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聚乙交酯纤维纺丝工艺研究 总被引:2,自引:0,他引:2
采用改变纺丝速度、拉伸工艺以及测试纤维内应力、声速值、强度值等方法对聚乙交酯(PGA)的纺丝加工工艺及纤维的力学性能进行了分析研究。结果表明:纺丝速度对PGA初生纤维的取向度几乎没有影响,后拉伸能有效提高纤维的取向度及强度。低速纺丝得到的初生纤维内应力较小,可以进行高倍后拉伸,而高速纺丝得到的初生纤维内应力较大,只能进行低倍后拉伸。适当的加温以及低速拉伸有利于得到较高强度的PGA纤维。总体来说,要得到具有较好力学性能的PGA纤维,必须采用低速纺丝、高倍后拉伸、低速拉伸相加的工艺路线。 相似文献
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通过熔融纺丝工艺成功制备了超高分子量聚乙烯(UHMW-PE)/高密度聚乙烯(HDPE)共混初生丝,并将初生丝在不同温度下进行高倍率热拉伸制得UHMW-PE/HDPE共混纤维。采用广角X射线衍射(WAXD)、差示扫描量热(DSC)、拉伸试验等方法探讨了不同热拉伸温度下获得的UHMW-PE/HDPE共混纤维的微观结构及力学性能。结果表明,在85℃下拉伸所得的纤维具有最高的结晶度、结晶取向度以及最细长的晶粒形状,纤维的力学性能也最优。太低的拉伸温度不利于纤维的分子链以及晶体结构沿轴向取向,太高的拉伸温度则不利于纤维的晶体结构在拉伸过程中进行重组,因此太低或太高的拉伸温度均不利于纤维力学性能的提升。 相似文献
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PET连续纺丝拉伸的二种不同工艺:高速纺丝—低倍率高速拉伸;低速纺丝—高倍率高速拉伸。所得到的纤维都是FDY。比较了这二种工艺产品的性能和结构。并与普通的POY—DT及UDY—DT路线产品进行了对比。发现用高速纺丝低倍拉伸方法制得的纤维性质更好一些。而低速纺的方法实施起来更方便。在二种连续纺丝拉伸工艺中由于消除了"不同停留时间"的影响,其产品的染色均匀性都比间断的方法来得好。 相似文献
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超拉伸过程中UHMWPE纤维结构与性能的研究 总被引:1,自引:1,他引:0
利用密度梯度仪、声速取向仪、Instron材料强力仪、WAXD、DSC等手段 ,对超高相对分子质量聚乙烯 (UHMWPE)纤维在超拉伸过程中的结构和性能进行了测试研究。结果表明 ,不同拉伸倍数的UHMWPE纤维的结晶度、取向度、力学性能和熔融温度随着拉伸倍数的增大而增加 ;DSC图谱上的 Tm4 峰和WAXD分析证实了在超拉伸过程中UHMWPE纤维发生了正交晶相向六方晶相的转变 ,超拉伸后期结晶结构的变化对纤维的力学性能影响很大。 相似文献
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聚乳酸/聚乙醇酸复合纤维的性能探讨 总被引:3,自引:0,他引:3
对聚乳酸(PLLA)、聚乙醇酸(PGA)以复合比为85/15,70/30分别进行复合纺丝,制得两种皮芯复 合纤维,并对纤维的热性能、力学性能和结晶性能进行探讨。结果表明:PGA和PLLA在熔融纺丝时,没有发 生反应。纤维的强度随拉伸倍数的增加而增大,结晶度和取向度也都得到提高。复合纤维皮芯结合紧密,没 有裂隙和孔洞。 相似文献
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采用冻胶纺丝-超拉伸技术纺制了超高相对分子质量聚乙烯(UHMWPE)纤维。利用小角X光散射(SAXS)、广角X射线衍射(WAXD)及拉曼光谱等测试手段,研究了拉伸过程中UHMWPE纤维的结晶结构变化。结果表明:随拉伸的进行,纤维非晶区中分子链逐渐参与了结晶,纤维SAXS强度减弱,纤维结构变得紧密规整;纤维结晶长周期及结晶度随拉伸倍数的增加而增大,并趋于平衡,拉伸30倍后,纤维结晶长周期约为50 nm,结晶度约为67.5%;纤维横向晶粒平均尺寸随拉伸倍数的增加而变小,拉伸30倍后,趋于平衡,而纤维晶粒c轴方向的轴向晶粒尺寸随拉伸倍数的增加而变大。 相似文献
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聚醚醚酮纤维的拉伸定形后处理研究 总被引:2,自引:0,他引:2
通过熔融纺丝制得聚醚醚酮(PEEK)纤维,并采用差示扫描量热仪(DSC)、声速取向测量仪、热重分析仪、单纱电子强力仪分别研究了干热拉伸及热定形处理对PEEK纤维结晶和取向、热稳定性及力学性能的影响。结果表明:随着热拉伸倍数增大,PEEK纤维取向度、结晶度增加,纤维的断裂强度增加,断裂伸长减小;PEEK纤维的热拉伸温度应选在200~240℃,热定形温度应为220~260℃;PEEK纤维的重结晶主要是在热拉伸过程中完成,热定形则进一步完善纤维的结晶结构;经过后处理,PEEK纤维的断裂强度可达到6.12cN/dtex;且具有优异的热稳定性能,热分解温度高达505℃,后处理几乎不影响PEEK纤维的热稳定性。 相似文献
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Polyglycolic acid (PGA) fibers were prepared by melt‐spinning process in this report. The effects of spinning parameters, such as windup rates and drawn ratio, on the mechanical properties of the fibers were discussed by analyzing the internal stress of as‐spun fibers, axial sound velocity, fiber tenacity, etc. The results showed that windup rate had a slight effect on the macromolecular orientation degree of the as‐spun fibers, which was quite unusual for melt spinning, whereas, the subsequent drawing process effectively increased the macromolecular orientation degree of the PGA fibers and consequently increased the tensile strength of the fibers. Low internal stress of as‐spun fibers obtained at lower windup rate led to higher drawing ratio, and the drawn fibers possessed relatively excellent mechanical properties. As a contrast, higher windup rate resulted in the strong internal stress of the as‐spun fibers, which had a negative influence on the drawing process, and so the tensile strength of the drawn fibers was relatively poor. Therefore, PGA fiber with perfect mechanical performance could be prepared at the technical parameters of lower windup rate and higher drawing multiples as well as slow drawing rate. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
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将抗菌丙纶母粒(含质量分数20%无机载银抗菌粒子)与PP进行熔融共混、切片,再通过熔融纺丝制得抗菌丙纶。扫描电镜观察经表面改性处理的无机抗菌粒子在丙纶中分散较好,大小均匀,且与PP基体具有良好的界面相容性;DSC测试表明:抗菌粒子对PP基体有异相成核作用,使PP结晶度和熔融温度略有提高;加入无机抗菌粒子,降低了丙纶的力学性能,添加量宜1%;通过改变纤维的拉伸倍数,提高抗菌丙纶的力学性能,拉伸倍数为8时,其力学性能最好;该抗菌丙纶对革兰氏阴性和阳性菌的杀菌率都大于99.9%,经水洗后仍有较好的抑菌效果,具有一定的长效抗菌性。 相似文献
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PTT的纺丝稳定性和聚集态结构 总被引:1,自引:0,他引:1
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。 相似文献
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Won Seok Lyoo Hyun Seok Lee Byung Chul Ji Sung Soo Han Kang Koo Sam Soo Kim Joon Ho Kim Joon‐Seok Lee Tae Won Son Won Sik Yoon 《应用聚合物科学杂志》2001,81(14):3471-3480
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 相似文献