【０００１】
【発明の属する技術分野】
本発明は、二重らせん構造を有するコイル状構造糸及びその製造方法、並びにコイル状構造糸を使用した織編物に関するものである。
【０００２】
【従来の技術】
従来から、糸条に撚糸−熱セット−解撚を施して捲縮を付与し、織編物に嵩高性と伸縮性を発現させる仮撚加工は、熱セット性を有する合成繊維における差別化加工の代表的手法である。この仮撚加工を高度精密化した技術を用いて、いわゆる「新合繊」が誕生したのは周知である。この「新合繊」は、元来天然繊維を模倣することから始まったものだが、市場ニーズに次々と答えることで、この「新合繊」を使用した織編物の中には目標とする天然繊維織編物より高い質感と機能を持ち合わせる商品まで上市されるようになった。
しかしこの「新合繊」織編物も万能でなく、高い質感を追求すれば、糸加工から染色加工に至る全工程において高次加工が必要となり、天然繊維の質感と同格以上に仕上げると、かえってコスト高になる問題が生じ、用途が高級ゾーンに限られるなど問題もあった。
また、ここ数年は急速に人々の志向が多様化し、従来の「新合繊」では市場ニーズに応答できないケースが出始めてきた。
【０００３】
このような状況を反映し、「新合繊」織編物にはない質感を持つ多機能繊維の開発が切望され、我々は特に「新合繊」織編物が不得意とする伸縮性に着目して新たな繊維を開発した（例えば、非特許文献１参照）。この繊維は、二種のポリエステル系重合体をサイドバイサイド型に貼り合わせた構造を持つ潜在捲縮糸で、中〜強撚領域の加撚により、伸縮性、弾発性及びふくらみ感を織編物上で表現できる効果を奏す。この繊維からなる織編物は主にアウター、ボトム分野で注目され、さらに応用商品として、例えば上記潜在捲縮糸と自発伸長糸とを混繊処理して得られる加工糸で構成されたウール調織編物や、上記潜在捲縮糸と異型断面糸とを混繊処理して得られる加工糸で構成されたシルキー調織編物など、「新合繊」の技術思想を適用したことで、さらなる用途展開が可能となった。
一方で、「新合繊」がここしばらくの間市場の中心にあったことで、本来の素材（天然繊維）への回帰が見られ、天然繊維本来の質感と合成繊維の高い機能性を併せ持つ商品の開発が進められている。一例を示すと、天然繊維と合成繊維とを合撚又は混繊させた糸条を用いた長短繊維複合織編物がこれに該当する。
【０００４】
しかしながら、この長短繊維複合織編物は、織編物の表面に合成繊維が露出し、上記した「天然繊維への回帰」という要望に十分応答するに至っていない。
したがって、天然繊維の質感へ合成繊維の機能性を加味した織編物、すなわち天然繊維特有の質感であるナチュラル感、ソフト感及びふくらみ感を有する織編物でありながら、合成繊維の主要な機能性である伸縮性、弾発性を併せ持つ織編物の出現が求められている。
この要望に対し、一般的に実施されている方法は、弾性フィラメントの回りへ天然繊維をカバリングした糸条を製織編する方法である。しかしこのカバリング糸は、弾性フィラメントの伸縮性を生かすために、天然繊維の割合をあまり多くすることができず、織編物へソフト感を十分に付与できないという問題を有していた。そこで、天然繊維を弾性フィラメントの回りに緊密に配置する方法が提案されたが、得られたカバリング糸は、硬く緻密なため、依然として問題が残された。
これを解決するため、弾性フィラメントの回りへ天然繊維がカバリングされたカバリング糸と、別に用意された非弾性糸とが、該カバリング糸の撚方向と逆方向に特定の撚数で合撚されている複合糸が提案されている（例えば、特許文献１参照）。
この発明は、非弾性糸がカバリング糸の剛直さを低減させるという作用を利用したもので、織編物へ伸縮性とソフト感を付与できるのは勿論、非弾性糸がカバリング糸の伸縮性を適度に抑えるため、生折れやカーリングなども抑制できるという内容のものである。
【０００５】
一方、上記問題に対し我々は、合成繊維の加工糸を製造する技術思想でもって糸条を作製し、織編物へ伸縮性及び弾発性を発現させた。すなわち、合成繊維と天然繊維の芯鞘構造紡績糸を仮撚し、さらに得られた仮撚糸へ熱水処理を施すことで、織編物へ嵩高性、伸縮性及び弾発性を表現できる伸縮性紡績糸を提案した（例えば、特許文献２参照）。
この伸縮性紡績糸は鞘部に天然繊維が配されていることから、織編物へソフト感、ナチュラル感、仕立て映えの他、吸湿性などの機能性を付与することができる。
【０００６】
【非特許文献１】
繊維学会誌（繊維と工業）Ｖｏｌ．５８（２００２）Ｐ２２０〜２２３
【特許文献１】
特許２７６９０８０号公報（請求項１、〔０００５〕、〔００３７〕）
【特許文献２】
特許３０８１９７１号公報（請求項１、〔００１４〕、〔００１７〕）
【０００７】
【発明が解決しようとする課題】
しかし、上記特許文献１にかかる発明は、カバリング糸を合撚するため、該カバリング糸のトルクが影響し、合撚条件が厳格な上、品位が安定しないという問題を残している。
そして、特許文献２にかかる発明は、製織編前に紡績糸が熱水処理という熱履歴を受けている。したがって、リラックス工程で織編物へ伸縮性を付与する効果が乏しく、その結果、織編物の密度を甘めにしなければならないという設計上の制約を受けることとなり、商品バリエーションに限りがあるという問題を残している。
本発明は、この様な現状に鑑みて行われたものであり、天然繊維特有の質感であるナチュラル感、ソフト感及びふくらみ感を有する織編物でありながら、合成繊維の主要な機能性である伸縮性、弾発性を併せ持つ高品位な伸縮性織編物を製造しうる伸縮性紡績糸の提供を技術的課題とする。
【０００８】
【課題を解決するための手段】
本発明者らは、天然繊維及び／又は再生繊維を含有する短繊維が鞘部に配され、合成繊維が芯部に配された複重層紡績糸において、従来の技術思想から脱却し、該複重層紡績糸の持つ特異的性質に着目した結果、双糸によって長手方向に二重らせん構造を形成することで上記問題点を解決できることを見出した。
すなわち、本発明は次の（１）〜（９）を要旨とするものである。
（１）天然繊維及び／又は再生繊維を含有する短繊維が鞘部に配され、かつ合成繊維が芯部に配された複重層紡績糸からなり、該複重層紡績糸の双糸が長手方向に二重らせん構造を有するコイル状構造糸であることを特徴とする伸縮性紡績糸。
（２）前記複重層紡績糸の撚係数Ｋが３．０〜６．５であることを特徴とする（１）記載の伸縮性紡績糸。
ただし、Ｋ＝Ｔ／Ｓ１／２ ここで、Ｋ：撚係数 Ｓ：複重層紡績糸番手 Ｔ：１インチ間の撚数
（３）前記合成繊維が、極限粘度の異なる少なくとも二種類のポリエステル系重合体をサイドバイサイド型あるいは偏心芯鞘型に接合した潜在捲縮性複合繊維であることを特徴とする（１）又は（２）記載の伸縮性紡績糸。
（４）前記複重層紡績糸中に占める前記合成繊維の質量割合が１５〜６０質量％であることを特徴とする（１）〜（３）のいずれかに記載の伸縮性紡績糸。
（５）繊度が１０〜１２０番手であることを特徴とする（１）〜（４）のいずれかに記載の伸縮性紡績糸。
（６）前記複重層紡績糸を二本引き揃えて合糸し、撚係数Ｋ２．５〜９．０の加撚後、７０〜１３０℃で３０〜５０分の蒸気セットを施し、前記加撚と逆方向でかつ前記加撚と撚係数差１．３〜２．６を有する撚係数Ｋ１．１〜１０．０の解撚を施して捲縮発現させることを特徴とする（１）〜（５）のいずれかに記載の伸縮性紡績糸の製造方法。
ただし、Ｋ＝Ｔ／Ｓ１／２ ここで、Ｋ：撚係数 Ｓ：複重層紡績糸二本合糸の番手 Ｔ：１インチ間の撚数
（７）前記合成繊維が、弾性フィラメントであることを特徴とする（１）又は（２）記載の伸縮性紡績糸。
（８）前記弾性フィラメントの繊度が１０〜８０ｄｔｅｘであることを特徴とする（７）記載の伸縮性紡績糸。
（９）（１）〜（５）、（７）、（８）のいずれかに記載の伸縮性紡績糸を構成糸の２０質量％以上使用していることを特徴とする織編物。
【０００９】
以上の如く、本発明の伸縮性紡績糸は複重層紡績糸の双糸であって、二重らせん構造を有するコイル状構造を呈することで、二本の複重層紡績糸の間に空隙ができ、この空隙の存在が織編物における伸縮性、弾発性及びふくらみ感に深く関与する。
また、複重層紡績糸の撚係数が上がれば紡績糸の機械的強度は増すが、織編物に与えるソフト感は低減する。したがって、上記（２）の如く適度な撚係数を設定することで、互いの調和を保つことができる。
さらに、複重層紡績糸の芯部に配される合成繊維は、潜在捲縮性複合繊維であるのが望ましい。こうすることで、織編物へ新たにドレープ性を与えるだけでなく、弾発性とふくらみ感をさらに付与させることができる。
一方、織編物の伸縮性を特に向上させたい場合は、複重層紡績糸の芯部へ弾性フィラメントを配すれば該弾性フィラメントが具備する伸縮性と二重らせん構造が有するスプリング効果との相乗効果が生まれ、良好な伸縮性が発現する。
【００１０】
【発明の実施の形態】
以下、本発明を詳説する。
まず、複重層紡績糸の鞘部について説明する。
鞘部へは、天然繊維及び／又は再生繊維を含有する短繊維が配される。
本発明において天然繊維とは、綿、麻、絹、羊毛などを指し、再生繊維とは、ビスコースレーヨン、キュプラ、溶剤紡糸セルロース繊維などを指す。そして、これらの短繊維からなるステープルは繊度・平均繊維長共特に限定されない。
【００１１】
鞘部へは、上記で列挙した各種の天然繊維及び再生繊維の内、目的に応じて選択された一種以上の繊維と他糸とを複合した短繊維が配されてもよい。混合する他糸は、用途に応じ通常使用される短繊維であれば特に限定されない。例えばポリエステル、ポリアミド、アクリル、ポリウレタン、ポリオレフィンなどの合成繊維、トリアセテートなどの半合成繊維などがあげられる。混合する他糸が元来長繊維ならば、単糸繊度１〜３ｄｔｅｘのフィラメントを選び、平均繊維長３０〜６０ｍｍに切断してステープルにした上で使用する。これは、一般的に異種繊維を混合する場合、鞘部を構成するステープル間の均斉度を高くするには、繊度及び平均繊維長は混合相手に近づけるのがよいとされるため、３ｄｔｅｘより太くなれば、鞘部を構成するステープル全体が当該繊度となり、織編物にソフト感を付与するのが難しくなるので好ましくない。また、１ｄｔｅｘ未満では張り腰感を付与しづらくなるので好ましくない。
さらに、平均繊維長が６０ｍｍより長くなれば、鞘部を構成するステープル全体が当該平均繊維長となり、ステープル相互の重なり部分が大きくなる。よって、複重層紡績糸表面の毛羽が低減することから織編物へナチュラル感を付与するのが難しくなるので好ましくない。また、３０ｍｍ未満になるとステープル相互の重なり部分が小さくなり、可紡性の観点から必然的に複重層紡績糸が太くなり、薄地分野の織編物が作製できなくなるので好ましくない。
なお、フィラメント切断前にスタッフイングボックスを用いる機械捲縮付与、あるいは加熱処理による捲縮付与なども目的に応じて任意に行うこともできる。
【００１２】
一方、混合方法及び混合比率は特に限定されない。混合方法は、例えば混打綿工程でそれぞれの繊維原料を混ぜ合わせ、カード、練条、粗紡を経る方法、もしくはそれぞれの繊維原料を単独でカード工程まで紡績した後、練条工程にてスライバーで合せる方法、又はそれぞれの繊維原料を単独に練条し、複数のスライバーを引き揃えて粗紡する方法などがある。さらに、意匠性を向上したい場合は、光沢を有する繊維原料や既に染着された繊維原料などを使用する。例えば製造時に着色剤を混用して製造された原着糸又は先染糸からなる繊維原料、あるいは光沢の異なる異型断面糸又は艶消剤の含有量が異なる繊維などからなる繊維原料を適当量混ぜることで、仕上加工後に光沢や色相の異なる杢感を表現できる。
【００１３】
混合比率は、目的に応じ任意に決定してよいが、好ましくは、上記で列挙した各種の天然繊維及び再生繊維の内の少なくとも一種を、当該複重層紡績糸の鞘部に合計５０質量％以上含有させるのがよい。これは、コスト、可紡性に加え、用いられる繊維本来の特徴を生かすためで、５０質量％未満になると、当該織編物において、混合相手の繊維による干渉によって前記天然繊維又は再生繊維の風合いが低減される場合があり、好ましくない。
したがって、総合的に判断すれば、溶剤紡糸セルロース繊維（例えば「リヨセル（登録商標）」（レンチング社製）、「テンセル（登録商標）」（コートルズ社製）もしくは「モダール（登録商標）」（レンチング社製））、綿、あるいは羊毛のいずれかを単独で使用するのが特に望ましい。
単独使用することで、用いられる繊維本来の特徴が最大限生かされるため実用的でかつ用途展開が計りやすく、さらに、既存設備をそのまま使用するか又は若干の変更のみで製造可能であることから、コスト面でも優れるためである。
【００１４】
ただし、溶剤紡糸セルロース繊維及び綿のようなセルロース系繊維だけで鞘部を構成することは、織編物の吸水・吸湿性やソフト感、ふくらみ感をより向上させる効果を奏する一方、セルロース系繊維織編物特有の欠点を誘発する場合がある。すなわち、家庭洗濯時に湿潤状態で揉まれると当該セルロース系繊維織編物が摩擦を受け、ステープルが繊維軸方向に割繊し、フィブリル化が発生して織編物表面に毛羽が立つ欠点や、洗濯時のシワが通常の家庭乾燥では簡単に消滅しないといった欠点、あるいは、縫製時において、織編物の伸縮率変動により縫い糸との間に物理的糸長差が生じ、パッカリングを誘発するといった欠点などである。この場合、これらの欠点をなるべく抑えるために白化防止加工や形態安定加工を施すのが望ましい。
前記加工は公知法に準じて行えばよく、設備、効率などを考慮して、紡績工程中もしくは後述する伸縮性紡績糸とした後、あるいは製織編後の仕上加工工程中あるいは縫製商品とした後のいずれかでも行うことができる。一例を示すと、白化防止加工は、織編物に対し、エキソグルカナーゼ、エンドグルカナーゼ、セルビアーゼなどのセルロース分解酵素で処理した後、ポリウレタン樹脂含有水溶液に浸漬する。また形態安定加工は、仕上加工工程において撥水加工を施した後、ホルムアルデヒドによる気相加工を施す。
【００１５】
一方、鞘部を羊毛のみで構成した場合は、高級感があり仕立て映えに優れるなど感性面で秀でる効果を奏する。しかし、羊毛は家庭洗濯の際、大きく収縮しフェルト化する欠点があり、これを改善するため防縮加工を施すのが望ましい。該防縮加工も上述のセルロース系繊維と同様、紡績から縫製後に至るいずれかの段階で行われる。この防縮加工も公知法に準じて実施され、例えば、（１）羊毛繊維ステープルのスケールを次亜塩素酸ナトリウム、ジクロロイソシアヌール酸ナトリウムなどの塩素化剤あるいはモノ過硫酸、過マンガン酸カリウムなどの酸化剤で脱離させ、ポリアミドエピクロルヒドリン樹脂で被覆する方法、（２）羊毛繊維ステープルのスケールを合成高分子で被覆する方法、（３）低温プラズマ処理、コロナ放電処理などで繊維表面を改質することにより、羊毛繊維ステープルの摩擦係数の異方性を少なくする方法、があげられるが、操業性、コスト、防縮効果の調和を勘案して、紡績工程時の羊毛繊維スライバーへ（１）の方法を適用するのが望ましい。
【００１６】
次に、複重層紡績糸の芯部について説明する。
芯部へ配される繊維は、合成繊維であることが重要である。繊維形態は長・短繊維いずれでもよいが、ソフト感、嵩高性などの質感、吸水・吸湿性などの機能面を考慮し、短繊維が好ましく用いられる。繊維の種類は、熱セット性が良好であれば特に限定されないが、好ましくは通常のポリエステル又は通常のポリアミド、さらに好ましくは、極限粘度の異なる少なくとも二種類のポリエステル系重合体をサイドバイサイド型あるいは偏心芯鞘型に接合した潜在捲縮性複合繊維を用いるのがよい。該潜在捲縮性複合繊維を用いると織編物へ新たにドレープ性を与えるだけでなく、弾発性とふくらみ感をさらに向上させることができる。
芯部へ配される合成繊維が短繊維の場合は、例えば次のような方法により効率良く製造することができる。
ポリエステル重合体又はポリアミド重合体を複数の紡糸孔が穿設された紡糸口金から溶融紡糸し、紡出長繊維群を冷却した後引き取り、集束して１０万ｄｔｅｘ程度を超える未延伸トウとし、得られた未延伸トウを例えば複数段熱ローラ延伸装置を用い延伸して延伸トウとし、所定長に切断して短繊維とした後、混打綿、カード、練条を経てスライバーとする。このとき繊度・平均繊維長は任意に選択可能であるが、後に天然繊維や再生繊維と共に後述の伸縮性付与加工を施すので、均斉度の関係上、繊度１〜３ｄｔｅｘ、平均繊維長３０〜６０ｍｍが望ましい。
【００１７】
また、上記短繊維の断面形状は、何ら限定されるものでなく、丸型、楕円型、菱型、三角型、Ｔ字型、井型など任意の形状でよい。さらに該短繊維には、必要に応じて、例えば艶消剤、顔料、光安定剤、熱安定剤、酸化防止剤等の各種添加剤を本発明の効果を損なわない範囲内で添加することもできる。さらには、短繊維に切断する前にスタッフイングボックスを用いる機械捲縮付与、あるいは加熱処理による捲縮付与などを施してもよい。
【００１８】
一方、潜在捲縮性複合繊維の場合も、長・短繊維いずれでもよいが、上記と同様、短繊維が好ましく用いられる。潜在捲縮性複合繊維とは、極限粘度の異なる少なくとも二種類のポリエステル系重合体がサイドバイサイド型あるいは偏心芯鞘型に接合された断面形状を有する複合繊維の総称で、沸水による熱処理で優れた伸長率と弾性率を示す三次元スパイラル捲縮を発現する。つまり、高粘度ポリエステル系重合体が高収縮性を示し、低粘度ポリエステル系重合体が低収縮性を示すため、熱処理を施すことによって、両者間に収縮差が生じ、捲縮を発現すことができるのである。
本発明では、この内、極限粘度が異なる二種類のポリエステル系重合体をサイドバイサイド型に貼り合わせた断面形状を有する複合繊維が好ましく用いられる。ここでいう極限粘度は、フェノールと四塩化エタンとの等質量混合溶媒を用い、濃度０．５ｇ／１００、温度２０℃で測定した値から求めたものである。
該複合繊維を構成する極限粘度の異なる二種類のポリエステル系重合体としては、ポリエチレンテレフタレート（ＰＥＴ）やポリブチレンテレフタレートなどを採用することができるが、ＰＥＴ、もしくはエチレンテレフタレートを主たる繰り返し単位とする共重合体（以下、ＰＥＴ共重合体）が特に好ましい。また、本発明の効果を損なわない範囲で、必要に応じてイソフタル酸、２・２−ビス｛４−（β−ヒドロキシ）フェニル｝プロパンなどの共重合成分や、酸化チタンなどの艶消剤、ヒンダートフェノール系化合物などの酸化防止剤、顔料、難燃剤、抗菌剤、導電性付与剤、セラミックスなどの特性付与剤が適宜配合されていてもよい。高粘度及び低粘度成分の極限粘度は、それぞれ０．５５〜０．８０、０．５〜０．７５程度であればよい。
また、二種類のポリエステル系重合体の極限粘度差は、０．０１〜０．３であることが好ましい。０．０１未満では、上記潜在捲縮性複合繊維が十分な伸長率及び弾性率を発現せず、０．３を越える場合は、紡糸口金から吐出される重合体の流れが不規則となり、安定した紡糸が困難となる場合がある。
【００１９】
潜在捲縮性複合繊維を短繊維で用いる場合、１７０℃における自由収縮熱処理で５０個／２５ｍｍ以上のスパイラル捲縮（測定法はＪＩＳ−Ｌ１０１５−７−１２−１に準拠）を発現することが望ましい。スパイラル捲縮が５０個／２５ｍｍ未満の場合、織編物組織の拘束に打ち勝つだけの収縮応力が得られないため好ましくない。
また、カード工程でネップや未開繊部の発生しない原料とすることも必要である。一般にネップや未開繊部の発生は、捲縮数及び捲縮形態と密接な関係にあるので、８〜１８個／２５ｍｍの機械捲縮を付与した複合繊維を用いるのが望ましい。付与した機械捲縮数が８個／２５ｍｍ未満であると、未開繊部が発生しやすく、また１８個／２５ｍｍを超えるとネップが発生しやすい。
なお、機械捲縮を付与する手段としては、スタッフィングボックス、加熱ギヤなどが採用できるが、短繊維の場合には、一般にスタッフィングボックスが採用される。
本発明では、潜在捲縮性複合繊維を用いる場合でも、既述したように短繊維が好ましく用いられる。紡糸条件は、従来のポリエステル系潜在捲縮性複合繊維に準じ、既述したポリエステル系重合体又はポリアミド重合体の場合と同様、延伸トウの切断し、混打綿、カード、練条を経てスライバーとする。なお、機械捲縮付与は延伸トウの切断前に行われる。
ステープルの繊度・繊維長は任意に選択可能であるが、後に天然繊維や再生繊維と共に後述の伸縮性付与加工を施すので、均斉度の関係上、繊度１〜３ｄｔｅｘ、平均繊維長３０〜６０ｍｍが望ましい。
【００２０】
次に、合成繊維が芯部へ配され、天然繊維及び／又は再生繊維を含有する短繊維が鞘部へ配された複重層紡績糸の製法について説明する。
本発明に用いる複重層紡績糸は、前記二繊維が共に短繊維である場合、粗紡あるいは精紡工程で芯鞘構造とすることができ、芯部の合成繊維が長繊維である場合は、精紡工程で芯鞘構造とすることができる。
【００２１】
まず、芯・鞘部がいずれも短繊維の場合について説明する。
粗紡工程で芯鞘構造とする場合は、前記二繊維それぞれのスライバーを既述の方法で用意し、粗紡機により芯鞘構造の粗糸を作製した後、精紡する。すなわち、二繊維のスライバーを並列して粗紡機へ給糸する際、芯部をなす合成繊維（以下Ｒ１）のスライバーへ、天然繊維及び／又は再生繊維を含有する短繊維（以下Ｒ２）のスライバーを巻きつけるべく、Ｒ１スライバーをフライヤーヘッドより見てドラフト域の外側へ給糸し、Ｒ２スライバーを内側に給糸する。ドラフト域で所定の太さにドラフトされ、フロントローラーからそれぞれ繊維束として紡出される時、Ｒ１繊維束はドラフト軸（Ｒ１の糸道）方向の延長線と、フロントローラーのニップ点及びフライヤーヘッドとを結ぶ線とのなす角を、水平面に投影した角度２５〜６０°で好ましく紡出される。Ｒ２繊維束はそのまま直進し、Ｒ１繊維束及びＲ２繊維束は合糸されるが、ここでフライヤーの回転により生ずる撚りを、Ｒ１繊維束へ集中伝播させると共に、Ｒ２繊維束への撚りの伝播を皆無とさせることで、Ｒ１繊維束にＲ２繊維束をカバリング（芯鞘構造）することができる。簡単にいえば撚転作用を利用して芯鞘構造とする。ここで上記角度が２５°未満であると被覆繊維束（Ｒ２）のコイルピッチが長すぎて芯部（Ｒ１）が外部へ露出しやすくなる。また６０°を超えると、被覆繊維束（Ｒ２）のコイルピッチが短すぎて、被覆繊維束に重なりが生じ、粗糸に太さ斑が発生やすくなる。さらに、Ｒ１繊維束へＲ２繊維束が完全に捲き付くためには、Ｒ１繊維束はＲ２繊維束より紡出張力が高いことが重要である。これはフライヤーヘッドから生じる撚転作用でＲ１繊維束へＲ２繊維束が捲き付くが、Ｒ１繊維束とＲ２繊維束の紡出張力が同じなら合撚（交撚）糸状に、またＲ１繊維束の紡出張力がＲ２繊維束より小さければ芯と鞘が逆転することになる。紡出張力に差を付けるには紡出時、Ｒ１繊維束をＲ２繊維束より低フィードとすればよい。それにはフロントボトムローラーの径に差を付ければよく、径の小さい側へＲ１繊維束を、大きい側へＲ２繊維束を給糸する。
かくして、芯鞘構造の繊維束はフライヤーを通過して粗糸として巻き取られ、得られた粗糸は公知の方法で精紡され、本発明に用いる複重層紡績糸となる。
【００２２】
一方、精紡工程で芯鞘構造とする場合もその原理は粗紡の場合と同じである。二本それぞれの粗糸を公知の方法で用意し、リング精紡機で精紡し複重層紡績糸となる。精紡機へ二本の粗糸を給糸する際、トランペットを介して並列に給糸された該二粗糸は、バックローラー、セカンドローラーと順次送られながらドラフトされ、径の異なるフロントローラーへ並列に給糸され、それぞれ繊維束となる。この時、径の小さなローラーへはＲ１の繊維束を、大きなローラーへは、Ｒ２の繊維束を給糸することで、二本の繊維束間に物理的な糸長差（Ｒ１：短糸長、Ｒ２：長糸長）が生じる。フロントローラーの出口付近で、撚転作用により必然的に芯にはＲ１繊維束、鞘にはＲ２繊維束が配された二層繊維束が形成され、該二層繊維束はリング・トラベラーによる加撚並びにバルーン張力による緩み・斑の均斉化作用を受け、本発明に用いる複重層紡績糸となる。
【００２３】
本発明に用いる複重層紡績糸の作製に当たっては、上記粗紡又は精紡の内、粗紡による製法を採用するのが望ましい。これは、精紡による製法では、ドラフト工程で芯部の繊維束及び鞘部の繊維束は、それぞれが個別に繊維束表面においてステープルがマイグレーションより絡み合うため、芯・鞘部の臨界面ですべりが生じやすく、擦れなどの外力で、芯・鞘部が分離する場合がある。また同方法は合糸（カバリング）の際の緩み、ムラを解消するため、比較的強い撚りを施さなければならず、織編物のソフト感が欠けることがある。
対して、粗紡による方法は多少カバリングで緩み・ムラが存在しても、通常の精紡糸と同程度の撚りで十分にそれらを吸収・均斉化することができ、織編物のソフト感を保持することができるので好ましい。
【００２４】
次に、芯部の合成繊維が長繊維である複重層紡績糸の製法について説明する。この場合、既述の如く精紡工程で芯鞘構造とする。Ｒ２の粗糸のみトランペットを介してバックローラー、セカンドローラーと順次送られ、フロントローラーへ繊維束として給糸される。
一方、芯部を形成するＲ１の糸条は、テンサーで適度な張力をかけられ、ガイドを通じてフロントローラーへ給糸される。フロントローラーでは、張力の高いＲ１の糸条へ張力の低いＲ２の繊維束が重なることで芯鞘構造が形成され、リング・トラベラーによる加撚により複重層紡績糸となる。
【００２５】
ここで、以上述べた複重層紡績糸における撚係数及び芯・鞘部の質量割合について説明する。
まず、該複重層紡績糸の精紡工程における好ましい撚係数範囲（Ｋ＝Ｔ／Ｓ１／２ ただし、Ｋ：撚係数 Ｓ：複重層紡績糸番手 Ｔ：１インチ間の撚数）は、３．０〜６．５であり、さらに好ましくは３．４〜５．７である。撚係数が３．０より小さいと該複重層紡績糸を構成するステープル間に滑脱現象や織編物にした際ピリングが発生しやすくなる。逆に６．５より大きいと、該複重層紡績糸が緻密になるため、吸水・吸湿性が低下し、かつトルクも大きくなり製織編性に支障をきたす危険がある。
【００２６】
一方、芯部を形成する合成繊維と鞘部を形成する短繊維の質量割合は、１５／８５〜６０／４０の範囲にあることが望ましい。これは、芯部の合成繊維の質量割合が１５％質量未満であると、鞘部の短繊維の構成ステープル本数が多くなり、ステープル同士の結束力が大きくなるため、最終的に得られる伸縮性紡績糸及び織編物の伸縮性能が低下する危険があり、逆に芯部の合成繊維の質量割合が６０質量％を超えると、短繊維による合成繊維の被覆が十分に行えず、複重層紡績糸の糸側面に芯部の合成繊維が露出する場合があり、織編物にしたときの風合いが損なわれる危険がある。
【００２７】
そして、本発明の伸縮性紡績糸は、上記した複重層紡績糸からなり、該複重層紡績糸の双糸が長手方向に二重らせん構造を有するコイル状構造糸を形成することで得ることができる。
図１に本発明の伸縮性紡績糸の一例として、側面写真（電子顕微鏡写真）を示す。この図の如く、前記複重層紡績糸が双糸となって伸縮性紡績糸を形成し、該伸縮性紡績糸は、二重らせん構造を有するコイル状構造を呈することで、二本の複重層紡績糸間に空隙ができ、この空隙が織編物に弾発性及びふくらみ感を与える。そして、伸縮性紡績糸は、あたかもバネの如く伸縮することが可能であって、織編物へ良好な伸縮性を付与するのである。
【００２８】
次に、本発明の伸縮性紡績糸の製法において、伸縮性を付与する方法について述べる。
本発明の伸縮性紡績糸は、二本の複重層紡績糸に対し、加撚−熱セット−解撚を連続して行うことで、芯部へ配された合成繊維に捲縮を与えることで得られる。一例を示すと、公知の合成繊維用仮撚加工機へ二本の上記複重層紡績糸を同時に供給し、仮撚施撚体によって加撚されながらヒータ（非接触）によって熱固定され、仮撚施撚体を通過した後、解撚され、デリベリローラを経て巻取ローラによってパッケージへ巻き取られる。
該仮撚施撚体はスピンドルピンの他、フリクションディスク、ベルトニップ、流体旋回装置など、前記複重層紡績糸に旋回力を付与できる仮撚施撚体であれば特に限定されるものではないが、風綿による品質及び効率低下を考慮すれば、流体旋回装置が好ましい。
【００２９】
本発明の伸縮性紡績糸は、二重らせん構造を有するコイル状構造をとることで、織編物へ優れた伸縮性、弾発性及びふくらみ感などの効果を付与することができるが、上述したような公知の合成繊維用仮撚加工機による加工では、この効果が発現されないことがある。通常、仮撚加工機においては加撚と解撚の撚数の絶対値が同じであり、解撚によりいったん二本の複重層紡績糸が並列に配置される。そして、この状態から二重らせん構造を形成するためには、二本の複重層紡績糸同士のトルクと捲縮発現が一致していることが望まれるからである。つまり複重層紡績糸の捲縮発現はコイル状で、二本の複重層紡績糸同士の捲縮のコイルピッチが一致し、かつ互いの位相がずれた状態でコイル同士が絡むことで良好な二重らせん構造が形成される。仮撚斑が発生すると良好な二重らせん構造が形成され難いので、上記の如く合成繊維用仮撚加工機を使用すると、複重層紡績糸の長手方向で二本のコイルピッチとトルクを一致させるための加工条件や捲縮発現に寄与する合成繊維の選定が非常に厳しくなり、推奨できる方法とはいい難いのである。
【００３０】
そこで確実に二重らせん構造を形成させるためには、加撚の撚係数と解撚の撚係数とに差を設け、二本の複重層紡績糸が絡んだままの状態でコイル状捲縮を発現させれば効果的である。具体的には、パーンワインダーなどで二本の複重層紡績糸を引き揃えて合糸し、ダブルツイスターなどの撚糸機で撚係数２．５〜９．０（Ｋ＝Ｔ／Ｓ１／２ ただし、Ｋ：撚係数 Ｓ：複重層紡績糸二本合糸の番手 Ｔ：１インチ間の撚数）の加撚後、７０〜１３０℃で３０〜５０分の蒸気セットを施し、その後、前記加撚と逆方向でかつ前記加撚と撚係数差１．３〜２．６を有する撚係数１．１〜１０．０の解撚を施して本発明の伸縮性紡績糸とするのが好ましい。
ここで最初の加撚が撚係数２．５〜９．０としたのは、撚係数が２．５未満ではコイルピッチが長くなり十分な伸縮性が得られず、９．０を超えるとコイルピッチが短くなり十分な空隙を形成しづらく、またビリを発生させる場合もあり好ましくないからである。特に好ましい撚係数範囲は、４．５〜８．５である。またセット温度を７０〜１３０℃としたのは、７０℃未満ではセット効果が不十分で、１３０℃より高いと、複重層紡績糸の鞘部を構成する短繊維の物性を低下させる懸念があるため、好ましくないからである。
解撚について撚係数１．１〜１０．０としたのは、撚係数が１．１未満の場合は、解撚効果が乏しいため十分な伸縮性が得られない。また撚係数が１０．０を超えると、撚糸条件が厳しくなり撚斑が発生しやすく好ましくないからである。さらに、撚係数差を１．３〜２．６としたのは、１．３未満もしくは２．６を超えると、二本の複重層紡績糸が絡んだままの状態で二複重層紡績糸間に空隙が形成されず、伸縮性が低下するので好ましくないからである。
なお、この撚係数差は、加撚の撚係数から解撚の撚係数を差し引いた値の絶対値であり、加撚の撚係数と解撚の撚係数の大小は、どちらでもよい。
【００３１】
以上のようにして得られる本発明の伸縮性紡績糸のトータル繊度は１０〜１２０番手であるのが望ましい。１０番手より太くなると汎用性に欠け、１２０番手より細くなると、強度及び伸縮発現能力が低下するので好ましくない。
【００３２】
本発明の伸縮性紡績糸は、その構成単位である複重層紡績糸において、加撚−熱セット−解撚の工程により、捲縮が付与されることは既に述べたが、必ずしもそれによらず、芯部へ弾性フィラメントを配することによっても、本発明の伸縮性紡績糸を得ることができる。この場合は、既述の精紡工程で複重層紡績糸に捲縮が付与され、二本の複重層紡績糸が撚り合わされることになる。この芯部へ弾性フィラメントを配した態様においては、二本の複重層紡績糸の二重らせん構造に起因するスプリング効果と該複重層紡績糸自体の伸縮性との相乗効果により特に伸縮性に優れたものとすることができる。
弾性フィラメントとしては、ポリエーテル系ポリウレタン弾性糸あるいはポリエステル系ポリウレタン弾性糸が好ましく、その繊度としては１０〜８０ｄｔｅｘが望ましい。１０ｄｔｅｘ未満では、伸縮性紡績糸に十分な伸縮性を付与することができず、逆に８０ｄｔｅｘを超えると、伸縮性は十分なものの、伸縮性紡績糸の二重らせん構造が緻密になりすぎて、織編物にソフト感を付与できなくなる。
【００３３】
前記弾性フィラメントを用いて本発明を構成する複重層紡績糸を得るには、既述した場合と同様、精紡工程にて複重層紡績糸を作製すればよい。ただし、弾性フィラメントは繊度が小さく高伸縮性のため高い張力を掛けることができないため、フロントローラーへ給糸する際、鞘部を構成する短繊維の中心部分へ該弾性フィラメントが配されるようガイド設定を行い、さらに操業性を考慮して２〜４倍に延伸しながら給糸することが好ましい。
得られた複重層紡績糸を二本引き揃えて合糸しながら合撚機へ仕掛ける、又は合糸後ダブルツイスターへ仕掛けることで撚係数１．８〜３．２（Ｋ＝Ｔ／Ｓ１／２ ただし、Ｋ：撚係数 Ｓ：複重層紡績糸二本合糸の番手 Ｔ：１インチ間の撚数）の撚りを施し、本発明の伸縮性紡績糸を得ることができる。
【００３４】
以上のようにして得られる本発明の伸縮性紡績糸を用いて本発明の織編物が製造されるが、用途・目的に応じ、単独での撚糸や空気混繊、あるいは二本撚り、三本撚りなどにした上で供されても何ら差し支えない。また組織・密度に関わる設計、並びに織編物となす際の準備及び製織編に関わる工程条件・機種は適宜選択することができる。具体的には織物の経糸準備は、ワーパー、サイジング、ビーミングを経る通常の工程が望ましく、本発明の伸縮性紡績糸を使用した撚糸または混繊による糸条の場合は部分整経でもよい。織機は風綿発生を考慮しレピア織機もしくはエアージェットルームが望ましい。編物の場合は、通常の短繊維編物に使用される機種で対応可能である。
織編設計上の好ましい態様として、織編物を構成する構成糸の２０質量％以上に、本発明の伸縮性紡績糸が使用される。これは２０質量％未満では、本発明の目的である効果が得がたいためである。
【００３５】
仕上加工工程は、一般の長繊維織編物の方法に準じて行えばよく、精練・漂白、リラックス、プレセット、染色、ファイナルセットと順次行えばよい。リラックス工程によって伸縮性紡績糸がさらに捲縮し、該伸縮性紡績糸に良好な二重らせん構造を有するコイル状構造が形成され、織編物の伸縮性が向上する。
仕上加工の内、染色加工は公知の設備を用いればよく、例えば液流染色機、気流染色機、ウインス、パドル染色機などが挙げられる。また織編物の構成繊維に応じて染料を選択すればよい。また、仕上加工中において、目的に応じ各種付帯加工も実施できる。既述の如く、構成糸にセルロース系繊維が含まれる場合は、白化防止加工や形態安定加工を、羊毛が含まれる場合は、防縮加工をそれぞれ行うことができる。
【００３６】
図２は、本発明の伸縮性紡績糸を緯糸に使用した織編物の緯糸断面を電子顕微鏡で撮影したものである。本発明の伸縮性紡績糸は、この写真の如く、二本の複重層紡績糸がその中心部に空隙を有するよう二重らせん状に配されて、双糸をなしているのがわかる。
【００３７】
【作用】
本発明の伸縮性紡績糸は、長手方向に二重らせん構造を有するコイル状構造糸であるため、構成糸である二本の複重層紡績糸間に空隙ができ、この空隙の存在が織編物における伸縮性、弾発性及びふくらみ感に深く関与する作用を奏する。また、伸縮性紡績糸を構成する複重層紡績糸に対し、適度な撚係数を設定することで紡績糸の機械的強度と織編物のソフト感の調和を保つことができる。
さらに、前記複重層紡績糸の芯部に配された合成繊維が、極限粘度の異なる少なくとも二種以上のポリエステル系重合体をサイドバイサイド型あるいは偏心芯鞘型に接合した潜在捲縮性複合繊維であると、織編物へより高い弾発性とふくらみ感と共に良好なドレープ性も付与される。
【００３８】
本発明の伸縮性紡績糸の好ましい製法の一例は、二本の複重層紡績糸に対し加撚−熱セット−解撚を連続して行う製法である。確実に二重らせん構造を形成させるためには、加撚の撚係数と解撚の撚係数とに差を設け、二複重層紡績糸が絡んだままの状態でコイル状捲縮を発現させれば、効果的に二重らせん構造を形成できる。
一方、前記複重層紡績糸の芯部へ弾性フィラメントを配すれば、伸縮性をさらに向上させることができる。つまり二本の複重層紡績糸が二重らせん構造を有しながらコイル状構造を形成するので、そのスプリング効果との相乗効果を生む。
【００３９】
【実施例】
次に、実施例に基づき本発明を具体的に説明するが、本発明は、これらの実施例によって何ら限定されるものではない。物性評価は以下の方法に準じて行った。
（１）伸長率
ＪＩＳ Ｌ１０９６ ８．１４．１ Ａ法（定速伸長法）に準じて、荷重を４．９Ｎ、９．８Ｎ、１４．７Ｎの３種にて、経緯それぞれ測定した。
（２）寸法変化率
ＪＩＳ Ｌ０２１７ 第２頁記載の家庭洗濯１０３法に準じて洗濯を行い、ライン乾燥の後、ＪＩＳ Ｌ１９０９ ６．１布地の場合に準じてマーキングを行い、経緯それぞれの寸法変化率を測定した。
（３）伸長回復率及び残留歪率
ＪＩＳ Ｌ１０９６ ８．１４．２ Ｂ−２法（定伸長法）に準じて緯方向のみ測定した。
（４）ピリング
ＪＩＳ Ｌ１０７６ ６．１ Ａ法（ＩＣＩ形試験機を用いる方法）に準じて測定した。
（５）織物評価
官能検査にて織物の弾発性、ふくらみ感、ナチュラル感及びソフト感を測定した。評価結果は、◎：非常に良好、○：良好、△：やや劣る、×：劣る、の四段階評価とした。
【００４０】
（実施例１）
二酸化チタンを２．０質量％含有したポリエチレンテレフタレート繊維を１５万デニールのトウに集束し、延伸後、機械捲縮を付与して単糸繊度が１．６７ｄｔｅｘのトウ（クリンプトウ）を得た。このクリンプトウにポリオキシエチレン系油剤を繊維に対して０．２２質量％になるよう付与し、３２ｍｍにカットした繊維を２５℃、相対湿度６５％ＲＨの条件下に一昼夜エージングして平衡水分になるようにした後、公知の混打綿、カード、練条の各工程を通過させスライバーを得た。
一方、綿１．３０ｄｔｅｘ×３８ｍｍを公知の混打綿、カード、コーマ、練条の各工程を通過させスライバーを得た。
次に、得られた二本のスライバーを粗紡機へ供給するに際し、芯部をなすスライバーにポリエステルを、鞘部をなすスライバーに綿が位置するよう、粗紡機のフライヤーヘッドから見て外側にポリエステルスライバー、内側に綿スライバーを配し、ポリエステルスライバー４０質量％、綿スライバー６０質量％の割合になるように太さを調整した。このようにして粗糸を得たのち、撚方向Ｚ、撚係数３．２で公知法に準じた精紡を行い、３０番手の複重層紡績糸を得た。
さらに、得られた複重層紡績糸をパーンワインダーにて二本引き揃えて合糸した。
続いて、ダブルツイスターでＺ方向に撚係数８．０の加撚後、１２０℃×４５分の蒸気セットを行い、パーンワインダーで巻き返した後、Ｓ方向に撚係数６．０の解撚を行い、１５番手（３０番手双糸）の本発明の伸縮性紡績糸を得た。
【００４１】
次に、経糸に綿３０番手双糸を用いワーパー、サイジング、ビーミングを経て経糸ビームを作製し、該ビームをエアージェットルームに仕掛けた。緯糸には上記で得られた本発明の伸縮性紡績糸を用い、密度８２×５４本／吋の３／１ツイル織物の生機を製織した。
続いて、得られた生機に９０℃×２０分の精練・漂白を行い、液流バッチ方式で１２０℃のリラックス処理、乾熱１９０℃のプレセット後、１１０℃の反応染料染色（綿糸染色）、１３０℃の分散染料染色（ポリエステル染色）の後、ファイナルセットを経て、密度１００×５５本／吋の本発明の織編物を得た。
【００４２】
（実施例２）
実施例１の伸縮性紡績糸において、加撚の撚係数を６．３、解撚の撚係数を８．３とする以外は実施例１と同一にして本発明の伸縮性紡績糸を得た。
続いて、実施例１の織編物の緯糸を該伸縮性紡績糸に変更する以外は実施例１と同一にして本発明の織編物を得た。
【００４３】
（実施例３）
ビスフェノールＡのエチレンオキシド付加物４モル％及びイソフタル酸３モル％を共重合させた極限粘度０．７０のＰＥＴ系共重合ポリエステルと、極限粘度０．６８のＰＥＴとを用い、複合質量比１：１で複合溶融紡糸装置にて、孔数３４４孔の丸断面口金孔から、紡糸温度２９０℃、紡糸速度１１５０ｍ／分、吐出量２０４ｇ／分でサイドバイサイド型未延伸糸を得た。この未延伸糸を、延伸倍率２．４倍、延伸温度７０℃で延伸し、１６０℃で緊張熱処理を行い、スタッフィングボックスで機械捲縮を付与した後、カットして２．２ｄｔｅｘ×５１ｍｍの潜在捲縮性複合繊維を得た。１７０℃における無荷重下熱処理時の発現捲縮数は、６２個／２５ｍｍであった。得られた潜在捲縮性複合繊維に対し通常の紡績工程である混打綿、カード、練条を経てスライバーを得た。
次に、この潜在捲縮性複合繊維のスライバーを芯部に配すること以外は実施例１の伸縮性紡績糸と同一にして本発明の伸縮性紡績糸を得た。
続いて、実施例１の生機の緯糸を前記伸縮性紡績糸に変更する以外は実施例１と同一の生機を得た。得られた生機へ実施例１の仕上加工条件と同一の加工を施して密度１０３×５６本／吋の本発明の織編物を得た。
【００４４】
（実施例４）
市販のポリウレタン弾性糸４４ｄｔｅｘ（東レ・デュポン（株）製「ＬＹＣＲＡ（登録商標）」）を３．５倍に延伸しながら、ガイドを通じてリング精紡機のフロントローラーへ給糸した。一方で公知法に準じて作製された溶剤紡糸セルロース繊維（レンチング社製「リヨセル（登録商標）」）の粗糸を、前記リング精紡機へ精紡条件を撚方向Ｚ、撚係数３．０に設定して、トランペットを介してバックローラー、セカンドローラー、フロントローラーへと順次送り、該フロントローラーの出口で上記ポリウレタン弾性糸を芯へ配し、溶剤紡糸セルロース繊維を鞘へ配した芯鞘構造を形成させ、６０番手の複重層紡績糸を得た。
得られた複重層紡績糸二本を合撚機にて、Ｓ方向に撚係数２．３で引き揃えて合糸しながら合撚し、３０番手（６０番手双糸）の本発明の伸縮性紡績糸を得た。
次に、経糸が市販のポリエステル加工糸１６７ｄｔｅｘ／４８ｆ、Ｚ３００Ｔ／Ｍであり、緯糸には上記で得た伸縮性紡績糸及び市販の綿３０番手単糸が１：１に配されたツイル組織の生機をレピア織機にて作製した。得られた生機の密度は、１２９×７２本／吋であった。
続いて、該生機に対し一般のポリウレタン弾性糸使いの織編物に適用される条件に準じて仕上加工し、密度１６９×７９本／吋の本発明の織編物を得た。
【００４５】
（比較例１）
実施例１の生機において、緯糸を通常市販されているポリエステル／綿複重層紡績糸３０番手双糸（大和紡績（株）製「セルピー（登録商標）」）へ変更する以外は実施例１と同一の生機を得た。得られた生機へ実施例１の仕上加工条件と同一の加工を施して密度９０×５２本／吋の織編物を得た。
【００４６】
以上、本発明の織編物並びに比較例１の織編物の物性を表１に示す。
【表１】
【００４７】
実施例１〜４の織編物は、表１のように、ふくらみ感や伸縮性などに優れ、ピリング、寸法安定性も問題ない範囲であり、衣料用途に好適に使用できるものであった。特に、実施例３は、伸縮性紡績糸を構成する綿複重層紡績糸において、芯部へ潜在捲縮性複合繊維が配されているため、弾発性が特に良好であり、また、実施例４は、伸縮性紡績糸を構成する綿複重層紡績糸において、芯部へ弾性フィラメントが配されているため、緯方向伸縮性が特に良好であった。
一方、比較例１は、緯糸が市販のポリエステル／綿複重層紡績糸であるので伸縮性、弾発性に乏しく、ふくらみ感に欠けるものであった。
【００４８】
【発明の効果】
本発明の伸縮性紡績糸は、長手方向に二重らせん構造を有するコイル状構造糸であるため、構成糸である二本の複重層紡績糸間に空隙ができ、この空隙の存在が織編物における伸縮性、弾発性及びふくらみ感に深く関与する。従来から存在する伸縮性能を有する紡績糸の双糸を使用した織編物に比べ、本発明の織編物は、伸縮性、弾発性及びふくらみ感は勿論、ナチュラル感やソフト感といった質感にも優れている。さらに、伸縮性紡績糸を構成する複重層紡績糸には、吸水・吸湿性に対しピリングといった撚状態でその性能が相反する傾向に向かう特性に対しても、いずれも低下させない調和のとれた撚りが施されているため着衣快適性は良好で、用途はボトム、アウター、ユニフォームなどの中肉厚地分野だけでなく、ブラウスなどの薄地分野でも十分にその効果を発揮することができる。
【００４９】
前記複重層紡績糸の芯部へ潜在捲縮性複合繊維を用いれば、上述の伸縮性、弾発性及びふくらみ感はさらに増し、ドレープ性も発現する。
さらに、弾性フィラメントを本発明の伸縮性紡績糸の構成糸に供すれば、さらに伸縮性を向上させることができる。従来の弾性フィラメントを用いてなる紡績糸織編物は、伸縮性のみ良好で風合いは硬く改善が望まれているが、本発明の伸縮性紡績糸を構成するに当たり、該弾性フィラメントを用いても、当該織編物は、ナチュラル感、ソフト感、ふくらみ感などを保持しており、本発明は従来の問題を解決できる優れた衣料素材を提供できる。
【図面の簡単な説明】
【図１】本発明の伸縮性紡績糸の一例を示す図面代用写真であり、側面を電子顕微鏡で撮影したものである。
【図２】本発明の伸縮性紡績糸使いの織編物の一例を示す図面代用写真であり、緯糸断面を電子顕微鏡で撮影したものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coiled structural yarn having a double helical structure, a method for producing the same, and a woven or knitted fabric using the coiled structural yarn.
[0002]
[Prior art]
Conventionally, false twisting, in which a yarn is subjected to twisting, heat setting, and untwisting to impart crimp and express bulkiness and elasticity in a woven or knitted fabric, is a process of differentiation in synthetic fibers having heat setting properties. This is a typical method. It is well known that a so-called "new synthetic fiber" was born using a technology that has made this false twist processing highly precise. This new synthetic fiber originally started from imitating natural fibers, but by responding to the needs of the market one after another, some of the woven and knitted fabrics using this new synthetic fiber have the target natural fiber weave. Products that have a higher texture and function than knitted fabrics are now on the market.
However, this "new synthetic fiber" woven or knitted fabric is not versatile, and if high quality is pursued, high-order processing is required in all processes from yarn processing to dyeing. However, there was a problem that the use was limited to the high-grade zone.
Also, in recent years, people's intentions have diversified rapidly, and there have been cases where conventional “Synthetic Fibers” cannot respond to market needs.
[0003]
Reflecting this situation, there is a long-awaited need for the development of multifunctional fibers with a texture not found in "Shin Synthetic" woven or knitted fabric. A novel fiber has been developed (for example, see Non-Patent Document 1). This fiber is a latent crimped yarn that has a structure in which two types of polyester polymers are bonded in a side-by-side type. By twisting in the medium to strong twist region, stretchability, elasticity, and swelling feel are obtained on the woven or knitted fabric. This has the effect that can be expressed with. Woven and knitted fabrics made of these fibers are attracting attention mainly in the outer and bottom fields, and as applied products, for example, wool-like woven fabrics composed of processed yarns obtained by blending the latently crimped yarns and spontaneously elongated yarns Further application developments have been made by applying the technical concept of `` Shin Synthetic '', such as knitted fabrics and silky-toned knitted fabrics composed of processed yarns obtained by blending the above-described latently crimped yarns and modified cross-section yarns. It has become possible.
On the other hand, since “Synthetic Fiber” has been at the center of the market for some time, a return to the original material (natural fiber) has been seen, and products that combine the natural texture of natural fiber with the high functionality of synthetic fiber Is being developed. As an example, a long-short fiber composite woven or knitted fabric using a yarn obtained by twisting or blending a natural fiber and a synthetic fiber corresponds to this.
[0004]
However, in the long-short fiber composite woven or knitted fabric, the synthetic fibers are exposed on the surface of the woven or knitted fabric, and have not sufficiently responded to the above-mentioned demand for “return to natural fibers”.
Therefore, a woven or knitted fabric in which the functionality of a synthetic fiber is added to the texture of a natural fiber, that is, a woven or knitted fabric having a natural feeling, a softness, and a swelling feeling unique to a natural fiber, but with the main functionality of the synthetic fiber The appearance of a woven or knitted fabric having both elasticity and elasticity has been demanded.
In response to this demand, a commonly practiced method is to weave and knit a yarn obtained by covering natural fibers around an elastic filament. However, in order to make use of the elasticity of the elastic filament, the covering yarn has a problem that the ratio of the natural fibers cannot be increased so much that a soft feeling cannot be sufficiently imparted to the woven or knitted fabric. Therefore, a method of closely arranging the natural fibers around the elastic filaments has been proposed, but the obtained covering yarn is still hard and dense, so that a problem still remains.
In order to solve this, a covering yarn in which natural fibers are covered around an elastic filament, and a non-elastic yarn prepared separately, are twisted with a specific number of twists in a direction opposite to the twisting direction of the covering yarn. Some composite yarns have been proposed (for example, see Patent Document 1).
The present invention utilizes the effect that the inelastic yarn reduces the rigidity of the covering yarn. Not only can the inelastic yarn impart elasticity and softness to the woven or knitted fabric, but the inelastic yarn moderately expands the elasticity of the covering yarn. The content is that it is possible to suppress raw breakage and curling.
[0005]
On the other hand, in order to solve the above problem, we have produced yarns based on the technical idea of producing processed yarns of synthetic fibers, and have made the woven and knitted fabric exhibit elasticity and elasticity. In other words, by twisting a core-sheath structure spun yarn of a synthetic fiber and a natural fiber, and then subjecting the obtained false twisted yarn to hot water treatment, stretchability that can express bulkiness, stretchability and elasticity to the woven or knitted fabric A spun yarn has been proposed (for example, see Patent Document 2).
Since the stretchable spun yarn has natural fibers disposed in the sheath, it can impart functions such as softness, natural feeling, tailoring, and moisture absorption to the woven or knitted fabric.
[0006]
[Non-patent document 1]
Journal of the Textile Society of Japan (Fiber and Industry) Vol. 58 (2002) P220-223
[Patent Document 1]
Japanese Patent No. 2769080 (Claim 1, [0005], [0037])
[Patent Document 2]
Japanese Patent No. 3081971 (Claims 1, [0014], [0017])
[0007]
[Problems to be solved by the invention]
However, in the invention according to Patent Document 1, since the covering yarn is twisted, the torque of the covering yarn is affected, and the twisting conditions are strict, and the quality remains unstable.
In the invention according to Patent Document 2, the spun yarn is subjected to a thermal history of hot water treatment before weaving and knitting. Therefore, the effect of imparting elasticity to the woven or knitted fabric in the relaxing process is poor, and as a result, there is a design constraint that the density of the woven or knitted fabric must be reduced, and the product variation is limited. Have left.
The present invention has been made in view of such a current situation, and while being a woven or knitted fabric having a natural feeling, a soft feeling and a swelling feeling, which are characteristics of natural fibers, it is a main function of synthetic fibers. An object of the present invention is to provide a stretchable spun yarn capable of producing a high-quality stretchable woven or knitted fabric having both stretchability and elasticity.
[0008]
[Means for Solving the Problems]
The present inventors have departed from the conventional technical idea of a double-layer spun yarn in which staple fibers containing natural fibers and / or regenerated fibers are disposed in a sheath portion and synthetic fibers are disposed in a core portion. As a result of paying attention to the specific properties of the multilayer spun yarn, it has been found that the above problem can be solved by forming a double helical structure in the longitudinal direction with the twin yarn.
That is, the present invention has the following (1) to (9).
(1) A double-layer spun yarn in which short fibers containing natural fibers and / or regenerated fibers are disposed in a sheath portion and synthetic fibers are disposed in a core portion, and the twin yarn of the double-layer spun yarn is in a longitudinal direction. A stretchable spun yarn characterized by having a coiled structure yarn having a double helical structure.
(2) The stretchable spun yarn according to (1), wherein the twist coefficient K of the double-layer spun yarn is 3.0 to 6.5.
Where K = T / S 1/2 Here, K: twist coefficient S: double-layer spun yarn count T: number of twists between 1 inch
(3) The synthetic fiber is a latently crimpable conjugate fiber in which at least two types of polyester polymers having different intrinsic viscosities are bonded in a side-by-side type or an eccentric core-sheath type. (1) or (2) ).
(4) The stretchable spun yarn according to any one of (1) to (3), wherein a mass ratio of the synthetic fiber in the double-layer spun yarn is 15 to 60% by mass.
(5) The stretchable spun yarn according to any one of (1) to (4), wherein the fineness is from 10 to 120.
(6) The double-layer spun yarn is drawn and aligned and twisted, and after twisting with a twist coefficient of K2.5 to 9.0, steam setting is performed at 70 to 130 ° C for 30 to 50 minutes, and the twisting is performed. (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (2) that the untwisting is performed. 5) The method for producing a stretchable spun yarn according to any one of 5).
Where K = T / S 1/2 Here, K: twist coefficient S: count of double-layer spun yarn two-ply yarn T: number of twists per inch
(7) The stretchable spun yarn according to (1) or (2), wherein the synthetic fiber is an elastic filament.
(8) The stretchable spun yarn according to (7), wherein the fineness of the elastic filament is 10 to 80 dtex.
(9) A woven or knitted fabric characterized in that the stretchable spun yarn according to any one of (1) to (5), (7), and (8) is used in an amount of 20% by mass or more of a constituent yarn.
[0009]
As described above, the stretchable spun yarn of the present invention is a twin yarn of a double-layer spun yarn, and exhibits a coil-like structure having a double helix structure, whereby a void is formed between two double-layer spun yarns. The presence of these voids is deeply involved in the stretchability, elasticity and swelling of the woven or knitted fabric.
In addition, if the twist coefficient of the multi-layer spun yarn is increased, the mechanical strength of the spun yarn is increased, but the soft feeling given to the woven or knitted fabric is reduced. Therefore, by setting an appropriate twist coefficient as in (2) above, mutual harmony can be maintained.
Further, it is desirable that the synthetic fiber disposed in the core of the double layer spun yarn is a latently crimpable conjugate fiber. By doing so, not only can the woven or knitted fabric be given a new drape property, but also a resilience and a swelling feeling can be further imparted.
On the other hand, when it is desired to particularly improve the stretchability of the woven or knitted fabric, if an elastic filament is disposed on the core of the double-layer spun yarn, the synergistic effect of the elasticity of the elastic filament and the spring effect of the double helical structure is obtained. And good stretchability is exhibited.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
First, the sheath portion of the multi-layer spun yarn will be described.
Short fibers containing natural fibers and / or regenerated fibers are disposed on the sheath.
In the present invention, the natural fiber refers to cotton, hemp, silk, wool and the like, and the regenerated fiber refers to viscose rayon, cupra, solvent-spun cellulose fiber, and the like. Staples made of these short fibers are not particularly limited in terms of both fineness and average fiber length.
[0011]
Short fibers obtained by combining one or more fibers selected from the above various natural fibers and regenerated fibers with other yarns and other yarns may be disposed on the sheath. The other yarn to be mixed is not particularly limited as long as it is a short fiber generally used depending on the application. For example, synthetic fibers such as polyester, polyamide, acrylic, polyurethane, and polyolefin, and semi-synthetic fibers such as triacetate can be used. If the other yarn to be mixed is originally a long fiber, a filament having a single yarn fineness of 1 to 3 dtex is selected, cut into an average fiber length of 30 to 60 mm, and staples before use. This is because, in general, when mixing different types of fibers, it is said that the fineness and the average fiber length should be closer to the mixing partner in order to increase the uniformity between the staples constituting the sheath, so that the thickness is larger than 3 dtex. If it is not, the entire staple constituting the sheath portion has the fineness, and it is difficult to impart a soft feeling to the woven or knitted fabric, which is not preferable. On the other hand, if it is less than 1 dtex, it is difficult to give a feeling of tightness, which is not preferable.
Further, when the average fiber length is longer than 60 mm, the entire staple constituting the sheath has the average fiber length, and the overlapping portion of the staples becomes large. Therefore, the fluff on the surface of the multi-layer spun yarn is reduced, and it is difficult to impart a natural feeling to the woven or knitted fabric. On the other hand, if it is less than 30 mm, the overlapping portion between the staples becomes small, and from the viewpoint of spinnability, the double-layer spun yarn becomes inevitably thick, making it impossible to produce a woven or knitted fabric in the field of thin fabrics.
Before the filament is cut, mechanical crimping using a stuffing box or crimping by heat treatment can be arbitrarily performed according to the purpose.
[0012]
On the other hand, the mixing method and the mixing ratio are not particularly limited. The mixing method is, for example, mixing each fiber raw material in a blended cotton process, a card, a drawing, a method of passing through roving, or spinning each fiber raw material alone to a carding process, and then using a sliver in the drawing process. There is a method of mixing, or a method in which each fiber material is independently drawn, and a plurality of slivers are aligned and roving is performed. Further, when it is desired to improve the design, a glossy fiber material or an already dyed fiber material is used. For example, an appropriate amount of a fiber material composed of a dyed yarn or a yarn-dyed yarn produced by mixing a colorant at the time of production, or a fiber material composed of a modified cross-section yarn having a different gloss or a fiber having a different matting agent content is mixed. This makes it possible to express a feeling of heather with different gloss and hue after finishing.
[0013]
The mixing ratio may be arbitrarily determined according to the purpose, but preferably, at least one of the various natural fibers and regenerated fibers listed above is added to the sheath of the double-layer spun yarn in a total of 50% by mass or more. It is good to contain. This is to take advantage of the inherent characteristics of the fiber used, in addition to cost and spinnability, and when the amount is less than 50% by mass, the texture of the natural fiber or the regenerated fiber is reduced in the woven or knitted fabric due to interference by the fiber of the mixing partner. It may be reduced, which is not preferable.
Therefore, when comprehensively judged, solvent-spun cellulose fibers (for example, "Lyocell (registered trademark)" (manufactured by Lenzing Co., Ltd.), "Tencel (registered trademark)" (manufactured by Coatles Co., Ltd.) or "Modal (registered trademark)" (lentenching) It is particularly desirable to use any of cotton, or wool alone.
By using it alone, it is practical and easy to develop applications because the inherent characteristics of the fiber used are maximized, and because it can be manufactured using existing equipment as it is or with only slight changes, This is because the cost is also excellent.
[0014]
However, forming the sheath portion only with the solvent-spun cellulose fiber and the cellulosic fiber such as cotton has the effect of further improving the water-absorbing and hygroscopic properties, the softness, and the swelling of the woven or knitted fabric, while the cellulose-based fiber woven fabric has an improved effect. In some cases, a knitted fabric-specific defect may be induced. That is, when rubbed in a wet state at home washing, the cellulosic fiber woven or knitted fabric is subjected to friction, the staple is split in the fiber axis direction, fibrillation occurs and fluffs are formed on the surface of the woven or knitted fabric, and during washing, The drawback is that the wrinkles do not disappear easily in ordinary home drying, or that the physical thread length difference from the sewing thread due to fluctuations in the expansion and contraction rate of the woven or knitted fabric during sewing induces puckering. is there. In this case, it is desirable to perform whitening prevention processing and form stabilization processing in order to suppress these defects as much as possible.
The processing may be performed according to a known method, and in consideration of equipment, efficiency, and the like, during the spinning process or after forming an elastic spun yarn described below, or during the finishing process after weaving or knitting, or after forming a sewn product. Can be performed in any of the above. As an example, in the whitening prevention treatment, a woven or knitted fabric is treated with a cellulose-decomposing enzyme such as exoglucanase, endoglucanase, or selbiase, and then immersed in an aqueous solution containing a polyurethane resin. In the form stabilization processing, a water repellent processing is performed in a finishing processing step, and then a gas phase processing using formaldehyde is performed.
[0015]
On the other hand, when the sheath is made of only wool, it has an effect of excelling in sensitivity, such as having a sense of quality and excellent tailoring. However, wool has a drawback that it shrinks greatly and becomes felt when washed at home, and it is desirable to apply shrink-proofing to improve this. The shrinkproofing is also performed at any stage from spinning to after sewing as in the case of the above-mentioned cellulosic fiber. This shrinkproofing is also carried out in accordance with a known method. For example, (1) a wool fiber staple is scaled by using a chlorinating agent such as sodium hypochlorite, sodium dichloroisocyanurate, monopersulfuric acid, potassium permanganate, etc. A method of desorbing with an oxidizing agent and coating with a polyamide epichlorohydrin resin, (2) a method of coating the scale of wool fiber staple with a synthetic polymer, (3) modifying the fiber surface by low-temperature plasma treatment, corona discharge treatment, etc. There is a method of reducing the anisotropy of the coefficient of friction of wool fiber staples by taking into account harmony of operability, cost and shrinkage effect. It is desirable to apply
[0016]
Next, the core portion of the multi-layer spun yarn will be described.
It is important that the fibers disposed in the core are synthetic fibers. The fiber form may be either long or short, but short fibers are preferably used in consideration of texture such as softness and bulkiness, and functional aspects such as water absorption and hygroscopicity. The type of fiber is not particularly limited as long as the heat setting property is good, but is preferably a normal polyester or a normal polyamide, and more preferably a side-by-side type or an eccentric core of at least two types of polyester polymers having different intrinsic viscosities. It is preferable to use a latently crimpable conjugate fiber bonded in a sheath shape. When the latently crimpable conjugate fiber is used, not only a new drape property can be imparted to the woven or knitted fabric, but also the resilience and swelling can be further improved.
When the synthetic fibers disposed on the core are short fibers, the fibers can be efficiently produced by, for example, the following method.
A polyester polymer or a polyamide polymer is melt-spun from a spinneret in which a plurality of spinning holes are perforated, and the spun filament group is cooled, taken up, bundled, and formed into an undrawn tow exceeding about 100,000 dtex. The obtained undrawn tow is drawn into a drawn tow by using, for example, a multi-stage hot roller drawing device, cut into a predetermined length into short fibers, and then slivered through mixed cotton, card, and drawing. At this time, the fineness / average fiber length can be arbitrarily selected, but since the later-described stretch imparting process is performed together with the natural fiber and the regenerated fiber, the fineness is 1 to 3 dtex and the average fiber length is 30 to 60 mm because of the degree of uniformity. Is desirable.
[0017]
The cross-sectional shape of the short fiber is not limited at all, and may be any shape such as a round shape, an elliptical shape, a diamond shape, a triangular shape, a T shape, and a well shape. Further, if necessary, various additives such as a matting agent, a pigment, a light stabilizer, a heat stabilizer, and an antioxidant may be added to the short fibers as long as the effects of the present invention are not impaired. it can. Further, prior to cutting into short fibers, mechanical crimping using a stuffing box or crimping by heat treatment may be performed.
[0018]
On the other hand, in the case of latently crimpable conjugate fibers, either long fibers or short fibers may be used, but short fibers are preferably used as described above. Latent crimpable conjugate fiber is a generic name for conjugate fibers that have a cross-sectional shape in which at least two types of polyester polymers having different intrinsic viscosities are joined in a side-by-side type or an eccentric core-sheath type. Develops a three-dimensional spiral crimp showing modulus and modulus. In other words, since the high-viscosity polyester-based polymer exhibits high shrinkage, and the low-viscosity polyester-based polymer exhibits low shrinkage, by performing the heat treatment, a difference in shrinkage is generated between the two, and crimping may occur. You can.
In the present invention, of these, a composite fiber having a cross-sectional shape in which two types of polyester polymers having different intrinsic viscosities are bonded in a side-by-side type is preferably used. The intrinsic viscosity here is determined from a value measured at a concentration of 0.5 g / 100 and a temperature of 20 ° C. using an equal mass mixed solvent of phenol and ethane tetrachloride.
Polyethylene terephthalate (PET), polybutylene terephthalate, or the like can be used as the two types of polyester polymers having different intrinsic viscosities constituting the conjugate fiber, and PET or ethylene terephthalate is mainly used as a repeating unit. A polymer (hereinafter, PET copolymer) is particularly preferred. Further, a copolymer component such as isophthalic acid and 2,2-bis {4- (β-hydroxy) phenyl} propane, a matting agent such as titanium oxide, and the like, as long as the effects of the present invention are not impaired. Antioxidants such as hindered phenol compounds, pigments, flame retardants, antibacterial agents, conductivity imparting agents, and property imparting agents such as ceramics may be appropriately blended. The limiting viscosities of the high viscosity component and the low viscosity component may be about 0.55 to 0.80 and about 0.5 to 0.75, respectively.
The difference in intrinsic viscosity between the two types of polyester polymers is preferably 0.01 to 0.3. If it is less than 0.01, the latently crimpable conjugate fiber does not exhibit sufficient elongation and modulus, and if it is more than 0.3, the flow of the polymer discharged from the spinneret becomes irregular and stable. Spinning may be difficult.
[0019]
When the latently crimpable conjugate fiber is used as a short fiber, a spiral crimp of 50 pieces / 25 mm or more (measurement method conforms to JIS-L1015-7-12-1) may be exhibited by free shrinkage heat treatment at 170 ° C. desirable. If the number of spiral crimps is less than 50/25 mm, it is not preferable because shrinkage stress sufficient to overcome the constraint of the woven or knitted fabric cannot be obtained.
It is also necessary to use a raw material that does not generate neps or unopened portions in the carding process. In general, the occurrence of a nep or an unspread portion is closely related to the number of crimps and the form of crimps. Therefore, it is desirable to use a composite fiber provided with a mechanical crimp of 8 to 18 pieces / 25 mm. If the number of applied mechanical crimps is less than 8/25 mm, an unspread portion tends to occur, and if it exceeds 18/25 mm, nep tends to occur.
As a means for imparting the mechanical crimp, a stuffing box, a heating gear, or the like can be employed. In the case of short fibers, a stuffing box is generally employed.
In the present invention, even when latently crimpable conjugate fibers are used, short fibers are preferably used as described above. The spinning conditions are the same as those of the polyester-based polymer or the polyamide polymer described above, in accordance with the conventional polyester-based latently crimpable conjugate fiber, and the drawn tow is cut, slivered through a blended cotton, a card, and a drawing. And The mechanical crimping is performed before cutting the stretched tow.
The fineness and fiber length of the staple can be arbitrarily selected, but since the later-described stretch imparting process is performed together with the natural fiber and the regenerated fiber, the fineness is 1 to 3 dtex and the average fiber length is 30 to 60 mm because of the uniformity. desirable.
[0020]
Next, a method for producing a multi-layer spun yarn in which synthetic fibers are disposed in a core portion and short fibers containing natural fibers and / or regenerated fibers are disposed in a sheath portion will be described.
When the two fibers are both short fibers, the double-layer spun yarn used in the present invention can have a core-sheath structure in a roving or spinning step. A core-sheath structure can be obtained in the spinning process.
[0021]
First, the case where both the core and the sheath are short fibers will be described.
When the core-sheath structure is used in the roving step, slivers of each of the two fibers are prepared by the above-described method, and a roving machine is used to produce a roving yarn having a core-sheath structure, followed by spinning. That is, when the two-fiber sliver is fed in parallel to the roving machine, the sliver of synthetic fibers (hereinafter, R1) forming a core and the sliver of short fibers (hereinafter, R2) containing natural fibers and / or regenerated fibers are used. , The R1 sliver is fed outside the draft area as viewed from the flyer head, and the R2 sliver is fed inside. When drafted to a predetermined thickness in the draft area and spun out from the front roller as a fiber bundle, the R1 fiber bundle is extended along the draft axis (the yarn path of R1), the nip point of the front roller and the flyer head. Is preferably spun out at an angle of 25 to 60 ° projected on a horizontal plane with the line connecting. The R2 fiber bundle goes straight as it is, and the R1 fiber bundle and the R2 fiber bundle are combined. Here, the twist generated by the rotation of the fryer is concentrated and propagated to the R1 fiber bundle, and the twist propagation to the R2 fiber bundle is performed. By omitting it completely, the R1 fiber bundle can be covered with the R2 fiber bundle (core-sheath structure). Briefly, a core-sheath structure is formed by utilizing the twisting action. If the angle is less than 25 °, the coil pitch of the coated fiber bundle (R2) is too long, and the core (R1) is easily exposed to the outside. On the other hand, when the angle exceeds 60 °, the coil pitch of the coated fiber bundle (R2) is too short, and the coated fiber bundle is overlapped, and unevenness in the thickness of the roving is likely to occur. Further, in order for the R2 fiber bundle to be completely wound around the R1 fiber bundle, it is important that the R1 fiber bundle has a higher spinning tension than the R2 fiber bundle. This is because the R2 fiber bundle is wound around the R1 fiber bundle by the twisting action generated from the fryer head. If the spinning tension of the R1 fiber bundle and the R2 fiber bundle is the same, the R1 fiber bundle is formed into a twisted (intertwisted) yarn and If the spinning tension is smaller than the R2 fiber bundle, the core and the sheath are reversed. To make the spinning tension different, the spinning of the R1 fiber bundle may be made lower than that of the R2 fiber bundle during spinning. For this purpose, the diameter of the front bottom roller may be differentiated, and the R1 fiber bundle is supplied to the smaller diameter side and the R2 fiber bundle is supplied to the larger diameter side.
Thus, the fiber bundle having a core-sheath structure passes through a fryer and is wound as a roving, and the obtained roving is spun by a known method to be a multi-layer spun yarn used in the present invention.
[0022]
On the other hand, the principle of the core-sheath structure in the spinning process is the same as that of the roving. Each of the two rovings is prepared by a known method and spun with a ring spinning machine to form a double-layer spun yarn. When two roving yarns are fed to a spinning machine, the two roving yarns fed in parallel via a trumpet are drafted while being sequentially sent to a back roller and a second roller, and are paralleled to front rollers having different diameters. And the fiber bundles are formed. At this time, the fiber bundle of R1 is supplied to the roller having a small diameter, and the fiber bundle of R2 is supplied to the large roller, so that a physical yarn length difference between the two fiber bundles (R1: short yarn length) , R2: long yarn length). Near the outlet of the front roller, a two-layer fiber bundle having an R1 fiber bundle on the core and an R2 fiber bundle on the sheath is inevitably formed by the twisting action, and the two-layer fiber bundle is added by a ring traveler. Due to the uniformizing action of loosening and spots due to twisting and balloon tension, the multilayer spun yarn used in the present invention is obtained.
[0023]
In producing the double-layer spun yarn used in the present invention, it is desirable to adopt a method of roving from among the above roving or fine spinning. This is because, in the spinning process, the core fiber bundle and the sheath fiber bundle are individually entangled by staples on the fiber bundle surface due to migration during the drafting process, so slippage occurs at the critical surface of the core / sheath. It is easy to occur and the core / sheath may be separated by external force such as rubbing. In addition, this method requires a relatively strong twist in order to eliminate loosening and unevenness at the time of tying (covering), and the woven or knitted fabric may lack a soft feeling.
On the other hand, the roving method can sufficiently absorb and equalize them with the same degree of twist as ordinary spinning yarn, even if looseness and unevenness are present due to covering, thus maintaining the softness of the woven or knitted fabric. It is preferable because it can be used.
[0024]
Next, a method for producing a double-layer spun yarn in which the synthetic fiber of the core is a long fiber will be described. In this case, the core-sheath structure is used in the spinning process as described above. Only the R2 roving is sequentially sent to the back roller and the second roller via the trumpet, and is fed to the front roller as a fiber bundle.
On the other hand, the thread of R1 forming the core is given an appropriate tension by a tensor, and is supplied to a front roller through a guide. In the front roller, a core-sheath structure is formed by overlapping a low-tension R2 fiber bundle with a high-tension R1 yarn, and a multi-layer spun yarn is formed by twisting with a ring traveler.
[0025]
Here, the twist coefficient and the mass ratio of the core / sheath portion in the above-described multi-layer spun yarn will be described.
First, a preferable twist coefficient range (K = T / S) in the spinning process of the double-layer spun yarn 1/2 However, K: twist coefficient S: double-layer spun yarn count T: number of twists between 1 inch) is 3.0 to 6.5, more preferably 3.4 to 5.7. When the twist coefficient is less than 3.0, slippage between staples constituting the double-layer spun yarn and pilling when woven or knitted are liable to occur. On the other hand, when it is larger than 6.5, the multi-layer spun yarn becomes dense, so that the water absorption / hygroscopicity is reduced and the torque is increased, which may impair the weaving and knitting properties.
[0026]
On the other hand, the mass ratio of the synthetic fiber forming the core portion and the short fiber forming the sheath portion is preferably in the range of 15/85 to 60/40. This is because if the mass ratio of the synthetic fibers in the core is less than 15% by mass, the number of staples constituting the short fibers in the sheath increases, and the binding force between the staples increases. There is a risk that the stretchability of the spun yarn and the woven or knitted fabric may be reduced. Conversely, if the mass ratio of the synthetic fibers in the core exceeds 60% by mass, the synthetic fibers cannot be sufficiently covered with the short fibers, and the double-layer spun yarns In some cases, the synthetic fiber of the core may be exposed on the yarn side surface, and there is a risk that the texture of the woven or knitted fabric may be impaired.
[0027]
The stretchable spun yarn of the present invention is composed of the above-described double-layer spun yarn, and can be obtained by forming a coil-shaped structural yarn having a double helical structure in the longitudinal direction of the twin yarn of the double-layer spun yarn. it can.
FIG. 1 shows a side view photograph (electron micrograph) as an example of the stretchable spun yarn of the present invention. As shown in this figure, the multi-layer spun yarn becomes a twin yarn to form an elastic spun yarn, and the elastic spun yarn has a coil-like structure having a double helix structure, so that two multi-layer spun yarns are formed. Voids are formed between the spun yarns, and these voids give the woven or knitted fabric resilience and swelling. The elastic spun yarn can expand and contract as if it were a spring, and imparts good elasticity to the woven or knitted fabric.
[0028]
Next, a method for imparting elasticity in the method for producing an elastic spun yarn of the present invention will be described.
The stretchable spun yarn of the present invention performs twisting, heat setting, and untwisting on two double-layer spun yarns continuously to give crimp to the synthetic fibers disposed on the core. can get. As an example, two above-mentioned double-layer spun yarns are simultaneously supplied to a known synthetic fiber false twisting machine, and are heat-set by a heater (non-contact) while being twisted by a false twisted twisted body, and false twisted. After passing through the twisted body, it is untwisted, passed through a delivery roller, and wound up into a package by a winding roller.
The twisted twisted body is not particularly limited as long as it is a false twisted twisted body that can impart a turning force to the double-layer spun yarn, such as a friction pin, a belt nip, and a fluid swirling device, in addition to the spindle pin. Considering the quality and efficiency reduction due to fly waste, the fluid swirling device is preferable.
[0029]
The stretchable spun yarn of the present invention has a coil-like structure having a double helical structure, which can impart effects such as excellent stretchability, elasticity, and swelling to the woven or knitted fabric. Such a known synthetic fiber false twisting machine may not exhibit this effect. Usually, in a false twisting machine, the absolute value of the number of twists in twisting and untwisting is the same, and two double-layer spun yarns are once arranged in parallel by untwisting. Then, in order to form a double helical structure from this state, it is desired that the torque and the crimp onset of the two double-layer spun yarns match each other. In other words, the crimping of the multilayered spun yarn is coil-like, and the coil pitch of the crimping between the two multilayered spun yarns is the same, and the coils are entangled in a state where their phases are shifted from each other. A heavy helical structure is formed. When false twist spots occur, it is difficult to form a good double helical structure, so using a synthetic fiber false twisting machine as described above, the two coil pitches and the torque match in the longitudinal direction of the multilayer spun yarn. The selection of synthetic fibers that contribute to the development of crimping conditions and the development of crimps becomes very strict, and it is difficult to say that this is a recommended method.
[0030]
Therefore, in order to surely form a double helix structure, a difference is made between the twisting coefficient of twisting and the twisting coefficient of untwisting, and the coiled crimp is formed while the two double-layer spun yarns remain entangled. It is effective if expressed. Specifically, two double-layer spun yarns are aligned and combined by a pat winder or the like, and twisted with a twisting machine such as a double twister. The twist coefficient is 2.5 to 9.0 (K = T / S). 1/2 However, after twisting of K: twist coefficient S: count of double-layer spun double yarn T: twist number between 1 inch), steam setting was performed at 70 to 130 ° C. for 30 to 50 minutes. It is preferable that the stretchable spun yarn of the present invention is formed by performing untwisting in a direction opposite to twisting and having a twist coefficient of 1.1 to 10.0 having a twist coefficient difference of 1.3 to 2.6 with the twisting. .
Here, the reason why the first twist is set to a twist coefficient of 2.5 to 9.0 is that if the twist coefficient is less than 2.5, the coil pitch becomes longer and sufficient elasticity cannot be obtained. This is because the pitch becomes short and it is difficult to form a sufficient space, and there is also a case where a wobble occurs, which is not preferable. A particularly preferred twist coefficient range is 4.5 to 8.5. The reason why the setting temperature is set to 70 to 130 ° C. is that if the temperature is lower than 70 ° C., the setting effect is insufficient, and if the temperature is higher than 130 ° C., there is a concern that the physical properties of the short fibers constituting the sheath portion of the multi-layer spun yarn may be reduced. This is not preferred.
The reason why the twist coefficient is set to 1.1 to 10.0 for untwisting is that when the twist coefficient is less than 1.1, sufficient stretching properties cannot be obtained because the untwisting effect is poor. On the other hand, if the twist coefficient exceeds 10.0, the twisting conditions become severe and twist spots tend to occur, which is not preferable. Further, the twist coefficient difference is set to 1.3 to 2.6. When the twist ratio is less than 1.3 or exceeds 2.6, the two multi-layer spun yarns remain entangled between the two multi-layer spun yarns. This is because voids are not formed in the resin and the elasticity is lowered.
The twist coefficient difference is an absolute value of a value obtained by subtracting the untwisting twist coefficient from the twisting twist coefficient, and the magnitude of the twisting twist coefficient and the untwisting twist coefficient may be either.
[0031]
The total fineness of the stretchable spun yarn of the present invention obtained as described above is desirably 10 to 120 count. If it is thicker than 10th, it lacks versatility, and if it is thinner than 120th, it is not preferable because strength and expansion / contraction ability are reduced.
[0032]
Although the stretchable spun yarn of the present invention has been described as being crimped by the twisting-heat setting-untwisting step in the double-layer spun yarn as a constituent unit thereof, it is not necessarily limited thereto, The elastic spun yarn of the present invention can also be obtained by disposing an elastic filament on the core. In this case, a crimp is given to the double-layer spun yarn in the spinning step described above, and the two double-layer spun yarns are twisted. In the embodiment in which the elastic filament is arranged on the core portion, the elasticity is particularly excellent due to the synergistic effect of the spring effect caused by the double helix structure of the two multilayer spun yarns and the elasticity of the multilayer spun yarn itself. It can be.
As the elastic filament, a polyether-based polyurethane elastic yarn or a polyester-based polyurethane elastic yarn is preferable, and the fineness thereof is desirably 10 to 80 dtex. If it is less than 10 dtex, sufficient elasticity cannot be imparted to the stretchable spun yarn. Conversely, if it exceeds 80 dtex, although the stretchability is sufficient, the double helical structure of the stretchable spun yarn becomes too dense. This makes it impossible to impart a soft feeling to the woven or knitted fabric.
[0033]
In order to obtain a multi-layer spun yarn constituting the present invention using the elastic filament, a multi-layer spun yarn may be produced in the spinning step, as in the case described above. However, since the elastic filament has a small fineness and cannot be applied with a high tension because of its high elasticity, when feeding the yarn to the front roller, a guide is provided so that the elastic filament is disposed at the center of the short fiber constituting the sheath. It is preferable to set the yarn and feed the yarn while stretching it 2 to 4 times in consideration of operability.
The obtained double-layer spun yarn is drawn into a twisting machine while being twined and twined, or set into a double twister after twining to obtain a twist coefficient of 1.8 to 3.2 (K = T / S). 1/2 However, the stretchable spun yarn of the present invention can be obtained by twisting (K: twist coefficient S: double-layer spun yarn two-ply yarn count T: twist number between 1 inch).
[0034]
The woven or knitted fabric of the present invention is produced using the stretchable spun yarn of the present invention obtained as described above. Depending on the use and purpose, a single twisted yarn or an air-mixed fiber, or a double twisted yarn or a triple twisted yarn is used. There is no problem if it is served after twisting. In addition, the design relating to the structure / density, and the preparation conditions for forming a woven or knitted product and the process conditions / models relating to the weaving / knitting can be appropriately selected. Specifically, the preparation of the warp of the woven fabric is desirably a normal process of passing through a warper, a sizing, and a beaming, and may be a partial warping in the case of a twisted yarn or a mixed fiber using the stretchable spun yarn of the present invention. As for the loom, a rapier loom or an air jet loom is preferable in consideration of the generation of fly wool. In the case of a knitted fabric, a model used for ordinary short fiber knitted fabric can be used.
In a preferred embodiment of the weaving and knitting design, the stretchable spun yarn of the present invention is used in 20% by mass or more of the constituent yarns constituting the woven or knitted fabric. This is because if the amount is less than 20% by mass, it is difficult to obtain the effects intended by the present invention.
[0035]
The finishing process may be performed according to the method of a general long-fiber woven or knitted fabric, and may be sequentially performed as scouring / bleaching, relaxing, presetting, dyeing, and final setting. The stretchable spun yarn is further crimped by the relaxing step, and a coiled structure having a favorable double helical structure is formed in the stretchable spun yarn, and the stretchability of the woven or knitted fabric is improved.
Among the finishing processes, the dyeing process may be performed using known equipment, and examples thereof include a liquid jet dyeing machine, an air jet dyeing machine, a wins and a paddle dyeing machine. The dye may be selected according to the constituent fibers of the woven or knitted fabric. Further, during the finishing process, various incidental processes can be performed according to the purpose. As described above, whitening prevention processing and form stabilization processing can be performed when the constituent yarn contains cellulosic fibers, and shrink-prevention processing can be performed when wool is included.
[0036]
FIG. 2 is a photograph of a weft cross section of a woven or knitted fabric using the stretchable spun yarn of the present invention as a weft, taken with an electron microscope. As shown in this photograph, the stretchable spun yarn of the present invention has two double-layered spun yarns arranged in a double helix so as to have a void at the center thereof, forming a twin yarn.
[0037]
[Action]
Since the stretchable spun yarn of the present invention is a coil-shaped structural yarn having a double helical structure in the longitudinal direction, a void is formed between two double-layer spun yarns that are constituent yarns, and the presence of this void is a woven or knitted fabric. It has an action that is deeply involved in the elasticity, elasticity and swelling of the skin. In addition, by setting an appropriate twist coefficient for the double-layer spun yarn constituting the stretchable spun yarn, it is possible to maintain harmony between the mechanical strength of the spun yarn and the softness of the woven or knitted fabric.
Further, the synthetic fiber disposed at the core of the double-layer spun yarn is a latent crimpable conjugate fiber obtained by joining at least two or more polyester polymers having different intrinsic viscosities in a side-by-side type or an eccentric core-sheath type. In addition, a good drapability is imparted to the woven or knitted fabric with higher elasticity and swelling.
[0038]
An example of a preferred method for producing the stretchable spun yarn of the present invention is a method in which twisting, heat setting, and untwisting are continuously performed on two double-layer spun yarns. To ensure the formation of a double helical structure, a difference is made between the twisting coefficient of twisting and the twisting coefficient of untwisting, and the coiled crimp is developed while the double-layer spun yarn remains entangled. Thus, a double helix structure can be effectively formed.
On the other hand, if an elastic filament is arranged on the core of the double-layer spun yarn, the stretchability can be further improved. That is, since the two double-layer spun yarns form a coiled structure while having a double helical structure, a synergistic effect with the spring effect is produced.
[0039]
【Example】
Next, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. Physical properties were evaluated according to the following methods.
(1) Elongation rate
According to JIS L1096 8.14.1 A method (constant speed elongation method), the load was measured by using three types of loads of 4.9 N, 9.8 N, and 14.7 N, respectively.
(2) Dimensional change rate
Washing was performed according to the home washing method 103 described in JIS L0217, page 2, and after line drying, marking was performed according to JIS L1909 6.1, and the dimensional change rate of each process was measured.
(3) Elongation recovery rate and residual strain rate
It was measured only in the weft direction according to JIS L1096 8.14.2 B-2 method (constant elongation method).
(4) Pilling
The measurement was carried out according to JIS L1076 6.1 Method A (method using an ICI type tester).
(5) Fabric evaluation
The elasticity, swelling, natural feeling and soft feeling of the fabric were measured by a sensory test. The evaluation results were evaluated on a four-point scale: ◎: very good, ：: good, Δ: slightly poor, ×: poor.
[0040]
(Example 1)
Polyethylene terephthalate fibers containing 2.0% by mass of titanium dioxide were bundled into a 150,000 denier tow, stretched and then mechanically crimped to obtain a tow (crimp tow) having a single fiber fineness of 1.67 dtex. A polyoxyethylene-based oil agent is applied to this crimp tow in an amount of 0.22% by mass with respect to the fiber, and the fiber cut to 32 mm is aged at 25 ° C. and 65% RH for 24 hours to obtain equilibrium moisture. After that, slivers were obtained by passing through the known blended cotton, card and drawing processes.
On the other hand, 1.30 dtex x 38 mm of cotton was passed through known blended cotton, card, comb, and drawing steps to obtain a sliver.
Next, when supplying the obtained two slivers to the roving machine, the polyester is applied to the sliver serving as the core and the polyester is outwardly viewed from the flyer head of the roving machine so that the cotton is located in the sliver serving as the sheath. A sliver and a cotton sliver were arranged on the inside, and the thickness was adjusted so that the ratio of the polyester sliver was 40% by mass and the cotton sliver was 60% by mass. After the roving was thus obtained, spinning was performed in a twisting direction Z and a twisting factor of 3.2 in accordance with a known method to obtain a 30-ply double-layer spun yarn.
Further, the obtained double-layered spun yarn was drawn and aligned by a pan winder to be plied.
Subsequently, after twisting with a twist coefficient of 8.0 in the Z direction with a double twister, performing steam setting at 120 ° C. for 45 minutes, rewinding with a pan winder, and untwisting with a twist coefficient of 6.0 in the S direction. Thus, the stretched spun yarn of the present invention having a count of 15 and a count of 30 (double yarn) was obtained.
[0041]
Next, a warp beam was produced through a warper, sizing, and beaming using a 30-count cotton double yarn as a warp, and the beam was set in an air jet loom. The stretchable spun yarn of the present invention obtained above was used as the weft, and a 3/1 twill woven fabric having a density of 82 × 54 yarns / inch was woven.
Subsequently, scouring and bleaching of the obtained greige fabric at 90 ° C. for 20 minutes is carried out, a relaxation treatment at 120 ° C. is performed by a liquid flow batch method, a dry heat is preset at 190 ° C., and a reactive dye dyeing at 110 ° C. (cotton yarn dyeing). After disperse dye dyeing (polyester dyeing) at 130 ° C., the woven and knitted fabric of the present invention having a density of 100 × 55 yarns / inch was obtained through a final set.
[0042]
(Example 2)
The stretchable spun yarn of the present invention was obtained in the same manner as in Example 1 except that the twisting coefficient of twisting was 6.3 and the twisting coefficient of untwisting was 8.3 in the stretchable spun yarn of Example 1. .
Subsequently, a woven or knitted fabric of the present invention was obtained in the same manner as in Example 1 except that the weft of the woven or knitted fabric of Example 1 was changed to the stretchable spun yarn.
[0043]
(Example 3)
Using a PET copolymer having an intrinsic viscosity of 0.70 obtained by copolymerizing 4 mol% of an ethylene oxide adduct of bisphenol A and 3 mol% of isophthalic acid with PET having an intrinsic viscosity of 0.68, a composite mass ratio of 1: 1. With a composite melt spinning apparatus, a side-by-side undrawn yarn was obtained from a round cross-section die having 344 holes at a spinning temperature of 290 ° C., a spinning speed of 1150 m / min, and a discharge rate of 204 g / min. This undrawn yarn is drawn at a draw ratio of 2.4 times at a drawing temperature of 70 ° C., subjected to a tension heat treatment at 160 ° C., subjected to mechanical crimping in a stuffing box, and then cut to give a latent of 2.2 dtex × 51 mm. A crimped conjugate fiber was obtained. The number of developed crimps at the time of heat treatment under no load at 170 ° C. was 62 pieces / 25 mm. A sliver was obtained from the obtained latently crimpable conjugate fiber through a blended cotton, a card, and a drawing which are ordinary spinning processes.
Next, the stretchable spun yarn of the present invention was obtained in the same manner as the stretchable spun yarn of Example 1 except that the sliver of the latently crimpable conjugate fiber was disposed on the core.
Subsequently, the same greige machine as in Example 1 was obtained except that the weft of the greige machine of Example 1 was changed to the elastic spun yarn. The obtained green fabric was subjected to the same processing as the finishing processing conditions of Example 1 to obtain a woven or knitted fabric of the present invention having a density of 103 × 56 / inch.
[0044]
(Example 4)
A commercially available polyurethane elastic yarn 44dtex ("LYCRA (registered trademark)" manufactured by Du Pont-Toray Co., Ltd.) was supplied to a front roller of a ring spinning machine through a guide while being stretched 3.5 times. On the other hand, a roving yarn of a solvent-spun cellulose fiber (“Lyocell (registered trademark)” manufactured by Lenzing Co., Ltd.) produced according to a known method was applied to the ring spinning machine under the spinning conditions of the twist direction Z and the twist coefficient of 3.0. After setting, a back roller, a second roller, and a front roller are sequentially sent through a trumpet, and the polyurethane elastic yarn is arranged on a core at an outlet of the front roller, and a solvent-spun cellulose fiber is arranged on a sheath. It was formed to obtain a double-layer spun yarn having a count of 60.
The obtained double-layer spun yarn is twisted with a twisting machine while being aligned and twisted in the S direction with a twist factor of 2.3, and the stretchability according to the present invention of 30-count (60-count twin) is obtained. A spun yarn was obtained.
Next, the warp is a commercially available polyester processed yarn 167 dtex / 48f, Z300 T / M, and the stretchable spun yarn obtained above and the commercially available cotton 30th single yarn are arranged in a 1: 1 weft as a weft. The greige was made with a rapier loom. The density of the obtained greige was 129 × 72 / inch.
Subsequently, the greige fabric was subjected to finish processing in accordance with the conditions applied to a general woven or knitted fabric using polyurethane elastic yarn, to obtain a woven or knitted fabric of the present invention having a density of 169 × 79 / inch.
[0045]
(Comparative Example 1)
In the greige machine of Example 1, the same as that of Example 1 except that the weft is changed to a commercially available polyester / cotton double-layer spun yarn 30th twin yarn (“Serpy (registered trademark)” manufactured by Daiwa Spinning Co., Ltd.) I got a greige. The obtained green fabric was subjected to the same processing as the finish processing conditions of Example 1 to obtain a woven / knitted fabric having a density of 90 × 52 yarns / inch.
[0046]
Table 1 shows the physical properties of the woven or knitted fabric of the present invention and the woven or knitted fabric of Comparative Example 1.
[Table 1]
[0047]
As shown in Table 1, the woven and knitted fabrics of Examples 1 to 4 were excellent in swelling feeling and elasticity, were in a range in which pilling and dimensional stability were not a problem, and could be suitably used for clothing. Particularly, in Example 3, since the latently crimpable conjugate fiber is disposed in the core of the cotton double-layer spun yarn constituting the stretchable spun yarn, the elasticity is particularly good. No. 4, in the cotton double-layer spun yarn constituting the stretchable spun yarn, the elastic filament was arranged on the core portion, so that the stretchability in the weft direction was particularly good.
On the other hand, in Comparative Example 1, since the weft was a commercially available polyester / cotton double-layer spun yarn, the weft was poor in elasticity and resilience and lacked swelling.
[0048]
【The invention's effect】
Since the stretchable spun yarn of the present invention is a coil-shaped structural yarn having a double helical structure in the longitudinal direction, a void is formed between two double-layer spun yarns that are constituent yarns, and the presence of this void is a woven or knitted fabric. Deeply related to the elasticity, elasticity and swelling of the skin. Compared to woven and knitted fabrics using the twin yarns of spun yarns that have stretch performance that exist in the past, the woven and knitted fabrics of the present invention are not only superior in texture, such as naturalness and softness, as well as elasticity, elasticity and swelling. ing. In addition, the multi-layer spun yarn that composes the stretchable spun yarn has a harmonious twist that does not reduce any of the characteristics that tend to contradict each other in the twisted state such as pilling for water absorption and moisture absorption. As a result, the clothing comfort is good, and the effect can be sufficiently exerted not only in the field of medium thick material such as bottoms, outerwear and uniforms but also in the field of thin materials such as blouses.
[0049]
When latently crimpable conjugate fibers are used for the core portion of the double-layer spun yarn, the above-mentioned stretchability, elasticity and swelling are further increased, and drape properties are also exhibited.
Furthermore, if the elastic filament is provided as a constituent yarn of the stretchable spun yarn of the present invention, the stretchability can be further improved. Spun yarn woven and knitted fabrics using conventional elastic filaments have good elasticity only, and the texture is hard and improvement is desired.However, in constituting the elastic spun yarn of the present invention, even if the elastic filaments are used, The woven or knitted fabric has a natural feeling, a soft feeling, a swelling feeling, and the like, and the present invention can provide an excellent clothing material that can solve the conventional problems.
[Brief description of the drawings]
FIG. 1 is a drawing substitute photograph showing an example of a stretchable spun yarn of the present invention, a side surface of which is photographed with an electron microscope.
FIG. 2 is a drawing substitute photograph showing an example of a woven or knitted fabric using stretchable spun yarn of the present invention, in which a cross section of a weft is photographed with an electron microscope.
