The investigation and research has been performed, studying the liquid behavior of
chemically modified starch as the coating solution on urea surface with a CCD high
speed camera. The main aim ofthis study is to analyze the important parameters or
factors that will result the maximum spreading diameter of coating solutions on urea
surface.
There are main several factors that lead to the expected result, which are the effect of
droplet impact velocity and the droplet viscosity. Besides, the blending ratio also one of
the factors can determine the spreading diameter. Different type of solutions can give
the different characteristics, features and the value ofparameters.
Since this project dealing with urea as the solid substrate, study on urea surface
roughness and porosity is important in order to identify what are the behavior of droplet
will lead to the maximum spreading diameter and coating uniformity
