VOF 3D simulation (Ansys fluent) How to get separated (0 or 1) Volume fraction values
 

Hi everyone,
Currently I am simulating a rectangular domain, in which I use VOF (volume of fluids) method, If I simulate it in 2D, after transient simulation, I got separated values of volume fraction between the fluids (Polyurethane as 1 and Air as 0 valules).
When I try to simulate the same field in 3D, after simulate the same ammount of steps, I got results in which values are not just 1 or 0 for the fluids, but I got a variety of values (as this fluids would not be inviscid). I am using the same settings for both simulations except of the gravity value setting.
I would like to ask you all if have any clue of setting the model in a better way in order to obtain right results.
Thanks so much for your great help in advance.