RHEOLOGY OF SCREEN PRINTING INK

       Rheological studies on printing inks (adhesion type inks) were carried out using various alkyd resin concentrations. Several properties of ink were investigated such as viscosity ,shear rate and shear stress. The effect of time and concentraton of alkyd resin on the viscosity was also studied and discussed at 25 c0 . The percentages of alkyd resin considered were  33, 28 and 23 wt%  for time range of 0–35 sec using  Rheology international R1:I:M   viscometer at different values of speed and spindles size . It was found that the printing ink viscosity decreases clearly with time and increases with alkyd resin concentration.Equation for the Rheological behavior of screen printing ink was predicted, which is the power law.It was found from n values that the screen printing ink behaves as a non-Newtonian pseudoplastic behavior, also the area of thixotropy was calculated which represents the cracking energy of the molecular bounds and reconstructing it which known as hystersis loop.