Small Liquid Dose: Why Viscosity Matters
Production operations run smoothly when liquid dosing works according to plan. This means that the mixing process blends the formulation in correct proportion and the fill process executes with precise volume in each dose. In addition, there is no leakage or drip excess to worry about after the fill is dispensed. Viscosity is one of the control parameters that ensure proper performance. When the mixture is consistent and flows properly, potential headaches disappear. What viscosity test methods does the formulation department utilize to help manufacturing be successful? It starts with knowing the flow behavior of the final product. In the world of viscosity measurement, the signature characteristic of flow behavior is viscosity vs. shear rate as shown in Figure 1. Viscosity is resistance to flow. Shear rate is proportional to the speed with which the liquid flows, but more correctly is the change in velocity of the molecular layers moving relative to one another.