抗菌PTT POY的结构与性能研究

采用银系抗菌母粒与聚对苯二甲酸丙二醇酯(PTT)切片共混熔融纺丝,在一定纺丝速度下,通过改变泵供量,制备了不同线密度的抗菌PTT预取向丝(POY);研究了纤维的结晶、取向、物理性能和抗菌性能。结果表明:与未加抗菌母粒的PTT POY相比,对于相同规格的PTT POY,随抗菌母粒的加入,其初生纤维的结晶度降低,取向度略有上升,断裂强度和断裂伸长率有所下降,沸水收缩率变化不大;加入5%抗菌母粒的PTT POY对大肠杆菌和金黄色葡萄球菌具有良好的抑菌效果;随着喷丝头拉伸比的增加,抗菌PTT POY的取向度和结晶度相应增加,断裂伸长率降低,断裂强度增加,沸水收缩率有所下降。     

不同纺丝速度对涤纶混纤预取向丝结构及性能的影响

研究了在相同高速纺丝混纤异收缩一步法工艺和第二拉伸辊温度恒定的条件下,不同卷绕速度对用于制备涤纶混纤预取向丝的取向态结构、沸水收缩率以及力学性能的影响。实验结果表明,当卷绕速度由3 300 m/min提高到3 800 m/min时,涤纶预取向丝的取向因子和断裂强度随之增加,而断裂伸长率和沸水收缩率却随之减小。     

生物基聚酰胺510 POY纺丝成形工艺研究

以相对黏度2.5的生物基聚酰胺510(PA 510)为原料,通过高速纺丝制备PA 510预取向丝(POY),分析了PA 510的热性能,重点研究了PA 510切片干燥条件、纺丝温度、冷却条件、集束位置及卷绕速度对PA 510 POY纺丝成形稳定性的影响,并对PA 510 POY的力学性能进行表征。结果表明：PA 510的熔融峰值温度为217.3℃,PA 510的纺丝温度应高于218℃且低于其分解温度;在干燥温度80℃、干燥时间10 h的条件下,PA 510切片干燥后的含水率为265μg/g,满足纺丝工艺要求;控制纺丝温度252～254℃,侧吹风温度20℃、相对湿度大于等于85%、速度0.45 m/s,集束点距喷丝板距离900 mm,卷绕速度4 300 m/min,纺丝稳定,卷绕成形好,制得的88 dtex/24 f PA 510 POY的断裂强度4.21 cN/dtex、断裂伸长率64.45%、条干不匀率1.01%。     

八头纺生产125 dtex/36 f涤纶POY

将涤纶高速纺丝卷绕头由 4个丝筒改造为每个卷绕头同时卷出 8个丝筒 ,调整工艺参数 ,纺丝速度 3 2 5 0 m/ min,超喂率 10 .2 % ,侧吹风速度 0 .7m/ s,油嘴位置至下位 ,改造后 POY产量增加 1倍 ,POY条干不匀率下降到 1.4%～ 1.5 % ,丝筒成型良好 ,POY退绕能力也很好。     

170dtex/192 f直纺涤纶POY生产工艺探讨

采用特性粘数0.640-0.650 dL/g的PET熔体直接纺丝生产170 dtex/192f涤纶POY,使用熔体冷却器可有效控制输送过程中的熔体降解,选择纺丝温度290℃,侧吹风速度0.4 m/s,卷绕速度2 750 m/min, 适当控制其它条件,可得到涤纶POY的断裂强度2.29 cN/dtex,断裂伸长率128.2%,生产中毛丝量1.15%。     

PTT/PET并列型复合纺丝工艺研究

通过对并列型复合长丝纺丝原料的选择及特种纺丝组件的设计,探讨了PTT/PET并列型复合长丝的纺丝工艺。结果表明,选用特性黏度0.5~0.6 dL/g的PET与特性黏度1.2~1.3 dL/g的PTT以40/60~50/50（PET/PTT）的复合比,PET纺丝温度280~290℃,PTT纺丝温度255~270℃,复合纺丝速度2 500~3 000 m/min,可纺出性能良好的PTT/PET并列型复合长丝。     

聚丙烯高速纺丝工艺的研究——卷绕丝超分子结构与后加工性能的工艺控制

利用X射线衍射、DSC、双折射、密度梯度等方法探讨了在3km/min高纺速下,纺丝温度对丙纶POY的超分子结构与后加工性能的影响,对冷却条件的影响也进行了讨论。指出在280℃以下范围提高纺丝温度可以降低聚丙烯高速纺程上的流变张力,使卷绕丝的结晶度降低,结晶成分中次晶含量增加,非晶区取向度提高。采用缓慢冷却有和于提高POY的非晶区预取向。采用MI=35的聚丙烯树脂,在纺丝温度270℃和缓冷条件下可得具有优良后加工性能的丙纶POY,在414m/min速度下经加弹所得DTY的强度为41.1cN/t(?)x,伸长为34.1%,卷曲率为20%,卷曲稳定性为92%。     

拉伸工艺对PET/PTT复合纤维性能的影响

以310 dtex/48 f聚对苯二甲酸乙二醇酯(PET)/聚对苯二甲酸丙二醇酯(PTT)复合预向丝为原料,经拉伸后得到PET/PTT复合纤维,探讨了拉伸工艺对PET/PTT复合纤维力学性能和卷曲性能的影响。结果表明:在卷绕速度为500 m/min,拉伸温度160℃,热定型温度150℃的条件下,随着拉伸倍数的增加,PET/PTT复合纤维的断裂强度、沸水收缩率、卷曲收缩率明显提高,断裂伸长率呈下降趋势,卷曲稳定度变化不明显;拉伸温度和热定型温度对PET/PTT复合纤维力学性能和卷曲性能的影响相对较小;拉伸过程中,控制拉伸倍数为1.95～2.00,拉伸温度为140～160℃,热定型温度为130～170℃,PET/PTT复合纤维性能较好。     

PTT/PET自卷曲复合纤维的工艺性能

探讨了PTT/PET自卷曲复合纤维的生产工艺,研究结果表明:采用特性黏度为1.25 dL/g的PTT切片(纺丝温度275~280℃)、特性黏度为0.50 dL/g的PET切片(纺丝温度260~265℃),特制的并列型复合组件,在拉伸倍数2.85,卷绕角6.5°,卷绕张力0.16 c N/dtex,卷绕速度4100 m/min的条件下,可生产出质量稳定、性能较好的PTT/PET自卷曲复合纤维,并实现了批量化生产。     

熔体直纺288 dtex/288 f全消光扁平PET POY的生产工艺研究

将干燥的全消光母粒熔融挤出后与聚对苯二甲酸乙二醇酯(PET)熔体动态共混,采用熔体直纺工艺路线纺制288 dtex/288 f全消光扁平PET预取向丝(POY),研究了全消光母粒干燥工艺条件、螺杆温度、纺丝组件压力、纺丝温度、冷却条件、上油工艺和卷绕速度对纤维性能的影响。结果表明：较佳的生产工艺条件为在全消光母粒干燥温度140℃、干燥时间10 h,螺杆各区采用低温逐渐递增的排列形式,组件初始压力17.0 MPa,管道输送温度287.0℃,纺丝箱体温度292.5℃,冷却风压为35 Pa,无风区高度55 mm,集束位置900 mm,纤维上油率0.57%,卷绕速度2 530 m/min;在此工艺条件下,生产的288 dtex/288 f全消光扁平PET POY断裂强度为2.15 cN/dtex、断裂伸长率为130.5%、扁平度为3.2。     

PTT的纺丝稳定性和聚集态结构

利用毛细管流变仪研究PTT熔体挤出时的破裂现象,讨论PTT纺丝稳定性和初生纤维聚集态结构。结屎表明,PTT熔体是一种拉伸变稀型流体。自由挤出时,即使剪切速率达到1.5×105 s-1时,挤出熔体也没有出现明显的熔体破裂;而在纺丝过程中,在卷绕速度达到3.8 km／min(剪切速率2.1×103 s-1)时,就出现明显的熔体断裂现象。在高速纺丝中,控制PTT初生纤维取向结构的关键是喷丝头拉伸比,决定结晶结构的关键是卷绕速度。增加喷丝头拉伸比可以提高初生纤维的取向度;提高卷绕速度可以提高纤维结晶度。     

PET初生纤维在存放和热处理时结构和性能的变化

用声速法、密度和双折射法研究了PET的POY和LOY丝在存放和热处理中的变化。结果表明,用声速法可以跟踪卷绕所得初生纤维在早期结构重排产生的变化。取决于PET初生纤维在热处理前的双折射、热处理温度和热处理时间,可以观察到分子取向的弛豫或结晶,初生纤维具有完全不同的性能。     

Effects of spinning conditions on morphology and properties of polyethylene terephthalate fibers spun at high speeds

Fiber spinning of polyethylene terephthalate (PET) was studied at take-up speeds ranging from 2000 m/min to 7000 m/min under various spinning conditions. Effects of changes in process variables on the molecular orientation, crystallinity, and properties of as-spun PET fibers are reported. Conventional cross-flow quench in high-speed spinning yields fibers with undesirable crimp and asymmetric structure with respect to the fiber axis. Radial-flow quench eliminates these problems. Changes in other spinning conditions, such as extrusion temperature, throughput or take-up denier, and molecular weight, may also affect the development of PET fiber structure in the high-speed threadline.     

On-line studies of structure development during melt spinning of poly(butylene terephthalate)

An on-line study of structure development during poly(butylene terephthalate) melt spinning was carried out. Two polymers with different molecular weights (intrinsic viscosities of 0.75 and 1.0 dL/g) were used. The range of take-up velocities studied was 1500 to 4500 m/min. On-line measurements included diameter, temperature, birefringence, and tension. The phenomenon of diameter thinning (necking) was observed for both polymers at take-up velocities of 3500 and 4500 m/min with a mass throughput of 4 g/min. At a constant mass throughput, the distance from the spinneret at which the necking occurred varied with take-up velocity and molecular weight of the polymer. Increasing the take-up velocity at constant mass throughput caused an increase in cooling rate and a slight increase in the rate at which the temperature decreased with distance from teh spinneret. A small but detectable change in the rate of temperature decrease was observed at a position near or just beyond the formation of the neck. It is suggested that this effect is due to the increased heat transfer caused by the rapid increase in filament velocity and increased surface to volume ration in the neck. Increased take-up velocity also caused necking to occur at higher temperature, as did an increase of polymer molecular weight. Birefringence increased with distance from the spinneret and indicated substantial molecular orientation was developed in the filament prior to the necking zone. A sharp increase of birefringence in the necking zone was observed for take-up velocities of 3500 and 4500 m/min. A discussion of the mechanism of neck formation is presented, and it was concluded that necking is intimately associated with stress-induced crystallization in PBT. An increase of spinline stress resulting from either an increase of take-up velocity or an increase of molecular weight can cause stress-induced crystallization and, hence, necking to occur nearer the spinneret and at higher temperature. For a given polymer this leads to filaments with higher levels of crystallinity, crystalline orientation, and crystalline perfection (greater crystal size). These changes in morphology result in changes in the filament mechanical properties. The effect of molecular weight change on the structure and properties is complicated by the fact that the development of crystallinity seems to be affected by the molecular weight independent of the spinline stress.     

Melt spinning of nylon 6: Structure development and mechanical properties of as-spun filaments

The structure of melt-spun nylon 6 filaments was studied using on-line x-ray diffraction and birefringence measurements. Measurements were also made on as-spun and treated filaments. On-line wide-angle x-ray scattering measurements indicated that crystallization did not occur on the nylon 6 spinline at spinning rates up to 1000 m/min when spinning was done into either ambient air of 60% relative humidity or into wet saturated air. The filaments did crystalline gradually on the bobbin to a paracrystalline pseudohexagonal (γ) form. The rate of crystallization was dependent on the molecular orientation developed in the spun filaments. Crystalline orientation factors based on hexagonal symmetry were computed as a function of take-up velocity for fibers which were conditioned 24 hr in air at 65% relative humidity. Annealing in air or treatment in water or 20% formic acid solution causes a transformation from the pseudohexagonal form to the α monoclinic form. The tangent modulus of elasticity and tensile strength of spun and conditioned filaments increase with increasing take-up velocity and spinline stress, while elongation to break decreases with these variables.     

直接织造用120 dtex／96 f涤纶POY的生产工艺

采用半消光PET切片生产可直接用于织造的120 dtex／96 f涤纶POY．探讨了生产工艺对产品性能的影响。结果表明:采用直径0．22 mm喷丝孔,长径比4．3,控制组件压力12-13 MPa,熔体温度284- 287℃,侧吹风速度(0．35±0．03)m／s．卷绕速度3．10-3．12 km／min．生产的POY断裂强度2．0-2．1 cN／dtex,断裂伸长率115％-125％,条干不匀率小于1．58％。     

Structure and property studies of poly(trimethylene terephthalate) high-speed melt spun fibers

Poly(trimethylene terephthalate) has been melt spun at various take-up velocities from 0.5 to 8 km/min to prepare fiber samples. The effect of take-up velocity on the structure and properties of as-spun fibers has been characterized through measurements of birefringence, density, wide-angle X-ray scattering, DSC melting behavior, tensile properties and boiling water shrinkage (BWS). The birefringence exhibits a maximum at take-up velocities between 3 and 4 km/min. The fiber samples spun at the lower take-up speeds have essentially amorphous structures, while the filaments prepared at a velocity range higher than 4 km/min all possess an obvious crystalline structure. With increasing take-up speed, a steady improvement in tensile strength, elongation to break, and BWS is found, whereas the initial modulus remains almost constant within the measurement error, over the entire take-up speed range between 0.5 and 8 km/min.     

PET/PTT并列复合纤维生产工艺探讨

探讨了150 dtex/48 f聚对苯二甲酸乙二醇酯(PET)/聚对苯二甲酸丙二醇酯(PTT)双组分并列预取向丝(POY)的生产工艺.结果表明:选择特殊设计的纺丝组件,喷丝板的长径比大于2,孔形为花生形,选用特性黏数为0.53 dL/g的PET和特性黏数为1.02 dL/g的PTT切片质量比为50/50,PET的纺丝温...     

Fiber structure formation in ultra-high-speed melt spinning of poly(ethylene 2,6-naphthalene dicarboxylate)

The high-speed melt spinning of poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) was performed up to the take-up velocity of the ultra-high-speed region, 9 km/min. From the investigations of the structure and physical properties of the as-spun fibers, the high-speed spinning of PEN was divided into three regions in terms of the mechanism of fiber structure formation. The first region is the take-up velocity of up to 2.5 km/min and the birefringence of up to 0.08 where only a slight increase in molecular orientation was attained. At the take-up velocity of 2.5–4.5 km/min and the birefringence of 0.08–0.25, although some experimental evidences indicated that the orientation-induced crystallization did not occur, there was an increase in the fiber density which suggested the formation of some ordered structure. At the take-up velocity > 4.5 km/min and birefringence > 0.25, the orientation-induced crystallization occurred. The fibers obtained in this region were characterized by the formation of the crystalline structure dominated by the β form. The presence of the necklike deformation in the spinning line was also confirmed. The solidification temperature of the spinning line analyzed from the diameter profile suggested that the formation of β modification crystals occurred at relatively low crystallization temperatures in comparison with that in an isotropic state. Therefore it was indicated that the presence of elongational stress in the spinning line promoted the formation of the β modification crystals. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1415–1427, 1997     

Effect of zone drawing on the structure and properties of melt‐spun poly(trimethylene terephthalate) fiber

Melt‐spun poly(trimethylene terephthalate) (PTT) fibers were zone‐drawn and the structures and properties of the fibers were investigated in consideration of the spinning and zone‐drawing conditions. The draw ratio increased up to 4 with increasing drawing temperature to 180°C, at a maximum drawing stress of 220 MPa. Higher take‐up velocity gave lower drawability of the fiber. The PTT fiber taken up at 4000 rpm was hardly drawn, in spite of using maximum drawing stress, because a high degree of orientation had been achieved in the spinning procedure. However, an additional enhancement of birefringence was observed, indicating a further orientation of PTT molecules by zone drawing. The exotherm peak at 60°C disappeared and was shifted to a lower temperature with an increase in the take‐up velocity, which means that the orientation and crystallinity of the fiber increased. The d‐spacing of (002) plane increased with increasing take‐up velocity and draw ratio, whereas those of (010) and (001) planes decreased. In all cases, the crystal size increased with take‐up velocity and draw ratio. The cold‐drawn PTT fiber revealed a kink band structure, which disappeared as the drawing temperature was raised. The physical properties of zone‐drawn PTT fibers were improved as the draw ratio and take‐up velocity increased. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3471–3480, 2001