A ceramic nozzle is defined by a single feature: the orifice. Everything the part does — the spray pattern, the droplet size, the dosing rate — is set by the geometry of that bore and how stably it holds its shape in service. Where a metal or polymer nozzle is limited by how finely you can drill or erode a hole, a ceramic nozzle is formed with the orifice already shaped in the green body, so micron-level control comes from the mold rather than from post-machining. That is what lets the same component serve as a coating atomizer, a slurry feed or a precision dosing port. Browse the range on the CRAC ceramic nozzles product page.
What Actually Controls Spray and Dosing
Three dimensions of the orifice decide performance. The diameter sets the baseline flow and the maximum droplet size. The length-to-diameter (L/D) ratio sets how much the fluid is conditioned as it passes — a long, straight bore gives a coherent jet, while a short one gives a softer spread. The internal profile — taper, swirl chambers, conical entry — sets the pattern: flat-fan, full-cone, hollow-cone or spiral. Surface finish matters too: a smooth bore resists wetting and keeps the spray angle repeatable batch to batch. None of this is adjustable after sintering, so it has to be built into the part.
Why the Orifice Wears First
In most duties the orifice is where the fluid turns into a high-velocity jet, so it sees the highest impact and the most abrasive load. A metal orifice erodes into a ragged, enlarged hole; the spray angle drifts, the droplet size grows, and dosing accuracy falls. A ceramic orifice resists that erosion, so the bore edge stays sharp and the performance stays put. Low surface energy also means many ceramics resist wetting and clogging, which keeps flow consistent where sticky or fouling media would build up on metal.
Materials by Media and Pressure
The orifice tolerance and the pressure it must survive usually decide the grade. The table shows family-level behaviour for the nozzles CRAC produces.
| Property |
Alumina |
Zirconia (Y-TZP) |
ZTA blend |
| Min. orifice diameter | Tens of µm | Sub-100 µm feasible | Tens of µm |
| Bending strength | ≥600 MPa | ≥1000 MPa | ≥800 MPa |
| Hardness (Vickers) | ~1800 HV | ~1200 HV | ~1800 HV |
| Bore finish achievable | Smooth, low Ra | Smooth, low Ra | Smooth, low Ra |
| Best at | Cost-sensitive general use | High pressure, impact, thermal shock | Balanced wear + cost |
The grade choice is driven by pressure and abrasiveness first; our material classification guide and zirconia selection guide cover the trade-offs in depth.
Forming the Orifice Net-Shape
A nozzle bore is too small and too precise to drill or grind reliably at volume. CRAC forms it by precision ceramic injection molding: the powder-binder feedstock is injected so the orifice, taper and any swirl feature are created in one shot, then debound and sintered. Because the bore exists before sintering, concentricity and wall thickness are controlled by the tool, not by a secondary operation. The CIM process guide explains the steps; for unusual bore geometries the OEM/ODM program develops a custom tool from a drawing.
Performance You Can Measure
- Spray-angle stability – a stable orifice edge keeps the pattern within tolerance over the service life.
- Droplet-size distribution – repeatable bore geometry gives a consistent mean droplet size and a tight spread.
- Flow-coefficient repeatability – batches dose within a narrow band, important for metering.
- Erosion life – ceramic resists the jet-impingement wear that enlarges metal orifices.
- Chemical resistance – stable with acids, alkalis and solvents that attack metal nozzles.
Spray Patterns and Where They're Used
- Coating and surface treatment – flat-fan and full-cone patterns for even film build.
- Humidification and dispersion – fine, stable droplets for consistent particle conditioning.
- Grinding and milling feed – slurry dosing into bead mills and sand mills; see common bead-mill ceramic parts and ceramic dispersion discs.
- Pharmaceutical and food – inert, contamination-free dosing of sensitive media.
- Powder guidance – precise, wear-resistant control of abrasive powders.
How to Specify a Ceramic Nozzle
- Define the fluid – match the grade to the media's chemistry and abrasiveness.
- Set the orifice – diameter, L/D and internal profile set flow, pattern and droplet size.
- State the pressure and temperature – verify the grade against the duty limits.
- Set finish and tolerance – specify bore roughness and concentricity.
- Confirm custom features – swirl, taper or mounting can be built into the tool.
Quality and Customization
Nozzles are judged at the orifice, so CRAC inspects bore geometry and finish directly — bore microscopy and a flow test confirm the as-molded dimension, not just the outside shape. Orifice diameter, profile, material and mounting can all be customized. See how zirconia structural parts perform in extreme wear and how precision injection-molded zirconia parts are engineered for demanding service.
Frequently Asked Questions
How small an orifice can be held?
Net-shape molding lets CRAC hold sub-100 µm bores in zirconia with controlled wall thickness; the practical minimum depends on the grade and the required wall strength.
Do ceramic nozzles clog less than metal?
Their low surface energy and smooth bore resist wetting and fouling, so sticky or precipitating media tend to flow more consistently than on a metal orifice.
Which grade for a high-pressure abrasive slurry?
Zirconia for maximum toughness and impact resistance, ZTA where a cost-balanced wear profile is enough, alumina for mild, non-abrasive duty.
Can the spray pattern be customised?
Yes — flat-fan, cone and spiral patterns are set by the internal profile, which is built into the molded bore rather than machined.
Need a nozzle built around your orifice specification?
