文摘
One-dimensional axisymmetric fluid dynamics of a resin droplet was studied when it is squeezed between two parallel plates under the influence of UV (Ultraviolet) radiation curing. The radial spreading of different level of resin viscosity and its spreading speed are developed from the previous framework for viscous fluid dynamics of Newtonian fluid with negligible capillary number and Reynolds number. Then the final equations for spreading radius and spreading speed under the influence of UV curing are related with each other for the given spreading radius, viscosity at the corresponding elapsed time. The elapsed time increment could be assessed from the incremental elapsed time calculated from the incremental radius, assuming negligible viscosity change when the incremental radius is controlled to be small enough. The spreading of resin droplet is highly restricted by rapid viscosity rise due to crosslinking polymerization from UV curing. The theory was verified through droplet spreading tests with resin samples of different initial viscosities and of the same viscosity under different UV power. The theoretical prediction was in good agreement with the experimental results for both spreading radius and spreading speed. The same theoretical approach was then applied to the prediction of spreading boundary size and time to reach to it for a slow curing resin with different UV power intensity.