KR100786197B1 - A high elongation and low shrinkage polyester yarn, and a process of manufacturing for the same - Google Patents

Abstract

The present invention relates to a high-strength low-shrink polyester fiber and a method for manufacturing the same, wherein the regression line (X) and the thermal stress that decrease linearly at the maximum thermal stress point within the temperature range of 170 ° C. to 185 ° C. on the heat shrinkage stress curve are rapidly reduced to zero. There is an inflection point defined by the intersection of the regression line (Y) that decreases linearly to the point just before the decrease, and the single yarn fineness is 1 to 4 denier, the elongation is 70 to 90%, and the intensity is 3.5 to 4.2 g / d. And the boiling water shrinkage is 5% or less.

In the manufacturing method of the present invention, a heater (4) is installed between the focusing guide (3) and the first gourd roll (5) located below the spinneret (1) to heat the fibers and at the same time the second gourd roll (6). Also characterized by heating.

The high elongation low shrink polyester fiber of the present invention is thermally stable compared to the unstretched yarn, and thus is suitable as a yarn for producing a bi-shrink composite yarn.

In addition, the present invention is excellent in productivity and can simplify the yarn processing process.

High elongation, low shrinkage, polyester fiber, heat stability, bishrink composite yarn, heater.

Description

High elongation and low shrinkage polyester fiber and its manufacturing method {A high elongation and low shrinkage polyester yarn, and a process of manufacturing for the same}             

1 is a process schematic diagram of the present invention.

Figure 2 is a process schematic diagram of manufacturing a conventional polyester unstretched yarn (POY).

Figure 3 is a heat shrink stress curve of high elongation low shrink polyester fiber according to the present invention.

Explanation of symbols on the main parts of the drawings

1 spinneret 2 cooling device 3 focusing guide

DESCRIPTION OF SYMBOLS 4: Heater 5: 1st gourd roll 6: 2nd gourd roll

7: Winding machine A: Initial shrinkage start temperature

B: Maximum thermal stress temperature C: Maximum thermal stress D: Inflection point temperature

X: Regression line linearly decreasing at maximum thermal stress point

Y: Regression line linearly decreasing to the point just before the thermal stress shows a sharp decrease to zero.

The present invention relates to a high-strength low-shrink polyester fiber and a method for manufacturing the same, and more particularly, to a polyester fiber having a more stable thermal properties than unstretched yarn (POY) and simultaneously expressing high elongation and low shrinkage properties It is about a method.

Hereinafter, in the present invention, polyester fibers having high elongation but low shrinkage characteristics are abbreviated as "high elongation low shrink polyester fibers".

Polyester non-drawn yarn is largely classified into undrawn yarn (UDY) manufactured at a spinning speed of about 1,500 m / min and undrawn yarn (POY) having excellent physical properties and post-processing properties as it is manufactured at a spinning speed of 2,500 ~ 3,500 m / min. However, hereinafter, the polyester non-drawn yarn in the present invention means undrawn yarn (POY) produced a spinning speed of 2,500 ~ 3,500m / min.

Typical properties of polyester unstretched yarn (POY) are 80-160% of cut elongation and 30-70% of dry heat shrinkage, so physical and thermal properties are unstable, so they are rarely used alone during weaving and knitting. In case of using polyester unstretched yarn (POY) or by using a separate processing process to make physically and thermally stable yarn or using the characteristics of polyester unstretched yarn (POY) as in Japanese Patent Office No. 63-30421 It is mixed with stretched yarn or high shrinkage yarn and air mixed, and then it is used in the form of dihydrated mixed yarn by using resilience recovery difference.                         

In particular, since the development of new synthetic islands since the mid-80s, the use of bisulfate blended yarns has been widely developed worldwide, but due to unstable thermal properties of polyester unstretched yarns (POY), dyeing defects frequently occur in post processing. There was a problem. Therefore, in recent years, the development of polyester unstretched yarn (POY) having a low shrinkage property stable to the heat is urgently required.

As a conventional technique for producing polyester non-stretched yarn (POY) having low shrinkage characteristics, US Patent No. 2,604,667, etc., produces a polyester fiber having sufficient orientation and crystallinity without a separate stretching process by an ultra-fast spinning process of 4,750 m / min or more. We publish method.

However, the ultra-fast spinning method can express heat-stable low shrinkage characteristics well, but the cutting elongation is lowered to a level similar to that of the stretched yarn, so that the characteristics of the unstretched yarn disappear. When the biaxial blended yarn is applied, the soft texture and proper bulkiness disappear, which causes a drop in repulsion.

On the other hand, Korean Patent Application No. 96-79737 discloses a method for producing low shrinkage polyester fiber by heat treatment of polyester unstretched yarn (POY) in a separate process, Japanese Patent Application No. 96-15183 The present invention discloses a method in which a highly oriented unstretched polyester fiber is relaxed by heat treatment using a non-contact heating means to produce a low shrinkage yarn, and then twisted together with the stretched yarn or composited using a blending means. As described above, when polyester unstretched yarn (POY) is heat-treated in a separate process (rolling, sizing), a yarn having low shrinkage characteristics is manufactured and applied to a bi-shrink blended yarn, the softness is somewhat superior, but the dyeability of the original time is different. Due to the dyed line occurs and the bottom of the fabric piece is dirty, in particular, the problem often occurs that the rebound elasticity is insufficient, there was a problem that the application field is limited. In addition, when the heat treatment of the low-crystallinity high orientation unstretched polyester fibers in loose heat treatment, there was a problem that the repellency or shape retention significantly lacked.

On the other hand, US Patent No. 4,113,704 proposes a method for producing a low shrinkage yarn by modifying the polymer using a small amount of pentaerythritol or trimer acid alone, US Patent No. 5,034,174 Using a small amount of trimesic acid or trimellitic acid, etc., a method of preparing a low shrinkage yarn by modifying a polymer is disclosed. Korean Patent Publication No. 2002-0010789 discloses an acid modifier and a penta. Provided is a method of producing a low shrinkage yarn by modifying a polymer by adding a small amount of erythritol simultaneously.

However, the above methods have the advantage of increasing the elongation at the same spinning speed and increasing productivity and improving dyeability, but in reality, low shrinkage cannot be expressed. Although the properties of the unstretched yarn are satisfied, the shrinkage rate is 10%, which maintains the shrinkage rate of the existing stretched yarn, and thus its use is limited.

As described above, the conventional polyester unstretched yarn (POY) is thermally unstable due to its physical properties, so that the variation of physical properties is greatly increased by a heat treatment process to express the bishrinkage property in the production of the bishrink composite yarn. In the case of the twisted article, both sides of the outer and outer layers are different in color, the inclination of the string is increased due to the tension variation during the expansion of the rolled paper, and the shrinkage process has a problem of diaxial shrinkage effect.

On the other hand, in order to improve the thermal stability of the conventional polyester non-drawn yarn (POY), the process is complicated, such as twisting, braided yarn, twisted yarn, etc., there is a problem that the process is complicated and the manufacturing cost increases.

An object of the present invention is to provide a method for producing a high-strength low-shrink polyester fiber excellent in thermal stability only by spinning process without a separate heat treatment process.

The present invention has better thermal stability than ordinary polyester unstretched yarn (POY), which has low shrinkage characteristics, and has higher elongation than conventional polyester stretched yarn, resulting in bi-color difference or slanted lines when applied as a yarn for biaxial blended yarn production. It is an object of the present invention to provide a high-strength low-shrink polyester fiber having no volume and good volume and natural appearance.

In another aspect, the present invention provides a method for producing the high-strength low-shrink polyester fibers in only one step of spinning process without a separate heat treatment process.

The high-strength low shrinkage polyester fiber of the present invention for achieving such a problem has a single yarn fineness of 1 to 4 denier, an elongation of 70 to 90%, an intensity of 3.5 to 4.2 g / d, and a boiling water shrinkage rate. It is characterized by being 5% or less.

In addition, when the polyester fiber is produced by spinning, cooling and concentrating a polyester spinning solution through spinnerets and then passing the first gobrol roll and the second gobrol roll in turn, and then winding the polyester spinning solution. The heater 4 is installed between the focusing guide 3 and the first gobrol roll positioned below the spinneret 1 to heat the fibers and also to heat the second goth roll 6. It is done.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the high-strength low-shrink polyester fibers of the present invention, as shown in Figure 1 after spinning a conventional polyester spinning solution through the spinneret, and then cooled by the cooling device (2), the focusing guide installed under the spinneret The yarn spun by (3) is concentrated, and subsequently heated by a heater 4 located between the focusing guide 3 and the first gobrol roll 5, and then the first gob roll 5 and the first gob roll. It is manufactured by the process of winding the Gogo roll 6 in turn and then winding it up.

At this time, the present invention is characterized in that to heat the yarn focused in the focusing guide (3) with the heater (4) and at the same time to apply a temperature to the second goby roll (6).

Looking at the manufacturing method of the present invention in more detail with reference to Figure 1 as shown in Figure 1 is a process schematic diagram of the manufacturing method of the present invention.

The radial tension between the spinneret 1 and the first gourd roll 5 is preferably 0.25 to 0.45 g / d. More preferably, spinnerets having a spin draft of 250 to 350 are used. If the radial tension is less than 0.25 g / d, the crystal size cannot develop sufficiently, so it is difficult to express low shrinkage characteristics. If the radial tension exceeds 0.45 g / d, the yarn structure proceeds to highly oriented amorphous crystals. It is difficult to satisfy the characteristics of high elongation. The location of the focusing guide for the adjustment of the radial tension should be about 90 ~ 120cm away from the detention. If the position of the focusing guide is less than 90cm, it affects the cooling zone of the lower part of the prison and degrades the quality of the yarn such as the uniformity of the yarn. If it exceeds 120cm, the excessive tension is imparted to cause yarn defects such as wool and the above-mentioned radiation tension It exceeds the range and it is difficult to satisfy high elongation characteristics. In addition, it is preferable to adjust the temperature of the heater 4 located between the focusing guide 3 and the first gourd roll 5 to 80 to 125 ° C. It is preferable that the temperature of the 2nd goth roll 6 is 90-130 degreeC, and the winding speed is 4700-5200 m / min. When the heater 4 temperature is less than 80 ° C., the orientation increases due to the increase in stretching tension, so that the shrinkage rate increases, and when the heater 4 temperature exceeds 125 ° C., the draw ratio increases to reduce elongation, thus making it difficult to satisfy the conditions of high elongation low shrink yarns. When the temperature of the second goth roll 6 is less than 90 ° C., it is difficult to express low shrinkage characteristics. When the temperature of the second goth roll 6 exceeds 130 ° C., the vibration of the yarn is too severe in the process, resulting in poor processability. If the winding speed is less than 4700mpm, the crystal size of the yarn is not sufficiently developed, so it is difficult to produce low shrinkage performance, and at the winding speed exceeding 5200mpm, the reduction of elongation cannot be controlled due to the excessive development of crystal and orientation.

The yarn produced by the above production method has a single yarn fineness of 1 to 4 denier, elongation of 70 to 90%, and boiling water shrinkage of 5% or less.

In addition, the high-strength low-shrink polyester fiber of the present invention has a regression line (X) and thermal stress that decreases linearly at the maximum thermal stress point within the temperature range of 170 ° C to 185 ° C on the heat shrinkage stress curve as shown in FIG. There is an inflection point defined as the intersection of the regression line Y that decreases linearly to the point just before showing a sharp decrease to zero.

In other words, the stress at the inflection point is preferably 0.1 to 0.2 g / d.

Figure 3 shows the heat shrink stress curve of the high-strength low-shrink polyester fibers produced by the present invention.

Polyester undrawn yarn (POY) is difficult to measure the inflection point on the heat shrink stress curve, polyester drawn yarn does not appear on the heat shrink stress curve.

The high elongation low shrinkage polyester fiber of the present invention has an initial shrinkage start temperature (A) of 75 to 85 ° C, a maximum thermal stress temperature (B) of 95 to 110 ° C, and a maximum thermal stress (C) of 0.15 to 0.3 g. / d, and the difference between the maximum thermal stress temperature (B) and the initial shrinkage start temperature (A) is 20 to 30 ° C.

If the difference between the maximum thermal stress temperature (B) and the initial shrinkage start temperature (A) is less than 20 ° C., the yarn properties of conventional polyester unstretched yarn (POY) are close, and if it exceeds 30 ° C., The problem of getting closer to the physical properties occurs.

In the present invention, the properties of the yarns were measured by the following methods, respectively.

Elongation and strength

Measured by JIS L-1090 method. Using an Instron Model 4201 instrument, a 20 cm length sample is measured at an elongation of 20 cm / min under an initial load of 0.088 x dtex cN. Elongation is defined as the elongation at maximum (%), and strength is the maximum dividing load (g) by denier (unit: g / d).

Boiling water shrinkage

First, a skein is made with 10 turns of denier krill (the tension at the time of winding is displayed fineness x 1 / 10g). Measure the length (L ₀ ) by attaching the superload (display fineness × 1 / 25g) and the static load (display fineness × 2g) to the produced thread. After the heat treatment for 15 minutes in water at 100 ℃ and then pulled out to remove the water with a moisture-absorbent paper and left for 12 hours in the room, weighing the super load and static load and measure the length ( L ₁ ). The boiling water shrinkage is calculated by substituting the measured lengths as described below.

Boiling water shrinkage (%) = ( L ₀ - L ₁ ) / L ₀ × 100

Heat shrinkage characteristics

Using Kanebo Engineering's thermal stressor (model name, KE-2), an initial load of 0.88 cN / dtex was applied to the string-shaped sample, followed by heating at a rate of 2.5 ° C / sec. During the heating, the stress generated on the sample is recorded in the chart. 3 is an example of the heat shrink stress curve of the low shrink polyester fiber produced by the present invention. On the heat shrinkage stress curve of FIG. 3, the initial shrinkage start temperature (A) was defined as the time at which the sample that was thermally expanded with the increase in temperature was used. The maximum thermal stress temperature (B) was used when the thermal stress passed the highest point. The stress value at this time was taken as the maximum thermal stress (C). The inflection point was defined as the intersection of the regression line (X) which decreases linearly at the maximum thermal stress point and the regression line (Y) which decreases linearly until the final thermal stress decreases to zero.

Radiation draft

The spin draft is obtained by dividing the linear velocity (m / min) of the polymer by the first gourn roll velocity (m / min) when extruded from the mold.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

Example 1

The spinning solution of the polyethylene terephthalate polymer having an intrinsic viscosity of 0.65 is cooled through a spinneret (1) having a spinning draft of 260 and then cooled to a cooling device (2) as shown in FIG. Focusing the yarn spun with the focusing guide (3) installed below the centimeter, and then heated by a heater (4) of 100 ℃ installed between the focusing guide (3) and the first gourd roll (5), and then the first gourd roll (5) and the second gourd roll (6) having a temperature of 110 ° C. were sequentially passed, followed by winding at a winding speed of 4,900 m / min to prepare a polyester yarn of 90 denier / 48 filaments.                     

The result of measuring the physical property of the manufactured polyester yarn is shown in Table 1.

Example 2

The spinning solution of the polyethylene terephthalate polymer having an intrinsic viscosity of 0.65 is cooled through a spinneret (1) having a spin draft of 290, and then cooled to a cooling device (2), as shown in FIG. Focusing the yarn spun by the focusing guide (3) installed below the centimeter, and then heated with a heater (4) of 110 ℃ installed between the focusing guide (3) and the first gourd roll (5), and then the first gourd roll (5) and the second gourd roll (6) having a temperature of 90 ° C. were sequentially passed, followed by winding at a winding speed of 5,100 m / min to prepare a polyester yarn of 90 denier / 48 filaments.

The result of measuring the physical property of the manufactured polyester yarn is shown in Table 1.

Comparative Example 1

The spinning solution of the polyethylene terephthalate polymer having an intrinsic viscosity of 0.65 is cooled through a spinneret (1) having a spin draft of 360 as shown in FIG. 2 and then cooled to a cooling device (2), and 100 from the spinneret (1). After concentrating the yarn spun with the focusing guide (3) installed below the centimeter, and then continuously passed through the first gook roll (5) and the second gook roll (6) in turn and wound at a winding speed of 3,600m / min 90 A polyester yarn of denier / 48 filaments was prepared.

In the manufacturing process, the second gourd roll 6 was not heated, and the yarn focused in the focusing guide 3 was not heated by a heater.

The result of measuring the physical property of the manufactured polyester yarn is shown in Table 1.

Yarn property evaluation result division Elongation (%) Boiling Water Shrinkage (%) Strength (g / d) Initial shrinkage start temperature (A) (℃) Maximum Thermal Stress Temperature (B) (℃) Thermal stress (C) (g / d) Inflection point present Difference between Maximum Shrinkage Temperature and Initial Shrinkage Start Temperature (℃) Example 1 73.1 4.3 3.7 76.0 105.0 0.28 ○ 29.0 Example 2 78.2 4.0 4.0 81.5 102.0 0.19 ○ 20.5 Comparative Example 1 43.2 4.0 4.4 81.2 162.5 0.43 × 81.3

The high elongation low shrink polyester fiber of the present invention has better thermal stability than conventional polyester non-stretched yarn (POY), and thus has low shrinkage characteristics, and has high elongation than conventional polyester stretched yarn, so as a yarn for producing a bi-shrink blended yarn. When applied, it shows good volume and natural appearance without any discoloration difference or slanted lines.

In addition, the present invention can manufacture the high-strength low-shrinkage polyester fiber by only one step of the antiseptic process without a separate heat treatment process, simplifying the manufacturing process and low production cost.

Claims (10)

A high elongation low shrinkage polyester fiber, characterized in that the single yarn fineness is 1 to 4 denier, the elongation is 70 to 90%, the strength is 3.5 to 4.2 g / d, and the boiling water shrinkage is 5% or less. The regression line (X) according to claim 1, wherein the regression line (X) linearly decreases at the point of maximum thermal stress within the temperature range of 170 ° C to 185 ° C on the heat shrinkage stress curve, and the regression line decreases linearly to a point immediately before the thermal stress shows a sharp decrease to zero. A high elongation low shrink polyester fiber characterized by the presence of an inflection point defined by the intersection of (Y). The high elongation low shrinkage polyester fiber of Claim 2 whose stress of an inflection point is 0.1-0.2 g / d. The initial shrinkage start temperature (A) is 75 to 85 ° C, the maximum thermal stress temperature (B) is 95 to 110 ° C, and the maximum thermal stress (C) is 0.15 to 0.3 g /. d, wherein the difference between the maximum thermal stress temperature (B) and the initial shrinkage start temperature (A) is 20 to 30 ° C. In the process of spinning, cooling and focusing the polyester spinning solution through the spinneret, and then continuously passing the first gobrol roll and the second gobrol roll, and winding up, to manufacture the polyester fibers, the spinneret (1) below High elongation and low shrinkage, characterized in that the heater 4 is installed between the focusing guide 3 and the first goth roll 5 located in the heating chamber to heat the fibers and also the second goth roll 6. Method for producing polyester fiber. The method according to claim 5, wherein the temperature of the heater (4) provided between the focusing guide (3) and the first gourd roll (5) is adjusted to 80 to 125 ° C. The method for producing a highly elongated low shrinkage polyester fiber according to claim 5, characterized in that the temperature of the second goth roll (6) is adjusted to 90 to 130 ° C. The method for producing a highly elongated low shrinkage polyester fiber according to claim 5, wherein the distance between the spinneret (1) and the focusing guide (3) is set to 90 to 120 cm. The method according to claim 5, wherein the spinning drift is 250 to 350 and the winding speed is 4,700 to 5,200 m / min. The method according to claim 5, wherein the spinning tension between the spinneret (1) and the first goth roll (5) is adjusted to 0.25-0.45 g / d.

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