A Theoretical and Experimental Study of Oil Wicking Mechanism of Kapok Fibrous Powder Assembly

ABSTRACT

Kapok fiber has a large lumen with a natural waxy surface which endows it with distinct hydrophobic-oleophilic properties. Oil-impregnated kapok fibrous powder (KFP) has great potential as a lubricant carrier material. To study the oil wicking mechanism of KFP assemblies with different pore structures (interfibrous pores and the lumens), a dual-scale model was established based on Washburn capillary theory. The theoretical model was verified by capillary rise test of KFP assemblies in various packing densities ranging from 0.08 g/cm³ to 0.14 g/cm³. It was found that the experimental results have good consistency with theoretical values at low packing densities. The deviation between the experimental result and the theoretical value increases with the increase of packing density. This can be largely attributed to compression of the lumens at increased packing density, leading to the reduction of oil sorption capacity within the lumens. The outcomes of this research are believed to provide important references for the usage of fibrous powder materials as lubricant carrier.

摘要

木棉纤维有一个大的管腔和一个天然的蜡状表面，这赋予了它独特的疏水亲油特性. 油浸木棉纤维粉末（KFP）作为润滑剂载体材料具有很大的潜力. 为了研究具有不同孔结构（纤维间孔和管腔）的KFP集合体的吸油机理，基于Washburn毛细管理论建立了双尺度模型. 通过在0.08 g/cm3至0.14 g/cm3的各种填充密度下的KFP集合体的毛细管上升试验验证了理论模型. 结果表明，在低填充密度条件下，实验结果与理论值具有良好的一致性. 实验结果与理论值的偏差随着填料密度的增加而增大. 这在很大程度上可归因于在增加的填充密度下管腔的压缩，导致管腔内的油吸附能力降低. 本研究成果可为纤维粉末材料作为润滑剂载体的应用提供重要参考.

KEYWORDS:

• Kapok fibrous powder
• wicking
• sorption mechanism
• dual-scale

关键词:

• 木棉纤维粉末
• 芯吸
• 吸附机理
• sx双尺度

Highlights

• Oil-impregnated kapok fibrous powder (KFP) as a potential lubricant carrier material was proposed.

• According to the characteristics of KFP assembly, a dual-scale model was established based on Washburn capillary theory.

• The packing density of 0.01 g/cm³ was proposed as threshold value for KFP assembly used as a potential lubricant carrier.

Acknowledgements

The authors received no financial support for the research, authorship, and/or publication of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).