KR20060078605A - Process for preparing multilobal fine denier polyester - Google Patents

Abstract

In the present invention, in the production of polyester release cross-section (three and four-sided cross-section) ultrafine fibers having a single yarn fineness of 0.5 to 1 denier and a single yarn number of 70 or more, the length of the delayed cooling portion is 20 mm or less, and the distance between the cooling air ejection surface and the filament is Spinning from 2mm to 30mm controls the distance between the delayed cooling section and the cooling air ejection surface of the lower part of the nozzle and thread, and also designes the cross section of the spinneret hole for high mold release degree, and the mold release degree is 3 or more. This favorable polyester microfiber release cross section yarn can be manufactured.

This is advantageous for the development of products with light weight and thermal insulation properties when the product is applied, as the circular cross-sectional diameter of the shaped cross section yarn is more than 2 times higher than that of the circular cross section with the same single yarn fineness. Indicates.

Shape diagram, shape section, micro fiber, delayed cooling part, cooling air, three leaf, four leaf

Description

Process for preparing multi-section polyester microfiber {Process for preparing multilobal fine denier polyester}             

1 is a schematic diagram of the three-leaf cross section of the spinneret used in the present invention.

2 is a cross-sectional schematic diagram of the four-leaf spinneret used in the present invention.

* Explanation of symbols in the drawings

A is the width of the middle part of the lobe in each trilobite or 4-lobed spinneret

B is the diameter of the terminal circular portion in each trilobite or tetralobal spinneret

C is lobe length at each trilobite or tetralobal spinneret

The present invention relates to a polyester release cross-section fine fiber and a method for producing the same, in particular single yarn fineness of 0.5 denier or more, 1.0 denier or less, in the melt spinning the polyester release cross-section fine fibers having a single yarn number of 70 or more, A method for producing a polyester release cross-section microfiber with excellent mold release, fairness and physical properties and good dyeability by adjusting the length of the delayed cooling section, controlling the distance between the ejection surface of the cooling air and the thread, and optimizing the spinneret for high mold release. It is about.

Recently, in the polyester fiber industry, development of differentiating materials having high value-added is actively progressed, and for this purpose, production of ultrafine fibers having a single yarn fineness of 1.0 denier or less is becoming common. Furthermore, attention has been focused on the development of polyester microfibers with single yarn fineness of 0.5 denier or less as well as hetero-splitting yarn microfibers.

However, in the case of a microfiber of a cross section, it is difficult to secure a cross section due to a sudden increase in the spinning draft, and there is a problem in that single yarn section or cross section unevenness occurs in the spinning process due to cooling unevenness between yarns.

In general, in the manufacture of polyester release cross-section microfibers, uniform cooling between filaments is an important factor in determining yarn quality, and proper spinning nozzle design is a key technology in securing mold release. In the general unidirectional cooling method, the front unidirectional cooling method does not achieve sufficient uniform cooling, resulting in deterioration of fairness due to fusion between yarns and nonuniform physical properties. As an alternative to compensate for these drawbacks, Korean Patent Publication No. 92-15834 proposes a cooling method by an omni-directional cylindrical delivery system cooling device, and the research for uniform cooling among filaments is steadily being conducted.

The present invention has a single yarn fineness of 0.5 denier to 1.0 denier and has a single yarn of 70 or more, and melt-spun a polyester release section (three and four leaf sections) of ultrafine fibers, the length of the delay cooling section and the distance between the cooling air ejection surface and the filament. The purpose of the present invention is to maintain a uniform cooling between the filaments, and to optimize the spinneret to produce a polyester release cross-section fine fiber having excellent mold release, fairness and physical properties and good dyeability.

In order to achieve the above object of the present invention,

The present invention is a polyester release cross-section fine fiber having a single yarn fineness of 0.5 to 1.0 denier and a single yarn number of 70 or more, after melt-spun polyethylene terephthalate polymer using spinnerets satisfying the following (1) to (4) Delay cooling by passing a delay cooling unit of 20 mm or less installed directly below the spinneret, and then passing uncooled yarn through a cooling unit controlled to have a maximum distance of 2 to 30 mm between the cold air extraction surface and the filament; It provides a polyester release cross-section fine fibers produced by the step of stretching the non-drawn yarn.

(1) B ≥ 2 × A

(2) C ≥ 2.5 × B

(3) spinneret cross-sectional area (mm2) ≤ number of wings (3 or 4) × 0.04

(4) three- or four-leaf cross-sectional shape

(Where A is the leaf width of the middle part in each trilobite or four-leaf spinneret, B is the diameter of the terminal circular part in each trilobite or four-leaf spinneret, C is the leaf length in each three- or four-leaf spinneret, see FIGS. 1 and 2). )

Moreover, it is preferable that the mold release degree of the said polyester mold release cross-section microfiber is 3.0 or more.

In addition, it is preferable that the physical properties of the polyester release cross-section microfiber satisfy the following 1) to 2.

1) Strength 4.0g / den or more

2) S = strength (g / den) x elongation at break (%) 1/2 ≥ 25

In addition, it is preferable that the unstretched yarn properties of the ultrafine fibers simultaneously satisfy the following 1) to 2).

1) T (χ) ≥ 1.2 g / den

T (χ); χ% strength (g) ÷ yarn denier

χ; Elongation at Break (%) ÷ 2

2) S = strength (g / den) x elongation at break (%) 1/2 ≥ 25

That is, the present invention is a method for producing a polyester release section microfiber which increases the degree of release by securing the cooling uniformity between yarns and optimizing the spinneret design by controlling the distance between the delayed cooling unit and the cold air blowout surface and the yarns at the bottom of the nozzle. It is about.

The core technology of the polyester microfiber manufacturing method is to design the cooling device to give the filament the same cooling effect at the same position, and to cool it immediately after being extruded from the spinneret to minimize the variation of the object to disturbance. Minimize quadrilaterals. To produce polyester microfibers with a high number of filaments and low single yarn fineness, cold air must be in uniform contact with all the filaments, and also control of vortices caused by cold winds or collisions between cold winds and yarns.

In the present invention, by shortening the length of the delayed cooling portion directly below the nozzle and controlling the distance between the cold air extraction surface and the filament, the uniform cooling between the filaments is enabled, thereby improving the processability and physical properties of the polyester microfibers. At this time, the length of the delayed cooling unit is 20mm or less, the distance between the cold air extraction surface and the filament was controlled to 2 ~ 30mm. When the length of the delayed cooling part directly under the nozzle exceeds 20 mm, the processability is lowered. When the distance between the cold wind extraction surface and the filament exceeds 30 mm, the physical properties are uneven and the processability is also lowered.

Polyester release cross-section spinnerets usually have a spinneret cross-sectional release (circle circle diameter / inscribed circle diameter) of 5 or less, whereas spinnerets used in the present invention increase the cross-sectional release rate of 8 or more and combine the above-mentioned near-cooling techniques to obtain You can raise the degree of release of the yarn to 3.0 or more. At this time, if the spinneret cross-sectional release degree is too low, the desired yarn release degree could not be produced, and if excessively high, the yarn fairness was inferior.

In addition, the core technical configuration of the present invention, the undrawn yarn is obtained by uniform cooling. In the case of unstretched yarn (POY) melt-spun according to the present invention, the following properties are compared with those of general unstretched yarn. That is, according to the present invention, by cooling the yarn directly under the spinneret and imparting a uniform cooling effect to the yarn, even when the single yarn fineness is low, the physical properties are uniform and the yarn strength is increased. In addition, even when the unstretched yarn was drawn at an appropriate draw ratio, it exhibited high strength properties as it is, and excellent mold release properties, physical properties and processability, and good dyeing cross-section microfiber yarns with good dyeability can be prepared.

The above uniform cooling effect has the following physical properties.

 T (χ) ≥ 1.2 g / den

          T (χ); χ% strength (g) ÷ yarn denier

          · Χ; Elongation at Break (%) ÷ 2

 S = strength (g / den) × elongation at break (%) 1/2 ≥ 25

Hereinafter, the present invention will be described in more detail with reference to the following examples.

<Property measurement method>

1) Evaluation of radiological fairness: ○-Very good, △-Normal, ×-Poor,

                                  ××-not available

2) T (χ); χ% strength at drawing (g) ÷ yarn denier

   χ; Elongation at Break (%) ÷ 2

3) Strength (g / den): strength of broken new city ÷ yarn denier

4) S: Strength (g / den) × Elongation at Break (%)

※ 2) ～ 4): Measure the strength and elongation properties of the yarn 30 times to find the average value

5) Deformation degree: circumscribed circle diameter ÷ inscribed circle diameter (measuring yarn cross section using SEM equipment)

6) Dyeing method: ○-Very good, △-Normal, ×-Poor

Sample: The yarn was knitted to a length of 20 cm with a circular knitting machine.

Salt bath: Disperse dye Ko-navy (S-type) was made with a dye concentration of 1% o.w.f., and then prepared with 1 g / L of a dispersant (VGT), pH 5.0 (acetic acid), and a liquid ratio of 1:15.

Dyeing test: The sample was placed in a salt bath, and the dyeing temperature was raised to 30 to 130 ° C. at a constant temperature of 1 ° C./min, followed by dyeing at 130 ° C. for 30 minutes. After the dyeing sample was sufficiently dried, a white plate was placed to visually determine dyeability.

Example 1

Using polyethylene terephthalate polymer with an intrinsic viscosity of 0.63, spinning temperature 297 ℃, spinneret dimensions of A, B, C are 0.07 / 0.16 / 0.40mm, spinneret length is 0.5mm, and the number of filaments is 72. The discharge amount was adjusted so that the fineness became 0.5 denier and melt spun at a spinning speed of 2,600 m / min. Cold air temperature was adjusted to 20 ℃, the cooling delay was installed directly under the spinneret, the length was adjusted to 5mm. In addition, the maximum distance between the cold air extraction surface and the filament was adjusted to 30mm. The stretched yarn was manufactured by drawing the undrawn yarn of the polyester microfiber at a draw ratio of 1.521. Table 1 shows the fairness, dyeability, and T (χ), S, and the like of the undrawn and drawn yarns.

Example 2

The single yarn fineness of the final stretched yarn was tested in the same conditions as in Example 1 except that 1.0 denier, the length of the delayed cooling portion was 20 mm, and the maximum distance between the cold air extraction surface and the filament was adjusted to 20 mm.

Comparative Example 1

The single yarn fineness of the final stretched yarn was 1.0 denier, the length of the delay cooling part was adjusted to 30 mm, and the maximum distance between the cold air extraction surface and the filament was adjusted to 20 mm, and the results are shown in Table 1 below.

Comparative Example 2

The single yarn fineness of the final stretched yarn was 1.0 denier, the length of the delayed cooling portion was 60 mm, and the maximum distance between the cold wind extraction surface and the filament was adjusted to 20 mm.

Comparative Example 3

The single yarn fineness of the final stretched yarn was 1.0 denier, the length of the delayed cooling portion was 20 mm, and the maximum distance between the cold air extraction surface and the filament was adjusted to 40 mm.

Comparative Example 4

The single yarn fineness of the final stretched yarn was 1.0 denier, the length of the delay cooling part was adjusted to 20 mm, and the maximum distance between the cold wind extraction surface and the filament was adjusted to 120 mm, and the results are shown in Table 1 below.

Comparative Example 5

The single yarn fineness of the final stretched yarn was 1.0 denier, the length of the delay cooling part was adjusted to 30 mm, and the maximum distance between the cold wind extraction surface and the filament was adjusted to 120 mm, and the results are shown in Table 1 below.

Comparative Example 6

The spinneret dimensions were carried out in the same manner as in Example 2 except that A, B, and C were each adjusted to 0.12 / 0.16 / 0.40 mm, and the results are shown in Table 1.

Comparative Example 7

The spinneret dimensions were carried out in the same manner as in Example 2 except that A, B, and C were each adjusted to 0.17 / 0.16 / 0.30 mm, and the results are shown in Table 1.

Comparative Example 8

The spinneret dimensions were carried out in the same manner as in Example 2 except that A, B, and C were each adjusted to 0.10 / 0.22 / 0.55 mm, and the results are shown in Table 1.

TABLE 1

According to the present invention, the single yarn fineness is 0.5 denier or more and 1.0 denier or less, and in the production of polyester release cross-section (three and four leaf cross-section) ultrafine fibers having a single yarn number of 70 or more, the delayed cooling portion and the cooling air ejection surface and the thread of the lower part of the nozzle By controlling the distance between them and optimizing the spinneret's design, it is possible to produce polyester-shaped cross-section microfibers with excellent mold release, fairness and physical properties at single yarn fineness of 1.0 denier or less.

This is advantageous for the development of products with light weight and heat retention characteristics when applied to the product as the circular cross-sectional diameter of the shaped cross section yarn is more than two times higher than the circular cross section having the same single yarn fineness, and the effect of gloss differentiation by the diffuse reflection gloss, A yarn having can be prepared.

Claims (4)

In polyester release cross-section fine fibers having a single yarn fineness of 0.5 to 1.0 denier and a single yarn number of 70 or more, The polyester polymer is melt spun using a spinneret satisfying the following (1) to (4), and then delayedly cooled by passing through a 20 mm or less delay coolant installed directly below the spinneret, and then a maximum between the cold air extraction surface and the filament. Passing uncooled yarn through a cooling section controlled at a distance of 2 to 30 mm; Polyester sectional cross-section ultrafine fiber, characterized in that produced by the step of stretching the undrawn yarn. (1) B ≥ 2 × A (2) C ≥ 2.5 × B (3) spinneret cross-sectional area (mm2) ≤ number of wings (3 or 4) × 0.04 (4) three- or four-leaf cross-sectional shape (Where A is the leaf width of the middle part in each trilobite or four-leaf spinneret, B is the diameter of the terminal circular part in each three- or four-leaf spinneret, and C is the leaf length in each three- or four-leaf spinneret) The method of claim 1, The polyester release cross-section fine fiber, characterized in that the degree of release of the polyester release cross-section fine fiber 3.0 or more. The method of claim 1, The polyester release cross-section microfiber, characterized in that the physical properties of the polyester cross-section microfiber satisfies 1) to 2 below. 1) Strength 4.0g / den or more 2) S = strength (g / den) x elongation at break (%) 1/2 ≥ 25 The method of claim 1, The polyester release cross-section microfine fiber, characterized in that the unstretched yarn properties of the microfine fiber at the same time satisfy the following 1) to 2). 1) T (χ) ≥ 1.2 g / den           T (χ); χ% strength (g) ÷ yarn denier           χ; Elongation at Break (%) ÷ 2 2) S = strength (g / den) x elongation at break (%) 1/2 ≥ 25

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