divided by the density of the gas before entering the nozzle and divided by the length of the nozzle.
Es asimismo objeto de la presente invención un procedimiento para producir una fibra utilizando un fluido constituyente como proveedor de materia prima para dicha fibra, mediante los siguientes pasos: a) Extrusión de una corriente de dicho fluido constituyente de manera que fluya desde una fuente de alimentación hacia el interior de una cámara a presión en la que se encuentra un fluido enfocante; b) Suministro de fluido enfocante a la cámara a presión de manera que dicho fluido, que se introduce en dicha cámara a través de una apertura de entrada, sale por una tobera de salida de la cámara a presión, encontrándose dicha tobera situada aguas abajo de la corriente de fluido viscoso de fusión; c) el fluido enfocante rodea al chorro de fluido constituyente de manera que dicho chorro abandona la cámara a presión, rodeado del fluido enfocante, por la tobera de salida de la misma; la dimensión transversal de dicho chorro en la salida de dicha tobera es menor que la que tiene en la fuente de alimentación; d) Solidificación de dicho chorro para producir una fibra, que se aleja de la tobera a una determinada velocidad de salida;The object of the present invention is also a process for producing a fiber using a constituent fluid as a supplier of raw material for said fiber, by the following steps: a) Extrusion of a current of said constituent fluid so that it flows from a power source into a pressure chamber in which a focusing fluid is located; b) Supply of focusing fluid to the pressure chamber so that said fluid, which is introduced into said chamber through an inlet opening, exits through an outlet nozzle of the pressure chamber, said nozzle located downstream of the flow of viscous fusion fluid; c) the focusing fluid surrounds the jet of constituent fluid so that said jet leaves the pressurized chamber, surrounded by the focusing fluid, by the nozzle of the same; the transverse dimension of said jet at the outlet of said nozzle is smaller than that of the power supply; d) Solidification of said jet to produce a fiber, which moves away from the nozzle at a certain output speed;
HOJA DE SUSTITUCIÓN REGLA 26 Dicho procedimiento se caracteriza por que la velocidad del fluido enfocante en cada punto de la tobera es inferior a la velocidad de propagación del sonido en el seno del fluido enfocante en ese punto, es decir, se produce en régimen subsónico; y la velocidad del fluido enfocante en cada punto de la tobera es asimismo inferior a 0.25 veces la viscosidad de fluido constituyente dividida por la media geométrica de las densidades del fluido constituyente y el fluido enfocante, y dividida por el radio final de la fibra que quiere obtenerse; por otra parte, la velocidad del fluido enfocante en cada punto de la tobera debe ser superior a la raíz cuadrada de 2 veces la viscosidad del fluido constituyente, multiplicada por la velocidad de salida de la fibra, dividida por la densidad del gas antes de entrar en la tobera y dividida por la longitud de la tobera.SUBSTITUTE SHEET RULE 26 This procedure is characterized in that the speed of the focusing fluid at each point of the nozzle is lower than the speed of sound propagation within the focusing fluid at that point, that is, it occurs in a subsonic regime; and the speed of the focusing fluid at each point of the nozzle is also less than 0.25 times the viscosity of constituent fluid divided by the geometric mean of the densities of the constituent fluid and the focusing fluid, and divided by the final radius of the fiber that you want be obtained; on the other hand, the velocity of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the constituent fluid, multiplied by the speed of exit of the fiber, divided by the density of the gas before entering in the nozzle and divided by the length of the nozzle.
Es asimismo objeto de la invención un procedimiento para producir una fibra como el anterior, caracterizado por que el fluido constituyente es un fluido viscoso obtenido por fusión de otra sustancia sólida.The object of the invention is also a process for producing a fiber like the one above, characterized in that the constituent fluid is a viscous fluid obtained by melting another solid substance.
Por otra parte, es objeto de la invención un procedimiento para producir una fibra según lo anterior, en el que el fluido constituyente está integrado por dos o más componentes en forma de líquidos de los que al menos uno será viscoso, de manera que dichos componentes, que se introducen en dicha cámara a presión a través de una o más aperturas de entrada, están en íntimo contacto en la cámara de presión antes de ser extruidos como un solo fluido viscoso rodeado del fluido enfocante a través de dicha tobera de salida de la cámara a presión, que se encuentra situada aguas abajo de la corriente de dichos componentes en contacto íntimo.On the other hand, a process for producing a fiber according to the above is object of the invention, in which the constituent fluid is composed of two or more components in the form of liquids of which at least one will be viscous, so that said components , which are introduced into said pressure chamber through one or more inlet openings, are in intimate contact in the pressure chamber before being extruded as a single viscous fluid surrounded by the focusing fluid through said outlet nozzle of the pressure chamber, which is located downstream of the flow of said components in intimate contact.
Es también objeto de la invención un dispositivo como el anterior, caracterizado por que los componentes reaccionan químicamente en su flujo a lo largo de la tobera y tras ser expulsados a través de ella en forma de un chorro junto con el fluido enfocante, de manera que finalmente se produce el curado de la mezcla de componentes y la solidificación de la fibra.It is also the object of the invention a device like the previous one, characterized in that the components react chemically in their flow along the nozzle and after being expelled through it in the form of a jet together with the focusing fluid, so that finally the curing of the mixture of components and the solidification of the fiber takes place.
Otro objeto de la invendón es un proceclirniento para producir una fibra en el que el fluido constituyente es una disolución de la materia prima de dicha fibra en un solvente, de manera que la disolución es un fluido viscoso o en fase sol-gel.Another object of the invention is a process for producing a fiber in which the constituent fluid is a solution of the raw material of said fiber in a solvent, so that the solution is a viscous or sol-gel phase fluid.
Es también objeto de la invención un procedimiento para producir una fibra según lo anterior, caracterizado por que dicha disolución pierde total o parcialmente el solvente en su flujo a lo largo de la tobera y tras ser expulsada a través de ella en forma de un chorro junto con el fluido enfocante, de manera que finalmente se produce la solidificación de la fibra.The object of the invention is also a process for producing a fiber according to the above, characterized in that said solution totally or partially loses the solvent in its flow along the nozzle and after being expelled through it in the form of a jet together with the focusing fluid, so that the solidification of the fiber finally occurs.
HOJA DE SUSTITUCI N RE LA 26 Finalmente es objeto de la invención un procedimiento para producir una fibra basado en lo anterior, en el que la concentradón de solvente en dicha disolución es controlada por el fluido enfocante por medio de fenómenos químicos de transferencia de masa.SUBSTITUTE SHEET RE LA 26 Finally, the object of the invention is a process for producing a fiber based on the foregoing, in which the solvent concentrate in said solution is controlled by the focusing fluid by means of chemical mass transfer phenomena.
Descripción de las figurasDescription of the figures
La figura 1 muestra un dispositivo adaptado al procedimiento descrito para producir una fibra utilizando un fluido constituyente como proveedor de materia prima para dicha fibra, mostrándose los siguientes aspectos de la invención: a) fuente de alimentación de fluido constituyente o de la preforma sólida (7) hacia el interior de una cámara a presión (1) en la que se encuentra un fluido enfocante; b) apertura de entrada (2) para la introducción de fluido enfocante; c) tobera de salida (3) de la cámara a presión; d) chorro a la salida de la tobera.Figure 1 shows a device adapted to the described process for producing a fiber using a constituent fluid as a supplier of raw material for said fiber, showing the following aspects of the invention: a) power supply of constituent fluid or solid preform (7 ) into a pressure chamber (1) in which a focusing fluid is located; b) inlet opening (2) for the introduction of focusing fluid; c) outlet nozzle (3) of the pressure chamber; d) jet at the outlet of the nozzle.
HOJA DE SUSTITUCIÓN REGLA 26 SUBSTITUTE SHEET RULE 26

Claims

Reivindicaciones: Claims:
1. Procedimiento para producir una fibra partiendo desde una preforma cilindrica (4), mediante los siguientes pasos: a) Introducdón del primero de los extremos de la preforma cilindrica en el interior de una cámara a presión (1) de manera que el eje del cilindro esté alineado con un eje longitudinal; b) Exposición del primer extremo de la preforma a un tratamiento (6) que permita la ductilidad de la preforma en este primer extremo; c) Aplicación de una presión mediante un fluido enfocante inmiscible con la fase dúctil de la preforma, que es introducido en el interior de una cámara a presión por una entrada (2) a tal efecto en dicha cámara (1); dicho fluido enfocante fluye a lo largo de la preforma y hacia el primer extremo de dicha preforma, forzando a este primer extremo dúctil de la preforma a través de una tobera de salida (3) de la cámara a presión; en dicha tobera se produce el flujo concéntrico del extremo dúctil de la preforma y el fluido enfocante; dicha tobera (3) se encuentra alineada con el eje de la preforma y está situada aguas abajo en la dirección de flujo del fluido enfocante; dicho fluido enfocante contribuye a expeler una fibra desde el orificio de salida de la cámara a presión, produciéndose una reducción en la dimensión transversal de la fibra con respecto a la dimensión transversal que la preforma tiene en el interior de la cámara a presión; caracterizado por que la velocidad del fluido enfocante en cada punto de la tobera es inferior a la veloddad de propagación del sonido en el seno del fluido enfocante en ese punto, es decir, se produce en régimen subsónico; y la velocidad del fluido enfocante en cada punto de la tobera es asimismo inferior a 0.25 veces la viscosidad de material de fibra en dicho estado dúctil dividida por la media geométrica de las densidades del material de la fibra y el fluido enfocante, y dividida por el radio final de la fibra (5) que quiere obtenerse; por otra parte, la veloddad del fluido enfocante en cada punto de la tobera debe ser superior a la raíz cuadrada de 2 veces la viscosidad del material de la fibra en dicho estado dúctil, multiplicada por la velocidad de salida de la fibra, dividida por la densidad del gas antes de entrar en la tobera y dividida por la longitud de la tobera.1. Procedure to produce a fiber starting from a cylindrical preform (4), by the following steps: a) Introduction of the first of the ends of the cylindrical preform into a pressure chamber (1) so that the axis of the cylinder is aligned with a longitudinal axis; b) Exposure of the first end of the preform to a treatment (6) that allows the ductility of the preform at this first end; c) Application of a pressure by means of a focusing fluid immiscible with the ductile phase of the preform, which is introduced into a pressure chamber by an inlet (2) for this purpose in said chamber (1); said focusing fluid flows along the preform and towards the first end of said preform, forcing this first ductile end of the preform through an outlet nozzle (3) of the pressure chamber; in said nozzle the concentric flow of the ductile end of the preform and the focusing fluid occurs; said nozzle (3) is aligned with the axis of the preform and is located downstream in the flow direction of the focusing fluid; said focusing fluid helps to expel a fiber from the exit orifice of the pressure chamber, resulting in a reduction in the transverse dimension of the fiber with respect to the transverse dimension that the preform has inside the pressure chamber; characterized in that the speed of the focusing fluid at each point of the nozzle is lower than the speed of sound propagation within the focusing fluid at that point, that is, it occurs in a subsonic regime; and the speed of the focusing fluid at each point of the nozzle is also less than 0.25 times the viscosity of fiber material in said ductile state divided by the geometric mean of the densities of the fiber material and the focusing fluid, and divided by the final radius of the fiber (5) to be obtained; on the other hand, the velocity of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the fiber material in said ductile state, multiplied by the speed of exit of the fiber, divided by the density of the gas before entering the nozzle and divided by the length of the nozzle.
HOJA DE SUSTITUCIÓN REGLA 26 SUBSTITUTE SHEET RULE 26
2. Proceα_Lmiento para producir una fibra según el procedimiento de la reivindicación 1, caracterizado por que la menor dimensión transversal de la tobera es convergente, aguas abajo en la direcdón del fluido enfocante, y dicha dimensión transversal está entre 1.01 y 100 veces la menor dimensión transversal de la fibra expelida a través de la tobera convergente.2. Proceed to produce a fiber according to the method of claim 1, characterized in that the smallest transverse dimension of the nozzle is convergent, downstream in the direction of the focusing fluid, and said transverse dimension is between 1.01 and 100 times the smallest dimension cross section of the expelled fiber through the convergent nozzle.
3. Proceα_ αiento para producir una fibra según las reivindicaciones 1 y 2, caracterizado por que el tratamiento que permite la ductilidad involucra el calentamiento de la preforma.3. Proceed to produce a fiber according to claims 1 and 2, characterized in that the treatment that allows ductility involves heating the preform.
4. Procedimiento para producir una fibra según las reivindicaciones 1, 2 y 3, caracterizado por que la preforma es calentada a través del fluido enfocante.4. Process for producing a fiber according to claims 1, 2 and 3, characterized in that the preform is heated through the focusing fluid.
5. Procedimiento para producir una fibra según las reivindicadones 1 y 2, caracterizado por que el fluido enfocante es un gas.5. Process for producing a fiber according to claims 1 and 2, characterized in that the focusing fluid is a gas.
6. Procedimiento para producir una fibra según la reivindicación 5, caracterizado por que el gas es un gas inerte que ha sido calentado.Method for producing a fiber according to claim 5, characterized in that the gas is an inert gas that has been heated.
7. Procedimiento para producir una fibra según la reivindicación 6, caracterizado por que el gas sale a través de la salida de la cámara a presión a una velocidad subsónica.7. Method for producing a fiber according to claim 6, characterized in that the gas exits through the outlet of the pressure chamber at a subsonic speed.
8. Procedimiento para producir una fibra según la reivindicación 1, caracterizado por que la preforma dúctil sale a través de una tobera, la cual comienza como una apertura en el interior de la cámara a presión y se extiende a lo largo de una línea sensiblemente perpendicular a la superficie interna de la cámara a presión, hasta la apertura de salida de dicha cámara.Method for producing a fiber according to claim 1, characterized in that the ductile preform exits through a nozzle, which begins as an opening inside the pressure chamber and extends along a substantially perpendicular line to the inner surface of the pressure chamber, until the outlet opening of said chamber.
9. Procedimiento para producir una fibra según las reivindicadones 1 a 8, caracterizado por que la presión P0 a que se somete el fluido enfocante en la cámara de presión cumple las restricciones9. Process for producing a fiber according to claims 1 to 8, characterized in that the pressure P 0 to which the focusing fluid in the pressure chamber is subjected meets the restrictions
Figure imgf000014_0001
Figure imgf000014_0001
HOJA DE SUSTITUCIÓN REGLA 26 donde μ¡ es la viscosidad de la preforma dúctil en su primer extremo, N , es la velocidad de la fibra en la tobera, L es la longitud de la tobera, a es el radio de la fibra, Pa es la presión ambiente a la salida de la cámara a presión y Re=p, N a/μ, es el número de Reynolds que caracteriza al flujo de la fibra.SUBSTITUTE SHEET RULE 26 where μ¡ is the viscosity of the ductile preform at its first end, N, is the speed of the fiber in the nozzle, L is the length of the nozzle, a is the radius of the fiber, P a is the ambient pressure a The output of the pressure chamber and Re = p, N a / μ, is the Reynolds number that characterizes the fiber flow.
10. Procedimiento para producir una fibra utilizando un fluido constituyente como proveedor de materia prima para dicha fibra, mediante los siguientes pasos: i. Extrusión de una corriente de dicho fluido constituyente de manera que fluya desde una fuente de alimentación (7) hada el interior de xana cámara a presión (1) en la que se encuentra un fluido enfocante; ii. Suministro a dicha cámara de un fluido enfocante, inmiscible con dicho fluido constituyente, de manera que dicho fluido, que se introduce en dicha cámara a través de una apertura de entrada (2), sale por una tobera de salida (3) de la cámara a presión, encontrándose dicha tobera situada aguas abajo de la corriente de fluido constituyente; iii. El fluido enfocante rodea al chorro de fluido constituyente de manera que dicho chorro abandona la cámara a presión, rodeado del fluido enfocante, por la tobera de salida de la misma; la dimensión transversal de dicho chorro en la salida de dicha tobera (5) es menor que la que tiene en la fuente de alimentación; iv. Solidificación de dicho chorro para producir una fibra, que se aleja de la tobera a una determinada velocidad de salida; caracterizado por que la velocidad del fluido enfocante en cada punto de la tobera es inferior a la velocidad de propagación del sonido en el seno del fluido enfocante en ese punto, es decir, se produce en régimen subsónico; y la velocidad del fluido enfocante en cada punto de la tobera es asimismo inferior a 0.25 veces la viscosidad de fluido constituyente dividida por la media geométrica de las densidades del fluido constituyente γ el fluido enfocante, y dividida por el radio final de la fibra que quiere obtenerse; por otra parte, la velocidad del fluido enfocante en cada punto de la tobera debe ser superior a la raíz cuadrada de 2 veces la viscosidad del fluido constituyente, multiplicada por la veloddad de salida de la fibra, dividida por la densidad del gas antes de entrar en la tobera y dividida por la longitud de la tobera.10. Procedure to produce a fiber using a constituent fluid as a supplier of raw material for said fiber, through the following steps: i. Extrusion of a stream of said constituent fluid so that it flows from a power source (7) into the interior of a pressure chamber (1) in which a focusing fluid is located; ii. Supplying to said chamber a focusing fluid, immiscible with said constituent fluid, so that said fluid, which is introduced into said chamber through an inlet opening (2), exits through an outlet nozzle (3) of the chamber under pressure, said nozzle located downstream of the constituent fluid stream; iii. The focusing fluid surrounds the jet of constituent fluid so that said jet leaves the pressurized chamber, surrounded by the focusing fluid, by the outlet nozzle thereof; the transverse dimension of said jet at the outlet of said nozzle (5) is smaller than that of the power supply; iv. Solidification of said jet to produce a fiber, which moves away from the nozzle at a certain output speed; characterized in that the speed of the focusing fluid at each point of the nozzle is lower than the speed of sound propagation within the focusing fluid at that point, that is, it occurs in a subsonic regime; and the velocity of the focusing fluid at each point of the nozzle is also less than 0.25 times the viscosity of constituent fluid divided by the geometric mean of the densities of the constituent fluid γ the focusing fluid, and divided by the final radius of the fiber you want be obtained; on the other hand, the speed of the focusing fluid at each point of the nozzle must be greater than the square root of 2 times the viscosity of the constituent fluid, multiplied by the speed of exit of the fiber, divided by the density of the gas before entering in the nozzle and divided by the length of the nozzle.
HOJA DE SUSTITUCIÓN REGLA 26 SUBSTITUTE SHEET RULE 26
11. Procedimiento para producir una fibra según el procedimiento de la reivindicación 10, caracterizado por que la menor dimensión transversal de la tobera es convergente, aguas abajo en la dirección del fluido enfocante, y dicha dimensión transversal está entre 1.01 y 100 veces la menor dimensión transversal de la fibra expelida a través de la tobera convergente.11. Method for producing a fiber according to the method of claim 10, characterized in that the smallest transverse dimension of the nozzle is convergent, downstream in the direction of the focusing fluid, and said transverse dimension is between 1.01 and 100 times the smallest dimension cross section of the expelled fiber through the convergent nozzle.
12. Proceclimiento para producir una fibra según la reivindicación 10, caracterizado por que la temperatura del el fluido constituyente es controlada por el fluido enfocante mediante fenómenos de transferencia de energía.12. Procedure for producing a fiber according to claim 10, characterized in that the temperature of the constituent fluid is controlled by the focusing fluid by means of energy transfer phenomena.
13. Proceα-imiento para producir una fibra según la reivindicación 10, caracterizado por que el fluido enfocante es un gas.13. The process for producing a fiber according to claim 10, characterized in that the focusing fluid is a gas.
14. Procedimiento para producir una fibra según la reivindicación 13, caracterizado por que el gas es un gas inerte que ha sido calentado.14. Method for producing a fiber according to claim 13, characterized in that the gas is an inert gas that has been heated.
15. Procedimiento para producir una fibra según la reivindicación 10, caracterizado por que el fluido constituyente sale a través de una tobera, la cual comienza como una apertura en el interior de la cámara a presión y se extiende a lo largo de una línea sensiblemente perpendicular a la superficie interna de la cámara a presión, hasta la apertura de salida de dicha cámara.15. Method for producing a fiber according to claim 10, characterized in that the constituent fluid exits through a nozzle, which begins as an opening inside the pressure chamber and extends along a substantially perpendicular line to the inner surface of the pressure chamber, until the outlet opening of said chamber.
16. Procedimiento para producir una fibra según las reivindicaciones 10 a 15, caracterizado por que la presión P0 a que se somete el fluido enfocante en la cámara de presión cumple las restricciones16. Process for producing a fiber according to claims 10 to 15, characterized in that the pressure P 0 to which the focusing fluid in the pressure chamber is subjected meets the restrictions
Figure imgf000016_0001
donde μ, es la viscosidad del fluido constituyente, N , es la velocidad de la fibra en la tobera, L es la longitud de la tobera, a es el radio de la fibra, Pa es la presión ambiente a la salida de la cámara a presión y Re=P[ V, a./μ¡ es el número de Reynolds que caracteriza el flujo de la fibra.
Figure imgf000016_0001
where μ, is the viscosity of the constituent fluid, N, is the speed of the fiber in the nozzle, L is the length of the nozzle, a is the radius of the fiber, P a is the ambient pressure at the outlet of the chamber at pressure and Re = P [ V, a./μ¡ is the Reynolds number that characterizes the fiber flow.
HOJA DE SUSTITUCIÓN REGLA 26 SUBSTITUTE SHEET RULE 26
17. Procedimiento para producir una fibra según las rdvindicaciones 10 a 16, caracterizado por que el fluido constituyente es un fluido viscoso obtenido por fusión de otra sustancia sólida17. Process for producing a fiber according to claims 10 to 16, characterized in that the constituent fluid is a viscous fluid obtained by melting another solid substance
18. Procedimiento para producir una fibra según las reivindicaciones 10 a 16, caracterizado por que el fluido constituyente está integrado por dos o más componentes en forma de líquidos de los que al menos uno será viscoso, de manera que dichos componentes, que se introducen en dicha cámara a presión a través de una o más aperturas de entrada, están en íntimo contacto en la cámara de presión antes de ser extruidos como un solo fluido viscoso rodeado del fluido enfocante a través de dicb-a tobera de salida de la cámara a presión, que se encuentra situada aguas abajo de la corriente de dichos componentes en contacto íntimo.18. Method for producing a fiber according to claims 10 to 16, characterized in that the constituent fluid is composed of two or more components in the form of liquids of which at least one will be viscous, such that said components, which are introduced into said pressure chamber through one or more inlet openings, are in intimate contact in the pressure chamber before being extruded as a single viscous fluid surrounded by the focusing fluid through dicb-a nozzle of the pressure chamber , which is located downstream of the current of said components in intimate contact.
19. Procedimiento para producir una fibra según el procedimiento de la reivindicación 18, caracterizado por que los componentes reaccionan quí nicamente en su flujo a lo largo de la tobera y tras ser expulsados a través de ella en forma de un chorro junto con el fluido enfocante, de manera que finalmente se produce el curado de la mezcla de componentes y la solidificadón de la fibra.19. Method for producing a fiber according to the method of claim 18, characterized in that the components react chemically in their flow along the nozzle and after being expelled through it in the form of a jet together with the focusing fluid , so that finally the curing of the mixture of components and the solidification of the fiber takes place.
20. Procedimiento para producir una fibra según las reivindicaciones 10 a 16, caracterizado por que el fluido constituyente es una disolución de la materia prima de dicha fibra en un solvente, de manera que la disolución es un fluido viscoso o en fase sol-gel.20. Process for producing a fiber according to claims 10 to 16, characterized in that the constituent fluid is a solution of the raw material of said fiber in a solvent, so that the solution is a viscous or sol-gel phase fluid.
21. Procedimiento para producir una fibra según el procedimiento de la reivindicación 20, caracterizado por que dicha disolución pierde total o parcialmente el solvente en su flujo a lo largo de la tobera y tras ser expulsada a través de ella en forma de un chorro junto con el fluido enfocante, de manera que finalmente se produce la solidificación de la fibra.21. Process for producing a fiber according to the method of claim 20, characterized in that said solution totally or partially loses the solvent in its flow along the nozzle and after being expelled therethrough in the form of a jet together with the focusing fluid, so that the solidification of the fiber finally occurs.
22. Procedimiento para producir una fibra según la reivindicación 21, caracterizado por que la concentración de solvente en dicha disolución es controlada por el fluido enfocante por medio de fenómenos químicos de transferencia de masa. 22. Process for producing a fiber according to claim 21, characterized in that the concentration of solvent in said solution is controlled by the focusing fluid by means of chemical mass transfer phenomena.
PCT/ES2005/000117 2004-03-09 2005-03-07 Method for the production of fibres by means of extrusion with a focusing gas in subsonic regime WO2005087673A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10369579B1 (en) 2018-09-04 2019-08-06 Zyxogen, Llc Multi-orifice nozzle for droplet atomization

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2197310A (en) * 1986-07-28 1988-05-18 Mitsubishi Cable Ind Ltd Clad optical fibres prepared from silica sol
US6116516A (en) * 1996-05-13 2000-09-12 Universidad De Sevilla Stabilized capillary microjet and devices and methods for producing same
WO2001069289A2 (en) * 2000-03-10 2001-09-20 Flow Focusing, Inc. Methods for producing optical fiber by focusing high viscosity liquid

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2197310A (en) * 1986-07-28 1988-05-18 Mitsubishi Cable Ind Ltd Clad optical fibres prepared from silica sol
US6116516A (en) * 1996-05-13 2000-09-12 Universidad De Sevilla Stabilized capillary microjet and devices and methods for producing same
WO2001069289A2 (en) * 2000-03-10 2001-09-20 Flow Focusing, Inc. Methods for producing optical fiber by focusing high viscosity liquid

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GAÑAN-CALVO A. ET AL.: "Steady high viscosity liquid microjet production and fiber spinning using co-flowing gas conformation.", EUROPEAN PHYSICAL JOURNAL B., vol. 39, no. 1, March 2004 (2004-03-01), pages 131 - 137 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10369579B1 (en) 2018-09-04 2019-08-06 Zyxogen, Llc Multi-orifice nozzle for droplet atomization

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