KR20170075849A - Lyocell Material For Cigarette Filter and Method of the Same - Google Patents

Abstract

The present invention relates to a method for producing a lyocell radial dope comprising the steps of (S1) radiating a lyocell radial dope comprising 8 to 13% by weight of a cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine-Noxide (NMMO) ; (S2) solidifying the lyocell radiation dope radiated in the step (S1) to obtain a lyocell multifilament; (S3) washing the lyocell multifilament obtained in the step (S2); (S4) emulsifying the lyocell multifilament washed in the step (S3); And (S5) crimping the lyocell multifilament treated with the emulsion in the step (S4) by applying steam and pressure at a temperature of 120 to 250 ° C. The present invention relates to a method for producing a lyocell material for a cigarette filter, And a lyocell material for a cigarette filter manufactured therefrom.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a lyocell material for a cigarette filter,

The present invention relates to a lyocell material for a cigarette filter and a method of manufacturing the same.

Most of the cigarette filters consist of cellulose acetate fibers. Cellulose acetate fibers are currently being manufactured in the following manner. First, a flake of cellulose acetate as a raw material is dissolved in a solvent such as acetone to prepare a spinning stock solution of cellulose acetate. The spinning stock solution is fed to a spinning nozzle apparatus and spinning is carried out by dry spinning in which the spinning solution is discharged into a high temperature atmosphere to obtain a cellulose acetate fiber.

Particularly, in order to facilitate the production of the cigarette filter, the cellulose acetate fiber used as the fiber for the cigarette filter is completed as a fiber tow in which the total fineness is appropriately set and the crimp band is formed. The tobacco filter is produced by cutting the cellulose acetate fiber tow with a winding device of a cigarette filter plug, attaching a plasticizer, forming it into a rod shape with a filter winding paper, .

Often, cellulose acetate is acetic acid esterified cellulose and is known to be essentially biodegradable. However, a cigarette filter made of cellulose acetate fiber still retains its original shape for 1-2 years even if buried in the soil, and it takes a considerably long time until the cigarette filter buried in the soil is completely biodegraded.

The cigarette filter is assembled into a tobacco product, distributed to consumers, provided to smoking cigarettes, and finally discarded after cigarette smoking. In addition, the cigarette filter may be disposed of directly as a manufacturing residue from a cigarette filter manufacturing plant. These tobacco filter wastes are recovered as refuse and buried for the treatment. Smoking of cigarettes may be left in a natural environment without being collected as garbage in some cases. Cigarette filters The problem of waste litter is not merely visual, but it has been found that the toxicities adsorbed by the used cigarette filters leach into the environment and potentially represent a biological hazard.

In this situation, various methods for producing a biodegradable cigarette filter have been proposed. These methods include adding an additive for increasing the decomposition rate of cellulose acetate which is a biodegradable polymer, using cellulose acetate having a low degree of substitution for increasing biodegradability, or using poly-hydroxybutyrate (PHB) as a filter tow raw material, / PVB (polyvinyl butyral) and a biodegradable polymer such as starch have been proposed.

However, a satisfactory commercial solution has not yet been proposed to produce filters that are degraded fast enough to overcome the garbage problem and acceptable to consumers. The reason for this is that a method capable of simultaneously satisfying the absorption profile at the time of cigarette smoking and the improvement of the cigarette preference as a cigarette filter while achieving a sufficient biodegradation speed to solve environmental problems has not yet been achieved.

On the other hand, the lyocell fiber produced from natural pulp and amine oxide hydrate exhibits superior tensile properties and feel compared to conventional regenerated fibers. The amine oxide-based solvent used in the production of lyocell fiber can be recycled, and biodegradable The present inventors have not been able to generate any contaminants in the production process, and research on lyocell fibers has recently become more active as eco-friendly regenerated fibers.

Such a method of producing a lyocell fiber can be produced, for example, by spinning a spinning dope in which cellulose is dissolved in amine oxide (NMMO) as described in U.S. Patent Nos. 4,416,698 and 4,246,221, , Washing, drying and post-processing. In addition, the lyocell fibers are not naturally crimped and can be useful for compressing the wet fibers according to the process described in European Patent No. 797,696, or using dry steam according to the process described in EP 703,997 The crimp can be imparted by stuffer-box crimping.

However, in the case of conventional lyocell fibers, the bulgeability due to the formation of the crimp is not excellent, and most of the prior art techniques have been only for improving the physical properties such as strength improvement of the lyocell fiber. However, in order to effectively apply the lyocell fiber having the biodegradable characteristics to the cigarette filter, the cigarette filter material is required to have an excellent crimp property. In order to satisfy the requirements as the material for the cigarette filter, The research and development of the crimp improvement of the material is continuously required.

The present invention provides a lyocell material for a cigarette filter, which has biodegradation characteristics and is excellent in the number of crimps, and can sufficiently satisfy the physical properties required as a material for a cigarette filter, and a method for producing the same.

In order to solve the above-mentioned problems, a first preferred embodiment of the present invention is a method for producing a cellulose acylate composition, comprising (S1) 8 to 13% by weight of a cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine- % ≪ / RTI > of lyocell radial dope; (S2) solidifying the lyocell radiation dope radiated in the step (S1) to obtain a lyocell multifilament; (S3) washing the lyocell multifilament obtained in the step (S2); (S4) emulsifying the lyocell multifilament washed in the step (S3); And (S5) crimping the lyocell multifilament treated in the step (S4) by applying steam and pressure at a temperature of 120 to 250 ° C.

In the lyocell radiation dope of step (S1) according to the first embodiment The cellulose pulp may have an alpha-cellulose content of 85 to 99% by weight and a degree of polymerization (DPw) of 600 to 1700.

The solidification in the step (S2) according to the first embodiment may include a first solidification step by air quenching (Q / A) in which cooling air is supplied to the radiation dope and solidified; And a secondary solidification step in which the primary solidified radial dope is immersed in the coagulating liquid and solidified.

At this time, the cooling air in the primary coagulation step has a temperature of 4 to 15 ° C and a wind speed of 30 to 120 m / s, and it is preferable that the coagulating solution in the secondary coagulation step has a temperature of 30 ° C or less .

Step S5 according to the first embodiment is performed by applying pressure to the lyocell filaments in a stuffer box equipped with a press roller and an upper plate with a roller interval of 0.01 to 3.0 mm At this time, it is preferable that the pressure of the press roller is controlled to 1.5 to 4 kgf / cm 2 and the pressure of the upper plate is controlled to 0.1 to 3 kgf / cm 2.

Also, the step (S5) may be performed by applying steam having a pressure of 0.1 to 3 kgf / cm2 to the lyocell filament. In the step (S5), the steam pressure is 0.1 to 3 kgf / And a pre-treatment step of preheating and swelling the lyocell multi-filament obtained in step (S4).

(S5) according to the first embodiment may be a step of obtaining a crimped tow having 20 to 50 crimps per inch.

Meanwhile, the present invention provides a second preferred embodiment of a lyocell material for a cigarette filter having 20 to 50 crimps per inch, wherein the lyocell material is ASTM at a load of 5 cN / tex per denier The crimp stability measured by the D 3822 standard may be 50 to 80%.

According to the present invention, it is possible to provide a lyocell crimp tow which is biodegradable and has an improved number of crimps and is suitable as a material for a tobacco filter, and the performance of the filter for cigarette can be improved by applying the lyocell crimp tow of the present invention.

According to one aspect of the present invention there is provided a process for preparing a lyocell emulsion comprising (S1) 8 to 13% by weight of a cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine-Noxide (NMMO) Radiating a dope; (S2) solidifying the lyocell radiation dope radiated in the step (S1) to obtain a lyocell multifilament; (S3) washing the lyocell multifilament obtained in the step (S2); (S4) emulsifying the lyocell multifilament washed in the step (S3); And (S5) crimping the lyocell multifilament treated with the emulsion in the step (S4) by applying steam and pressure at a temperature of 120 to 250 ° C to produce a lyocell material for a cigarette filter. have.

Hereinafter, the method for producing a lyocell material for a cigarette filter of the present invention will be described in more detail.

[Step (S1)] [

In the present invention, step (S1) is a step of radiating a lyocell radial dope containing an aqueous solution of cellulose pulp and N-methylmorpholine-N-oxide (NMMO). At this time, the lyocell spinning dope contains 8 to 13% by weight of cellulose pulp; And 87 to 92% by weight of an aqueous solution of N-methylmorpholine-N-oxide, wherein the cellulose pulp has an alpha-cellulose content of 85 to 99% by weight and a degree of polymerization (DPw) of 600 to 1700 have.

If the content of the cellulose pulp is less than 8% by weight, it is difficult to realize the fiber property. If the content is more than 13% by weight, it may be difficult to dissolve in the aqueous liquid. If the content of the aqueous solution of N-methylmorpholine-N-oxide is less than 87% by weight, the solubility of the resin is undesirably increased. When the amount of the aqueous solution is more than 92% by weight, the spinning viscosity is significantly lowered, It can be difficult.

The weight ratio of N-methylmorpholine-N-oxide and water in the N-methylmorpholine-N-oxide aqueous solution may be 93: 7 to 85:15. When the weight ratio of N-methylmorpholine-N-oxide and water is more than 93: 7, the dissolution temperature is high and the cellulose may be decomposed upon dissolving cellulose. When the weight ratio is less than 85:15, And the dissolution of cellulose may be difficult.

The above-described spinning dope is used to eject it from the spinneret of the donut-shaped spinneret. At this time, the spinneret serves to discharge the spinning dope on the filament as a coagulating solution in the coagulation bath through the air gap section. The step of discharging the spinning dope from the spinneret can be carried out at 100 ° C to 110 ° C.

[Step S2]

The step (S2) of the present invention is a step of coagulating the lyocell radial dope radiated in the step (S1) to obtain a lyocell multifilament, wherein the coagulation in the step (S2) A primary coagulation step by air quenching (Q / A); And a secondary coagulation step in which the primary coagulated radial dope is immersed in the coagulating liquid to coagulate.

In the step (S1), after the spinning dope is discharged through the donut-shaped nipping, it can be passed through the air gap section of the space between the spinneret and the coagulation bath. In such an air gap section, cooling air is supplied from the air-cooled portion located inside the detachment of the donut-shaped opening to the outside from the inside of the detent, and can be primary solidified by airflow that supplies the cooling air to the radiation dope.

At this time, the factor affecting the physical properties of the lyocell multifilament obtained in the step (S2) is the temperature and the wind speed of the cooling air in the air gap section, and the solidification in the step (S2) The cooling air having a wind speed of 120 m / s may be supplied to the spinning dope to solidify.

If the temperature of the cooling air at the time of the primary solidification is less than 4 ° C, the surface of the spinneret is cooled, the cross-section of the lyocell multifilament is unevenly radiated and the spinning processability becomes poor. If the temperature is more than 15 ° C, So that the radiation fairness is not good. If the air velocity of the cooling air during the first solidification is less than 5 m / s, the primary coagulation due to the cooling air is insufficient and the yarn splice occurs. When the air velocity exceeds 60 m / s, the spinning dope discharged from the spinneret is shaken by the air, This is not good.

After the primary solidification by the air flow, the above-mentioned radiation dope is supplied to the solidification tank containing the solidification liquid, and secondary solidification can proceed. On the other hand, the temperature of the coagulating solution may be 30 DEG C or less for the progress of proper secondary coagulation. This is to ensure that the solidification rate is appropriately maintained because the secondary solidification temperature is not higher than necessary, and the solidification liquid is not particularly limited as it can be manufactured and used in a conventional composition in the technical field to which the present invention belongs.

[Step (S3)] [

In the present invention, the step (S3) is a step of washing the lyocell multifilament obtained in the step (S2). More specifically, the step of introducing the lyocell multifilament obtained in the step (S2) into a traction roller, introducing the lyocell multifilament into a water bath, and washing with water.

In the washing step of the filament, a washing solution at a temperature of 0 to 100 ° C may be used in consideration of the ease of recovery and reuse of the solvent after washing with water. Water can be used as the washing solution, May be further included.

[Step (S4)] [

In the present invention, the step (S4) is a step of tanning the lyocell multifilament washed in the step (S3), and it is preferable to carry out drying after the tanning. The emulsion treatment can be carried out with the multifilament completely immersed in the emulsion, and the quantity of the emulsion being deposited on the filament by the entrance roller and the discharge roller of the emulsion treatment apparatus is kept constant. The tanning agent serves to reduce the friction generated when the filaments are brought into contact with the drying roller, the guide, and the crimping step, and to form the fiber-to-fiber crimp. When the filament is generally used in manufacturing filaments, none.

[Step (S5)] [

(S5) is a step of applying steam and pressure to the lyocell multifilament tanned in the step (S4) and crimping the lyocell multifilament, and the crimped tow can be obtained through the step (S5) .

The term "crimp " as used throughout this specification refers primarily to imparting a wave to the filament to impart bulk sensibility of the fiber. In the present invention, the crimping process can be performed through a stuffer box having a press roller and an upper plate. When crimping according to the manufacturing method of the present invention, 20 to 50 crimps per inch Formed Crimp Tow can be obtained.

The pre-treatment step for preheating and swelling the lyocell multifilament obtained in the step (S4) through the steam box supplied with steam at a pressure of 0.1 to 3 kgf / cm 2 before the introduction of the multifilament into the stuffer box It may be more desirable to perform it first. When the multifilament is pretreated in this way, the moisture may penetrate into the filament in a short time and the modulus may be lowered. Therefore, when the multifilament is put into the stuffer box after the pretreatment step, the crimp is more smoothly given .

If the pre-treatment steam pressure is less than 0.1 kgf / cm 2, the filaments may not be completely swollen and uniform crimping may not be provided inside the stuffer box. If the pressure exceeds 3 kgf / cm 2, excessive moisture may be contained in the filaments The emulsion can not be smoothly discharged due to friction between the crimped filament and the stuffer box.

The pretreated filaments can then be injected into the stuffer box for crimp application. At this time, it is preferable that the steam pressure supplied to the inside of the stuffer box is controlled to be 0.1 to 3 kgf / cm 2, the press roller pressure to 1.5 to 4 kgf / cm 2, and the upper plate pressure to 0.1 to 3 kgf / cm 2. The steam pressure can be controlled by the auto control method. If the pressure is less than 0.1kgf / ㎠, the crimp is not formed smoothly. If the pressure exceeds 3kgf / ㎠, the pressure inside the stuffer box is raised due to an excessive amount of steam. Which may result in nonuniform crimp formation or failure to maintain uniformity of shape after crimping.

When the pressure is less than 1.0 kgf / cm < 2 >, the desired crimp number is not formed due to the change in the thickness of the fine tow. If it is more than 4 kgf / cm 2, the pressing force is too strong, so that the content of moisture or oil present in the tow is rapidly lowered, and the filament may not pass through the stopper box.

The interval of the press rollers is preferably maintained at 0.01 to 3.0 mm. If the distance between the press rollers is less than 0.01 mm, the pressure of the filament due to the roller becomes high and the crimp can not be formed or damage may occur due to the surface friction of the filament after formation. If the distance is more than 3.0 mm, So that uniform crimp formation may be difficult.

Further, the upper plate functions to move the filament passing through the press roller up and down to impart a uniform crimp. In the present invention, when the pressure of the upper plate is less than 0.1 kgf / cm2, the tow may stay in the stuffer box for a long time If the pressure exceeds 3 kgf / cm 2, the steam can not be discharged smoothly in the stopper box and the crimp shape may become irregular.

Above all, in the present invention, it is desirable to maintain the internal temperature of the stuffer box at a high temperature of 120 to 250 ° C, more preferably 140 to 240 ° C, in order to further improve the morphological stability of the crimped tow It can be more important than. Generally, the higher the steam pressure, the higher the temperature. Therefore, the internal temperature of the stuffer box can be controlled by the steam pressure. However, in the present invention, it is preferable that the steam pressure is limited to 3 kgf / On the assumption that heat loss does not occur, the temperature can only rise to a maximum of 143 ° C.

Therefore, in order to improve the internal temperature of the stuffer box, it is preferable to use a separate superheated steam generator. The temperature inside the stuffer box is 120 ° C , It is not preferable because the shape stability effect is insufficient and the crimp shape can not be maintained in the filter manufacturing process. If the temperature exceeds 250 ° C, the concentration of the oil in the stuffer box becomes high, It is not good because.

As a result, the lyocell crimping tow manufactured according to the manufacturing method of the present invention can secure and maintain a crimp of 20 / inch or more, more preferably 20 to 50 / inch, so that a filter having a diameter of 16.5 mm to 24.5 mm When formed as a filter road, as measured by KS H ISO 6565 And may exhibit an aspiration resistance of about 185 to 620 mm H ₂ O.

In addition, since the crimp stability measured by the ASTM D 3822 standard is 50 to 80% at a load of 5 cN / tex per denier, The crimp shape stability in the rod can be maintained even after the filter process in which high tension is given.

Further, when the lyocell crimping tow of the present invention is made of a cigarette filter, it satisfies the required physical properties such as a suction resistance, a filter hardness and a filter removing ability, and can maximize its effect.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto.

Example  One

A cellulose pulp having a degree of polymerization (DPw) of 820 and an alpha-cellulose content of 93.9% was mixed with an NMMO / H20 mixed solvent (weight ratio 90/10) having a propyl gallate content of 0.01% by weight to prepare a radiation dope for producing a lyocell material having a concentration of 12% . First, the spinning dope was maintained at a spinning temperature of 110 캜 in a spinning nozzle of a donut-type spinneret, and the spinning dope was controlled by controlling the discharge amount and spinning speed so that the fineness of the filament was 3.0 denier.

The spinning dope on the filament discharged from the spinning nozzle was supplied to the coagulating solution in the coagulation bath through the air gap section. At this time, the cooling air in the air gap section is subjected to primary solidification of the spinning dope at a temperature of 8 캜 and a wind speed of 50 m / s. The coagulating solution used was one with a temperature of 25 ° C and a concentration of 85% by weight of water and 15% by weight of NMMO. At this time, the concentration of the coagulating solution was continuously monitored using a sensor and an refractometer.

The filaments elongated in the air layer through the traction roller were washed with a washing solution sprayed in a water washing device to remove the remaining NMMO. The filaments were soaked in the filaments sufficiently homogeneously and squeezed again so that the filament had an emulsion content of 0.2% Lt; RTI ID = 0.0 > 150 C. < / RTI > Then, the dried lyocell multi-filament was preheated and swelled while passing through a steam box at a steam pressure of 0.5 kgf / cm 2, and crimped in a stuffer box to obtain a lyocell crimped tow. At this time, the temperature inside the stuffer box was set to 180 ° C using a superheated steam generator, steam pressure was 1.0 kgf / cm 2, press roller pressure and spacing were 3.0 kgf / cm 2 and 0.1 mm, kgf / cm < 2 >.

Example  2

The same procedure as in Example 1 was carried out except that the temperature inside the stuffer box was set to 160 ° C and the steam pressure to 0.5 kgf / cm 2 when the crimp tow was obtained by crimping in the stuffer box. .

Example  3

The same procedure as in Example 1 was carried out except that the temperature inside the stuffer box was set to 140 ° C and the steam pressure was set to 1.0 kgf / cm 2 when the crimp tow was obtained by crimping in the stuffer box. .

Example  4

The same procedure as in Example 1 was carried out except that the temperature inside the stuffer box was set to 200 ° C and the steam pressure to 2.0 kgf / cm 2 when the crimp tow was obtained by crimping in the stuffer box. .

Comparative Example  One

Except that in the case of obtaining a crimped tow by crimping in a stuffer box, the temperature inside the stuffer box was controlled at 100 캜 and the steam pressure at 0.5 kgf / cm 2 without using a superheated steam generator, 1, a lyocell material for a cigarette filter was prepared.

Comparative Example  2

When the crimper tow is obtained by crimping in the stuffer box, the temperature inside the stuffer box is 110 ° C And the steam pressure was set to 1.0 kgf / cm 2, a lyocell material for a cigarette filter was prepared in the same manner as in Example 1.

Comparative Example  3

The same procedure as in Example 1 was carried out except that the temperature inside the stuffer box was set to 260 ° C using a superheated steam generator and the steam pressure was set to 4.0kgf / cm 2 when the crimped tow was obtained by crimping in a stuffer box To produce a cigarette filter lyocell material.

Measurement example

(1) Crimp count measurement: Measured according to KS K 0326 standard. After taking 20-sample samples of which the crimp was not damaged, prepare a glossy paper (space distance 25 mm) prepared beforehand with a 4-5% celluloid amyl acetate adhesive (25 ± 5)% for each attachment length, and then leave the adhesive to dry. The sample was subjected to a crimp test machine to obtain a crimp number of 25 mm between 1 and 100 denier per 1D per 1D (= 2 mgf). Table 1 shows the average value up to one decimal place.

(2) Crimp Stability Measurement: Measured according to ASTM D 3822 standard using Favimet + analyzer. The 30-sample sample without crimp damage was taken and the SS Curve results were analyzed by applying a load of 5cN / tex per 1D (Pulling the sampled yarn until the crimp is gone, reducing the length to the initial setting, and then measuring the degree of stretching when pulled again). In the following equation, extension 1 is a first elongation and extension 2 is a second elongation.

<Formula 1>

(3) Measurement of Aspiration Resistance: Filter rods for tobacco filters having uniform diameters were prepared using the crimped tows prepared in the above examples and comparative examples, and a filter rod for a tobacco filter was prepared using a suction resistance meter according to KS H ISO 6565 And the star attraction resistance was measured.

Temperature in the stuffer box
(° C) Steam
pressure
(kgf / cm2) Press
Roller pressure
(kgf / cm2) plate
pressure
(kgf / cm2) Crimp
Count
(Dogs / inch) Crimp state Crimp Stability
(%) absorption
resistance
(mmH ₂ O) Example 1 180 One 3 1.5 36 Good 63 320 Example 2 160 0.5 3 1.5 35 Good 57 300 Example 3 140 One 3 1.5 35 Good 51 280 Example 4 200 2 3 1.5 38 Good 66 340 Comparative Example 1 100 0.5 3 1.5 35 Good 43 240 Comparative Example 2 110 One 3 1.5 36 Good 46 250 Comparative Example 3 260 4 3 1.5 Measurement X Bad Measurement X Measurement X

As a result of the physical property measurement, as shown in Table 1, the number of crimps in Examples 1 to 4 and Comparative Examples 1 and 2 except for Comparative Example 3 was more than 30 / inch, and as a result of visual confirmation, Were also found to be good on average. However, in Comparative Examples 1 and 2, in which the temperature in the stator box was lower than that in the Examples, the crimp stability was less than 50%, and the crimp stability was not excellent, and as a result, it was confirmed that the suction resistance in the filter was lowered. In Examples 1 to 4 having excellent crimp stability, the shape of the crimp could be maintained even though the filter manufacturing process for imparting a high tension to tow was performed. In Comparative Examples 1 and 2, however, , And it was interpreted that the crimp shape could not be maintained.

On the other hand, in the case of Comparative Example 3 in which the temperature in the stuffer box was set to an extreme condition, the steam pressure in the stuffer box became excessively high, so that the discharge pressure of the Tow during the crimp formation could not be controlled uniformly. As a result, It can not be secured. That is, even when the temperature in the stuffer box is too high beyond the range of the present invention, a tow having a good crimp can not be manufactured, which makes it difficult to apply it to a cigarette filter.

Claims (9)

(S1) spinning a lyocell spinning dope containing 8 to 13% by weight of cellulose pulp and 87 to 92% by weight of an aqueous solution of N-methylmorpholine-Noxide (NMMO);
(S2) solidifying the lyocell radiation dope radiated in the step (S1) to obtain a lyocell multifilament;
(S3) washing the lyocell multifilament obtained in the step (S2);
(S4) emulsifying the lyocell multifilament washed in the step (S3); And
(S5) crimping the lyocell multifilament treated in the step (S4) by applying steam and pressure at a temperature of 120 to 250 ° C.
The method according to claim 1, wherein the cellulose pulp in the lyocell spinning dope of step (S1) has an alpha-cellulose content of 85 to 99% by weight and a degree of polymerization (DPw) of 600 to 1,700. Method of manufacturing a material.
The method of claim 1, wherein the solidification in step (S2) comprises: a first solidification step by air quenching (Q / A) for supplying cooling air to the radiation dope; And a second solidification step of immersing the first solidified radioactive dope in the coagulating liquid.
The method according to claim 3, wherein the cooling air in the primary solidification step has a temperature of 4 to 15 캜 and a wind speed of 30 to 120 m / s, and the coagulating solution in the secondary solidification step has a temperature of 30 캜 or lower Characterized in that it comprises the steps of:
The method as claimed in claim 1, wherein the step (S5) is performed by applying pressure to the lyocell filaments in a stuffer box having a press roller and an upper plate with a roller interval of 0.01 to 3.0 mm Lt; / RTI &
Wherein the pressure of the press roller provided in the stuffer box is controlled to be 1.5 to 4 kgf / cm 2 and the pressure of the upper plate is controlled to be 0.1 to 3 kgf / cm 2.
[6] The method of claim 1, wherein the step (S5) is performed by applying steam having a pressure of 0.1 to 3 kgf / cm2 to the lyocell filaments.
The method according to claim 1, further comprising a pretreatment step for preheating and swelling the lyocell multi-filament obtained in step (S4) with a steam pressure of 0.1 to 3 kgf / Characterized in that it comprises the steps of:
The method of claim 1, wherein the step (S5) is a step of obtaining a crimped tow having 20 to 50 crimps per inch.
There are 20 to 50 crimps per inch,
A lyocell material for a cigarette filter having a crimp stability of 50 to 80% as measured according to ASTM D 3822 under a load of 5 cN / tex per denier.