KR101272686B1 - Industrial high-strength Polyester fiber with Controlled by molecular weight and its manufacturing method - Google Patents

Abstract

The present invention is an industrial high-strength polyester fiber and a manufacturing method thereof, in producing a high-strength polyester fiber by melt-spun stretching a polyester chip having a number average molecular weight of 32,000 ~ 36,000, a weight average molecular weight of 60,000 ~ 64,000, It enhances the pack filtering to improve the purity of the polymer, and divides the hood heater into I, II, III stages, the length is 400 ~ 480mm, and the temperature is 340 ~ 400 ℃ to give a gradient to the manufacturing method. The fiber produced by the production method of the present invention is a polyester fiber having a strength of at least 10.6 g / d, an elongation at break of 12% or less, and a high temperature shrinkage of less than 11%. The polyester fiber prepared according to the present invention has high modulus, high strength, low elongation, almost no permanent strain, and thus can be usefully used as an industrial fiber for geogrid, webbing, and the like.

High strength, low elongation, permanent strain, industrial polyester fiber.

Description

Industrial high strength polyethylene terephthalate multifilament and its manufacturing method through molecular weight control {Industrial high-strength Polyester fiber with Controlled by molecular weight and its manufacturing method}

1 is a schematic view showing a manufacturing process of the present invention.

The present invention relates to an industrial high-strength polyester fiber and a method for manufacturing the same, and more particularly, industrial high-strength polyester fiber used for geogrids, webbing, etc. having high modulus and low elongation characteristics It relates to a manufacturing method.

In the conventional method for increasing the strength of polyester fiber, after melting a high viscosity chip, the molten polymer temperature is raised to 310 ° C, and sufficiently melted, and then filtered through a filter layer of 400 mesh or less, followed by a hood length of 280 mm and a subsequent temperature. Is set to 340 ° C. and the polymer is solidified with quenching air. Subsequently, the unstretched yarn obtained by winding at a low speed roller was stretched directly to a draw ratio 6.0 in one and two stages, and then relaxed and wound. At this time, the orientation degree at the time of unstretching was lowered by low speed winding, the high magnification of stretching was given, and the fiber of high strength was obtained. The physical properties of the polyester yarn manufactured by the above method and widely used in products such as industrial ropes have modulus of 60 g / d to 80 g / d, strength of 9.5 g / d or less, and cutting elongation of 13 to 18%.

In order to obtain higher strength by using a conventional spinning technique, when the stretching ratio is increased than the conventional stretching ratio, process problems and quality problems that cause many yarns are generated, resulting in poor post-processability. Therefore, it is difficult to obtain high-strength yarn with the existing technology due to the increase of manufacturing cost and the deterioration of product quality.

The present invention is to improve the purity of the polymer through the control of the molecular weight of the polyester chip and pack filtering, and to adjust the conditions of the hood length, hood temperature to increase the draw ratio higher than the conventional draw ratio of about 6.0 The technical problem is to make it possible to draw at 6.5 magnification which is a draw ratio, and to manufacture industrial high strength polyester fiber with a strength of 10.6 g / d or more, a cut elongation of 12% or less, and a high temperature shrinkage of less than 11%.

The present invention provides a method for producing an industrial high strength polyethylene terephthalate multifilament having a total fineness of 500 to 2000 denier, strength of 10.6 g / d or more, cutting elongation of 12% or less, and high temperature shrinkage of less than 11%, wherein the number average molecular weight is 32,000 to Polyethylene terephthalate multifilament produced by spinning from a polyethylene terephthalate chip having a weight average molecular weight of 60,000 to 64,000 is 36,000, the polyethylene tere characterized in that the number average molecular weight of 26,000 to 30,000, the weight average molecular weight of 48,000 to 54,000 It relates to a method for producing phthalate multifilament.

The number of the polyethylene terephthalate multifilament is characterized in that 192 or 384 pieces.

In the present invention, the length of the hood heater I stage 4 at the bottom of the spinneret nozzle is 120-160 mm, the length of the stage II 5 is 120-160 mm, and the length of the stage III 6 is 160 mm, respectively. Heater temperature is characterized by I stage 400 ~ 360 ℃, II stage 380 ~ 350 ℃, III stage 360 ~ 340 ℃.

In the present invention, a polyester chip having a number average molecular weight of 16,000 to 18,000 and a weight average molecular weight of 35,000 to 38,000 is solid-phase polymerized in a vacuum, and has a number average molecular weight of 32,000 to 36,000 and a weight average molecular weight of 60,000 to 64,000. And melt extruding the chip in the extruder 1 to spin through the nozzle of the spinneret, and gradient the hood heater temperature from 400 to 300 ° C. from above. By stretching at a high draw rate through excellent spinning workability and strength of more than 10.6g / d, less than 12% of the elongation, high temperature shrinkage of less than 11% polyester yarns and a method for producing the same.

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

A polyester chip having a number average molecular weight of 32,000 to 36,000 and a weight average molecular weight of 60,000 to 64,000 is melted in the extruder 1 and then filtered in a nonwoven filter (Mesh size of 30 μm) 3. According to the present invention, the length of the hood heater I stage 4 at the bottom of the spinneret nozzle is 120 to 160 mm, the length of the stage II 5 is 120 to 160 mm, and the length of the stage III 6 is 160 mm, and the hood heater I ( 4) the temperature of 400 ~ 380 ℃, the temperature of the hood heater II (5) to 380 ~ 360 ℃, the temperature of the hood heater III (6) to 360 ~ 340 ℃ quenching to solidify the radiated polymer Air intake (7) and exhaust (8). After applying the proper amount of oil in the oiling roller, the solidified yarn was preliminarily stretched in the high feed rollers GR 2 (10) and GR 3 (11), and then the 2 in the high feed rollers GR 3 (11) and GR 4 (12). A high ratio drawing is carried out and relaxed on the high rollers GR 4 (12) and GR 5 (13) before winding up.

Polyester yarns produced in such a process can be useful for geogrid, webbing, etc. because of good spinning performance and excellent yarn quality, high strength and modulus, and low cutting.

The method of performing the physical property evaluation in the Example and the comparative example was done as follows.

1) Measuring method of molecular weight of polyester chip

0.05 g of a polyester chip is dissolved in 80 ml of a mixed mixture of Chloroform and HFIP (1,1,1,3,3,3-Hexafluoro-2-propanol) in 1/2 at 80 ° C for 1 hour. The solution is diluted with 9 ml of chloroform and filtered.

       Instrument: Agilent 1100 GPC system

       Column: Waters styragel HR 5E + 4E

       Eluent: 98/2 mixture of chloroform and HFIP

       Flow Rate: 1.0 ml / min

       Detection: RI Detector

       Standard sample: PET

The number average molecular weight and the weight average molecular weight are measured under the above conditions.

2) Measuring modulus and elongation of yarn

After leaving the yarn in a standard condition, that is, a constant temperature and humidity chamber at a temperature of 25 ° C. and a relative humidity of 65% for 24 hours, the sample is measured by a tensile tester using the ASTM 2256 method.

3) How to measure high temperature shrinkage

The yarn is left for 24 hours in a standard condition, that is, a constant temperature and humidity room with a temperature of 25 ° C. and a relative humidity of 65%. It is left to stand in 150 degreeC oven for 30 minutes. The yarn is left for 24 hours in the standard condition. Measure the reduced elongation of the yarn. (L ₀ : Length measured under super load (0.01 g / d) after leaving the sample at standard condition for 24 hours, L ₁ : Length of sample reduced under super load (0.01 g / d) after applying heat for a certain time)

Examples 1 to 8 and Comparative Examples 1 to 6

A polyester chip with a number average molecular weight of 32,000 to 36,000 and a weight average molecular weight of 60,000 to 64,000 is extruded and quenched through a nozzle having a diameter of 0.6 mm, a length and diameter ratio (L / D) of 3, and a hole of 192 holes. (quenching) After cooling by air, focusing, oiling, and spinning high-density roller GR 4 at a speed of 2700m / min to 1500 denier was elongated under the spinning conditions of Table 1, the physical properties of the obtained yarn was measured.

[Table 1]

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Number average molecular weight (Mn) 33,500 33,500 33,500 33,500 34,900 34,900 34,900 34,900 Weight average molecular weight (Mw) 63,300 63,300 63,300 63,300 63,600 63,600 63,600 63,600 Type of filter Non-woven Non-woven Non-woven Non-woven Non-woven Non-woven Non-woven Non-woven Hood Heater Length I (mm) 120 120 120 120 160 160 160 160 Hood Heater Length II (mm) 120 120 120 120 160 160 160 160 Hood heater length III (mm) 160 160 160 160 160 160 160 160 Hood Heater Temperature I (℃) 400 380 360 360 360 380 360 360 Hood heater temperature Ⅱ (℃) 380 360 350 360 380 360 350 360 Hood heater temperature III (℃) 360 340 340 360 360 340 340 360 Denier 1515 1523 1512 1516 1515 1512 1521 1519 Modulus (g / d) 122 122 122 122 123 121 120 124 Strength (g / d) 10.6 10.7 10.8 10.8 10.6 10.7 10.6 10.6 Cutting Elongation (%) 11.9 10.5 10.2 10.6 11.5 12.0 11.3 12.0 High Temperature Shrinkage (%) 10.0 10.8 10.7 10.3 10.3 10.4 10.8 10.5

[Table 2]

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Number average molecular weight
(Mn) 30,500 30,500 30,500 39,200 39,200 39,200 Weight average molecular weight (Mw) 57,300 57,300 57,300 71,100 71,100 71,100 Type of filter wire 400 mesh wire 400 mesh wire 400 mesh wire 800 mesh wire 800 mesh wire 800 mesh Hood Heater Length I (mm) 120 120 120 120 120 120 Hood Heater Length II (mm) 160 160 160 160 160 160 Hood heater length III (mm) - - - - - - Hood Heater Temperature I (℃) 340 360 360 340 360 360 Hood heater temperature Ⅱ (℃) 340 360 340 340 360 340 Hood heater temperature III (℃) - - - - - - Denier 1510 1508 1521 1518 1520 1510 Modulus (g / d) 110 108 108 115 113 112 Strength (g / d) 10.2 10.1 9.9 10.2 10.3 10.3 Cutting Elongation (%) 12.5 12.8 13.0 12.5 12.8 12.2 High Temperature Shrinkage (%) 10.0 9.8 9.5 10.5 10.3 10.4

The present invention is to increase the purity of the polymer by the molecular weight of the polyester and filtering inside the pack, and to optimize the length and temperature of the hood heater to produce industrial high strength polyester fiber showing high modulus, high strength, low elongation Can be.

Claims (3)

In the manufacturing method of industrial high strength polyethylene terephthalate multifilament having a total fineness of 500 to 2000 denier, strength of 10.6g / d or more, cutting elongation of 12% or less, and high temperature shrinkage of less than 11%, Polyethylene terephthalate multifilament prepared by spinning from polyethylene terephthalate chip having a number average molecular weight of 32,000 to 36,000 and a weight average molecular weight of 60,000 to 64,000 has a number average molecular weight of 26,000 to 30,000 and a weight average molecular weight of 48,000 to 54,000. Method for producing a polyethylene terephthalate multifilament, characterized in that. The method for producing polyethylene terephthalate multifilament according to claim 1, wherein the number of polyethylene terephthalate multifilaments is 192 or 384. The length of the hood heater I stage 4 at the lower end of the spinneret nozzle is 120-160 mm, the length of the II stage 5 is 120-160 mm, and the length of the III stage 6 is 160 mm. Each hood heater temperature is I stage 400-360 degreeC, II stage 380-350 degreeC, III stage 360-340 degreeC, The manufacturing method of the polyethylene terephthalate multifilament characterized by the above-mentioned.

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