Yield stress is the minimum stress required to initiate flow in a material that behaves as a solid at rest, but flows like a liquid once a critical stress threshold is exceeded. It is used to characterize a wide range of structured fluids and soft solids across various industries. In food systems such as ketchup, yogurt, and mayonnaise, yield stress helps control pourability and spreadability. In cosmetics and personal care products, it ensures creams, gels, and lotions remain stable on the skin until rubbed or applied. Pharmaceutical suspensions rely on yield stress to prevent sedimentation during storage while allowing smooth application. In paints and coatings, it helps prevent dripping or sagging on vertical surfaces, and in construction materials like cement slurries and tile adhesives, it provides a balance between workability and structural stability.

Our rheology lab offers yield stress testing services using multiple methods tailored to the material’s behavior and intended application. The steady stress sweep method determines yield stress by gradually increasing the applied shear stress and identifying the point at which the material begins to flow. For viscoelastic systems, we also employ dynamic stress or strain sweep tests under oscillatory conditions to detect the onset of storage modulus decay—an indicator of structural breakdown and the transition from solid-like to flowable behavior. By combining these complementary techniques, we ensure accurate yield stress characterization across a broad spectrum of products and formulations.