KR100719045B1 - A high strength low shrinkage polyester drawn yarn, and a process of preparing for the same - Google Patents

Abstract

The present invention relates to a high-strength low-shrinkable polyester stretched yarn used in industrial yarns and a method of manufacturing the same. The manufacturing method of the present invention is lowered from the bottom bottom surface of the heat insulating plate 3 located in the cooling delay region (I) at the time of manufacturing the polyester yarn by the direct radiation drawing (DSD) process provided with the cooling delay region (I). Oiling device 8 is installed at 500 ~ 1,500mm position to attach spinning oil to spinning yarn to make the freezing point of molten polymer discharged from spinning cap uniform, and between rollers of relaxation zone (III). It is characterized by adjusting the relaxation stress of the yarn by installing one or two tension guides (9). As a result, the high-strength, low-shrinkable polyester stretched yarn produced by the present invention has improved various physical properties and improved operability.

Industrial Yarn, Polyester Stretched Yarn, High Tenacity Low Shrinkage, Solidification Point, Direct Spinning, Cooling Delay Zone, Oiling Equipment, Stretchability

Description

A high strength low shrinkage polyester drawn yarn, and a process of preparing for the same}

1 is a process schematic of the prior art for producing a high strength low shrinkage polyester stretched yarn

Figure 2 is a process schematic diagram of the present invention for producing a high strength low shrinkage polyester stretched yarn.

※ Explanation of Codes on Major Parts of Drawings

1: spinneret 2: Hood Heater 3: Insulation plate

4: Quenching chamber 4a: Quenching screen

5, 8: Oil ring device 6a ~ 6f: 1st high roller ~ 6th high roller

7: Winder 9: Tension guide I: Cooling delay area

Ⅱ: Stretching region Ⅲ: Relaxing region

The present invention relates to a high-strength low-shrink polyester stretched yarn used in the manufacture of seat belts or webbing, and a method of manufacturing the same.                         

Specifically, the present invention, when the high-strength low-shrinkage polyester non-stretched yarn is manufactured by direct spinning (hereinafter referred to as "DSD") method, it is unstained by uniformizing the solidification point of the molten polymer discharged from the spinneret It relates to a method of uniformly controlling the physical properties between each filament of the gentleman.

More specifically, when the high-strength low-shrinkable polyester stretched yarn is manufactured by the DSD method, even when the spinning speed is increased to improve productivity, the solidification point of the melted polymers can be minimized to improve the uniformity of the unstretched yarn. It also relates to ways to improve operability.

Polyester drawn yarns, which are generally used as industrial yarns, are manufactured by spinning and stretching processes in which a cooling delay zone (I) is installed.

As a specific prior art, as shown in FIG. 1, the cooling delay area I in which the hood heater 2 and the heat insulating plate 3 are arranged up and down is provided between the spinneret 1 and the cooling chamber 4 so that the orientation of the undrawn yarn can be adjusted. The method of suppressing and improving elongation has been used.

In the prior art, the molten polymer discharged from the spinneret (1) is passed through a high temperature hood heater (2) and a monomer adsorption heat insulating plate (3) in sequence, and then solidified in the cooling chamber (4), which is mainly an open type (open type). After the non-drawn yarn was prepared, the oil was lubricated to the non-drawn yarn and stretched at a high magnification to prepare the drawn yarn.

However, such a conventional method has a problem that the degree of orientation of the undrawn yarn increases, the freezing point decreases, the cooling becomes uneven when the spinning speed increases, and the uniformity between the undrawn yarn filaments is lowered. As the uniformity between the undrawn yarn filaments is lowered, the drawability in the drawing process is poor, and eventually, the bleeding occurs in the drawn yarn, thereby degrading the quality.

Therefore, the conventional method has a limit that can not increase the spinning speed above a certain level, thereby limiting the improvement in productivity.

An object of the present invention is to prepare a method of manufacturing a high-strength low-shrinkable polyester stretched yarn that can improve the stretchability and productivity by uniformly managing the freezing point of the melted polymer even when the spinning speed is increased to solve such conventional problems It is to.

Another object of the present invention is to provide a high-strength low-shrinkable polyester stretched yarn which is excellent in physical properties and quality and useful as an industrial yarn.

The present invention is directed to the yarn tension during the solidification point and loosening treatment of the melted polymer so that the stretchability and yarn properties do not decrease even when increasing the spinning speed to improve the productivity when manufacturing a high strength low shrinkage polyester drawn yarn by a direct spinning process It is intended to provide a method that can be managed uniformly. In another aspect, the present invention is to provide a high-strength low-shrinkable polyester stretched yarn useful in industrial yarns such as seat belts with good yarn properties and quality.

In the manufacturing method of the high-strength low-shrinkage polyester stretched yarn of the present invention for achieving these problems, the hood heater (2) and the heat insulating plate (3) is arranged up and down between the spinneret (1) and the cooling chamber (4) In manufacturing a high strength low shrinkage polyester by a direct spin draw process in which a cooling delay region (I) is provided, the oil is positioned 500 to 1,500 mm downward from the bottom surface of the heat insulating plate 3. Attaching the spinning oil to the spinning yarn by installing the ring device (8), it is characterized by adjusting the relaxation stress of the yarn by installing one or two tension guides (9) between the high roller of the relaxation zone (III) do.

In addition, the high-strength low-shrinkage polyester stretched yarn of the present invention has a thermal stress value of 0.015 to 0.065 g / d measured at an initial load of 0.11 g / d at 170 ° C., and a thermal stress measured at an initial load of 0.01 g / d at 170 ° C. The numerical value is 0.003 to 0.020 g / d, and the average shrinkage stress measured at 170 ° C. is 0.02 to 0.10 g / d.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention discharges a polyester solid polymer chip (Chip) having an intrinsic viscosity of 0.78 ~ 0.90 at a spinning temperature of 273 ~ 288 ℃ through the spinneret (1), and then discharged the melt polymer (Melt polymer) hood heater ( The cooling of the molten polymer is delayed while passing through the cooling delay region I in which 2) and the heat insulating plate 3 are arranged up and down.

At this time, the temperature of the hood heater 2 is preferably 270 ~ 330 ℃, length is preferably 200 ~ 400mm. If the temperature of the hood heater 2 is less than 270 ° C. and the length is less than 200 mm, the drawability may be difficult, so that weaving may be difficult. In addition, when the temperature of the hood heater 2 exceeds 330 ° C and the length exceeds 400mm, the molten polymer may be decomposed to lower the yarn strength.

On the other hand, it is preferable that the length of the said heat insulation board 3 is 60-300 mm. When the length of the insulation plate 3 is less than 60mm, the cooling delay effect may not be expressed. When the length exceeds 300mm, the solidification point of the molten polymer is excessively lowered, and thus, the radial tension is drastically reduced, which may make winding difficult.

In addition, the yarn residence time in the cooling delay region (I) is preferably adjusted to 0.02 to 0.08 seconds. When the residence time is less than 0.02 seconds, the cooling delay effect of the molten polymer may be reduced, and the birefringence rate of the undrawn yarn may be increased, thereby lowering the stretchability. On the other hand, when the residence time is more than 0.08 seconds, the tension of the undrawn yarn discharged from the spinneret 1 is lowered, so that the woofer and cutting may be severe due to the vortex phenomenon, it may be difficult to operate.

Subsequently, the molten polymer having passed through the cooling delay region (I) as described above is solidified in the cooling chamber 4 and the spinning oil is applied to the molten polymer by the oiling device 5, or the cooling chamber 4 is provided. Immediately after solidification in the inside, the spinning oil is imparted to the undrawn yarn solidified by the oiling device 8.

As described above, the manufacturing method of the present invention is characterized in that the spinning oil is imparted to the oiling device 8 during or immediately after the solidification of the melted polymer or the unstretched monofilaments to uniformize the solidification point and physical properties thereof. .

The oil ring device (8) is installed in the lower position of 500 ~ 1500mm from the bottom bottom surface of the heat insulating plate (3). When the distance from the heat insulating plate 3 is less than 500 mm, the spinning oil is denatured or the molten polymer is rapidly cooled and the inner and outer layers of the unstretched yarn become uneven, so that winding is difficult. On the other hand, when the distance from the heat insulating plate 3 exceeds 1,500 mm, the problem that the cooling delay effect is insignificant occurs.

At this time, the spinning speed is more preferably adjusted to 500 ~ 800m / min, the radiation tension is 0.10 ~ 0.25g / d or less. If the spinning speed is less than 500m / min, the yarn quality may be reduced due to the occurrence of turbulence, and if it exceeds 800m / min, it may be deteriorated and the operability may be reduced.

Subsequently, as described above, the unstretched yarn which has been subjected to the solidification and adhered to the spinning oil is stretched and heat treated between the first high roller 6a and the fourth high roller 6d, which are the stretching regions II.

Oil ring device 5 may be installed on top of the first high roller 6a for apostle maintenance and secondary oil ring.

It is preferable to adjust the draw ratio in the said stretching area | region (II) to 5-6 times, and to heat-treat the temperature to 210-250 degreeC.

If the draw ratio is less than 5 times, the yarn strength may be reduced, and if it exceeds 6 times, the quality of the yarn may be reduced due to the occurrence of wool.

If the heat treatment temperature is less than 210 ℃, the shrinkage of the yarn is improved to reduce the morphological stability and heat resistance of the yarn, if the temperature exceeds 250 ℃, the generation of tar on the cutting and high rollers may increase the operationability have.

Subsequently, the stretched yarn having passed through the stretching region (II) was subjected to a relaxation temperature of 150 to 220 ° C. and 5 to 12% in the relaxation region (III) between the fourth high roller (6d) and the sixth high roller (6f). A high strength low shrinkage polyester drawn yarn is prepared by relaxing at a relaxation rate of.                     

If the relaxation temperature is higher than 220 ℃ it is difficult to lower the relaxation stress, if less than 150 ℃ may be difficult to wind the yarn flow on the high roller on the high roller. In addition, if the relaxation rate is less than 5%, the required low-shrinkage property is less likely to be expressed, and if it exceeds 12%, the yarn flow on the high roller is severe.

The production method of the present invention can keep the orientation of the undrawn yarn low even at high speed spinning, and high magnification stretching is possible at the time of stretching. In addition, the production method of the present invention can uniformly manage the physical properties of the undrawn yarn, it is possible to uniformly manage the physical properties of the drawn yarn and improve the quality.

The polyester stretched yarn of the present invention prepared as described above has a thermal stress value of 0.015 to 0.065 g / d at a measurement condition of 170 ° C × initial load of 0.11 g / d, and a heat measured at 0.01 ° C / d of an initial load at 170 ° C. The stress value is 0.003-0.020 g / d, and the average shrinkage stress measured at 170 degreeC is 0.02-0.10 g / d.

In addition, the polyester stretched yarn of the present invention has a birefringence (Δn) of 0.1800 to 0.1950, a degree of crystallinity (Xc) of 49.5 to 55.0%, a degree of amorphous orientation (fa) of 0.44 to 0.55, and a degree of crystal orientation (fc) of 0.905 to 0.925.

In addition, the polyester stretched yarn of the present invention has a shrinkage of 0.10 to 1.60% when the initial load is applied 0.01g / d under the measurement conditions of 170 ℃ × 2 minutes, the initial 0.10 g / d under the measurement conditions of 170 ℃ × 2 minutes When applied to load, it has a shrinkage of -1.0% to -1.5%. As a result, the polyester drawn yarn of the present invention has high strength and low low shrinkage.

In the present invention, the physical properties of the yarn and the like were measured by the following method.                     

Shrinkage (%)

Yarn shrinkage under constant tension is measured by a Testrite Co., Ltd. Testrite MK-V instrument under test conditions of 170 ° C. × 2 minutes.

Radiation stress (g)

Measure at the top of the first high roller 6a using a tension meter.

Thermal stress (g / d)

Measure using Kanebo Engineering Thermal Stress Meter (Model: KE-2). The temperature increase rate is set to 2.5 ℃ / second. The sample is prepared by applying the KE-2 sampler and the method of weaving the sample (KE-2 instruction manual) in the form of a loop of 10 cm. For ultra loads, 20 g (0.01 g / d) and 220 g (0.11 g / d) apply.

Thermal stress measurements are taken as the average of three measurements.

Average shrinkage stress

FTA-500 is used to measure the maximum and minimum shrinkage stress values and then average them. At this time, the stretching ratio is set to 100%, the chamber temperature is set to 150 ℃ or 170 ℃, the chamber residence time is set to 9.6 seconds.

Birefringence (Δn)

It was measured by an interference microscope (from Carl Zeiss, Germany, model name: JENAPOL -U INTERPHAKO). The birefringence is calculated by the formula below.

Where R is the compensator retardation, S is the retardation of quartz shim, and D is the fiber diameter. In addition, the units of R and S are nm and the units of D are μm.

Strength / Shinto

The average value is obtained by measuring ten times with a tensile tester of Instron Co., Ltd. (sample length: 250mm, tensile speed: 300mm / min).

Density (ρ)

The stretched yarn is added to a density meter (manufactured by Shibayama, Japan, Model SS) composed of a mixed solvent of normal heptane and carbon tetrachloride, and left at 25 ° C. for 1 day, and then the density is measured.

Crystallinity [Xc (%)]

Based on the density (ρ) value above, the theoretical density of the complete crystal region of polyester (ρ _c = 1.457 g / cm 3) and the density value of the complete amorphous region (ρ _a = 1.336 g / cm 3) Find the formula

Crystal orientation (Fc)

Full width at half-maximum intensity (FWHM) showing the characteristics of crystal orientation by performing azimuthal scanning on the (010) and (100) planes of the crystal with an X-ray diffractometer. ), The crystal orientation (Fc) of the drawn yarn was calculated. The equation for calculating the crystal orientation (Fc) from the full width (FWHM) is as follows.

Non-orientation orientation (Fa)

The non-orientation degree Fa of the drawn yarn is obtained by substituting the crystallinity degree Xc, the crystal orientation degree Fc, and the birefringence index DELTA n in the following equation.

Δn _c is the intrinsic birefringence of the crystal (0.29), and Δn _a is the intrinsic birefringence of the amorphous (0.20).

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

After discharging the polyester solid-state polymerization chip (Chip) having an intrinsic viscosity of 0.79 at a spinning temperature of 273 ° C. through the spinneret (1), the ejected molten polymer was 300 mm in length and 300 ° C. in a hood heater (2) And delayed cooling while passing into the cooling delay area (I) consisting of a heat insulating plate having a length of 60 mm. At this time, the residence time of the molten polymer in the cooling delay region was 0.04 seconds, the spinning speed was 600m / min. Subsequently, the molten polymer is solidified in the cooling chamber 4 having a length of 1,000 mm, and at the same time, the spinning oil is supplied to the oil ring device 8 installed 600 mm downward from the heat insulating plate to produce undrawn yarn. Then, while passing through the first high rollers 6a to the fourth high rollers 6d, the film is stretched at 5.65 times and heat-treated at 240 DEG C., while the fourth high rollers 6d and the sixth high rollers 6f are passed through. Relax treatment was performed at a relaxation rate of 11% and a relaxation temperature of 170 ° C., followed by winding to prepare a polyester drawn yarn of 1,000 denier. The results of evaluation of various physical properties of the prepared polyester drawn yarn are shown in Table 2.

Example 2-Example 7

A polyester drawn yarn is manufactured under the same process and conditions as in Example 1 except for changing the manufacturing conditions as shown in Table 1. The results of evaluating the physical properties of the prepared polyester drawn yarn are shown in Table 2.

<Table 1> Manufacturing Conditions

division Example One 2 3 4 5 6 7 Chip Intrinsic Viscosity 0.79 0.83 0.85 0.85 0.85 0.85 0.90 Spinning temperature (℃) 273 278 280 280 280 280 284 Hood heater Temperature (℃) 300 300 300 330 270 300 300 Length (mm) 300 300 300 200 400 300 300 Insulation board length (mm) 60 300 100 100 100 200 200 Polymer retention time (min) in cooling delay area (Ⅰ) 0.04 0.06 0.04 0.03 0.06 0.05 0.05 Spinning speed (m / min) 600 600 600 700 500 600 600 Insulation plate and oiling device distance (mm) 600 600 600 800 550 550 Stretch ratio (times) 5.65 5.50 5.50 5.50 5.50 5.35 5.35 Heat treatment temperature (℃) 240 240 240 240 240 220 220 % Relaxation 11.0 6.0 10.0 9.0 8.5 10.0 10.0 Relaxation temperature (℃) 170 190 160 220 200 210 210

<Table 2> Property Evaluation Results

division Example One 2 3 4 5 6 7 Shrinkage when initial load of 0.01g / d is applied under measurement condition of 170 ℃ × 2 minutes (%) 1.0 0.9 1.3 1.4 1.1 1.0 1.3 % Shrinkage when initial load of 0.10 g / d is applied under measurement condition of 170 ℃ × 2 minutes -0.9 -1.2 -0.5 -0.3 -1.0 -0.8 -0.4 Average shrinkage stress at 170 ℃ (g / d) 0.10 0.03 0.05 0.05 0.06 0.08 0.07 Thermal stress value measured at 0.11 g / d initial load at 170 ° C 0.051 0.018 0.034 0.040 0.041 0.048 0.046 Birefringence (△ n) 0.1943 0.1860 0.1890 0.1920 0.1870 0.1820 0.1850 Crystallinity (Xc) 50.3 49.6 52.3 53.4 50.1 51.2 51.9 Non-orientation (fa) 0.50 0.44 0.50 0.54 0.47 0.48 0.49 Crystal orientation (fc) 0.924 0.915 0.910 0.908 0.918 0.913 0.910 Thermal stress value measured at 0.01 g / d initial load at 170 ° C 0.018 0.004 0.008 0.010 0.011 0.013 0.010

The present invention can uniformly manage the solidification point of the molten polymer even at a high spinning speed, thereby improving productivity and improving the physical properties and quality of the yarn. Therefore, the high strength low shrinkage polyester drawn yarn of the present invention is very useful as an industrial yarn used in the manufacture of seat belts, webbing, and the like.

Claims (13)

High strength due to the direct spin draw process, in which the cooling delay area (I) is arranged between the spinneret (1) and the cooling chamber (4) with the hood heater (2) and the heat insulating plate (3) arranged up and down. In manufacturing low-shrinkable polyester, the oiling device 8 is installed at a position 500 to 1500 mm downward from the bottom surface of the heat insulating plate 3 to attach spinning oil to the spinning yarn, and the relaxation region (III). Method of manufacturing a high-strength low-shrinkable polyester stretched yarn, characterized in that to control the relaxation stress of the yarn by installing one or two tension guides (9) between the rollers. The method according to claim 1, wherein the oiling device (8) is installed at a position 500 to 1,000 mm below the bottom surface of the heat insulating plate. The method according to claim 1, wherein the temperature of the hood heater (2) is 270 to 330 ° C and the length is 200 to 400 mm. The method for producing a high strength low shrinkage polyester stretched yarn according to claim 1, wherein the length of the heat insulating plate (3) is 60 to 300 mm. The method for producing a high strength low shrinkage polyester stretch yarn according to claim 1, wherein the yarn residence time in the cooling delay region (I) is 0.02 to 0.08 seconds. delete In the drawn yarn produced by the manufacturing method of claim 1, the thermal stress value measured by the initial load 0.11 g / d at 170 ℃ is 0.015 ~ 0.065 g / d, the heat measured by the initial load 0.01 g / d at 170 ℃ A high strength low shrinkage polyester stretched yarn having a stress value of 0.003 to 0.020 g / d and a mean shrinkage stress measured at 170 ° C. of 0.02 to 0.10 g / d. The high tensile low shrinkage polyester stretched yarn according to claim 7, wherein the birefringence (Δn) of the polyester stretched yarn is 0.1800 to 0.1950. The high-strength low-shrinkage polyester stretched yarn according to claim 7, wherein the degree of crystallization (Xc) of the polyester stretched yarn is 49.5 to 55.0%. The high-strength low-shrinkage polyester stretched yarn according to claim 7, wherein the non-orientation degree (fa) of the polyester stretched yarn is 0.44 to 0.55. The high tensile low shrinkage polyester stretched yarn according to claim 7, wherein the crystal orientation degree (fc) of the polyester stretched yarn is 0.905 to 0.925. In the drawn yarn manufactured by the manufacturing method of claim 1, a high strength low shrinkage polyester stretched yarn having a shrinkage ratio of 0.10 to 1.60% upon application of an initial load of 0.01 g / d under measurement conditions of 170 ° C. × 2 minutes . In the drawn yarn prepared by the method of claim 1, the high strength and low shrinkage polyester, characterized in that the shrinkage rate is -0.1 to -1.5% upon application of an initial load of 0.10 g / d under the measurement conditions of 170 ℃ × 2 minutes Drawing company.

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