1. College of Mechanical and Electronics Engineering, Guizhou Minzu University, Guiyang 550025, China
2. College of Mechanical and Electronics Engineering, Chongqing University of Arts and Sciences,Chongqing 402160, China
In this paper, the dynamic wetting process of natural flax plant fiber used as composite reinforcement is analyzed, the surface morphology of plant fiber and its preimpregnated fiber yarn is observed. The wetting characteristics of plant fiber with different liquid systems (DI water, epoxy resin) are discussed, and compared with the dynamic wetting process of widely used glass fiber. Based on Wilhelmy method, a new quantitative judgment method to identify the inherent roughness level of fiber reinforcement surface is proposed by establishing the dynamic wetting system and wetting mechanic model of fiber and resin at very low rate, combined with the stream function and the roughness theory of arithmetical mean deviation of the surface profile midline, and using the variance analysis technology. The adhesion work of flax plant fiber and glass fiber with wetting liquids was analyzed and discussed. The results show that, as composite reinforcements, the surface roughness factor of flax plant fiber is bigger and the wetting force/adhesion work of flax plant fiber in the dynamic wetting process are smaller. At the same condition, flax plant fiber has poor wetting performance compared with glass fiber.