衣架型模头中熔融聚合物流动的三维有限元分析

研究了聚合物熔体在衣架型模头中的等温流动。采用幂律模型描述该熔体的流变行为,通过三维有限元方法对此流动进行模拟,从而得到其速度场的分布情况,并且着重讨论了衣架型模头的几何形状对速度场分布的影响,特别是对出口宽度方向速度均匀性的影响。     

转杯纺自由纱段形态对其捻度分布的影响

通过对自由纱段的运动及受力分析，对自由纱段形态以及纺纱工艺参数对自由纱段捻度分布的影响进行了研究。研究表明：因自由纱段在杯内成弯曲形状，从而使得自由纱段捻度自假捻盘入口处向剥离点处不断减少，真至剥离点处纱条捻度甚至降到只有设计捻度的40%-80%。为了保证凝聚槽内一定的捻度传递长度，则须适当提高设计捻度，这就揭示了转杯纱设计捻度高于环锭纱的一个主要原因。高速细支时的剥离点纱条捻度相对于低速粗支而言要高，说明只要一些纺纱工艺参数如转杯直径、转杯速度、假捻盘规格等配合得当，转杯纺也可高速稳定地纺制细支纱。     

Realization of Orthogonal Wavelets Adapted to Fabric Texture for Defect Detection

The wavelet adapted to the fabric texture can be developed from the orthogonal and normal series which are selected randomly by means of Monte Carlo method and optimized by adding certain constraint conditions. Then the fabric image can be decomposed into the subimages by the adaptive wavelet transform and the horizontal and vertical texture information will be perfectly contained in the subimages. Therefore this method can be effectively used for the automatic inspection of the fabric defects.     

气流纱的拉伸特性研究

本文讨论气流纱的拉伸特性。Hearle曾对具有理想结构纱线的拉伸特性进行过比较完整的研究工作。本文则根据气流纱独特的成纱结构,对Hearle理论在气流纱中的应用作了一定的修正,并在此基础上对气流纱的拉伸特性作了分析计算。计算结果与实测结果基本相符。最后还从气流纱的应力-应变关系式中,就影响气流纱强力、初始模量以及断裂功等等力学特性的一些主要工艺参数进行了分析讨论。得出合理选用阻捻盘、很好控制捻度传递长度;合理设计与选用分梳及输棉机构,在不断改善单纤维供应的同时,尽量减少纤维损伤,提高纤维有效长度;适当提高纺纱张力,增加纤维转移等等都是改善气流纱强力等力学特性、提高成纱质量的有效途径。对工业用气流纱,还可通过合理设计凝棉槽,以提高气流纱紧密度的途径来提高气流纱强力。     

液固相组合过滤材料研究

通过对活性炭、非织造布和微孔滤膜过滤特性的研究,根据过滤机理,利用虚拟变量法优选并制备了由该三种材料组成的组合过滤材料。结果表明,使用这种过滤材料较单一成分过滤材料具有较好的过滤特性。     

转杯纺杯内纱段捻度分布研究

通过对纱条在假捻盘上的运动和受力分析,对转杯纺杯内的捻度分布进行研究,并得到了杯内捻度分布的一般规律.     

Mechanism of Kenaf Retting Using Aerobes

The experimental results showed that the duration of microbial retting processing of kenaf fibers by using aerobic microbe was four times shorter than that by using anaerobic microbe. The residual gum percentage, breaking strength, breaking elongation and linear density of aerobic retted kenaf bundle fibers did not show significantly difference with that of anaerobic retted kenaf bundle fibers by ANOVA-Tukey's studentized test at a = 5% except for the softness. The bioenergetic principle and the calculation of the amount of ATP produced during the decomposition processing of kenaf gums were used to explain why the retting duration in the case of using aerobic microbes was much shorter than that of using anaerobic microbes.     

The State of the Kenyan Cotton Growing Industry

From the early 1960s to late 1980s, the Kenyan cotton growing industry played a vital role in the Kenyan economy in terms of provision of employment and creation of wealth in the rural areas. It also played a central role in the textile industry which was thriving during the above mentioned period. Over the years, cotton production in Kenya has fallen steadily, such that by the year 2000, the country experienced a severe cotton fiber deficit. This study was undertaken to investigate the trend of the cotton growing industry in Kenya. Selected aspects of the industry like cost of production, cotton seed distribution, the operation of cotton gins and the quality of cotton lint were considered. Kohonen Self Organizing Maps （SOM） and K-means clustering techniques were used in data analysis. The results of this study show that Kenyan cotton farmers produced seed cotton at a break-even price of US $ 0.31 per kilogram, while the price offered was US $ 0.29 per kilogram.     

苎麻纯落麻转杯纺假捻盘磨损研究

本文通过转杯纺在运转条件下加工苎麻纯精梳落麻的磨损试验方法,对表面镀铬及渗硼假捻盘进行了磨损试验。通过观测各假捻盘磨损前后的体积变化以及表面形貌扫描电镜照片,分析了各假捻盘的磨损机理,得出渗硼假捻盘耐磨性优于镀硬铬假捻盘的结论,建议在生产实践过程中对渗硼假捻盘进一步考察应用。     

超声波对羊毛纤维表面形态与内部结晶的影响

羊毛表面的鳞片层由于疏水性强,是羊毛上染的初始壁障,羊毛内部皮质层的规整堆砌结构也影响染料在羊毛内部的渗透与扩散.采用扫描电镜和X-射线衍射技术分别观察和测试了超声波作用下羊毛表面形态以及内部结晶度的变化.结果发现,经超声波处理后,羊毛表面鳞片被刻蚀,边缘破损；羊毛表面有无定形物碎片沉积以及波纹状条痕；鳞片倾角增大,鳞片交叠处有无定形物析出；此外,羊毛结晶度有一定程度下降,可以推测,这些现象和结果有利于初始上染壁障的削弱以及纤维内部透染的改善,从而提高羊毛的染色性能.