JPS6234856B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tow drawing and post-treatment method. More specifically, the present invention relates to a method for preventing the single yarn from being wrapped around a roller during stretching and post-processing of tow, thereby stabilizing the process and improving quality.

Conventionally, when drawing and post-processing hundreds of thousands or more synthetic fibers like tow at the same time, a single yarn breaks and the cut end wraps around a roller, and this wrapped yarn increases, cutting the tow and causing M /C was forced to stop.

The reason why this phenomenon occurs is that when there is one or more cut yarn parts in the running yarn, when the cut parts pass the surface of the roller, the cut ends drive the yarn. contact with the roller surface,
It is glued and wound around the roller, and when it goes around the roller surface, the wrapping continues to grow due to a stronger binding force, and at the same time, adjacent normal yarns are abnormally rubbed or intertwined and cut, and this becomes a group of wrapped yarns. This is because in addition to this, the roller wrapping grows at an accelerating pace.

When single yarn wraps around the rollers, the machine stops repeatedly, resulting in a decline in the quality of the raw cotton produced.
This resulted in uneven quality, and at the same time, it was not possible to save labor, which was a major obstacle to reducing costs. For this reason, many proposals have been made regarding roller wrapping.

For example, a method in which a knife is installed inside the roller to cut and remove the threads wrapped around the roller (Japanese Patent Publication No. 42-22562
However, this method was a passive method in which the wound yarn was removed.

As a method to more actively prevent roller wrapping, for example, there is a method in which unstretched tow is tied up in a spiral shape with yarn of the same type and property as the tow at a gentle pitch and stretched (Japanese Patent Publication No. 37-9757). However, this method is not suitable for widening the tow width as much as possible, uniform stretching, and uniform heat treatment.

Further, there is a method (Japanese Unexamined Patent Publication No. 103808/1983) in which fluid is injected to the side that contacts the roller immediately before the tow contacts the roller. By proposing this method, prevention of single thread wrapping has been greatly improved. However, since this method involves entangling most of the cut terminal yarn with the surrounding yarn, a large amount of fluid is used per nozzle, and the number of nozzles is required to be equal to the number of rollers. This results in a significant increase in costs, and most of the cut yarn is entangled with surrounding yarns, causing problems due to poor opening during the subsequent cutting and spinning processes, resulting in production problems. This had the disadvantage of causing a decline in quality and quality. As described above, none of the conventional methods has been able to efficiently prevent roller wrapping with a small flow rate and maintain the quality of the resulting product.

A first object of the present invention is to prevent the broken ends of one or more filaments, which occur during the process of drawing and heat treating tow, from wrapping around a roller using a simple device and a small flow rate.

Furthermore, a second object of the present invention is to prevent troubles in the spinning process after cutting and to obtain high-quality spun yarns and fabrics.

The configuration of the present invention that achieves the above object is such that when the tow is brought into contact with the rollers and transferred, an angle of 5 to 55 degrees with respect to the running direction of the tow is made from a direction opposite to the running direction of the tow before the tow is brought into contact with the rollers. This is a method of preventing the tow from wrapping around the roller by spraying air. Furthermore, there is a toe that allows air to be injected.
It is effective to heat the tow to a temperature higher than Tg (glass transition point), apply a tension of 0.1 g/d or higher, and to spray air from both sides of the tow.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for preventing roller wrapping according to the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a preferred embodiment of the tow drawing or heat treatment method according to the present invention,
The drawn or heat-treated tow 1 passes through a region of air 3 ejected from an air injection nozzle 2 and is transported by rollers 4. The tow with its cut end before passing through the basin is shown in FIG.

The above-mentioned tow has cut ends A, B and a restraint point C due to intertwining of fibers, etc. In particular, the cut end A is involved in winding around the roller, and the cut end B is not involved in the winding. The tow after passing through the region of the air 3 to be injected is shown in FIG. In the present invention, most of the cut edge A is bent from the restraint point C by injecting air from the direction opposite to the running direction of the tow, and most of the cut edge A becomes the cut edge B. This results in a terminal that is not involved in roller wrapping. In order to facilitate the bending of the cut end A and to make the flow rate small and economically advantageous, the tow is preferably heated to a temperature of Tg or higher, and more preferably Tg + 10°C or higher.

The tension of the tow is set at 0.1 g/d (the filament that makes up the tow Tension per piece) or more, preferably
0.25g/d or more, more preferably 0.40g/d
That's all.

In order to more reliably and economically prevent roller wrapping, the arrangement of the air injection nozzles and the direction of air injection are particularly important. Therefore, it is necessary to regulate the spray angle of the nozzle within the following range. In other words, air is injected toward the tow in the opposite direction to the tow's advancing direction, and the angle between the tow's advancing direction and the air injection direction (the nozzle injection angle) is set to 5.
The angle should be ~55°. This is because if the angle is less than 5°, the cut ends involved in roller wrapping tend to bend, and although this is effective in preventing wrapping, the distance between the nozzle and tow inevitably increases, reducing the flow velocity of the injected air and requiring an increase in the flow rate. This is not desirable because it causes On the other hand, if the angle exceeds 55 degrees, most of the cut ends will not be bent and will be loosely wrapped around the surrounding fiber bundles, as shown in Figure 3.

If the fibers are wrapped in this way, shrinkage spots, fiber length unevenness, and fiber opening defects will occur during staple production, resulting in decreased productivity in the spinning process and deterioration of the quality of the spun yarn and fabric, which is undesirable. Preferably, it is 10° to 35°.

It is essential to provide at least one nozzle 2 in the thickness direction of the tow, but when the tow is transferred at a high speed or the tow is thick, two nozzles may be provided on both sides of the tow to prevent the tow from wrapping. can be achieved more effectively.

By providing the second nozzle, the winding of the single yarn is reduced, but the injection direction of the second nozzle must be set under the regulated conditions as described in detail above, that is, when the tow is sprayed from the opposite direction of the tow and the running direction of 5
When air is injected at an angle of ~55°, the effect of preventing winding is significant.

Furthermore, attach the second nozzle so that it is symmetrical with the first nozzle based on the toe.
Figure), the anti-wrapping effect is even more remarkable.

The fiber bundle obtained by the present invention is characterized by a method in which the cut single yarns are folded starting from a restraining point such as entanglement between the single yarns, and the method efficiently and almost completely prevents wrapping around the roller. This increases the degree of freedom in terms of conditions that can be adopted in the spinning process, such as increasing the height of the yarn, making it possible to achieve higher quality.

Since roller wrapping is drastically reduced, costs are reduced and quality is greatly improved.

Do not affect uncut fibers in any way.

This is a significant improvement in productivity, product quality, and product quality not only in the silk spinning process but also in higher-order processing processes.

Therefore, when the present invention is applied to a fine denier polyester tow with a single yarn fineness of 2 ^d or less, especially a cotton-mixed polyester that requires high Young's modulus and high strength, and a low polymerization degree polyester tow, the effect is remarkable.

In the present invention, air is used because of its economic efficiency, anti-tangling effect, and ease of handling. Further, the air injection nozzle preferably has a nozzle shape that injects air over the entire tow width, as shown in Japanese Patent Application Laid-open No. 103808/1983.

As the polymer species constituting the tow that can be used in the present invention, any synthetic polymer such as polyester, polyamide, polyacrylonitrile, polyolefin, etc. may be used.

Further, the present invention can be carried out in any step of yarn spinning, including a tow temperature of Tg or higher, a stretching zone where stretching is substantially completed where a tension of 0.1 g/d or higher is applied, and a stretching zone where a stretching tension is applied. , a heat treatment zone is preferred after the tension heat treatment and in which the heat treatment tension is acting.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto.

In addition, Tg in the examples refers to PERKIN.
Using an ELMER differential calorimeter, the heating rate was increased to 16
The measurements were taken under the condition of ℃/min, and the sample used was an undrawn yarn.

Example 1 Tg is 71℃, single yarn fineness 5.2 _d , tow fineness
An unstretched polyester tow of 1750000 ^D was steam-stretched at 3.51 times, then subjected to a tension heat treatment of 2.6% for 5 seconds at 205°C, and an air injection nozzle with a length of 450 mm and a width of 0.5 mm was inserted into the tow in front of the draw roller immediately after the heat treatment. They were placed above and below the tow, making an angle of 10° with the direction of tow movement, and were installed so that air was injected in the opposite direction to the direction of tow movement. The toe temperature at this time was 182℃
The tension was 1.6 g/d. The distance between the tow and the nozzle is 10 mm both at the top and bottom, and 4Kg/cm ² is applied to this nozzle.
of compressed air was sent in.

The tow was further crimped in a staff box, heat-set at 110° C. for 20 minutes, and then cut to a fiber length of 38 mm.

At this time, the wrapping around the roller after the tension heat treatment was 0.35 times/1000 kg. Furthermore, the raw cotton obtained had no neps or overlong fibers, and had good opening properties.

Comparative Example 1 The same unstretched polyester tow as in Example 1 was stretched under the same conditions except that no air injection nozzle was provided, and after stretching, tension heat treatment, densification, and heat setting, it was cut to a length of 38 mm.

At this time, the wrapping around the roller after tension heat treatment is
The weight was 12.6 times/1000Kg, and constant monitoring was required.
In addition, the machine operation rate was 83% of that in Example 1 due to the machine stopping due to the wrapping. Furthermore, the raw cotton contained many neps and was of low quality.

Comparative Example 2 The same unstretched polyester tow as in Example 1 was used, except that the air injection nozzle was installed so that the angle between the tow's traveling direction and the tow's traveling direction was 65° C., and the air was jetted in the opposite direction to the tow's traveling direction. Stretched under the same conditions as in Example 1, tension heat treated, and heat-set after applying shrinkage38
It was cut to a cutting length of mm. At this time, the wrapping around the roller after tension heat treatment is 4.2 times/1000Kg
Therefore, constant monitoring was necessary. In addition, the machine had to be stopped due to frequent occurrence of wrapping, and the operating rate of the machine was 92% of that in Example 1. The raw cotton obtained had neps scattered and was of low quality.

Example 2 The same undrawn yarn as in Example 1 was used, except that the drawing ratio was changed to 3.73 times, and drawing, tension heat treatment, shrinkage application, and cutting were performed under the same conditions.

As in Example 1, an air injection nozzle was provided to prevent wrapping after the tension heat treatment, and a similar nozzle was also provided in front of the draw roller after stretching to prevent the cut ends from wrapping during stretching and tension heat treatment. The wrapping status of the draw roller after stretching and the draw roller after tension heat treatment is 0.61 times/each.
1000Kg 0.26 times/1000Kg. Raw cotton physical properties are strength
It had an elongation of 7.45 g/d and an elongation of 20.3%. The raw cotton obtained was of high quality and free of neps.

Comparative Example 3 The same unstretched polyester tow as in Example 1 was used, and yarn spinning was carried out under the same conditions as in Example 2.

However, no nozzle to prevent wrapping after stretching was provided.

Winding around the draw roller after stretching occurred frequently, making it impossible to continue stretching. The stretching ratio was lowered to a stretching ratio of 3.51 at which stretching was possible. After stretching, raw cotton was obtained under the same conditions as in Example 1. Strength of raw cotton
It was a low-grade raw cotton with low strength of 6.95 g/d and elongation of 27.5% and many neps.

[Brief explanation of the drawing]

FIG. 1 is a schematic process diagram of the present invention, and FIGS. 2 and 3 are schematic diagrams showing the state of the cut end of the filament constituting the tow before and after air treatment, respectively. 1: Tow, 2: Air injection nozzle, 3: Air injection, 4: Transfer roller, AB: Cut end, C: Restraint point.

Claims (1)

[Claims] 1. When the tow is brought into contact with the rollers and transferred, air is blown from a direction opposite to the running direction of the tow at an angle of 5 to 55 degrees with the running direction of the tow before the tow comes into contact with the rollers. A method for preventing tow from being wrapped around a roller, characterized by spraying the tow. 2. The method for preventing tow from being wrapped around a roller according to claim 1, wherein the tow to which air is blown is heated to a temperature higher than Tg (glass transition point). 3. The method for preventing tow from being wrapped around a roller according to claim 1, wherein the tow to which air is blown is subjected to a tension of 0.1 g/d or more. 4. A method for preventing tow from being wrapped around a roller according to claim 1, characterized in that air is injected from both sides of the tow in the thickness direction.