KR20030073012A - A process for preparing polyester multifilament yarns having high strength and excellent flatness and gathering properties - Google Patents

Abstract

PURPOSE: A manufacturing method of high strength polyester multi filament yarn which is characterized by maintaining collectivity between filaments and having excellent flatness is provided. CONSTITUTION: High strength polyester multi filament yarn is obtained by the steps of: melt-spinning polyester polymer; passing the polymer through a godet roller(10); passing the filament yarn through a closed-type interlacer(20); advancing a wave plate(32) of a winder(30) to increasing tension of the multi filament yarn; and hen winding the filament yarn.

Description

A process for preparing polyester multifilament yarns having high strength and excellent flatness and gathering properties

The present invention relates to a manufacturing method of high-strength polyester multifilament yarn having excellent flatness and focusing ability, and to a method of manufacturing high-strength polyester multifilament yarn to ensure uniformity and flatness of a low density fabric.

An air entanglement technique is a technique that causes turbulent flow parallel to the filament around the filament when the air fluid collides perpendicularly to the filament. The purpose of the air entanglement technique is not only to improve the weaving, but also to reduce the manufacturing cost compared to the flammable or sizing of filament yarn.

Generally, after fabricating polyester multifilament yarns, air entanglements are imparted at the manufacturing stage of the multifilament yarns in order to eliminate the protection process during weaving and knitting and to impart the yarn concentration. . This multifilament yarn, as shown in Figure 3, has a knot or entanglement by air entanglement, it can be divided into a notting section (1) and a non-notting section (L). In the two sections, the difference between the length of the entanglement and the thickness difference between the entangled portion and the non-entangled portion occurs, resulting in a difference in thickness during fabrication of the fabric. A coating fabric could not be obtained.

Generally, industrial polyester multifilament yarns are imparted at regular intervals by blowing air through a nozzle of an air entanglement machine to focus between each monofilament. In contrast, that is, in the notting section, strong focusing power is shown, while in the non-noting section, it is not focused. As such, when used as a coating fabric, the use of conventional air entanglements results in a large difference in thickness between the focused and unfocused portions resulting in uneven surface of the fabric.

As a result of measuring the strength and the thickness of the cross section obtained by the general air entanglement technique, 1000 denier / 192 filament yarns wound at 5.0 kgf / cm ² air pressure using an open type interlacer were used for automatic entanglement measurement. Entanglement pattern of average entangle length 140 mm, maximum knot length 800 mm, minimum knot length 50 mm, average number of entangles 5-7 pieces / m under 80 gf measurement tension in the device [Product name: Rothschild R 2070] Indicated. The average thickness of the filament yarn was 104 µm in the entangled section and 65 µm in the non-entangled section. The difference in thickness at these two points prevents the surface of the fabric from becoming uniform when weaving low density fabrics. In general, the strength and number of entanglements are controlled primarily by varying the pressure of the air and have a great influence on yarn tension and yarn speed.

In order to solve this problem, the air only in the air entanglement unit is simply used so that the difference between the entangled portion and the non-entangled portion is not clearly displayed, that is, the entanglement occurs as little as possible while showing the focusability between the monofilaments. When the pressure is lowered, the average number of entanglements decreases, the length between the minimum notes and the maximum notes increases, but the flatness of the cross section of the filament yarn cannot be exhibited, and the concentration between the monofilaments is lowered, so that the wool It was not possible to solve the problem of the occurrence of pin yarn loop and the uneven thickness during coating after weaving.

The present invention is to solve the problems of the prior art as mentioned above, while reducing the average number of entanglement, lengthening the length between the entanglement to maintain the focusing between the filaments while showing a uniform focusing force in the entangled section An object of the present invention is to provide flatness and uniformity to a fabric after coating by maintaining a flat cross section between monofilaments and maintaining uniformity until weaving.

1 is a schematic device diagram for explaining a process for producing a multifilament yarn having excellent flatness and focusability according to a preferred embodiment of the present invention.

Figure 2 is a view showing the entangled form of the multifilament yarn produced by the method of the present invention.

3 is a view showing the entangled form of the multifilament yarn produced by a conventional method.

Figure 4 is a view showing the entangled form of the multifilament yarn produced by the preferred embodiment of the present invention.

Explanation of symbols on main parts of drawing

10: 6th Goett roller 20: Air Interlacer

21: air jammer cover 22: air jammer nozzle

23: Air line 24: Regulator

25: pump 30: winder 31: pressure roller

32: Wave plate

In the method for producing a polyester multifilament yarn, as shown in FIG. 1, a cover-type air entanglement with a cover is provided immediately before winding, and the length between the guides immediately before the nozzle of the air-tight type air entangler is defined. By shortening the vibration width of the entanglement to reduce the length between the entanglement, the nozzle of the sealed air entanglement is small and the air pressure is 2.25kgf / cm ² to form weak entanglement at short intervals. As shown in Fig. 1, the nozzle of the hermetic air entanglement device is inclined about 10 ° to the heading direction and the air flow between the monofilaments achieves uniform mixing and reduces the loss of air. A cover was installed to allow monofilaments to flow in an enclosed space. Multifilament yarns manufactured by such a sealed air entanglement were able to improve the focusing of the yarn. Further, in order to maintain the focusability of the yarn when the filament yarns are wound and to flatten the cross section of the multifilament yarn, as shown in FIG. 1, an angle of 2 ° is provided between the guide roller and the nozzle in the air entanglement machine. By bending the slope, the filament tension in the nozzle is increased to keep the mixing of the individual monofilaments as small as possible by the air pressure. As the monofilament yarns that pass through the enclosed air entanglement machine are wound up, the multifilament yarns are not flattened and rounded by a traverse inside the winder.

To remedy this problem, the wave plate is advanced 20mm just before the filament yarn is wound up to the bobbin of the winder to increase the tension between the direction of filament yarn and the bobbin on which the filament yarn is wound, thereby winding the filament yarn in a flat state. It can be wound between the pressure roller of the intake machine and the winding roller.

As compared with the filament yarn manufactured by the conventional method, the cross section of the filament yarn manufactured as described above has a weaker entanglement in terms of strength of the entanglement, so that the number of strongly concentrated sections is reduced, and the entanglement that maintains the focus is increased. The shape is maintained until it passes the roller.

In addition, as shown in FIG. 3, unlike the entanglement aspect of the filament produced by the conventional method, the filament yarn obtained according to the method of the present invention, as shown in FIG. There is no section that does not have a strong part, and there is no strong part where there is a strong part. The strength of entanglement is measured by the automatic entanglement tester (Rothschild R 2070) under 80 gf tension. do. An automatic entanglement meter can measure the deviation between entanglement lengths, uniformity (CV%) and average number of entanglements. As a result of the automatic entanglement measurement of the filament yarn manufactured by the method of the present invention, the average entangled length was found to be 600 mm, and the uniformity (CV%) of the length between the entanglements was 60% ± 5%.

As shown in FIG. 2, in view of the thickness of the filament yarns, the 192 filaments are ideally arranged to have a low ratio of the diameter (b) to the height (a) of the filament.

Specific advantages and features of the present invention can be clearly seen through the following examples.

Example 1

A polyester chip having an intrinsic viscosity of 0.84 was spun at 840 denier / 192 filaments in the manufacturing method of a conventional industrial filament yarn under a spinning temperature of 290 ° C. and a spinning speed of 2800 m / min, and the device designed as shown in FIG. In the airtight air scrambler installed just before the winder and wound the filament yarns passed through the high-tension roller through the airtight air entanglement machine to the winder, where the speed of the high-torque roller 10 is 2580m / min, the speed of the winder The same or similar is maintained at 2580 ± 5 m / min, and the tension is maintained at 110 gf. In order to adjust the air pressure, an air pressure regulator (regulator) was installed immediately before the hermetic air entanglement machine, and the air pressure was wound at 2.25 kgf / cm ² . The wave plate of the winder was advanced 20 mm so that the tension of the filament yarn was increased immediately before the winding, thereby winding while maintaining flatness.

The entanglement measurement of the final multifilament yarn obtained in each example was evaluated using an automatic entanglement measuring instrument (Rothschild R 2070), and the thickness was measured using a pyrometer. The length between the entanglement of the multifilament yarns (mm) and the average number of entanglements (pieces / m) were measured using an automatic entanglement meter. In Table 1, the flatness between the filaments is judged to be good if the thickness is 72 μm or less, and the focusing property is the average number of entanglements measured by the automatic entanglement gauge tension 80gf is more than 1.5 / m and the uniformity of the length between the entanglements ( CV%) was determined to be excellent. It was determined that the filament was not flat or that the filament thickness was more than 74 µm, and that the convergence was poor when the number of entanglements was 1.5 pieces / m or less and the uniformity (CV%) exceeded 60% in the result of the entanglement measurement. . The number of times of entanglement measurement in the entanglement measuring instrument was 100 times, and the number of times of thickness measurement in the fluorometer was 30 times or more.

Example 2

In the same manner as in the spinning method of Example 1 above, spinning was carried out at 1000 denier / 192 filaments, and the air pressure of the sealed air entanglement was wound to 2.5kgf / cm ² .

Comparative Example 1

In Example 1 above, it was shown to compare the thickness and the entanglement of multifilament yarn obtained by using the open entangled without the cover of the air entangled to spun under the same spinning conditions.

Comparative Example 2

In Example 2 above, it was shown to compare the thickness and entanglement of the multifilament yarn obtained by using the open entangled without the cover of the air entangled to spun under the same spinning conditions.

Comparative Examples 3 and 4

In Example 2 above, it was shown by comparing the entanglement and thickness of the multifilament yarn obtained by spinning under the same spinning conditions, but by different air pressure of the air entanglement.

Comparative Examples 5 and 6

In Example 1 above, it was shown to compare the thickness and entanglement of the multifilament yarn obtained by spinning under the same spinning conditions, but the wave plate of the winder 20 mm than the wave plate used in Example 1.

division Denier / filament number Air crusher type Air pressure (kgf / cm ² ) Strength (g / d) Elongation (%) Average entanglement number (tension 80gf) (pcs / m) Average length between entanglement (mm) Occlusal uniformity (CV%) Focusing Thickness (㎛) Flatness Example 1 840/192 Hermetic 2.25 7.97 22.6 1.7 569 57 Great 71.0 Great Example 2 1000/192 Hermetic 2.50 7.9 22.9 1.7 592 54 Great 70.9 Great Comparative Example 1 840/192 Open 2.25 7.95 22.5 0.9 1078 66 Bad 71.6 Great Comparative Example 2 1000/192 Open 2.50 7.89 22.7 2.2 448 95 Great 78.8 Bad Comparative Example 3 1000/192 Hermetic 2.00 7.93 20.6 0.9 1135 39 Bad 68.7 Great Comparative Example 4 1000/192 Hermetic 3.0 7.92 22.8 3.2 309 68 Great 77.7 Bad Comparative Example 5 840/192 Hermetic 2.25 7.9 22.5 1.9 520 60 Great 80.0 Bad Comparative Example 6 1000/192 Hermetic 2.5 7.95 22.6 1.9 518 66 Great 82.1 Bad

As in the present invention, there is a cover, the guide is bent at an angle of about 2 °, the air pressure is 2.25kgf / cm ² at 840 denier and 1000 denier at 2.5kgf / cm ² , and the wave plate of the winder is 20 mm. By advancing, the filament yarn tension between the wave plate and the winding roller is increased to be wound so that the length between the entanglements can be maintained uniformly, and the thickness between the filaments is thin and uniform multifilament yarn can be produced.

Claims (4)

In the method of producing a high-strength polyester multifilament yarn by melt spinning the polyester polymer, passing through a high volt roller, then passing through an air entanglement to impart entanglement The high-strength polyester multifilament yarn having excellent flatness and focusability, characterized by passing the filament yarn through a closed air entanglement with a cover and advancing the wave plate of the winder to increase the tension of the multifilament yarn just before winding up. Manufacturing method. The method for producing a high strength polyester multifilament yarn according to claim 1, wherein the wave plate of the winder is advanced by 20 mm to wind the filament between the wave plate and the winding roller to increase the tension. The multi-filament yarn has an average entangle length of 500 mm or more and 1000 mm or less, an average number of entangles of 2 / m or less and a length between entanglements when measured under a tension of 80 gf using a Rothschild R 2070. A method for producing a high strength polyester multifilament yarn having excellent flatness and focusing property, wherein the uniformity (CV%) of the resin is 60% or less. The method for producing a high strength polyester multifilament yarn having excellent flatness and focusability according to claim 1, wherein the filament yarn has a thickness of 74 µm or less.