JPH07268725A - Method for high-speed spinning of polyester fiber - Google Patents

Abstract

PURPOSE:To provide a method for high-speed spinning of polyester fibers by which the inflow of an accompanying air stream into a cylindrical heating unit can be controlled, a yarn can efficiently be heat-treated in the unit and the polyester fibers excellent in performances of yarn quality without any size unevenness can be produced at a high speed with good operating efficiency. CONSTITUTION:This method for high-speed spinning of polyester fibers is to carry out the melt spinning from a spinneret having a spinning hole group divided into >=3 groups, freely detachably install a narrowing guide 5 having 5-25mm caliber at an inlet of a cylindrical heating unit 4, provide an aspirator 6 for threading under the guide and regulate the internal temperature of the cylindrical heating unit to 150-250 deg.C, in a method for high-speed spinning of the polyester fibers by once cooling filaments (Y) melt spun from a spinneret (L) to a temperature of the glass transition point or below, then running the resultant yarn in the cylindrical heating unit 4, heat-treating the yarn, subsequently applying an oil thereto with an oil applicator 7 and taking off the oiled yarn at >=4000m/min. Since the caliber of the narrowing guide can simply be changed, the accompanying air stream can readily be controlled at a low cost.

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 having less fineness unevenness and excellent yarn quality at a high speed by a direct spinning drawing method.

[0002]

2. Description of the Related Art Conventionally, a thermoplastic polymer is melt-spun, cooled once to a temperature below the glass transition point, and then the yarn is run in a tubular heating device heated to an internal temperature of 150 to 250 ° C. There have been proposed various direct spinning and drawing methods for producing a yarn having a performance comparable to that of a drawn yarn obtained by a usual low speed two-step method by heat-treating and then taking it off at a high speed.

However, in the direct spinning and drawing method utilizing these tubular heating devices, when the melt-spun yarn enters the tubular heating device, an accompanying air flow flows into the tubular heating device together with the yarn. Therefore, the internal temperature of the tubular heating device is lowered or the internal temperature becomes non-uniform. As a result, there are problems that the thermal efficiency of the yarn is reduced and the air flow is disturbed, the performance of the obtained yarn is degraded, and the fineness unevenness occurs.

As a means for solving this problem, Japanese Patent Application Laid-Open No. Sho 61 has been proposed.
JP-A-215714 proposes a method in which the inlet and outlet of a tubular heating device are narrowed down to control the inflow of an accompanying air flow to improve the thermal efficiency of the yarn. However, since the diameters of the inlet and the outlet of the tubular heating device are narrowed, there is a drawback that threading is difficult. Further, Japanese Patent Application Laid-Open No. 62-69816 proposes a method in which the inlet portion of a tubular heating device has a two-layer structure to regulate the inflow of associated airflow. However,
In this method, since the main body of the tubular heating device is modified to control the inflow of the accompanying airflow, there is a problem that the cost for the modification is high, the threading is difficult, and the workability is poor. .

Further, in Japanese Patent Laid-Open No. 5-98505, a tubular heating device is provided with a squeezing device having an aspirator at the yarn outlet of the tubular heating device to simplify threading and squeeze the lower part. A proposal has been made to reduce the loss of heated air in the inside, and further, in JP-A-5-230710, a tubular heating device is processed, and a jet gas is sprayed onto the yarn at the inlet to remove the air inside the tubular heating device. A method for blocking the inflow of an accompanying air flow into the air has been proposed.

However, in the method disclosed in Japanese Unexamined Patent Publication No. 5-98505, the threading is simplified by using the aspirator, but since the structure is squeezed only at the lower part, the spun yarn is not bundled and is heated in a cylindrical shape. When introduced into the device, the inflow of the accompanying air flow becomes large, which causes turbulence of the air flow in the tubular heating device. Further, when the air is drawn at a high speed, the inflow of the accompanying airflow becomes larger, so that the turbulence of the airflow in the apparatus also becomes large, and fineness unevenness or the like occurs in the obtained fiber. Japanese Patent Laid-Open No. 5-
The method of spraying the jet gas onto the yarn described in JP-A No. 230710 increases the cost due to the processing of the tubular heating device, and when taking it at a high speed, it is necessary to increase the jet speed of the gas. Therefore, the damage to the undrawn yarn is large, which causes a decrease in yarn quality performance. Further, it is necessary to constantly spray the jet gas in order to control the associated air flow, which causes a problem of high manufacturing cost.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, can easily control the inflow of an entrained airflow, has good working efficiency, and can obtain a high-quality polyester fiber free from unevenness of fineness at a low cost. It is a technical object to provide a high-speed spinning method by a direct spinning and drawing method that can be performed.

[0008]

The present inventors have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention, once the yarn melt-spun from the spinneret is once cooled to a temperature not higher than the glass transition point, then run in a tubular heating device and heat treated, and then an oil agent is applied,
In the high-speed spinning method that draws at a speed of 4000 m / min or more, melt spinning is performed from a spinneret in which the spinning hole group is divided into three or more groups, and a throttle guide with a diameter of 5 to 15 mm is detachably provided at the inlet of the tubular heating device. An aspirator for threading is installed below the guide to keep the internal temperature of the tubular heating device at 150
The gist is a high-speed spinning method for polyester fibers, which is characterized in that the temperature is set to ˜250 ° C.

The present invention will be described in detail below. FIG. 1 is a schematic process diagram showing one embodiment of the high-speed spinning method of the present invention, FIG. 2 is an enlarged end view showing one embodiment near the inlet of a tubular heating device, and FIG. 1 is a plan view showing an embodiment of a spinneret used in the high-speed spinning method of the invention.

First, the polyester yarn Y melt-spun from the spinneret 1 is heated in the heating region of the heating cylinder 2 and then cooled to a temperature below the glass transition point by cooling air blown from a cooling device 3. It The cooled yarn Y is bundled by the squeeze guide 5, heat-treated in the tubular heating device 4, bundled and oiled by the oil agent applying device 7, and taken by the first roller 8. Then, the yarn Y is heat-treated by the heat treatment device 10 provided between the first roller 8 and the second roller 11, is entangled by the entanglement treatment device 9, and then is wound by the winding device 12.

In the present invention, first, it is necessary to perform melt spinning from a spinneret in which the spinning hole group is divided into three or more groups. This is to improve the effect of cooling the yarn, and to discharge the associated airflow around the yarn from between the spinning hole groups before the melt-spun yarn enters the tubular heating device. Is melt-spun from a spinneret in which the spinning hole group is divided into 3 to 8 groups. When the spinneret is divided into less than three groups, the associated airflow around the yarn cannot be sufficiently discharged before entering the tubular heating device, so the associated airflow flows into the tubular heating device, and fineness unevenness occurs, The yarn will have poor yarn quality performance. Also,
If the number of splits exceeds eight groups, the pitch between the spinning holes becomes narrower, the yarns are more likely to adhere to each other during spinning, the fineness unevenness is generated, and the yarn quality is likely to be deteriorated.
Further, it becomes difficult to provide a large number of spinning holes, which causes a decrease in operability.

Next, after the melt-spun yarn is cooled to a temperature below the glass transition point, the yarn is introduced into the tubular heating device 4. In the present invention, the yarn is introduced into the tubular heating device 4. In order to control the inflow of the accompanying airflow, it is necessary to detachably install a throttle guide 5 having a diameter of 5 to 15 mm at the inlet of the tubular heating device 4, and to provide an aspirator 6 below the throttle guide 5 for threading. There is.

If the diameter of the squeezing guide 5 is less than 5 mm, even if the aspirator 6 is used, the squeezing port is too narrow, and the threading operation becomes difficult. When the diameter of the throttle guide 5 exceeds 15 mm, the diameter of the throttle guide 5 becomes large, and the accompanying airflow flows into the tubular heating device 4 to lower the temperature, and the turbulence of the airflow and the temperature drop to the yarn. The heat efficiency of No. 1 becomes poor, the yarn quality of the obtained yarn deteriorates, and fineness unevenness occurs.

FIG. 2 is an enlarged end view showing an embodiment of the vicinity of the inlet of the tubular heating device of the present invention. The aperture guide 5 is attached to the upper portion of the guide attachment portion 15 and is provided below the aperture guide 5. The aspirator 6 for threading is provided with an air supply pipe 16.

In order to easily change the diameter of the drawing guide 5 within a range of 5 to 15 mm depending on the type and fineness of the yarn to be spun, the drawing guide 5 for focusing the yarn is installed at the entrance of the tubular heating device. It must be detachable. The diameter of the aperture guide 5 can be changed, for example, by attaching the aperture guide 5 of each aperture to the tubular heating device 4 via the guide attachment portion 15, as shown in FIG. 2, and can be easily performed at low cost. it can.

Further, since the aspirator 6 installed below the yarn can easily suck the yarn into the tubular heating device 4 and easily thread the yarn, the operability can be improved and further When the threading is completed, the air in the aspirator 6 is stopped, so that the manufacturing cost can be reduced.

Further, the internal temperature of the tubular heating device is 150 to
Must be 250 ° C. If the temperature is lower than 150 ° C, the heat treatment of the yarn becomes insufficient, and the yarn quality performance of the obtained yarn is deteriorated. Further, when the temperature exceeds 250 ° C, the melting point of the polyester becomes close to the melting point of the polyester, so that fusion of the yarn occurs in the tubular heating device
Operability deteriorates. Further, the length of the tubular heating device is not particularly limited, but it is preferable to appropriately select it in the range of 1 to 3 m depending on the type of yarn to be spun.

Further, the drawing guide 5 provided at the inlet of the tubular heating device is preferably a ceramic drawing guide having a yarn contacting portion with a roughness of 2.0 s or less and diamond-polished, and more preferably, the yarn contacting By setting the roughness of the part to 1.5 s or less, this can prevent the yarn from being damaged by contact with the guide, preventing the generation of fluff in the obtained yarn, and improving the yarn quality and uniformity. The property can be further improved. In particular, when spinning a yarn having a single yarn fineness of 1.0 d or less, it is preferable to use a squeezing guide having a small roughness at the yarn contacting portion in order to prevent the occurrence of fluff and to manufacture with good operability. The roughness of the yarn contacting portion was measured by a measuring method of JIS B0651 using a surface roughness meter (model SE40D) manufactured by Kosaka Laboratory.

In FIG. 1, a heat treatment device 10 is provided between the first roller 8 and the second roller 11, and an entanglement treatment device 9 is provided between the second roller 11 and the winding device 12. In the invention, the heat treatment device 10 and the entanglement treatment device 9 do not necessarily have to be provided, and may be appropriately provided depending on the type of yarn to be spun.

The polyester in the present invention contains polyethylene terephthalate as a main constituent component, but may be a mixture or copolymer of a third component or a matting agent as long as it does not substantially change the properties. It may contain a small amount of a colorant, a stabilizer, an antistatic agent, or the like.

The present invention is also a method particularly suitable for the production of polyester filament yarn for clothing, wherein the polymer has a relative viscosity (equal weight mixture of phenol and ethane tetrachloride as a solvent, concentration of 0.5 g / dl, temperature (Measured at 25 ° C) is preferably about 1.30 to 1.45. According to the present invention, for example, a fiber having a single yarn fineness of 0.5 to 4.0 d, a strength of 4.5 g / d or more, an elongation of 40% or less, and a fineness unevenness (U%) of less than 1.0% can be produced, which is suitable for clothing. it can.

[0022]

According to the high speed spinning method of the present invention, the number of spinning hole groups is 3
By melt-spinning from the spinneret divided into more than one group, the effect of cooling the yarn is improved, and by the time the yarn enters the tubular heating device, the associated airflow around the yarn is generated between the spinning hole groups. Can be discharged. Next, after the spun yarn is once cooled to a temperature equal to or lower than the glass transition point, a squeezing guide having a diameter of 5 to 15 mm is provided at the inlet of a cylindrical heating device installed below the spinneret, Since the entrained airflow can be controlled well, it is possible to efficiently heat-treat at a uniform temperature in the apparatus, and to obtain a polyester fiber having no fineness and high yarn quality. Further, since the aspirator for threading is provided below the guide, threading can be performed easily, and further, since the throttle guide is detachably provided at the entrance of the tubular heating device, spinning is performed. The diameter of the squeezing guide can be easily changed according to the type and fineness of the yarn, and the associated airflow can be easily controlled at low cost.

[0023]

EXAMPLES Next, the present invention will be specifically described by way of examples. The characteristic values in the present invention were measured as follows. (a) Strength and elongation Using Autograph DSS-500 manufactured by Shimadzu Corporation, sample length 30c
m, and the pulling speed was 30 cm / min. (B) Fineness Unevenness A half-inert test was performed using a Wooster yarn unevenness measuring device manufactured by Zellvega. (C) Shrinkage rate of boiling water A sample was made into a loop of 50 cm, an initial load of 1/30 g / d was applied to obtain a length A, and then the length was freed and immersed in boiling water for 15 minutes, then naturally dried, and again 1 / The length B was obtained by applying a load of 30 g / d, and calculated by the following formula. Shrinkage rate of boiling water (%) = [(AB) / A] × 100 (d) Number of fluffs Toray Engineering's fluff counter (model DF10
4) was measured at a yarn speed of 1000 m / min, and the number of fluffs per 10 ⁶ m was used.

Example 1 According to the process chart shown in FIG. 1, first, polyethylene terephthalate having a relative viscosity of 1.38 was melted at a melting temperature of 295 ° C. and a discharge rate of 1.15 g / min from a spinneret with four holes having a hole diameter of 0.25 mm and 36 holes. ,
Melt spinning was performed at a take-up speed of 5000 m / min. Pass the spun yarn through a heating cylinder, blow cooling air with a cooling device to once cool it to a temperature below the glass transition point, and then 1.5 from the spinneret.
Heat treatment was carried out by running in a 1.3 m cylindrical heating device provided at a position below m. At the entrance of the cylindrical heating device, the diameter is 10m
A ceramic draw guide with a diameter of m is provided, and an aspirator for threading is provided below the draw guide. The roughness of the yarn contact portion of the draw guide is 0.4 s, and the internal atmosphere temperature of the device is 152 ° C. did. The oil agent is applied to the yarn running in the tubular heating device by the oil agent applying device, and is taken up by the first roller,
Then, it is heat-treated at a temperature of 400 ° C. with a heat treatment device using superheated steam with a relaxation rate of 1.0%, and is entangled by a entanglement imparting device through a second roller, and then wound by a winding device, and then 75d.
A filament yarn of / 36f was obtained. The ambient temperature inside the tubular heating device is 15 cm above the lower part of the tubular heating device and about 5 mm away from the running yarn. A CA sensor with a diameter of 0.5 mm (a chromel-alumel thermoelectric measuring range of 0 to 350 ° C). Pair). Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

Examples 2 and 3 The procedure of Example 1 was repeated, except that the spinning speed (Example 3 only) and the ambient temperature inside the tubular heating device were changed as shown in Table 1. Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

Examples 4 and 5 The same as Example 1 except that the spinning speed (only in Example 5) and the ambient temperature inside the tubular heating device were changed as shown in Table 1 using a 2.6-m tubular heating device. Went to. Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

Example 6 The same procedure as in Example 1 was carried out except that the squeezing guide having a roughness of the yarn contact portion of 3.0 s was used and the atmospheric temperature inside the tubular heating device was changed as shown in Table 1. Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

Comparative Examples 1 to 4 Examples except that the spinning speed (Comparative Example 2 only), the diameter of the squeezing guide (Comparative Examples 3 and 4 only), and the ambient temperature inside the tubular heating device were changed as shown in Table 1. The same procedure as 1 was performed. Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

Comparative Example 5 The same procedure as in Example 1 was carried out except that the spinneret was a spinneret in which the groups of spinning holes were not divided, and the atmosphere temperature inside the tubular heating device was changed as shown in Table 1. Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

Comparative Example 6 The procedure of Example 1 was repeated, except that the inlet of the tubular heating device was opened without providing a throttle guide, and the internal atmospheric temperature of the tubular heating device was changed as shown in Table 1. Table 1 shows the strength, elongation, boiling water shrinkage rate, fineness irregularity, and number of fluffs of the obtained yarn.

[0031]

[Table 1]

As is clear from Table 1, in Examples 1 to 6, the heat treatment could be carried out uniformly and efficiently in the tubular heating device, and the yarn quality of the obtained yarn was excellent. On the other hand, in Comparative Example 1, since the internal temperature of the tubular heating device was too high, the yarn was fused inside the tubular heating device, and the yarn could not be stably obtained. In Comparative Example 2, the stress applied to the yarn was insufficient due to the low spinning speed, and thus only the yarn having low strength and high elongation and large fineness unevenness was obtained. In Comparative Example 3, threading was difficult because the aperture guide was too small. In Comparative Example 4, since the diameter of the drawing guide was large, even if the temperature inside the tubular heating device was raised, the ambient temperature inside the tubular heating device fell due to the inflow of the accompanying air flow, and the yarn was not sufficiently heat treated. Therefore, the obtained yarn became a low-strength, high-elongation yarn, and became a yarn with large fineness unevenness due to turbulence of the air flow. In Comparative Example 5, since the spinning hole group of the spinneret was not divided, the accompanying airflow could not be sufficiently removed, and the ambient temperature inside the tubular heating device was low, so the yarn was sufficiently heat treated. However, only yarns with large fineness unevenness were obtained. In Comparative Example 6, since the throttle guide was not provided at the inlet of the tubular heating device, the accompanying airflow flowed in, and as in Comparative Example 4, the yarn quality was low and only yarns with large fineness unevenness were obtained.

[0033]

EFFECTS OF THE INVENTION According to the present invention, the inflow of the accompanying air current into the tubular heating device can be controlled, and the yarn can be uniformly and efficiently heat-treated in the device. High-performance polyester fibers can be produced at high speed with good operability. Furthermore, since the aperture of the throttle guide can be easily changed, the associated airflow can be easily controlled at low cost.

[Brief description of drawings]

FIG. 1 is a schematic process drawing showing an embodiment of a high-speed spinning method of the present invention.

FIG. 2 is an enlarged end view of the vicinity of the inlet of the tubular heating device of FIG.

FIG. 3 is a plan view showing an embodiment of a spinneret used in the high-speed spinning method of the present invention.

[Explanation of symbols]

 1 Spinneret 2 Heating Cylinder 3 Cooling Device 4 Cylindrical Heating Device 5 Squeezing Guide 6 Aspirator 7 Lubricant Applying Device 8 1st Roller 9 Entanglement Applying Device 10 Heat Treatment Device 11 2nd Roller 12 Winding Device 15 Guide Attachment 16 Air Supply Pipe

Claims (1)

[Claims] 1. A yarn melt-spun from a spinneret is once cooled to a temperature below a glass transition point, then run in a tubular heating device to be heat treated, and then an oil agent is applied thereto, and a speed of 4000 m / min or more is applied. In the high-speed spinning method, the spinning hole group is melt-spun from a spinneret divided into three or more groups, and a drawing guide having a diameter of 5 to 15 mm is detachably provided at the inlet of the tubular heating device, and below the guide. A high-speed spinning method for polyester fibers, characterized in that an aspirator for threading is provided, and the internal temperature of the tubular heating device is set to 150 to 250 ° C.