Study On Effect Of Resin Surface Tension And Viscosity On Soakage Velocity

Resin Transfer Molding (RTM) is a new advanced preparation method for composite material. RTM is widely used in many industries, such as airplane, automobile, machine, electronic industry, architecture and so on. RTM is a kind of close-molding techniques, during the molding the most important factor for the increasing properties of products is resin soakage to glass fiber. If air can't be excluded completely the product will have many defects and the properties of the product will be reduced especially in FRP. At the same time, RTM is also a kind of low-pressure molding techniques. It is different from the traditional molding techniques in which fiber is soaked more than once, resin soaks fiber just one time in RTM. RTM asks for good properties of resin, and it's flowage characteristic is very important. The resin flowage characteristic directly influences the resin soakage and the final properties of the products. So it is necessary to study on the factors of influencing soakage, to satisfy the resin soaking sufficiently and permeating the mold. Resin viscosity and surface tension are important factors influencing resin fiowage. This thesis mainly discussed the influence of the resin viscosity, surface tension and fiber content to the soakage velocity.The soakage of different viscosity resin using drone method was studied in this thesis. Choose different viscosity of unsaturated polyester to soak different glass fiber or felt, and do the real-time collection for the experiment. Then analysis the relation of the resin viscosity and surface tension to the soakage velocity on different thickness condition, and do numerical simulation to established formula.When unsaturated polyester soak anisotropy glass fibric, the velocity is different. In the direction of 45° the velocity is higher than in other directions. To isotropy glass felt, the soakage velocity tend to sameness. The soakage velocity reduce with the resin viscosity rising. When resin viscosity rise, the resin soakage is difficult and soakage velocity reduce. The soakage velocity rise with resin surface tension rising and the relation of the two is linearity. According the relations of the three factors the Darcy's law was amended and becomes more perfect.Basing on amended Darcy's law do numerical simulation to optimize techniques parameter in resin transfer molding, study on the relationship of the resin viscosity, surface tension, injection pressure and the soakage velocity in theory to get more correct result. Uncovering the soakage principle in RTM mold can optimize microstructure of the premolding object, reduce or avoid soakage limitation, improve molding simulate emulation and optimize molding parameter, and offer technique reference for the industry manufacture.