Properties of recycled poly (ethylene terephthalate) (PET)/hyperbranched polyester (HBPET) composite fibers

Hyperbranched polyester (HBPET) with aliphatic–aromatic structure was synthesized and extruded with recycled poly (ethylene terephthalate) (RPET) chips obtained from used water bottles, with ratio of 0.5% and 1?wt% of HBPET. Filament fibers from pure recycled PET (RPET-0) and (RPET-0.5 and RPET-1) composite were spun using a melt spinning process and drawn by a thermal drawing process to improve their mechanical properties. The effects of addition of HBPET on the properties of produced fibers as well as draw ratio are investigated by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (XRD), universal tensile analysis, and sonic velocity. It was found that mechanical properties of the (RPET-0.5 and RPET-1) fibers were improved with respect to pure recycled PET (PET-0) fibers. Moreover, the crystallinity of composites fibers was also increased with an increasing of HBPET content. The improvement in mechanical properties may be due to the increase of orientation of fiber molecules along the fiber axis. Moreover, addition of HBPET serves as lubricant within recycled PET matrix which increased its mechanical properties.     

生活用纸浆料纤维分析(Ⅰ)

对以废纸浆和原生浆生产的卫生纸原纸及其浆料进行纤维染色分析,探索这2个系列卫生纸原纸的纤维组成及形态差异.结果表明,废纸浆及其生产的卫生纸原纸中的纤维均可见油墨脏迹,有较高的有效残余油墨含量及荧光白度;与原生浆纤维相比,废纸浆纤维组成较复杂,均含有机械浆纤维甚至未分散开的机械浆纤维束,纤维帚化率较高.     

利用废弃聚酯制品生产纺织纤维

为了深入研究利用废弃聚酯制品制造高质量纺织纤维,从而减少环境污染,促进可持续发展,综述了近年来采用废弃聚酯制品制造纤维的加工技术、国内外研究发展现状,并分析了存在的问题。分析表明,采用化学再生法,可利用废弃聚酯制品制得高质量纺织纤维。并认为今后研究重点应放在聚酯解聚、分离提纯和再聚合纺丝上,以提高再生纤维品质;醇解法和超临界流体法等新型分解提纯方法具有广阔的发展前景。     

Effects of drawing process on crimp formation-ability of side-by-side bicomponent filament yarns produced from recycled,fiber-grade and bottle-grade PET

In this study, side-by-side bicomponent filaments from recycled poly(ethylene) terephthalate (R-PET) from post-consumer bottles, fiber-grade PET (FG-PET) and bottle-grade PET (BG-PET) successfully were extruded. The bicomponent fibers in the forms of FG/R, BG/R and FG/BG were produced in a spinning machine and drawn by a thermal drawing process to improve their mechanical properties using draw ratios between ‘2.5 and 2.8’. The effects of conditions on the fiber structure, physical properties and crimp formation of resultant fibers were evaluated. The birefringence, shrinkage and mechanical properties, such as tensile strength and tensile modulus, increased and elongation at break decreased for the drawn fibers, and this was attributed to the fiber orientation. Distinct crimp formation was observed from drawn bicomponent fibers after thermal treatment. There were significant birefringence and shrinkage difference between two components in drawn bicomponent fibers caused to severe crimp formation.     

生活用纸浆料纤维分析（Ⅱ）

对B、D卫生纸厂原生浆系列及E卫生纸厂废纸浆系列卫生纸原纸生产线上的浆料及卫生纸原纸进行纤维染色分析,对比了用原生浆及废纸浆抄造的卫生纸原纸的纤维形态。结果表明,废纸浆及用其抄造的卫生纸原纸的纤维上均可见油墨脏迹,荧光白度及有效残余油墨含量高;纤维组成较复杂,含有机械浆纤维及未分散开的机械浆纤维束;纤维帚化率较高。     

Structures and flammability properties of polyethylene terephthalate(PET) fibers containing encapsulated carbon materials

In this paper, carbon nanotubes (CNTs) and carbon microspheres (CMSs) have been microencapsulated to obtain microencapsulated carbon nanotubes (MCNTs) and microencapsulated carbon microspheres (MCMSs). Moreover, a series of PET fibers with CNTs/CMSs or MCNTs/MCMSs were prepared by melt spinning. Morphologic structures, mechanical, thermal, and flame retardant properties of MCNTs/MCMSs /PET fibers have been studied by TEM, SEM, electronic tension meter, DSC, TG, limiting oxygen index (LOI), and vertical flammability instruments. The results show that the tensile strength of MCNTs/MCMSs/PET fibers are increased because of better dispersion and compatibility of MCNTs/MCMSs in PET and enhanced orientation degrees of fibers, compared with CNTs/CMSs/PET fibers. Moreover, the highest values of mechanical properties are observed with 0.4 wt% content. Meanwhile, the MCNTs/MCMSs/PET fibers have good thermal stabilities and their fabrics have higher LOI value of 25.3%, reaching B1 class of China standard GB 17591-2006. Overall, this method endowed the MCNTs/MCMSs/PET fibers with the good mechanical and flame-retardant properties.     

Decontamination efficiency of a new post-consumer poly(ethylene terephthalate) (PET) recycling concept

The aim of the study was to investigate and evaluate the cleaning efficiency of a new recycling concept for post-consumer poly(ethylene terephthalate) (PET). The so-called Flake To Resin (FTR®) recycling process produces PET pellets or preforms from conventionally recycled PET flakes for the application in new PET packaging in direct food contact. The investigated process can be considered as 'super-clean' recycling process and was developed to introduce conventional recycled post-consumer (PCR) PET flakes up to an amount of 50% into the pellet and preform production. Within the study the cleaning efficiency of the investigated FTR process was determined by a challenge test. The experimental results obtained from three challenge tests with different input concentrations of the surrogates and different amounts of post-consumer PET flakes show that all applied surrogates are very efficiently removed by the investigated recycling process. The cleaning efficiencies for all surrogates are above 99.9%. In the final product of the process no surrogates could be determined above the detection limits (0.5 mg kg^-1) even if the initial concentrations were in the percentage range. From a migrational point the final product, which are either PET pellets or preforms, was similar to virgin PET. Only the PET typical substances acetaldehyde and ethylene glycol had slightly higher concentrations than found in a conventional PET virgin sample used as reference. The generally accepted migration limit of 10 µg kg^-1 for the surrogates in the final products of the challenge tests is established for all kinds of foodstuffs.     

Decontamination efficiency of a new post-consumer poly(ethylene terephthalate) (PET) recycling concept

The aim of the study was to investigate and evaluate the cleaning efficiency of a new recycling concept for post-consumer poly(ethylene terephthalate) (PET). The so-called Flake To Resin (FTR®) recycling process produces PET pellets or preforms from conventionally recycled PET flakes for the application in new PET packaging in direct food contact. The investigated process can be considered as ‘super-clean’ recycling process and was developed to introduce conventional recycled post-consumer (PCR) PET flakes up to an amount of 50% into the pellet and preform production. Within the study the cleaning efficiency of the investigated FTR process was determined by a challenge test. The experimental results obtained from three challenge tests with different input concentrations of the surrogates and different amounts of post-consumer PET flakes show that all applied surrogates are very efficiently removed by the investigated recycling process. The cleaning efficiencies for all surrogates are above 99.9%. In the final product of the process no surrogates could be determined above the detection limits (0.5?mg kg^?1) even if the initial concentrations were in the percentage range. From a migrational point the final product, which are either PET pellets or preforms, was similar to virgin PET. Only the PET typical substances acetaldehyde and ethylene glycol had slightly higher concentrations than found in a conventional PET virgin sample used as reference. The generally accepted migration limit of 10?µg kg^?1 for the surrogates in the final products of the challenge tests is established for all kinds of foodstuffs.     

High-performance hybrid composites made of recycled Nomex,Kevlar, and polyester selvages: mechanical property evaluations

In modern age, prosperous business, industrial, social, and leisure activities improve and ensure the quality of lives considerably, but are inevitably accompanied with insecurity and dangers that lurk anywhere anytime. People are concerned about safety and have increasing demands on self-protection in terms of working/living environment, accidents, and raising crime rates. The increasing demands of protective textiles cause the mass production of high performance fabrics, leaving considerable amount of high performance selvages. In this study, three kinds of high performance recycled selvages, including Nomex, Kevlar, and PET selvages, are used to make high-performance hybrid composites. The recycled selvages are smashed into staple fibers using a nonwoven manufacturing process. Each recycled staple fibers are individually combined with low-melting-point polyester (LPET) fibers at ratios of 9:1, 7:3, and 5:5, and processed with thermal compression. The LPET fibers contribute to the hybrid composites with thermal bonding points, which decrease the voids between fibers, limit the fiber slide, and enhance the friction force between fibers. The shearing, expelling, and friction functionalities of LPET fibers are expected have a positive influence on the mechanical properties of the high-performance hybrid composites. The morphology of hybrid composites is observed using a scanning electron microscope, and the air permeability, tensile strength, tearing strength, and bursting strength of hybrid composites are evaluated, examining the optimal parameters.     

静电和熔融纺丝法对PET纤维表面结构的影响

采用扫描电子显微镜(SEM)、原子力显微镜(AFM)和差示扫描量热仪(DSC)对溶液和熔融静电纺丝法所制备的PET纤维,以及工业熔融纺PET纤维的表面形貌和热学性能进行分析比较.结果表明,因加工成纤方式不同,熔融静电纺纤维表面光滑匀整,工业熔融纺纤维表面有明显的凹凸波浪纹,而溶液静电纺纤维表面略显蜂窝状结构.由DSC分...     

牵伸速度对PET纺粘纤维凝聚态结构的影响

在纺粘非织造布加工过程中,通过调整牵伸风的速度,制得不同结构的聚对苯二甲酸乙二醇酯(PET)纤维,研究了牵伸风速度对纺粘PET纤维外观形貌、直径、结晶度和取向度的影响。结果表明:牵伸风速度对纤维表观形貌没有影响;随着牵伸风速度的增加,PET纺粘纤维的直径逐渐减小,当牵伸风速度达到一定值后其对纤维直径的影响较小;PET纺粘纤维的结晶度低于15.0%,牵伸风速度对其影响不大;随着牵伸风速度的增加,PET纤维晶区的取向度逐渐增加,当牵伸风速度达到一定值后对其晶区取向度影响较小。     

Insitu Self-Assembly of Bacterial Cellulose on Banana Fibers Extracted from Peels

ABSTRACT

In this research work, in-situ self-assembly approach was used the first time, to cultivate bacterial cellulose on the surface of fibers, extracted from banana peels. The characterization was performed using SEM, FTIR, and single fiber tensile test in order to determine the surface morphology and mechanical properties of modified fibers. As-prepared hybrid fibers exhibited comparatively better mechanical properties, which can be attributed to the self-assembly of bacterial cellulose on banana fibers’ surface. Overall, this research work suggests a novel route for fiber extraction from banana peels and to use them for the preparation of bio nano-composites with improved mechanical properties.     

水刺非织造布专用涤纶短纤维性能的研究

分析了普通棉型涤纶短纤维、水刺专用一般亲水涤纶短纤维、水刺专用高亲水涤纶短纤维的结构和性能,研究表明亲水处理对水刺专用涤纶短纤维的表面形态、摩擦性能、比电阻、吸湿性能等有较大的改善,介绍了3种涤纶短纤维在水刺非织造布产品中的应用特点。     

涤纶增强混凝土的性能研究

采用涤纶工业丝和相应的废弃的涤纶工业丝作混凝土的增强纤维,分别选择纤维的长度为20、30 mm和纤维的掺量为0.5、1.0、1.5 kg/m3,按国标要求制作试样并进行标准养护后,对增强混凝土的抗裂性能、抗压性能、劈裂抗拉性能和弹性模量进行测试和分析,结果表明纤维增强混凝土的上述力学性能均有所改善,试样受力破坏后不碎裂;并且随着纤维长度和掺量的增加,抗压强度和劈裂抗拉强度提高;回收涤纶与新涤纶的情况大体类似,这给废弃涤纶的回收再利用和节约资源、保护环境提供了途径。不论是涤纶还是回收涤纶,长度为30 mm、掺量为1.5 kg/m3的试样表现出最优的力学性能。     

Low-density polyethylene/sugarcane fiber composites from recycled polymer and treated fiber by steam explosion

Low-density polyethylene (LDPE) has caused serious environmental damages, and it has been a challenge for waste management in large cities. The LDPE recycling as composites with natural fibers such as sugarcane fibers (SCF) has been an interesting alternative to conciliate economic aspects with environmental benefits. In this study, SCF has been treated by steam explosion and incorporated to low-density polyethylene waste (LDPEW) to generate LDPEW/SCF composites with higher fiber/polymer interaction and improved mechanical properties. LDPEW/SCF composites with fibers content until 20 wt% showed mechanical properties with performance adequate for nobler applications when compared to the isolated recycled LDPEW.     

聚乳酸和涤纶纤维的鉴别方法

对聚乳酸(PLA)和聚对苯二甲酸乙二酯(PET)纤维的鉴别方法进行了探讨。结果表明,PET纤维具有比PLA纤维更致密的结构,有些PLA纤维横截面上的孔洞或裂缝用生物显微镜就能观察到。PET和PLA纤维的红外吸收光谱有明显的差别,在差热性能上,PET纤维的熔融温度和峰顶温度比PLA纤维的分别高90℃和84℃。碱性条件下(pH值为11.8)对PLA纤维的强度有明显损伤,而对PET纤维的强度损伤并不明显,这种性能也可以用来进行对2种纤维的定性鉴别。     

聚酯短纤维与二元油剂界面的分形研究

将分形理论和方法用于油剂与聚酯短纤维的研究,从微观结构及机制上研究油剂施覆于聚酯短纤维表面后的形貌特征及摩擦性能,通过不同含油纤维分形维数的计算,定量地评价油剂在纤维表面的分布状态,解析油剂乳液粒径形成的复杂非线性过程,判断在不同纺丝阶段施覆于聚酯短纤维表面的A/B二元油剂的形貌特征,从而可优化油剂使用条件,对减少应用实验的风险具有指导作用。     

Paper Properties of Typha Latifolia,Pennisetum Alopecuroides,and Agave Americana Fibers and Their Effect as a Substitute for Kraft Pulp Fibers

In this study, we have extracted and bleached fibers from three plants (Typha latifolia, Agave americana, and Pennisetum alopecuroides). The obtained pulp contains more than 50% of fines and fibers with lengths not exceeding 1 mm. Generally, the amount of fines depends on fiber source, fiber morphology, pulping conditions, and the extent of mechanical treatment. Handsheets were produced with plant fibers alone or mixed (in different percentages: 7.5%, 15%, 22.5%, and 30%) with a commercial kraft pulp. The mechanical and optical properties of the sheets (breaking length, tear index, young modulus, whiteness, and opacity) show that plants could be used as a substitute fiber supply for the paper industry. However, fines were hardly retained in the sheets. A model to explain the removal of fines is proposed.     

共混改性改善高低黏度PET并列复合纤维性能的研究

选取高黏度PET、低黏度PET添加PBT的混合物作为并列纺丝的两种组分进行复合纺丝,并对其可纺性进行研究;采用与不经改性的高低黏度PET并列复合纤维的力学性能对比进行研究。结果表明,高黏度PET/(低黏度PET混合PBT)并列复合纺丝具有良好的可纺性及后加工性能,纺制的复合纤维具有较好的力学性能及自卷曲性能。     

回用纤维表面的物理和化学变化

研究了硫酸盐浆、酸性亚硫酸盐浆、氢氧化钠浆、碱性亚硫酸盐浆1次回用后纤维的形态、纤维表面的物理及化学变化。结果表明,纸张经1次回用后,回用浆中细小纤维的含量明显增加,纤维平均长度变化不大,纤维的柔软性降低,卷曲指数和扭结指数下降;电镜分析显示,回用纤维的表面和原纤维的表面特征相似,密实光滑,但与原纤维表面相比,回用纤维暴露出较多的S2层,即纤维表面部分复合胞间层在回用过程中脱落;实验的4种浆料经回用后,纤维表面的O/C原子比均下降,氢氧化钠浆的O/C原子比下降得最多达22%,而酸性亚硫酸盐浆O/C原子比只下降3.4%。