JPS5855255B2 - High-speed heat treatment method for latent crimp fibers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of 1. (a) It is possible to continuously and stably develop crimp in the crimpable yarn at high speed, and then stably cool the crimp-treated yarn to fix the crimp that has completely developed. This invention relates to a relaxation heat treatment method that can be used.

Generally 1. In order to develop the latent crimp in a latent crimp yarn in a good condition and to fix the crimp, the latent crimp yarn must be maintained in an extremely low tension state where it can freely contract. It is necessary to carry out a heat treatment and, even after latent crimp has appeared, to perform a cooling treatment while maintaining this extremely low tension state.

For example, as a means to continuously carry out this relaxation heat treatment, Japanese Patent Publication No. 41-6291 discloses that heated air is used to develop the crimp, and after the crimp is developed, the yarn is removed with a baffle plate to remove some of the high-temperature exhaust air. A cooling method using an air aspirator is described in Japanese Patent Publication No. 43-534, and a method is described in Japanese Patent Publication No. 45-54772 that describes a method in which airflow from below to upward is used to create crimps with virtually no tension in the yarn. Method of Relaxation Heat Treatment by Forcibly Contacting the Inner Wall of a Heating Tube, Japanese Patent Publication No. 46-2
No. 2882 describes a method of using double pipes in the relaxation heat treatment zone to recover heated air from below and return it to the yarn inlet to prevent the fiber yarns from being disturbed by turbulent airflow, Japanese Patent Publication No. 46-2768.
In order to subject the fiber threads to relaxation heat treatment in a heated gas flow, the fiber threads and the heated gas flow are combined and then introduced into the heating cylinder, and at the same time a secondary gas flow is introduced into the heating cylinder from near the inlet. There are methods.

In all of these methods, the yarn discharged from the heating zone is regulated at high speed using a nip roller or the like, and then cooled while being maintained in a relaxed state under low tension.

However, in recent years, there has been a strong demand for increased productivity, and there has been a need to increase the processing speed.

When processing at high speed, the tension caused by winding with the pick-up roll does not propagate to the relaxation heat treatment zone in the heater, and the relaxation heat treatment is performed under sufficiently low tension, and the yarn discharged from the crimping and heating zone is With conventional techniques, it is difficult to apply cooling treatment while maintaining the sagging, relaxed state.

In particular, 1. It is extremely difficult to control the speed after heat treatment using a three-way roller, etc., and it is extremely difficult to wind the yarn stably while cooling the crimped yarn and keeping the crimp completely unstretched. .

An object of the present invention is to provide a relaxation heat treatment method that makes it possible to stably obtain a good crimp-producing yarn by subjecting a latent crimp yarn to a relaxation heat treatment at high speed and then continuously performing a relaxation cooling treatment. It's about doing.

A typical conventional example is Japanese Patent Application Laid-open No. 49-10031.
The method listed in FIG. 1 as shown in FIG. 6 is common.

In other words, when the latent crimpable yarn is subjected to relaxation heat treatment in the heating zone 3, the speed is completely regulated by the rollers 1 and 4 before and after the heating zone, and crimp occurs while giving an appropriate overfeed. After being cooled while maintaining a predetermined relaxed state in between, the material is wound onto a bobbin 8.

At this time, the speed regulation method used was to use a drive roll at 1°4.6 and nip rollers at 2, 5, and 7 to regulate the yarn speed. If the speed can be completely controlled by the rollers, the yarn discharged from the heating zone can be gripped by the nip rollers and the traveling speed can be regulated, and then the yarn can be maintained at a low tension for a certain distance and subjected to a relaxation cooling process. However, in practice, the use of nip rollers at high speeds is undesirable due to many problems in terms of durability and danger.

In addition, it is difficult to completely nip the yarn at high speed because of the large vibration phenomenon of the nip roller, and winding tension tends to propagate to the heating zone.

Moreover, when feeding the potentially crimpable yarn to the crimp-inducing heating zone at a speed of 1,000 m/min or more, especially when attempting to feed the yarn at a speed exceeding 2,000 m/min or even 3,000 m/min, the yarn A yarn suction device (ejector) is required to guide the yarn to the relaxation heat treatment zone, but as the yarn feeding speed increases, the air flow rate must naturally be increased.

When the amount of air supplied to the heat treatment zone increases, 1. At the same time, the amount of heated air that accompanies the developed yarn discharged from the heating zone also increases, making it more difficult to maintain the yarn path stably with less disturbance in the relaxed state.

This also makes it more difficult to regulate the yarn speed using a nip roller or the like.

If you use a three-way roller or similar device to guide the yarn to a guide and relax and cool the yarn with outside air without regulating the speed, the yarn will run unstable and become entangled in a way that makes it impossible to unwind the yarn. This creates a pill-like tangle that gets wound up on the bobbin, which can easily cause problems such as thread breakage during post-processing.

If one attempts to sufficiently cool the material after heat treatment in a relaxed state, the problems just described will arise.

Therefore, if the winding speed is increased to slightly suppress the relaxed state of the yarn discharged from the heating zone, the tension may be removed before the yarn developed in the heating zone is cooled to a sufficiently relaxed state. This results in an undesirable result in that the crimp that has been developed is stretched out by the winding tension.

Furthermore, the higher the processing speed, the more difficult it is to regulate the speed of the yarn discharged from the heating zone, and as a result, the winding tension in the pick-up lawn also propagates to the heating zone.
It becomes difficult to carry out the development process in a completely relaxed state, resulting in development yarns that are poorly crimped.

Therefore, it is extremely difficult to obtain a yarn that has very good stretchability and crimpability, and has properties comparable to conventional processed yarns such as false-twisting.

The present inventor has made earnest efforts to obtain a method for high-speed heat treatment of latent crimpable fibers that is free from the above-mentioned drawbacks and problems, and as a result, has arrived at the present invention.

That is, in the present invention, latent crimpable fibers running at high speed are crimped in a heating zone, discharged from the crimped heating zone, and more preferably, the discharged fibers are passed along a yarn guide device having a gap. By guiding the fibers, the fibers are caused to run in a predetermined direction while separating a part of the high-temperature airflow that accompanies the fibers, and then a low-temperature airflow in the same direction as the fiber running direction is applied to the fibers to sufficiently cool the fibers. This is a method for winding up crimped yarn at high speed.

The amount of latent crimpable fibers is 1000 mlmln or more, that is, 20
In order to introduce the yarn into the heating zone at an ultra-high speed exceeding 00 mlmln or even 3000 mlmln, it is necessary to provide an ejector at the top of the heating device to take it off from the supply roll.

The yarn introduced at an ultra-high speed by the ejector can be heated using any heating device of any structure, such as a cylindrical heating device or
9-100316, which has a collision plate inside, is heated to develop crimp.

The yarn discharged from the heating zone is accompanied by a large amount of heated air ejected from the ejector.

In the present invention, a portion of the high-temperature airflow that accompanies the crimped fibers in the heating zone is separated.

Such means are extremely effective for effectively performing the fiber cooling treatment described below and for sufficiently fixing the crimp.

At this time, the high-temperature airflow that accompanies the fibers also serves as a medium for the yarn to run at high speed, so if the airflow is completely separated, the yarn will not run smoothly, so maintain an appropriate flow rate. There is a need.

The degree of separation of this high-temperature airflow varies depending on the running speed of the yarn, the cooling treatment conditions described below, and the structure of the yarn guiding device, so the above conditions must be taken into consideration when setting the degree of separation. Separation of the hot air stream can be achieved by running the fibers without stagnation, by lightly contacting them with a guide, or by applying a light stream of air, but this does not disturb the fibers exiting the heating zone, especially under high speed processing. This is preferable, and in order to achieve this purpose, it is effective to guide and run the fibers along a yarn guiding device having a gap.

Examples of this device include a pipe with holes, a pipe-shaped cylinder made of wire mesh, a wire mesh or perforated plate integrally joined to the tip of the pipe, and a wire mesh or a plate with holes bent appropriately. Or, one arranged at an angle with respect to the fiber passage can be used.

This yarn guide device can be set in the same direction as the running direction of the yarn discharged from the heating zone, or can be bent or tilted in the usual direction, but the latter is recommended when using a wire mesh, perforated plate, etc. is valid.

The degree of separation of the high-temperature airflow in the thread guide device having these voids can be adjusted relatively easily by changing the void ratio.

The smaller the size of the void, the more preferable it is, and the appropriate porosity is 20 to 40%.

When using a wire mesh, one with a mesh size of 50 to 400 is preferable, and one with a mesh size of around 200 is most suitable from the viewpoint of ease of thread passage.

In either device, it is necessary to have a sufficiently smooth surface so as not to damage the surface of the fibers being discharged.

Since the high-temperature airflow is separated, the fibers that have passed through the yarn guiding device or the like are then cooled by being exposed to a low-temperature airflow in the same direction as the running direction of the fibers.

At this time, the fibers are cooled while maintaining a relaxed state, so 1.
The crimps do not return and are well fixed.

In the present invention, the direction of the low-temperature airflow for cooling is made the same as the running direction of the fibers in order to cool the fibers with the low-temperature airflow and at the same time provide a driving force.
By such a means, the crimped fibers can be run at high speed without applying excessive external force to the fibers until they are sufficiently cooled and solidified.

Therefore, a major feature of the present invention is that no nip rollers are required at all from the entrance of the heating zone until the crimped fibers are sufficiently cooled and solidified.

The easiest way to apply a low-temperature airflow to the fibers is to blow the low-temperature airflow into the tube in which the yarn runs. Same direction.

If the airflow is applied at an angle greater than that, the fibers may hit the tube wall or disturb the yarn path, which is disadvantageous in applying driving force.

Note that if the speed of the low-temperature airflow for cooling is extremely low, it will not be possible to give the fibers a sufficient relaxed state in the heating zone, and if it is significantly low, the purpose of high-speed processing cannot be achieved. In addition, the fibers tend to accumulate after the heating zone, causing the fibers to become stiff and causing the same defects as in conventional yarns. Therefore, the speed of the air flow blown by the ejector and the speed of the cooling air flow must be adjusted to balance each other. It is preferable.

Preferably, the yarn running through the U-shaped yarn guide device from below to above, ie in the recoil direction, is blown with a cold air stream from below to above.

According to this aspect, since the yarn running upward is in a relaxed state, the crimp is particularly well fixed by cooling.

When using a pipe for cooling, it is necessary to change the flow rate of low-temperature air sent into the pipe, the pipe diameter, and the pipe length depending on the degree of cooling of the hot air entrained in the yarn at that time.

When the amount of hot air entering the cooling pipe is relatively large, the flow rate of low-temperature air can be increased proportionally, and the cooling effect can be increased by increasing the diameter of the cooling pipe.

However, 1. If the tube diameter is made too thick, the yarn may become disordered, so the tube diameter should be 10 mm to 70 mm.
A diameter of about 30 to 40 is good, and in particular, if a diameter of about 30 to 40 is used, the yarn is less disturbed, and the cooling effect is sufficiently satisfied, so that the yarn can be wound stably.

The flow rate of low-temperature air does not make much of a difference to the yarn even when the flow rate is changed from the minimum flow rate required to transport the yarn through the cooling tube to a considerably large flow rate, and the relationship with the cooling temperature and the running stability of the yarn are important. An appropriate flow rate can be set from the viewpoint of performance.

The fibers, which have been cooled by the low-temperature air flow until the crimp is sufficiently fixed, can be taken up by a normal nip roller and wound onto a bobbin or the like.

The crimped fibers will not return to their crimped state even if they are subsequently subjected to tension or external force using a nip roller.

The latent crimped fibers used in the present invention include asymmetric cooling fibers made of thermoplastic polymers such as polyester and polyamide polyolefin, modified cross-section fibers, and core-sheath or side-by-side composite spun fibers.

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

As mentioned above, FIG. 1 is a schematic diagram showing an example of the prior art, and since the fibers leaving the heating zone 3 immediately pass through the nip roller 5, they are not suitable for processing high-speed running yarns as in the present invention. Can not.

FIG. 2 is an example of a typical apparatus for carrying out the present invention.

Supply roller 1 capable of feeding latent crimpable fibers 9 at high speed
In order to keep the tension between the supply roller and the ejector constant, the air pressure to the ejector is set to maintain a suction force that matches the supply speed, and the yarn is guided to the heating zone. send to.

The yarn subjected to the high-speed relaxation heat treatment in the crimp heating device 13 is discharged with hot air, and then sent to the yarn guide device 14 having a gap.

This yarn guide device 14 has a small hole in the right half of a U-shaped pipe, and as the yarn passes through the pipe, it separates a part of the high-temperature airflow and changes the running direction of the yarn by 1800 degrees. , a cold air flow 15 is directed from below to a cooling pipe 16 blowing upward.

There, the thread is cooled while being kept in a relaxed state, passes through a guide 17 and a take-off roller 18, and is wound onto a bobbin 19.

FIG. 3 shows an example of an apparatus for carrying out the present invention, in which the running direction of the thread is changed by 70° using a plate with holes or a wire gauze 14 of a suitable mesh in the thread guiding device, and a low-temperature air stream 15 is used.
is sprayed at 20° to the yarn.

FIG. 4 shows yet another example, in which the thread guiding device is a pipe 14 with holes, and the high-temperature airflow is separated by the holes.
Next, a low-temperature air stream 15 is blown diagonally upward toward the fibers to cool them.

In the apparatus of FIG. 4, the yarn exiting the heating zone is cooled without substantially changing direction.

The above-described apparatus is an example of implementing the method of the present invention, and it goes without saying that the present invention may be implemented using other apparatuses.

FIG. 5 is a schematic diagram showing the morphology of fibers obtained by the method of the present invention and the conventional method.

FIG. 5a shows the result obtained by the method of the present invention, and the crimp is well developed and fixed.

On the other hand, Fig. 5 shows the fiber obtained in Comparative Example 2, which will be described later.
The single fibers are entangled to form a pill-like shape, which causes druffles such as thread breakage during the knitting and weaving process.

In FIG. 5C, on the contrary, the take-up speed is set at a high speed to prevent the formation of fluff, but in this case, the crimps are not fixed, resulting in a yarn with almost no crimps.

The size of overfeed is determined by the speed of the supply roller■1
, the ratio of the speed difference of take-up roller speed ■2 (vl-■2)
It is expressed as /■1.

According to the present invention, for example, the overfeed is 0.1 to 0.
．． 4. Relaxation of latent crimpable yarn at a yarn feeding speed of 3000 m/min It is now possible to stably wind the yarn after heat treatment with sufficient crimp retention, resulting in crimp development. The yarn was a processed yarn with excellent stretchability, good crimpability, and an excellent texture.

EXAMPLES The present invention will be explained below with reference to examples, but the present invention is not limited in any way by these examples.

K, ωSr, CN, [η] in the examples have the following contents.

The expansion/contraction ratio is about 0.05 f? using a measuring machine. /dr tension until it reaches 10,000 dr (500 dr.
0dr) Make a small skein.

After applying an initial load of 1 Or (0,001 P/dr) to a small skein and wetting it with water, it was gently immersed in hot water at 90°C for 30 minutes for a relaxing treatment, and after completion, it was hung on a foot etc. Dry naturally.

After drying, measure the length lo under the initial load of 10f (0,0O1f/dr), then 99oz (0,1g'/dr)
The length of the skein 11 is measured after 30 seconds under the main load (1 kg in total).

Hot water shrinkage rate ωSr Two points are struck at a distance of 500 myx on the sample with an initial load of 0.1 ft/dr.

The initial load was removed and the sample was immersed in hot water at 100°C for 30 minutes.

After air-drying, apply an initial load of 0.1 S'/dr again and measure the length between two points to obtain 1 (m door).

Crimp number CN: Take out the single fiber without applying tension as much as possible, and 5CIfL under a load of o, o5f/dr.
Glue 10 pieces to the frame.

Then, an enlarged photograph is taken and the number of crimp is measured.

Fixed viscosity [η]: For polyethylene terephthalate, the polymer is dissolved in a mixed solvent of phenol and tetrachloroethane at a weight ratio of 1:1 at a ratio of 1/100 CC,
Measured at 30'C.

Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.75 and polyethylene terephthalate with an intrinsic viscosity of 0.55 were mixed into 1
The drawn yarn of 135 denier 32 filaments after being composite spun in a side-by-side type, further drawn, and heat set is guided to a suction ejector and subjected to relaxation heat treatment, and after being relaxed and cooled by the apparatus shown in Fig. 2, the yarn is guided. , it was rolled up via a take-up roller.

Supply roller speed 2000 m/m1n r Take-up roller speed V2m/mi! t Overfit ratio (2000-V2)/2000 Stretching conditions Stretching ratio 3.33 times Heat set temperature 150°C Relaxation heat treatment conditions Substantial temperature in heating zone 180°C, 200°C, 220°C Heating zone length 1.5 m To ejector Supply air flow rate 10.2N7719/
hr Temperature of air supplied to the ejector Room temperature relaxation cooling condition Yarn guiding device Diameter 20mmφ, length 60CrIL, porosity 3
U-shaped pipe cooling pipe diameter with 0% pores: 30 mm φ Cooling pipe length: 1 m Low-temperature air flow Room temperature air (15 to 3 ONi/hr) As shown in Table 1, in this example, at a speed of 2000 m/min. Even when the yarn was fed and the overfeed ratio was increased to 0.35, products with good crimp were obtained in all cases.

Example 2 Up to the relaxation heat treatment process, the conditions were exactly the same as in Example 1, and after the yarn was cooled by the device shown in Figure 3 as the relaxation cooling treatment method, the yarn was passed through a guide and a take-up roller. I let him turn it over.

Relaxed cooling condition Yarn guide device Width 10CrfL, length 60 cm Width 10CrfL Wire mesh plate cooling pipe diameter 30mmφ Cooling tube length 1m Low temperature airflow Room temperature air (15 to 3 ON po/hr) In this example, the smaller the wire mesh plate used in the yarn guide device It is observed that the degree of separation of the high temperature airflow becomes better, and the cooling and fixation of the crimp becomes better.

Example 3 The steps up to the relaxation heat treatment step were carried out under exactly the same conditions as in Example 1, and after cooling the yarn using the device shown in FIG. 4 as the relaxation cooling treatment method, the yarn was passed through a guide and a take-up roller. I let him turn it over.

Relaxation cooling condition thread guide device Diameter: 25 mm φ, length: 60 CrrL Wire mesh cylinder Cooling pipe diameter: 30 mm φ Cooling pipe length: 177 L Low temperature air flow Room temperature air (15 to 3 ONi/hr) 3rd
As shown in the table, even in the method in which the direction of the thread does not change in the thread guiding device, it is recognized that the method in which the porosity of the thread guiding device is controlled is superior in cooling solidification.

Example 4 Polyethylene terephthalate with an intrinsic viscosity of 0.78 and polyethylene terephthalate with an intrinsic viscosity of 0.54 were composite-spun in a bimetallic manner, and then stretched and heat-set.
A drawn yarn of 0 denier 32 filament is guided to a suction ejector at an ultra-high speed of 3000 m/min and subjected to relaxation heat treatment.
After relaxing and cooling using the apparatus shown in FIG. 2, the yarn was passed through a guide and a take-off roller and wound up.

Supply roller speed 3000 m/rnu1 Take-up roller speed V2 m1m1n Overfeed rate (
3000-V2)/000 Stretching conditions Stretching ratio 3.0 times Heat set temperature 170°C Relaxation heat treatment conditions Substantial temperature in heating zone 180°C 5200°C, 220
°C Heating zone length 1.5 m Air flow rate supplied to the ejector 12. ON rd /
hr Supply air temperature to ejector 100'C relaxation cooling temperature Fiber guide device Diameter 20mmφ, length 60CrrL, porosity 3
U-shaped pipe with 8% pores Cooling pipe diameter: 30 mm Cooling pipe length: 1.5 m Low-temperature air flow Room temperature air (15 to 3 ONi/hr) In this example, at an ultra-high speed of 3000 m/min and 0.28 In all cases, crimped yarns with good performance were obtained up to a high overfeed rate.

Comparative Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.75 and polyethylene terephthalate with an intrinsic viscosity of 0.55 in 1:
The drawn yarn of 135 denier 32 filaments, which has been composite-spun into a side-by-side type, further drawn, and heat-set, is guided to a suction ejector and subjected to relaxation heat treatment, and the striations discharged from the heating zone are passed through a guide as they are to a take-up roller. I led him to it and rolled it up.

Supply roller speed 2000m/m Take-off roller speed v2m/rIu! L overfeed rate (2000-V2)/000 Stretching conditions r Stretching ratio 3.33 times Heat set temperature 150°C Relaxation heat treatment conditions Substantial temperature in heating zone 180°C, 200'C1220
°C Heating zone length 1.5m Supply air flow rate to ejector 10.2N771'/
hr Temperature of air supplied to the ejector When attempting to match the overfeed rate at each heating zone temperature as in the case of Example 1 in which room temperature relaxation cooling treatment was performed, the yarn discharged from the heating zone became too slack and was pulled. It was impossible to wind up the paper because it was stuck to the removal roller and a lot of pill-like particles appeared.

Table 5 shows the yarn quality of the fibers obtained with an overfeed rate that allows winding.

All of these fibers had low K and CN values and were insufficiently crimped.

Comparative Example 2 Polyethylene terephthalate with an intrinsic viscosity of 0.75 and polyethylene terephthalate with an intrinsic viscosity of 0.55 were composite-spun in a bimetallic manner, and then stretched and heat-set.
0 denier 32 filament drawn yarn 3000 m/
The yarn was guided to a suction ejector to which air of 12.0 N7719/hr was supplied at a speed of 12.0 N7719/hr for relaxation heat treatment, and the yarn discharged from the heating zone was directly guided to a take-up roller through a guide and wound up.

Since the yarn discharged from the heating zone is cooled by outside air, trying to keep it in a relaxed state results in a high supply speed and a large amount of heated air being discharged, making it impossible to take off the yarn stably. The thread gets tangled or bunched up, and ends up being wound up onto the bobbin.

The shape of the yarn obtained here is as shown in Figure 5, and because there are fluff-like objects as shown in the figure,
When used in woven or knitted fabrics, troubles such as thread breakage frequently occur, which is a serious problem.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a typical example of a conventional relaxation heat treatment apparatus for latent crimpable fibers. FIGS. 2, 3, and 4 are representative examples of apparatus for carrying out the method of the present invention. FIG. 5 is a schematic diagram showing the form of a crimp-generating yarn wound onto a bobbin, in which a is a yarn according to the present invention, b and C are yarns according to a conventional method, 9 is a fiber, 10 is a supply roller,
11 is an ejector, 13 is a heating zone, 13 is a yarn guiding device, 16 is a cooling pipe, and 18 is a take-off roller.

Claims (1)

[Claims] 1a Crimpable fibers are supplied to a heating zone at a rate of 1000771/min or more to develop crimps, and then taken out from the zone, and then a high-temperature air stream is provided in the zone that accompanies the crimped fibers. After running a yarn guiding device having a gap that allows at least a part of the fiber to be discharged, a low-temperature air current in substantially the same direction as the running direction of the fiber is applied to the running fiber, and then the fiber is wound up. Features: High-speed heat treatment method for latent crimpable fibers.