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Nozzle Design
Surface Finish Our smooth surface finish decreases the thickness of the boundary layer at the fluid wall interface, alleviating obstruction and reducing the propensity to clog with filled fluids. In contrast, a rough interior surface increases the width of the boundary layer at the fluid-wall interface, effectively acting to impede flow to some extent and encourage communication between particles in filled fluids.
Thin Walls In an environment where communication is encouraged, filled fluids have a much greater propensity toagglomerate and clog the exit aperture. Thus, thin walls with smooth surfaces are advantageous. This is a critcal consideration when the intent is to target difficult applications that require precise exit apertures with minimumfacial area exposure.
Thin vertical walls around the circumference
Coatings and Finishes Nozzle cores may be used uncoated or coated. Nickel silver is generally used in uncoated core applications, primarily for adhesives. Phosphor bronze or nickel silver base metals may be used for coated nozzle cores. Either metal can have electroless nickel or entecoat applied, and both coatings are hard and resistant to abrasion.
Entecoat, which is a nickel alloy composite with a matrix comprised of nickel and polytetrafluoroethylene (PTFE), is preferred for biomedical applications when combined with phosphor bronze base metal.
This coating can be deposited with extreme accuracy. Coverage is completely uniform on all surfaces of the nozzle core, and is non-stick with hydrophobic properties that can further alleviate effects from wicking. Entecoat exhibits the greatest beneficial effect when used with aqueous-based fluids. |
