JPH0617312A - Direct spinning and drawing of polyester fiber - Google Patents

Abstract

PURPOSE:To provide a direct spinning and drawing process capable of producing a polyester fiber having excellent uniformity and small dyeing unevenness in high workability. CONSTITUTION:Melt-spun polyester filaments are cooled, coated with an aqueous lubricant, taken up with a hot take-up roller 6 and continuously drawn between the hot take-up roller 6 and a hot drawing roller 8. In the above process, the filament is treated with a pressurized hot gas flow of 50-150 deg.C and 0.3-3.0kg/cm<2> pressure at the upstream side of the hot take-up roller to decrease the water- content of the filament to <=3.0wt.% and apply entanglements to the filament at a rate of >=0.5 entanglements per 1m.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct spinning / drawing method capable of producing polyester fibers having excellent uniformity and particularly less dyed spots with good operability.

[0002]

2. Description of the Related Art As a method for producing polyester fibers, a direct spinning drawing method is widely adopted. Then, in the case of producing polyester fiber for clothing, an aqueous oil agent is applied to the melt spun yarn, and the yarn is preheated to a glass transition point or higher by a heating take-up roller and drawn, and drawn between the take-up roller and the drawing roller. The method is generally used. In this case, when the yarn is preheated to a temperature above the glass transition point, the amount of heat received by the yarn is different between single yarns due to the unevenness of adhesion of the oily agent, and single yarn breakage, roller winding, stretch unevenness, etc. are likely to occur and uniform yarns are obtained. There was a problem that the article could not be obtained.

As a method for solving such a problem, a yarn to which an aqueous oil agent is applied is treated with a pressurized fluid upstream of a take-up roller so that the yarn is entangled and the water is scattered to reduce the amount of attached water. How to reduce it (Japanese Patent Publication No.
No. 56-9976 and Japanese Patent Laid-Open No. 59-13031). However, with the conventional method, it is not possible to obtain a yarn that is sufficiently uniform and has less uneven dyeing, probably because the water is not evenly scattered.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a method for direct spinning and drawing a polyester fiber which has excellent uniformity and is capable of producing a polyester fiber having less uneven dyeing with good operability.

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that this object can be achieved by optimizing the treatment conditions by a pressurized gas flow. Heading, arrived at the present invention.

That is, according to the present invention, the melt spun polyester fiber yarn is cooled, an aqueous oil agent is applied thereto, and then taken up by a heating take-up roller, and continuously drawn between the heating take-up roller and the heating drawing roller. In the direct spinning and drawing method, the yarn is heated to a temperature of 50-
Treated with a heated and pressurized gas flow at 150 ° C and a pressure of 0.3 to 3.0 kg / cm ^{2 to} reduce the moisture content of the yarn to 3.0% by weight or less
The gist is a direct spinning and drawing method of polyester fibers, which is characterized by imparting entanglement of 0.5 co / m or more.

The present invention will be described in detail below. In the present invention, first, a polyester is melt-spun by a conventional method, and an aqueous oil agent is applied to the spun yarn. A normal water-based oil is used as the oil, but the water content is 80-85% because it can be applied relatively uniformly and has good operability.
Something is preferable.

Then, the yarn to which the oil agent is applied is heated at a temperature of 50 to
Treated with a heated and pressurized gas flow at 150 ° C and a pressure of 0.3 to 3.0 kg / cm ^{2 to} reduce the moisture content of the yarn to 3.0% by weight or less
Entangle 0.5 cores / m or more. Temperature of gas flow is 50 ℃
If it is less than this, uniform water removal cannot be carried out, the stretching becomes uneven, and unevenness in fineness occurs, which is not preferable. On the other hand, if the temperature of the gas flow exceeds 150 ° C., the yarn is crystallized in a low orientation state, so uniform drawing cannot be performed, and single yarn breakage and uneven dyeing occur, which is not preferable. Also, the gas flow pressure is 0.3 kg / c
If it is less than m ² , sufficient entanglement cannot be imparted, the yarn converging property becomes small, the yarn opens and shakes on the heating roller, and roller winding and yarn breakage frequently occur. On the other hand, when the pressure of the gas flow exceeds 3.0 kg / cm ² , the elongation of the unstretched yarn partially occurs due to the interaction between the fluid temperature and the fluid velocity, resulting in uneven stretching, and loops and fluff appear. Is not preferable.

The water content and the degree of entanglement of the yarn are adjusted by adjusting the temperature and pressure of the gas flow within the above range. If the moisture content of the yarn exceeds 3.0% by weight, the uneven adhesion is not eliminated and uniform stretching cannot be performed, and uneven dyeing occurs, which is not preferable. In addition, the degree of entanglement of yarn is 0.5 k / m
If it is less than the above range, the yarns are opened on the heating take-up roller, or the yarns come into contact with each other, which often causes yarn breakage, which is not preferable.

It is preferable to use air as the heating and pressurizing gas from the viewpoint of operation cost and safety, and as the heating and pressurizing gas flow treatment device, an entanglement treatment nozzle can be used in view of downsizing of the device. It is preferably used.

FIG. 1 is a schematic process diagram showing one embodiment of the method of the present invention, and shows an example of simultaneously producing two yarns. The yarn 2 discharged from the spinneret 1 is cooled by a cooling device 3 and solidified, and then an aqueous oil agent is applied while being focused by an oil agent applying device 4, and then treated by a heating / pressurizing gas flow processor 5. After that, it is taken up by the heating take-up roller 6. The heated gas flow migrates the single yarn forming the yarn, lowers the moisture content of the yarn, and imparts entanglement to the yarn. Subsequently, the yarn 2 is wound around the heating take-up roller 6 and the separation roller 7 several times, heated to a temperature necessary for stretching, and then guided to the heating stretching roller 8 and the separation roller 9 and wound several times. The film is drawn between the heating take-up roller 6 and the heating drawing roller 8 at a predetermined drawing ratio.
The stretched yarn then passes through guides 10 and 11 and is wound into a package 13 by a winding roller 12.
If necessary, an entanglement treatment device may be provided between the heating and stretching roller 8 and the take-up roller 12 to further provide entanglement.

[0012]

According to the present invention, the reason why the evenness of the yarn is improved and the uneven dyeing is eliminated is not clear. However, the spun yarn is preheated by a heated and pressurized gas flow, and the strain of the spun yarn is The moisture content of the spun yarn is low, and the heat amount received from the heating roller at the time of drawing is made uniform among the single yarns of the yarn by being made uniform, and the drawing is also made uniform. Is recognized. Further, according to the present invention, since a proper entanglement is imparted to the yarn before stretching, the yarn does not open and sway on the heating roller, and the roller winding and the yarn breakage do not occur, and the operation is performed. The property becomes good.

[0013]

EXAMPLES Next, the present invention will be specifically described with reference to examples. The measurement and evaluation of characteristic values and the like in the examples were performed as follows. (a) Intrinsic viscosity [η] It was measured at a temperature of 20.0 ° C using an equal weight mixture of phenol and ethane tetrachloride as a solvent. (b) Adhesion Moisture Content When the yarn was produced by the device shown in FIG. 1, the rollers 6 and 8 were not heated, and both rollers were wound at the same speed, sampled, and measured according to JIS L 1073. (c) Degree of entanglement Sampling was carried out in the same manner as the sample for measuring the adhered water content, a load of 0.05 g / d was applied to the yarn, and the yarn was single yarn without damage to the single yarn in the sample of 1 m in length. The number of points that were not separated from each other was measured. (Indicated as an average value for 10 samples.) (D) Yarn break The number of yarn breaks per 100 hours of spinning time was counted. (e) Loops and fluff The loops and fluffs of 6 kg rolled cheese were counted by visual judgment, and graded in the following three stages. ◯: Occurrence of loops and fluffs is 0 to 1 △: Occurrence of loops and fluffs is 2 to 4 ×: Occurrence of loops and fluffs is 5 or more (f) Dye spots 1 compared with a standard sample by visual judgment A grade of ~ 5 was applied. (1st grade shows the most stains, and 5th grade shows the least stains.)

The oil agents used in the examples and comparative examples are
A composition comprising 30% by weight of mineral oil, 45% by weight of fatty acid ester, 10% by weight of anionic surfactant, 10% by weight of nonionic surfactant and 5% by weight of a modifier in a water emulsion having a concentration of 16% by weight, 1.3% by weight adhered to the yarn
(Oil content was 0.8% by weight, water content was 0.5% by weight).

Example 1 Polyethylene terephthalate of [η] 0.68 was melted at 290 ° C., discharged from a spinneret having 36 nozzles having a hole diameter of 0.25 mm, and air at room temperature was blown to cool and solidify the spun yarn. The oil solution was applied to the sample by a measuring oiling device. Subsequently, it was treated with a heated pressurized air stream at a temperature of 120 ° C and a pressure of 1.5 kg / cm ² , and then it was drawn by a take-up roller heated to 90 ° C at a speed of 1400 m / min, and heated to 130 ° C with a heated take-up roller. The film was stretched 3.0 times with the stretching roller rotating at a speed of 4200 m / min, heat-treated and wound.
The obtained drawn yarn has a fineness of 73.5d and a strength of 4.95g /
d, elongation 34.7%, boiling water shrinkage 7.2%. The drawn yarn obtained did not have loops or fluff, and when this was knitted by knitting and dyed to determine the dye spots, there was no dye spots.

Examples 2 to 7 The procedure of Example 1 was repeated, except that the temperature and pressure of the heated and pressurized air stream were changed to change the yarn moisture content and the degree of entanglement. The temperature of the heating and taking-off roller was changed in advance in the range of 50 to 150 ° C. along with the change in the heating and pressurizing airflow treatment condition, and the temperature was measured with a fluff counter for 30 minutes to select the temperature condition with the least fluff generation. The drawn yarns obtained were all fineness: 73 ± 2.2 d, strength: 4.60 g / d or more, elongation:
33 ± 3%, boiling water shrinkage: 7 ± 1.0%.

Comparative Examples 1 to 6 Comparative Examples 1 to 6 were carried out in the same manner as in Examples 1 to 7 except that the temperature and pressure of the pressurized air flow were changed as shown in Table 1. The results of the above Examples and Comparative Examples are shown in Table 1.

[0018]

[Table 1]

[0019]

Industrial Applicability According to the present invention, it is possible to produce a polyester fiber having excellent uniformity and less uneven dyeing with good operability.

[Brief description of drawings]

FIG. 1 is a schematic process diagram showing an embodiment of the present invention.

[Explanation of symbols] 1 Spinneret 2 Thread 3 Cooling device 4 Oil agent applying device 5 Heated pressurized gas flow processor 6 Heated take-up roller 8 Heated drawing roller

Claims (1)

[Claims] 1. A direct spinning / drawing method in which a melt-spun polyester fiber yarn is cooled, an aqueous oil agent is applied thereto, and then taken up by a heating take-up roller and continuously drawn between a heating take-up roller and a heating draw roller. In the upstream of the heating take-up roller, the yarn temperature is 50 to 150 ° C and the pressure is 0.3 to 3.
Treated with a heated pressurized gas flow of 0 kg / cm ² , and the yarn moisture content is 3.0.
A method for direct spinning and drawing polyester fibers, which comprises not more than 10% by weight and imparts entanglement of 0.5 k / m or more to the yarn.