近年,ナイロン,ポリエステルの繊維分野では,DSDプロセス(Direct Spin Draw)が主流になる傾向がある.しかしPPの場合,DSDプロセスでは高延伸倍率が得られないために,低い破断強度の繊維しか得られない問題点があった.そこで,溶融紡糸直後に接触式の冷却引取りロールを設置し,延伸前の未延伸繊維を強制的に冷却してから延伸を行なう新しいDSDプロセス(I-DSD)を考案した.その結果,未延伸繊維の結晶化度を有効に制御でき,オンラインの延伸であるにもかかわらず,最大延伸倍率を9倍程度にまで高めることができた.オフライン延伸であるOffline Drawingプロセス(OFD)と同程度の高い延伸が可能となった.また,本プロセスで得られた未延伸繊維の結晶化度と最大延伸倍率の間には良い直線関係があり,未延伸繊維の結晶化度が低いほど高い最大延伸倍率に達することがわかった.

抄録全体を表示

溶融紡糸直後に接触式の冷却引取りロールを設置し,未延伸繊維の結晶化を制御して延伸を行なう新しいDSDプロセス(I-DSD)を考案した.前報では冷却引取りロールの設置による未延伸繊維の構造や延伸性に及ぼす影響について検討した.本報では,I-DSDプロセス,従来型のDSDプロセス(C-DSD),そして紡糸と延伸をオフラインで行うプロセス(OFD)の各プロセスで得られた繊維の構造を調べた.その結果,同じ延伸倍率で比較すると,C-DSDプロセスと他の2つのプロセスで得られた繊維の構造には大きな差があった.つまり,C-DSDプロセスの繊維は他のプロセスに比べて結晶化度,複屈折とも高かった.一方,繊維の融点は,OFDプロセスが最も高く,次にI-DSDプロセス,そしてC-DSDプロセスのものは最も低かった.この結果は長周期の傾向と一致し,繊維の融点が低いものほど長周期は小さかった.また,繊維の破断強度は,同じ延伸倍率で比べるとC-DSDプロセスの繊維が最も高かったものの,延伸倍率3～4倍程度にしか高められないために0.30GPa程度にとどまっていた.それに対して,I-DSDプロセスではOFDプロセスと同様に延伸倍率を9倍程度に高められるため,0.51GPa程度の高い破断強度の繊維が得られた.

抄録全体を表示

An uneven thickness distribution can cause serious problems in practical applications. In this report the deformation and thickness behavior of poly (ethylene terephthalate) (PET) film during transverse stretching in a tenter is discussed. The experiments were performed in a pilot plant with extrusion, casting, machine direction (MD) stretching, transverse direction (TD) stretching and thermosetting and winding processes. The thickness distribution of the PET film was measured after uniaxial orientation (MD stretched) and again after biaxial orientation (TD stretched in the tenter). The thickness behavior during the transverse stretching in the tenter was calculated by a finite element method (FEM), assuming a rigid-plastic or elastic-plastic constitutive law with parameters determined from the tensile stress-strain measurements. The tensile stress-strain tests were performed on MD stretched film in the transverse stretching direction. The FEM analysis was carried out using the measured initial thickness distribution of the uniaxially oriented film (MD stretched). It was estimated from this analysis that the (TD) stretching of the film in the tenter initiated near the tenter clip (edge of film), spread to the center of the film and then finally moved from the center to the edge of the film under the experimental conditions of this study. Good agreement was obtained between the experimental and predicted FEM results for the final film thickness distribution after transverse stretching.

抄録全体を表示

Superstructural changes during uniaxial deformation of Thermoplastic Polyester Elastomer (TPEE) films having different composition ratios of poly (butylene terephthalate) (PBT) and poly (tetramethylene glycol) (PTMG) were studied. Evaluations were done using polarizing microscope, small-angle light scattering (SALS), thermal analysis, dynamic mechanical measurement, tensile test and infrared spectroscopic analysis. It was found that the spherulitic superstructure existed in all samples, and the optical axis in the spherulite depended on the basic composition of TPEE. In the case of large PBT composition, the crystal transition from α-form to β-form occurred due to elongation. It was thought that this was caused by the transmittance of external force to the PBT crystallite. Furthermore, spherulites having large PBT composition were collapsed by elongation. Those with small PBT compositions showed the elastic recoverable property on cyclic deformation. It can be called as spherulite eastomer.

抄録全体を表示

The energy balance on the laser drawing process of poly (ethylene terephthalate) was analyzed by the on-line fiber temperature measurement. The energy converting process from the external work for drawing to the thermal energy was quantitatively investigated by comparing the measured temperature profiles with the estimated temperature profiles using energy balance equations. From the result, it was shown that 9-24% of the applied work was stored as the elastic energy into the system just after the neck drawing point, and that the stored elastic energy was released as the thermal energy with the progress of orientation-induced-crystallization. It was also shown that the ratio of stored energy to the applied work tend to increase with the increase of fiber speed.

抄録全体を表示