• • Comprehensive rheological data for PP, PE, PS, ABS and their binary blends (PE/ABS, PP/ABS, PS/ABS) were obtained across shear rates 0.1–100 s⁻¹ and temperatures 180–250°C, filling a critical data gap for process design.
• • All tested melts exhibited shear-thinning (n < 1), with PE showing the lowest flow behavior index and viscous flow activation energy, indicating highest shear sensitivity but lowest temperature sensitivity—critical for selecting processing conditions.
• • A modified power-law model incorporating a component correction term achieved an average relative error of only 5.90% between predicted and measured viscosities, enabling accurate viscosity estimation for multi-component plastic systems.
• • The viscosity of binary blends consistently fell between those of the pure components, and the model quantitatively captured the effect of mass fraction (0.5 < m ≤ 1) on viscosity, facilitating blend formulation and recycling process optimization.