JPH08325853A - Method for producing polyester fiber - Google Patents

Abstract

(57) [Summary] [Purpose] In a method for producing a polyester fiber in which a spun yarn is once cooled to a glass transition temperature or lower and then reheated and stretched, mechanical properties, an oil agent adhesion rate, and an oil agent utilization rate are excellent. Moreover, it provides a manufacturing method with less scattering of the oil agent. [Structure] The spun polyester fiber is once cooled to a glass transition temperature or lower, and the cooled yarn is passed through a heating zone to heat-draw the yarn in a non-contact state, and then the yarn is drawn. A method for producing a polyester fiber, wherein the diameter is 4 mm or more and 10 mm.
The viscosity at the time of applying an oil agent to the yarn is 5 cm St or more and 10 cm S on the downstream side that is 10 cm or more and 40 cm or less away from the yarn outlet of the heating zone having the yarn outlet that is the following.
A method for producing a polyester fiber, which comprises bundling while applying an oil agent of t or less, and collecting at a speed of 3000 m / min or more and 6000 m / min or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester fiber, in which a spinning oil agent is less scattered in a spinning step and the oil agent adheres to a yarn in a good condition.

[0002]

2. Description of the Related Art Conventionally, various manufacturing methods have been proposed for the purpose of reducing the cost for manufacturing polyester fibers and saving energy. For example, in JP-B-45-1932, a yarn spun from a spinneret is once cooled to a glass transition temperature or lower,
A method of reheating and hot drawing has been proposed. And
As a yarn heating device used in such a process,
It is generally used to heat a yarn which is surrounded by a heated cylinder wall and travels in a non-contact manner.

By the way, when the spun yarn is guided into the heating cylinder in a non-focused state, the air flow accompanying the running yarn flows into the heating cylinder, thereby significantly reducing the heating efficiency of the yarn. It has a problem of causing it. Therefore, JP-A-5
In Japanese Patent Laid-Open No. 4-138613, there is proposed a method of concentrating the yarns immediately before entering the heating cylinder and further providing a device for removing the associated airflow of the yarns, thereby eliminating the adverse effect caused by the associated airflow. ing. However,
In such a method, since the yarns are bundled, the heating efficiency is lowered, and moreover, the running yarns are stick-slip due to the guide used to bundle the yarns, resulting in single fiber breakage or stretch unevenness. It had a problem of causing it.

Therefore, in Japanese Unexamined Patent Publication No. Sho 60-209012, by introducing an appropriate amount of heated gas from the upper part of the heating cylinder together with the unfocused yarn, a yarn which reduces the influence of the accompanying air flow is disclosed. Heating methods have been proposed. However, with such a method, it is difficult to rectify the heated gas to be introduced, and on the contrary, it causes the shaking of the yarn, which causes the denier unevenness of the yarn.

As a heating method (apparatus) for solving the above-mentioned problems, Japanese Patent Laid-Open No. 62-205294 has been proposed.
In Japanese Patent Laid-Open Publication, without introducing a heated gas that causes yarn sway, and yet preventing an air flow associated with the yarn in a non-focused state, thereby reducing the yarn heating efficiency of the heating device, Methods have been proposed for heating running yarns. However, in the method proposed in Japanese Unexamined Patent Publication No. 62-69816, no attention is paid to the influence of hot air flowing out from the heating device together with the traveling yarn on the application of the oil agent to the yarn. Not not. In Japanese Patent Laid-Open No. 54-138613 mentioned above, a method is proposed in which an oil agent is applied and the yarns are converged to remove the associated airflow to the yarns before the yarns enter the heating zone. As described above, this method involves various problems.

Therefore, the inventor of the present invention has proposed the above-mentioned Japanese Patent Laid-Open No. 62-
An attempt was made to apply the oil agent in the vicinity of the heating device by the method proposed in 205294. However, due to the yarn accompanying flow flowing out from the yarn outlet of the heating device, the flow of the oil agent is unevenly distributed, which makes it difficult to sufficiently attach the oil agent to the yarn, and the scattering of the oil agent may cause the surrounding work environment to be disturbed. I faced the problem of making it worse. A further problem was that if an oil agent was applied at a position close to the yarn outlet of the heating device, it would be difficult to cool the high-temperature yarn that has come out of the heating zone and has not yet been sufficiently cooled. When the oil agent used for the above was used, the new problem that the adhesion unevenness of an oil agent arises was faced.

[0007]

The problems to be solved by the present inventor are as follows in view of the new problems described above.

That is, in the polyester fiber spinning step, the spun yarn is once cooled below the glass transition temperature without being focused by a guide or the like, and then the yarn is reheated. It is to minimize the scattering. Then, even if the unfocused yarn is not focused by the hot air flowing out from the yarn outlet of the heating device and the yarn is first focused by the guide, the adhesion rate of the oil agent does not decrease, and adhesion unevenness occurs. You can apply a uniform oil so that there is no
It is an object of the present invention to provide a method for producing a polyester fiber having excellent mechanical properties such as strength and elongation.

[0009]

According to the present invention, the thermoplastic polyester fiber spun from the spinneret is once cooled to the glass transition temperature or lower while maintaining the unfocused state during spinning. By passing the cooled yarn into the heating zone of the closed system except the yarn inlet / outlet, the yarn is heated and drawn in a non-contact state, and then the yarn is focused. The method for producing a polyester fiber according to claim 1, wherein the yarn outlet of the heating zone has a yarn outlet having a diameter of 4 mm or more and 10 mm or less.
On the downstream side separated by 0 cm or more and 40 cm or less, the yarn is converged while applying the oil agent having a viscosity of 5 cm St or more and 10 cm St or less when the oil agent is applied, and 3000 m / min or more, 6
A method for producing a polyester fiber is provided, wherein the polyester fiber is collected at a speed of 000 m / min or less.

[0010]

The present invention will be described in more detail below.

First, the thermoplastic polyester of the present invention is mainly intended for a polyester having ethylene terephthalate as a main repeating unit, but may be a polyester having butylene terephthalate as a repeating unit. Further, it may be a polyester obtained by copolymerizing one or more kinds of other components in an amount of 15 mol% or less and a polyester containing a small amount of additives such as a matting agent, a colorant and an antioxidant.

Next, in the present invention, the spun fiber (yarn) is once cooled below the glass transition temperature,
It is important in forming the basic internal structure of the fiber, and then it is important to introduce the cooled yarn into the heating zone in an unfocused state and heat-draw.

However, if the yarn is simply passed into the heating zone, as described above, since the yarn is in the unfocused state, a large amount of the heated air flow is generated around the yarn as compared with the focused state. Will be accompanied. For this reason, the application of the oil agent to the yarn is not successful due to the effect of the accompanying air flow, and there arises a problem that the adhesion rate of the oil agent to the yarn decreases and uneven adhesion occurs.
As described above, this causes breakage of the single fibers and scattering of the oil agent to deteriorate the working environment.

In order to solve this problem, in the present invention,
The diameter of the yarn outlet of the heating zone is 4 mm or more and 10 mm or less. As described above, by narrowing the yarn outlet diameter of the heating zone, the heating airflow accompanying the yarn can be minimized, and problems such as oil agent adhesion unevenness, reduction of oil agent adhesion amount, and oil agent scattering are caused. It can be resolved.

However, as a side effect of narrowing the yarn outlet diameter, the yarn converging position comes very close to the heating zone, and if an oil agent is applied at this converging position, the heated yarn is heated. The strip comes into direct contact with the oil agent. For this reason, if the conventional oil agent is used as it is, it only causes a new problem such as a decrease in the oil agent adhesion rate of the yarn, uneven application of the oil agent, and scattering of the oil agent. It was

[0016] With respect to this new problem, the present inventor narrows the yarn outlet diameter from the heating zone so that the oil agent is applied to the yarn even when the yarn converging position is brought close to the yarn outlet. We have diligently studied how to make it uniform. as a result,
The inventors have found that this problem can be solved by setting the viscosity of the oil agent within a specific range, and finally reached the present invention. That is, simply, a viscosity larger than that of a commonly used oil agent (1 to 4 cm St), that is, 5 to 1
The inventors have found that the above problem can be subtly solved simply by setting 0 cm St.

That is, by narrowing the yarn outlet diameter of the heating zone, the air flow associated with the yarn is reduced, whereby the unevenness and scattering of the oil agent caused by the associated flow are satisfactorily eliminated, and the yarn is It was possible to solve the problem of non-uniform application of the oil agent to the heated yarn, which was a secondary problem caused by squeezing the outlet.

[0018]

EXAMPLES Examples of the present invention will be described in detail below.

FIG. 1 is a schematic front view (a part of which includes a cross section) illustrating a spinning process for producing the polyester fiber of the present invention.

In the figure, 1 is a spin block, 2 is a spinneret, 3 is a spinning yarn cooling device, 4 is a non-contact type heating cylinder, 5 is a heater, 6 is a yarn outlet, and 7 is an oil agent application. Device, 8 and 9 are take-up rollers, 10 is an interlacing device,
11 represents a winding machine, respectively.

In the figure, the polyester polymer is spun from a spinneret (2) attached to a spin block (1) into a fiber, and once cooled to a glass transition temperature or lower by a cooling device (3). After that, it passes through the heating zone surrounded by the heating cylinder (4) which is a substantially closed system except the inlet and outlet of the yarn in an unfocused state. At this time, the spun yarn (Y) is heated and drawn in the heating zone. The temperature of the heating zone is preferably higher than the glass transition temperature of the polyester polymer. In order to realize this, the wall surface of the heating cylinder (4) is heated to 150 to 3 by a heater (5).
Heat to 00 ° C. Here, as the heater (5), known methods such as an electric heating type, a heating medium heating type, and a high frequency heating type can be used.

Thus, the yarn drawn by heating is
The heating cylinder (4) heated by the heater (5)
4 ~ 10mm in diameter, passing through the heating zone surrounded by
It comes out together with the heated yarn accompanying stream from the yarn outlet (6) that is narrowed down. And 10 cm or more from the heating zone,
At a position of 40 cm or less, it is focused while being refueled by the oil agent applying device (7). At this time, the yarn exiting the heating zone is rapidly cooled, but since it is still at a high temperature, if an ordinary oil agent having a viscosity of 1 to 4 cmSt is used as it is, the oil agent may cause adhesion unevenness. , The viscosity of oil is 5
It is adjusted to 10 cm St. As a method of applying the oil agent to the yarn, an oiling roller type, a spraying type, an oil supply guide type, etc. can be used, but the oiling guide type oiling has a small running resistance of the yarn and the amount of the oil agent is fixed. However, it is preferable because it has the advantage that it can be supplied.

Here, if the yarn outlet diameter (diameter) of the heating zone is less than 4 mm, the yarn is likely to come into contact with the yarn outlet, which is not preferable because it is scratched and damaged. On the other hand, if it is 10 mm or more, the heated yarn-associated airflow coming out from the yarn outlet increases, and this influences the unevenness of adhesion of the oil agent, which is not preferable.

Further, as a position for focusing while supplying oil to the yarn, 10 to 40 cm downstream from the yarn outlet of the heating zone is suitable, and if it is less than 10 cm, it comes out together with the yarn from the yarn outlet. The influence of the accompanying air flow cannot be ignored, and it causes unevenness of oil agent adhesion. On the other hand, if it exceeds 40 cm, the yarn outlet diameter cannot be reduced sufficiently and the yarn may come into contact with the yarn outlet, which is not preferable.

Further, with respect to the viscosity of the oil agent, it is preferable to adjust it to 5 to 10 cmSt, and if it is less than 5 cmSt, the viscosity of the oil agent is lowered by the heat carried by the yarn, and the effect of suppressing the scattering of the oil agent is obtained. Is decreased, which is not preferable. On the other hand, if it exceeds 10 cm St, the resistance when the yarn passes increases, which is not preferable.

Incidentally, these conditions are yarn manufacturing conditions,
That is, since it depends to some extent on the number of filaments, denier of single fiber, etc., it may be appropriately set within the above range.

In this way, finally, the yarn is moved at a constant speed by the take-up rollers (8 and 9) to a take-up speed of 3
It is collected at 000 m / min or more and 6000 m / min or less, and subjected to entanglement treatment by the yarn entanglement treatment device (10),
It is wound by the winder (11). Here, the take-up speed is 3
If it is less than 000 m / min, the manufacturing cost of the yarn is not sufficiently reduced, and if it exceeds 6000 m / min, stable yarn production is difficult.

Here, the take-up rollers (8 and 9) described above are used.
In addition, although two rollers are used in combination in the present invention, the present invention is not limited to this.
You may use more than one. Further, by appropriately selecting the manufacturing conditions, the winding may be performed directly without using the take-up roller. However, it is preferable to use these take-up rollers in order to maintain stable manufacturing conditions. It is also possible to install a group of take-up rollers, further draw the yarn between these rollers, and then wind the yarn.
Further, the entanglement treatment may be performed not while being performed on the downstream side of the take-up roller, but while adjusting the tension of the yarn between the take-up rollers (8) and (9).

The above is the conditions applicable to the examples in general, but the examples relating to the method for producing the polyester fiber of the present invention will be described below by giving specific numerical values. The physical property values used in the description at this time will be described below. The measuring method will be described first.

[Strength and Elongation] Using a Tensilon tensile tester manufactured by Toyo Baldwin Co., Ltd., a yarn sample was sampled so that the sample length would be 200 mm, and the tensile test speed was 10%.
A tensile test was performed at 0 mm / min to determine the strength and elongation.

[Oil Agent Adhesion Rate] About 5 g of a thread sample was collected, dried, and then weighed to obtain its weight (Wg).
I asked. Then, the ridges are ultrasonically cleaned in a room temperature cleaning solution containing 0.5 g of synthetic detergent for 3 minutes and washed with water to sufficiently remove the oil agent adhered to the ridges. Dried. And the weight of the drip after drying (W '
g) is weighed, and the weight difference (W-W ') before and after washing is obtained,
This value was divided by W'and expressed as a percentage.

[Oil agent utilization rate] A fixed amount of the oil agent is supplied to the oil agent application guide, the amount of the oil agent discharged within a fixed time is measured while the yarn is not running, and the effective oil agent component amount excluding water is measured. Converted to. Then, the effective oil agent component supply amount per unit length of the yarn calculated from the take-up speed is calculated and divided by the oil agent adhesion amount per unit length of the yarn calculated from the above oil agent adhesion rate. , This is expressed as a percentage.

Example 1 Polyethylene terephthalate was treated at 290 ° C. using the apparatus having the structure shown in FIG.
Was melted and was spun according to a standard method at a discharge rate of 1.1 g / min per hole from a spinneret (2) having 36 discharge holes (hole diameter 0.2 mm). The wind speed of the yarn spun by the yarn cooling device (3) is 25 m /
For one minute, a side blowing cooling air having a temperature of 20 ° C. was blown for 1 m to once cool the glass transition temperature (room temperature) or lower. Then, the yarn thus cooled was passed into the heating zone in an unfocused state. At this time, the heating cylinder (4) used had a length of 1.5 m and an inner diameter (diameter) of 15 mm, and was arranged so that the yarn inlet was 2 m downstream from the position just below the spinneret. And, the heating cylinder wall surface 2
By heating to 30 ° C., the yarn was maintained in a non-contact state with the heating wall, and the yarn was heated. For the yarn outlet (6) of the heating cylinder, as shown in Table 1, shutters having various diameters were prepared and experiments were conducted.

A predetermined distance (30 cm) from the yarn outlet to the downstream side of the yarn from the yarn outlet of the heating cylinder (6).
By the guide-type oil agent applying device installed only separated by
Viscosity at 20 ° C is 9.3 cmSt, viscosity at 40 ° C is 6.2 cmSt, viscosity at 60 ° C is 5.2 cmSt.
While applying a 22% emulsion oil having a viscosity characteristic of Then, while performing the entanglement treatment between the take-up rollers (8) and (9), the take-up rollers were taken at 5000 m / min, and the total denier was 70 denier,
A multifilament having 36 filaments was wound by a winder (11).

Table 1 shows the strength and elongation of the yarns obtained at this time, the oil agent adhesion rate, and the oil agent utilization rate.

[0036]

[Table 1]

As is clear from the table, in the experimental examples (Nos. 2 to 4) in which the diameter of the yarn outlet (indicated as "the yarn passage port" in Table 1) is 4 to 10 mm, the comparative example ( As in No. 1), the yarn was not damaged by coming into contact with the yarn outlet (yarn passage port), so the mechanical properties (strength and elongation) were excellent. However, in the comparative example (No. 4), the diameter of the yarn outlet (yarn passage port) is as large as 15 mm, as compared with the examples (No. 2 and 3), so the yarn coming out of the heating cylinder (4) Due to the influence of hot air that came out with the strip, the oil agent attachment rate and the oil agent utilization rate were low. At this time, when the surface temperature of the oil agent applying guide of the oil agent applying device (7) was measured, the experimental examples (No. 1 to 3) were 42 to 44 ° C, but the comparative example (No. 4) was It was as high as 73 ° C., and it was presumed that the viscosity of the oil agent was clearly lower than the viscosity during use under normal conditions. Then, the spray-like scattering of the oil agent, which is considered to have an influence on this, was also visually observed.

The diameter of the yarn outlet (6) of the heating cylinder (4) is set to 5
A yarn of 70 denier and 36 filaments was prepared under the same conditions as in the example except that the distance from the yarn outlet (6) to the oil agent applying device (7) was set as shown in Table 2. Obtained. Table 2 shows the tenacity and elongation of the yarn, the oil agent adhesion rate, and the oil agent utilization rate obtained at this time.

[0039]

[Table 2]

As is clear from the table, the distance from the yarn outlet (6) of the heating cylinder (4) to the oil agent applying device is 10 to 4
The samples obtained under the condition of 0 cm (Nos. 7 to 9) had good strength and elongation, oil agent adhesion rate, and oil agent utilization rate. However, the distance is less than 10 cm No. 5
In Nos. 6 and 6, although the strength and elongation were good, only the low oil agent adhesion rate and the low oil agent utilization rate were obtained. At this time, the surface temperature of the oil application guide is 40 to 45 ° C. in No. 7 to 11.
On the other hand, the surface temperature of No. 5 was 89 ° C. and that of No. 6 was 65 ° C., and the sprayed oil agent was visually observed to be scattered. Also, the distance is 40 cm
In Nos. 10 and 11, which exceeded the range, the oil agent adhesion rate and the oil agent utilization rate were good, but the yarn contacted the yarn outlet (6), and this caused scratch damage to the yarn, resulting in strong elongation. I only got a low degree. Further, accumulation of polymer shavings was observed in the oil agent applying device with the passage of time, and gelling scum of the oil agent, which was considered to be caused by contact with the oil agent applying device having a high temperature, was also observed.

[Comparative Example 1] As an oil agent applied to the yarn from the oil agent applying device (7), the viscosity at 20 ° C was 2.2 cmSt, the viscosity at 40 ° C was 1.4 cmSt, and 60 ° C. 12% with viscosity characteristics that the viscosity of 1.0 cm St
A 70-denier 36-filament yarn was obtained under the same conditions as in Experimental Examples (Nos. 2 and 3) except that the emulsion oil was used. As shown in Table 3, in each of the experimental values (Nos. 12 and 13), the various physical properties showed that the oil agent was largely scattered, and the oil agent adhesion rate and the oil agent utilization rate were extremely low.

[0042]

[Table 3]

[Embodiment 2] The diameter of the yarn outlet (6) of the heating cylinder (4) was 5 mm, the distance from the yarn outlet (6) to the oil agent applying device (7) was kept constant at 25 cm, and the take-up was performed. Other than changing the speed and discharge rate as shown in Table 4 below,
Under the same conditions as in "Example 1", a yarn of 70 denier and 36 filaments was obtained. At this time, the strength and elongation of the obtained yarn,
Table 4 shows the oil agent adhesion rate and the oil agent utilization rate.

[0044]

[Table 4]

As is clear from the table, the take-up speed is 3
In the experimental example (No. 14) lower than 000 m / min, the strength of the yarn obtained by passing through the heating zone was as low as 3.1 g / d,
It was not practical. However, the experimental example (N
15 to 17), the strength was 3.8 to 4.7, which was a level that was sufficient for practical use.

[0046]

As described above, in the present invention, the yarn outlet of the heating zone is narrowed, and the yarn is bundled while supplying the oil agent at an appropriate position downstream from the yarn outlet. The device is designed so that it can be collected at a collecting speed of 3000 to 6000 m / min. Therefore, the strength and elongation, the oil agent adhesion rate, and the oil agent utilization rate are excellent, and the problem that the oil agent is scattered around and the working environment is deteriorated can be solved.

Furthermore, the polyester fiber obtained by the present invention has substantially the same properties as the conventional drawn yarn obtained by a method different from that of the present invention.
It has a remarkable effect that it can be used in all fields where the drawn yarn is used.

[Brief description of drawings]

FIG. 1 is a schematic front view (a part of which includes a cross section) for explaining a manufacturing method of the present invention.

[Explanation of symbols]

 1 Spin Block 2 Spinneret 3 Cooling Device 4 Heating Cylinder 5 Heater 7 Yarn Outlet 8, 9 Take-up Roller 10 Entanglement Processing Device 11 Winder

Claims (1)

[Claims] 1. A thermoplastic polyester fiber spun from a spinneret is once cooled to a glass transition temperature or lower, and the cooled yarn is removed from the inlet and outlet of the yarn while maintaining a non-focus state during spinning. A method for producing a polyester fiber, wherein the yarn is heated and drawn in a non-contact state by passing the yarn into a heating zone of a substantially closed system, and then the yarn is bundled. 10 cm or more, 40 c from the yarn outlet of the above-mentioned heating zone having a yarn outlet having a diameter of 4 mm or more and 10 mm or less
On the downstream side at a distance of m or less, the yarn is converged while applying an oil agent having a viscosity of 5 cm St or more and 10 cm St or less at the time of applying the oil agent, and collected at a speed of 3000 m / min or more and 6000 m / min or less. A method for producing a polyester fiber, comprising: