KR100553394B1 - Polyethyleneterephthalate Semi-oriented filament and process of producing thereof - Google Patents

Abstract

The present invention relates to the production of a novel partial alignment yarn having a low heat shrinkage rate using a cylindrical cooling air distributor to which an out-in cooling method can be applied. In addition, according to the present invention, a very good yarn can be obtained, and since only 40% of the cooling air flow is sufficient compared to the existing cooling method, cost reduction effect can be obtained at the same time.

Description

 Polyethylene terephthalate partially oriented yarn and its manufacturing method {Polyethyleneterephthalate Semi-oriented filament and process of producing}             

  1 is a cross-sectional view of a cooling apparatus used in the present invention.

* Description of the signs in the drawings

1: Cooling air distributor 2: Punching plate

3: nonwoven filter 4: candle

5: heat insulating material 6: spinneret

  In general, in order to manufacture a synthetic fiber through melt spinning, the filament is formed by applying heat to a synthetic resin capable of forming a fiber, and then pushing it at a high pressure through detention. At this time, if the filament produced through the detention is not uniformly cooled, the solidification point is different for each filament, and there is a difference in thickness for each monofilament.

  Therefore, in order to solve this problem, it is necessary to cool the monofilaments uniformly by using a cooling device during the spinning process. In this case, the cooling medium used is mainly air or water. As a result, fibers having uniform physical properties and improved leveling agent can be obtained.

     Cooling method commonly used in melt spinning process is largely cross-sectional cooling

It can be divided into -flow quenching method and circular quenching method, and the single-sided cooling method is one-side and both-side cooling again, and the circulating cooling method is out-in. And centrifugal type (In-out).

  The single-sided cooling method uses a box-type cooler to blow uniformly cooled air from one side of the molten polymer to cool the polymer by forced cooling by air exhaust, which can be divided into one-sided and double-sided cooling. . Sectional cooling is the most common method of blowing the cooling wind in the vertical direction to the yarn bundle. As the new air is slowly and continuously supplied, a uniform interface is formed and the thread is constantly cooled. However, if the thickness of the short fibers is very thick or the number of the short fibers is large, a cooling car is placed in the area where the cooling wind directly touches and vice versa. To produce uneven threads. Therefore, it is not suitable for the production of special products, but in the case of general companies, it is most widely used as a method for producing yarn at the most efficient and low cost.

  When the thickness of the short fiber is very thick compared to the general yarn or the number of short fibers is large, the cooling device is installed on the front side besides the rear side to cool the yarn on both sides. In this case, the cooling efficiency is superior to the one-sided cooling method, and since the cooling deviation disappears a lot from the front and rear parts of the thread bundle, it is possible to make the thread to a certain degree, but the installation is complicated and the equipment cost and cooling wind consumption are increased.

  Centrifugal (In-out blow) cooling method is to insert a cylindrical cooling device in the middle of the fiber bundle and blow out the cooling wind to the outside. This method has the advantage of excellent cooling efficiency and excellent sealant, but the cooling device should be located at the center of the detention, so the new detention must be radially designed to have a high hole density in a small area. It is expensive and has a lot of administrative difficulties.

  Out-in blow cooling is a method that blows cooling winds around the emitted fiber bundle by surrounding the cylindrical cooling device, which is very advantageous for the production of yarn with a large number of short fibers. Even when the spinning speed is low, there is an advantage that a partial alignment yarn having a low form stability with low thermal shrinkage can be manufactured.

In general, when the partial alignment yarn is manufactured by using a single-sided cooling method, a fiber having a heat shrinkage of about 50 to 60% can be obtained at a spinning speed of 3,300 m / min or less, and a fiber having a heat shrinkage of 10% or less is obtained at a 4,500 m / min or more. Can be. However, at spinning speeds of 3,000 to 4,500 m / min, thermal shrinkage is not constant up to 10 to 50% and very non-uniform fibers are obtained. Therefore, in general, partial alignment yarns with high heat shrinkage are manufactured at the speed of 3,300m / min or less, but they are often used as composite yarn materials. There exist problems, such as a dyeing difference. On the other hand, partial alignment yarns manufactured at spinning speeds of 4,500m / min or more have heat shrinkage of less than 10%, but they have limited stability because they can not secure facility constraints and desired levels of elongation.

Therefore, the present invention is almost similar to the partial orientation yarn manufactured by the one-sided cooling method using a cylindrical cooling device that can apply the out-in cooling method, the heat shrinkage is less than 10% and excellent in shape stability It aims to manufacture a new partial alignment yarn. In addition, the partial alignment yarn prepared in this way is very good uniformity.

Therefore, in the present invention, in the polyethylene terephthalate partial alignment yarn,

A polyethylene terephthalate partially oriented yarn is provided, characterized in that the short fiber fineness is 0.3 to 10 denier, the elongation is 80 to 140%, and the specific shrinkage is 10% or less.

In addition, in the manufacturing method of the polyethylene terephthalate partial aligning yarn, formed in the cooling air distributor, the molten filament is passed through a plurality of candles connected to the inlet of the spinneret through which the molten filament is discharged, and surrounding the filament Provided is a method for producing a polyethylene terephthalate partially oriented yarn, characterized in that the filament is cooled by a cooling wind drawn in the reverse direction of the filament discharge direction.

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

In the present invention, the molten filament is passed through the plurality of candles connected to the inlet of the spinneret discharged, and the filament is cooled by the cooling wind introduced around the filament in the reverse direction of the filament discharge direction do.

1 is a schematic view of a cooling apparatus used in the manufacturing method of the present invention. Generally, the out-in cooling method using a cylindrical cooling device is a method commonly used in the manufacture of filaments by the melt spinning method, but in general, it is applied to a lot of equipment in which one detention unit is installed in one pack. It is common to have separate lines for supplying cooling air to each pack.

However, in the present invention, it is characterized in that the cooling air distributor is installed to uniformly deliver the cooling air to a plurality of candles in one cooling air line, and to increase the uniformity of the cooling in the cooling air distributor 1 of 3mm in diameter A punched porous plate (2: Punching plate) and a nonwoven filter (3) were inserted and used.

In addition, the upper portion of the candle (4: Candle) was installed to control the heat transmitted from the high temperature spinneret (6) by installing a heat insulator (5), the material used for the insulation is ceramic, Teflon, gypsum, ceramic Board etc. The physical properties of filament yarns such as elongation, NDR, uniformity, cross section and the like greatly change depending on the thickness of the heat insulating material. Therefore, in order to manufacture the filament yarn having excellent quality, it is important to maintain an appropriate hot zone by selecting a heat insulating material having an appropriate thickness. In the present invention, the hot zone is about 10 to 120 mm. It is good to keep about 15mm ~ 80mm.

Looking at the candle (Candle) that is the cooling device in detail as follows. Candles, which are cylindrical cooling devices, can be made of sintered metal and those made of cellulose using phenolic resin. The latter has a light advantage, but the impact strength is weak and the replacement cycle is short. On the other hand, although the initial production cost is somewhat high, it can be used semi-permanently, and since it is easily cleaned by ultrasonic cleaning at the time of cleaning, it is preferable to use one made of sintered metal. The size of the candle used was 100mm to 600mm in length, preferably 200mm to 400m. If the length of the candle is less than 100 mm, the amount of cooling air is insufficient, so that the polymer discharged from the spinneret is not sufficiently solidified, resulting in irregular cross-sections, resulting in a very poor filament yarn, whereas the length of the candle exceeds 600 mm. In this case, the cooling wind consumption is excessively wasted, and equipment costs are high. If the discharge amount is less than 40g / min, the length of the candle is preferably about 250mm.

In addition, the candle was used to have a mesh of about 30 ~ 70㎛, the difference in the physical properties of each mesh was not very large, but how evenly distributed the holes of the candle had a greater influence on the physical properties. .

The distribution of the cooling winds introduced through the cans differs according to the positions of the cans, and most preferably, the upper discharge speed is greatest and becomes weaker toward the lower side. The upper wind speed should be maintained at 0.5 m / s to 3.0 m / s, the middle part at 0.3 m / s to 2.0 m / s, and the lower part at 0.1 m / s to 1.0 m / s, most preferably. Most preferably, the upper wind speed is 0.3 m / s to 1.0 m / s, the middle part is 0.2 m / s to 0.5 m / s, and 0.1 m / s to 0.4 m / s. In general, using a sintered metal with a mesh of 30 to 70 μm results in the highest wind speed at the top of the candle and the weakest at the bottom without any special equipment or methods. If wire mesh or the like is used outside the candle, the wind speed can be artificially adjusted according to the area of the candle, and the uniformity and heat shrinkage of the manufactured filament are slightly changed depending on the wind speed, but it is not a level that affects the properties of the yarn.

When the wind speed is small, the filament yarn is reduced due to insufficient cooling wind due to the uneven solidification, and when the wind speed is large, there is a lot of noise in the candle, and the yarn is also bad.

When the partial alignment yarn is manufactured by the out-in cooling method by the cooling wind drawn in the opposite direction of the filament discharge direction by using the cooling air branch having the above candle, the shape shrinkage is low due to the low heat shrinkage even at the low spinning speed. This excellent yarn can be obtained. In general, when the polyester partial alignment yarn is manufactured by cross-flow cooling, a yarn having a relatively uniform heat shrinkage of about 50 to 60% at a spinning speed of about 3,300 m / min can be obtained and 5,000 m. A yarn having a uniform heat shrinkage of 10% or less at / min or more can be obtained. However, between 3,300 and 5,000 m / min of spinning speed, thermal shrinkage is not constant and yarns varying very unevenly up to 10 to 50% are obtained, which may be attributed to the orientation behavior of polyethylene terephthalate according to spinning speed.

In general, polyethylene terephthalate has a structure in which the molecular chains are not oriented in the fiber axis direction and the crystal regions are not grown yet at low spinning speeds (below 2,000 m / min). do. Therefore, the unstretched yarn produced in the low flux region has a low orientation and low crystalline structure and thus cannot be stored for a long time and has difficulty in processing due to excessive necking phenomenon during stretching. Therefore, in general, partial alignment yarns that emit spinning speeds of about 3,000 to 4,000 m / min are mainly used, which are characterized by higher orientation than undrawn yarns, but have high elongation compared to stretched yarns and have high heat shrinkage. Not only there is a problem such as embrittlement in the process, but also due to the difference in the dyeing behavior with the drawn yarn there is a problem that the tone difference occurs in the fabric.

In addition, the fiber spun at a spinning speed of 6,000 m / min or more has a high crystallization and high orientation structure. First, the crystallization and necking phenomenon on the radiation are closely related to each other. Crystallization is caused by the high stress within a very short time on the radiograph, which leads to a sharp increase in the degree of orientation of the amorphous region, which shows a different structure and mechanical properties than the large number of small crystals of elongated fibers in slow spinning. The necking occurs when crystallization occurs on the radiation. The elongation viscosity increases along the radiation, and localization decreases at any point due to the crystallization exotherm, and then the viscosity is rapidly increased again to complete the thinning behavior.

Second, there is a difference in the structure inside and outside the fiber. The fibers stretched after spinning at low speed have no structural difference in cross section, but also show higher birefringence inside than the surface due to heat from the fiber surface during stretching. Fast-spun fibers, on the other hand, have a higher surface birefringence than the interior and have a distinct skin-core structure. Therefore, the fiber produced by the high-speed spinning is less thermal shrinkage than the partial alignment yarn, but the shape stability, but compared to the drawn yarn, the elongation is somewhat high, so the use is limited. And the fiber produced by the high-speed spinning has the properties of the stretched yarn only by the spinning process, but the molecular orientation is not very good compared to the fiber produced through the two stages of the traditional spinning-stretching.

On the other hand, in the present invention, it is preferable to produce at a spinning speed of 2,500 ~ 4,000m / min. The elongation of the partially oriented yarns manufactured in this way is almost similar to that of the yarns produced by the conventional single-sided cooling method, but a very high form stability yarn can be obtained with a non-shrinkage rate of 10% or less. This is because it cannot be released to the outside and can only escape to the bottom of the candle, which results in a severe air drag, thus increasing the radial tension and increasing the orientation of the radial fibers. This can be confirmed that the birefringence of the yarn produced by the out-in blow cooling is larger than the yarn produced by the cross-sectional cooling method at the same flux.

In the present invention, it is preferable to spin the filament through the number of detaining spinnerets of 12 to 384. If the number of detaining prisoners is 12 holes or less, the air shrinkage caused by the fiber bundle is weakened, so the effect of low shrinkage decreases a lot. . On the other hand, in the case of more than 288 holes, the desired heat shrinkage can be obtained, but there is a problem that the uniformity is considerably poor . For this reason, the greater the odd number of detention, the greater the low heat shrinkage effect with excellent shape stability.

 In addition, the uniformity of the yarn produced by the cooling method of the present invention is very excellent, which is due to the short distance between the blow zone (B / D) and the hot zone compared to the general cross-sectional cooling method. B / D is the distance from the candle to the outermost hole of the detention, which acts as the cooling of the filament. In general, the single-sided cooling method has a distance of about 100 mm between the cooling system and the thread, so that the supplied cooling wind does not effectively affect the yarn, and the amount of cooling wind that is wasted into the space other than the bundle of yarns increases the efficiency of using the cooling wind. Will fall. However, the cylindrical cooling method according to the present invention can keep the B / D and the hot zone short, greatly improving the uniformity of yarn, and use all of the cooling air supplied without solid waste of cooling air to solidify the filament. It is possible to obtain a yarn having good quality even with about 40% of the cooling air volume compared to the cooling method, and at the same time can reduce the cost.

According to the production method of the present invention, a polyethylene terephthalate partial alignment yarn can be obtained, characterized in that the short fiber fineness is 0.3 to 10 denier, the elongation is 80 to 140%, and the specific shrinkage is 10% or less. Although there is no crystal, it has high elongation and high non-shrinkage ratio, so it can be used for fabrics including artificial suede. Especially, it can be used for casual and women's blouses in combination with drawing yarn.

The following examples are given as non-limiting examples of producing the polyethylene terephthalate partial alignment yarn of the present invention.

Example 1

The polyethylene terephthalate partial alignment yarn having excellent shape stability was manufactured using the cooling apparatus of FIG. The spinneret was made of yarn with a single fineness of 1.0 denier using 72 holes, and the wind speed was 0.4 m / s and the spinning speed was 2,500 m / min. The properties of the prepared polyethylene terephthalate partial aligning yarn is measured in the following manner and shown in Table 1 together with the following examples and comparative examples.

* Thermal Shrinkage (BWS): Wind the sample 20 times using wrap reel according to the standard of K 0215-1982, load the single yarn fineness x 2 times, and measure the initial length on the scale plate. The exact first length of the sample is wrapped in gauze, placed in an iron box and placed in a 100 ° C hot water bath. Remove the heat treated sample from the bath for 30 minutes, cool it naturally, remove the water, mark the sample again on the scale plate, apply the weight of 2 times the single yarn fineness, read the reduced length, and record the following equation. Calculate the heat shrinkage rate by 1.

[(First Length Before Hot Water (L0)-Later Length After Hot Water Heat Treatment (L1)) / (First Length Before Hot Water (L0))] × 100 ------------ Equation 1 )

* Elongation: In accordance with the standard of KS K 0409, the thread is bitten into a jaw having a certain gauge length (200mm), and the thread is pulled at a tensile speed of 720mm / min until the thread breaks. Obtain (Device name: Zwick 1510 (UTM))

[(Extended length) / (gauge length)] × 100 ----------- Equation 2)

* Bacterial system: In accordance with KS K 0467 standard, Keisokki's Evenness Tester (Model KET-80C) is used to measure the uniformity. Measure the leveling system.

EXAMPLE 2 It is the same as Example 1 except the spinning speed being 3,000 m / min.

EXAMPLE 3 It is the same as Example 1 except the spinning speed being 3,500 m / min.

EXAMPLE 4 It is the same as that of Example 1 except the spinning speed being 4,000 m / min.

EXAMPLE 5 It is the same as that of Example 1 except having set the wind speed to 0.6 m / s.

EXAMPLE 6 It is the same as Example 2 except having set the wind speed to 0.6 m / s.

EXAMPLE 7 It is the same as Example 3 except having set the wind speed to 0.6 m / s.

EXAMPLE 8 It is the same as Example 4 except having set the wind speed to 0.6 m / s.

COMPARATIVE EXAMPLE 1 It is the same as Example 1 except not having used the cooling apparatus of FIG.

COMPARATIVE EXAMPLE 2 It is the same as Example 2 except the spinning speed being 3,000 m / min.

COMPARATIVE EXAMPLE 3 It is the same as Example 3 except having made spinning speed 3,500 m / min.

COMPARATIVE EXAMPLE 4 It is the same as Example 4 except having made the spinning speed into 4,000 m / min.

Short-fiber fineness (Denia) Cooling method Spinning speed (m / min) Shinto Non-shrinkage rate (%) Leveling system Example 1 One Centrifugal Cooling Method 2,500 158 11 0.99 Example 2 One " 3,000 128 10 0.92 Example 3 One " 3,500 102 6 0.99 Example 4 One " 4,000 95 5 1.02 Example 5 One " 2,500 156 9 0.89 Example 6 One " 3,000 129 8 0.85 Example 7 One " 3,500 100 4 0.95 Example 8 One " 4,000 94 3 0.93 Comparative Example 1 One Single side cooling method 2,500 160 60 1.25 Comparative Example 2 One " 3,000 130 58 1.21 Comparative Example 3 One " 3,500 105 50 1.32 Comparative Example 4 One " 4,000 95 15 1.37

Therefore, according to the present invention, the elongation is almost similar to that of the partial alignment yarn manufactured by the cross-sectional cooling method, but the heat shrinkage is 10% or less, so that the new partial alignment yarn having excellent shape stability can be manufactured to have excellent uniformity.

Claims (5)

In the manufacturing method of the polyethylene terephthalate partial alignment yarn, Two or more candles of a cooling air distributor connected to the spinneret, having a heat insulating material between the spinneret and the candle mouth, having a sintered metal candle having a length of 100 to 600 mm therein, and having a perforated plate and a nonwoven filter at the bottom thereof. A method of producing a polyethylene terephthalate partially oriented yarn comprising: passing a molten filament therein and cooling the filament with a cooling wind drawn in the opposite direction of the filament discharge direction while surrounding the filament in the candle. delete The method for producing a polyethylene terephthalate partially oriented yarn according to claim 1, wherein the number of detaining spinnerets is 12 to 384. The method according to claim 1, wherein the spinning speed is 2,500 to 4,000 m / min.  The polyethylene terephthalate partially oriented yarn prepared according to claim 1, wherein the short fiber fineness is 0.3 to 10 denier, the elongation is 80 to 140%, and the non-shrinkage rate is 10% or less.

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