Multi Jet Fusion (MJF) is HP’s proprietary powder bed fusion 3D printing technology that has rapidly transformed industrial additive manufacturing since its introduction in 2016. MJF uses an inkjet array to selectively apply fusing and detailing agents onto a bed of polymer powder, then passes an energy source over the surface to fuse the material. The result is production-grade nylon parts with excellent mechanical properties, fine detail, and throughput that challenges traditional manufacturing for low-to-medium volume production.
How Multi Jet Fusion (MJF) Works
The MJF process starts with a thin layer of polymer powder (typically PA12 nylon) spread across the build platform. An inkjet carriage passes over the powder bed, depositing two types of agents: a fusing agent on areas that will become the part, and a detailing agent around the edges to sharpen boundaries and improve feature resolution. An infrared energy source then passes over the entire bed, causing areas with fusing agent to absorb more energy and melt, while areas with detailing agent (or no agent) remain cool and un-sintered. After each layer, the build platform lowers, fresh powder is spread, and the process repeats. The result is a fully fused, near-isotropic nylon part embedded in a cake of loose powder — no support structures required.
Key Advantages of Multi Jet Fusion
Production-Ready Speed and Throughput
MJF processes entire layers at once, rather than point-by-point like laser-based SLS. This parallelism enables significantly faster build speeds — typically 2-5× faster than SLS for the same part geometry. Combined with high packing density, MJF can produce hundreds of parts per build cycle, making it viable for serial production.
Excellent Part Quality and Consistency
MJF produces parts with consistent mechanical properties throughout the build volume. Parts exhibit near-isotropic behavior with minimal variation between X, Y, and Z axes. Surface finish is smoother than standard SLS, with a matte gray appearance that can be dyed, painted, or vapor-smoothed.
Fine Feature Resolution
The detailing agent enables sharper edges, thinner walls, and better small-feature definition compared to traditional SLS. Minimum wall thicknesses of 0.5 mm and minimum feature sizes of 0.5 mm are achievable, with high repeatability across production runs.
Cost-Effective for Production Volumes
The combination of fast build speeds, high packing density, and material efficiency (up to 80% powder reusability) makes MJF one of the most cost-effective additive manufacturing technologies for production runs of 50-10,000+ parts.
MJF 3D Printing Materials
| Material | Key Properties | Typical Applications |
|---|---|---|
| HP 3D High Reusability PA12 | Tensile 48 MPa, chemical resistant, 80% reusability | General-purpose functional parts, housings, brackets, consumer goods |
| HP 3D High Reusability PA11 | High ductility, impact resistant, bio-derived | Living hinges, snap-fits, impact-resistant components, prosthetics |
| HP 3D High Reusability PA12 GB | Glass bead filled, high stiffness, low warpage | Structural housings, fixtures, tooling, rigid assemblies |
| HP 3D High Reusability PP | Polypropylene-like, chemical resistant, weldable | Automotive ducts, fluid containers, medical devices |
| Estane TPU (BASF) | Flexible, rubber-like, high rebound | Footwear midsoles, flexible grips, cushioning, protective gear |
Common Applications of Multi Jet Fusion
- Serial Production: Low-to-medium volume production of end-use parts, replacing injection molding for volumes from 50 to 10,000+ units
- Automotive: Interior trim components, HVAC ducts, mounting brackets, custom tooling, spare parts on demand
- Consumer Products: Wearable device housings, sporting goods components, customized accessories
- Medical and Healthcare: Prosthetic sockets, orthotic devices, surgical instrument handles, anatomical models
- Industrial Equipment: End-of-arm tooling for robotics, jigs and fixtures, conveyor components
- Drones and Aerospace: Lightweight structural brackets, ducting, housing assemblies
MJF vs SLS and Other Technologies
MJF and SLS share the fundamental advantage of support-free printing with nylon materials, but MJF offers superior speed, better surface finish, and more consistent mechanical properties across the build volume. SLS has a wider range of available materials (including carbon-filled, aluminum-filled, and specialty nylons) and lower entry costs for small-scale operations. Compared to FDM, MJF provides dramatically better surface finish and mechanical isotropy. Against SLA, MJF parts are stronger and more durable but with rougher surface texture.
Frequently Asked Questions
What is the typical build volume for Multi Jet Fusion?
The HP Jet Fusion 5200 series offers build volumes of 380 × 284 × 380 mm. The larger HP Jet Fusion 5420W extends to 380 × 380 × 380 mm. These build volumes can accommodate hundreds of small parts or several large components in a single build cycle.
How does MJF part cost compare to injection molding?
For volumes under 1,000 units, MJF is typically more cost-effective than injection molding due to the elimination of tooling costs ($5,000-$100,000+ for molds). At volumes between 1,000-10,000, MJF and injection molding costs converge depending on part complexity. Above 10,000 units, injection molding generally becomes more economical for simple geometries.
Can MJF parts be post-processed?
Yes, MJF parts can be dyed (most common, achieving uniform black or colored finishes), vapor-smoothed (for a sealed, glossy surface with improved mechanical properties), painted, electroplated, or media-blasted for different surface textures. Dyeing is particularly effective as MJF parts are naturally porous and absorb dyes evenly.
What is MJF printing lead time?
Standard lead times for MJF parts range from 5-8 business days. Full-build production cycles take 18-24 hours, followed by cooling (typically overnight) and post-processing (powder removal, bead blasting, dyeing if required). Rush services can deliver within 2-4 business days for urgent projects.