KR840002331B1 - Melt spinning method of ultrafine polyester filament - Google Patents

Abstract

Ultrafine polyester filaments are produced by melt spinning polyester filament, where the fineness of a single yarn is lower than 0.7 denier at the speed of 2500 m/min-4000 m/min under the spinning condition(I) and by cooling using a filament tank with a blower-type cylindrical cooling apparatus. I is 50 VD2/d 100, where V is spinning speed(m/min), D is diameter(mm) of outlet, d is fineness of single filament.

Description

Melt Spinning Method of Polyester Microfiber

1 is a manufacturing process schematic diagram of the present invention

2 is a cross-sectional view of an air jet apparatus used in the present invention.

1 is a detention, 2 is thread, 3 is cylindrical cooling device, 4 is air jet device, 5 is induction pipe, 6 is oil ring device, 7 is winding device.

The present invention relates to a melt spinning method of polyester microfibers having a single yarn fineness of 0.7 denier or less, and an object thereof is to provide a method for economically manufacturing continuous microfibers having excellent killing ability and good operating performance. Microfiber is a new material such as artificial leather, shovel paper, pilli, etc., and has been very much attention in recent years, and research on the manufacturing method is being actively conducted. However, when manufactured by the conventional melt spinning method, not only the bactericidal agent is poor, but also the operability at the time of spinning and drawing is extremely poor, so that a large amount of cutting is generated, making it difficult to stably manufacture the ultrafine fibers. For this reason, in order to manufacture ultrafine fibers, recently, a composite spinning of two or more components having no affinity is drawn and stretched, followed by physical or chemical treatment in a post-treatment process to separate each component or dissolve the sea component. However, in this case, a special spinning device is required, and the manufacturing process is complicated, so that the yield of the product is reduced and the manufacturing cost is increased. Thus, the present inventors have improved the conventional melt spinning method (study on the industrial method of producing microfibers with single yarn fineness of 0.7 denier or less economically and stably. As a result, such microfibers are stably For manufacturing, it was found that the discharge factor, the relationship between the spinning speed related to the spinning draft and the diameter of the discharge hole, the cooling solidification conditions of the discharge yarn, and the air resistance and tension acting on the driving yarn were important factors.

In particular, the suppression of air resistance is an important issue in the manufacture of microfibers.As the spinning speed increases, air resistance increases, which causes radiation cutting and winding tension increase. It has been found that shaking can be prevented and stable operation can be achieved under good operating conditions. In other words, the first and second quenching is done by the cylindrical cooling device that blows the cooling wind in the spinning direction as low as possible in the spinning draft as low as possible. Microfiber yarns with a single yarn fineness of 0.7 denier or less are produced by drawing them in the drawing device together with the ejecting air through the pipe, oiling them, and then drawing them to produce undrawn yarn. Can be produced. Next, the contents of the present invention will be described in detail by way of example.

1 shows an example of a spinning apparatus used in the method of the present invention, and FIG. 2 is a detailed view of the air jet apparatus. Referring to the spinning method of the present invention, the yarns discharged from the discharge hole of the detention part 1 satisfying the specified spinning conditions when producing the ultrafine multifilament having a single yarn fineness of 0.7 denier or less at a spinning speed of 2,500 m / min or more (2) passes through the high temperature atmosphere where the temperature up to 100 mm under the spinneret is kept 5-15 ° C. lower than the polymer spinning temperature, and the cooling air is moved to the inside of the yarn running direction in the cylindrical cooling device installed over the spinneret. Cooled and solidified while mounting at an angle of 30 ° to 45 ° downwards, and concentrated while being completely cooled by an air jet device 4 installed at a position of 500 to 700 mm below the spinneret. By being sent to the take-up device 7 via the ring device 6, it is possible to wind the storage force of 0.5 g / or less even at a high speed of 2,500 m / min or more, and the undrawn yarn manufactured here is 1.5 to 2.5 in a conventional drawing machine. Boat stretch As it can produce economically stabilizing the superfine fiber.

In the case of spinning the microfibers by reducing the discharge amount in the conventional melt spinning apparatus, the output amount of the sugar must be 0.3 g / min or less in order to obtain microfibers having a single yarn fineness of 0.7 denier or less. However, in this case, the discharge amount changes in each furnace construction, so that in severe cases, dropping occurs, and the bactericidal system is poor, and operationability is extremely deteriorated. At this time, the spinning draft becomes 200 or more, so that uneven unstretched yarn is obtained due to the rapid cross-sectional change, and the residual elongation is reduced due to excessive molecular orientation in the spinning, so that the draw ratio is lowered to achieve the purpose of producing ultrafine fibers. Here, the most stable spinning is possible by setting the spinning draft within the range of 100 to 150 by adjusting the discharge hole diameter to 2,500 to 4,000 m / min and adjusting the discharge hole diameter as conditions for increasing the discharge amount per empty and lowering the spinning draft. Thus, the present inventors found that the spinning condition is good and the bactericidal agent is uniform under the spinning conditions satisfying the following equation.

In this equation, if the value of d / VD ² is less than 50, the ejection hole is too small, so even if there is slight variation in the precision of the machining, the cross-sectional change between single yarns becomes larger, and the detention is difficult. ^When the value of ² exceeds 100, the discharge hole becomes large and the radiation draft increases, so that the radiation is easy to occur in the deformation area, and the microbial system becomes uneven due to the non-uniform deformation, resulting in poor operation. In addition, since the molecular orientation develops as the radial draft increases, the residual elongation is lowered and the draw ratio is lowered. In order to obtain finer detail, increasing the draw ratio is one method. For this purpose, a temperature of 5 to 10 ° C. higher than the normal spinning temperature and a temperature of 100 mm below the spinneret are 5 to 15 ° C. lower than the radiation temperature to alleviate highly oriented molecular alignment. You will get better results.

When the spinning speed is more than 2,500m / min, the radiation tension increases, and this phenomenon increases significantly as the air contact area of yarns increases and the radiation length increases, causing severe shaking and affecting the deformation area. It is easy to cause truncation. In addition, the winding tension is increased due to the increase in the radial tension, the winding form is poor, which interferes with the stretching process, resulting in poor operability.

Therefore, in high-speed radiation, radiation tension is an important factor for operational stability, and it is necessary to adjust this radiation tension low. In order to solve this problem, the inventors

First, by installing a cylindrical cooling device over 100 ~ 30mm under the spinneret, it is possible to reduce the air resistance acting on the thread by blowing the cooling wind 30 ~ 45 ° inward and downward in the direction of thread movement.

Second, install the air jet device at 500 ~ 700mm position under the spinneret to cool the thread and connect it to the take-out device through the induction pipe together with the ejection air to lower the radial tension below 0.15g / d. It turned out that the better.

In particular, in the present invention, the angle of cooling wind of the cylindrical cylinder cooling device is to be 30 to 45 ° inward downward with respect to the running direction of thread. If it is less than 30 °, the cooling wind contact point for the thread moves downward and the freezing point is lowered due to insufficient cooling, which causes fusion and collision between the yarns, causing radiation loss, and also causing severe shaking in the deformation zone. On the other hand, if the temperature is greater than 45 °, the cooling winds may be disturbed, resulting in unstable threading, which may lead to deterioration of the operating conditions and reduction of friction with the accompanying airflow. Air jet devices used for the purpose of cooling connection of thread must be installed at 500 ~ 700mm below the spinneret. If the position is smaller than 50mm and it is too close to the detention, because the cooling solidification of the thread is insufficient, the convergence occurs easily between the threads, and the focusing angle is increased, so that the friction between the thread introduction part and the thread of the air jet device increases. The tension increases and affects thread thread, resulting in increased cutting.

In addition, when the position is 700 mm or more, the contact area between the multifilament and the air increases, which is not good because the air resistance increases. In this way, the non-expanded yarn with residual elongation of 120 to 240% at a spinning speed of 2,500 to 4,000 m / min is supplied by lubricating the focused multifilament through the induction pipe with a conventional oil ring device and winding the anti-tension under 0.15 g / d. It can be obtained by stretching 1.5 to 2.5 times in a conventional drawing machine, and it is possible to produce a polar fine filament of less than 0.7 Ni in single yarn fineness in good operating conditions.

The model of the air jet apparatus used for the spinning apparatus of this invention is shown in FIG. In the figure, the air drawn in through the air inlet 4a is adjusted so that it is not swirlable in the dispersion plate 4b, and then becomes a high-speed jet air through a small interval to suck the thread from the threaded inlet 4c to eject the outlet 4d. Eject through. The air supplied to this air jet apparatus is a high pressure air of ² to 5 kg / cm ² , and can be applied up to a spinning speed of 5,000 m / min.

The air jet apparatus used in the present invention has a specification of an inlet diameter of 3 to 5 mm and an inlet diameter of 4 to 6 mm, and an angle of inlet nozzle angle θ ₁ and an air spray angle θ ₂ in the nozzle are 30 to 40 ° with respect to the thread running direction, respectively. , 5 to 15 degrees are suitable.

Hereinafter, the present invention will be described in detail with reference to Examples.

EXAMPLE

Using the spinning apparatus shown in FIGS. 1 and 2, the pulley ester having an intrinsic viscosity (ortho chlorophenol measurement) of 0.65 at 25 ° C. was spun at 295 ° C. using a discharge hole of 72 and a detention diameter of 100 mm. Conditional draw ratio, results are as shown in FIG. In addition, the cooling conditions were set and tested as follows.

(1) Cooling air blowout inner diameter -130mm

(2) cooling air outlet surface length-200mm

(3) Cooling device installation location-100mm under the spinneret

(4) Cooling wind temperature -19 degrees Celsius

(5) cooling wind velocity-0.34 m / sec

The result was a product with very good radioactivity, stretching and leveling.

TABLE 1

Comparative Example 1

Spinning speed, discharge diameter, cooling airflow angle, air of polyester with intrinsic viscosity (measured at 25 ° C. ortho chlorophenol) 0.65 using a spinning device such as in Example The jet device position was spun at 295 ° C. while changing as shown in the second table. Cooling conditions were the same as in the examples.

As a result, a product having poor elongation and uniformity due to radioactive defects was obtained.

TABLE 2

Comparative Example 2

Using a conventional melt spinneret, a polyester with an intrinsic viscosity (measured at ortho chlorophenol at 25 ° C) of 0.65 was used to obtain a discharge amount, spinning speed, and draw ratio through a mold with a discharge hole diameter of 0.23 mm, a discharge number of 72, and a cage diameter of 100 mm. It was spun at 290 ° C. while changing as shown in Table 3. Cooling was tested under the following cooling conditions as a transverse chiller.

(1) Cooling air blowout inner diameter -130mm

(2) cooling air outlet surface length-900mm

(3) Cooling device installation location-150mm under the spinneret

(4) Cooling wind temperature -19 degrees Celsius

(5) cooling wind velocity-0.34 m / sec

As a result, the drawability and the bactericidal agent were very poor due to the radioactive defect.

TABLE 3

Claims (4)

In the spinning of microfine fibers having a single yarn fineness of 0.7 denier or less by the spinning method at a spinning speed of 2,500 m / min -4,000 m / min, the molten spinning is carried out to the discharge hole of the cap which satisfies the following formula, and then blown from the bottom of the spinneret. A melt spinning method of microfiber with polyester for cooling a yarn tank with a cylindrical cooling device and then focusing the yarn with an air jet device at the bottom thereof.

The method according to claim 1, wherein the blown cylindrical cooling device is installed at a lower position of 100mm-300mm of the spinneret. The method of claim 1, wherein the air jet device is installed at the lower 500mm-700mm position of the spinneret. The method according to claim 1 or 2, wherein the cooling air is blown inwardly downwards from 30 ° to 45 ° with respect to the yarn movement direction.

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