Selective Laser Sintering (SLS): Does SLS use laser-hardened liquid resins to build models, or does it fuse powdered materials layer by layer?

Introduction / Context:
Selective Laser Sintering (SLS) is a powder-bed fusion additive process. A laser scans and fuses particles (thermoplastics like PA12, elastomers, or even metal variants in related processes) layer by layer. The claim that SLS uses laser-hardened resins describes stereolithography (SLA), not SLS.

Given Data / Assumptions:

• We are comparing SLS (powder) and SLA (liquid photopolymer).
• Both use layer-wise fabrication with lasers, but materials and physics differ.
• Supports: SLS often relies on surrounding powder for support; SLA needs explicit support structures.

Concept / Approach:
In SLS, a recoater spreads a thin layer of powder; the laser fuses selected regions. The build lowers, a new layer is spread, and the process repeats. In SLA, a UV laser (or projector) cures liquid resin by photopolymerization. Confusing these leads to incorrect expectations about surface finish, mechanical properties, and post-processing.

Step-by-Step Solution:

Verification / Alternative check:
Observe build chambers: SLS has powder cakes; SLA has resin vats. Datasheets list nylon/elastomer powders for SLS vs photopolymers for SLA.

Why Other Options Are Wrong:
Options claiming photopolymers, support baths, or layer thickness as determinants confuse process fundamentals.

Common Pitfalls:
Expecting SLA-like glossy surfaces from SLS; overlooking powder recycling and thermal management; mishandling unsintered powder during depowdering.

Final Answer:
Incorrect