Volumetric Dispensing Pressure Drops and Dynamic Viscosity Profiles in Automation Lines
Automated volumetric dispensing accuracy depends on balancing line pressure drops against non-Newtonian shear thinning profiles across operating flow rates.
Static Mixer Pressure Loss
Meaning
Reduction in fluid pressure that occurs as a material passes through a stationary mixing element. Static mixer pressure loss is caused by the internal baffles that force the two components of an adhesive to fold and combine. It represents the energy required to achieve a homogenous mixture.
Mixing Efficiency
Increasing the number of elements improves the blend quality but also raises the resistance. Each additional flight in the tube contributes to the total static mixer pressure loss. Operators must find the minimum number of elements that satisfy the mixing requirements without exceeding the pressure limits of the pump.
Temperature Effect
Viscosity changes significantly with thermal fluctuations, which directly alters the flow resistance. Higher temperatures lower the fluid thickness and result in a smaller static mixer pressure loss. Cooling the material can have the opposite effect, potentially stalling the motor or causing a hose failure.
Flow Regulation
Accurate dosing depends on the pump being able to overcome the downstream resistance consistently. Because the static mixer pressure loss varies with the square of the flow rate in some regimes, small changes in speed can cause large pressure spikes. Monitoring this value helps in detecting the onset of curing inside the mixer.