KR20090072062A - A technical polyester fiber with high tenacity and low shrinkage and its manufacturing process - Google Patents

Abstract

High strength-low shrinkage industrial polyester fiber and a manufacturing method thereof are provided to offer excellent workability by adjusting a spinning condition and a winding condition after selecting a proper polymer without an additive or polymer reforming. A manufacturing method of High strength-low shrinkage industrial polyester fiber includes a step for manufacturing solidified undrafted yarn by spinning a polyester polymer of which inherent viscosity is 0.95 -1.00, and a step for performing a drafting, heat-fixing, relaxation, winding, and stretching process of the undrafted yarn with a multistage stretching roller(1). The drafting, heat-fixing, relaxation, winding, and stretching process is processed with conditions of a stretching ration of 5.9 - 6.2, a relaxation rate of 10 - 13%, relaxation region temperature of 245 - 250°C, and winding speed of 3500m/min.

Description

High strength low shrink industrial polyester fiber and its manufacturing method {A technical polyester fiber with high tenacity and low shrinkage and its manufacturing process}

The present invention relates to an industrial polyester fiber having a higher level of strength while maintaining the same level of shrinkage as a conventional industrial polyester yarn, and a method for manufacturing the same, and more particularly, to an appropriate level to achieve the object of the present invention. After selecting the polymer of the high strength, low shrinkage industrial polyester fiber produced by optimizing the spinning conditions and winding conditions to produce a high-strength industrial polyester yarn while maintaining low shrinkage characteristics It is about.

In general, polyester fibers are widely used as industrial fibers because of their excellent physical properties such as excellent strength, initial modulus of elasticity, dimensional stability, etc., but the demand for yarns having higher strength continues to increase.

There are many ways to produce these high strength yarns, and at the polymer level, one can think of the direction of modifying the polymer itself or using additives and modifying or changing the spinning device or equipment, but from the commercial point of view, Investment costs are incurred, which reduces the relative economic gains that can be gained from achieving the technology.

Existing technologies are as follows.

U.S. Pat.No.4195052 discloses that the properties of yarns produced by stretching up to 97% of the maximum draw ratio are expressed in a strength of 8.54 g / d and a shrinkage rate of 5.0% (175 ° C). It is not applicable, and the claim of the present invention limits the scope of rights to 7.5g / d or more, so the level of physical properties that can be stably produced seems to be about 8.0g / d.

Japanese Patent Publication No. 64 -68515 small in intrinsic viscosity of 0.8 or more, and to use the polymer introduces techniques for producing the yarn of 3% or less, contraction ratio in strength of 9.5g / d, 150 ℃, carried out as one example strength 10.4g / d, Yarn with a shrinkage rate of 2.6% has been introduced, but this is a process of stretching unstretched yarn after swelling agent for a certain period of time after post-treatment.

Japanese Patent Publication No. Hei 3 -76810 introduces a yarn production technique of shrinkage rate at a strength of 9.2 g / d or more and 150 ° C. using a polymer having an intrinsic viscosity of 0.91 to 1.05, in order to achieve the target physical properties of the patent. It is not economical to add an end group blocker into the melt and to add a high temperature steam of 450 ° C. in the drying process.

Japanese Patent Application Laid-open No. Hei 2-61109 uses a polymer having an intrinsic viscosity of 0.70 to 1.05 to produce a yarn having a strength of 8.0 g / d or more and a shrinkage of 3.5% or less at 200 ° C. The heating plate is heated to 8.9g / d, shrinkage rate 3.3% yarn manufacturing conditions are shown in the examples, but in practice, there is a problem of energy and equipment renovation costs.

U.S. Patents 5238740 and 6015616 disclose techniques for producing high strength yarns by drawing unstretched yarns in separate drawing devices, but do not overcome the increase in shrinkage rate due to the increase in strength. Has a high shrinkage of 10.2%, a strength of 9.50 g / d, and a shrinkage of 6.8% at 177 ° C.

U.S. Patent No. 5277858 introduces a technique for producing yarns having a strength of 7.2 g / d or more and a shrinkage of 2.0% or less at 177 ° C., but the shrinkage is 3.3% at 8.56 g / d. In order to secure the residence time of the yarn in the area, the process speed is determined to be low, and the speed of the final roller stays at 2200 m / min.

In Korean Patent No. 0088316, a method for producing a polyester yarn having a strength of 8.0 g / d or more and a shrinkage of 1.5% or less (150 ° C. × 30 minutes) using a blending chip prepared by adding 6 to 35 wt% of a thermotropic liquid crystal polymer However, there is an economic disadvantage due to the addition of a process for manufacturing blending chips.

In Korean Patent No. 0070464, when stretching the undrawn yarn, a heat shrinkage of 4% or more of strength of 7.0 g / d or more using a contact heating plate having a stretching temperature of 180 to 210 ° C after stretching in the range of 0.9 to 1.3 times the natural drawing ratio. Although it introduces a yarn manufacturing method with less shrinkage characteristics, the strength is low and the shrinkage rate is high despite the addition of equipment.

Korean Patent No. 0133133 introduces a technique for producing an undrawn yarn, and then multi-stretching the undrawn yarn by the transverse drawing method to produce a yarn of more than 7.0 g / d, 175 ° C., and shrinkage of 2% or less at 30 minutes. As it is a step process, it is not economical in terms of manufacturing cost.

Korean Patent No. 1011325 introduces yarn production technology with strength of more than 8.0g / d and shrinkage of less than 1% (177 ℃, 0.22g / d load) in transverse stretching machine after the production of undrawn yarn using polymer having intrinsic viscosity of 0.9 or more. have. Similarly, after preparing the undrawn yarn, the following techniques were introduced for producing the yarn in the transverse drawing machine.

Korean Patent No. 0086089 introduces a method for producing polyester fibers by stretching and heat treatment in multiple stages by containing 1 ~ 10wt% of a side chaining agent in a polyethylene terephthalate polymer, and high speed spinning, and in Korean Patent No. 0084416 In manufacturing polyester yarns, a method of producing industrial polyester fibers with strengths of 8.0 g / d or more, dry heat shrinkage of less than 2%, and elongation of 15 to 25% by introducing process conditions has been introduced.

In Korean Patent No. 0084226, a multi-stranded polyester undrawn yarn having a birefringence of undrawn yarn of 0.02 or less and a maximum to minimum value of single yarn area of 1.5 or less is cross-stretched, heat treated, relaxed, and has a strength of 9.5 g / d or more, A method for producing high strength, low shrinkage polyester fibers with shrinkage at 175 ° C. of less than 2% is described.

In order to solve the problems and disadvantages of the prior art mentioned above, the present invention selects an appropriate polymer without changing equipment or modifying a polymer or using an additive, and then, by optimizing spinning conditions and winding conditions, excellent workability and existing industrial polyester An object of the present invention is to provide an industrial polyester fiber having a low shrinkage property of the fiber and expressing a higher level of strength and a method of producing the same.

The present invention, in the manufacture of high-speed, high-strength, low-shrink polyester fibers excellent in workability without equipment changes, polymer modification or additives, by selecting a polymer having an appropriate level of viscosity capable of expressing an appropriate level of strength Melt spinning the ester chips, and cooling solidified polyester unstretched filament yarn, as shown in FIG. 1, before conventional rollers are subjected to a conventional spinning emulsion (Kiss Roller or Jet Oiler) and then subjected to a multi-level roller Stretching, heat setting, and relaxation are carried out while the process is followed by a stretching process followed by a winding treatment.

The invention is a polyester solid-state polymerized chip having an intrinsic viscosity of 0.95 to 1.00 in order to produce high strength polyester fibers at a winding speed of 3500 m / min, which is higher than conventional industrial yarns, while maintaining a low shrinkage characteristic of less than 3% by a direct spinning process. After melt spinning with a cylinder temperature of 300 to 315 ℃ using a multi-stage high-pressure roller to wind the winder, and stretch-heat-fixed-relaxing-winding-stretching process. It maintains within draw ratios of 5.9 to 6.2, relaxation zone temperature of 245 ~ 250 ℃, and relaxation rate of 10 to 13% on multi-stage high-speed rollers. The present invention relates to a method capable of producing polyester fibers at a winding speed of 3500 m / min.

The present invention treats polyester undrawn yarn produced by melt spinning and cooling solidified with a polyester solid state polymerized chip having an intrinsic viscosity of 0.95 to 1.00 with a conventional spinning emulsion, and as a result of the embodiment of the present invention, polyester undrawn yarn Compared to conventional high strength, low shrinkage industrial polyester fiber manufactured through stretching process, heat setting, relaxation process and stretching process using multi-stage stretching roller, it shows higher strength of 9.0g / d or more while maintaining the same shrinkage rate. Ester fibers can be prepared.

In addition, a wide range of industrial papers, such as tarpaulins, truck covers or billboards produced using the polyester yarn according to the present invention exhibits high resistance and form stability to external load, thereby increasing the added value of the product using them.

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

In the present invention, the polyester melt, which melts the polymer having an intrinsic viscosity of 0.95 to 1.00 and is transferred to the spinneret, is in the state of the cooled polyester undrawn yarn before the first roller.

The polyester unstretched yarn is drawn in a multi-stage roller, and then undergoes a heat-setting process in the roller, then undergoes a relaxation process on a roller rotating at high speed, and undergoes a stretching process before final winding.

Here, in consideration of the characteristics of the solid-state polymerized polyester chip having an inherent viscosity of 0.95 to 1.00, melt spinning at an appropriate spinning temperature, while maintaining the low shrinkage characteristics of the existing industrial polyester yarn by varying the draw ratio and relaxation rate It produces excellent industrial polyester yarns that exhibit even higher levels of high strength properties.

In the present invention, the intrinsic viscosity of the polyethylene terephthalate chip is preferably 0.95 to 1.00, when the intrinsic viscosity is less than 0.95, the strength is difficult to develop and the heat resistance is lowered, and when the intrinsic viscosity exceeds 1.00, the radiation tension is increased on the radiation line. There is a problem in that it is difficult to control alignment.

In addition, the cylinder temperature of the extruder is preferably 300 to 315 ° C, and when the cylinder temperature is less than 300 ° C, the melt temperature is lower than the viscosity of the polymer, which may result in melt heterogeneity due to cosmetic melt generation, and also increases the spinning tension. According to the non-drawn yarn birefringence increases the problem that the drawability is deteriorated, when the cylinder temperature exceeds 315 ℃ thermal decomposition of the polyester melt is accelerated it becomes difficult to express the physical properties of the target level. The radiation beam, hood, gear pump temperature and cooling conditions can then be implemented in accordance with conventional conditions.

The unstretched yarn prepared under such conditions is passed through a multi-stage high-speed roller to undergo a stretching-heat setting-relaxing-winding-stretching process.

The draw ratio is preferably drawn to 5.9 to 6.2, and when the draw ratio is less than 5.9, it is difficult to express strength due to low fiber orientation, and when it exceeds 6.2, it is overdrawn, resulting in excessive shrinkage and poor yarn appearance. If this situation persists, complete remission occurs.

In addition, the relaxation rate is preferably 10 to 13%, the shrinkage rate is difficult to express when less than 10%, the thermal efficiency is deteriorated in the situation that the relaxation area residence time by the high-speed winding is relatively reduced when it exceeds 13% Vibration on the roller becomes severe and workability cannot be secured.

In addition, the relaxation area temperature is preferably 245 to 250 ℃, if the temperature is less than 245 ℃ heat amount to be transferred to the yarn is not enough, the relaxation efficiency is difficult to achieve the shrinkage rate, if it exceeds 250 ℃ yarn by thermal decomposition The decrease in strength and the generation of tar on the rollers increase the workability.

The above conditions were optimized to match the winding speed of 3,500m / min.

   By using the high strength, low shrinkage industrial polyester fibers as described above, it is possible to produce industrial paper such as tarpaulin, truck cover, or billboards by conventional methods.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope and scope of the present invention are not limited thereto. In the embodiment, the following evaluation methods and measuring methods are utilized.

(a) inherent viscosity of the polymer:

 A 0.4% polyester / solvent solution was prepared with a 6: 4 mixed solvent of phenol / 1,1,2,2-tetrachloroethane to give a flow rate of pure solvent through a standard capillary with Canon's Auto Visc II viscometer. After measuring the flow time of the ester / solvent solution, it was calculated by the Villemeier approximation formula (1) below.

      [Equation 1]

(b) Yarn strength and dedication:

A 250 mm sample was twisted at 80 times / meter based on ASTM D885 and then measured by tensile testing at a rate of 300 mm / min. The strength of the measured yarn divided by the weight of the yarn 9,000 m was determined as the strength of the yarn.

(c) Shrinkage:

The test light was determined as a percentage of the length difference after standing at 190 ° C. for 15 minutes while applying 0.01 g / d load to the sample.

  (d) Elongation ratio and relaxation rate are defined by the following equations (2) and (3).

       Example 1;

Using a polyester solid-state polymerized chip having an intrinsic viscosity of 0.90 to make the cylinder temperature of 295 ° C. of the extruder, the gear pump temperature, the radiation beam temperature, the hood temperature, and the cooling conditions were prepared in the usual manner, and then the unwinding polyester was produced. 1,000 denier-class yarns with fineness of final stretched yarn are manufactured at a draw ratio of 5.80, a relaxation rate of 11%, and a relaxation zone temperature of 3500m / min at 245 ℃.

    Examples 2-6 and Comparative Examples 1-10;

Using polyester chips with different viscosities, the cylinder temperature, elongation ratio and relaxation rate, and relaxation zone temperature of the extruder were differently performed as shown in Tables 1 and 2.

TABLE 1

 division  Example 1  Example 2  Example 3  Example 4  Example 5  Example 6  Chip viscosity  0.95  1.00  0.97  0.97  0.95  1.00  Cylinder temperature (℃)  300  315  315  315  300  315  Elongation ratio  5.9  6.1  5.9  6.2  5.9  6.0  % Relaxation  11  12  13  13  10  13  Relaxation zone temperature (℃)  245  250  245  250  250  250  Strength (g / d)  9.01  9.21  9.06  9.02  9.04  9.03  Body cut (%)  23.3  22.5  24.6  22.5  23.2  24.6  Shrinkage (%)  2.8  3.0  2.9  3.0  3.0  2.6  Yarn viscosity  0.77  0.81  0.79  0.75  0.76  0.80  Workability  Good  Good  Good  Good  Good  Good

TABLE 2

 division  Example 1  Example 2  Example 3  Example 4  Example 5  Example 6  Chip viscosity  0.88  0.98  0.93  0.90  0.95  0.90  Cylinder temperature (℃)  300  305  290  310  305  300  Elongation ratio  5.7  5.8  5.8  5.7  5.6  6.1  % Relaxation  11   12  11  12  11  12  Relaxation zone temperature (℃)  245  250  250  245  250  250  Strength (g / d)  8.25  8.79  8.82  8.68  8.81  8.71  Body cut (%)  22.5  23.9  22.9  23.5  24.1  22.8  Shrinkage (%)  2.8  2.7  3.0  2.9  2.9  3.1  Yarn viscosity  0.72  0.86  0.86  0.71  0.84  0.76  Workability  Good  Bad  Bad  Bad  Good  Bad

 division  Comparative Example 7  Comparative Example 8  Comparative Example 9  Comparative Example 10  Chip viscosity  0.93  0.95  0.93  0.93  Cylinder temperature (℃)  300  305  300  300  Elongation ratio  5.7  5.8  5.7  5.7  % Relaxation  9  14  13  13  Relaxation zone temperature (℃)  245  250  240  255  Strength (g / d)  8.81  8.65  8.77  8.54  Body cut (%)  23.8  24.8  24.1  24.6  Shrinkage (%)  3.2  2.5  3.2  2.6  Yarn viscosity  0.78  0.81  0.80  0.77  Workability  Good  Bad  Good  Bad

In Comparative Example 1, the polymer viscosity is low to express a certain level or more, and thus the physical properties targeted by the present invention were not obtained. This excessively caught unstretched birefringence level is high, the workability was poor because of the low elongation.

In Comparative Example 3, the physical properties of the yarns satisfy the target physical properties, but as in Comparative Example 2, the spinning temperature was set lower than the polymer viscosity, and thus the workability was poor due to the deterioration of the elongation due to the increase in the radial tension. In the remaining melting process with excessively set the spinning temperature relative to the polymer viscosity, it was confirmed that not only the radioactivity was poor due to thermal decomposition of the polymer, but also the strength and viscosity of the yarn were low.

Comparative Example 5 had a low level of strength of the final drawn yarn produced by not applying an appropriate draw ratio for expressing yarn properties, whereas Comparative Example 6 was produced by not only applying a draw ratio excessively but also having a poor appearance. The level of trimming was high during the process.

 Comparative Example 7 has a low level of relaxation applied, so the strength of the final yarn is high, but no shrinkage was observed. Not only did the appearance of poor, but also the workability was not good.

In Comparative Example 9, the amount of heat supplied to the yarn was set low by setting the temperature of the relaxation region lower than the applied relaxation rate, and the shrinkage ratio remained at a high level. In Comparative Example 10, although the physical properties of the final yarn met the target level of the present invention, the relaxation region The excessive temperature was set and the tar on the roller was severe during long term operation, resulting in poor appearance and workability of the final yarn.

1 is a schematic view of a manufacturing process of a high strength, low shrinkage industrial polyester fiber according to the present invention.

Claims (4)

A polyester fiber produced by melt- spinning a polyester chip having an intrinsic viscosity of 0.95 to 1.00 by stretching, heat fixing, relaxation, stretching and winding in a multistage stretching roller. (1) more than 9.0g / d strength (2) 3% or less shrinkage     (3) High strength, low shrinkage industrial polyester fiber, characterized in that the yarn viscosity is 0.77-0.90. 1) melt spinning the polyester polymer having an intrinsic viscosity of 0.95 to 1.00 to produce a cooled solidified non-drawn yarn; 2) A method for producing a high strength, low shrinkage polyester fiber, characterized in that the non-drawn yarn is manufactured through a draw-heat fixation-relaxation-winding-stretching process using a multi-stage stretch roller.       (a) Draw ratio: 5.9 to 6.2       (b) relaxation rate: 10-13%       (c) Relaxation zone temperature: 245 to 250 ℃       (d) Winding speed: 3500m / min The method for producing a high strength, low shrinkage industrial polyester fiber according to claim 2, wherein the cylinder temperature is 300 to 315 ° C in step 1). Industrial forge, such as tarpaulin or truck cover paper containing a high-strength, low-shrinkage industrial polyester fiber produced according to claim 1.

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