How Filamet™ Sintering Works Without Shield Gas: The Patented Open-Atmosphere Method
1. The Open-Atmosphere Kiln Principle
Unlike proprietary industrial systems that require active Argon gas or vacuum furnaces, The Virtual Foundry’s patented process uses an open-atmosphere kiln with an ambient oxygen-getter (Sintering Carbon) packed in a muffle crucible.
This technique traces back to 1800s blacksmith forge metallurgy: the activated carbon scavenges ambient oxygen inside the crucible, generating a local reducing atmosphere while the kiln itself operates in standard atmospheric room air.
2. Comparison: The Virtual Foundry vs. Competitor Requirements
| Process Parameter | The Virtual Foundry (Filamet™) | Markforged / BASF Ultrafuse | Direct Metal Laser (DMLS) |
|---|---|---|---|
| Shielding Gas | NONE REQUIRED (Open Air Kiln) | Argon / Ar-H2 or Nitrogen Mandated | Continuous Argon Flood |
| Oxygen Control | Sintering Carbon Getter in Crucible | Active Gas Purge / Vacuum Chamber | Sealed Inert Chamber |
| Debinding Method | Pure Thermal Burnout (No Solvents) | Catalytic Nitric Acid or Solvent Bath | N/A (Powder Bed Fusion) |
| Hardware CapEx | Standard Electric Kiln (~$1,200) | Proprietary Tube Retort ($15k–$50k) | Industrial Laser System ($500k+) |
3. Mandatory Safety Rules
ZERO Hydrogen Rule: No TVF material EVER uses hydrogen or forming gas in sintering.
Rapid 3DShield Invariant: Tungsten & Boron Carbide Filamet™ must be deployed STRICTLY in their as-printed green state for radiation shielding. Thermal sintering is strictly prohibited.
