高压上浆过程中浆液的流变特性

为探讨高压上浆对浆液流变性能的影响,通过实验测量玉米、马铃薯、PVA等浆液在不同质量分数、剪切速率及剪切应力下黏度的变化情况,并分析其流变特性.实验结果表明,在高压上浆过程中,浆纱的速度大幅提高,其剪切速率随之亦显著提高,而浆液黏度则大幅降低.压浆力的提高使得浆液的剪切应力相应增加,而随着剪切应力的增加,浆液的黏度亦随之下降,从而体现出高浓、高压、低黏的高压上浆特点.根据不同浆液的流变性能特点,分析比较马铃薯和玉米淀粉的浆液,认为马铃薯淀粉更适合高压上浆,且马铃薯/PVA混合浆较玉米/PVA混合浆更加适合于高压上浆.

Study on the Rheological Properties of Sizing Agent in High-Pressure Sizing

In order to know the influence of high-pressure sizing on rheological properties of sizing agent,the paper tests the viscosity of maize starch,potato starch and PVA under different conditions.By the rheological properties analysis of these sizing agents,the results show that during high-pressure sizing process,with the increase of sizing speed,the shear rate increases.However,the sizing viscosity decreases.When the sizing stress increases,the shear stress increases.However,the sizing viscosity decreases.That is why the high-concentration size,high sizing stress and low size viscosity could exist together in high-pressure sizing process.It was also found that the better sizing agent for high-pressure sizing is potato starch,and the potato/PVA size is more suitable for high-pressure sizing than maize /PVA size.