活化油剂及上油工艺对聚酯高强纤维性能影响

以普通高强型GHT、高模低缩型HMLS和高强超低缩型SLS涤纶工业丝为研究对象，研究了活化油剂上油及干燥条件对纤维力学、热性能的影响。结果表明：干燥处理(75℃)后涤纶工业丝的线密度和结晶度增大，而断裂强度、杨氏模量、热收缩性能、声速取向因子及声速模量出现不同程度的下降，断裂伸长率未有明显变化。上油处理后，涤纶工业丝的线密度增大，断裂强度、杨氏模量、热收缩率与热收缩力降低，而断裂伸长率和结晶度未有明显变化。GHT和HMLS涤纶工业丝上油处理后的声速取向因子和声速模量较原丝均有上升。对比其他两类工业丝，SLS涤纶工业丝经上油和干燥(75℃)后，力学强度和模量损失有限，热收缩率降低明显，尺寸稳定性好，结晶度增加，更适合用于涤纶工业丝的活化改性及应用。     

高收缩涤纶的热学性能分析

高收缩涤纶是经过物理或化学改性得到的具有高热收缩率的差别化纤维。热分析显示,高收缩涤纶的耐热性低于普通涤纶,热收缩性明显优于普通涤纶。未收缩的高收缩涤纶的强度低于普通涤纶;热水收缩后的高收缩涤纶的断裂强度有所下降,纤维断裂伸长率明显变大;干热收缩后,高收缩涤纶的断裂强度和断裂伸长率的变化与热水收缩后相似,但下降幅度增加,尤其是温度达到140℃时,纤维断裂强度和断裂伸长率均明显下降。     

热定形工艺对高强型聚酯工业丝结构性能的影响

为探究不同热定形温度获得的高强型聚酯工业丝性能差异的内在结构因素,对3种高强型聚酯工业丝的结构性能进行对比。采用小角X射线散射和广角X射线衍射方法对其多尺度微观结构进行研究,结合力学性能及热收缩等结果,明确不同热定形工艺对高强型工业丝结构性能的影响。结果表明：热定形温度主要影响聚酯工业丝非晶区取向和片晶结构;相比于高强中缩(HTMS)和高强(HT)聚酯工业丝,高强低伸型(HTLE)聚酯工业丝的热定形温度低,高倍牵伸产生的伸直非晶区分子链在较低热定形温度下并未及时排入晶格形成结晶,而发生了小幅的回复,导致HTLE聚酯工业丝表现出非晶区取向高、结晶度低、晶粒尺寸小与片层倾斜角较大的结构特点,从而使断裂伸长率最小、初始弹性模量最大、尺寸稳定性差。     

后加工中热处理张力变化对高模低收缩涤纶工业丝结构与性能影响

针对后加工热处理过程中高模低收缩型(HMLS)涤纶工业丝受热引起性能变化的问题,分别将HMLS涤纶工业丝置于150 ℃不同预加张力(0~0.10 cN/dtex)条件下热处理5 min,分析热处理前后样品的构象变化,阐明其性能调控的结构因素。结果表明:随着预加张力的减小,HMLS涤纶工业丝的断裂强度略有减小,初始模量和5%形变下的断裂强度明显降低,而断裂伸长率明显增大;热处理主要影响非晶区的结构变化,导致HMLS涤纶工业丝的非晶区取向变低、反式构象含量变小、片晶长周期变小以及非晶区厚度变小;可通过施加一定的预加张力有效抵消HMLS涤纶工业丝在后加工中受热时的收缩应力,从而降低非晶区分子链的运动能力,使得力学性能及非晶区结构变化幅度减小。     

工业用涤纶长丝的结构与性能

 采用显微照相系统、差热分析仪、纤维拉伸强力仪、纱线拉伸强力仪、热收缩仪等对3类工业用涤纶丝的形态结构、力学性能、热收缩性能等进行测试分析。结果表明：高强型(HT)涤纶丝单纤强度和复丝强度均大于高模低缩型(HMLS)和高强低缩型(LS)涤纶丝,断裂伸长最小,模量居中;高模低收缩型、高强低收缩型涤纶丝沸水收缩率和干热收缩率均低于高强型涤纶丝;高模低收缩型、高强低收缩型涤纶丝的熔融温度没有明显差异;高模低收缩型涤纶的性能兼顾了高强和高强低收缩丝的优点。     

熔体直纺多孔超细旦涤纶POY丝结构与性能研究

研究了熔体直纺多孔超细旦涤纶预取向丝的取向态结构、条干不匀率、沸水收缩率以及力学性能,研究表明,多孔超细旦涤纶POY丝声模量、取向因子、条干不匀率、断裂强度随单丝纤度的变细而增大,而沸水收缩率、断裂伸长率以及强伸度不匀率却随之下降。     

高收缩涤纶

所谓高收缩涤纶,一般是指收缩率在20～30％左右的纤维,其收缩率大小可根据用途而定,最大的可以达到50％。但高收缩纤维必须在具有较大收缩率的同时,具有较好的强力,并且断裂伸长不宜过大。纤维的收缩与取向无定型相有关,同时与纤维的结晶度有着精确的比例关系(即高取向度,低结晶度的纤维具有较大的收缩     

徐冷温度对聚苯硫醚纤维结构与性能的影响

聚苯硫醚(PPS)脆性较强影响纤维的可纺性,通过在纺丝设备上增设徐冷装置拟旨改变聚集态结构以提高PPS纤维的韧性,研究了徐冷温度对纤维结构与性能的影响.结果表明:徐冷温度对PPS纤维的结晶度有较大影响,其中,随着徐冷温度的升高,PPS初生纤维(UDY)结晶度减小,减小幅度为29.8％,而PPS牵伸丝(DT)结晶度随之增加,增幅为12.0％;UDY取向度随着徐冷温度的升高逐渐减小,降幅为7.8％,DT丝的取向度随着徐冷温度的升高而增加,最大增幅达15.3％,达到175℃时,又呈下降的趋势;随着徐冷温度的升高,PPS DT丝的断裂强度逐渐增大,最大增幅达到9.9％,达到175 ℃后开始降低,断裂伸长率变化趋势与断裂强度相反,最大降幅达到31.2％;随着徐冷温度的升高,PPS纤维的干热收缩率逐渐降低,最大降幅达46.6％,在温度超过175℃时,呈上升趋势,初始模量随着徐冷温度的逐渐增大,最大增幅为12.7％.     

超临界二氧化碳对涤纶纤维结构和性能的影响

分析了超临界CO2染色对涤纶纤维结构和性能的影响。超临界CO2对涤纶纤维有增塑和溶胀作用，纤维的玻璃化转变温度降低。染色后纤维的结晶度增大，结晶尺寸减小，纤维取向度增大。涤纶纤维在超临界CO2中发生热收缩，表面低聚物增多。超临界处理对涤纶纤维的断裂强力没有影响，断裂伸长率增大。     

纺丝条件对基于Lyocell工艺加工的竹浆纤维结构与性能的影响

以竹浆粕为原料,在不同的纺丝条件下采用Lyocell工艺制备了竹浆纤维。采用X射线衍射法、偏光显微镜以及强伸仪对不同纺丝条件下制得的纤维超分子结构以及力学性能进行测定。结果表明：纺丝条件是影响Lyocell工艺竹浆纤维结构与性能的重要因素。随着喷丝头拉伸比的提高,Lyocell工艺竹浆纤维的结晶度及取向增加,从而导致其初始模量和断裂强度相应增大,而线密度和断裂伸长率则相应下降。当喷丝头拉伸比固定不变时,随着纺丝速度的升高,Lyocell工艺竹浆纤维的晶区取向基本不变,非晶区取向及结晶度增加,断裂强度和初始模量增大,断裂伸长率减小。     

Structure–property relationship of different types of polyester industrial yarns

Four major types of polyester industrial yarns (1000 Denier) which are used commercially were studied for their key structural parameters. An attempt has been made to establish a relationship between morphology and properties of these yarns. High tenacity (HT) polyester yarn has the highest birefringence, amorphous orientation, and long period but is relatively less crystalline. High shrinkage characteristic of HT polyester yarn can be accounted for its higher amorphous orientation. High modulus low shrinkage (HMLS) polyester yarn has higher crystallinity and crystal size compared to HT yarn. Fraction of tie molecules of these yarns has been calculated and found that low shrinkage (LS) and super low shrinkage (SLS) yarns have lesser tie molecules. These LS and SLS yarns are tailor-made to achieve lower shrinkage and at the same time maintaining a good level of tenacity. This is achieved with lower amorphous orientation in the final drawn yarn structure. Amorphous orientation was found to have stronger influence than any other structural parameter on the key yarn properties like modulus, tenacity, elongation, and shrinkage.     

Studies on the static and dynamic properties of different types of polyester industrial yarns

Four major types of polyester industrial yarns, viz. high tenacity (HT), high modulus low shrinkage (HMLS), low shrinkage (LS) and super low shrinkage (SLS) polyester yarns, were studied for their static and dynamic properties. An attempt has been made to establish a linkage between static and dynamic properties of these yarns with its structure and with its end applications. HMLS and HT polyester yarns have lower tan δ and work loss, which are the desired characteristics required for its end applications which include tire and conveyer belt. Higher overall orientation and higher fraction of tie molecules helped to achieve these properties in HT and HMLS polyester yarns. LS and SLS polyester yarns are mostly used for static applications. Low thermal shrinkage is the key requirement for the downstream processes of these yarns. Lower amorphous orientation in these two yarns is primarily responsible for achieving very low thermal shrinkage. A good co-relation has been established between the peak temperature of work loss (in slow speed hysteresis test) and the peak temperature of tan δ (in high-speed dynamic test).     

热处理对摩擦纺包芯纱性能的影响

主要讨论了Dref-3型摩擦纺包芯纱包覆层组分的比例（包覆率）以及在干、湿自然状态下热处理对纱线热收缩性、包覆层抗滑脱性及拉伸性能的影响。芯纱采用聚酯长丝,包覆层为棉纤维。实验表明热处理能够明显提高纱线的热收缩性与包覆层抗滑脱性能,而且在湿状态下包芯纱的抗滑脱性能较干状态更好。纱线断裂伸长随着处理温度的增加而增加。包覆率提高,纱线热收缩性降低,抗滑脱性提高,断裂强力增加。     

HMLS高黏合轮胎增强骨架材料生产工艺的优化

以具有高模量、高取向度、高温下尺寸稳定、抗冲击好的HMIS涤纶丝为原料,对其采用直捻法加捻喷气织机织造,并选用环保的嵌段异氰酸酯配制浸胶液浸胶,优化浸胶工艺参数,生产出的高黏合轮胎增强骨架材料的断裂强力为214.8 N,定负荷伸长率4.7%,干热收缩率1.1%,附胶量3.2%,各项指标均优于老工艺,满足了汽车子午线轮胎...     

自卷曲复合长丝PET/PTT纺丝工艺及性能

根据PET、PTT聚合物的特点,介绍了PET/PTT复合长丝的纺丝成形工艺,测试分析了PET/PTT长丝的截面与纵向形态、卷曲形态、热收缩率及其拉伸力学性能。实验结果表明：制得的PET/PTT长丝是以PET和PTT平行并列的双侧结构构成的复合长丝;该长丝经热处理后形成了永久性三维卷曲形态及结构;沸水处理后PET/PTT复合长丝的初始模量、断裂强度有所降低,断裂伸长增大;该复合长丝中PET与PTT的比例对其卷曲性能、弹性回复率、拉伸力学性能、沸水收缩率等都有较大的影响。     

Investigation of Relationship Between Blend Ratio and Yarn Twist on Yarn Properties of Bamboo,Cotton, Polyester,and its Blends

In this study, a series of blended yarns consisting of 80:20 bamboo/cotton, 67:33 bamboo/cotton, 50:50 bamboo/cotton, 33:67 bamboo/cotton, 20:80 bamboo/cotton, 80:20 bamboo/polyester, 67:33 bamboo/polyester, 50:50 bamboo/polyester, 33:67 bamboo/polyester, and 20:80 bamboo/polyester were produced from blends consisting of bamboo/cotton and bamboo/polyester. Besides these, 100% bamboo, 100% cotton, and 100% polyester were also produced. All the yarns were produced with two levels of twist per meter (TPM) 76 and 90. It can be found that the yarn unevenness characteristic was affected by the blended ratio of cotton, polyester, and regenerated bamboo fiber. The drop in tenacity of blended yarns in comparison to the constituents is generally lower which is attributed to the elongation at break of the yarns. The variability in tenacity in respect of 100% polyester yarn is quite high in comparison with other yarns. The yarn elongation at break of bamboo/cotton-blended yarns is found to be lower than those of bamboo/polyester-blended yarns. The variability in the work of rupture is found to be lower for bamboo/cotton-blended yarns. Yarn friction values of the yarns noticed that polyester exhibits the highest value at the TPM of 76. The yarn torque values from which it is noticed that 100% polyester yarns spun with the TPM of 76 have a higher torque in both the wet and dry states. The quality characters of yarn depend upon the ratio of bamboo, cotton, and polyester in the blend ratio.     

PET／PA混纺喷气变形纱的物理性能

为了研究不同混纺比对纱线物理性能的影响,用聚酯（PET）和聚酰胺（PA）复丝制成了混纺喷气变形纱,并测定纱线的性能,如丝圈频率、不稳定性、外形膨松度、沸水收缩率、抗张强度及断裂伸长率。结果发现,与PET含量较高的混纺纱相比,PA含量较高的混纺纱其丝圈不稳定性较低,外形膨松度较小,但伸长率和绞纱收缩率较大。     

喷气涡流纺纱线热黏合增强工艺优化与机制

为探究喷气涡流纺纱线强伸性能提高的有效途径,基于Box-Behnken Design响应面设计方法,研究热处理温度、热处理速度和牵伸倍数对粘胶/低熔点涤纶喷气涡流纱断裂强力及断裂伸长率的影响规律,确定最佳热处理工艺,分析热黏合增强喷气涡流纱的机制。结果表明:喷气涡流纱断裂强力受热处理温度、热处理速度、牵伸倍数、热处理速度二次项、热处理速度和牵伸倍数交互项显著影响;断裂伸长率受热处理温度、热处理速度和二者的交互项显著影响,牵伸倍数影响不显著;响应面优化获得的最佳热处理工艺为热处理温度193 ℃,热处理速度90 m/min,牵伸倍数1.00。优化后纱线断裂强力较原纱提高10.7%,断裂伸长率提高2.8%;低熔点涤纶纤维受热产生挤压变形、点状和团块状热黏合是实现喷气涡流纱热黏合增强的关键。     

竹炭改性涤纶纤维／棉混纺纱线力学性能研究

为了研究竹炭改性涤纶纤维／棉混纺纱中竹炭纤维含量与混纺纱力学性能的变化关系,对不同混纺比混纺纱线在YG061电子单纱强力仪上进行拉伸性能、应力松弛性能测试,并对测试结果进行了分析和比较。结果表明：竹炭改性涤纶纤维／棉混纺纱的断裂强力随着竹炭改性涤纶纤维含量的增加先有逐渐减小的趋势,然后增大。竹炭改性涤纶纤维／棉的混纺比小于临界混纺比时,混纺纱的断裂伸长率变化趋于平直;一旦超过临界混纺比,随着竹炭改性涤纶纤维含量的增加,断裂伸长率迅速增大。在实际应用中,混纺纱最低断裂强度对应的临界混纺比在设计中应尽量避免选用。随着竹炭改性涤纶纤维含量的增加,混纺纱的弹性越来越好。