JP2734459B2 - Yarn heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yarn heat treatment apparatus and, more particularly, to a heating fluid injection slit nozzle having a wider width than conventional ones, and having a uniform velocity distribution of the heating fluid. The present invention relates to an improved yarn heat treatment apparatus.

[0002]

2. Description of the Related Art In a stretching step and a heat treatment step of a synthetic fiber, the yarn is stretched at a high temperature, or a crystallization treatment or a solid phase polymerization is carried out. In particular, in the stretching process, steam heating (FS Smith. J. Text.
t. , 1980. pp. 50-59). In an actual heat treatment apparatus for injecting a heating fluid, it is important to have a heating efficiency and to prevent stretching disturbance due to yarn sway. Nowadays, from the viewpoint of productivity, as the number of windings of two or more ends has become mainstream, the width of the heat treatment apparatus has to be widened and the fluid flow law in the direction has to be uniform.

A specific heat treatment apparatus is disclosed in
JP-A-39190 and JP-A-60-88149 have been proposed, but none of these types has sufficient characteristics. In other words,
In the heat treatment apparatus having the shape of JP 39190, since the cross-sectional area of the heat retaining portion is large, the heating fluid flow rate in this portion is low, so that not only sufficient heating efficiency cannot be obtained but also the ejection speed of the heating fluid ejection portion in the width direction. Since the uniformity is not guaranteed, the yarn has a drawback that the yarn is likely to be damaged by strong turbulence in the flow. JP 60
The heat treatment apparatus disclosed in JP-A-88149 has a drawback that the draw ratio becomes low because the temperature of the yarn cannot be sufficiently increased under the condition of a high yarn speed because the total length is short.

[0004]

SUMMARY OF THE INVENTION The present invention has been developed to improve the drawbacks of the conventional heat treatment apparatus using a heating fluid, particularly to improve the heating fluid to make the velocity distribution of the heating fluid uniform and wide.
In addition to the high efficiency and little stretching disturbance due to yarn sway,
An object of the present invention is to provide a heat treatment that can be used for speeding up production and multi-end production.

[0005]

If the heating fluid coming out of the slit-shaped outlet provided in the width direction substantially perpendicular to the longitudinal direction of the object to be heated has a speed distribution in the width direction, the flow due to the speed difference will occur. Since the object to be heated is shaken violently and shakes violently, the object to be heated is damaged by contacting adjacent objects to be heated and the inner wall of the heat treatment apparatus. Further, in the case of drawing a yarn, the drawing tension fluctuates due to the swinging of the yarn, which may cause breakage of the yarn. Further, if the heating fluid velocity differs in the width direction of the heat treatment apparatus, the efficiency of heat transfer to the object to be heated changes. It is known that the relationship between the heating fluid flow velocity and the heat transfer coefficient is proportional to the heating fluid velocity to the 0.8th power from an analogy with the empirical formula for the plate boundary layer heat transfer (edited by the Japan Opportunity Society, electrothermal optics, p18). ing. As a result of intensive investigations to eliminate the widthwise flow velocity difference of the slit jet outlet, the present invention, which has been reached, is a heat treatment apparatus that introduces a yarn to be processed into a pipe and injects a heating fluid into the pipe to a traveling yarn. , A heating fluid supply unit 2, a plurality of heating fluid throttle holes 3, a chamber 9, and a slit nozzle 4 as main parts, and a supply pipe sectional area A of the heating fluid supply unit and a total area na of the heating fluid throttle holes. (Na / A) is 0.35 or less, and the pitch between holes of the heating fluid throttle hole is L / 5 (mm) or less. (However, L indicates the length (mm) of the chamber from the outlet of the heated fluid throttle hole to the outlet of the slit nozzle 4)

It is preferable to use heat exchange with a heating fluid having no frictional contact with a solid when heat-treating an object to be heated such as a yarn by a fluid heating heat treatment. The method of spraying on the body is excellent in that the heating efficiency can be controlled. The heating fluid of the present invention may be heated air, heated inert gas such as nitrogen or argon, superheated steam, or any gas containing an organic solvent or an acid or alkali in a liquid phase. The heating fluid heat treatment apparatus of the present invention is preferably one in which the cross-sectional area of the tubular portion where the yarn and the heating fluid come into contact with each other does not change much with respect to the ejection area of the slit nozzle. It is preferable that the area change when the yarn and the heating fluid flow from the slit-shaped ejection nozzle into the tubular portion in contact with the yarn is within ± 50%. An increase in the area of plus 50% or more is not preferable because the heating efficiency becomes insufficient because the flow rate of the heating fluid is too low. If there is a large area decrease of less than -50%, the static pressure at the slit nozzle ejection part will be high, so make the pressure change from the fluid supply pipe to obtain a uniform flow velocity distribution in the slit nozzle width direction. Is not preferred because it is not possible. The flow velocity of the heating fluid ejected from the slit nozzle is changed depending on the traveling speed and thickness of the object to be heated, the temperature and type of the heating fluid, and the like. The present invention is not limited by the type of the heating fluid, the geometric conditions of the tubular portion such as the change in the flow path area at the slit nozzle outlet, the steam flow rate, the type of the object to be heated, and the purpose of the heating step.

A feature of the present invention resides in that the flow velocity of the heating fluid ejected from the slit nozzle has a uniform velocity distribution in the slit width direction. If a supply pipe is simply connected to a slit nozzle, particularly a wide slit nozzle, a uniform velocity distribution cannot be obtained in the slit width direction. Therefore, it is common to provide a pressure chamber and supply the heating fluid to the slit nozzle from the pressure chamber. However, in this method, the pressure chamber for obtaining satisfactory uniformity of the flow velocity becomes enormous, and the heat treatment apparatus becomes large. Is not preferred. In view of this, a space (chamber) in which a throttle hole array and a fluid from the throttle hole spreads is further provided between the pressure chamber and the slit nozzle.

In the heat treatment apparatus of the present invention, the flow of the heating fluid from the supply section to the slit nozzle through the throttle hole array is schematically shown in FIG.

In the present invention, it is preferable that the blowing width of the heating fluid is 20 mm or more. If the blowing width of the heating fluid is less than 20 mm, it cannot be used as a heat treatment apparatus suitable for multi-end production as the object of the present invention. Among such heat treatment apparatuses having a wide width, a heat treatment apparatus having a slit-shaped ejection port with a uniform flow velocity in the width direction is preferred. In addition, a row of throttle holes is provided in the width direction of the heating fluid supply portion so as to distribute the flow rate so that the flow velocity in the width direction of the slit becomes uniform. Specifically, it is necessary to make the flow passage cross-sectional area (A) sufficiently small. Specifically, the flow passage area is the product (na) of the area (a) of one throttle hole and the number (n) of the throttle holes. The ratio to (A) needs to be 0.35 or less. If this ratio is larger than 0.35, the fluid cannot be uniformly distributed because there is not enough resistance to cancel the dynamic pressure of the fluid in the supply section. More preferably, the product (na) of the area (a) of one aperture and the number (n) of apertures
Is preferably 0.30 or less. The limit value of the aperture ratio (na / A) may be any value at which a desired flow rate of the heated fluid can be discharged, and especially when low-speed ejection is performed, the area of one throttle hole is reduced. It can be set to about 01.

[0010] In order to obtain a uniform velocity distribution in the width direction of the slit nozzle, the pitch between the holes in the throttle hole row must satisfy a specific condition. That is, as shown in FIG. 1, the heating fluid flowing out of the throttle hole is ejected and flows out into the chamber,
Spreading in the direction perpendicular to the jetting direction is gentle, and a certain length in the jetting direction is necessary to make a uniform velocity distribution by interfering with the jet flowing from the adjacent throttle hole. This length tends to be shorter as the pitch between the apertures is smaller. Conversely, when the pitch between the apertures is larger, the distance (L) from the outlet of the aperture to the outlet of the slit-shaped ejection nozzle is large.
Must be increased, and the size of the apparatus increases. In the heat treatment apparatus of the present invention, the pitch between drawn holes (p) needs to be L / 5 or less. If p exceeds L / 5, the uniformity of the velocity distribution of the heating fluid discharged from the slit-shaped ejection port deteriorates. The lower limit of the aperture row pitch (p) may be any size as long as the apertures do not overlap and there is no problem in processing.

The heat treatment apparatus of the present invention can be used for a high-speed stretching step by increasing the overall length. As shown in the example of FIG. 2, the heating fluid is caused to flow in both directions of cocurrent (same direction) and countercurrent (reverse direction) with respect to the yarn traveling direction, or simultaneously with cocurrent (same direction) and countercurrent (reverse direction). By spouting under satisfying conditions, it is possible to secure a sufficient flow velocity in spite of the heat treatment apparatus having a long overall length. Further, it is possible to change the type, temperature, flow rate, etc. of the heating fluid on both sides of the ejection port of the heat treatment apparatus. Changing the fluid temperature in the countercurrent portion and the flat flow portion in a heat treatment apparatus having a total length of 200 mm or more is extremely effective for stabilizing the extension. When the heating fluid flows in two directions toward both ends of the heat treatment apparatus, the heating fluid ejection position should be located at the center of the heat treatment apparatus except for the entrance side 20% of the yarn and the exit side 20% of the yarn over the entire length of the heat treatment apparatus. Is preferred. That is, in terms of the ratio to the total length of the heat treatment apparatus, it is preferable to provide a slit-shaped outlet at a position of 20% or more and 80% or less with the yarn entrance as the origin. If the ejection port is provided extremely beyond the end, not only the energy loss of the heating fluid is large, but also the heating efficiency is reduced, so that the length of the heater cannot be fully utilized.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples. The performance of the heat treatment apparatus was evaluated by the following measurement method.

1. Fluid flow rate was measured using a pitot tube having an outer diameter of 1.1 mm. The dynamic pressure tube and the static pressure tube were inserted separately.

2. Thermal stress peak temperature: Tp Thermal stress strain measuring device TMA / SS120 manufactured by Seiko Electronics Co., Ltd.
C was measured. The sample was separated into fibers of 150 denier, and the shrinkage stress was measured at a yarn length of 20 mm and a heating rate of 20 ° C./min, and the temperature at which the shrinkage stress was maximum was determined as a thermal stress peak temperature (Tp).

Embodiment 1 In Embodiment 1, the conditions of a throttle for obtaining a uniform heated fluid jet flow velocity in the width direction will be described.

A heating apparatus having a slit nozzle as shown in Table 1 was prepared using superheated steam (350 ° C.) as a heating fluid, and the widthwise distribution of the flow velocity at the slit nozzle outlet was measured. 1. The measurement position is on a 1 mm line in the ejection direction from the ejection edge on the center plane in the thickness direction of the slit nozzle.
The pitch was 5 mm. When the slit width was 50 mm and the slit thickness was 3 mm, 19 points were measured, and the average value and the difference (range) between the maximum value and the minimum value were determined. In the example, nine types of slit nozzles were manufactured, and the supply pressure of the superheated steam was finely adjusted so that the average flow rate was adjusted to a predetermined value.

[0017]

[Table 1]

As shown in FIG. 4, if the aperture ratio (na / A) is 0.35 or less, a uniform jet velocity distribution can be obtained. The chamber length (L) is (L / p) is 5
If the above conditions are not satisfied, the uniformity of the jet flow velocity becomes extremely poor. The aperture ratio (na / A) is 0.35
When (L / p) is 5 or more, good slit-shaped ejection with a small range of the flow velocity distribution in the width direction becomes possible.

Embodiment 2 In Embodiment 2, the condition of the slit nozzle position with respect to the entire length of the heater will be described.

Polyethylene terephthalate having an intrinsic viscosity of 1.1 is discharged from four 240-hole nozzles, cooled and solidified by a quench at 50 ° C., and taken up by a roll at a spinning speed of 4200 m / min without overlapping four yarns. Followed by 3%
Was drawn directly under the heater conditions and draw ratios shown in Table 2 between a feed roll and a draw roll which gave a pre-stretch, and while giving 1% relaxation, four 750-denier drawn yarns were simultaneously wound. FIG. 3 schematically shows a heat treatment apparatus assembled between a feed roll and a draw roll.

[0021]

[Table 2]

In Table 2, the ejection position (X) is shown as a percentage of the total length with the entrance as the origin in the longitudinal direction of the heater. 1
With a 000 mm heater, stretching at a high magnification was possible at high speed, and the drawn yarn strength was increased. The thermal stress peak temperature (Tp) of the drawn yarn is estimated as the drawing temperature in the heater.
Thermal stress peak temperature (Tp) and maximum draw ratio (DRma)
x) is high and reflects that the heating of the yarn is sufficient when the ejection position (X) of the present invention is 20% to 80%. When the jetting position was at the end, the stretching ratio could not be increased.

[0023]

As apparent from the above description, the yarn heat treatment apparatus of the present invention has a wide width, a uniform distribution of the flow velocity of the heating fluid in the width direction, multi-end production is possible, and Efficiency is high, drawing disturbance due to yarn sway is small, and independent outlets can be provided in the countercurrent and parallel flow areas, so that the thermal efficiency of long heat treatment equipment can be sufficiently increased to support high-speed processes And a heat treatment apparatus capable of performing the heat treatment.

[Brief description of the drawings]

FIG. 1 is a view showing a main part of a yarn heat treatment apparatus of the present invention, and is a view schematically showing a flow of a heating fluid from a supply section through a throttle hole to reach a slit nozzle.

FIG. 2 is a view showing a main part of the yarn heat treatment apparatus of the present invention, and is a view showing an embodiment of an arrangement of slit nozzles.

FIG. 3 is a view showing an embodiment of the heat treatment apparatus of the present invention, and is a view showing an embodiment installed between a feed roll and a draw roll.

FIG. 4 is a diagram showing the relationship between the ratio (na / A) of the cross-sectional area A of the supply pipe to the total area of the heating fluid throttle holes and the rate of change of the flow velocity of the jet from the slit nozzle.

[Explanation of symbols]

 A: Cross-sectional area of supply pipe a: Cross-sectional area of throttle hole L: Chamber length W: Slit width 1: Heat treatment device main body 2: Heated fluid supply part 3: Heated fluid throttle hole 4: Slit nozzle 5: Yarn to be treated 6: Feed roller 7: Draw roller 8: Slit nozzle mounting part 9: Chamber

Claims (2)

(57) [Claims] 1. A heat treatment apparatus for introducing a yarn to be treated into a tube and injecting a heating fluid into a running yarn in the tube, comprising a heating fluid supply unit 2, a plurality of heating fluid throttle holes 3, a chamber 9, and a slit. The ratio (na / A) of the supply pipe cross-sectional area A of the heating fluid supply unit to the total area na of the heating fluid throttle holes is 0.35 or less, and the nozzle 4 is a main part. A yarn heat treatment apparatus, wherein a pitch between holes is L / 5 (mm) or less. (However, L indicates the length of the chamber from the outlet of the heated fluid throttle hole to the outlet of the slit nozzle 4 (mm).) 2. A plurality of slit nozzles are provided,
The yarn heat treatment apparatus according to claim 1, wherein the injection direction of the heating fluid is arranged in a traveling direction and / or a countercurrent direction of the yarn to be treated.