JPS5936686B2 - Liquid bath stretching equipment for synthetic fiber tow - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid bath stretching apparatus for synthetic fiber tow, and its purpose is to improve the drawing operation of stable synthetic fibers with uniform strength and dyeability. An object of the present invention is to provide an improved liquid bath drawing apparatus for high speed production.

Conventionally, a method has been known in which synthetic fiber tow is stretched while running in a heating bath.

This method can uniformly heat the inside of the tow, so there are fewer dyeing defects (
(due to incompletely drawn yarn) has the advantage of being less.

However, when the tow drawing speed is increased to achieve high productivity, the bath liquid in the drawing bath is accompanied by the high-speed running tow and moves to the drawing roller side, causing the running tow on the supply roller side to run out of liquid. This causes the so-called liquid level tilting phenomenon in which the liquid level on the supply roller side becomes low and the liquid level on the drawing roller side rises, causing the bath liquid to foam and pulsate, making it impossible to achieve uniform heating of the tow, and furthermore, the liquid level on the drawing roller side becomes high. Unless the large amount of bath liquid that has been transferred is forcibly returned to the supply roller side by some means, the liquid shortage phenomenon will not be resolved, and if this continues, uneven stretching will result, and the stretching operation will have to be abandoned. This resulted in the inconvenience of not being able to obtain any benefits.

Therefore, in the past, a large amount of bath liquid that had been transferred to the drawing roller side was continuously forcedly circulated to the supply roller side using a liquid sending pump to maintain the liquid level in the drawing bath horizontally.

However, the amount of bath liquid that moves along with the running tow from the supply roller side to the drawing roller side increases exponentially as the drawing speed increases, so it is difficult to operate at a drawing speed of 300 m1m1n or higher. In this case, it is necessary to install a large-capacity liquid pump, which has the drawback that the running cost for operating the pump is extremely high.
Moreover, the foaming and pulsation of the bath liquid become intense, resulting in the disadvantage that uniform stretching cannot be achieved.

The present invention eliminates such conventional drawbacks and provides an improved liquid bath drawing apparatus that can produce stable synthetic fibers with uniform strength, elongation, and dyeability at high speed with good drawing operation. The gist of the system is to provide a rectifier in which a plurality of perforated rectifying plates are arranged above and below a tow travel path in the center of the housing, and the gist thereof is a casing in which both ends are substantially open in an elongated bathtub. This is a liquid bath stretching apparatus for synthetic fiber tow, characterized in that the apparatus is arranged with a space provided between the front and rear walls and the bottom and/or side walls of a stretching bath for natural circulation of bath liquid.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a partially cutaway side view of a liquid bath stretching apparatus showing an example of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG.
FIG. 4 is an enlarged longitudinal sectional view taken along line A, and FIG. 4 is an enlarged view of the circle C portion in FIG.

As shown in FIGS. 1 and 2, the tow T is introduced into the drawing bath 3 by a supply roller 1 outside the bath and a supply roller 2 (hereinafter referred to as an inlet roller) partially immersed in the bath. 4, the stretching roller 6 (hereinafter referred to as an outlet roller) partially immersed in a stretching bath rotating at a circumferential speed several times that of the supply roller and the stretching outside the bath. It is stretched by rollers 7 to several times its original length.

The flow straightening device 5 consists of a casing that is substantially open at both ends (that is, the tow inlet side and the tow exit side), and a plurality of porous rectifying plates 9, 9 are provided above and below the tow travel path 8 in the center of the casing. ...is arranged.

The flow straightening device 5 is thus arranged with a space for natural circulation of the bath liquid between the front wall 10, the rear wall 11 and the bottom 12 and/or side walls 13, 13' of the elongated bathtub.

That is, the flow of the bath liquid shown by the streamline arrow in FIG.
It collides with the rear wall 11 of the stretching bathtub, turns downward, and then flows toward the front wall 10 of the stretching bathtub, passing between the bottom plate 14 of the flow straightening device and the bottom surface 12 of the stretching bathtub, and is then entrained by the tow T. This is a natural circulation flow in the vertical direction, which flows into the rectifier 5 and flows out from the rear end of the rectifier 5 again. Among the bath liquid flowing out from the rear end of the rectifier 5, the bath liquid above the toe collides with the extended and downwardly curved rear end 16 of the upper plate 15 of the rectifier, and the entrained bath liquid separation plate 17 towards the side walls 13.13' of the drawing bath, and then the sides 13.13' of the drawing bath and the side plates 18 of the flow straightener,
The front wall of the bathtub extends through the space divided by 18'
0 direction, and is then accompanied by the tow T and flows into the rectifier 5.
This is a horizontal natural circulation flow that flows into the tank and flows out again from the rear end of the rectifying device toward the side wall 13, 13' of the drawing bath.

As described above, in the present invention, the rectifying device 5 is arranged on the front and rear walls of the elongated bathtub so that the bath liquid entrained in the tow forms a natural circulation flow in the vertical direction and/or a natural circulation flow in the horizontal direction. , which is placed in a stretched bathtub with consideration given to the distance between the bottom surface and the side walls.

In particular, in the present invention, it is preferable that the vertical natural circulation flow be the main flow.

In this case, the natural circulation of the bath liquid is extremely smooth, and the means 19 (heating medium jacket, heating coil, etc.) for heating the bath liquid is provided at the bottom of the drawing bath to forcefully stir the bath liquid. There is an advantage that uniform heating of the bath liquid can be achieved without heating.

Next, the rectifier according to the present invention will be explained in more detail.

Figures 1 and 2 (The rectifying device 5 shown is a top plate 15, a bottom plate 14
, a casing with both ends open formed by side plates 18 and 18', and inside the casing are multiple rectifying plates 9, 9, etc. as shown enlarged in FIGS. 3 and 4. A plurality of perforated plates 9 are arranged above and below the tow running path 8 in the center,
For 9..., it is appropriate to have a porosity of 20 to 80%,
Any material such as wood, metal, or plastic can be used.

The shape of the hole 20 may also be arbitrary, such as circular, oval, or rectangular.

Preferably, this perforated plate is supported by the side plates 18.degree. and 18' of the rectifying device so as to be adjustable in angle.

That is, as shown in FIG. 4, it is preferable to install the tow so that the inclination angle θ with respect to the running direction can be arbitrarily changed within the range of 20 to 90 degrees.

Further, it is preferable that the tip of the perforated plate be placed as close as possible to the tow so that the entrained flow of the tow has many surfaces in contact with the perforated plate.

The effect of the perforated plate is to reduce the flow rate of the bath liquid flowing from the inlet roller side to the outlet roller side along with the traveling tow, effectively preventing the liquid level tilting phenomenon of the drawing bath, and thereby uniformly drawing the tow. It's about achieving.

That is, the bath liquid accompanying the tow collides one after another with a large number of perforated plates arranged in parallel above and below the running tow, and as shown in Figure 4, the direction of flow is changed between adjacent perforated plates. The bath liquid is changed to form a vortex, and the bath liquid that has passed through the holes 20, 20... of the perforated plate and the bath liquid that has passed through the tow travel path between the tips of the upper and lower perforated plates is transferred from the rear end of the rectifier to the outlet roller side. flows to.

By using such a rectifying device, the entrained flow of the running tow is significantly reduced compared to the case where such a rectifying device is not used.

In order to facilitate the vertical natural circulation of the bath liquid flowing out from the rear end of the straightener towards the inlet roller, the rear end of the bottom plate of the straightener is extended substantially below the outlet roller as shown in Figure 1. , it is preferable that the rear end portion 21 is curved upward.

In addition, in order to prevent the bath liquid flowing out from the rear end of the straightening device from colliding directly with the outlet roller and causing turbulence and foaming of the bath liquid at this part, and to facilitate natural circulation in the horizontal direction, the first As shown in Figures 1 and 2, the rear end of the upper plate of the rectifier is substantially extended to the vicinity of the outlet roller,
Preferably, the rear end 16 is curved downward to the extent that it does not contact the tow.

At that time, a vertical entrainment bath liquid separating plate 17 is provided at the center of the rear end portion 16, so that the bath liquid flowing out from the upper part of the toe at the rear end of the rectifying device is diverted from the side wall 13, 13' of the drawing bath.
It is better to point in the direction.

The rectifying device 5 is constructed so that it can be divided into upper and lower sections substantially on the same plane as the tow traveling road surface by a hinge 22 or the like, as shown in FIG. It is better.

Before starting the stretching operation, in order to make the temperature of the bath solution uniform and the concentration of the oil agent added to the bath solution,
Pipe line 2 for forced circulation of bath liquid between the front and rear parts of the extended bathtub
3, and the liquid feeding pump 23 is preferably operated to forcibly mix the bath liquid 4 in advance.

After the stretching starts, the bath liquid is continuously mixed by natural circulation, so the pump 24 does not need to be operated.

Heat fixing process via outlet roller (not shown)
Since a large amount of drawing bath liquid adheres to the drawn tow being transferred to the outlet roller, the drawing tow is held on the peripheral surface of the outlet roller and the liquid draining roller 25 is pressed to draw the bath liquid adhering to the drawn tow. It is useful to provide a draining roller because dropping the film into the bathtub saves the drawing bath liquid and at the same time saves energy in the heat setting process.

Since the present invention is configured as described above, forced circulation of bath liquid as in conventional liquid bath stretching is not required, and therefore, the running cost of stretching is low, and the present invention is an energy-saving type liquid bath stretching apparatus. Highly uniform, 200
This is a useful invention suitable for high-speed tow stretching of m 2 /min or higher.

Next, examples will be shown.

Example 1 A 2,000,000 d tow of polyethylene terephthalate fiber for staple production produced by a conventional method was drawn using the same liquid bath drawing apparatus of the present invention as shown in FIGS. 1 to 4, with the drawing speed varied in several stages. The content of incompletely drawn yarn in the obtained stretched tow was examined.

A punching board with a porosity of 50% was used as the perforated plate of the rectifier, and the temperature in the bathroom was 73°C.

For comparison, results are shown as a conventional method in which stretching was carried out under the same conditions as in this example, except that no rectifier was used and the bath liquid was forcibly circulated by a pump.

As is clear from the above table, in the case of the present invention, the content of incompletely drawn yarn in the drawn tow is significantly improved compared to the conventional method.
It can be seen that it provides extremely excellent uniform stretchability.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a liquid bath stretching apparatus showing an example of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG.
FIG. 4 is an enlarged longitudinal sectional view taken along line A, and FIG. 4 is an enlarged view of the circle C portion in FIG. 2... Supply roller partially immersed in the stretching bath, 3... Stretching bath, 4... Bath liquid, 5...
. . . Straightening device, 6 . . . Stretching roller partially immersed in the stretching bath, 8 . . . Tow running path, 9
... Porous rectifying plate, 10 ... Front wall of the extension bathtub, 11 ... Rear wall of the extension bathtub, 12 ...
...Bottom surface of the stretched bathtub, 13, 13'...Side wall of the stretched bathtub, 14...Bottom plate of the rectifier, 15...
... Upper plate of the rectifier, 16... Rear end of the upper plate of the rectifier, 17... Entrained bath liquid separation plate, 18,
18'...Side plate of rectifier, 19...
Means for heating the bath liquid, 20... Holes of the perforated plate, 21... Rear end of the bottom plate of the rectifier, 23...
...Pipe line for forced circulation of bath liquid, 25...
・Liquid draining roller, T...Tow.

Claims (1)

[Scope of Claims] 1. A rectifier comprising a casing substantially open at both ends in an elongated bathtub, and a plurality of porous rectifier plates arranged above and below a tow travel path in the center of the casing. 1. A liquid bath stretching apparatus for synthetic fiber tow, characterized in that the apparatus is arranged with a space provided between the front and rear walls and the bottom and/or side walls of a stretching bath for natural circulation of bath liquid. 2. The liquid bath stretching apparatus for synthetic fiber tow according to claim 1, wherein the straightening device is disposed between the supply roller and the stretching roller, which are partially immersed in the stretching bath. 3. A liquid bath stretching apparatus for synthetic fiber tow according to claim 1 or 2, wherein the front and rear parts of the stretching bath are connected by a pipe line for forced circulation of bath liquid. 4. A liquid bath stretching apparatus for synthetic fiber tow according to any one of claims 1 to 3, wherein means for heating the bath liquid is provided at the bottom of the stretching bath. 5. A liquid bath stretching device for synthetic fiber tow according to claim 1 or 2, wherein the straightening device is configured to be able to be divided into upper and lower sections substantially on the same plane as the tow running road surface. 6. The liquid bath stretching apparatus for synthetic fiber tow according to claim 1, wherein the perforated rectifying plate of the rectifier is arranged so as to be adjustable in angle with respect to the running direction of the tow. T The perforated rectifier plate of the rectifier is 20
A liquid bath stretching apparatus for synthetic fiber tow according to claim 1 or 6, wherein the apparatus is arranged at an angle of ~90 degrees. 8. The liquid bath stretching apparatus for synthetic fiber tow according to claim 1, 6 or 7, wherein the porous rectifying plate of the rectifying device is a punching board with a porosity of 20 to 80%. 9. The liquid bath stretching device for synthetic fiber tow according to claim 2, wherein the rear end of the bottom plate of the straightening device extends substantially below the stretching roller immersed in the stretching bath. 10. The synthetic fiber tow according to claim 9, wherein the rear end of the bottom plate of the straightening device extends substantially below the stretching roller immersed in the stretching bath, and the rear end portion is curved upward. Liquid bath stretching equipment. 11. The synthetic fiber tow according to claim 2, wherein the rear end of the upper plate of the straightening device substantially extends to the vicinity of the stretching roller immersed in the stretching bath, and the rear end portion is curved downward. liquid bath stretching equipment.