LAUSR

Abstract The oil bleed behavior of lithium complex, calcium sulfonate and polyurea thickened greases have been studied. Results were interpreted within a model where the grease thickener is treated as particles suspended in a matrix of oil. There is a region surrounding the thickener particles, called the effective media, which is assumed to have completely immobilized the oil. Bleed is assumed to occur from the viscous flow of the unbound oil in a porous structure made of the effective media. Dynamic/Static light scattering (DLS/SLS) techniques were used to assess the geometry of the thickener particles. In the light of this model different bleed behaviors of the greases were explained, relating them to the geometry of the thickener particles.