JP4009370B2

JP4009370B2 - Production method of polyester fiber

Info

Publication number: JP4009370B2
Application number: JP23684098A
Authority: JP
Inventors: 和典橋本; 幸治角本
Original assignee: Unitika Ltd
Current assignee: Unitika Ltd
Priority date: 1998-08-24
Filing date: 1998-08-24
Publication date: 2007-11-14
Anticipated expiration: 2018-08-24
Also published as: JP2000073230A

Description

【０００１】
【発明の属する技術分野】
本発明は、ポリトリメチレンテレフタレート（ＰＴＴ）を主体とするポリエステル繊維を、筒状加熱装置を用いて製造する方法に関するものである。
【０００２】
【従来の技術】
ＰＴＴは、溶融成形性に優れたポリエステルの一種であり、溶融紡糸法により得られる繊維は、弾性に優れ、柔軟であり、広範な用途に適用可能である。ＰＴＴは、ポリエチレンテレフタレートを主とする汎用のポリエステル繊維と同様に、溶融紡糸した糸を熱延伸することで実用的な物性の繊維とすることができる。
【０００３】
しかしながら、ＰＴＴは、延伸熱処理時に断糸しやすいため、安定に採取するには熱処理温度を高くすることができない。したがって、熱収縮率を低くすることが困難であり、布帛としたときには寸法安定性の劣ったものとなりやすい。また、捲き取り直後の収縮が大きいため、パッケージに捲き取った際の捲き姿が不良となりやすく、捲き量に制約があるなど種々の問題点があった。
【０００４】
これらの問題を解決するために、特開昭５２−８１２３号公報では、紡糸直後の糸条を冷却することなく、かつ高配向の糸条となるようにして引き取り、その糸条を延伸、熱処理する方法が提案されており、特開昭５２−８１２４号公報では、延伸熱処理を２段以上で行う方法が提案されている。また、特開昭５８−１０４２１６号公報では、引取速度を２０００ｍ／分以上として高配向の糸条を得、この高配向の未延伸糸を熱延伸する方法が提案されている。
【０００５】
これらの方法によれば、ある程度の延伸操業性は改善されたが、捲き取り時の問題点は解消されず、また、いずれも、紡糸工程と延伸工程を別工程で行い、低速で熱延伸した例しか示されておらず、特に、紡糸と延伸を一工程で行う高速延伸時においては、延伸及び捲き取り時の問題を解消することはできなかった。
【０００６】
さらに、特公平５−４５６８３号公報では、引取速度が９０００ｍ／分以上の超高速紡糸による方法が提案されているが、この方法では単糸切れ等の発生が多く、操業的安定性に欠けると同時に、引取速度のみで糸条の物性を制御するため、物性の制御が困難であり、用途に応じた物性を有する繊維を得ることができないという問題があった。
他にも、ＰＴＴを主体とした繊維の製造方法に関する提案が種々行われているが、十分に満足できるような物性を有するＰＴＴ繊維を、単糸切れ等の発生がなく、安定して生産することができる製造方法は未だ確立されていない。
【０００７】
【発明が解決しようとする課題】
本発明は上記のような問題点を解決するものであって、ＰＴＴを主体とする柔軟性に優れたポリエステル繊維を、高速一工程法によって、延伸、熱処理時の断糸がなく、良好な捲姿のパッケージに巻き取ることができ、安定して生産することができるポリエステル繊維の製造法を提供することを技術的な課題とするものである。
【０００８】
【課題を解決するための手段】
本発明者らは、上記の課題を解決するために検討した結果、本発明に到達した。
すなわち、本発明は、ポリトリメチレンテレフタレートを主体とするポリエステルを、紡糸口金より溶融紡出し、紡糸した糸条を一旦冷却固化した後、内部雰囲気温度が１２０〜２２０℃の筒状加熱装置を通過させて熱処理し、再び冷却した後、３０００ｍ／分以上の引取速度で糸条を引き取り、弛緩率４〜１２％で弛緩熱処理を施し、捲き取ることを特徴とするポリエステル繊維の製造法を要旨とするものである。
【０００９】
【発明の実施の形態】
以下、本発明を図面を用いて詳細に説明する。
図１は、本発明の一実施態様を示す概略工程図である。まず、紡糸口金１からポリエステル糸条Ｙを溶融紡糸し、冷却風吹付装置２によって糸条を冷却固化した後、筒状加熱装置３の中を通過させて熱処理する。加熱装置を通過した糸条を自然冷却後、油剤付与装置４により油剤付与と同時に集束し、第１ローラ（引取ローラ）５により引き取り、第２ローラ６を介して弛緩熱処理を施し、捲取装置７で捲き取る。
【００１０】
本発明においては、筒状加熱装置を用い、糸条が筒状加熱装置３内を空気抵抗を受けながら高速で通過することにより、集束された時点で低速延伸糸と同様に配向と結晶化が促進されており、しかもこの間、糸条に接触するものはないため、断糸の頻度は極めて低く、非常に安定して加熱延伸を施すことができる。
【００１１】
筒状加熱装置３の内部雰囲気温度は１２０〜２２０℃の範囲に設定することが必要である。１２０℃未満では加熱効果が乏しく、２２０℃を超えると、糸条が壁面に接触したときに融着が生じる。
【００１２】
また、筒状加熱装置３の加熱装置の有効加熱長は、５０〜２００ｃｍとすることが好ましい。５０ｃｍより短いと、加熱延伸が不十分となりやすく、２００ｃｍより長いと、口金から集束位置までの距離が長くなるため、糸揺れに起因した糸斑が発生しやすく、好ましくない。
【００１３】
次に、筒状加熱装置３で加熱延伸した糸条を、自然冷却した後、引取速度３０００ｍ／分以上、さらに好ましくは、３０００〜５５００ｍ／分の引取速度で引き取る。図１においては、引取速度は第１ローラ５の速度である。引取速度が３０００ｍ／分より低いと、加熱装置内で延伸に必要な空気抵抗が十分に加わらず、延伸が不十分となる。一方、５５００ｍ／分より高いと、加熱装置内の通過時間が短くなり、加熱効果が不十分となる。
【００１４】
引き取った糸条は、そのまま捲き取っても実用的な物性を有する繊維が得られるが、多量の捲量をパッケージに安定に捲き取るために、引き続き、弛緩率４〜１２％で弛緩熱処理を施す。図１においては、第２ローラ６と捲取装置７との間で弛緩熱処理を施す。この際、糸条の加熱方法は、第２ローラ６を表面温度が１２０〜１８０℃の加熱ローラとする方法や、第２ローラ６と捲取装置７との間に加熱蒸気等の加熱気体による熱処理装置を設置し、糸条温度が１００℃以上になるようにすることが好ましい。
【００１５】
ＰＴＴからなる糸条は、通常、捲き取り直後の収縮が大きいため、多量に捲き取るとパッケージの捲き姿が悪くなり、極端な場合、捲取装置からの脱着が困難になる。このため、捲取直前に弛緩熱処理を行うことが必要であるが、通常の加熱ローラによる延伸法では、弛緩熱処理に必要な熱量を十分に与えるべく、上記のような温度で熱処理すると、加熱ローラ上で糸揺れが生じて単糸切れ等が発生し、操業性が悪かった。本発明では、筒状加熱装置で加熱延伸処理を行い、糸条を引き取った時点で十分に配向と結晶化が促進されているため、上記のような温度で加熱処理を施しても安定に糸条を通過させることが可能である。
【００１６】
弛緩熱処理時の弛緩率は４〜１２％とすることが必要である。弛緩率が４％より低いと弛緩熱処理が不十分であるために捲姿が不良となり、１２％より高いと第２ローラ６と捲取装置７との間の張力が低くなりすぎ、安定して捲き取ることができなくなる。
【００１７】
本発明で使用するポリエステルは、ＰＴＴを主体とするものであるが、ポリエステル本来の性質を損なわない程度において、第３成分が混合あるいは共重合されたもの、あるいは艶消剤、着色剤、安定剤、制電剤等を含んでいるものでもよい。
【００１８】
また、重合度は繊維形成性を損なわない範囲であれば、特に限定されるものではないが、本発明は、特に、衣料用のマルチフィラメントの製造に適した方法であり、相対粘度（フェノールと四塩化エタンとの当重量混合物を溶媒とし、濃度０．５ｇ／ｄｌ、温度２５℃で測定した）が１．４０〜１．７０程度のものが好ましい。
【００１９】
本発明の方法によれば、種々の銘柄の糸条を得ることが可能であるが、特に、単糸繊度が０．３〜６．０ｄ、さらには０．５〜５．０ｄ、フィラメント数が３〜１００本の繊維を得るのに適している。
そして、本発明によれば、強度が３．０〜５．０ｇ／ｄ、伸度が２５〜５０％、初期ヤング率が２０〜３０ｇ／ｄ程度のポリエステル繊維を製造することが可能であり、低ヤング率であるため、布帛にすると、柔軟性に富んだ布帛を得ることができる。
【００２０】
【実施例】
以下、本発明を実施例により具体的に説明する。なお、実施例中における強伸度及び初期ヤング率の測定は次のとおりに行った。
(a) 強伸度
島津製作所製オートグラフＳ−１００を用い、JIS L 1013に準じて測定した。
(b) 初期ヤング率
強伸度測定時に得られた荷重−伸張曲線の初期の傾きから求めた。
【００２１】
実施例１
相対粘度が１．６０のＰＴＴチップをエクストルーダー型溶融紡糸機に供給し、直径０．２５ｍｍの紡糸孔を３６個有する２重円配列の紡糸口金から紡糸温度２７０℃で紡出した。紡糸した糸条に口金面より５ｃｍ下方に配した長さ２０ｃｍの環状冷却装置より風温１５℃、風速４８ｍ／分の冷却風を吹き付けて冷却、固化した後、口金面より１５０ｃｍ下方に、有効加熱長が１００ｃｍで内部雰囲気温度が１５０℃の筒状加熱装置を通過させて、加熱延伸を行った。続いて、加熱装置出口より４０ｃｍ下方に油剤付与装置を設け、油剤を付与すると同時に糸条を集束した後、３５００ｍ／分の第１ローラ（室温）で引き取り、次に、１５０℃、表面速度３５１０ｍ／分の第２ローラを介して、弛緩率５．７％として弛緩熱処理して捲取速度３３１０ｍ／分の捲取装置で５ｋｇ巻きのパッケージに捲き取り、７５ｄ／３６ｆのポリエステル繊維を得た。
得られた繊維の強度、伸度、初期ヤング率を測定した値を表１に示す。
【００２２】
実施例２〜３、比較例１〜５
筒状加熱装置の内部雰囲気温度、第１ローラの速度（引取速度）、第２ローラの速度、弛緩率、捲取速度を表１に示すように種々変更した以外は、実施例１と同様に行った。
【００２３】
比較例６
筒状加熱装置を設けることなく、第１ローラの温度を７０℃とし、速度を２２００ｍ／分として第１ローラと第２ローラの間で延伸、熱処理を施し、このとき、第２ローラの温度１３０℃、速度４３２０ｍ／分とし、さらに、第２ローラと捲取装置との間で弛緩率７．４％で弛緩熱処理して巻き取った以外は、実施例１と同様に行った。
得られた繊維の強度、伸度、初期ヤング率を測定した値を表１に示す。
【００２４】
【表１】

【００２５】
表１から明らかなように、実施例１〜４では、延伸熱処理時の糸切れが少なく、十分な捲き量を良好な捲き姿のパッケージに捲き取ることができ、得られた繊維は、いずれも十分な強伸度等の物性を有するものであった。
一方、比較例１は、筒状加熱装置の温度が低すぎたため、得られた繊維は伸度が大きく、強度も低かった。比較例２は、筒状加熱装置の温度が高すぎたため、糸条が融着し、採取できなかった。また、比較例３は、引取速度が低すぎたため、得られた繊維は強度が低いものであった。比較例４は、弛緩率が低すぎたため、捲き取り直後の繊維の収縮が大きく、パッケージの捲姿が悪くなり、捲取装置からの脱着が困難であった。比較例５は、弛緩率が高すぎたため、第２ローラと捲取装置の間で糸条がたるみ断糸し、捲き取ることができなかった。比較例６は、筒状加熱装置を使用せず、通常のローラを用いた延伸法であったため、第２ローラ上での単糸の切断が多発した。
【００２６】
【発明の効果】
本発明によれば、ＰＴＴを主体とする柔軟性に優れたポリエステル繊維を、高速一工程法によって、延伸、熱処理時の断糸の発生もなく、十分な捲き量を良好な捲き姿のパッケージに巻き取ることができ、生産性よく、工業的に安定に製造することが可能となる。
【図面の簡単な説明】
【図１】本発明の製造法の一実施態様を示す概略工程図である。
【符号の説明】
Ｙ糸条
１紡糸口金
２冷却風吹付装置
３筒状加熱装置
４油剤付与装置
５第１ローラ（引取ローラ）
６第２ローラ
７捲取装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polyester fiber mainly composed of polytrimethylene terephthalate (PTT) using a cylindrical heating device.
[0002]
[Prior art]
PTT is a kind of polyester excellent in melt moldability, and fibers obtained by melt spinning are excellent in elasticity and flexible, and can be applied to a wide range of uses. PTT can be made into a fiber having practical physical properties by hot-drawing a melt-spun yarn in the same manner as a general-purpose polyester fiber mainly composed of polyethylene terephthalate.
[0003]
However, since PTT tends to break during the drawing heat treatment, it is not possible to increase the heat treatment temperature for stable collection. Therefore, it is difficult to reduce the heat shrinkage rate, and when the fabric is used, it tends to be inferior in dimensional stability. In addition, since the shrinkage immediately after scraping is large, there is a variety of problems such as the cracking appearance when the package is scraped off, and the amount of scraping is limited.
[0004]
In order to solve these problems, in Japanese Patent Laid-Open No. 52-8123, the yarn immediately after spinning is taken out without being cooled and becomes a highly oriented yarn, and the yarn is drawn and heat treated. Japanese Laid-Open Patent Publication No. 52-8124 proposes a method of performing stretching heat treatment in two or more stages. Japanese Patent Laid-Open No. 58-104216 proposes a method in which a highly oriented yarn is obtained at a take-up speed of 2000 m / min or more, and this highly oriented undrawn yarn is heat drawn.
[0005]
According to these methods, the stretching operability has been improved to some extent, but the problems at the time of winding are not solved, and in both cases, the spinning process and the stretching process are performed in separate processes, and hot stretching is performed at a low speed. Only examples are shown, and in particular, at the time of high-speed stretching in which spinning and stretching are performed in one step, the problems at the time of stretching and scraping could not be solved.
[0006]
Furthermore, in Japanese Patent Publication No. 5-45683, a method using ultra-high speed spinning with a take-up speed of 9000 m / min or more is proposed. However, in this method, there are many occurrences of single yarn breakage and the operational stability is lacking. At the same time, since the physical properties of the yarn are controlled only by the take-up speed, there is a problem that it is difficult to control the physical properties and it is impossible to obtain fibers having physical properties according to the application.
In addition, various proposals have been made regarding a method for producing fibers mainly composed of PTT, but PTT fibers having sufficiently satisfactory physical properties are stably produced without occurrence of single yarn breakage or the like. The manufacturing method that can be used has not been established yet.
[0007]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems. A polyester fiber excellent in flexibility, mainly composed of PTT, is free from yarn breakage during stretching and heat treatment by a high-speed one-step method. It is a technical problem to provide a method for producing a polyester fiber that can be wound around a package in a form and can be stably produced.
[0008]
[Means for Solving the Problems]
The inventors of the present invention have arrived at the present invention as a result of studies to solve the above problems.
That is, in the present invention, a polyester mainly composed of polytrimethylene terephthalate is melt-spun from a spinneret, the spun yarn is once cooled and solidified, and then passed through a cylindrical heating device having an internal atmospheric temperature of 120 to 220 ° C. The method of producing a polyester fiber is characterized in that after heat treatment and cooling again, the yarn is taken up at a take-up speed of 3000 m / min or more, subjected to relaxation heat treatment at a relaxation rate of 4 to 12%, and then wound up. To do.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic process diagram showing one embodiment of the present invention. First, the polyester yarn Y is melt-spun from the spinneret 1, and the yarn is cooled and solidified by the cooling air blowing device 2. Then, the polyester yarn Y is passed through the cylindrical heating device 3 and heat-treated. The yarn that has passed through the heating device is naturally cooled, then converged simultaneously with the application of the oil agent by the oil agent application device 4, taken up by the first roller (take-off roller) 5, and subjected to a relaxation heat treatment through the second roller 6, and the winding device Scrape at 7.
[0010]
In the present invention, a cylindrical heating device is used, and the yarn passes through the cylindrical heating device 3 at high speed while receiving air resistance. During this period, there is nothing that comes into contact with the yarn, so the frequency of yarn breakage is extremely low, and heat drawing can be performed very stably.
[0011]
It is necessary to set the internal atmospheric temperature of the cylindrical heating device 3 in a range of 120 to 220 ° C. If it is less than 120 ° C, the heating effect is poor, and if it exceeds 220 ° C, fusion occurs when the yarn contacts the wall surface.
[0012]
Moreover, it is preferable that the effective heating length of the heating apparatus of the cylindrical heating apparatus 3 shall be 50-200 cm. When the length is shorter than 50 cm, the heat stretching tends to be insufficient, and when the length is longer than 200 cm, the distance from the die to the converging position becomes long.
[0013]
Next, after the yarn heated and stretched by the cylindrical heating device 3 is naturally cooled, it is taken up at a take-up speed of 3000 m / min or more, more preferably 3000 to 5500 m / min. In FIG. 1, the take-up speed is the speed of the first roller 5. When the take-up speed is lower than 3000 m / min, the air resistance necessary for stretching is not sufficiently applied in the heating device, and stretching becomes insufficient. On the other hand, when it is higher than 5500 m / min, the passage time in the heating device is shortened, and the heating effect becomes insufficient.
[0014]
Even if the drawn yarn is scraped off as it is, fibers having practical physical properties can be obtained, but in order to stably scrape a large amount of kite into the package, a relaxation heat treatment is subsequently applied at a relaxation rate of 4 to 12%. . In FIG. 1, relaxation heat treatment is performed between the second roller 6 and the scraping device 7. At this time, the yarn is heated by a method in which the second roller 6 is a heating roller having a surface temperature of 120 to 180 ° C. or a heating gas such as heating steam between the second roller 6 and the scooping device 7. It is preferable to install a heat treatment apparatus so that the yarn temperature is 100 ° C. or higher.
[0015]
Since a yarn made of PTT usually has a large shrinkage immediately after being scraped off, if it is scraped in a large amount, the appearance of the package becomes worse, and in an extreme case, it is difficult to remove it from the trapping device. For this reason, it is necessary to perform a relaxation heat treatment immediately before cutting, but in the ordinary stretching method using a heating roller, if a heat treatment is performed at the above-described temperature in order to provide a sufficient amount of heat necessary for the relaxation heat treatment, The yarn swayed above, causing breakage of single yarn, etc., and the operability was poor. In the present invention, since the orientation and crystallization are sufficiently promoted at the time when the yarn is drawn by performing the heat drawing treatment with the cylindrical heating device, the yarn can be stably provided even when the heat treatment is performed at the above temperature. It is possible to pass through the strip.
[0016]
The relaxation rate during the relaxation heat treatment needs to be 4 to 12%. If the relaxation rate is lower than 4%, the heat treatment is not sufficient, so that the saddle shape is poor. If the relaxation rate is higher than 12%, the tension between the second roller 6 and the scraping device 7 becomes too low and stable. Can no longer be scraped off.
[0017]
The polyester used in the present invention is mainly composed of PTT, but has a third component mixed or copolymerized to the extent that the original properties of the polyester are not impaired, or a matting agent, colorant, stabilizer. It may also contain an antistatic agent or the like.
[0018]
The degree of polymerization is not particularly limited as long as it does not impair the fiber-forming property, but the present invention is a method particularly suitable for the production of multifilaments for clothing, and the relative viscosity (phenol and A mixture having an equivalent weight mixture with ethane tetrachloride as a solvent and having a concentration of 0.5 g / dl and a temperature of 25 ° C. is preferably about 1.40 to 1.70.
[0019]
According to the method of the present invention, it is possible to obtain yarns of various brands. In particular, the single yarn fineness is 0.3 to 6.0 d, further 0.5 to 5.0 d, and the number of filaments is Suitable for obtaining 3 to 100 fibers.
According to the present invention, it is possible to produce a polyester fiber having a strength of 3.0 to 5.0 g / d, an elongation of 25 to 50%, and an initial Young's modulus of about 20 to 30 g / d. Since it has a low Young's modulus, when it is made into a fabric, a fabric rich in flexibility can be obtained.
[0020]
【Example】
Hereinafter, the present invention will be specifically described by way of examples. In the examples, the strength and initial Young's modulus were measured as follows.
(a) High elongation degree It measured according to JIS L 1013 using autograph S-100 made by Shimadzu Corporation.
(b) The initial Young's modulus was determined from the initial slope of the load-elongation curve obtained at the time of measuring the high elongation.
[0021]
Example 1
A PTT chip having a relative viscosity of 1.60 was supplied to an extruder-type melt spinning machine, and was spun at a spinning temperature of 270 ° C. from a spinneret of a double circular arrangement having 36 spinning holes having a diameter of 0.25 mm. Effectively, after cooling and solidifying the spun yarn by blowing a cooling air with a wind temperature of 15 ° C and a wind speed of 48 m / min from an annular cooling device with a length of 20 cm placed 5 cm below the die surface, and effective 150 cm below the die surface. The film was passed through a cylindrical heating apparatus having a heating length of 100 cm and an internal atmosphere temperature of 150 ° C. to perform heat stretching. Subsequently, an oil agent application device is provided 40 cm below the outlet of the heating device, the oil agent is applied, and at the same time the yarn is focused, and then taken up by the first roller (room temperature) at 3500 m / min, and then at 150 ° C. and a surface speed of 3510 m. A relaxation heat treatment was performed at a relaxation rate of 5.7% through a second roller per minute, and the product was wound up into a 5 kg-wrapped package with a weaving device having a weaving speed of 3310 m / min to obtain a 75 d / 36 f polyester fiber.
Table 1 shows values obtained by measuring the strength, elongation, and initial Young's modulus of the obtained fiber.
[0022]
Examples 2-3 and Comparative Examples 1-5
As in Example 1, except that the internal atmospheric temperature of the cylindrical heating device, the speed of the first roller (take-off speed), the speed of the second roller, the relaxation rate, and the take-up speed were variously changed as shown in Table 1. went.
[0023]
Comparative Example 6
Without providing a cylindrical heating device, the temperature of the first roller is set to 70 ° C., the speed is set to 2200 m / min, and stretching and heat treatment are performed between the first roller and the second roller. The process was carried out in the same manner as in Example 1 except that the film was wound at a temperature of 4320 m / min and further subjected to relaxation heat treatment at a relaxation rate of 7.4% between the second roller and the scraper.
Table 1 shows values obtained by measuring the strength, elongation, and initial Young's modulus of the obtained fiber.
[0024]
[Table 1]

[0025]
As apparent from Table 1, in Examples 1 to 4, the yarn breakage during the stretching heat treatment was small, and a sufficient amount of winding could be wound into a package having a good winding shape. It had physical properties such as sufficient strength and elongation.
On the other hand, in Comparative Example 1, since the temperature of the cylindrical heating device was too low, the obtained fiber had high elongation and low strength. In Comparative Example 2, since the temperature of the cylindrical heating device was too high, the yarn was fused and could not be collected. In Comparative Example 3, since the take-up speed was too low, the obtained fiber had low strength. In Comparative Example 4, since the relaxation rate was too low, the shrinkage of the fiber immediately after winding was large, the package shape deteriorated, and it was difficult to detach from the scraping device. In Comparative Example 5, since the relaxation rate was too high, the yarn slackened between the second roller and the winding device and could not be wound off. Since Comparative Example 6 was a drawing method using a normal roller without using a cylindrical heating device, the single yarn was frequently cut on the second roller.
[0026]
【The invention's effect】
According to the present invention, a polyester fiber excellent in flexibility mainly composed of PTT is formed by a high-speed one-step method so that a sufficient amount of winding can be obtained in a package having a good winding shape without occurrence of yarn breakage during drawing and heat treatment. It can be wound up, and can be manufactured stably with good productivity and industrially.
[Brief description of the drawings]
FIG. 1 is a schematic process diagram showing one embodiment of a production method of the present invention.
[Explanation of symbols]
Y Yarn 1 Spinneret 2 Cooling air spraying device 3 Cylindrical heating device 4 Oil supply device 5 First roller (take-off roller)
6 2nd roller 7

Claims

Polyester composed mainly of polytrimethylene terephthalate is melt-spun from a spinneret, and the spun yarn is cooled and solidified once, then passed through a cylindrical heating device having an internal atmosphere temperature of 120 to 220 ° C., heat treated, and again A process for producing a polyester fiber, characterized in that after cooling, the yarn is taken up at a take-up speed of 3000 m / min or more, subjected to relaxation heat treatment at a relaxation rate of 4 to 12%, and then wound.