JPS636106A - Melt spinning method - Google Patents

Abstract

PURPOSE:To prevent the breakage of single filaments in high-speed melt-spinning through multi-orifices, by surrounding at least the front and back sides of the filaments with plates at a place nearly just above a bar oiling device, wherein said plates are inclined from each other in such a manner that the plates approach the filaments toward the bar of the oiling device. CONSTITUTION:Melt-spun and then asymmetrically quenched filaments 2 are oiled with a bar oiling device equipped with plates 4 for guiding accompanying gas flow. The plates for the guiding plates may be flat or curved. The guiding plates equipped just above the oiling device rectify the accompanying gas flow along the filaments in the take-off direction of the filament preventing the separation of the accompanying gas flow from the filaments. Consequently, the guiding plates prevent the increase in the frequency of breakage of the single filaments caused by the increase in the take-off speed of the filaments.

Description

[Detailed description of the invention] Industrial application field> The present invention is directed to so-called asymmetric quench spinning, in which a cooling air stream is blown from one direction onto a spun yarn of a thermoplastic polymer, particularly polyester or boriabad. The present invention relates to a spinning method that allows stable spinning and winding by properly handling accompanying airflow.

<Conventional technology> In recent years, with the advancement of spinning technology, the spinneret has been made more porous and the take-up speed has been increased as a measure to improve equipment productivity. New problems are arising as a result. That is, under such conditions, spinning and winding become unstable, so asymmetrically quenching fibers with irregular cross sections or hollow cross sections,
When a spinneret having 400 or more pores is used in a method of spinning at a high speed of 3000 m/min or more, spinning and winding become extremely unstable. The present inventors have discovered that the cause lies in the accompanying airflow. That is, as the take-up speed becomes higher than 3000 m/min, the speed and flow rate of the accompanying airflow increase.
Yarn breakage, winding, or other negative effects on quality may occur during the spinning and winding processes.In addition, when the number of holes exceeds 400, the flow rate of accompanying airflow increases significantly, causing disturbances in the spinning and winding conditions. do.

In addition, as a method of applying oil agent in conventional melt spinning,
1) A method of applying an oil agent by running a yarn in contact with the surface of a rotating roller whose part is immersed in an oil agent, and ii) using a V-shaped guide having pores in the bent portion for supplying the oil agent. There is a method of pressing the traveling yarn against the pores and causing the flowing oil to adhere thereto.

When method i) is used, as the number of holes increases to about 400 or more, the speed or flow rate of the accompanying airflow increases, resulting in problems such as scattering of the oil, spots of oil adhesion, or problems with spinning. It is necessary to focus the yarn using a focusing guide between the mouthpiece and the lubricant application device, but the
A take-up speed of 0 yyt/min or more is undesirable because single yarn fuzz is likely to occur due to friction between the yarn and the guide. In the case of method I:), if the number of filaments is 400 or more, the yarns will concentrate at one point at the figure-7 bend, resulting in fused yarns or from the holes on the outer periphery of the spinneret. There are problems such as the tension of the spun yarn increases and single yarn breakage occurs frequently. In view of these circumstances, the present inventors have developed a melt spinning method that eliminates these drawbacks and can operate stably, using an oil applying device with a width of 0.05 to 0.3.
He discovered a melt spinning method characterized by using a rod-shaped oiling device having at least one linear slit, and has already filed a patent application (Japanese Patent Application No. 60-28933).
issue).

In this case, it is preferable that the rod-shaped oiling device is installed so as to be perpendicular to the running direction of the yarn, and that two oiling devices are used so that the oiling agent is evenly applied. However, the take-up speed is 3500.7 minutes or more, especially 3800.
m/min or more, one or two single yarns may jump out from the rod-shaped oiling guide in the oiling section, causing single yarn breakage or roller winding, making winding difficult. As a result of detailed observation of this phenomenon by the present inventors, it was found that the accompanying airflow was the main cause in this case as well. In other words, since the two rod-shaped oiling guides uniformly apply the oil to both sides of the yarn, the accompanying airflow is squeezed out by the guides, and the take-up speed increases to 3,500 m/min or more, especially 3,800 m/min or more. Then, one or two single threads fly out from the rod-shaped guide along with the accompanying airflow that is squeezed out.

<Problems to be Solved by the Invention> In view of these circumstances, the present inventors have conducted extensive research into a melt spinning method that can be stably operated without single fiber breakage in a porous and high speed spinning method. This led to the present invention.

<Means for Solving the Problems> The present invention involves melt-extruding a thermoplastic polymer through the pores of a spinneret having 400 or more pores, applying cooling air to the formed yarn, and extruding it into a rod-shaped object. A lubricant is applied to the yarn by bringing the yarn into contact with a provided oil supply slit, and 3
In a melt spinning method in which the yarn is taken up at a speed of 000□/min or more, at least the front and back sides of the yarn are tilted almost directly above the rod-like object so that the closer the rod-like object, the closer to the yarn the yarn is. This is a melt-spinning method characterized by surrounding the fibers with a plate-like material (hereinafter referred to as a guide plate) having That is, in the present invention, a thermoplastic polymer is melt-extruded from a spinneret having 400 or more pores, cooled by cooling air, applied with an oil agent by a rod-shaped oiling device, and synthesized by taking it off at a high speed of 3000 m/min or more. In order to obtain fiber threads, an enclosure is installed directly above the oiling device to rectify the accompanying air flow, and spinning is performed.

Conventionally, when picking up yarn at a high speed of 3000 m/min or more,
When applying the oil to the yarn, the oil is blown off by the accompanying airflow, so there are problems such as the oil scattering and difficulty in uniformly applying the oil to the yarn.
As described in Japanese Unexamined Patent Publication No. 57-199807, a method has been adopted in which the accompanying airflow is completely stripped off from the yarn and an oil agent is applied. However, in the present invention, a guide plate is provided directly above the oiling part, and the accompanying airflow is not separated from the yarn, but rather is rectified and flows along the yarn in the take-up direction, which is different from the above-mentioned known method. are fundamentally different in thought and concrete means.

Although the object of the present invention can be achieved by providing the guide plate as described above, it is more preferable to satisfy the following conditions. In other words, when carrying out asymmetric quench spinning, the length of the guide plate and the height of the guide plate in the direction parallel to the yarn, as shown in FIG. When cut in a plane perpendicular to the running direction of the yarn, the cutting area (S') of the entire yarn as shown in Figure 4 and the cross-sectional area (S') of the guide plate It is preferable that the oiling device in which the guide plate is installed satisfies the following equations (1) to (5).

(1) y+2≦x≦y+10 (2) 0.004H≦y≦0.04H (3) 2≦2
≦30 (4) 1.5≦S/S'≦10 However,
(See C)) y: Length of slit of #-shaped oiling device crIL)
2: Height of the guide plate in the direction parallel to the filament shape / Cross-sectional area of the entire yarn when cut in a plane perpendicular to the running direction of the yarn (CR S: When cut in a plane perpendicular to the running direction of the yarn with the uppermost hook of the guide plate Cross-sectional area of the guide plate removed (ml) l: Distance from the spinneret to the slit t of the rod-shaped oil ring (α) In addition, if the values of X and Z are different between the two guide plates before and after, the The larger value is adopted.Also, if the position of the top end of the guide plate is different between the front and rear guide plates,
The shape of the top end of the lower guide plate is extended parallel to the yarn to the top end of the higher guide plate, and the shape is surrounded by this extended top end shape and the top end shape of the higher guide plate. Let the area of the area be S (see Figure 5 (c)).

In the present invention, the length of the slit of the rod-shaped guide is 0.0.
If the length is shorter than 0.04Hm, and the number of nozzle holes is 400 or more, which is what the inventors are aiming for, single yarn fuzz will easily occur in the rod-shaped guide portion due to uneven adhesion of the oil agent or excessive tightening of the yarn. On the other hand, if the length of the slit is longer than 0.04 Hα, it will be difficult for the oil to adhere uniformly, and the oil will scatter. Note that the slit length is usually the same as or about 2 to 3 u larger than the yarn width at the slit portion. In addition, if the guide plate is not longer than the length of the slit of the rod-shaped guide by 1) 2 crn or more, it will be affected by the accompanying air current and single thread breakage will easily occur. Because there are many characters, it becomes unnecessary length. In addition, there is a possibility that the accompanying airflow escapes in the direction perpendicular to the running direction of the yarn, and the single yarn follows along with it, jumping over the jig that fixes the oiling device and causing single yarn breakage. . In particular, as a measure to prevent the yarn from jumping out in the lateral direction, guide plates are installed on the left and right sides as shown in (b) in Figure 3, and a set of four plates are used, and the running yarn is used as shown in e→ in Figure 3. The thread is cut in a plane perpendicular to the running direction of the thread φ. There are some that have a similar shape to the cross section of the whole, with a slit at the oiling position.Next, the height Z of the guide plate (see Figures 5 (a) to (c)) is shorter than 2 cIL. The effect is low, single yarn breakage occurs, or winding occurs on the roller, making stable winding difficult. Moreover, if it is longer than 30fi, it will conversely collect accompanying airflow, and the oiling part will be more likely to have spots of oil adhesion. In addition, as shown in Figures 3 and 4, the 0-cut cross-sectional area (S') of the entire yarn when cut in a plane that includes A A' at the top end of the guide plate and is perpendicular to the traveling yarn and the guide In the relationship between the cross-sectional area (S) of the plate, S/S' is 1.5
It is preferable that ≦S/S'≦10, and when S/S' is smaller than 1.5, the yarn tends to come into contact with the guide plate, and fuzz and single yarn breakage are somewhat likely to occur. Also, when S/S' is larger than 10, the accompanying airflow is collected and the yarn swings become large), the oil agent adheres unevenly, the spinning becomes somewhat unstable, and the quality is also adversely affected. .

Next, the oiling position does not cause solidification in the thread running direction, which increases unevenness in the fineness of the thread, but also makes it more likely that fused threads will occur, resulting in a decrease in quality and spinnability. In addition, the amount of oil increases and excessive spinning tension is applied, which tends to cause single yarn breakage, leading to a decrease in operability.

In addition, in the present invention, there is no large gap between the rod-shaped oiling guide and the guide plate provided directly above it, as shown in Figures 2 and 5, in order to prevent disturbances in the accompanying airflow. It is preferable. If there is a distance between the two,
As shown in FIGS. 3(c) and 3), in order to prevent new intrusion of accompanying airflow as much as possible, a new plate-like object 16 is installed between the two, especially so as to surround at least the front and back sides of the yarn. It is preferable to provide one.

Next, details of the present invention will be described using the drawings.

These drawings are merely examples of the present invention, and the present invention is not limited thereto. (a) in Figure 1
(b) shows the state of the pore arrangement of the spinneret used in the present invention, and the pores are arranged on a plurality of parallel lines. By applying cooling air to the yarn from a direction perpendicular to these parallel lines, uniform asymmetrical rapid cooling can be performed regardless of whether it is upwind or downwind, even if it is a yarn with an irregular cross section or a hollow fiber. becomes. FIG. 2 is a schematic diagram showing an embodiment of a spinning take-off device used in the present invention.

The yarn 2 discharged from the spinneret 1 passes through a cooling zone 3, is cooled and solidified, and then comes into contact with a rod-shaped oiling device R5 provided with an accompanying airflow guide plate 4, and is coated with an oil agent. In this case, two oiling guides are used to ensure that the oil is evenly applied. Thereafter, it is guided to the focusing guide 6. The yarn bundled into one bundled yarn (by these guides) is taken off at a predetermined take-up speed by the godet roller group 7, and then transferred to the final nip roller 8.
After being separated from the godet roller group, it is stored in the storage can 9.

(A) to (A) in FIG. 3 are examples of accompanying airflow guide plates used in the present invention. (A) uses a set of two plates, and when viewed from the direction B, the relationship between the yarn 2, the guide plate 4, and the oiling guide 5 is as shown in (A) in Figure 5. The oiling guide may be stepped as shown in FIG. 5(c), and the guide plate may be a flat or curved plate. Of course, it must be gas-impermeable to a degree that allows for rectification.

Figure 3 (b) uses a set of four plates, (c)
2) is an inverted square pedestal with a slit at the position of the oil ring; This guide plate has a slit-like shape at the oiling position and has a similar shape to the cut cross section of the entire yarn.

Figure 4 (a) is a cross-sectional view of Figure 3 (a) taken along a plane that includes A A' at the uppermost end of the guide plate and is perpendicular to the traveling thread; ) are (b) and (→
, A is a cross-sectional view taken along a plane perpendicular to the running yarn, including A A' at the top end of the guide plate, and (C) in FIG. 4 is A at the top end of the guide plate. FIG. 5(a), which is a cross-sectional view taken along a plane including A' and perpendicular to the traveling yarn, is a side view seen from the direction of B in FIG. 3(a). FIG. 5(b) shows a guide plate having a curved shape.

In addition, the yarn guide in the present invention includes an accompanying airflow guide plate installed at a predetermined position, an oiling device, a focusing guide,
The yarn can be guided through the corded roller group or the nip roller.

Next, the effects of the present invention will be specifically explained with reference to Examples. The quality of the test results was determined based on 1) spinning condition - occurrence of single yarn breakage during spinning, 2) adhesion efficiency of oil agent, etc.

The evaluation was performed based on the following criteria.

(1) Spinning condition ○ mark - the number of single yarn breakages is 5 or less times in 80 hours of spinning ■ mark - the above number of single yarn breakages is 6 to 20 △ mark - the above number of single thread breakages is 21 to 50 times × mark - above The number of single thread breaks is 51 or more times (2) Oil adhesion efficiency ○ mark - Actual adhesion rate 97 times or more compared to the theoretical applied amount 0 mark - Actual adhesion rate 97 to 94% Δ mark - Actual adhesion rate 94 to 80% × mark - Actual adhesion rate below 80 cm Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.63 measured at 30'C using a Mfl mixed solvent of phenol and tetrachloroethane was attached to a three-point support type with an outer diameter of 2 .3
xg perforation surface ￥ [jj Using a spinneret with 28.5- hollow holes and 700 holes, spinning temperature 295°C1
Single hole discharge rate is 4.0P/min and pulling weir speed is 3500.3
800. The ratio is changed to 4000 m/min and the spinning take-off υ is performed. At this time, the length of the slit in the rod-shaped oiling guide is 2
When using an accompanying airflow guide plate at 0cWL, see (
B) type, and the upper guide plate has a length of 28 cIr.
L, height gc + a, left and right guide plates length 71, height 8
cWL, and the guide plate at the bottom has a length of 26α and a height of 2.
It is equipped with 0 equipment, and there are no guide boards on either side. The cross-sectional area of the guide plate (S)/the cross-sectional area of the yarn (S') when cut along a plane perpendicular to the light beam at the top end of the guide plate was set to 3. The test was conducted with the oil ring position and cooling conditions fixed to the following conditions.

(1) Position of oiling; 220. below the spinneret.
232Gi (2) Cooling air blowing position; 300 below spinning metal (3) Cooling zone length; 80 cWL (4) Cooling air temperature; 24℃ (6) Cooling air speed; 1.5□/sec Test results Shown in Table 1. Although not shown in Fig. 2, the lubricant was applied by feeding a predetermined amount from a gear pump through piping to the supply port. This is an example using an airflow guide plate, and good results were obtained.

On the other hand, Tests 41 to 3 were examples in which no guide plate was used, and as the take-up speed increased, single yarn breakage increased and winding became difficult.

Example 2 Polyethylene terephthalate with an intrinsic viscosity of 0.645 measured at 30°C using an MR mixed solvent of phenol and tetrachloroethane was made into a T-shaped pore type with a pore area of 2.3 rnj and 595 pores. Using a spinneret, the spinning temperature was 295°C, the take-up speed was 4250 m7 minutes, and the single-hole discharge rate was 4.
．． A raw yarn having a single yarn denier of 8.5 denier was obtained by spinning at 0 f/'min. At this time, the slit length of the oiling guide was 15α, and guide plates with different lengths, heights, etc. were used to perform spinning and winding.

The test was conducted with the oiling position and cooling conditions fixed to the same conditions as those shown in Example 1. The test results are shown in Table 2.

In the following margin test A, conditions A10 to A412 were within the preferred range of the present invention and showed good spinnability.

On the other hand, in Test &7, the length of the accompanying airflow guide plate was
In addition, since the height of the guide plate of &8 was out of the preferred range, single yarn breakage or roll-up due to this occurred to some extent, and the yarn could not necessarily be wound up satisfactorily. In addition, since the height of the guide plate is outside the range (Tess) / 9), it collects too much accompanying airflow, causing the yarn to sway and causing uneven adhesion of oil. Under spinning conditions, using a guide plate with a slit-like shape in the oiling section, which is an inverted square bevel, the entire yarn is cut in a plane perpendicular to the height of the guide plate and the running yarn. Cross section:! (S')
and the cross-sectional area of the guide plate (S), (S/S')
The value of was changed from time to time and rolled up. The results are shown in Table 3.

Test) A15 to A16 of A were within the preferred range of the present invention and exhibited good spinnability. On the other hand, in test A13.18, the height of the guide plate is outside the preferred range of the present invention, and in test A14.17, the value of S/S' is outside the preferred range, so the single yarn Breaks, spots of oil adhesion, and scattering of oil were observed, and unsatisfactory winding of the yarn was not always possible.

[Brief explanation of the drawing]

FIGS. 1A and 1B are diagrams showing an example of the pore arrangement of the spinneret used in the present invention, and FIG. 2 is a schematic diagram showing an embodiment of the spinning take-off device used in the present invention. Fig. 3 is a diagram showing an example of the accompanying airflow guide plate used in the present invention, Fig. 4 is a cross-sectional view taken along a plane perpendicular to the running yarn, and Fig. 5 is a diagram showing an example of the accompanying airflow guide plate used in the present invention. It is a side view when seen from the B direction. In these figures, 1 is the spinneret, 2 is the yarn, 3 is the cooling zone, 4 is the accompanying air guide plate, 5 is the rod-shaped oiling guide, 6 is the focusing guide, 7 is the godet roller group, 8 is the nip roller, and 9 is the storage Each represents a can.

Claims (1)

[Claims] 1. A thermoplastic polymer is melt-extruded from the pores of a spinneret having 400 or more pores, cooling air is applied to the formed yarn, and the vicinity of the oil supply slit provided in the rod-shaped object is An oil agent is applied to the yarn by bringing the yarn into contact with the
In a melt spinning method in which the yarn is taken up at a speed of 00 m/min or more, at least the front and back sides of the yarn are tilted almost directly above the rod-like object so that the closer they get to the rod-like object, the closer they are to the yarn. A melt-spinning method characterized by surrounding the fibers with a plate-like material having 2. The method according to claim 1, wherein the pores are arranged on a plurality of parallel lines in the spinneret, and the cooling air is blown out from one direction perpendicular to the parallel lines. 3. The horizontal length (xcm) at the lowest end of the plate-like object, the height (Zcm) of the plate-like object in the direction parallel to the yarn, and the length of the oil supply slit provided in the rod-like object of the rod-like oiling device. difference(
ycm), number of spinneret holes (H), cross-sectional area of the entire yarn when cut in a plane perpendicular to the running direction of the yarn at the top end of the plate (S'cm^2) The cross-sectional area (Scm^2) of the cut surface of the plate-like object at the same location is calculated by the following formula (
The method according to claim 1 or 2, which satisfies conditions 1) to (4). y+2≦x≦y+10・・・・・・・・・・・・(1) 0.004H≦y≦0.04H・・・・・・・・・・・・
・(2) 2≦Z≦30 (3) 1.5≦S/S′≦10 (4
4. The method according to any one of claims 1 to 3, wherein the distance (lcm) from the spinneret to the oil supply slit of the rod-shaped oiling device satisfies the following formula. 12H/(√(H)+y)≦l≦24H/(√(H)+
y) (however, H and y have the same meaning as above)