Flat-fan nozzles arrayed in a manifold header are the standard choice for uniform film coating on moving webs, strip, and conveyor lines. They produce a controlled fan-shaped spray with a defined width and relatively flat distribution curve, making them easy to overlap for full-width coverage. Nozzle spacing, stand-off distance, operating pressure, and the nozzle's spray angle and orifice size must all be matched to your target coat weight and line speed. Hydraulic atomizing nozzles are preferred when coat weights are very low or when fine droplet size is needed to minimize impingement effects.

Overspray reduction in coating systems comes from several sources: right-sizing orifice diameter to match the required flow rate at the lowest pressure that maintains pattern integrity, minimizing stand-off distance to reduce drift (especially with fine droplets), using electrostatic assistance when applicable, and ensuring nozzle on/off gating is properly synchronized with line start/stop events. Hydraulic atomizing nozzles at minimum operating pressure produce larger droplets with less tendency to drift than higher-pressure operation. Air-atomizing nozzles offer the most droplet size control and can reduce overspray significantly compared to hydraulic nozzles for viscous materials.

In many cases, yes—provided the nozzle body and seal materials are chemically compatible with both coating systems. 316L stainless steel nozzle bodies are compatible with most water-based and many solvent-based coatings. The critical check is seal compatibility: EPDM and silicone seals have limited resistance to aromatic and ketone solvents, while PTFE and Viton seals offer broader solvent resistance. Always verify seal compatibility against your specific solvent chemistry before switching between fluid types.

For coating fluids containing abrasive particles, fillers, or pigments, hardened orifice materials are essential to maintain accurate flow rates and spray pattern quality over time. Tungsten carbide (TC) orifice inserts provide the highest wear resistance and are preferred for heavily loaded abrasive systems. Ceramic inserts offer good wear resistance at lower cost for moderate abrasion levels. Standard stainless steel orifices will enlarge progressively in abrasive service, causing flow rate creep and pattern distortion. The nozzle body material (stainless, polymer) is less critical than the orifice for abrasion resistance.

Coating manifold design starts with your required coat weight (g/m²), line speed (m/min), and web or surface width. These define the total fluid flow rate needed per meter of width. Divide by the number of nozzles per meter to get individual nozzle flow rate. Then select a nozzle orifice size that delivers that flow rate at an appropriate operating pressure for your fluid viscosity. Stand-off distance sets the spray width per nozzle; spacing is then set so adjacent nozzle spray widths overlap by 10–30%. NozzlePro application engineers can work through this calculation with your specific parameters and recommend a nozzle model and manifold configuration.

Hydraulic atomizing nozzles use fluid pressure alone to break the liquid into droplets. They are simpler, require no compressed air supply, and work well for low-to-medium viscosity fluids at moderate coat weights. Air-atomizing nozzles use compressed air to atomize the liquid, providing much greater control over droplet size across a wider viscosity range, and can apply very low coat weights with fine, consistent droplets. Air-atomizing nozzles are preferred for high-viscosity coatings, very fine films, or applications where droplet size uniformity is critical. They require a compressed air supply and have higher operating cost than hydraulic nozzles but offer significantly more process flexibility.