Tools
Small, transparent calculations we use every day — free to use, with the formula shown. Results are estimates; check them against your own measurements.
01 · Coating
Nominal shear rate the slurry sees between the die lip (or blade) and the moving substrate.
γ̇ ≈ U / h (simple shear, Couette estimate)
Real flow in the die and coating bead is not simple shear; use this to choose which part of the flow curve to read.
02 · Formulation
Volume fraction controls viscosity far more directly than weight fraction.
Slurry density: — g/cm³ ·
φ = (w/ρₛ) / (w/ρₛ + (1−w)/ρₗ)
For multi-component solids, use a weighted average particle density. Binder dissolved in the liquid can be counted with the liquid.
03 · Prediction
Krieger–Dougherty estimate of how much solids raise viscosity over the liquid alone.
Estimated slurry viscosity: —
ηᵣ = (1 − φ/φₘ)^(−[η]·φₘ)
A hard-sphere estimate. Fine, irregular, interacting or poorly dispersed particles usually give more — and the size and pattern of that gap is exactly what a diagnostic review reads.
04 · Transfer
Shear rate at the wall of a transfer line or recirculation loop.
Mean velocity: — m/s
γ̇w = 32Q / (πD³) · v = 4Q / (πD²)
Newtonian estimate. For shear-thinning slurries the true wall shear rate is higher (Rabinowitsch correction).
All results are order-of-magnitude engineering estimates for orientation only. They are not a substitute for measurement, and nothing you enter here is stored or sent anywhere.
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