KR20070100481A - Spinning die for lyocell fibers, and method for preparation of lyocell fibers by using the same - Google Patents

Abstract

A spinning die for lyocell fibers and a method for manufacturing the lyocell fibers using the same are provided to prevent nozzles from being polluted during a dry and wet spinning process of the lyocell fibers. A spinning die(1) comprises a spinning die body(11) having at least one nozzle openings(12) for transferring lyocell spinning dope, and at least one pin type spinning nozzles(13) connected to the nozzle openings. The pin type spinning nozzles are positioned on a bottom surface of the spinning die body. The pin type spinning nozzles have lengths of 0.1-10 mm from the bottom surface of the spinning die body. The pin type spinning nozzle has an inner diameter of 0.05-0.5 mm.

Description

Spinnery for lyocell fibers, and method for producing lyocell fibers using the same {SPINNING DIE FOR LYOCELL FIBERS, AND METHOD FOR PREPARATION OF LYOCELL FIBERS BY USING THE SAME}

1 is a perspective view showing an example of the spinneret of the present invention.

Figure 2 is a cross-sectional view showing an example of a spin type spinneret of the spinneret of the present invention.

[Industrial use]

The present invention relates to a spinneret for lyocell fibers, and a method for manufacturing lyocell fibers using the same. More particularly, the processability of the fiber manufacturing process is prevented by preventing adhesion of the surface of the cap in the initial discharge and stabilizing spinning operations. It relates to a spinneret for lyocell fibers, and a method for producing lyocell fibers using the same.

[Private Technology]

In general, the spinning method of synthetic fibers is divided into melt spinning and solution spinning.

Melt spinning proceeds to a process in which the polymer material is melted by heat and passed through a mold in a state of fluidity to form a fiber, and is blown by cooling air to uniformly cool / solidify.

Solution spinning is a process used for spinning a polymer material that is difficult to melt due to heat, and is further divided into wet spinning and dry spinning.

The difference between dry spinning and wet spinning is the same process for preparing spinning stock solution by dissolving the polymer in a solvent, but wet spinning is the process of spinning up spinning stock solution from the spinneret to the coagulation bath to solidify / solidify. The spinning proceeds to a process of discharging the spinning solution into hot air without a coagulation bath and evaporating the solvent to solidify it.

In the case of melt spinning, stretching can be performed in a state of plasticity by heat, in the case of dry spinning among solution spinning, stretching is performed while the solvent is evaporated, and in the case of wet spinning, the solidification process depends on the concentration and temperature of the coagulation bath. Stretching is possible.

The spinning methods are widely used in synthetic fibers which are currently developed and marketed as general spinning methods. Spinning methods are being developed that combine these spinning methods, such as wet and dry spinning.

Wet and dry spinning takes the form of both dry spinning and wet spinning. The spinning solution is discharged from the air in the air, passes through the airbag section between the spinneret and the coagulation bath, and enters the coagulation bath. This is a spinning method in which a solvent is desolvated and coagulated by a non-solvent. In other words, the ejection from the spinneret is carried out by a dry method, and the solvent extraction is carried out by a wet method.

The method for preparing lyocell fibers is to prepare a spinning stock solution consisting of three components of cellulose / N-methylmorpholine N-oxide (NMMO) / water, and then spin it. The wet spinning method includes non-solvent water. According to the spinning occurs very fast coagulation action is difficult to secure the stretching performance and physical properties. In addition, since NMMO of the spinning stock solution is a salt compound, it is difficult to evaporate the solvent only by dry spinning.

Therefore, in order to manufacture the lyocell fibers, the wet and dry spinning method in which dry spinning and wet spinning methods are properly combined is most suitable, and in this process, the air layer, which is an air layer existing between the spinneret and the coagulation bath, is maximally utilized. Therefore, improvement of physical properties and radioactivity is essential.

However, in the air of the general lyocell spinning process, the problem of contaminating the spinneret due to the viscosity of the lyocell spinning stock solution itself occurs frequently. As a result, cutting of the filament yarn occurs frequently, so that the spinning operation is frequently stopped, and once the spinneret is contaminated, the wiping of the filament is not easy and the productivity is seriously lowered.

Especially when using spinnerets of metal materials, this problem is more serious.

The present invention is to solve the above problems, the object of the present invention is to reduce the contamination of the spinneret, for the lyocell fiber comprising a fin-type spinning nozzle to ensure a uniform quality of the filament fiber produced To provide radiation detention.

Another object of the present invention to provide a method for producing a lyocell fiber using the spinneret.

In order to achieve the above object, the present invention, the spinneret body formed with at least one nozzle opening for the delivery of lyocell spinning dope; And a spinneret for lyocell fibers located on a bottom surface of the spinneret body and including at least one pin-type spinneret connected to the nozzle opening.

The present invention also comprises the steps of dissolving cellulose in a mixed solvent of N-methylmorpholine-N-oxide (NMMO) and water to prepare a spinning stock solution; And spinning the lyocell fibers from the spinning stock solution using the spinneret equipped with the spinneret.

Hereinafter, the present invention will be described in more detail.

In order to produce lyocell fibers by wet-wet spinning, the spinning performance by the cool airflow in the air conditioner is the most important part. However, it must first be prevented from contaminating the spinneret with the lyocell spinning stock solution.

The present inventors use a pin-type spinneret having a spinneret protruding downward from the spinneret's surface, thereby preventing the lyocell spinning stock from sticking to the spinneret's surface and contaminating it, without requiring a separate wiping for 100 hours. It was found out that the lyocell fiber can be produced continuously without trimming, and thus, the present invention was completed.

1 is a plan view showing an example of the spinneret of the present invention. Referring to FIG. 1, the spinneret for lyocell fibers 1 of the present invention comprises a spinneret body 11 having at least one nozzle opening 12 for delivery of a lyocell spinneret; And at least one pin-type spinning nozzle 13 positioned on the bottom surface 11b of the spinning collar main body and connected to the nozzle opening 12.

The number of the fin-type spinning nozzles may be appropriately selected according to the number of the filaments to be spun, but is not particularly limited. Preferably, 500 to 2000 fin-type spinning nozzles may be included in one spinneret. In addition, the spinneret is preferably arranged in a donut shape while maintaining an equal distance from each other.

2 is a cross-sectional view showing an example of a pin-type spinning nozzle of the spinneret 1 of the present invention. The pin-type spinning nozzle may be attached to the bottom surface of the spinneret main body by welding or the like, but may be attached in the form of a pin-type spinning nozzle 13 inserted into the nozzle opening 12 as shown in FIG. 2. have.

In the spinneret of the present invention, the inner diameter (D) of the fin type spinning nozzle can be determined according to the fineness of the fiber to be spun, the viscosity of the spinning solution, and the like, and can be selected within a conventional range. It is not specifically limited. However, in spinning of lyocell fibers, the inner diameter of the fin type spinning nozzle is preferably 0.05 to 0.5 mm, more preferably 0.09 to 0.25 mm.

The height H of the fin-type spinning nozzle should be 0.1 mm or more, preferably 0.5 mm or more, from the bottom surface 11b of the spinneret main body to prevent contamination of the spinneret surface and to prevent trimming. For smooth spinning it is preferred to have a length of 10 mm or less, more preferably 2 mm or less.

Further, in the spinneret of the present invention, in order to ensure sufficient spinning nozzle pressure and to maintain the discharge amount uniformly, the length / diameter ratio (L / D) is a ratio of the flow path length and the diameter of the spinneret formed inside the spinneret. ) Is preferably 2.5 or more, and is preferably 50 or less, more preferably 20 or less, in order to prevent the spinning pressure inside the spinneret from excessively rising.

The spinneret of the present invention may be applied to the spinning of lyocell fibers, and in particular to the wet and dry spinning method of lyocell fibers.

Method for producing a lyocell fiber of the present invention using the spinneret is as follows. In the method for producing lyocell fibers of the present invention, cellulose is dissolved in a mixed solvent of N-methylmorpholine-N-oxide (NMMO) and water to prepare a spinning stock solution, and the spinneret is equipped with the spinneret of the present invention. Spinning the lyocell fibers from the spinning stock solution.

At this time, the spinning stock solution may be prepared according to a conventional method, but is not particularly limited, but a mixed solvent containing N-methylmorpholine-N-oxide (NMMO) and water in a weight ratio of 93: 7 to 85:15 It is preferable to dissolve the cellulose in 7 to 18% by weight.

The viscosity of the spinning stock solution is preferably maintained for 8000 to 25000 Poise for smooth spinning.

The spinning process using the spinning stock solution may be carried out according to a conventional wet and dry method except for mounting the spinning cap of the present invention, and preferably spinning the spinning stock solution at a temperature ranging from 80 to 130 ° C. Air gab section for supplying cooling air to the uncoagulated fiber, coagulation liquid section for coagulating cooled uncoagulated fiber, and water washing to remove residual N-methylmorpholine-N-oxide (NMMO) from the coagulated fiber. After passing the section, and the drying section, it is preferable to include the step of winding up.

The method for producing a lyocell fiber of the present invention can produce a high-strength lyocell fiber having a tensile strength of 5 g / d or more, single thread fineness variation of 2% or less, such a lyocell fiber material such as tire cord material It can be used as industrial fiber.

Hereinafter, preferred embodiments of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

Example 1

A pulp with a degree of polymerization (DPw) of 1,200 and 97% of α-cellulose is mixed with a NMMO / H ₂ 0 mixed solvent (weight ratio 90/10) having a propylgallate content of 0.01% by weight, to prepare a cellulose solution having a concentration of 11% by weight. Prepared.

The cellulose solution was spun through a spinneret including a pin-type spinning nozzle as shown in FIG.

At this time, the pin-type spinning nozzle is 0.2 mm inner diameter (D), nozzle height (H) 1 mm from the bottom surface of the spinneret main body, length / diameter ratio (L / D) of the spinning nozzle 10, number of spinning nozzles 1000 Personal spinnery was used.

The spinning temperature of the spinning nozzle was maintained at 110 ° C, and the spinning amount and spinning speed were adjusted so that the final filament fineness was 1,500 denier.

The uncoagulated fiber discharged from the spinning nozzle passes through the air layer (or air gap) having a distance of 50 mm, and then passes through the coagulating liquid. In the air layer, the temperature / humidity is 10 at the cooling air supply unit installed at the front of the spinning nozzle. Cooling air at < RTI ID = 0.0 > C / 75% RH < / RTI >

In addition, the coagulation liquid was adjusted to maintain the temperature of 20 ℃, the concentration of 85% by weight of water, 15% by weight of NMMO to circulate the coagulation liquid of the upper coagulation bath and lower coagulation bath.

At this time, the coagulating liquid concentration of the cooling air and the coagulation bath in the air layer was continuously monitored using a sensor and a refractometer.

The remaining NMMO of the filament leaving the coagulation bath was removed by washing with water, and dried and wound up to prepare a lyocell filament yarn.

Example 2

The pin-type spinning nozzle was the same as in Example 1 except that a spinneret having an inner diameter (D) of 0.3 mm, a nozzle height (H) of 0.5 mm from the bottom surface, and a spinneret length / diameter ratio (L / D) of 5 was used. The procedure was repeated to prepare lyocell filament yarn.

Comparative Example 1

The same procedure as in Example 1 was repeated except that the spinneret had a diameter of 0.2 mm, a length / diameter ratio (L / D) of 10, and a normal spinneret without a pin-type spinneret was used. Was prepared.

Comparative Example 2

The same procedure as in Example 1 was repeated except that the spinneret had a diameter of 0.3 mm, a length / diameter ratio (L / D) of 5, and a normal spinneret without a pin-type spinneret was used. Was prepared.

The physical properties of the spinning stock solution, filament yarn prepared according to Examples 1 and 2, and Comparative Examples 1 and 2 were evaluated in the following manner.

 (a) strength (g / d) and elongation (%)

The test piece was dried at 110 ° C. for 2 hours, preliminarily dried below the process moisture content, and then left to stand for at least 24 hours in a standard state of KSK 0901 (fiber test room standard state) to reach a water equilibrium state.

The prepared test piece was measured in accordance with the KSK 0412 standard at 250 mm of sample length and 300 m / min of tensile velocity by giving eight twists per 10 cm using an Instron low speed tensile tester.

(b) Uniformity (U%)

As the rate of change of the weight (or cross-sectional area) per unit length of the filament yarn, Keishiki Co., Ltd. was also measured using a tester.

(c) Cutting strength and elongation at break (CV%)

The test piece of Example 1 and the test piece of Comparative Example 1 were performed 10 times in the same manner, and the results were measured as standard deviations. The variation rate (CV%) was calculated according to the following Formula 1.

[Calculation 1]

Rate of Change (CV%) = (Standard Deviation / Average) × 100

(d) radiation stability

Radiation stability was determined according to the criteria of Table 1 below by observing the number of trimmings per 1000 spinning nozzles of the spinneret used at 100 mpm of winding conditions given the spinning condition traction rate (V1).

TABLE 1

Radio Stability Rating S A B F Thread Trimming Count (X) 0 0 <X ≤ 5 5 <X ≤ 10 10 <X

Yarn properties measured according to the above method are summarized in Table 2 below.

TABLE 2

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Radiation stability S S B F Cutting strength (g / d) 6.8 7.2 6.3 6.7 Change in cutting strength (CV%) 2.5 2.8 4.2 6.3 Elongation at break (%) 6.0 5.2 5.9 4.8 Elongation at Break (CV%) 4.8 5.2 5.4 5.7 Uniformity (U%) 1.63 1.85 3.40 4.47

As shown in Table 2, the lyocell fiber prepared using the spinneret of the present invention has superior spinning stability, cutting strength, and cutting force compared to the lyocell fibers of Comparative Examples 1 and 2, which are manufactured using a general spinneret. The change in cutting elongation is small, and the uniformity is low due to the low uniformity.

The spinneret of the present invention has the advantage of improving the fairness of the fiber manufacturing process by preventing nozzle contamination generated in the wet and dry spinning process of the lyocell fiber, the fiber produced using the spinneret of the present invention is uniform quality Has

Claims (7)

A spinneret body having at least one nozzle opening for delivery of lyocell spinning dope; And At least one pin-type spinning nozzle located on the bottom surface of the spinneret main body and connected to the nozzle opening Spinning detention for lyocell fibers comprising a. The method of claim 1, The pin-type spinning nozzle has a spinneret for lyocell fibers having a pin length of 0.1 to 10 mm from the bottom surface of the spinneret main body. The method of claim 1, Spinneret for lyocell fibers having an inner diameter of the pin-type spinning nozzle is 0.05 to 0.5 mm. The method of claim 1, Spinneret for lyocell fibers of the length / diameter ratio (L / D) of the pin-type spinning nozzle is 2.5 to 50. Preparing a spinning stock solution by dissolving cellulose in a mixed solvent of N-methylmorpholine-N-oxide (NMMO) and water; And Spinning the lyocell fibers from the spinning stock solution using the spinning apparatus equipped with the spinneret according to any one of claims 1 to 4. Method for producing a lyocell fiber comprising a. The method of claim 5, The spinning stock solution is prepared by dissolving cellulose in a mixed solvent containing N-methylmorpholine-N-oxide (NMMO) and water in a weight ratio of 93: 7 to 85:15 by 7 to 18% by weight. Method of preparation. The method of claim 5, The spinning of the lyocell fiber may include an air gab section for supplying cooling air to the spun uncoagulated fiber, a coagulating solution section for solidifying the cooled uncoagulated fiber, and the remaining N-methylmorpholine- from the coagulated fiber. Method for spinning a lyocell fiber comprising the step of winding after passing through the washing section, and the drying section to remove N-oxide (NMMO).

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