3D Printing & Photopolymer CAM

PolyJet Photopolymer Droplet & UV Pinning Calculator

Model piezoelectric printhead micro-droplet jetting dynamics, UV-LED pre-curing pinning dose, layer leveler blade flycutting, and multi-material Shore A gradient raster/vector slicing.

Process Parameters & Inputs

Piezo Nozzle Orifice Diameter (µm)

Micro-machined silicon or electroformed nickel nozzle orifice.

Droplet Ejection Velocity (m/s)

Piezoelectric acoustic pulse ejection speed (typical: 6 - 9 m/s).

Photopolymer Ink Dynamic Viscosity (mPa·s / cP)

Jetting temperature viscosity at 65°C - 75°C printhead manifold.

Liquid Surface Tension (mN/m)

Surface energy of acrylate photopolymer resin (typical: 28 - 34 mN/m).

UV-LED Pinning Irradiance (W/cm²)

Trailing 395nm UV-LED lamp peak irradiance for droplet freezing.

Printhead Carriage Scan Velocity (mm/s)

Raster scanning speed of jetting carriage over build tray.

Calculated Engineering Metrics

Droplet Volume

16.4pL

Ohnesorge Number (Oh)

0.48Stable

UV Pinning Energy Dose

27.7mJ/cm²

Nominal Layer Thickness

18.0µm

Toolpath & Geometry Simulation

Need Flawless DXF/SVG Contours for CAM?

SpotItLive converts technical drawings, raster graphics, and diagrams into clean, continuous vector paths ready for 5-axis CAM and CNC execution.

Convert to Scalable Vector →

Engineering Principles & Formula Reference

PolyJet and multi-jet photopolymer 3D printing jetted droplets are governed by fluid dimensionless numbers (Reynolds $Re$, Weber $We$, and Ohnesorge $Oh$) to ensure stable droplet formation without trailing satellites.

Droplet Fluid Dynamics & Pinning Dose

Stable DoD (Drop-on-Demand) jetting window requires $0.1 < Oh < 1.0$ and $We > 4$:

We = rac{
ho \cdot v^2 \cdot d_n}{\gamma}, \quad Re = rac{
ho \cdot v \cdot d_n}{\mu}, \quad Oh = rac{\sqrt{We}}{Re} = rac{\mu}{\sqrt{
ho \gamma d_n}}

E_{ ext{dose}} = rac{I_{ ext{UV}} \cdot W_{ ext{UV}}}{v_{ ext{scan}}} imes 1000 \quad ( ext{mJ/cm}^2)

UV-LED pinning rapidly increases resin viscosity to freeze droplet dot spread before full polymerization, enabling multi-material full-color and variable-durometer digital materials.