Two Powder Bed Processes With Different Engines
SLS and Multi Jet Fusion are both polymer powder bed fusion processes, but they fuse powder differently. SLS uses a laser to scan and sinter each cross-section. MJF applies fusing and detailing agents to the powder, then uses heat to fuse the selected areas.
Two Powder Bed Processes With Different Engines
SLS and Multi Jet Fusion are both polymer powder bed fusion processes, but they fuse powder differently. SLS uses a laser to scan and sinter each cross-section. MJF applies fusing and detailing agents to the powder, then uses heat to fuse the selected areas.
Both processes can produce functional nylon parts without conventional supports. The better choice depends on material, surface finish, throughput, color, cost, supplier access, and the performance requirements of the part.
Where SLS Wins
SLS is broadly available through service bureaus and machine ecosystems, and it has a long history in functional prototyping and small-batch production. It handles complex shapes, nested builds, PA12, PA11, filled nylons, and TPU-like flexible materials depending on supplier.
SLS can be a strong choice when material selection, established workflows, and broad vendor availability matter. It is also useful when a shop already has experience with SLS finishing, powder refresh, and dimensional behavior.
Where MJF Wins
MJF is often attractive for throughput, consistent batches, and production-oriented nylon parts. HP describes MJF and SLS as powder bed technologies with different tradeoffs in budget, mechanical properties, specs, and finishing needs.
MJF parts often have a gray appearance before dyeing and can offer strong productivity for batches. It may be the better choice when supplier pricing, repeatability, and volume align with the application.
Mechanical Properties and Detail
Both processes can produce useful functional parts, but properties depend on material, machine, orientation, post-processing, and supplier settings. Do not assume that all PA12 SLS and all PA12 MJF parts are identical simply because the material family is similar.
For critical parts, request data sheets from the supplier and test the actual geometry. Clips, thin walls, snap fits, living hinges, and threaded inserts all reveal process differences better than generic strength claims.
Cost and Production Volume
Cost depends on part size, packing density, material, finish, and provider. MJF may be competitive for larger batches because of its layer-wide agent and heat workflow, while SLS can be very economical for many complex low-volume jobs. The quote is usually more useful than a blanket rule.
If a design will be ordered repeatedly, compare pilot batches from both processes. Measure fit, surface, color, strength, and delivery time. A process that wins one prototype may not win a 500-part order.
Surface Finish and Appearance
SLS parts often have a natural powdery white or gray surface before finishing. MJF parts often arrive gray and are commonly dyed black. Both can be tumbled, dyed, sealed, or coated depending on the provider.
Cosmetic requirements can decide the process. If color uniformity, surface texture, or finishing workflow matters, request samples from the supplier before placing a production order.
Which Technology Wins
Neither technology wins every job. Choose SLS when material selection, established supplier options, flexible powder choices, or specific SLS design behavior fits the part. Choose MJF when the quote, throughput, batch consistency, and finish options fit the production plan better.
The smart comparison uses the same model, same finish expectation, same quantity, and same inspection criteria. Powder bed fusion decisions are practical manufacturing choices, not brand loyalty contests.
FAQ
Is MJF the same as SLS?
No. Both use polymer powder beds, but SLS uses a laser while MJF uses agents and heat to fuse selected areas.
Which is stronger, SLS or MJF?
It depends on material, machine, supplier, orientation, and finishing. Test the actual part when strength matters.
Which is cheaper, SLS or MJF?
Pricing depends on geometry, quantity, material, finish, and provider. MJF can be competitive for batches, while SLS remains strong for many low-volume complex parts.
