KR20110073979A - Method of process for cellulose multi-filament - Google Patents

Abstract

PURPOSE: A method for preparing cellulose multifilament is provided to ensure proper strength to lyocell multifilament. CONSTITUTION: A method for preparing cellulose multifilament comprises: a step of mixing liquid concentrate N-methylmorpholine N-oxide solution and cellulose powder for a swelling and homogenized cellulose solution; a step of extruding/spinning the cellulose solution through a spinning nozzle in an angle(alpha) of 65-85 degrees between the nozzle surface and outermost single yarn; a step of passing the yarn through an air layer; and a step of solidifying, washing, and drying.

Description

Method of manufacturing cellulose multifilament {Method of process for cellulose multi-filament}

The present invention relates to a method for producing cellulose multifilament.

Lyocell, a cellulose fiber, has various inherent properties, and in particular, has excellent mechanical properties and thermal stability than other fibers, and is a very suitable fiber as a material in a field requiring form stability. Based on these characteristics, it is used as various industrial reinforcement materials. Especially in the manufacturing field of tires, belts, hoses, etc., dimensional stability and thermal stability from the design stage have an important influence on the performance of the product. In view of this, lyocell multifilament requires various properties as a reinforcing material depending on the type and application of the applied product. In particular, the required physical properties of the reinforcement of lyocell fibers with excellent thermal stability can be represented by modulus and elongation at break, which are related to morphological stability and fatigue resistance in addition to the strength of the yarn. The range of is determined.

In addition, lyocell filament has excellent touch, gloss, dyeing and drape properties of cellulose fibers, and unlike rayon fibers, it has low strength and modulus due to moisture absorption, and thus has excellent washing fastness and weather resistance. And unlike the manufacturing method of rayon that causes environmental pollutants such as CS ₂ , H ₂ S is manufactured by an environmentally friendly method that recovers and reuses the entire amount of NMMO, a solvent used. Many of these methods have been proposed, starting with US Pat. No. 3,447,939. As a method of changing the properties of the lyocell filament manufacturing process, several methods can be considered in the yarn manufacturing step, and the yarn properties according to the degree of orientation of the raw material pulp by the degree of polymerization and the degree of orientation by spinning Changes in physical properties, changes in physical properties due to solidification conditions, changes in yarn properties realized by changes in crystal structure due to yarn temperature and tension in the process after spinning, and changes in properties due to the addition of additives have. International Patent WO10-0395278 illustrates yarn property values according to tension conditions in each step of a process after spinning of lyocell filaments, and it can be seen that yarn property values vary greatly depending on conditions. However, the method of the present invention focuses on controlling the mechanical properties and fibril generation of cellulose fibers by adjusting the angle α between the nozzle face and the outermost single yarn not mentioned above. The angle at which the single yarn meets the surface of the coagulation bath changes according to the angle (α) of the nozzle surface and the outermost single yarn, which causes the shaking of the surface of the coagulation bath and the change in the tension of the single yarn. It will affect the production of brill. In the present invention, in order to adjust the angle (α) of the nozzle surface and the outermost single yarn to change the length of the coagulation bath to improve the mechanical properties, fibrillation resistance and uniformity of the cellulose fiber.

The lyocell filament manufacturing process is a dry and wet spinning process, which is produced by solidification, washing, drying, emulsion, and winding after the spinning process. In particular, most of the stretching is performed during the solidification process, thereby having a significant influence on the degree of orientation of the final fiber obtained. In addition, during the coagulation process, the surface of the coagulation bath is shaken when the spinning speed is 50 m / min or more. Such a phenomenon becomes a factor that impairs process stability. Since the shaking of the surface of the coagulation bath is greatly influenced by the coagulation bath input angles of the single yarns discharged from the nozzle, in the present invention, the angle (α) between the nozzle face and the outermost single yarn is adjusted to adjust the overall mechanical properties, fibrillation, and fineness. It is intended to be able to produce improved cellulose fibers.

In order to achieve the above object, the present invention comprises the steps of: (A) preparing a liquid concentrated N-methylmorpholine N-oxide (NMMO) solution and cellulose powder into a swelled and homogenized cellulose solution; (B) extruding the cellulose solution such that the angle between the nozzle face and the outermost single yarn is 65 to 85 degrees through a spinning nozzle having an orifice number of 300 to 1,500; (C) it provides a method for producing a cellulose multifilament comprising the step of passing the extruded spun yarn through an air layer to reach a coagulation bath, followed by coagulation and washing with water.

The cellulose fiber prepared according to the present invention had high strength and fibrill resistance suitable for lyocell multifilament by adjusting the angle between the nozzle face and the outermost single yarn at 65 degrees to 85 degrees. These yarns relate to cellulose fibers excellent in dimensional stability and at the same time improved fatigue resistance, and a method for producing the same. The cellulose fibers prepared according to the present invention have high strength and high fibril resistance.

According to a suitable embodiment of the present invention, in the method for producing cellulose fiber, (A) preparing a liquid concentrated N-methylmorpholine N-oxide (NMMO) solution and cellulose powder into a swelled and homogenized cellulose solution ; (B) extruding the cellulose solution such that the angle between the nozzle face and the outermost single yarn is 65 to 85 degrees through a spinning nozzle having an orifice number of 300 to 1,500; (C) providing a method for producing a cellulose multifilament improved mechanical properties and fibrillation resistance comprising the step of passing the extruded spun yarn through an air layer to reach a coagulation bath, followed by coagulation and washing with water do.

According to another suitable embodiment of the present invention, in the step (B), the outer diameter of the spinning nozzle is 90mm to 150mm, and the length of the coagulation bath is adjusted to 80mm to 400mm provides a method for producing a cellulose multifilament do.

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

The multifilament is drawn and oriented according to the ratio between the ejection speed and the spinning speed of the nozzle during the solidification process, which means a change in tension of each single yarn, which is a change in the mechanical properties of the filament. . In addition, if the spinning speed is more than 50m / min, the shaking of the surface of the coagulation bath becomes large, affecting the fibrillation of the single yarn. In the present invention, it is noted that the process of discharging from the nozzle and obtaining the coagulation bath has a great influence on the mechanical properties of the final product, and to solve this problem, the angle (α) between the nozzle surface and the outermost single yarn is adjusted. As a result, a product having improved physical properties, fibril resistance and fineness of filament yarn was obtained.

The present invention provides a method for producing a lyocell multifilament having a single yarn fineness in the range of 0.5 to 3.0 denier, and a cellulose NMMO solution coming out through a nozzle having an outer diameter of 90 mm to 150 mm and a hole number of 300 to 1500 is applied to a coagulation bath through a cold air layer. It is related with the manufacturing method of the cellulose fiber formed into a bundle, and passing through a coagulation | solidification, water washing, and a drying process. To improve the physical properties of the cellulose fiber manufactured by adjusting the angle (α) between the nozzle face and the outermost single yarn in 65 to 85 degrees in detail as a virtual triangle of the nozzle face and several single yarns and a bundle of bundles in one bundle. It relates to a method for producing a cellulose fiber for.

In the present invention, two factors are introduced to adjust the angle α between the nozzle surface and the outermost single yarn, which is the outer diameter of the nozzle and the length of the coagulation bath. The nozzle face is the base, the outermost single yarn is the slope, and the straight distance from the center of the nozzle face to the area where it is gathered into one bundle is high. The outer diameter of the nozzle is 90 mm to 150 mm, preferably 100 mm to 120 mm, and the length of the coagulation bath is 80 mm to 400 mm, preferably 150 mm to 250 mm. The distance between the nozzle and the surface of the coagulation bath is 70mm and this section becomes the air layer where the cooling wind enters. As the angle α between the nozzle face and the outermost single yarn becomes smaller, the tension difference between the single yarn in the center of the nozzle and the outermost single yarn increases, which leads to a decrease in physical properties of the final filament. In addition, the angle of getting the outermost single yarn to the surface of the coagulation bath is increased, so that the area where the surface of the coagulation bath collides with the surface of the single yarn is widened, and the fibril generation is rich. However, as the angle α between the nozzle face and the outermost single yarn increases, the length of the coagulation bath increases, which may be related to the problem of the radiation space and the capital investment cost, which may cause other problems. Therefore, it is very important to determine the angle α between the optimum nozzle surface and the outermost single yarn.

Hereinafter, the configuration and effects of the present invention will be described in more detail with specific examples, but the examples are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention. Physical properties of the filament in the Example was evaluated in the following manner.

Property evaluation method

(a) Strength (g / d), Elongation at break (%), Modulus of elasticity (g / d) and Intermediate elongation (%) of multifilament

Immediately after drying for 2 hours at 107 ℃ in a hot air dryer. Instron (Instron 4465) was used for the measurement. In this case, the measurement conditions of the yarn were added to the twist of 80 Tpm (80 twist / m) and then 250 mm of sample length and tensile speed. It measured by 300 mm / min. Modulus of elasticity is expressed as the slope of the load to produce a certain level of elongation, and refers to the slope of the elongation-load curve in the elongation test. Elongation at specific load represents the elongation at the point of 4.5 kg (for 1500 denier of filament) or 6.8 kg (for 2000 denier of filament), the lower the elongation, the higher the elastic modulus and the deformation of the filament This is less.

(b) Fibril index

The cellulose fiber prepared in the present invention was evaluated for the fibrillation index (F.I.) using the following method. 10 force 5 mm stainless metal balls with 50 10 mm length multifilaments in a 250 ml Erlenmeyer Flask (narrow neck) containing 25 ° C water to force fibrils. It was rotated for 30 minutes at 10 rpm using a magnetic stirrer (magnetic bar 40L × 10mmφ) and dried to evaluate the fibrillation index (FI) through an optical microscope.

Samples of the fibers were arranged according to the increase in fibrillation.

From each sample, the reference fiber length is measured, the number of fibrils according to the reference field is counted, the length of each fibrils is measured, the average fibrillation length is calculated, and the value obtained by multiplying the number of fibrils is determined for each fiber. It was.

The fiber showing the highest value is the most fibrillated fiber, the fibrillation index is set to an arbitrary value as a reference, and the fibrillation index is set to 0 for the fibers that are not fibrillated as a whole. The remaining fibers were arranged in a range of 1 to 10 by setting appropriate values according to the degree of fibrillation.

(c) Method of measuring uniformity (U%)

After standing at 20 ° C for 65 hours at 65% RH for more than 24 hours, use a measuring device of Keisokki's model name KET 80III / C to give a twist of S type while giving a slot of S type. ) Was measured at 50 m / min for 2 minutes 30 seconds.

Example

[Example 1]

Powdered NMMO was prepared by pulverizing Buckeye's pulp (V-81) having a degree of polymerization (DPw) of 1,200 to 300 µm or less, and then continuously forced into the twin screw extruder using a side feeder for pulp supply. Supplied. The cellulose solution prepared by the above method was spun at a speed of 110 m / min.

In the spinning process, the number of orifices (orifices) of the spinning nozzle was 900, and the ratio of the orifice diameter and length (L / D) was discharged through the air layer having a length of 70 mm from the spinning nozzle having a diameter of 6 and an outer diameter of 100 mm. , The cellulose concentration of the discharged solution was 11.5% by weight.

In addition, the temperature of the coagulation liquid was adjusted to 25 ℃, the concentration of 20% NMMO aqueous solution, the temperature and concentration of the coagulation liquid was continuously monitored using a refractometer. The filament exiting the coagulation bath passes through the washing process and enters the drying process.

In order to increase the degree of orientation of the amorphous region of the fiber to the maximum and to induce the densification of the crystal to produce a lyocell having a high modulus of elasticity with improved morphological stability, the angle α between the nozzle face and the outermost single yarn is 78 degrees. The length of the coagulation bath was 170 mm. The total length of the air layer and the coagulation bath is 240 mm.

[Example 2]

The length of the coagulation bath was 280 mm, and the total length of the air layer and the coagulation bath was 350 mm in order to set the angle α between the nozzle surface and the outermost single yarn in the industrial lyocell multifilament obtained in the same manner as in Example 1. It was.

Example 3

The physical properties of the yarn obtained by lyocell multifilament obtained in the same manner as in Example 1 with the nozzle outer diameter of 120 mm Φ and the angle α between the nozzle face and the outermost single yarn at 78 degrees are summarized in Table 1.

[Comparative Example]

The length of the coagulation bath was 70 mm, and the total length of the air layer and the coagulation bath was 140 mm in order to make the angle α between the nozzle face and the outermost single yarn in the industrial lyocell multifilament obtained in the same manner as in Example 1. It was. The physical properties of the obtained yarns are summarized in Table 1.

As shown in Examples 1, 2, and 3 of Table 1, the physical properties of the final filament were changed by changing the angle α between the nozzle surface and the outermost single yarn, the length of the coagulation bath, and the nozzle outer diameter. . In addition, when comparing Example 1 with the comparative example, it was confirmed that the physical properties of the final filament is changed according to the size of the angle formed by the nozzle surface and the outermost single yarn even if the nozzle outer diameter size is the same.

Therefore, in manufacturing the lyocell multifilament, it can be seen that the physical properties of the finally obtained yarn can be adjusted by adjusting the angle between the nozzle face and the outermost single yarn and the nozzle outer diameter.

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims. .

1 is a diagram showing an angle formed by the nozzle surface and the outermost single yarn.

Claims (2)

In the method for producing cellulose fibers, (A) preparing a liquid concentrated N-methylmorpholine N-oxide (NMMO) solution and cellulose powder into a swelled and homogenized cellulose solution; (B) extruding the cellulose solution such that the angle between the nozzle face and the outermost single yarn is 65 to 85 degrees through a spinning nozzle having an orifice number of 300 to 1,500; (C) a method of producing a cellulose multifilament improved mechanical properties and fibrillation resistance comprising the step of passing the extruded spun yarn through an air layer to reach a coagulation bath, followed by coagulation and washing with water. The method of claim 1, In step (B), the outer diameter of the spinning nozzle is set to 90 mm to 150 mm, and the length of the coagulation bath is adjusted to 80 mm to 400 mm.

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