苎麻单纤维断裂强力的异常值剔除与不确定度评估

运用夏皮罗-威尔克（Shapiro-Wilk）法对电子强力仪测定的苎麻单纤维断裂强力检测数据的分布特征进行了分析,结果表明其分布近似正态分布。检测数据可按狄克逊（Dixon）法进行检验,剔除异常值。分析了测定强力时产生的不确定度因素,并对其进行了评估,找出了影响测定结果准确度的主要原因。     

苎麻单纤维断裂强力等速伸长测定法研究

阐述了等速伸长法测定纤维断裂强力的先进性,同时系统研究了测定根数、拉伸隔距、拉伸速率等因素对苎麻单纤维断裂强力试验结果的影响。其结果为采用等速伸长法准确测定苎麻单纤维断裂强力奠定了基础。     

苎麻主要品质性状相互关系的研究

苎麻纤维细度、细度均匀度、断裂强力、强度、伸长率及结晶度等品质性状是影响苎麻品质及其可纺性的几项主要因素.本文对30个苎麻品种的主要品质性状进行了研究,并利用断裂强力与纤维直径之间的极显著相关性,建立断裂强力依直径的回归方程y=-1.887+1.756x.     

苎麻主要品质性状相互关系的研究

苎麻纤维细度、细度均匀度、断裂强力、强度、伸长率及结晶度等品质性状是影响苎麻品质及其可纺性的几项主要因素。本文对30个苎麻品种的主要品质性状进行了研究,并利用断裂强力与纤维直径之间的极显著相关性,建立断裂强力依直径的回归方程：y=-1．887＋1．756x。     

不同苎麻品种纤维物理性能的差异及相关性的初步研究

比较研究107个不同苎麻品种纤维物理性能,结果表明单株原麻干重、有效株、断裂功、纤维支数、断裂强力(强度)变异系数较大;单株原麻干重与纤维支数极显著负相关,与断裂强力(强度)显著正相关,与株高极显著正相关;纤维支数与断裂强力(强度)极显著负相关,与断裂伸长(伸长率)极显著负相关;纤维断裂强度(强度)与断裂伸长(伸长率)呈极显著正相关,与断裂功极显著正相关.     

钙氮配施对湘苎三号纤维产量和品质的影响

以湘苎三号为材料,采用田间微区试验研究钙氮配施对苎麻纤维产量和品质的影响.结果表明施尿素150～450kg/hm2时,同一供N水平下,苎麻纤维支数、单纤维断裂强力、含胶率和残胶率与施Ca量显著相关,纤维产量与施Ca量相关不显著；适量尿素和Ca(OH)2配施对苎麻纤维增产效果最显著.本试验条件下,适宜的钙氮配施方案为施尿素300kg、Ca(OH)2 375kg/hm2.合理的钙氮配施对指导苎麻钙氮肥施用,丰富苎麻营养理论,进一步提高苎麻纤维的品质具有十分重要的理论与实践意义.     

不同苎麻品种纤维物理性能的差异及相关性的初步研究

比较研究107个不同苎麻品种纤维物理性能，结果表明：单株原麻干重、有效株、断裂功、纤维支数、断裂强力(强度)变异系数较大；单株原麻干重与纤维支数极显著负相关，与断裂强力(强度)显著正相关，与株高极显著正相关；纤维支数与断裂强力(强度)极显著负相关，与断裂伸长(伸长率)极显著负相关；纤维断裂强度(强度)与断裂伸长(伸长率)呈极显著正相关，与断裂功极显著正相关。     

优质高产多抗苎麻新品种“川苎10号”选育报告

川苎10号(原代号川9505)是以地方品种为基础材料,与多个推广优良品种杂交,采用轮回选择而成的优质高产多抗新品种,在四川省苎麻区域试验中平均原麻产量2283.75kg/hm 2,较对照川苎4号增产23.68%,平均单纤维细度2015.67m/g。品比试验中平均原麻产量2505.0kg/hm 2,较对照川苎4号增产31.02%,平均单纤维细度2038m/g。生产试验中平均原麻产量2583.0kg/hm 2,较对照川苎4号增产22.06%。经农业部麻类产品质量监督检验测试中心检测平均纤维细度2056m/g,纤维强力45.82cN。该品种为深根散生型中偏晚熟品种,抗风力强,雌花极少,高抗苎麻花叶病和苎麻炭疽病。     

苎麻品种纤维形态结构与产量、品质相关性的研究

我们结合苎麻育种实践，在苎麻品种资源圃中选择部分品种，于纤维成熟期取样，用万能固定液固定，甘油一酒精法软化．进行徒手切片观察；并将各品种原麻经化学脱皎后，测定单纤维支数和强力，研究了不同苎麻品种的纤维形态结构与产量，品质的相关性。     

苎麻牵切原理及牵切区断裂点分布的研究

本文主要分析了苎麻单纤维在牵切区内运动及断裂的过程,通过试验考查了断裂点的分布情况.     

Study on the effects of single fiber tensile properties on bundle tensile properties through estimation of HVI bundle modulus and toughness

The HVI properties and Mantis® single fiber tensile properties were analyzed to evaluate the relationship between fiber and bundle tensile properties. For this study, a new method has been developed for estimating the modulus and toughness of cotton fiber bundles directly from the HVI tenacity-elongation curves. The single fiber tensile properties were shown to be translated well into the bundle tensile properties. The single fiber breaking elongation was found to be the most significant contributing factor to bundle tensile properties. The bundle breaking elongation and toughness were shown to increase as the single fiber breaking elongation increased. The bundle modulus increased as the single fiber breaking elongation and/or standard deviation of single fiber breaking elongation decreased.     

工业用大麻纤维的热学性能研究

大麻纤维受热过程中内部结构和物理性能的变化规律是大麻纺织、染整和大麻纤维增强复合材料加工工艺的理论依据,本论文通过对工业用大麻精干麻、原麻纤维的热学性能测试和受热后其束纤维相对断裂强度变化的测试实验,分析了工业用大麻纤维的分解温度、分解阶段和相对断裂强度的变化规律.     

苎麻牵切原理及牵切区断裂点分布的研究

本文主要分析了苎麻单纤维在牵切区内运动及断裂的过程，通过试验考查了断裂点的分布情况。     

Influence of the draw ratio on the mechanical properties and electrical conductivity of nanofilled thermoplastic polyurethane fibers

Electrically conducting textile fibers were produced by wet-spinning under various volume fractions using thermoplastic polyurethane (TPU) as a polymer and carbon black (CB), Ag-powder, multi-walled carbon nanotubes (MWCNTs), which are widely used as electrically conducting nanofillers. After applying the fiber to the heat drawing process at different draw ratios, the filler volume fraction, linear density, breaking to strength, and electrical conductivity according to each draw ratio and volume fraction. In addition, scanning electron microscopy (SEM) images were taken. The breaking to strength of the TPU fiber containing the nanofillers increased with increasing draw ratio. At a draw ratio of 2.5, the breaking to strength of the TPU fiber increased by 105 % for neat-TPU, 88 % for CB, 86 % for Ag-powder, and 127 % for MWCNT compared to the undrawn fiber. The breaking to strength of the TPU fiber containing CB decreased gradually with increasing volume fraction, and in case of Ag-powder, it decreased sharply owing to its specific gravity. The electrical conductivity of the TPU fiber containing CB and Ag-powder decreased with increasing draw ratio, but the electrical conductivity of the TPU fiber containing MWCNT increased rapidly after the addition of 1.34 vol. % or over. The moment when the aggregation of MWCNT occurred and its breaking to strength started to decrease was determined to be the percolation threshold of the electrical conductivity. The heat drawing process of the fiber-form material containing the anisotropic electrical conductivity nanofillers make the percolation threshold of the electrical conductivity and the maximum breaking to strength appear at a lower volume fraction. This is effective in the development of a breaking to strength and electrical conductivity.     

Study on characteristics of compact yarns under dynamic state

The dynamic testing conditions simulate actual manufacturing conditions more closely than static testing. In most cases, as results from dynamic tests differ significantly from static tests, dynamic tests are more relevant from the point of view of processing of yarn. The yarns are in motion when they are running on different machines during the production process viz. weaving; knitting etc. Compact ring spun yarns have created a fundamental change how the industry views the ring spinning. The new technology compact yarns such as EliTe® yarns need to be compared with the normal doubled yarns in a dynamic way. This study involves dynamic testing of the EliTe® compact yarns and normal ring spun doubled yarns using CTT (Constant Tension Transport) machine, a versatile test instrument to measure the yarn properties such as dynamic breaking strength, elongation, abrasion, lint, yarn faults (thick, thin places, neps), hairiness etc. EliTe® compact yarns showed higher breaking strength, more elongation, with lesser yarn faults and hairiness, less abrasiveness and less lint generating tendencies during the dynamic testing as compared to the normal ring spun doubled yarns.     

Mechanical properties of wool fiber in the stretch breaking process

Short wool fibers obtained by the stretch breaking process can be blended with cotton fibers and processed in a cotton spinning system, which has a high production rate. For the structural property of the wool fiber after stretch breaking, the diameter and length of the wool fiber were measured as a function of time. The diameter of the broken fibers was finer than the diameter of untreated fibers. The fiber diameter at the break point was the finest and was more irregular than the original fiber. The broken fiber showed mechanical properties of increased modulus, decreased breaking strain, and increased breaking strength.     

Effect of surface treatment on the structure and properties of para-aramid fibers by phosphoric acid

The surface of para-aramid fiber was modified by phosphoric acid solutions (H3PO4) based on an orthogonal experimental design and analysis method. Statistical results indicate that treatment temperature is the most significant variable in the modification processing, while treatment time was the least important factor. The structure and morphology of the modified fiber were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction instrument (XRD), and scanning electron microscope (SEM). The results showed that some polar groups were introduced into the molecular structure of aramid fibers and the physical structure of the treated fibers was not etched obviously. The interfacial properties of aramid fiber/epoxy composites were investigated by the single fiber pull-out test (SFP), and the mechanical properties of aramid fibers were investigated by the tensile strength test. The results showed that the interfacial shear strength (IFSS) of aramid/epoxy composites was remarkably improved and the breaking strength of aramid fibers was not affected appreciably after surface modification.     

Modeling the tensile strains of non-uniform fibers

The maximum strain experienced by the thinnest segment of a non-uniform fiber governs fiber breakage, yet this maximum strain can not be obtained from a normal single fiber test. Only the average strain of the whole fiber specimen can be obtained from a normal single fiber tensile test. This study has examined the relationship between the average strain, the maximum strain and the degree of fiber non-uniformity, expressed in coefficient of variation (CV) of fiber diameters along fiber length. The tensile strain of irregular fibers has been simulated using the finite element method (FEM). Using this method, average and maximum tensile strains of non-uniform fibers were calculated. The results indicate that for irregular fibers such as wool, there is an exponential relationship (i.e.ɛ _ave ɛ _max=ae ^{−b CV} ) between the ratio of average breaking strain and maximum breaking strain (ɛ _ave ɛ _max) and the along-fiber diameter variation (CV). The strain ratio decreases with the increase of the along-fiber diameter variation.