HP Nylon Multi-Jetting Fusion (MJF) 3D Printing: A Complete Guide

If you’re looking for a 3D printing technology that balances speed, precision, and cost for polymer parts, HP Nylon Multi-Jetting Fusion (MJF) 3D printing should be at the top of your list. Used by startups and large manufacturers alike, MJF stands out for its ability to make durable, functional parts—from prototypes to low-to-medium production runs. This guide breaks down how MJF works, its best materials, key advantages (and drawbacks), real-world uses, and how to decide if it’s right for your project.

How HP Nylon MJF 3D Printing Works (Step-by-Step)

MJF is a powder bed fusion technology, but it’s not the same as laser-based methods like SLS. Instead of a laser, it uses liquid agents and heat to fuse nylon powder into parts. Here’s a simple breakdown of its 5-step process:

1. Lay a Thin Powder Layer: The printer’s build platform lowers slightly, and a printhead spreads a thin (80-micron) layer of nylon powder across the bed. This thin layer ensures high detail and smooth finishes.
2. Apply Liquid Agents: An inkjet head moves over the powder, depositing two key agents:

• Fusion Agent: This liquid helps the powder melt when heated.
• Refiner Agent: This defines the part’s precise edges—keeping unneeded powder loose and ensuring dimensional accuracy.

3. Heat to Fuse: A heating unit passes over the bed. The powder with fusion agent melts and bonds together to form the part’s layer. The refiner agent keeps surrounding powder unmelted (this acts as support, so no extra supports are needed).
4. Repeat Layers: The build platform lowers again, and the process repeats (new powder layer → agents → heat) until the part is complete.
5. Clean and Reuse Powder: After printing, the entire powder bed moves to a processing station. Unmelted powder is vacuumed away—over 50% of it can be reused—reducing waste and cost. The finished part is then cleaned to remove any remaining loose powder.

HP Nylon MJF 3D Printing Materials: What You Can Use

MJF works best with specific polymer powders—focused on durability and functionality. While it doesn’t have the widest material range, the options it offers cover most industrial and consumer needs. Here’s a breakdown:

Note: Unlike FDM (which uses filaments like ABS or PLA), MJF is limited to these nylon and TPU powders. It can’t handle resin, food-grade materials, or other specialty plastics—something to keep in mind if your project needs unique materials.

Key Advantages of HP Nylon MJF 3D Printing

MJF isn’t just popular by accident—it solves big pain points for designers and manufacturers. Here are its most impactful benefits, with real-world examples to back them up:

1. No Support Structures Needed (Saves Time and Money)

Since MJF uses loose powder as support for overhangs or hollow parts, you never need to design or remove support structures. This cuts post-processing time by 30–50% compared to FDM (which often requires cutting away plastic supports).

Example: A bike accessories brand used MJF to print Apple AirTag bicycle mounts. The mount had a hollow interior (to hold the AirTag) and an overhang to attach to the bike frame. With MJF, they printed the part in one go—no supports to trim. FDM would have required supports inside the hollow, which would be hard to remove without damaging the part.

2. Full-Color Functional Parts (Rare for Engineering-Grade Plastics)

MJF is one of the few 3D printing technologies that can print full-color, engineering-grade nylon parts (like PA12) while keeping their strength. It uses a voxel control system (controlling tiny 3D pixels) to apply color precisely—great for parts that need both function and branding.

Use Case: A consumer electronics company made custom speaker grilles with MJF. The grilles were printed in the brand’s signature blue, had a lattice structure (for sound quality), and were strong enough to withstand daily use. Traditional methods (like painting FDM parts) would have chipped or faded—MJF’s color is integrated into the powder, so it doesn’t wear off.

3. Strong, Isotropic Parts (Good for Functional Use)

MJF parts are isotropic—meaning they’re strong in all directions (not just along layers, like FDM). This is because the fusion agent and heat create a uniform bond between powder particles. MJF parts also have low porosity (thanks to 80-micron layers), making them dense and durable.

Data Point: Tests show MJF PA12 parts have a tensile strength of 50 MPa—comparable to injection-molded PA12. This makes them ideal for load-bearing parts, like small automotive components.

4. Fast Lead Times (Faster Than SLS for Medium Batches)

MJF prints faster than SLS (another powder bed technology) because it can cover more area at once with its inkjet head (vs. a single laser in SLS). For medium batches (100–500 parts), MJF cuts lead times by 20–30%.

Example: A startup needed 200 prototype drone frames (PA12). SLS would have taken 6 days to print—MJF finished the job in 4 days, letting the team test the frames sooner and speed up product launch.

5. Low Waste (Over 50% Material Reuse)

As mentioned earlier, MJF reuses over 50% of its unmelted powder. This is a huge win for sustainability and cost—especially compared to CNC machining (which wastes 50–70% of raw material) or FDM (which can’t reuse filament scraps easily).

Impact: A medical device manufacturer using MJF for surgical guides reduced material costs by 25% in one year—just by reusing powder. They also cut their environmental footprint, as less waste went to landfills.

Disadvantages of HP Nylon MJF 3D Printing (What to Watch For)

MJF isn’t perfect—here are the main drawbacks to consider before choosing it:

1. Limited Material Options

MJF only works with nylon PA11, PA12, and TPU M95A. If your project needs ABS, PETG, resin, or food-grade plastics, you’ll have to use FDM, SLA, or another technology.

Example: A toy company wanted to print kid-safe, food-grade snack containers. MJF’s materials aren’t food-safe, so they switched to FDM with PLA (which is food-grade).

2. Slightly Rough Surface Finish (Needs Post-Processing for Smoothness)

While MJF parts have a better natural finish than SLS, they’re still slightly rough (like fine sandpaper) compared to resin-based technologies (SLA) or CNC-machined parts. If you need a glossy or ultra-smooth surface, you’ll have to add post-processing steps (like media polishing or vapor fusion)—which adds time and cost.

Cost Impact: Post-processing a batch of 100 MJF parts for a smooth finish can add \(2–\)5 per part, depending on the complexity.

How HP Nylon MJF Compares to Other 3D Printing Technologies

Wondering how MJF stacks up against FDM (the most common) and SLS (its closest powder bed cousin)? This table breaks down the key differences:

Yigu Technology’s Perspective on HP Nylon MJF 3D Printing

At Yigu Technology, HP Nylon MJF is our go-to for clients needing functional, medium-batch polymer parts. We often recommend it for prototypes that need to mimic final production parts (like PA12 automotive brackets) or full-color components (like branded consumer goods). We help clients navigate MJF’s material limits—if TPU or nylon works for their project, MJF’s speed and low waste deliver great value. We also offer post-processing (polishing, vapor fusion) to fix surface roughness, ensuring parts meet both functional and aesthetic needs. For us, MJF is all about balancing performance and practicality—helping clients get durable parts fast, without overspending.

FAQ About HP Nylon MJF 3D Printing

1. Can HP Nylon MJF parts be used for outdoor applications?

Yes—nylon PA11 and PA12 are UV and weather-resistant, making MJF parts great for outdoor use (e.g., bike mounts, outdoor gear). Just note that TPU M95A may degrade over time in direct sunlight, so stick to nylon for long-term outdoor parts.

2. Is HP Nylon MJF more expensive than FDM?

For small batches (1–10 parts), FDM is cheaper (FDM parts cost \(15–\)20 each, vs. \(20–\)25 for MJF). But for medium batches (100–500 parts), MJF becomes cost-competitive—its faster speed and material reuse lower per-part costs to \(12–\)16, while FDM stays at \(18–\)20 per part.

3. Can HP Nylon MJF print large parts?

MJF’s max build volume is around 380×284×380 mm—smaller than FDM (which can print parts up to 914×610×914 mm) or CNC machining. If you need parts larger than MJF’s build volume, you’ll have to print them in sections and assemble them (which adds time) or use another technology.