KR101723904B1 - Preparation Method of Hollow Fiber Membrane With Improved Processing Efficiency And Manufacturing System Thereof - Google Patents

Abstract

The present invention relates to a hollow fiber membrane manufacturing method and an apparatus for spinning hollow fiber membranes, the method comprising the steps of: discharging an inner coagulating solution into an inner nozzle of a double nozzle and discharging a spinning solution to an outer nozzle;
Forming a hollow fiber by solidifying the yarn radiated in the step in a coagulation bath;
Washing the hollow fiber formed in the step in a water bath; And
Winding the hollow fiber washed in the step in a take-up roll,
The distance between the water bath and the winding roll is within 10 m,
The present invention provides a method for producing a hollow fiber membrane in which the tension of a hollow fiber is uniformly maintained in a range of 100 to 700 g / mm ² between a water bath and a winding roll.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a hollow fiber membrane,

A manufacturing method of the hollow fiber membrane, and a facility for radiating the hollow fiber membrane.

Membrane technology is a highly sophisticated separation technique for almost completely separating and removing the material to be treated present in the treatment water according to pore size, pore distribution and membrane surface charge of the membrane. In addition, the separation membrane technology has been widely applied in the field of water treatment, such as production of drinking water and industrial water of good quality, purification / reuse of waste water / wastewater, and clean production process related to the development of a no-discharge system.

In particular, membrane technology using hollow fiber membranes has become one of the key technologies that will be noticed in the 21st century. The hollow fiber membrane used in the water treatment process is a characteristic that affects the water treatment ability and has a mechanical strength to prolong the service life; Various water properties such as water permeability associated with the treatment cost are required.

Apart from the required properties of such a hollow fiber membrane, the monofilament phenomenon generated in the process of producing the hollow fiber membrane causes the production yield to be significantly lowered. The single yarn phenomenon occurring in the spinning process is a cause of inhibiting the continuous progress of the manufacturing process of the hollow fiber membrane, and thus the production yield of the hollow fiber membrane is significantly lowered.

Korean Patent Publication No. 2014-0037761

Disclosed is a hollow fiber membrane manufacturing method and a hollow fiber membrane spinning apparatus capable of effectively preventing a single yarn in a manufacturing process without causing deterioration of physical properties of the hollow fiber membrane.

A method of manufacturing a hollow fiber membrane according to an embodiment of the present invention includes:

Discharging the inner coagulating solution with the inner nozzle of the double nozzle and discharging the spinning solution to the outer nozzle to spin the yarn;

Forming a hollow fiber by solidifying the yarn radiated in the step in a coagulation bath;

Washing the hollow fiber formed in the step in a water bath; And

Winding the hollow fiber washed in the step in a take-up roll,

The distance between the water bath and the winding roll is within 10 m,

The tension of the hollow fiber between the water bath and the winding roll is in the range of 100 to 700 g / mm ² .

According to another embodiment of the present invention,

First and second storage tanks for storing the spinning stock solution and the inner coagulating solution, respectively;

A double nozzle for discharging the spinning stock solution supplied from the first storage tank to the outer nozzle and discharging the inner coagulating solution supplied from the second storage tank to the inner nozzle to spin the yarn;

A coagulation tank for coagulating the yarn radiated from the double nozzle to form a hollow fiber;

A water bath for washing the hollow fiber formed in the coagulation bath;

A winding roll installed within 10 m of the water bath; And

And a condenser for constantly controlling the tension of the hollow fiber between the water bath and the winding roll in the range of 100 to 700 g / mm ² .

Disclosure of Invention Technical Problem [10] The present invention provides a hollow fiber membrane having improved elongation, preventing the single yarn of the hollow fiber yarn during the production of the hollow fiber membrane, improving the process efficiency, and the like.

1 is a schematic view schematically showing a radiation facility according to one embodiment of the present invention.
2 to 3 are images showing the results of observing the cross section of the hollow fiber membrane according to the embodiment or the comparative example with an electron microscope (SEM).

In the present invention, "strength" means a value obtained by dividing the load at the breaking point by the initial unit area, and "elongation" means elongation percentage of the produced hollow fiber membrane. In the present invention, The elongation was measured. In the present invention, "water permeability" means a value obtained by measuring the amount of ultrapure water that has passed through a unit area with a certain pressure applied thereto, and "stress" means a force generated in the hollow fiber at the time of producing the hollow fiber, Also called tension.

The term "asymmetric structure" in the present invention means an average size variation of pores formed in the direction of the outer surface layer and the inner surface layer, respectively, with reference to a midpoint between an arbitrary point of the inner surface layer of the hollow fiber and the corresponding point of the outer surface layer Which means that the values are different.

In addition, in the present invention, "weight portion" means a weight ratio between the components.

The present invention provides a method for producing a hollow fiber membrane with improved elongation and water permeability.

As one example, the method for producing the hollow fiber membrane includes:

Discharging the inner coagulating solution with the inner nozzle of the double nozzle and discharging the spinning solution to the outer nozzle to spin the yarn;

Forming a hollow fiber by solidifying the yarn radiated in the step in a coagulation bath;

Washing the hollow fiber formed in the step in a water bath; And

Winding the hollow fiber washed in the step in a take-up roll,

The distance between the water bath and the winding roll is within 10 m,

The tension of the hollow fiber between the water bath and the winding roll may be in the range of 100 to 700 g / mm ² .

In the present invention, the distance between the water bath and the winding roll is controlled within 10 m, and the average stress of the hollow yarn between the water bath and the winding roll is controlled, thereby improving the elongation at the time of producing the hollow fiber membrane and significantly reducing the single yarn ratio. If the time during which the washed hollow fiber is exposed to the outside air in the winding process in the winding roll is prolonged, a temperature deviation may occur by the length. Such a temperature deviation may deteriorate the quality of the hollow fiber membrane and, in some cases, may act as a cause of causing single yarn. Therefore, the distance between the water bath and the winding roll can be controlled to be short, the time to be exposed to the outside air can be reduced, and the occurrence of the temperature deviation can be reduced. The distance between the water bath and the winding roll can be controlled within 8 m or within 5 m, and the winding roll can be located inside the winding drum.

The tension of the hollow fiber between the water bath and the winding roll may be in the range of 100 to 700 g / mm ² . Specifically, the stress may be in the range of 100 to 700 g / mm ² , 100 to 650 g / mm ² , 120 to 400 g / mm ^2, or 130 to 300 g / mm ² . The stress of the hollow fiber between the water bath and the winding roll can be controlled by using a denser which is a device for keeping the stress constant. By adjusting the average stress of the hollow yarn between the water bath and the winding yarn to the above range, the yarn ratio can be remarkably reduced by controlling the stress and tensile force applied to the yarn during the spinning process, and the elongation of the hollow fiber membrane can be improved . If the stress of the hollow fiber is 100 g / mm ² , The yarn is not wound, and when the stress exceeds 700 g / mm ² , the elongation may be lowered. Therefore, by controlling the average stress of the hollow yarn between the water washing tank and the winding roll in the range according to the present invention, the above problems can be prevented.

As another example, the spinning speed of the hollow fiber may satisfy the following general formula (1) in the water bath and the winding roll.

[Formula 1]

_{1.1 ≤ W S / R S ≤} 2.5

In the above formula, W _S represents the spinning speed (m / min) of the yarn in the winding roll, and R _S represents the spinning speed (m / min) of the yarn in the spinning bath.

Specifically, the spinning speed of the yarn in the spinning roll and the spinning speed ratio of the yarn in the spinning bath means the spinning ratio of the yarn in the spinning bath and the spinning roll, and the spinning ratio is 1.1 to 2.5, 1.1 to 2.3, 1.2 to 2.1 Or in the range of 1.3 to 2.0. By controlling the yarn spinning speed in the kneading roll and the yarn spinning speed ratio in the water bath in the above range, it is possible to manufacture a high quality hollow fiber membrane with improved elongation and strength, and effectively prevent a single yarn phenomenon in the manufacturing process.

As an example, the yarn spinning rate R _S in the winding roll may range from 10 to 55 m / min, from 15 to 53 m / min, from 20 to 50 m / min or from 25 to 45 m / min. The spinning speed (W _S ) of the yarn in the water bath may be 10 to 40 m / min, 15 to 35 m / min, or 20 m / min.

As another example, the temperature deviation of the outside air through which the hollow fiber membrane is exposed can be controlled within 2 占 폚, and the humidity deviation can be controlled within 5% between the water bath and the winding roll. Specifically, the temperature deviation can be controlled within 1 占 폚, and the humidity deviation can be controlled within 3%. If the time during which the washed hollow fiber is exposed to the air during the winding process in the winding roll is prolonged, temperature and humidity deviations may occur by length. Such temperature and humidity deviations may deteriorate the quality of the hollow fiber membrane, and in some cases may act as a cause of inducing single yarn. Therefore, it is an object of the present invention to provide a hollow fiber membrane capable of producing a hollow fiber membrane having remarkably improved elongation by minimizing the temperature and humidity deviation of the outside air through which the hollow fiber membrane is exposed, Can be effectively prevented.

As yet another example, the elongation of the hollow fiber membrane according to the present invention may range from 55 to 80%. Specifically, the elongation may be 60% or more, 65% or more, or 70% or more. In the present invention, the water bath and the winding roll are spaced within 10 m, the stress of the hollow fiber is controlled between the water bath and the winding roll, and the temperature and humidity of the outside air are controlled to be constant. Thereby effectively preventing the phenomenon that the hollow fiber is wound in a single direction.

As an example of the method for producing the hollow fiber membrane, the spinning solution may be a matrix resin; A crosslinking resin; Pore formers; menstruum; And non-solvent, and the average discharge speed of the spinning stock solution may be 20 g / min to 40 g / min. Specifically, the average spinning rate of the spinning liquid is 20 g / min to 30 g / min, 20 g / min to 25 g / min, 25 g / min to 35 g / min, or 35 g / min to 40 g / min Lt; / RTI > The discharge speed of the inner spinning liquid is controlled in accordance with the average discharge speed of the spinning stock solution. For example, the average discharge speed of the spinning stock solution can be controlled to 30 g / min and the average discharge speed of the internal spinning solution can be controlled to 10 g / min.

At this time, the spinning viscosity of the spinning solution may be in the range of 20,000 to 30,000 cps. Specifically, the viscosity may range from 21,000 to 28,000 cps, 21,000 to 27,000 cps, 22,000 to 25,500 cps, 22,000 to 25,000 cps, 22,500 to 25,000 cps, or 23,000 to 24,500 cps. By controlling the spinning viscosity of the spinning stock solution in the above range, the pore size and pore distribution can be controlled appropriately and excellent water permeability can be realized.

The hollow fiber membrane produced by the method of manufacturing a hollow fiber membrane according to the present invention includes pores having a symmetrical structure, and the pores may include a structure formed on an outer surface layer and an inner surface layer. Accordingly, the mechanical strength, elongation and water permeability of the hollow fiber membrane can be improved at the same time. In addition, the hollow fiber membrane has high hydrophilicity, and water permeability can be improved, and the fouling reduction effect is excellent, so that size and shape deformation due to excessive chemical treatment of pores formed in the inner and outer hollow fiber membranes can be prevented.

At this time, the matrix resin is not particularly limited as long as it can form a hollow fiber membrane. As one example, polysulfone, polyethersulfone, or a mixture thereof may be used as the base resin as the matrix resin. Polysulfone resins are excellent in heat resistance, have a wide pH range to be applied, and are excellent in solubility in solvents, thus facilitating conditioning of a spinning dope. In the present invention, the type of the matrix resin is not particularly limited and may be, for example, a resin containing polyvinylidene fluoride.

The crosslinking resin is not particularly limited as long as it can form a crosslink in the matrix resin. The crosslinking resin induces crosslinking of the polysulfone-based hollow fiber membrane, affects hydrophilicity imparting, and is closely related to water permeability. For example, the crosslinking resin provides cross-linkage of the hydrophilic group inside the polysulfone resin to increase the hydrophilicity of the polysulfone-based hollow fiber. Examples of the type of the crosslinking resin include polyvinylpyrrolidone, cellulose acetate, polyacrylamide (PAAm), and polyvinyl alcohol (PVA) And may include at least one kind selected.

Further, the pore-forming agent is not particularly limited as long as it forms pores through phase conversion with non-solvent. Pore-forming agents affect pore formation of hollow fiber membranes and are closely related to water permeability. As one example, the pore forming agent present in the spinning stock solution may absorb the non-solvent of the coagulation tank while the spinning stock solution is discharged from the double nozzle and then stays in the coagulation tank, so that the spinning stock solution can be easily converted into the solvent. In addition, the pore-forming agent serves as a swelling agent and provides an effect of increasing the pore size. The pore-forming agent may be at least one selected from the group consisting of polyethyleneglycol, glycerin, polypropyleneglycol, and castor oil, for example. For example, as the pore-forming agent, polyethylene glycol having a weight average molecular weight of 800 or less may be used. The pore-forming agent forms a pore by converting the spinning yarn into a coagulating solution and converting it into a non-solvent. If the weight average molecular weight of the pore-forming agent is excessively large, the phase change speed is slowed, and the pore size formed thereby becomes large. For example, when a pore-forming agent having a large weight average molecular weight is used in the production of a hollow fiber membrane, a hollow fiber membrane having a pore structure of a finger structure can be produced.

The type of the solvent is not particularly limited and includes, for example, dimethylacetamide (DMAc), dimethylformamide (DMF), chloroform, N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP), and dimethylsulfoxide (DMSO). For example, dimethylacetamide (DMAc) may be used as the solvent.

In addition, the type of the non-solvent is not particularly limited, and water, alcohol, methyl alcohol or a mixture thereof may be used. For example, ultrapure water can be used as a non-solvent.

Wherein the spinning stock solution comprises:

10 to 35 parts by weight of a matrix resin;

10 to 30 parts by weight of a pore-forming agent;

2 to 10 parts by weight of a crosslinking resin;

40 to 65 parts by weight of a solvent; And

And 2 to 10 parts by weight of the non-solvent.

More specifically, the spinning stock solution may be a polysulfone-based matrix resin as a matrix resin, 10 to 30 parts by weight of a matrix resin per 100 parts by weight of the spinning solution; 10 to 28 parts by weight; 15 to 30 parts by weight; 28 to 30 parts by weight; 19 to 25 parts by weight; 20 to 27 parts by weight; Or 19 to 22 parts by weight, which is disclosed as an example, and the scope of the present invention is not limited thereto.

Further, the internal coagulating liquid may be prepared by adding 3 to 60 parts by weight of non-solvent; And 40 to 97 parts by weight of a solvent.

In the method of manufacturing the hollow fiber membrane, the temperature of the spinning solution may be controlled to be in the range of 20 to 35 占 폚 and the temperature of the inner coagulating solution may be controlled in the range of 40 to 60 占 폚. In the present invention, the size and distribution of pores can be appropriately controlled by controlling the temperature of the spinning stock solution and the inner coagulating solution. That is, by applying the hybrid phase separation method in which the solvent-induced phase separation method and the heat-induced phase separation method can be performed at the time of phase change, pores having a relatively large diameter are formed in the outer surface layer of the hollow fiber membrane as compared with the pores formed in the inner surface layer It is possible to enhance the mechanical strength of the hollow fiber membrane and realize an asymmetric structure of pores for improving water permeation and filtration performance.

In one embodiment, the present invention provides a hollow fiber spinning facility.

The hollow fiber membrane spinning apparatus includes:

First and second storage tanks for storing the spinning stock solution and the inner coagulating solution, respectively;

A double nozzle for discharging the spinning stock solution supplied from the first storage tank to the outer nozzle and discharging the inner coagulating solution supplied from the second storage tank to the inner nozzle to spin the yarn;

A coagulation tank for coagulating the yarn radiated from the double nozzle to form a hollow fiber;

A water bath for washing the hollow fiber formed in the coagulation bath;

A winding roll installed within 10 m of the water bath; And

And a condenser for uniformly controlling the tensile strength of the hollow fiber between the water bath and the winding drum in the range of 100 to 700 g / mm ² .

It is preferable that the distance between the water bath and the winding roll is relatively short. When the hollow fiber washed in a water bath is wound up and exposed to the outside air for a long time, a temperature deviation may occur depending on the length. Such a temperature deviation may deteriorate the quality of the hollow fiber membrane and, in some cases, may act as a cause of causing single yarn.

The hollow fiber spinning speed in the hollow fiber membrane spinning apparatus according to the present invention can satisfy the following general formula 2 in the water bath and the winding roll.

 [Formula 2]

_{1.1 ≤ W S / R S ≤} 2.5

In the above equation, W _S represents the spinning speed (m / min) of the yarn in the spinning roll, and R _S represents the spinning speed (m / min) of the yarn in the spinning bath.

The ratio of the spinning speed of the yarn in the spinning roll and the spinning speed of the yarn in the spinning bath means the spinning ratio of the yarn in the spinning roll and the spinning bath. By controlling the stretching ratio of the yarn in the above range, a high quality hollow fiber membrane And it is possible to effectively prevent the phenomenon that the hollow fiber is united in the manufacturing process.

A schematic representation of the spinning process of the present invention is shown in Fig. 1 as an example. 1, a spinning apparatus according to the present invention includes a first storage tank 11 for storing and supplying a spinning dope, a second storage tank 12 for storing and supplying an inner coagulating liquid, The double nozzle 30, the air gap 40, the coagulation tank 50, the water tank 60, and the first and second gear pumps 21, A stretching tank 70, and a winding-up tank 80 in which a winding roll is formed.

In the first and second storage tanks 11 and 12 and the double nozzle 30 process line, a temperature system can be constructed to control and maintain the temperature in the range of 25 to 200 ° C.

The first gear pump 21 controls the rate at which the spinning stock solution supplied from the first storage tank 11 is discharged through the double nozzle 30 to 30 g / min. The second gear pump 22 controls the rate at which the internal coagulation liquid supplied from the second storage tank 12 is discharged through the double nozzle 30 at a rate of 10 g / min.

A distance L _a1 between the first storage tank 11 and the first gear pump 21 and a distance L _a2 between the first gear pump 21 and the double nozzle 31 are in a ratio of 4: . The distance L _b1 between the second storage tank 12 and the second gear pump 22 and the distance L _b2 between the second gear pump 22 and the double nozzle 31 are also 4: .

The double nozzle 30 has a sectional area of 1.33 mm ² with respect to the external nozzle. The double nozzle 30 can be manufactured to move vertically and horizontally in the cradle to adjust the air gap 40 between the double pipe type nozzle 30 and the coagulation bath 50. The air gap 40 is a section in which the first-order phase change occurs, and the water in the air and the organic solvent in the spinning liquid are exchanged for phase change.

The coagulation tank 50 coagulates the yarn radiated from the double nozzle 30 to form a hollow fiber and at the same time a secondary phase change occurs. In order to extend the phase change time, the coagulation tank 50 is provided with a multi- (Godet Roller) was installed to extend the residence time of the separator.

Also, by providing a multi-stage godet roller in the water tank 60, the residence time can be adjusted. The retention stage of the water treatment tank (60) is a stage where the phase of the spinning stock solution, in which the phase change in the coagulation tank (50) is not completed, is converted into a tertiary phase and washing of the inner coagulating solution is performed.

The longer the total residence time, the more advantageous for phase change and cleaning, but the longer the production process time and the lower the productivity, so it is desirable to select the optimum condition at an appropriate level.

As the specific spinning process condition, the prepared spinning stock solution and inner coagulating solution are discharged by using the double nozzle 30 to spin the yarn, and the first phase is changed in the air gap (40, air gap). And then passes through the coagulation bath (50) to perform the second phase conversion. Thereafter, the additive and residual organic solvent are removed from the water treatment tank 60, and the water is transferred to the winding drum 80 and wound, thereby completing the spinning process.

The distance between the water treatment tank (60) and the winding drum (80) is controlled within 10 m.

Furthermore, the present invention provides a water treatment module including a hollow fiber membrane manufactured by the manufacturing method or the spinning facility described above.

As one example, a water treatment module according to the present invention comprises:

A hollow fiber membrane module including a plurality of hollow fiber membranes and a potting portion for fixing one or both ends of the hollow fiber membranes;

A hollow housing into which the hollow fiber membrane module is inserted; And

And a housing cap which is located at one or both ends of the hollow housing and has a pipe connecting portion to which the fluid connecting pipe is connected.

The fluid connection pipe is not particularly limited and may include, for example, at least one of a water supply target water supply line, an air injection line, a purified water discharge line, and a concentrated water discharge line.

Hereinafter, the present invention will be described in detail by way of Examples and the like according to the present invention, but the scope of the present invention is not limited thereto.

Example  1 to 3, Comparative Example  1 and 2

First, a spinning stock solution containing a matrix resin and an inner coagulating solution were prepared with the composition shown in Table 1 below. The contents of polyisocyanurate (PES), dimethylacetamide (DMAc), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and water in Table 1 are shown in parts by weight.

ingredient Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Spinning liquid PES 20 20 20 20 20 DMAc 50 50 50 50 50 PVP 5 5 5 5 5 PEG 19 19 19 19 19 water 6 6 6 6 6 Viscosity (cps) 24000 24000 24000 24000 24000 Internal coagulation amount DMAc / water content (parts by weight) 80/20 80/20 80/20 80/20 80/20

Thereafter, the prepared spinning solution and inner coagulating solution were spun under the conditions shown in Table 2 below.

Radiation condition Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Radiation temperature
(° C) Spinning liquid 25 25 25 25 25 Internal coagulation amount 50 50 50 50 50 Spinning speed
(m / min) Washing machine 20 20 20 20 20 Winding 30 40 50 60 21 Stretching cost 1.5 2 2.5 3 1.05 Stress (g / mm ² ) 150 200 600 800 50

Experimental Example  1: Electron microscope ( SEM ) observe

Sections of the polysulfone-based hollow fiber membranes prepared in Examples 1 and 2 were observed with an electron microscope (SEM). At this time, the magnification (SEM) of the electron microscope was 100 times magnification, and the observed results are shown in Figs. 2 to 3, respectively.

FIG. 2 shows the results of observation of the hollow fiber membrane according to Example 1. It can be confirmed that the hollow fiber membrane has an asymmetric porous structure in which the pore size is continuously increased from the outer surface layer to the inner surface layer. In addition, it was confirmed that the average diameter of the pores formed in the outer surface layer was 0.01 to 0.2 μm.

Further, FIG. 3 shows the result of observing the polysulfone-based hollow fiber membrane according to Comparative Example 2, and it can be confirmed that the hollow fiber membrane according to Comparative Example 2 has irregular macropores on its cross section.

From these results, the polysulfone-based hollow fiber membrane according to the present invention can effectively produce an asymmetric porous hollow fiber membrane whose pore size is continuously increased from the outer surface layer to the inner surface layer by controlling the spinning conditions in the production of the hollow fiber membrane .

Experimental Example  2: elongation of hollow fiber membrane and cinnabar  Frequency rating

In the process of manufacturing hollow fiber membranes by the methods according to Examples 1 to 3 and Comparative Example 1, the number of single yarns was evaluated. The evaluation was conducted by irradiating the yarn for 24 hours, and calculating the number of times the single yarn occurred during the spinning. The tensile strength and elongation test of KSKISO 5079 fiber were measured for the elongation of the hollow fiber membrane. The results are shown in Table 3 below.

Properties Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Number of single yarns
(Times, based on 24hr) 0 0 0 10 - Shinto (%) 75 65 57 30 -

Referring to the results of Table 3, it was confirmed that single spinning did not occur when the spinning was carried out according to the methods of Examples 1 to 3, and the elongation was remarkably improved. However, in the case of Comparative Example 1, ten yarns were produced and the elongation was as low as 30%. In Comparative Example 2, the stress between the water bath and the winding roll was controlled to be 50 g / mm ² , The number of yarn counts and elongation could not be evaluated.

Accordingly, the manufacturing method and the spinning apparatus according to the present invention can improve the elongation by appropriately controlling the stress of the yarn, adjusting the spinning speed and the stretching ratio of the yarn in the washing tank and the winding drum, .

11: first storage tank 12: second storage tank
21: first gear pump 22: second gear pump
30: double nozzle 40: air gap
50: coagulation bath 60: water bath
70: drawing machine 80: winding machine

Claims (7)

The inner coagulating liquid is discharged by the inner nozzle of the double nozzle, and the matrix resin is injected into the outer nozzle. A crosslinking resin; Pore formers; menstruum; And discharging a spinning stock solution containing a non-spinning agent to spin the yarn;
Forming a hollow fiber by solidifying the yarn radiated in the step in a coagulation bath;
Washing the hollow fiber formed in the step in a water bath; And
Winding the hollow fiber washed in the step in a winding roll,
The temperature of the spinning liquid and the inner coagulating liquid at the time of spinning of the yarn is 20 to 35 DEG C and 40 to 60 DEG C respectively and the viscosity of the spinning liquid is 20,000 to 30,000 cps,
The crosslinking resin is at least one selected from the group consisting of polyvinyl pyrrolidone, cellulose acetate, polyacrylamide and polyvinyl alcohol,
The pore-forming agent may be at least one selected from the group consisting of polyethylene glycol, glycerin, polypropylene glycol, and castor oil,
The distance between the water bath and the winding roll is within 10 m,
Between the water bath and the winding roll, the temperature deviation of the outside air through which the hollow fiber membrane is exposed is controlled within 2 占 폚, the humidity deviation is controlled within 5%
The tension of the hollow fiber between the water bath and the winding roll was kept constant in the range of 150 to 600 g / mm ² ,
Wherein the hollow fiber spinning speed satisfies the following general formula (1) in the water bath and the winding roll:
[Formula 1]
_{1.3 ≤ W S / R S ≤} 2.5
In the above formula, W _S represents the spinning speed (m / min) of the yarn in the winding roll, and R _S represents the spinning speed (m / min) of the yarn in the spinning bath.
delete delete The method according to claim 1,
The elongation of the hollow fiber membrane is in the range of 55 to 80%.
The method according to claim 1,
The spinning liquid may be a matrix resin; A crosslinking resin; Pore formers; menstruum; And non-payment,
Wherein the average spinning rate of the spinning solution is in the range of 20 g / min to 40 g / min.
delete delete

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