液体在针织物纵向传导的机理研究

Longitudinal Wicking of Weft Fabrics

Washburn方程被广泛地认为是液体芯吸的动力学描述,但有争议的是其对所有有孔介质的有效性。本研究发现,液体在垂直放置的织物中传导时有饱和区和非饱和区的存在,水平传导时没有发现明显的非饱和区。同时,Washburn方程能较好地描述液体水平传导时传导距离与传导时间的关系,在垂直传导时Washburn方程仅能较好地描述饱和区传导距离与传导时间的关系,而考虑饱和区和非饱和区的传导距离与传导时间的关系时,Washburn方程不能成立。

The Washburn equation is widely regarded in wicking kinetics. However, there exists a controversy over its validity for all kinds of porous media. For assessed knitted fabrics in this study, both a saturated zone and an unsaturated zone in vertical wicking were found though in horizontal wicking the unsaturated zone did not significantly exist in the sample strips. The investigation showed that the value of time exponent in the Washburn equation in horizontal wicking was around 0.5, which was in agreement with the value predicted by the equation. In vertical wicking, the Washburn equation predicted quite well the relationship between the saturated wicking length and wicking time. For the wicking length including both the unsaturated and saturated zones, the value of time exponent was found to be less than 0.5, so the Washburn equation was not well obeyed in vertical wicking if the unsaturated zone and saturated zone were not differentiated from each other.