【作者】 刘玉敏；

【导师】 钱坤；

【作者基本信息】 江南大学 ， 纺织工程， 2008， 硕士

【摘要】 纺织上浆用的浆液是一种非牛顿流体,其粘度在浆纱的上浆过程中并非固定不变,而是随着浆液剪切速率的变化而变化,由此影响着浆纱的上浆性能。尤其对于高压上浆来说,浆纱的速度有了显著的提高,浆液的剪切速率较之普通(常压)上浆有了显著的提高。剪切速率的变化对上浆速度、上浆率具有较大的影响,研究高压上浆过程中浆液剪切速率的变化对于全面理解高压上浆,进一步控制与提高高压上浆的质量具有重要的意义。本课题在研究不同浆料的流变性能的基础上,研究高压上浆过程中浆液的流变性能,主要研究速度的变化对浆液流变性能的影响,并进一步研究浆液流变性能的变化与上浆率、浆纱速度、压浆力的关系,以找到它们相互间的科学规律,从而合理地制定高压上浆工艺,确保高压上浆的质量。主要研究内容包括:1、研究剪切速率对浆液流变性能的影响。2、研究高压上浆过程中浆纱速度的提高对浆液流变性能的影响。3、研究几种不同浆液的流变性能,并进行相互的比较。并通过比较与分析研究,选择最优的适合高压上浆的浆液品种。4、研究高压上浆过程中浆液浓度对其流变性能的影响。5、研究压力的提高(主要是压浆力的提高)对浆液流变性能的影响。通过分析和研究,得出结论:1、随着剪切速率的增大,浆液的粘度会逐渐变小。当剪切速率较低时,粘度的变化比较明显,粘度由高到低的下降速度很快,后来随着剪切速率的不断增大,当剪切速率达到一定的范围时,浆液粘度的变化较小,逐渐趋于缓和。且浆液浓度越大,由剪切速率引起的粘度变化幅度越大,变化趋势越明显。结合同心圆筒旋转粘度计测量原理,得出高压上浆过程中浆液的剪切速率变化范围一般为12～40 l/s。2、在浓度相同,剪切速率差别很小时,马铃薯原淀粉浆液的粘度较玉米原淀粉浆液的粘度低,而在高压上浆中,浆料的配方应在含固率不变的前提下,适当降低粘度,且比较相同剪切速率下不同浓度淀粉浆液的粘度,发现马铃薯原淀粉的粘度值变化幅度较小,表现更为稳定,所以推断马铃薯原淀粉更符合高压上浆的要求。3、由实验可以得出,随着混合浆液中PVA含量的不断提高,浆液的起始粘度随之降低。且相同条件下,马铃薯/PVA混合浆的粘度明显低于玉米/PVA混合浆的粘度,由此我们可以得出,前者更适合于高压上浆。4、高压上浆过程中,浆纱速度大幅提高,浆液的剪切速率随之显著提高,从而使得浆液粘度大幅降低,且浆纱速度所引起的剪切速率(12～40 l/s)处于浆液粘度随剪切速率的增大而下降较明显的那一段,当剪切速率达到一定数值时(50 l/s左右),浆液的粘度逐步趋于稳定,实现高浓、低粘的上浆特点,这是高压上浆和常压上浆之间的本质区别。5、高压上浆过程中,浆纱速度增大的同时,压浆力也相应地增加,而压浆力的提高也使得浆液的剪切压力相应增加,且随着剪切压力的增加,浆液的粘度随之下降,当剪切压力达到一定数值时,浆液的粘度逐步趋于平稳。这与剪切速率对浆液流变性能的影响基本相同。论文最后对课题今后的发展方向进行了展望。更多还原

【Abstract】 As a kind of non-newton fluid,the sizing agent has a variable viscosity during the sizing process of textile yarns.It’s viscosity changes along with the changing of shear rate of the sizing agent.And it brings the effect to sizing performance of the sizing textile yarns.The shear rate of sizing agent improves greatly after the significant improvement of the sizing speed in high-pressure sizing process.It has much influence on the sizing speed and sizing ratio of the textile yarns.The study on the variadness of the sizing agent shear rate in high-pressure sizing will have a terrible concernful meaning to the deeply understanding and better cotrolling of high-pressure sizing.Based on the research of theological performance of several kinds of sizing agent,the paper studies the rheological properties of the textile size in high-pressure sizing process.It focus on the study of effect to the rheological performance of size caused by the improvement of sizing speed.It also studies the relationship between rheological performance and sizing ratio,sizing speed,sizing pressure.Thus to find the regularity among them and it will be beneficial to optimize the sizing process and improve the sizing quality subsequently.The paper includes several aspects as below:1.The impact of shear rate to theological performance of size was studied.2.In order to find the impact of sizing speed to size’s theological performance,the theological performance of several kinds of sizing agent were studied in high-pressure and normal-pressure sizing respectively.3.The rheological performance of several kinds of sizing agent were studied and compared to find the best suitable sizing agent for high-pressure sizing.4.The impact of concentration to theological performance of size in high-pressure sizing was studied.5.The influence of sizing pressure to size’s theological performance was alse studied in this paper.After analying,some deductions were attained.It follows as below:1.The viscosity of size decreases as the shear rate increases gradually.The viscosity drops quickly when the shear rate is at a low level.With the increase of shear rate,the viscosity changes slightly when the shear rate reaches certain area.And with the increase of the size concentration,the viscosity’s rangeability increasees too.According to the concentric cylinder rotation viscometry,we find that the shear ratio comes within 12～40 1/s in hige-pressure sizing.2.The viscosity of potato starch is more lower and steady than corn starch at the same concentration and shear rate.So the patato starch is much better than corn starch in high-pressure sizing,for the lower viscosity of size is more suitable for high-pressure sizing when their concentration is all the same.3.With the increase of PVA in the mixed size,the initial viscosity of the size drops consequently.And at the same conditions,the viscosity of the size of mixed patato and PVA is much lower than mixed corn and PVA.Thus the former is more suitable for high-pressure sizing.4.in the process of high-pressure sizing,with the increase of sizing speed and shear rate,size viscosity decreases sharply.When the shear ratio reaches a certain point,the size viscosity will be steady,It meets the need of high-pressure sizing for the high-concentration and low-viscosity size.It’s the key difference between high-pressure sizing and nomal-pressure sizing.5.During the high-pressure sizing process,sizing pressure and the shear pressure increases together at the same time of the increase of sizing speed.It result eventually in the decrease of size viscosity.And the size viscosity decreases sharply in the shear ratio of 12～40 1/s.When the shear pressure reaches a certain point,the size viscosity will be steady,The regularity is the same as shear ratio to size viscosity.Finally,this discourse illustrates the prospects of the developing direction of this topic.更多还原