CZ20001727A3 - Process and apparatus for continuous spinning and collecting fibers - Google Patents

Abstract

The spinning device (10) consists of a spinneret (20), a vapor recovery device (30) and a tensioning device (40) or other suitable means of maintenance spun fibers in a stretched state. Extraction device (30) It is particularly advantageous when the fiber-forming substance is present it contains volatile components such as unreacted monomer or the solvent component of the solvated resin. Tensioning the device (40) can be simply formed by a coil or a spool that tensions the continuously spun fibers. At The method utilizes means for maintaining sufficient the tension of the continuously spun fibers to be they are prevented from being released after the fibers have been formed and during their collection. Constant voltage applied allows the continuous fibers to be aligned into a linear fiber grouping.

Description

Technical field

The invention relates to a method and apparatus for forming a continuous, unidirectional bundle of small-strength, high-strength, carbon-based carbon fibers based on resin.

In general, the present invention relates to a blow-spinning process in which. it is formed by a blown spinning product having the characteristics of melting the spun product at blown spinning speeds. Thus, the present invention contributes to improving the uniformity of the article and to reducing manufacturing costs.

Although the present invention is particularly useful in the blowing spinning of carbon resin fibers, other possible applications will be apparent from the following description. »·

BACKGROUND OF THE INVENTION

Since the prior art blow molding processes are well known and generally known, they will be described in the following only from a very general perspective.

A typical way. blow spinning utilizes spun _l substance attenuator media, usually a gas, and even spinning die which comprises forming capillaries ¹

I fibers. During the spinning process, the fibers emerge from the capillaries and are contacted with a attenuating medium that draws or stretches each fiber while increasing its length and decreasing its diameter. Since the attenuating medium is typically a gas, the cooling rate of the fibers is also affected.

The fibers produced by the blown spinning process are typically short non-continuous fibers having a length of less than two inches. In contrast, melt spun fibers are generally continuous fibers ⁵ having a substantially infinite length. The length of the fibers in the melt-spun fibers is usually chosen by construction so that it is not given. by the method of producing fibers. In addition, meltblown fibers have better uniformity than blownblown fibers.

Several types of dies can be used for blowing fiber spinning. In general, blow molding dies are determined by the direction of attenuation. gas contact with the fibers. Two common designs are annular dies and slot dies.

In an annular die, the attenuating gas typically exits from a ring formed around each capillary and flows in a direction parallel to the fiber. The attenuation occurs due to the pulling action of the gas on the fiber.

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In a slot die, the attenuator gas then exits the slots on each side of the die tip and comes into contact with the fiber at an angle. The contact angle, which is determined by the die geometry, is optimized for a particular spun fabric to achieve the desired characteristics of the resulting fiber.

The present invention is equally applicable to all types of blow molding dies.

Typical blow-spinning methods allow the spun fibers to fall onto the collection surface after the fibers have been weakened. Depending on the fiber composition, a two-dimensional or three-dimensional web is formed from short and randomly arranged fibers in this way. The fibers collected in this manner may be undesirably bent or kinked, resulting in lower tensile strength of the respective fiber. The underlying cause of fiber bending and kinking is considered to be the turbulence generated by the attenuation gas during fiber cooling.

Those skilled in the art are well aware that the fiber collection process is a critical step in achieving high tensile strength of the fibers produced. Methods of collecting blown-spun fibers known from the prior art; of the prior art, usually increase the number of bends and kinks of the fibers by collecting the fibers in a three-dimensional random web.

U.S. Pat. No. 5,648,041 describes the collection of fibers in a two-dimensional web. However, 9 ··· * · ·············

Even means for achieving a two-dimensional web require the use of additional processing equipment and also accurate!

attenuation gas control ..

As demonstrated in melt spinning methods, manufacturers have long established that DC fiber removal or collection, for example, on a bobbin or winder, will result in obtaining the most favorable fiber properties. However, prior to the development of the present invention, means have not been discovered to accomplish this object in a blown fiber spinning process.

SUMMARY OF THE INVENTION. '.

The present invention overcomes the drawbacks previously encountered in blown-spun fibers. by developing an apparatus and method for collecting or collecting even by continuous blowing the spun fibers. In addition, the method and apparatus of the present invention provide DC withdrawal or collection of continuous fibers.

As used herein, the term "continuous fibers" means fibers of substantially infinite length. The interruption of the length of the continuous fibers generally occurs either intentionally or due to some manufacturing problem.

The fibers produced in accordance with the present invention further have improved fiber uniformity and improved tensile strength. Finally, the present invention provides such a method of blow-spinning by means of which a

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It is possible to produce a product provided by fusion spinning at a speed that corresponds to the blowing spinning.

The object of the present invention provides an apparatus for blowing spinning continuous, infinitely long fibers. The new device comprises a die to blow spinning, provided with at least one capillary for forming filaments, and means for nasměrovávání attenuator gas into contact with the fibers which leave the capillaries ^1.

The present apparatus also provides means for applying stress in the fiber before the fiber is cured or cooled, that is, than; the subject fiber solidifies. Further, the present invention provides for the removal of gases and vapors from the fiber bundle prior to collection of these fibers on the collecting device.

Further, in accordance with the present invention, a method for producing continuous blown spun fibers has been developed. This method of producing fibers according to the invention provides for the production of fibers by heating the spunbond fabric and forming the fibers by passing the fabric through a blow molding die. The fibers are attenuated by the attenuator gas.

Once the respective attenuation has been carried out, the method prevents the formation of deflection of the fibers by maintaining the tension in the fibers by means of a tensioning device. The continuous filaments produced by the blowing spinning may be collected on a tensioning device or on a subsequent device such as a bobbin or a winder.

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In accordance with the present invention, a method for producing direct blown carbon fiber spun fibers has been further developed. This new method utilizes means for maintaining tension in the fibers to prevent their deflection before curing or cooling _; fibers.

The present invention further comprises the step of collecting said fibers in the form of a warp belt or crossed; continuous filament yarns on the collecting device. '

If necessary levers. the present invention also provides for the removal of gases and vapors from the fibers before collecting the fibers on the collecting device. The gases and vapors are preferably removed by means of a transverse aeration applied to the fibers before they reach the collecting device. !

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Finally, the process of the present invention will also be useful in spinning fibers from materials such as carbon resins, polyamides including nylons, and polyesters such as; Dacron®, polypropylenes, polyurethanes such as Lycra®, polyaramides such as Kevlar®, and liquid crystalline materials such as

for example mesophase resin, dissolved mesophase; resin and "Zenite ®", all of the foregoing being trademarks of E.I. du Pont de Nemours and Company. Use of method i

Of course, according to the invention, it is not limited to the above-mentioned substances. '• · · ···

In addition, when spinning resin-based fibers, the present invention provides continuous straight and blown fibers. These fibers have no kinks, no bends or any other collecting defects or defects, which usually occur during blow-spinning, and which reduce the mechanical properties of the fibers. Accordingly, the present invention provides fibers having; significantly higher tensile strength. ~ ¹

They have further been developed in accordance with the present invention; cross-woven continuous filament yarn, warp belt and ¹ DC fiber sliver fabric, which are made of continuous filaments produced by a blow-spinning process. ¹

BRIEF DESCRIPTION OF THE DRAWINGS ¹

The invention will be explained in more detail below with reference to an exemplary embodiment thereof, the description of which will be described below. is given with reference to a single drawing of the drawing, in which a general view of a device according to the invention is shown.

DETAILED DESCRIPTION OF THE INVENTION

A. Blow spinning and fiber removal equipment

As shown in a single drawing of the drawing, the present invention relates to an apparatus for blowing and removing fibers. This apparatus 10 is provided with a conventional blow-molding die, generally designated 20, a vapor removal device 30, and

The tensioning device 40 or other suitable means for maintaining the tension of the spun fibers.

Blow molding dies are well known in the art. As already mentioned above, there are in fact several well known variations of blow molding dies. The present invention can advantageously be used for all types of blowing dies.

For further information on the function of the blow molding dies, the following references are incorporated herein by reference:

&Quot; Vibration and Stability in Melt Blowing Process, Industrial and Engineering Chemistry, 1993, 32, 3100-3111, Rao and Shambaugh;

A Macroscopic View of the Melt Blowing Process for Producing Microfibers, Industrial and Engineering Chemistry, 1988, 27, 2363-2372, Shambaugh;

"Three-Dimensional Temperature Field of Rectangular Array of Practical Air Jets, Industrial and Engineering Chemistry, 1994, 33, 730-735, Mohammed and Shambaugh;

“Superfine Thermoplastic Fibers, Van. A. Wente, Industrial and Engineering Chemistry, Vol. 48, No. 8, August 1956, pages 1342-1346;

U.S. Patent 4,847,125;

U.S. Pat. No. 4,380,570; and U.S. Pat. No. 5,286,182.

The optional vapor removal device 30 of the present invention is particularly useful when the spinning substance comprises volatile components such as unreacted monomers or soluble components of the dissolved resins.

Dissolved resins were developed by the owner of this;

of the invention and are described, for example, in U.S. Pat. No. 5,259,947, U.S. Pat. No. 5,437,780, U.S. Pat. No. 5,501,788 or U.S. Pat. No. 5,538,621, which are incorporated herein by reference.

In a preferred embodiment, the vapor removal device 30 is disposed between the die 20 and the tensioning device 40. The preferred vapor removal device 30 utilizes one or more blowers or fans, not shown, or other means for generating cross-flow or gas movement. or air. Cross-flow ventilation effectively removes hydrocarbon vapors or other entrained components from the fiber bundle, contributing to the entrapment of the fibers' emerging from the bundle. Removing volatile components from the fiber assembly or bundle prior to collection and collection contributes to improving the processability of the fibers.

Finally, the device according to the invention comprises a tensioning device 40. As shown, the tensioning device 40 may also be formed, very simply, for example, in the form of a single coil or spindle, which applies stress to the continuous blown fibers. '

Alternatively, additional coils, cylinders, pins or hot chambers and the like may be provided upstream or downstream of the tensioning device 40 to perform pull-pull functions. cold and hot setting. ,, 'í

The precise arrangement or devices used are not essential to the present invention. Rather, the primary task is to provide means for maintaining sufficient tension by continuously blowing the spun fibers to prevent their deflection which might follow after the fibers have been formed and during the removal or collection process. The constant stress allows alignment of the continuous filaments into a straight bundle which can be collected and removed by any method known to those skilled in the art, such as a warp belt or transverse continuous drawing of the filaments into the shape of a tow yarn.

B. Continuous Blow Molding Method i

Referring to the accompanying drawing of the drawing, in accordance with the present invention, a method for collecting and removing blown spunbond fibers has been developed. As is known in the art, a warp belt, a continuous filament tow or other products can be formed by various removal methods.

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As mentioned above, the method of spinning fibers by blow molding is generally and well known. However, although the advantages of collecting spunbonded fibers in the DC fashion were known, they could not be achieved prior to the present invention.

In accordance with the method of the present invention, spunbond fibers are formed by passing a fabric capable of spinning through the capillaries of a blow molding die. When the spun fibers exit from these capillaries, they are contacted with the attenuator gas. These materials are preferably removed prior to collection. fibers. This is particularly advantageous when the fibers are made from dissolved resins, as the presence of any entrapped hydrocarbons may impair the quality of the resulting product.

The vapor removal process is preferably carried out by generating a cross-flow suction. This transverse suction is preferably performed after the fibers have been weakened, but before the fibers have been collected. This crosswise _flow: suction may be generated by one or more fans, blowers, compressors, or other suitable devices which are not shown in the drawings.

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The vapor removal method is not to be confused with the conventional rapid cooling step, by means of a transverse flow, which is typically used in melt spinning fibers. The dissolved resin fibers are rapidly cooled and heat cured near the die in an area where the rapidly expanding and cooling weakening gas predominates. Thus, the dissolved resin fibers always terminate the rapid cooling process prior to vapor removal. ί '

Once the fibers have been formed, the present invention utilizes a tensioning device 40 to maintain a constant and uniform force on the fibers. The stress applied to the fibers prevents the fibers from bending and eventually kinking, while allowing the collection and collection of continuous and infinitely long fibers formed by the blow-spinning process.

In addition, applying a constant stress after the formation of the fibers allows the alignment of the fibers to a rectilinear bundle, which may be. harvested and collected on the reel as a warp belt or as a continuous filament yarn. The impact of the additional stress on the fiber attenuation will vary depending on the spinning properties of the material. However, the additional voltage does not act as the main attenuation force, since this function is rather performed by the attenuator gas.

Once the continuous filaments are aligned on the spool or other suitable gathering device, the filaments may be cut for further processing. The method of sensing the fibers from the coil will determine the characteristic properties of the coil: ftftftft: ftftftft ftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftftft ftft final product. If a single cut is made along the entire length of the bobbin, the fibers may be removed in the form of a balanced DC fibrous strand fabric, the length of which will be the same as the circumference of the bobbin.

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If straight and equally long fibers are desired, the fibers may be slipped off the spool at certain intervals to achieve the desired fiber length.

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Alternatively, as is well known to those skilled in the art, the fibers may be processed on a bobbin, even may be cut to the desired length after removal or;

extractions, after which they can be drawn, wound or ^processed:!

any other desired way. Additionally, to be "rolls, pins, hot chamber nebojjiná very well known devices arranged upstream or downstream from where the continuous filaments j compensated by the tensioning device 40 in order to ensure the function of fiber drawing cold or ^_heat:: their heat setting. ;

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C. Continuous Blown Spun Carbon Fibers ”i

The present invention ⁸ is particularly useful for spinning continuous fibers of mesophase resin and dissolved resins.

U.S. Pat. No. 5,648,041 discloses difficulties in producing straight fibers from dissolved resin, and in particular from dissolved mesophase resin. As mentioned herein, the rapid cooling of the fibers in the region of turbulence produced by the attenuating gas leads to kinking and bending of the fibers.

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However, by using the tensioning device 40 of the present invention, continuous and blown spun fibers are achieved. In addition, the present invention increases the potential for a smaller final diameter of articles by providing fibers with a higher power transmission of single fiber and composite fibers. Finally, the present invention may allow them to be; the diameters of the capillaries of the spinning die are greater, thereby eliminating the problems caused by small capillaries, such as clogging.

Table 1 shows that the fibers of the present invention have improved tensile strength and reduced spun variation ^; I average compared to fibers made by methods that are! known in the art. The following test results were obtained with fibers spun from a single batch of dissolved mesophase resin using the same blow molding die.

As shown in Table 1, the fabrics of the present invention that were collected on a reel had a higher tensile strength and a smaller percentage coefficient of spun diameter than the fibers collected in the form of a web. The percent fluctuation coefficient (% CV) of the fiber diameter is ^! the standard deviation, divided by the major fiber diameter, and expressed as a percentage. Less% CV means improvement ^! fiber homogeneity.

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Table 1 Coefficient fluctuations Way gathering Characteristics fibers Strength in turn (Kpsi) Spinned diameter (% CV) Fleece Knot ¹ 285 t — 1 KO Fleece Knotted 278 11.2 Coil Direct ' 378 3,9, Coil Direct 420 5.8

Other possible embodiments of the invention will be apparent to those skilled in the art on the basis of this.

of this disclosure, or of practicing the subject matter described herein. The foregoing description is considered to be exemplary only, and the true scope and spirit of the invention are set forth in the following claims.

Claims (19)

PATENT CLAIMS CLAIMS 1. A continuous fiber blowing machine comprising: die to blow spinning, provided with at least ^one capillary for forming one fiber attenuator means for directing gas onto said fiber as it exits said capillary, - mechanical means for maintaining tension in said fiber following the attenuation of said fiber, said mechanical means selected from the group comprising coils, rollers and winders or any combination thereof. • l 2. The apparatus of claim 1, further comprising: means for removing gases and vapors from said fiber after attenuating said fiber. ί AND The apparatus of claim 1, wherein said means for maintaining tension in said fiber also provides means for collecting said fiber. 4. A method for producing continuous blown, spunbonded mesophase resin fibers: Φ, ΦΦ β Φ Φ 5 Φ Φ Φ 4 Φ Φ Φ φ Φ Φ Φ • • • Způsob φ »» »» »» »» »» »» »» »» »» »» »» »» » passing said mesophase resin through capillaries located in a blow molding die to form said mesophase resin into the fibers, attenuating said fibers by contacting said fibers with a attenuating gas, after attenuating maintaining sufficient stress in said fibers to prevent deflection formation ii by collecting said fibers at the collecting tract. 5. A method as claimed in claim 1 4 that said fibers are collected on a collection device, 6. The method of claim 1, either collecting continuous filament yarns as a warp band. of claim 4, wherein said fibers are or are cross-linked The method of claim 6, wherein said warp belt or crossed continuous filament yarn is further processed into a DC fiber sliver fabric. 8. The method of claim 4 wherein gases and vapors are removed from said fibers prior to collecting said fibers on said collecting means. 9. The method of claim 4, wherein said gases and vapors are removed by means of a transversely flowing vent applied to the fibers through the collecting device. 10. A method of making continuous blown spunbonded filaments, including heating the spunbond to a temperature sufficient to flow, followed by forming continuous filaments by passing the spunbond and capillaries therein and attenuating said spunbonds. the fibers after their exit from the capillaries through the contacting of said fibers fibers with at least one current  gas, characterized contains: with that this way - Mon attenuation said fibers maintenance Tension in said fibers, by means of a tensioning device. The method of claim 10, further comprising the step of collecting said fibers as a warp belt or as a cross-linked continuous filament yarn on a winding device configured to receive said fibers from said tensioning device. • 4 94 t according to claim 11, comprising the step of vapors before collecting said 12. A method of removing gases and fibers. 13. The method of said fibers is flowing ventilation. according to claim 11, characterized in that it is applied transversely to said fibers prior to collection 14. Crosswise characterized in that the fibrous yarn comprises continuous fibers produced by a blow-spinning process. 15. The cross-linked filament yarn of claim 14, wherein the fibers are spun from resin material, polyamides, wherein said fibers are selected from the group consisting of carbon nylons, polyesters, polypropylenes, polyurethanes, polyaramides, and liquid crystalline materials. A warp belt, characterized in that it comprises continuous fibers produced by a blow-spinning process. 17. The apparatus of claim 16, wherein said continuous filaments are collected by means for generating stress in said filaments, said means being selected from the group comprising coils, rollers and winders. Ť and. 2-0 18. DC characterized by continuous filaments, spinning. fiber made by strand. fabric ¹ is made by a blow molding method 19. The apparatus of claim 18, wherein said DC fiber web is collected by means for generating tension in said web, said means being selected from the group consisting of coils, rollers and winders.