At the same time, the reduced gas diffusion rate can minimize the cell ripening phenomenon. Consequently, a larger number of nucleated cells will last longer during cell growth, and the final expansion ratio of the foam products will also be promoted. Recently, Wong et al. proposed that at a very low processing temperature, the intercalated particles have greater rigidity and thereby can create a higher cell density because of the higher local stresses that are favorable for cell nucleation. In other words, better dispersion would not play a role but the rigidity of the intercalated particles would be of prime importance in generating more stress variations