Selective laser sintering is a powder-bed fusion process in which a high-power laser — typically a CO₂ or Nd:YAG source — selectively scans each cross-sectional layer of a polymer powder bed, raising the local temperature to the melting point of the material and fusing individual particles together into a consolidated solid. As documented in the Tiger Coatings GmbH patent (2018), "in the SLS process, the first powder layer is evenly deposited on the stage by a roller, then heated to just below the melting point of the powder; thereafter, a laser beam is selectively scanned across the powder to locally raise the temperature to the melting point, fusing individual powder particles together." The surrounding, unsintered powder acts as a self-supporting structure, eliminating the need for dedicated support materials.

Multi Jet Fusion (MJF), commercialised by HP Inc., uses a full-width array of inkjet printheads to deposit two chemical agents — a fusing agent and a detailing agent — onto a powder bed that is then exposed to infrared energy across the entire surface simultaneously. The fusing agent absorbs IR radiation and generates heat locally to sinter the powder, while the detailing agent at part boundaries inhibits fusion. Unlike SLS, which uses a point-source laser that scans sequentially, MJF applies energy across the full layer width, processing all parts within a layer simultaneously.

The patent literature confirms these are functionally equivalent process categories. Xerox Corporation (2022) explicitly lists MJF alongside SLS, electron beam melting (EBM), binder jetting, and selective heat melting as alternative "local heating techniques" for powder particle consolidation — confirming that MJF occupies the same functional niche as SLS but uses a fundamentally different energy delivery architecture. Oxford Performance Materials characterises SLS as "a layer-wise additive manufacturing technique in which electromagnetic radiation, for example from a CO₂ laser, is used to bind a powder building material at select points to create a solid structure having a desired three-dimensional shape." For further context on powder-bed fusion standards, the ASTM International F42 committee maintains the authoritative classification framework.

Both processes eliminate support structures by using unsintered powder for geometric support — a shared advantage over filament extrusion (FDM) for complex end-use part design freedom. As described in the Huntsman crosslinkable powder patent (2023): "the surrounding powder supports the component geometry." Explore PatSnap's materials science intelligence to go deeper on polymer powder innovations.

Process temperature control is critical in both SLS and MJF. INEOS Styrolution specifies a build chamber temperature variation of no more than ±10% from the set processing temperature Tx for SLS, underscoring that dimensional accuracy and part isotropy in both technologies depend heavily on thermal uniformity. In MJF, uniform IR heating must be matched to consistent powder thermal response — an equally demanding requirement.

Both processes generate significant unused powder that must be refreshed with virgin material. SLS powder degradation from thermal cycling is a well-documented process engineering challenge; the controlled processing temperature regime described in INEOS Styrolution patents directly addresses powder refresh ratios. Understanding powder refresh economics is central to production cost modelling for either technology.

MJF's full-width agent deposition and simultaneous IR exposure enables higher volumetric build rates than single-laser SLS systems, making it preferable for high-volume end-use polymer production runs. Multi-laser SLS architectures partially close this gap, as reflected in process intensification research from TRUMPF (2019) on continuous and pulsed laser beam additive manufacturing. The NIST Additive Manufacturing programme provides independent benchmarking data on process parameter standards for both technologies. For IP analytics on production process patents, see PatSnap's IP analytics platform.

MJF imparts a characteristic grey coloration from the carbon-based fusing agent, while offering a somewhat smoother as-printed surface finish than SLS. SLS parts typically exhibit a slightly rougher, more granular surface. Both technologies require post-processing (bead blasting, tumbling, dyeing) for end-use surface quality, though MJF parts accept dye penetration more uniformly. For validated customer case studies on additive manufacturing production, see PatSnap customer success stories.