Designing shielding parts that print right the first time
A shielding part is only as good as its weakest path. Every void, thin wall or gap is where radiation gets through. These guidelines apply to both Rapid 3DShield materials.
Material settings
| Rapid 3DShield Tungsten | Rapid 3DShield Boron Carbide | |
|---|---|---|
| Stops | X-rays and gamma rays | Thermal neutrons |
| Loading | 88–94% tungsten | 50–60% boron carbide |
| Filament density | 7.80–9.20 g/cc | 1.30–1.50 g/cc |
| Binder | PLA-based; prints similar to PLA | PLA-based; prints similar to PLA |
| Nozzle | 0.8 mm hardened steel | 0.6 mm hardened steel |
| Drying | Do not dry (degrades the binder) | Do not dry (degrades the binder) |
| Sintering | None. Used as printed | None. Used as printed |
| Formats | 1.75 / 2.85 mm; 0.5, 1, 3, 5 kg spools; 1, 3, 5 kg pellets | 1.75 / 2.85 mm; 0.25, 0.5 kg spools; 1 kg pellets |
Density first
- Use 100% infill. Attenuation tracks mass per unit area, and infill voids are leak paths.
- Check your density. For tungsten, print the calibration model. It should weigh 5.5 g or more. If it's light, adjust flow and settings before printing real parts.
- Don't dry either material. Both are less hygroscopic than PLA, and drying degrades the binder.
Geometry
- Avoid straight-through seams. Where parts join, use steps, overlaps or labyrinth joints so no line of sight passes through the gap.
- Size walls from data. Printed tungsten needs roughly 2.1–2.5× the thickness of solid tungsten. Boron carbide absorbs thermal neutrons within a few millimetres (calculated). See the boron carbide guide.
- Design for handling. Green-state parts are sturdy enough to handle and install but aren't structural. Put load-bearing duty in a holder or bracket.
- Make large shields modular. Stackable or interlocking pieces print more reliably and are easier to check.
Printing
- Fit a hardened steel nozzle. Both materials are abrasive.
- Make sure the filament feeds straight into the extruder.
- Start from your PLA profile. Both materials print similar to PLA, with minimal to no warping.
- Check our Trusted Printers list and printing guide.
Working on a shielding program or ordering by PO? Email [email protected]. · Tungsten filament · Boron carbide filament