3DPOD 314: Debinding, Sintering, and Metal Binder Jetting with Stefan Joens, Elnik Systems and DSH Technologies

Key Takeaways

• Elnik Systems supplies high‑temperature debinding and sintering ovens that handle up to 1,200 kg of metal parts per batch.
• Typical sintering cycles for stainless‑steel binder‑jet parts run 10–12 h at 1,250 °C, achieving ≈99.5 % theoretical density.
• Binder jetting excels for complex geometries up to 300 mm in height, but shrinkage (≈ 15 % linear) demands precise CAD compensation.
• Compared with bound‑filament extrusion, binder jetting offers 10‑20× faster build rates and superior surface finish, yet requires a dedicated post‑process line.
• Future developments focus on in‑situ debinding ovens and hybrid powder‑bed‑fusion/binder‑jet systems to close the gap between design freedom and material performance.

Introduction

The 3DPOD episode 314 brings together Stefan Joens, senior sales director at Elnik Systems, and representatives from DSH Technologies to unpack the full workflow of metal binder‑jet printing—from powder deposition to final sintered part. The discussion provides a practical roadmap for manufacturers seeking to scale binder‑jet production while maintaining tight tolerances and repeatable material properties.

Elnik Systems: From Foundry Roots to Additive‑Manufacturing Ovens

Founded in 1998 as a supplier of industrial furnaces for traditional powder metallurgy, Elnik leveraged its metallurgical expertise to develop dedicated debinding and sintering ovens for additive manufacturing. The flagship E‑Sinter 1500 series can reach 1,500 °C, sustain a uniform temperature gradient of less than ±2 °C across a 2 m³ chamber, and integrate programmable vacuum or inert‑gas atmospheres (argon, nitrogen).

These ovens are engineered for continuous‑flow operation, allowing a new batch to be loaded every 30 min without compromising thermal stability—a key advantage for high‑volume binder‑jet lines.

The Binder‑Jetting Process: From Green Part to Metal

1. Powder Deposition & Binder Printing

• Powders: 15–45 µm stainless steel (316L), tool steel (H13), or nickel‑based alloys.
• Binder: Water‑based polymer with a solids content of 30 wt %.
• Layer thickness: 50–100 µm, enabling build heights up to 300 mm in a single run.

2. Debinding

The green part is first heated to 350 °C (for polymer burnout) under a vacuum or nitrogen purge to avoid oxidation. A typical debind cycle lasts 4–6 h, removing ≈ 95 % of the binder mass.

3. Sintering

After debinding, the part enters the sintering oven at 1,150–1,250 °C for 10–12 h, depending on alloy and desired density. Controlled cooling (≤ 5 °C/min) minimizes residual stresses. The result is a near‑net‑shape metal component with ≥ 99 % theoretical density and tensile strength within 5 % of wrought material.

4. Shrinkage Management

Linear shrinkage averages 14–16 %, with anisotropy up to 2 % between the build and transverse directions. Modern CAD tools now embed a shrinkage compensation factor (typically 1.15) directly into the STL file, reducing post‑process machining time by 30–40 %.

Where Binder Jetting Shines – And Where It Falters

Comparing Binder Jetting to Bound‑Filament Extrusion