JP5065704B2 - Method for producing twisted yarn - Google Patents

Description

  The present invention relates to a method for producing twisted yarn. More specifically, it is composed of a plurality of filaments having a small fiber diameter, and since the liquid contained in the fiber bundle is small, it is easy to wind up, and it is possible to efficiently obtain a twisted yarn without the need for a separate twisting step. The present invention relates to a method for producing a twisted yarn.

In the field of regenerative medicine, a fiber structure may be used as a base material when cells are cultured. And as a fiber structure, the structure which consists of the fiber which used the polyglycolic acid used for the surgical suture etc. as a raw material, for example is examined (refer nonpatent literature 1).
However, the fiber structure using fibers obtained by a normal method as described in Non-Patent Document 1 has a small effective area to which cells can adhere because the fiber diameter is too large. . Therefore, in order to increase the surface area for culturing, a fiber structure having a smaller fiber diameter has been desired.

  Here, as a method for producing a fiber structure having a small fiber diameter, an electrostatic spinning method is already known (see Patent Documents 1 and 2). The electrostatic spinning method is a method of forming a fiber structure by introducing a liquid, for example, a solution containing a fiber-forming substance into an electric field and causing the liquid to flow toward an electrode. Usually, the fiber-forming substance is cooled (e.g., when the spinning liquid is solid at room temperature), chemically cured (treatment with curing steam, etc.), solvent evaporation, etc. To solidify and form fibers. The obtained fiber is collected on an appropriately arranged electrode to form a fiber structure, and is peeled off from the electrode if necessary.

  In addition, it is already known that a fiber structure obtained by an electrospinning method is used as a substrate for culturing cells (see Non-Patent Document 2). In Non-patent Document 2, smooth muscle cells are cultured on a fiber structure made of polylactic acid formed by an electrospinning method, and the regeneration of blood vessels is studied.

  However, when producing a fiber structure by an electrospinning method, an electrode for collecting the fibers is required, so that many of the obtained fiber structures are planar, and therefore can be produced. The body shape was limited. On the other hand, there are tissues of various structures in the living body, and the presence rate of cells as linear bodies is particularly large. Therefore, there has been a great demand for fibers having a small fiber diameter obtained by an electrospinning method and capable of forming a form other than a planar body.

  In response to this requirement, Patent Documents 3 and 4 propose a method for producing a fiber composed of a filament having a small average fiber diameter produced by an electrostatic spinning method. According to the fibers described in Patent Documents 3 and 4, it is possible to create a structure other than a planar body by processing such as knitting as well as using it as a suture.

JP-A 63-145465 JP 2002-249966 A Japanese Patent Laying-Open No. 2005-226210 JP-T-2006-507428 Noriya Ohno, Director of Translation by Masao Aizawa, “Regenerative Medicine”, NTS Corporation, January 31, 2002, p. 258 Joel D. Stitzel, Kristin J. Pawlowski, Gary E. Wnek, David G. Simpson, Gary L. Bowlin, “Journal of Biomaterials Applications” ), SAGE Publications, 2001, 16, pages 22-33.

  However, in the method described in Patent Document 3, when the strength of the fiber assembly is a very low polymer, or when a highly adhesive polymer is used, the fiber assembly is removed from the fiber assembly collecting device. Since the fiber assembly is broken when it is pulled up, it is impossible to continuously produce a twisted yarn.

  Further, the fiber obtained by the method described in Patent Document 4 contains a large amount of the solution used in the coagulation bath in the fiber bundle, and thus there is a problem that winding cannot be performed sufficiently. there were. Furthermore, since it is necessary to separately provide a fiber twisting process, it has been difficult to reduce production costs.

  The present invention has been made in view of the above problems, and the object thereof is constituted by a plurality of filaments having a small fiber diameter, and since the liquid contained in the fiber bundle is small, winding is easy. In addition, an object of the present invention is to provide a method for producing a twisted yarn that can efficiently obtain a twisted yarn without the need for a separate twisting step.

  The present inventors have made extensive studies in view of the above problems. As a result, a fiber assembly is created by electrostatic spinning using the liquid surface of the liquid tank containing the liquid as a collection surface, and the fiber bundle is drawn from the fiber assembly and then twisted while the fiber bundle is running. As a result, it has been found that the above problems can be solved, and the present invention has been completed.

That is, the present invention provides a fiber-forming composition preparation step for preparing a fiber-forming composition containing a fiber-forming substance and a solvent, and a fiber is ejected by applying a high voltage to the fiber-forming composition. A spinning step to form, an accumulation step of accumulating the fibers on the liquid surface of a liquid tank containing a liquid to obtain a fiber aggregate, and a fiber bundle is drawn from one end of the fiber aggregate to form a fiber bundle A method for producing a twisted yarn comprising: a drawing step; a twisting step of twisting while running the fiber bundle to obtain a twisted fiber bundle; and a winding step of winding the twisted fiber bundle to obtain a twisted yarn , The twisting step is to rotate the liquid surface on which the fiber assembly is formed by rotating a stirring blade provided in the liquid tank, or to provide twisting, or to prepare for the liquid tank The fiber collection By pulling member for pulling the body from the liquid surface, after pulling up the fiber aggregate on the surface of the pulling member and gives a twist by rotating the pulling member, a method for producing a twisted yarn.

  The twisted yarn obtained by the method for producing twisted yarn of the present invention is composed of a plurality of filaments having a small fiber diameter. For this reason, the fiber structure formed from the twisted yarn of the present invention has a surface area larger than that of the conventional structure. Therefore, the obtained fiber structure should be preferably used as a substrate for cell culture. Can do.

Moreover, the twisted yarn obtained by the manufacturing method of the twisted yarn of this invention has few liquids contained in a fiber bundle. For this reason, winding is easy in the manufacturing process of twisted yarn, and productivity can be improved.
Furthermore, the twisted yarn manufacturing method of the present invention does not require a separate twisting step. For this reason, according to this invention, a twisted yarn can be obtained efficiently.

Hereinafter, the present invention will be described in detail.
<Method for producing twisted yarn>
The method for producing a twisted yarn according to the present invention includes a fiber-forming composition preparation step for preparing a fiber-forming composition containing a fiber-forming substance and a solvent, and a high voltage is applied to the fiber-forming composition to eject the fiber-forming composition. A spinning process for forming fibers, a cumulative process for accumulating the fibers on the liquid surface of a liquid tank containing a liquid to obtain a fiber aggregate, and a fiber by drawing the fiber from one end of the fiber aggregate. It includes a drawing process for forming a bundle, a twisting process in which the fiber bundle is run while being twisted to form a twisted fiber bundle, and a winding process for winding the twisted fiber bundle to obtain a twisted yarn.

  Below, each manufacturing process of the manufacturing method of the twisted yarn of this invention, the apparatus used for a process, the material which forms a fiber, etc. are demonstrated.

[Fiber-forming composition preparation step]
In the fiber-forming composition preparation step, a fiber-forming composition containing a fiber-forming substance and a solvent is prepared.
In the method for producing a twisted yarn of the present invention, first, a fiber-forming composition is obtained by mixing a fiber-forming substance and a solvent. In addition, the composition for fiber formation obtained becomes a uniform solution or dispersion. The mixing method is not particularly limited, and a known method such as stirring can be employed.

  The concentration of the fiber-forming substance in the fiber-forming composition is preferably 1% by mass to 30% by mass. When the concentration of the fiber-forming substance is less than 1% by mass, it is difficult to form fibers because the concentration is too low. On the other hand, when the concentration is larger than 30% by mass, the fiber diameter of the obtained fiber is not preferable. The concentration of the fiber-forming substance is more preferably in the range of 2% by mass to 20% by mass with respect to the entire fiber-forming composition.

  In the present invention, from the viewpoint of improving the stability of the solution or dispersion of the fiber-forming composition and the spinning stability, or from the viewpoint of imparting functionality to the obtained twisted yarn, the fiber-forming composition is used. Optional components other than the fiber-forming substance and the solvent may be added. In this case, the optional component may be added before mixing the fiber-forming substance and the solvent or after mixing them.

[Spinning process]
In the spinning step, fibers are formed by applying a high voltage to the fiber-forming composition and ejecting it. The spinning method and spinning device in the spinning process will be described below.

[Spinning method]
In the spinning step in the method for producing a twisted yarn of the present invention, fibers are produced by an electrostatic spinning method. Here, the “electrostatic spinning method” is a method in which a solution or dispersion containing a fiber-forming substrate or the like is discharged into an electrostatic field formed between electrodes, and the solution or dispersion is directed toward the electrodes. This is a method for forming a fibrous substance.

  An arbitrary method can be adopted as a method of ejecting the fiber-forming composition into the electrostatic field. For example, the fiber-forming composition is supplied to the nozzle and placed at an appropriate position in the electrostatic field, and the nozzle The fiber-forming composition is twisted by an electric field. Here, the fiber is formed between the nozzle and the electrode by eliminating the electric charge from the fiber forming composition while the fiber forming composition is drawn.

  If the room temperature is normal, the solvent contained in the fiber-forming composition completely evaporates until the fiber reaches the collection surface, but if the solvent evaporation is insufficient, The spinning atmosphere temperature may be controlled or the spinning may be performed under reduced pressure conditions. The temperature at the time of spinning depends on the evaporation behavior of the solvent contained in the fiber-forming composition and the viscosity of the fiber-forming composition (spinning solution), but is usually in the range of 0 ° C to 50 ° C. Is preferred.

  The fibrous material formed in the spinning step includes not only a state in which the solvent and the like contained in the fiber-forming composition are completely distilled off, but also a state in which the fibrous material remains in the fibrous material. In addition, the obtained fiber may be further subjected to heat treatment or chemical treatment.

[Spinning equipment]
Next, an apparatus used in the electrostatic spinning method will be described.
The electrode for forming the electrostatic field may be any material such as a metal, an inorganic material, or an organic material as long as it exhibits conductivity. Alternatively, a thin film made of a metal, an inorganic material, an organic material, or the like having conductivity may be provided over an insulator.

  The electrostatic field used in the electrostatic spinning method is formed between a pair or a plurality of electrodes, and a high voltage may be applied to any electrode that forms the electrostatic field. This includes, for example, the case of using two high voltage electrodes having different voltage values (for example, 15 kV and 10 kV) and one electrode connected to the ground, or a total of more than three electrodes. Including the case of using.

Hereinafter, the electrostatic spinning method will be described more specifically with reference to FIGS. 1 and 2.
FIG. 1 is a diagram schematically showing an example of a production apparatus for realizing the method for producing a twisted yarn of the present invention. FIG. 2 is a view of the manufacturing apparatus of FIG. 1 as viewed from above.

  The fiber-forming composition holding tank 3 has a cylindrical syringe shape. An injection needle-like fiber-forming composition ejection nozzle 1 is installed at the tip of the fiber-forming composition holding layer 3, and appropriate means such as high voltage generation is provided in the fiber-forming composition ejection nozzle 1. A voltage is applied by the vessel 4 to guide the fiber forming composition 2 to the tip of the fiber forming composition ejection nozzle 1. The tip of the fiber forming composition ejection nozzle 1 is arranged at an appropriate distance from the liquid tank 6 described later. Then, the fiber forming composition 2 is ejected from the tip portion of the fiber forming composition ejection nozzle 1, and fibers are formed between the tip portion of the fiber forming composition ejection nozzle 1 and the liquid tank 6.

  When supplying the fiber-forming composition 2 from the fiber-forming composition ejection nozzle 1 into the electrostatic field, several nozzles may be used in parallel to improve the fiber production speed and production stability. it can. In the apparatus of FIG. 1 and FIG. 2, although the eight fiber formation composition ejection nozzles 1 are installed, it is also possible to increase to eight or more.

  Here, the distance between the fiber forming composition ejection nozzle 1 and the liquid tank 6 depends on the charge amount, the nozzle size, the ejection amount of the fiber forming composition, the concentration of the fiber forming composition, and the like, but about 10 kV. In this case, a distance of 5 to 20 cm is appropriate. The applied electrostatic potential is generally in the range of 3 to 100 kV, preferably 5 to 50 kV, more preferably 5 to 30 kV. The desired potential can be generated by any appropriate method known in the art.

[Cumulative process]
In the accumulating step in the method for producing a twisted yarn of the present invention, the fibers formed in the spinning step are accumulated on the liquid surface of the liquid tank containing the liquid to obtain a fiber assembly. Specifically, the fibrous material formed in the spinning process is accumulated (laminated) using the liquid surface of the liquid tank containing the liquid as a collection surface.
In the present invention, by accumulating the fiber assembly on the liquid surface of the liquid tank in which the liquid is stored, the resistance at the time of drawing the fiber from the liquid surface is reduced in the next drawing step, and the yarn is cut off. Can be spun.
In FIG. 1 and FIG. 2, the fiber forming composition 2 is ejected from the tip of the fiber forming composition ejection nozzle 1 to form fibers, and then the fibers are accumulated on the liquid surface accommodated in the liquid tank 6 ( To obtain a fiber assembly.

(Liquid tank shape)
The shape of the liquid tank used in the method for producing a twisted yarn of the present invention is not particularly limited. It can select suitably by arrangement | positioning of the nozzle which ejects the composition for fiber formation in a spinning process. For example, an arbitrary shape such as a cylindrical shape or a polygonal column shape can be used. However, since the distance from the nozzle can be made uniform, a cylindrical shape as shown in FIG. 2 is preferable.
Moreover, it does not specifically limit about the depth of a liquid tank, What is necessary is just to be able to implement the twist process mentioned later and to set an appropriate distance from the composition formation nozzle for a fiber formation.

[Liquid contained in liquid tank]
Next, the liquid accommodated in the liquid tank will be described. The liquid accommodated in the liquid tank used in the method for producing a twisted yarn of the present invention can accumulate a fiber assembly and can produce a twisted yarn by a twisting step and a winding step described later. However, it is necessary that the fiber-forming substance does not dissolve and is a liquid having high electrical conductivity. Examples of such a liquid include water and alcohol, and water is preferable from the viewpoint of safety. Moreover, it is also possible to add inorganic salt etc., an acid, an alkali, etc. as needed.

[Drawing process]
In the drawing process, fibers are drawn from one end of the fiber assembly formed in the accumulation process to form a fiber bundle. In the method for producing a twisted yarn of the present invention, a fiber bundle can be continuously formed by pulling out one end of the fiber assembly obtained by the accumulating step, by entanglement of fibers.
The method for pulling out the fibers from the fiber assembly is not particularly limited, and any method can be used as long as it can be pulled out without breaking the yarn.

[Twisting process]
In the twisting process, the fiber bundle drawn in the drawing process is twisted while traveling to obtain a twisted fiber bundle. By twisting while running the drawn fiber bundle, the liquid contained in the fiber bundle is squeezed out in the process of pulling up the fiber bundle, thereby making it possible to produce a stable twisted yarn. In addition, since the twisting process is taken into the manufacturing process, it is not necessary to provide a separate twisting process, and thus a twisted yarn can be obtained efficiently.
The method for twisting the fiber bundle while traveling is not particularly limited, and various known methods can be employed. In particular, from the viewpoint of simplifying the winding device without using a winding device such as a winder, a method of rotating the fiber aggregate formed in the accumulation process can be preferably used.

The method for rotating the fiber aggregate obtained by the accumulation process is not particularly limited as long as the fiber aggregate can be rotated. For example, a method of rotating the liquid tank itself, using a liquid tank equipped with a stirring blade, stirring the liquid contained in the liquid tank with the stirring blade, thereby rotating the fiber aggregate accumulated on the liquid surface Examples thereof include a method, or a method of rotating the pulled fiber assembly after pulling the fiber assembly from the liquid surface of the liquid tank with the pulling body using a liquid tank provided with the pulling body.
Among these, a rotating part can be minimized and a twisting strength can be easily adjusted. Therefore, a method using a liquid tank provided with a stirring blade, or a liquid tank provided with a lifting body A method using can be preferably employed.

[Liquid tank with stirring blades]
In the method for producing a twisted yarn of the present invention, it is preferable to use a liquid tank provided with a stirring blade. By rotating the stirring blade provided in the liquid tank, a circulatory flow is generated in the liquid stored in the liquid tank, and thereby the liquid surface on which the fiber aggregate is formed can be rotated.
FIG. 1 is an example of a manufacturing apparatus using a liquid tank 6 having a stirring blade 7. The stirring blade 7 in the manufacturing apparatus of FIG. 1 is about half the diameter of the cylindrical liquid tank 6, has a shape in which two identical wings are joined, and is substantially at the center of the bottom surface of the liquid tank 6. The coupling part is provided in the part. In the twisting process, the stirring blade 7 is rotated to generate a circulatory flow in the liquid stored in the cylindrical liquid tank 6, thereby rotating the surface of the liquid and rotating the accumulated fiber assembly. give. In addition, when using the manufacturing apparatus in FIG. 1, it is preferable to make the direction which pulls out the fiber in the drawing-out process which is a pre-process into the rotating shaft direction of the stirring blade 7.
In addition, when using a liquid tank provided with a stirring blade, the size, shape, installation position, etc. of the stirring blade to be used are not particularly limited, and as a result, the surface of the liquid stored in the liquid tank is rotated. What is necessary is just to give the liquid a circulatory flow to the extent that it is possible. The twisting strength of the obtained twisted yarn can be controlled by adjusting the rotation speed of the stirring blade.

[Liquid tank with lifting body]
Moreover, in the manufacturing method of the twisted yarn of this invention, it is also preferable to use the liquid tank provided with a raising body. The fiber assembly on the pulling body can be rotated by rotating the pulling body after pulling up the fiber assembly from the liquid surface of the liquid tank by the pulling body using the liquid tank provided with the pulling body.
FIG. 3 is an example of a manufacturing apparatus using a liquid tank 6 provided with a lifting body 8. The lifting body 8 in the manufacturing apparatus of FIG. 3 is about half the diameter of the cylindrical liquid tank 6, has a conical shape, and the apex of the cone is approximately at the center of the circumference of the liquid tank 6. It is provided to be located. In the twisting process, after the fiber assembly is pulled up by the lifting body 8, the lifting body 8 is rotated to rotate the fiber assembly pulled up on the lifting body 8. In the case where the manufacturing apparatus in FIG. 3 is used, it is preferable that the pulling-out direction of the fiber in the pulling-out process, which is a previous process, is the rotational axis direction of the pulling body 8.
In addition, when using the liquid tank provided with the lifting body, the material, size, shape, installation position, etc. of the lifting body to be used are not particularly limited, and as a result, the fiber assembly can be pulled up and pulled up. Anything that can be rotated after that is acceptable. The twisting strength of the resulting twisted yarn can be controlled by adjusting the rotational speed of the lifting body.
The twist strength in the method for producing a twisted yarn of the present invention is not particularly limited, and can be appropriately selected according to the use for which the obtained twisted yarn is used.

[Winding process]
In the winding process, the twisted fiber bundle that has been twisted in the twisting process is wound to obtain a twisted yarn. The winding method is not particularly limited, and a known method can be adopted, and examples thereof include a method of continuously winding at a constant speed using a winding roller or the like.
In the method for producing a twisted yarn of the present invention, the obtained twisted yarn may be further subjected to a heat treatment, a chemical treatment, a stretching treatment, or the like.

[Fiber-forming composition]
The composition for fiber formation used for the manufacturing method of the twisted yarn of this invention is demonstrated. The fiber-forming composition is a composition containing a fiber-forming substance and a solvent as essential components.

[Fiber-forming substance]
The fiber-forming substance used in the present invention is not particularly limited as long as it can produce fibers by an electrospinning method. However, from the viewpoint of handling, an organic polymer is preferable. Examples of organic polymers that can be used include polyvinyl chloride, polyacrylonitrile, polylactic acid, polyglycolic acid, polylactic acid-polyglycolic acid copolymer, polycaprolactone, polybutylene succinate, polyethylene succinate, polystyrene, Polycarbonate, polyhexamethylene carbonate, polyarylate, polyvinyl isocyanate, polybutyl isocyanate, polymethyl methacrylate, polyethyl methacrylate, polynormal propyl methacrylate, polynormal butyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyethylene terephthalate, Polytrimethylene terephthalate, polyethylene naphthalate, polyparaphenylene terephthalamide, Riparaphenylene terephthalamide-3,4'-oxydiphenylene terephthalamide copolymer, polymetaphenylene isophthalamide, cellulose diacetate, cellulose triacetate, methylcellulose, propylcellulose, benzylcellulose, fibroin, natural rubber, polyvinyl Acetate, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl normal propyl ether, polyvinyl isopropyl ether, polyvinyl normal butyl ether, polyvinyl isobutyl ether, polyvinyl tertiary butyl ether, polyvinylidene chloride, poly (N-vinylpyrrolidone), poly (N-vinylcarba Sol), poly (4-vinylpyridine), polyvinyl methyl ketone, polymethyl isopropenyl ketone, poly Oxide, polypropylene oxide, polycyclopentene oxide, polystyrene sulfone, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, and can be exemplified copolymers thereof.

〔solvent〕
The solvent used as an essential component of the fiber-forming composition may be used alone or in combination of a plurality of solvents. The solvent that can be used in the present invention is not particularly limited as long as it can dissolve or disperse the fiber-forming substance and can evaporate in the spinning process by the electrospinning method to form fibers. is not. For example, acetone, chloroform, ethanol, isopropanol, methanol, toluene, tetrahydrofuran, water, benzene, benzyl alcohol, 1,4-dioxane, propanol, methylene chloride, carbon tetrachloride, cyclohexane, cyclohexanone, phenol, pyridine, trichloroethane, acetic acid, Examples include formic acid, hexafluoroisopropanol, hexafluoroacetone, N, N-dimethylformamide, acetonitrile, N-methylmorpholine-N-oxide, 1,3-dioxolane, methyl ethyl ketone, and mixed solvents thereof.

[Optional ingredients]
In the method for producing a twisted yarn of the present invention, fibers can be formed from the fiber forming composition, and components other than the essential components described above are optional components of the fiber forming composition as long as they do not exceed the gist of the present invention. You may make it contain.
Examples of such optional components include additives such as emulsions, organic or inorganic powders, drugs, and the like. By adding an optional component, it is possible to improve the stability of the solution or dispersion of the fiber-forming composition or the spinning, or to impart functionality to the obtained twisted yarn.
In the case of using a drug, not only a low molecular compound drug having high compatibility with a fiber-forming substance, but also a compound having low compatibility, by dispersing drug granules or the like in the fiber-forming composition, The drug can be dispersed in the filament constituting the twisted yarn. When the filament constituting the twisted yarn of the present invention contains a drug, it becomes a twisted yarn having a function of sustained drug release.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these unless it exceeds the gist.
<Measurement and evaluation method>
In the examples, the following items were measured and evaluated by the following methods.
[Average fiber diameter of twisted yarn]
Ten locations were randomly selected from the obtained twisted yarn. For the selected location, photographed with an optical microscope (trade name: Eclipse E600W, manufactured by Nikon Corporation) (magnification: 10 times), and in the obtained photographic diagram, when the cross section of the twisted yarn is a circle, the diameter is the fiber diameter, In the case of an ellipse, the fiber diameter (n = 10) was measured with the average of the long and short diameters as the fiber diameter, and the average value of all these (n = 10) was taken as the average fiber diameter of the twisted yarn.
[Average filament fiber diameter]
The surface of the obtained twisted yarn was photographed (magnification: 8000 times) with a scanning electron microscope (manufactured by Hitachi, Ltd., model: S-2400), and 20 spots were selected at random from the obtained photograph. The diameter of the filament constituting the twisted yarn was measured, and the average value of all these fiber diameters (n = 20) was taken as the average fiber diameter of the filament.

<Example 1>
[Preparation of fiber-forming composition]
1 part by mass of polylactic acid (manufactured by Shimadzu Corporation, trade name: Lacty 9031), 3 parts by mass of ethanol (manufactured by Wako Pure Chemical Industries, grade: special grade), 6 parts by mass of methylene chloride (manufactured by Wako Pure Chemical Industries, grade: special grade) The parts were mixed at room temperature (25 ° C.) to prepare a fiber-forming composition.

[Spinning process / Cumulative process]
The fiber forming composition was ejected using the apparatus shown in FIG. 1 to obtain a fiber assembly. Various settings in the apparatus are as follows.
Inner diameter of fiber forming composition jet nozzle 1: 0.8 mm
Voltage: 15kV
Distance from the fiber forming composition ejection nozzle 1 to the liquid surface accommodated in the liquid tank 6: 5 cm
Diameter of liquid tank 6: 10 cm, height: 22 cm
Stirring blade 7 width: 5 cm, height: 2 cm

[Drawing process, twisting process, winding process]
Using tweezers, fibers are drawn from one end of the fiber assembly obtained above to form a fiber bundle, and the stirring blade 6 is rotated so that the fiber assembly formed on the liquid surface accommodated in the liquid tank 6 Was wound by the take-up roller 5 while twisting the fiber bundle. Various settings in the apparatus are as follows.
Distance from the surface of the liquid stored in the liquid tank 6 to the take-up roller 5: 25 cm
Rotating speed of stirring blade 7: 300 rpm
Winding speed of the winding roller 11: 0.5 m / min

[Evaluation of twisted yarn]
The obtained twisted yarn had an average fiber diameter of 2 mm and a fineness of 100 dtex. Further, the average fiber diameter of the filaments constituting the twisted yarn was 200 nm.

<Comparative Example 1>
An attempt was made to obtain a fiber bundle that was not twisted by the same operation as in Example 1 except that the stirring blade 6 was not rotated (except that the twisting step was not performed). However, since the fiber bundle is swollen by the liquid, the yarn is broken by its own weight, and stable winding cannot be performed.

It is the figure which showed typically the example of the manufacturing apparatus for implement | achieving the manufacturing method of the twisted yarn of this invention. It is the figure which looked at the manufacturing apparatus of FIG. 1 from the upper part. It is the figure which showed typically another example of the manufacturing apparatus for implement | achieving the manufacturing method of the twisted yarn of this invention. It is the figure which looked at the manufacturing apparatus of FIG. 3 from the upper part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fiber formation composition ejection nozzle 2 Fiber formation composition 3 Fiber formation composition holding tank 4 High voltage generator 5 Winding roller 6 Liquid tank 7 Stirring blade 8 Pull-up body

Claims (1)

A fiber-forming composition preparation step of preparing a fiber-forming composition comprising a fiber-forming substance and a solvent;
A spinning step of forming fibers by applying a high voltage to the fiber-forming composition and ejecting the composition;
A cumulative step of accumulating the fibers on the liquid surface of the liquid tank containing the liquid to obtain a fiber assembly;
A drawing step of drawing a fiber from one end of the fiber assembly to form a fiber bundle;
Twisting step to twist the fiber bundle while running the fiber bundle,
A winding step of winding the twisted fiber bundle to obtain a twisted yarn , wherein the twisting step comprises rotating the stirring blade provided in the liquid tank to rotate the fiber assembly. The liquid surface on which the liquid is formed is twisted by rotating the liquid surface, or provided on the liquid tank, the pulling body for pulling up the fiber assembly from the liquid surface, to the surface of the pulling body A method for producing a twisted yarn, wherein the fiber assembly is pulled up and then the pulled body is rotated to give twist.

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