JPS61160417A - Production of polyhexamethylene adipamide fiber - Google Patents

Abstract

PURPOSE:To produce the titled fiber having excellent tenacity, dimensional stability and fatigue resistance, by specifying the polymerization degree of the polymer, the position of the collection point of spun yarn, and the spinning speed, and winding the spun yarn without using a take-up roller under specific draw ratio and single filament denier of the drawn yarn. CONSTITUTION:A molten polyhexamethylene adipamide having a relative viscosity (VR) of 60-90 in formic acid is extruded from a nozzle, passed through a cooling zone, applied with a spinning lubricant at a point lower than the spinneret by >=4m, and collected. The collected yarn is wound at a winding speed W(m/min) without using a take-up roll (5,100-30VR<=W<=4,700-20VR). The yarn is then drawn at a draw ratio Dr(>=3.30-3W/8,000) to obtain the objective drawn yarn having single filament fineness of 2.0-3.5 denier.

Description

【発明の詳細な説明】 〈産業上の利用分野〉 本発明はポリヘキサメチレンアジパミド繊維を製造する
に際し、高速で紡糸し、それを延伸して安定的に高強力
糸を得ると共に、設備的にも安価に上記高強力糸を製造
する方法に関する０本発明によって得られた糸は、強度
、寸法安定性、耐疲労性に優れ罠新しい特性を有してお
り、タイヤコード、コンベアベルト等の補強材として優
れた性能を発揮するものである〇 〈従来の技術〉 ポリアミド繊維は、その高強度と耐久性及びゴムとの接
着性の良好な性質の故に、タイヤ等、ゴム製品の補強材
として広範囲に用いられている。Detailed Description of the Invention <Industrial Application Field> The present invention involves spinning at high speed and drawing it to stably obtain a high-strength yarn when producing polyhexamethylene adipamide fibers. The yarn obtained by the present invention has excellent strength, dimensional stability, and fatigue resistance, and has new properties, and can be used in tire cords, conveyor belts, etc. 〇〇〈Conventional technology〉 Due to its high strength, durability, and good adhesion to rubber, polyamide fibers are used as reinforcement materials for rubber products such as tires. It is widely used as

近年、タイヤにも多様性が要求されるにおよび。In recent years, tires are also required to be more versatile.

補強材にも様々な特性が求められる工うになり九〇この
時点において；ポリアミトメイヤコードの欠点の１つは
、寸法安定性の低いことにある０ポリアミドのうちでも
、ポリカブラミドよりもポリヘキサメチレンアジパミド
が優れてｂる点は１寸法安定性及び耐熱性にある。At this point in time, reinforcing materials are required to have a variety of properties; one of the disadvantages of polyamide cords is their low dimensional stability.Among polyamides, polyhexamethylene is preferred over polycabramide. Adipamide is superior in its one-dimensional stability and heat resistance.

最近１寸法安定性を更に向上させるために、タイヤコー
ド用原糸のような太デニールのものにおいても、高速で
の紡糸が検討されている。高速紡糸に工り寸法安定性や
耐疲労性が向上することは、ポリエチレンテレフタレー
トについて特開昭５３−５８０３１号、ポリカプラミド
について特開昭５７−１９１）３７号、ポリヘキサメチ
レンアジパミドについて特開昭５８−６００１２号に開
示されているとおシである。タイヤコード用原糸の高速
紡糸は、ポリエチレンテレフタレートについては丁でに
実用段階であるが、ボリアずドについては現在開発の段
階にある。Recently, in order to further improve the one-dimensional stability, high-speed spinning is being considered even for thick denier fibers such as yarn for tire cords. The improvement of dimensional stability and fatigue resistance during high-speed spinning has been reported in JP-A-53-58031 for polyethylene terephthalate, JP-A-57-191) 37 for polycapramide, and JP-A-57-191) for polyhexamethylene adipamide. This is disclosed in No. 58-60012. High-speed spinning of raw yarn for tire cords is only at the practical stage for polyethylene terephthalate, but is currently in the development stage for polyethylene terephthalate.

高速紡糸へのポリアミドの対応の遅れは次の工うな理由
による。即ち、紡糸中の糸条に水分を水蒸気の状態で強
制的に付与しないと、未延伸糸の吸湿にＬる膨潤の沈め
に巻き取れない領域があることや、糸物性の改善がポリ
エチレンテレフタレートのように顕著でないことなどで
あるｎまた、ポリアミドの場合に特に顕著であるが、紡
糸速度？高速にすると、高強度を得ることが著しく難し
くなる。これは未延伸糸中に生底する結晶の増加や、紡
出単糸の横断面方向の内外層で配向の違いが生ずること
に起因している。この問題の解決のために、特開昭５８
−６００１２号に示されているように、紡口下に加熱帯
域を設け７？ニジ。The delay in adapting polyamide to high-speed spinning is due to the following reasons. In other words, unless moisture is forcibly added to the yarn in the form of steam during spinning, there are areas where undrawn yarn cannot be wound due to moisture absorption and swelling, and improvements in yarn physical properties cannot be achieved with polyethylene terephthalate. Also, this is particularly noticeable in the case of polyamides, but the spinning speed is not as noticeable as in the case of polyamides. Higher speeds make it significantly more difficult to obtain high strength. This is due to an increase in the number of raw crystals in the undrawn yarn and a difference in orientation between the inner and outer layers in the cross-sectional direction of the spun single yarn. In order to solve this problem,
As shown in No. 60012, a heating zone is provided under the spinneret 7? Niji.

単糸デニールを従来の延伸糸での６デニールエりも小さ
くするなどの手段が採用される。Measures are taken such as reducing the single yarn denier by 6 denier than the conventional drawn yarn.

未延伸糸の吸湿膨潤のために巻取りできない点について
は、強制的に水蒸気全付与したり、引き取り後、引き続
いて部分的に延伸して巻取るなどの方策が採用されてい
る。しかし、部分的に延伸すると言えども、安定的に延
伸するためには加熱ロールが必要であり、高速回転の加
熱ロールの使用は設備費用の点からも運転費用の点から
も高価になる。When the undrawn yarn cannot be wound due to moisture absorption and swelling, measures such as forcibly applying water vapor to the yarn completely or partially stretching the yarn after taking it off and then winding it are adopted. However, even if the film is partially stretched, heated rolls are required for stable stretching, and the use of high-speed rotating heated rolls is expensive both in terms of equipment costs and operating costs.

一方、設備的には、高デニールの紡糸の故に、エアサク
シ璽ンガンの糸条引き改シ能力が、引き覗シロール速度
に追随しなくなり、糸立て作業が困難になるという問題
が発生する。この解決のために、糸立て作業を比較的低
速で行い、作業完了後、引き取りロール及び巻敬機の速
度を所定の速度まで上げるという方法が採用される。し
かしながら、この方法では、ポリマーのロスが多くなシ
。On the other hand, in terms of equipment, due to the high denier spinning, the yarn drawing and reforming ability of the air succinct gun cannot keep up with the speed of the pruning yarn roll, making it difficult to set up the yarn. To solve this problem, a method is adopted in which the thread stand operation is performed at a relatively low speed, and after the work is completed, the speeds of the take-up roll and winder are increased to a predetermined speed. However, this method involves a lot of polymer loss.

設備的にも複雑な計装設備が要求される。In terms of equipment, complex instrumentation is required.

〈発明が解決しょうとする問題点〉 本発明は前述の＝うｌ従来技術の問題点を解決しょうと
するものである０即ち、本発明者は、高速紡糸によるポ
リヘキサメチレンアジパミド糸の製造方法について鋭意
検討の結果、ポリマの重合度、紡糸糸条の集束点の位置
、紡糸速度？特定し、引き取りロールを介さず巻取るこ
とに工り、作業性を極めて容易にし、良好な形状の未延
伸糸パッケージ？得ることができることを見出し、加え
て、延伸比と延伸糸の単糸デニールを特定することによ
り、良好に高強度糸を得ることができるとの知見？得て
、本発明に到達し罠。<Problems to be Solved by the Invention> The present invention attempts to solve the above-mentioned problems in the prior art. Namely, the present inventor has developed a method for producing polyhexamethylene adipamide yarn by high-speed spinning. After careful consideration of the manufacturing method, we found that the degree of polymerization of the polymer, the position of the convergence point of the spun yarn, and the spinning speed were determined. Undrawn yarn package with a good shape that is extremely easy to work with and winds without using a take-up roll. In addition, it was discovered that by specifying the drawing ratio and single yarn denier of the drawn yarn, it was possible to obtain a high-strength yarn. Obtain the invention and reach the trap.

即ち、本発明の目的は、新しい特性を有するボリヘキサ
メチレンアジパばド高強力糸を安定的に得ると共に、設
備的にも安価な、ポリマロスの少本発明は、前述の問題
点を解決するπめに、次の構ｇを有する。即ち、実質的
にポリへキサメチレンアジパミドから成る繊維を製造す
る方法において、蟻酸相対粘度が６０乃至９０のポリへ
キサメチレンアジパミドの溶融物を、多数のノズル乞Ｍ
する紡口から押出し、冷却域を通過させて後、紡口から
４諷以上下方で、紡糸油剤を付与して糸条を集束し、引
き取りロールを経ることなく、王妃（１）式の条件を満
た丁速度Ｗで直接に巻取機で巻取り、しかる後下記（２
）式の条件？満π丁延伸比Ｄｒで延伸し、単糸ｍ度が２
．０乃至３．５ｆニールである延伸糸を得ることを特徴
とする。That is, an object of the present invention is to stably obtain a polyhexamethyleneadipate high strength yarn having new properties, and which is inexpensive in terms of equipment and has a small amount of polymer loss.The present invention solves the above-mentioned problems. At π, we have the following structure g. That is, in a method for producing fibers consisting essentially of polyhexamethylene adipamide, a melt of polyhexamethylene adipamide having a formic acid relative viscosity of 60 to 90 is passed through a number of nozzles.
The yarn is extruded through a spinneret, passed through a cooling zone, and then a spinning oil is applied at least 4 threads below the spinneret to converge the yarn, and the condition of the Queen (1) method is met without passing through a take-up roll. Wind it up directly with the winder at the filling speed W, and then the following (2)
) expression condition? Stretched at full pi drawing ratio Dr, single yarn m degree is 2
．． The method is characterized by obtaining a drawn yarn having a 0 to 3.5 f kneel.

５１００−３０ＶＲ：５Ｗ≦４７００−２０ＶＲ（１）
３、３０−−　−　Ｗ≦Ｄｒ　　　　　　　　（２）８
０υ０ ここで、ＶＲはＡＳＴＭ　Ｄ−７８９に従って測定した
蟻散相対粘度であ夛、Ｗは巻覗速度Ｃｍ／分）であり、
Ｄｒは延伸比（延伸後の弛緩率は含まない）である。5100-30VR: 5W≦4700-20VR (1)
3, 30-- - W≦Dr (2)8
0υ0 Here, VR is the dispersion relative viscosity measured according to ASTM D-789, W is the winding speed Cm/min),
Dr is the stretching ratio (not including the relaxation rate after stretching).

本発明に係るポリヘキサメチレンアジパミドは。The polyhexamethylene adipamide according to the present invention is.

一般のタイヤコード用原糸のように、ハロゲン化鋼の如
き無機の熱安定剤、メルカプトベンゾイミダゾールの如
き有機化合物の熱安定剤、その低酸ｆヒチタン、シリカ
等の改質剤を含んでいても良く。Like general yarn for tire cords, it contains inorganic heat stabilizers such as halogenated steel, organic compound heat stabilizers such as mercaptobenzimidazole, and modifiers such as low-acid titanium and silica. Good too.

ま７ｃ５％程度の共重合成分を含んでいるものでもさし
つかえない。It is also possible to use a material containing about 7c5% of a copolymer component.

以下においては、始めに、本発明のうち、未延伸糸パッ
ケージの形状及び糸立て作業に係る部分について説明し
、次いで紡糸及び延伸について工程を追って詳細に説明
する。In the following, parts of the present invention related to the shape of the undrawn yarn package and the yarn stand-up operation will first be explained, and then spinning and drawing will be explained step by step in detail.

紡糸後、未延伸の状態で巻取られたポジアミド糸条は、
未だ水分を吸収する余地を残している。After spinning, the posiamide yarn is wound in an unstretched state.
It still has room to absorb moisture.

この状態から未延伸糸が吸湿すると、糸条は膨潤し、そ
の長さを増丁。膨潤の程度は未延伸糸の分子配向の程度
によって異なり、配向度の大きい程膨淘は小さい。一般
には、高速で紡糸する程、未延伸糸の配向は大きくなり
でおり、ある速度以上では膨潤は問題にならない。逆に
極めて低紡速では、巻取られるまでの吸湿量が多く１巻
取シ以降の吸湿量が少なりため膨潤は小さい。膨潤が大
きい範囲では巻取後の未延伸糸パッケージの形状を保持
することが困難になり、巻取り不能となる。When the undrawn yarn absorbs moisture from this state, the yarn swells and its length is increased. The degree of swelling varies depending on the degree of molecular orientation of the undrawn yarn, and the greater the degree of orientation, the smaller the swelling. Generally, the higher the spinning speed, the greater the orientation of the undrawn yarn, and swelling does not become a problem above a certain speed. On the other hand, at extremely low spinning speeds, the amount of moisture absorbed before winding is large and the amount of moisture absorbed after the first winding is small, so that swelling is small. If the swelling is large, it becomes difficult to maintain the shape of the undrawn yarn package after winding, and winding becomes impossible.

巻取り不能の紡速域は、巻取室温湿度、ポリマ重合度、
糸条酸度など様々な要因によって違ってくるが、引き取
りロールを介すると、一般には。The spinning speed range where winding is not possible depends on the winding room temperature, humidity, polymerization degree,
It depends on various factors such as yarn acidity, but in general, it will pass through the take-up roll.

１０００ｇ／分から３５００霞／分の範囲である〇この
領域で巻取ろうとすると１強制的に水分を付与する必要
があるが、２０００ｍ／分を越える速にでは、糸条の随
伴空気流が多いために１強制的な水分付与５ｌｉｔ、＜
なってくる。The range is from 1,000 g/min to 3,500 haze/min. If you try to wind the yarn in this range, it is necessary to forcibly add moisture, but at speeds exceeding 2,000 m/min, there is a large amount of air flow accompanying the yarn. 1 forced moisture application 5 liters, <
It's coming.

未延伸糸パッケージの形状を保持するには、上記の外に
１巻取９Ｖｋの糸条の放縮も重要な要因である。放縮が
大きいとパッケージは締めつけられ、側面方向へはみ串
型ことになる。極端な場合には、巻取りの紙管を歪ませ
、巻取機のスピンドルから紙管をとり外型ことができな
くなる０放縮の管理は、一般には１巻取張力を適当な値
に保つことによりて為される。紡糸速度が高速になると
１巻取張力を適当な壇にするために、引き磯夛ロールと
巻取機の間で弛緩しながら巻取ることになるが、引き取
りロールまでの張力によって内在された歪が巻取９まで
に解放されず１巻取後に放縮し、パッケージ形状を悪化
させる場合も出てくる。この現象はポリアミドの場合に
特に顕著である。この現象を改善するには９巻取９前の
糸条を加熱して歪の解放を加速しても良いが、引き取り
ロールまでの張力を低くして内在する歪？小さくする手
段が有効であり、その張力に対して最も寄与の大きい空
気抵抗を減少させる罠め、紡糸糸条の集束点を紡口に近
づける手段が採用されている。これによシ、ポリアミド
の場合６０００　ｒＩＬ／分程麓までの高速紡糸が実現
できる。In addition to the above, release and contraction of the yarn of 9Vk per winding is also an important factor in maintaining the shape of the undrawn yarn package. If the shrinkage is large, the package will be tightened and skewered laterally. In extreme cases, the paper core for winding is distorted and the paper core cannot be removed from the spindle of the winder and the outer shape becomes impossible.Managing zero release generally involves keeping the winding tension at an appropriate value. It is done by When the spinning speed becomes high, in order to maintain an appropriate tension for each winding, winding is performed while loosening between the pulling roll and the winding machine, but the inherent strain caused by the tension up to the take-up roll There are cases where the package is not released by the time of winding 9 and is released and shrunk after the first winding, deteriorating the package shape. This phenomenon is particularly noticeable in the case of polyamides. To improve this phenomenon, it is possible to accelerate the release of strain by heating the yarn before winding 9, but by reducing the tension up to the take-up roll, it is possible to reduce the inherent strain. It is effective to reduce the tension, and methods are used to reduce the air resistance, which contributes most to the tension, and to bring the convergence point of the spun yarn closer to the spinneret. This makes it possible to achieve high-speed spinning of up to 6000 rIL/min in the case of polyamide.

即ち、ポリアミドの場合、高速域での紡糸は３５ＵＯｍ
１５＋乃至６０００ｆｉ／分の範囲となるが。That is, in the case of polyamide, spinning at high speed is 35 UOm.
It ranges from 15+ to 6000 fi/min.

高デニールの紡糸では、エアサクションガン゛の能力の
点から間頃がある。For high denier spinning, there is a certain range in terms of the ability of air suction guns.

タイヤコード用原糸の製造では、延伸糸で６３０デニ一
ル程度のものでも、未延伸糸では、１０００乃至１５０
０デニ一ル程度もあり、エアサクションガンに使用する
圧気圧を比較的経済的な６．０ｋｆ／ｉＧとすれば、４
０００ｆｒ＆／分が能力上限である。糸立て作業のしや
すさを考慮すると、更に低い速度までである。正気圧力
を高くすると能力は向上するが、圧気コストが増大した
り、場合によってはエアサクシ１ンガンのための特別の
圧気設備を設ける必要が生じてくる〇 我々は、ポリへキサメチレン・アジパミドの高速紡糸の
特性を生かしつつも高強度を得ること、及びエアサクシ
ョンガンの能力を補うことな・く、糸立て作業性を良好
にすることを勘案し、鋭意検討の結果、本発明に到達し
７Ｃ。In the production of yarn for tire cords, even if the drawn yarn is about 630 denier, the undrawn yarn is about 1000 to 150 denier.
If the pressure used for the air suction gun is set to 6.0kf/iG, which is relatively economical, then 4.
000fr&/min is the upper limit of capacity. Considering the ease of thread stand work, the speed is even lower. Increasing the normal pressure improves the capacity, but it also increases the air pressure cost, and in some cases, it becomes necessary to install special air pressure equipment for the air spool gun. As a result of intensive research, we have arrived at the present invention, taking into consideration the need to obtain high strength while taking advantage of the characteristics of 7C, and to improve thread stand workability without supplementing the ability of the air suction gun.

ポリへキサメチレンアジパミド紡出糸条は、前述のとお
り、１０００乃至３５００ｎｓ／分の巻取速度では、吸
湿による膨潤のため、未延伸糸パッケージの形状保持が
困難である。一方において。As described above, polyhexamethylene adipamide-spun yarn swells due to moisture absorption at a winding speed of 1000 to 3500 ns/min, making it difficult to maintain the shape of the undrawn yarn package. On the one hand.

紡出糸条に加えられ罠張力によって、巻鍛後に放縮が発
現する０我々は、検討の結果、この放縮と吸湿による膨
潤會バランスさせれば、３５００ｖ’分以下の巻取速度
においても、未延伸糸パッケージの形状を保持できる方
法があることを見出した。Due to the trap tension applied to the spun yarn, it will cause shrinkage after winding and forging.As a result of our studies, we have found that if we balance this release and swelling due to moisture absorption, it will work even at winding speeds of 3500v' or less. discovered that there is a method that can maintain the shape of an undrawn yarn package.

この実現のためには、ポリマの蟻酸相対粘度Ｃ以下ＶＲ
と略す）即ち重合度に対して巻取速度を限定すること、
及び紡口から紡出糸条の集束点までの距離を特定する必
要がある０更に、引き取りロールを介さず、直接に巻取
機で巻取る必要がある。To achieve this, the formic acid relative viscosity of the polymer must be less than VR
(abbreviated as ), that is, limiting the winding speed according to the degree of polymerization,
Furthermore, it is necessary to specify the distance from the spinneret to the convergence point of the spun yarn.Furthermore, it is necessary to wind the yarn directly with a winder without using a take-up roll.

本発明の目的のうち、高強度のポリヘキサメチレンアジ
パミド糸を得る目的に対しては、高速域とは言え比較的
低速度とするのが良い。その意味で３５００ｍ／分以下
で巻取れることは３１要である。この領域の速反で良好
な未延伸糸上巻取るためには、紡口から紡出糸条集束点
までの距離ｔ−４ｍ以上として、前記（１）式の条件を
満す巻取速度で、引き喉クロールを介さず直接に巻取機
に巻取る必要がある。Among the objects of the present invention, for the purpose of obtaining a high-strength polyhexamethylene adipamide yarn, it is preferable to set the speed to a relatively low speed, although it is in a high speed range. In that sense, being able to wind at a speed of 3500 m/min or less is 31 requirements. In order to wind the undrawn yarn with good speed in this region, the distance from the spinneret to the spun yarn convergence point is t-4 m or more, and the winding speed satisfies the condition of formula (1) above. It is necessary to wind the material directly onto the winder without going through a pull throat crawl.

巣に未延伸糸パッケージ形状を良好に保持するのみなら
ば一１紡口から糸条集束点までの距離は２ｍ程度でも良
いが、１００ｖｉ−超える工うな多数の巣糸数の糸条を
紡糸する場合には、上記距離が４翼以上はないと糸条の
冷却不足により、単糸間の融着等により、未延伸糸段階
では毛羽の発生、延伸時には毛羽の発生や糸切れにつな
がる。If the shape of the undrawn yarn package is to be maintained well in the web, the distance from the spinneret to the yarn convergence point may be about 2 m, but when spinning yarn with a large number of webs, such as exceeding 100 vi. If the above-mentioned distance is not 4 blades or more, insufficient cooling of the yarn will result in fusion between single yarns, leading to the generation of fluff in the undrawn yarn stage, and generation of fluff and yarn breakage during drawing.

巻取速度が（１）式ニブ低い範囲では巻取糸条は膨潤し
て糸切れとなシ、巡に高い範囲では放縮にＬりてパッケ
ージ側面方向にふくらみ、延伸性も低下するＯ ＶＲが大きい程、適正範囲が低い速度範囲となるのは、
巻取後の放縮が大きい罠めである。ポリヘキサメチレン
アジパミドの場合、高速で紡糸すると、ＶＲが高い方が
、未延伸糸の配向は低くなる。これは後屈、折率が小さ
くなること１強度が低くな９、伸度が大きくなること工
夛知ることができる。この理由は１本来ならば紡糸張力
にニジポリマが流動を起し、配向すべきところを、ＶＲ
が高いと流動粘性が大きいため配向しないで、その張力
を歪として内在し７Ｃまま巻取られ、巻取り後放縮とし
て解放され、低配向、低強度、高伸度となるものと考え
られる〇 （１）式の条件を満しても、引き覗シロールを使用する
と、引き取りロールと巻取機の間で放縮する部分が生じ
１巻取れなくなる。When the winding speed is low, the winding yarn swells and breaks, and when the winding speed is high, it shrinks and swells toward the side of the package, and the drawability decreases. The larger the speed range, the lower the appropriate range.
It is a trap that has a large amount of shrinkage after winding. In the case of polyhexamethylene adipamide, when spinning at high speed, the higher the VR, the lower the orientation of the undrawn yarn. This can be understood from the following effects: back refraction, the refractive index decreases, the strength decreases9, and the elongation increases. The reason for this is 1. The rainbow polymer flows due to the spinning tension and should be oriented, but the VR
If it is high, the flow viscosity is high, so it is not oriented, but the tension is internalized as strain, and it is wound up as it is at 7C, and is released as contraction after winding, resulting in low orientation, low strength, and high elongation.〇 Even if the condition of formula (1) is satisfied, if a pull-through roll is used, there will be a part that is released and contracted between the take-up roll and the winder, making it impossible to take one roll.

本発明は引き取りｒ：１−ルを使用しないために、２つ
の長所ｔ−有する。１つは設備コストが安価となること
であり、もう１つはエアサクシ曹ンガンの能力が７ｋｆ
／ｍＧ以下でも、何ら県立て作業上の問題にならないこ
とである。The present invention has two advantages because it does not use take-offs. One is that the equipment cost is low, and the other is that the air saxophone's capacity is 7kf.
/mG or less does not pose any problem for prefectural work.

高強度糸を得るためには、更に制約が必要である。以下
に、紡糸延伸の過程に従って説明する、ポリヘキサメチ
レンアジパミドは、タイヤコード用原糸の製造において
は、ハロゲン化銅などの熱安定剤が加えられる０ポリマ
のＶＲは６０乃至９０が良い。これは高強度を得る罠め
及びポリアミドの特徴である高耐疲労性の罠めに必要で
あるＯＶＲが６０ニジ低くなると特に耐疲労性が改善で
きない。ＶＲが９０工９大きくなると延伸が難しくな９
、高強度を達成しにくい。Further constraints are required to obtain high strength yarns. Polyhexamethylene adipamide, which will be explained below according to the process of spinning and drawing, has a VR of 60 to 90 for the zero polymer to which a heat stabilizer such as copper halide is added in the production of yarn for tire cords. . This is because the fatigue resistance cannot be particularly improved if the OVR, which is necessary for a trap to obtain high strength and a trap to have high fatigue resistance, which is a characteristic of polyamide, is lowered by 60 degrees. Stretching becomes difficult as the VR increases by 90 degrees.9
, high strength is difficult to achieve.

ポリマを２９０乃至３２０℃に融解し、多数のノズルを
有する紡口りり吐出するロタイヤコード用原糸製造に利
用される紡口のノズルの数は、一般には１００以上であ
る。この際、延伸糸として要求される繊度に従って、延
伸糸の単糸デニールが２．０乃至３．５デニールとなる
ように、ポリマの吐出量、及び紡口のノズルの数を選択
する必要がある。延伸糸の単糸デニールがこの範囲を外
れると、充分な延伸糸強度が得られない。延伸糸の単糸
が３．５デニールを越える吐出量及びノズル数の組合せ
を選択すると、未延伸糸の単糸の内外層の配向斑が影響
して、充分な延伸ができない。延伸糸の単糸が２．０デ
ニ一ル未満で延伸性が悪い理由は明瞭ではないが、単糸
が細すぎる九め、小さな欠点が糸切れにつながるためで
あろうと考えられるＯ 押出時のポリマ温度が２９５℃以上で、ＶＲが７０以下
であれば、必ずしも紡口直下に加熱帯域を設ける必要は
なく、紡口表面が冷却風に１って冷却されない程度に保
護されていればよい。ポリマ温度が低い場合や、ＶＲが
７０に越えるような場合には、紡口直下の加熱帯域は有
効であるー吐出された糸条は冷却風によって冷されるが
、冷却風は円周方向から紡出糸条に当てても良いし、片
側から紡出糸条に直交するようＶｃ轟てても良いが、こ
れらの場合で、紡口におけるノズルの配列を考慮する必
要がある。前者の場合には、ノズルは円周に沿って配列
する。後者の場合は、冷却風の流れの方向に対し、やや
斜向する方向に配列する。好ましくは、左右対称として
、中央あるいは数個所に、冷却風を通り易くするための
、ノズルのない帯域を冷却風の流れ方向に沿って設ける
のが良い０これによって単糸間の冷却の均一化と加速＝
２ａることができ、単糸間の融着ｔ−４防ぐことができ
る。The number of nozzles in a spinneret used for producing yarn for rotary cord, in which a polymer is melted at 290 to 320° C. and discharged through a spinneret having a large number of nozzles, is generally 100 or more. At this time, it is necessary to select the discharge amount of the polymer and the number of nozzles in the spinneret so that the single filament denier of the drawn yarn is 2.0 to 3.5 denier according to the fineness required for the drawn yarn. . If the single filament denier of the drawn yarn is outside this range, sufficient drawn yarn strength cannot be obtained. If a combination of the discharge amount and the number of nozzles is selected such that the single yarn of the drawn yarn exceeds 3.5 denier, sufficient stretching cannot be achieved due to uneven orientation of the inner and outer layers of the single yarn of the undrawn yarn. The reason why the drawn yarn has poor drawability when the single yarn is less than 2.0 denier is not clear, but it is thought that it is because the single yarn is too thin and small defects lead to yarn breakage during extrusion. If the polymer temperature is 295° C. or higher and the VR is 70 or lower, it is not necessarily necessary to provide a heating zone directly below the spindle, and it is sufficient that the surface of the spindle is protected to the extent that it is not cooled by the cooling air. When the polymer temperature is low or the VR exceeds 70, a heating zone directly below the spinneret is effective - the discharged yarn is cooled by cooling air, which is directed from the circumferential direction. It may be applied to the spun yarn, or Vc may be applied to the spun yarn from one side so as to be perpendicular to the spun yarn, but in these cases, it is necessary to consider the arrangement of the nozzles at the spinneret. In the former case, the nozzles are arranged along the circumference. In the latter case, they are arranged in a direction slightly oblique to the direction of the flow of cooling air. Preferably, a nozzle-free zone is preferably provided in the center or at several locations along the flow direction of the cooling air to facilitate the passage of the cooling air. This will ensure uniform cooling between the single yarns. and acceleration =
2a, and fusion between single yarns can be prevented.

紡出糸条の集束は紡口から４＋ｓ以上下方で行う。The spun yarn is bundled at least 4+s below the spinneret.

この理由は、前述のとおり、糸条の充分な冷却のために
このような距離が必要とされるからである。The reason for this is that, as mentioned above, such a distance is required for sufficient cooling of the yarn.

単糸数が少ないともつと早く冷却されるが、単糸数が１
００を越えると４鱒以上が必要となってくる０紡口下４
ｍ以上の距離の全てに渡って冷却風を吹き出す必要はな
く、随伴流に工って冷却できる。冷却が不充分だと未延
伸糸単糸表面の損傷が大きく、巻取や延伸で毛羽になっ
たり、糸切れを起したりする。If the number of single threads is small, it will cool down quickly, but if the number of single threads is 1
If you exceed 00, you will need 4 or more trout 0 spindle lower 4
It is not necessary to blow cooling air over the entire distance of m or more, and cooling can be achieved by creating an accompanying flow. If the cooling is insufficient, the surface of the undrawn yarn single filament will be seriously damaged, resulting in fuzzing or yarn breakage during winding and stretching.

冷却後に糸条に付与する紡糸油剤′は、非水系でも富水
系でも良いが、糸条の集束点の直前で、オイリングロー
ル？多段に用いて付与するのが良い〇紡糸油剤を付与す
る前に糸条を集束させようとすると、集束の罠めのガイ
ド等に工り、糸条表面の損傷が起って、毛羽の発生や糸
切れにつながり。The spinning oil applied to the yarn after cooling may be either non-aqueous or water-rich, but it should be applied to an oiling roll just before the yarn convergence point. It is best to apply it in multiple stages. If you try to bundle the yarn before applying the spinning oil, it will act as a guide for the binding trap, damaging the yarn surface and causing fuzz. This may lead to thread breakage.

高強度を得ることが困難になる０ 紡糸油剤を付与し罠糸条を前記（１）式を満たす速度で
、引き取りロールを介さず、直接に巻取機にて巻取る。It becomes difficult to obtain high strength.0 A spinning oil is applied and the trap yarn is wound directly with a winding machine at a speed that satisfies the above formula (1) without passing through a take-up roll.

（１１式の下限より遅い速度では、本方法と言えども、
巻取中の吸湿による糸条の膨潤のために、未延伸糸パヅ
ケージ形状の保持は困難である。上限を越える速度では
１巻取張力が０．４ｔ／デニールを越える大きな籠とな
るため、未延伸糸パッケージが横方向につぶれた形状と
なる、と同時に延伸性も低下する〇 このようにして得られた未延伸糸に対して、実質的に前
記（２）式を満す延伸を与える必要がある０延伸比が（
２）式の下限以下の場合には、延伸糸強度は、延伸後に
製品とするまでの放縮あるい社弛緩率によって異なるけ
れども、９憾程度の弛緩率である場合には、高々８２／
デニールであり、得られる糸は強度的に不十分である０ 高強度糸を得るために、延伸は、多段にわけて行うこと
が望ましい０延伸は熱延伸で行う。糸条に対する熱付与
は、熱ロール又は熱板のどちらでも採用できるし、双方
の組合せでも良い。高強度糸を得るために、熱付与の温
度は、通常の引き覗り速度４００乃至７００　ｍ／分で
紡糸した場合に比べ、１０乃至３０℃程度高い温度でか
つ融点以下の温度とすることが好ましい０これは、延伸
糸巣糸歇度金２．０乃至３．５デニールとして、未延伸
糸単糸の内外層差？小さくしても、なお、未延伸糸には
微結晶が多く、延伸に際して分子のモビリティが低い罠
め、＠度を上げて延伸し易くする必要があることによる
。(At speeds slower than the lower limit of equation 11, even with this method,
Due to swelling of the yarn due to moisture absorption during winding, it is difficult to maintain the shape of the undrawn yarn pad cage. If the speed exceeds the upper limit, the winding tension exceeds 0.4 t/denier, resulting in a large basket, which causes the undrawn yarn package to become collapsed in the transverse direction, and at the same time, the drawability decreases. The zero draw ratio that is required to give the undrawn yarn a draw that substantially satisfies the above formula (2) is (
If the lower limit of formula 2) is below, the drawn yarn strength will vary depending on the relaxation rate or relaxation rate after stretching until it is made into a product, but if the relaxation rate is about 9 degrees, it will be at most 82/
denier, and the resulting yarn has insufficient strength. In order to obtain a high-strength yarn, it is desirable to carry out the drawing in multiple stages. The drawing is performed by hot drawing. Heat can be applied to the yarn using either a hot roll or a hot plate, or a combination of both. In order to obtain a high-strength yarn, the temperature at which heat is applied should be approximately 10 to 30°C higher than when spinning at a normal spinning speed of 400 to 700 m/min and below the melting point. Preferably 0 This is the difference between the inner and outer layers of a single undrawn yarn, with a drawn yarn density of 2.0 to 3.5 denier. Even if the yarn is made smaller, there are still many microcrystals in the undrawn yarn, which causes low molecular mobility during drawing, and it is necessary to increase the degree to make drawing easier.

尚１本発明のように、単糸像度が従来の６デニールよ＃
）も小さい２．０乃至３．５デニールの延伸糸を得よう
とすると、例えば、１８９０デニールの延伸糸では、単
糸数５４０乃至９４５本となり、１つの紡口から吐出す
れば設備の点で大がかりなものとなる。また、紡口の大
きさに制約がある中でこれだけのノズルを設けて紡糸し
ようとすると。In addition, as in the present invention, the single thread image quality is higher than that of the conventional 6 denier.
), if you try to obtain a drawn yarn of 2.0 to 3.5 deniers, for example, for a drawn yarn of 1890 denier, the number of single yarns will be 540 to 945, and if you discharge it from one spinneret, it will require a large amount of equipment. Become something. Also, if you try to spin yarn with this many nozzles while there are restrictions on the size of the spinneret.

単糸間の冷却を均一に行うことが難しく、融着も起り易
くなる０これを回避する丸め、２個以上の紡口に分けて
吐出し、未延伸糸巻取りの際に合糸して巻取る方法や、
未延伸糸巻取りはｌ紡口毎として、延伸の際に複数の未
延伸糸パッケージＬ９引き出した糸条を合糸して延伸す
る方法、更には延伸糸を合糸する方法等を採用すること
ができる。It is difficult to uniformly cool the single yarns, and fusion is likely to occur.To avoid this, rounding, discharging the yarns separately from two or more spinnerets, and doubling and winding the undrawn yarns when winding the undrawn yarns. how to take it,
The undrawn yarn can be wound up for each spindle, and a method of plucking and drawing a plurality of undrawn yarn packages L9 pulled out during drawing, or a method of doubling the drawn yarn, etc. can be adopted. can.

ポリアミドの場合、タイヤコード用原糸としては。In the case of polyamide, as yarn for tire cords.

１２６０デニールもしくは１８９０デニールの原糸が王
として用いられているため、延伸糸換算で３１５．４２
０又は６３０デニールとしてｌ紡ロ工９吐出する方法が
実際の生産に対して有効である。Since raw yarn of 1260 denier or 1890 denier is used as the king, it is 315.42 in terms of drawn yarn.
The method of discharging 1 spinner 9 as 0 or 630 denier is effective for actual production.

〈実　施　例〉 以下に実施例により本発明を具体的に説明するが、本発
明はこれらの実施例に限定されるものではない。<Examples> The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples.

例　ｌ 熱安定剤として酢酸鋼を銅イオンとして７０ｐｐｍ　、
ヨウ化カリ１１０００ｐｐ？含む、ＶＲ４０，６０，８
０，９０のポリへキサメチレンアジパミドを用いて２９
８℃で紡糸し７（０２１０個の直径０６３１ｎＴｒＬ　
のノズルを有する紡口より吐出量Ｑｒ／分で吐出し、５
０ｍの長さの保温域を通した後、糸条走行方向にほぼ直
交する冷却風中全通し、冷却し友。冷却風吹出長は１．
６ｍである０紡口下４．５唇から４．８ｍの間に設けら
れた２段のオイリングロールで、含水系の紡糸油剤を、
油剤成分で１．０乃至１．５％’？付与した後、糸条金
集束し。Example l 70 ppm of copper ion in acetic steel as a heat stabilizer,
Potassium iodide 11000pp? Including, VR40,60,8
29 using polyhexamethylene adipamide of 0.90
Spun at 8°C to obtain 7 (0210 diameter 0631nTrL)
Discharged from a spindle having a nozzle at a discharge rate of Qr/min,
After passing through a heat-retaining area with a length of 0 m, the yarn is completely passed through cooling air that is almost perpendicular to the yarn running direction to be cooled. The cooling air blowing length is 1.
A two-stage oiling roll installed between 4.8 m from the 4.5 lip below the 0 spindle, which is 6 m long, is used to apply water-containing spinning oil.
1.0 to 1.5% of oil component? After applying, bundle the thread metal.

引き取りロールを介さず、２３１０，２４９０゜２７０
０．２９１０，３１００，３２９０゜３４９０．３９１
０Ｆｌｌ／分の速度で直接巻覗機で約１０ｋｆｔ巻取っ
た。未延伸糸パッケージ形状の良否にかかわらず、巻取
可能であつたものについては次の条件で延伸した。４対
の原熱ネルソンロール（以下ＮＲ）と＠ｌのＮＲの前に
張力付与のために１．５％の伸張を与えて第１ＮＲに糸
条勿送９込む供給ロールから成る延伸設備？用いた。未
延伸糸パッケージ３個りり引き出した糸条を合糸して延
伸した口１！ｌＮＲは８０℃、第２ＮＲは２４０℃、第
３及び第４ＮＲは２５０℃である。2310, 2490°270 without using a take-up roll
0.2910, 3100, 3290°3490.391
Approximately 10 kft was wound with a direct winder at a speed of 0Fll/min. Regardless of the quality of the undrawn yarn package shape, those that could be wound were drawn under the following conditions. Stretching equipment consisting of four pairs of raw heat Nelson rolls (hereinafter referred to as NR) and a supply roll that applies 1.5% elongation to impart tension before the first NR and feeds the yarn into the first NR. Using. Opening 1 where 3 undrawn yarn packages were pulled out, the yarns were combined and stretched! The first NR is 80°C, the second NR is 240°C, and the third and fourth NRs are 250°C.

麺３ＮＲと第４ＮＲ間の表面速皺比は０．９５で弛緩、
第４ＮＲと巻取機間は０．９５で弛緩であり。The surface wrinkling ratio between noodles 3NR and 4th NR is 0.95 and is relaxed.
The slack between the 4th NR and the winder is 0.95.

延伸比は供給ロールと第３ＮＲとの表面速度比で示す０
第２ＮＲと第３ＮＨの速度比は１．２として、延伸比の
変更は第１ＮＲと第２ＮＨの速度比を変更することに工
って行う友。尚、延伸糸の巻取速度は１５００ｍ／分で
一定とし罠。結果を第１表及び＠１図に示す。ここで用
いた延伸比は、糸切れ１罰の最大延伸比の約９５壬の延
伸比である。The stretching ratio is 0, which is indicated by the surface speed ratio of the supply roll and the third NR.
The speed ratio of the second NR and the third NH is set to 1.2, and the stretching ratio is changed by changing the speed ratio of the first NR and the second NH. The winding speed of the drawn yarn was kept constant at 1500 m/min. The results are shown in Table 1 and Figure 1. The draw ratio used here is a draw ratio of about 95 mm, which is the maximum draw ratio with one yarn breakage.

本実施例においては引き取りロールを使用していない罠
め、エアサクシ１ンガンとして帝人精機社＃５Ｇ６１０
ｔ−使用して、圧気圧５．０ｋｆ／ｍＧであっても、一
度の県立て失敗もな〈実施できた。In this example, Teijin Seiki Co., Ltd. #5G610 is used as a trap and air saxophone gun that does not use a take-up roll.
Using T-T, even at a pressure of 5.0 kf/mG, we were able to carry out the test without a single failure.

な訃、第１表の物性のうち、デニール、強度。Among the physical properties in Table 1, denier and strength.

伸度は、ＪＩＳＬ−１０１７に準拠して測定した０乾熟
収量率は１６０℃のオープン中に無荷重の状態で３０分
間放置し、取り出してから４時間放置し、糸長収縮公金
もとの糸長に対する比で表わしたものである。The elongation was measured in accordance with JISL-1017. The yield rate was determined by leaving the yarn open at 160°C for 30 minutes without any load, and then leaving it for 4 hours after taking it out. It is expressed as a ratio to yarn length.

以下余白 例　　２ ９Ｑｌと同様にＶＲ６０のポリへキサメチレンアジパミ
ドを紡出し、紡口から集束点までの伸距離を変更して巻
取フ罠。含水系の紡糸油剤を、厚み０．５■、長さ１５
＋ｎ＋のスリット状の油剤付与ノズルを用いて、付与率
１．２％となるように計量付与した。集束点はスリット
の下方８ｃＷＩである。巻取速度は３ｉ００ｆｉ／分で
ある。第２表に、ストロボを使用して観察し友未延伸糸
パンケージに発生する毛羽の量と、パッケージ形状を示
す。Below is a blank example 2. In the same way as 9Ql, polyhexamethylene adipamide of VR60 is spun, and the stretching distance from the spinneret to the convergence point is changed and the winding trap is carried out. Add water-containing spinning oil to a thickness of 0.5 cm and a length of 15 mm.
Using a +n+ slit-shaped oil agent application nozzle, the amount was applied at an application rate of 1.2%. The focal point is 8 cWI below the slit. The winding speed is 3i00fi/min. Table 2 shows the amount of fuzz generated in the undrawn yarn pancakes as observed using a strobe and the package shape.

未延伸糸パッケージに観察される毛羽は、単糸の冷却不
足に＝る単糸間の融着に起因している。The fluff observed in the undrawn yarn package is caused by fusion between the single yarns due to insufficient cooling of the single yarns.

紡口から集束点までの距離が３ｍ以下では１時々油剤付
与ノズルに、切れた単糸が付着している場合が認められ
た。When the distance from the spinneret to the convergence point was 3 m or less, it was occasionally observed that broken single yarns were attached to the oil application nozzle.

以下余白 第　　２　表 ９１Ｊ３（比較例） Ｍｌと同じ熱安定剤を含むＶＲ６０のポリヘキサメチレ
ンアジパミドを、２１０個のノズルを有する紡ロエク、
吐出量４５７１７分で押出し、引き取りロール速度３４
９０＋＋ａ／分１巻取速度３４９６ｓｓ／分で巻取るこ
とを試み罠０紡口がら集束点までの距離は５．１ｍｓ、
引き取りロールの表面粗度は５Ｓである。Below is the blank space 2 Table 91J3 (Comparative example) Polyhexamethylene adipamide of VR60 containing the same heat stabilizer as Ml was spun using a spinning process having 210 nozzles.
Extrusion with a discharge amount of 45,717 minutes, take-up roll speed of 34
Attempting to wind at a winding speed of 3496 ss/min, the distance from the trap 0 spindle to the focusing point was 5.1 ms.
The surface roughness of the take-up roll is 5S.

量大精機社製ＳＧ６１０のエアサクシボンガンを用いて
、圧気圧５．５１＃／ｊＧで県立てを行りたが、７回の
試行のうち２回しか成功しなか−）た〇しかも巻取開始
後、３０秒から６０秒の間に、巻取υ中の糸が水分を吸
収して膨潤し、パッケージの中央側に寄って糸切れした
。I tried to set the prefecture at a pressure of 5.51#/jG using a SG610 air sac gun made by Yondai Seiki Co., Ltd., but I was only successful in 2 out of 7 attempts. Between 30 seconds and 60 seconds after the start of winding, the yarn in the winding υ absorbed water and swelled, and the yarn broke near the center of the package.

例　４ 例１と同じ熱安定剤を含むＶＲ８０のポリへキサメチレ
ンアジパミドを、１４０個のノズルを有する紡口を用い
て、吐出量を変え、巻昧速度３１００ｍ／分、その他の
条件は例１と同様にして紡糸した。吐出量が４４０ｆ／
分以上の場合は。Example 4 Polyhexamethylene adipamide with a VR of 80 containing the same heat stabilizer as in Example 1 was produced using a spindle with 140 nozzles, the discharge rate was varied, the winding speed was 3100 m/min, and the other conditions were Spinning was carried out in the same manner as in Example 1. Discharge amount is 440f/
If it's more than a minute.

未延伸糸パッケージがやや膨潤ぎみであシ、５３０ｆ／
分では膨潤ぎみであると同時に、毛羽が散見されたが、
巻取９は可能であったため、全条件について延伸を実施
した０３個の未延伸糸パッケージより引き出した糸条を
合糸し、例１と同条件で延伸し九〇 結果を第３表に示す。最大延伸比とは延伸比を０．１ず
つ変更した時に、糸が全く延伸できなくなる寸前の延伸
比を示し、Ｉ！３表中の物性は最大延伸比における物性
である。The undrawn yarn package is slightly swollen, 530f/
At the same time, it was slightly swollen and some fuzz was seen here and there,
Since winding 9 was possible, the yarn pulled out from the 03 undrawn yarn packages that had been drawn under all conditions was doubled and drawn under the same conditions as Example 1.The results are shown in Table 3. . The maximum drawing ratio refers to the drawing ratio at which the yarn can no longer be drawn at all when the drawing ratio is changed by 0.1, and I! The physical properties in Table 3 are the physical properties at the maximum stretching ratio.

〈発明の効果〉 本発明に係るポリヘキサメチレンアジパミド高強力糸の
製造法を用いることにより、高速域での紡糸による高強
力糸を安定的に得ることができる０″１だ、設備も簡単
にな夛安価であシ、県立て作業も容易になる。<Effects of the Invention> By using the method for producing polyhexamethylene adipamide high strength yarn according to the present invention, high strength yarn can be stably obtained by spinning at a high speed. It is simple and inexpensive, and prefectural work becomes easier.

得られた高強力糸は、タイヤコードに加工され九段階に
おいて、低い中間伸度、乾熱収縮率全売し、耐疲労性も
従来のポリアミドタイヤコードに比べ数倍の性能を有す
るため、例えば、タイヤ製品の信頼性を向上させるなど
、新しい展開が期待できる。The obtained high-strength yarn is processed into tire cords and has low intermediate elongation, dry heat shrinkage rate, and fatigue resistance several times higher than that of conventional polyamide tire cords. We can expect new developments, such as improving the reliability of tire products.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明に係る巻取速度範囲であつて。 未延伸糸パッケージ形状を良好に保持できる範囲を示し
罠ものである。 Ｏ印はパッケージ形状良好 Ｘ印は側面はみ出しでパッケージ形状不良又は膨潤によ
る巻取不能FIG. 1 shows the winding speed range according to the present invention. This indicates the range in which the undrawn yarn package shape can be maintained well. O mark means the package shape is good.

Claims (1)

【特許請求の範囲】 １、実質的にポリヘキサメチレンアジパミドから成る繊
維を製造するに際し、蟻酸相対粘度が６０乃至９０のポ
リヘキサメチレンアジパミドの溶融物を、多数のノズル
を有する紡口から押出し、冷却域を通過させて後、紡口
から４ｍ以上下方で、紡糸油剤を付与して糸条を集束し
、引き取りロールを経ることなく、下記（１）式の条件
を満たす速度Ｗで直接に巻取機で巻取り、しかる後下記
（２）式の条件を満たす延伸比Ｄｒで延伸し、単糸繊度
が２．０乃至３．５デニールである延伸糸を得ることを
特徴とするポリヘキサメチレンアジパミド繊維の製造法
。 ５１００−３０ＶＲ≦Ｗ≦４７００−２０ＶＲ　（１）
式３．３０−（３／８０００）・Ｗ≦Ｄｒ　（２）式こ
こで、ＶＲはＡＳＴＭＤ−７８９に従って測定した蟻酸
相対粘度であり、Ｗは巻取速度（ｍ／分）であり、Ｄｒ
は延伸比（延伸後の弛緩率は含まない）である。Scope of the Claims 1. When producing fibers consisting essentially of polyhexamethylene adipamide, a melt of polyhexamethylene adipamide having a formic acid relative viscosity of 60 to 90 is passed through a spinning machine having a large number of nozzles. After extruding from the spout and passing through a cooling zone, a spinning oil is applied at least 4 m below the spinneret to collect the yarn, and the yarn is collected at a speed W that satisfies the condition of the following formula (1) without passing through a take-up roll. The yarn is directly wound with a winder, and then stretched at a stretching ratio Dr that satisfies the condition of formula (2) below to obtain a drawn yarn having a single yarn fineness of 2.0 to 3.5 deniers. A method for producing polyhexamethylene adipamide fiber. 5100-30VR≦W≦4700-20VR (1)
Equation 3.30-(3/8000)・W≦Dr (2) Equation where VR is the relative viscosity of formic acid measured according to ASTM D-789, W is the winding speed (m/min), and Dr
is the stretching ratio (not including the relaxation rate after stretching).